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From: David Malcolm <dmalcolm@redhat.com>
To: gcc-patches@gcc.gnu.org
Cc: David Malcolm <dmalcolm@redhat.com>
Subject: [PATCH 2/3] diagnostics: add support for "text art" diagrams
Date: Wed, 31 May 2023 14:06:29 -0400	[thread overview]
Message-ID: <20230531180630.3127108-3-dmalcolm@redhat.com> (raw)
In-Reply-To: <20230531180630.3127108-1-dmalcolm@redhat.com>

Existing text output in GCC has to be implemented by writing
sequentially to a pretty_printer instance.  This makes it
hard to implement some kinds of diagnostic output (see e.g.
diagnostic-show-locus.cc).

This patch adds more flexible ways of creating text output:
- a canvas class, which can be "painted" to via random-access (rather
that sequentially)
- a table class for 2D grid layout, supporting items that span
multiple rows/columns
- a widget class for organizing diagrams hierarchically.

The patch also expands GCC's diagnostics subsystem so that diagnostics
can have "text art" diagrams - think ASCII art, but potentially
including some Unicode characters, such as box-drawing chars.

The new code is in a new "gcc/text-art" subdirectory and "text_art"
namespace.

The patch adds a new "-fdiagnostics-text-art-charset=VAL" option, with
values:
- "none": don't emit diagrams (added to -fdiagnostics-plain-output)
- "ascii": use pure ASCII in diagrams
- "unicode": allow for conservative use of unicode drawing characters
(such as box-drawing characters).
- "emoji" (the default): as "unicode", but potentially allow for
conservative use of emoji in the output (such as U+26A0 WARNING SIGN).
I made it possible to disable emoji separately from unicode as I believe
there's a generation gap in acceptance of these characters (some older
programmers have a visceral reaction against them, whereas younger
programmers may have no problem with them).

Diagrams are emitted to stderr by default.  With SARIF output they are
captured as a location in "relatedLocations", with the diagram as a
code block in Markdown within a "markdown" property of a message.

This patch doesn't add any such diagram usage to GCC, saving that for
followups, apart from adding a plugin to the test suite to exercise the
functionality.

One issue is that in various places in the seltftests I've embedded
UTF-8 encoded characters in the source code.  Is that acceptable, or
do I need to e.g. move those tests to DejaGnu?

contrib/ChangeLog:
	* unicode/gen-box-drawing-chars.py: New file.
	* unicode/gen-combining-chars.py: New file.
	* unicode/gen-printable-chars.py: New file.

gcc/ChangeLog:
	* Makefile.in (OBJS-libcommon): Add text-art/box-drawing.o,
	text-art/canvas.o, text-art/ruler.o, text-art/selftests.o,
	text-art/style.o, text-art/styled-string.o, text-art/table.o,
	text-art/theme.o, and text-art/widget.o.
	* color-macros.h (COLOR_FG_BRIGHT_BLACK): New.
	(COLOR_FG_BRIGHT_RED): New.
	(COLOR_FG_BRIGHT_GREEN): New.
	(COLOR_FG_BRIGHT_YELLOW): New.
	(COLOR_FG_BRIGHT_BLUE): New.
	(COLOR_FG_BRIGHT_MAGENTA): New.
	(COLOR_FG_BRIGHT_CYAN): New.
	(COLOR_FG_BRIGHT_WHITE): New.
	(COLOR_BG_BRIGHT_BLACK): New.
	(COLOR_BG_BRIGHT_RED): New.
	(COLOR_BG_BRIGHT_GREEN): New.
	(COLOR_BG_BRIGHT_YELLOW): New.
	(COLOR_BG_BRIGHT_BLUE): New.
	(COLOR_BG_BRIGHT_MAGENTA): New.
	(COLOR_BG_BRIGHT_CYAN): New.
	(COLOR_BG_BRIGHT_WHITE): New.
	* common.opt (fdiagnostics-text-art-charset=): New option.
	(diagnostic-text-art.h): New SourceInclude.
	(diagnostic_text_art_charset) New Enum and EnumValues.
	* configure: Regenerate.
	* configure.ac (gccdepdir): Add text-art to loop.
	* diagnostic-diagram.h: New file.
	* diagnostic-format-json.cc (json_emit_diagram): New.
	(diagnostic_output_format_init_json): Wire it up to
	context->m_diagrams.m_emission_cb.
	* diagnostic-format-sarif.cc: Include "diagnostic-diagram.h" and
	"text-art/canvas.h".
	(sarif_result::on_nested_diagnostic): Move code to...
	(sarif_result::add_related_location): ...this new function.
	(sarif_result::on_diagram): New.
	(sarif_builder::emit_diagram): New.
	(sarif_builder::make_message_object_for_diagram): New.
	(sarif_emit_diagram): New.
	(diagnostic_output_format_init_sarif): Set
	context->m_diagrams.m_emission_cb to sarif_emit_diagram.
	* diagnostic-text-art.h: New file.
	* diagnostic.cc: Include "diagnostic-text-art.h",
	"diagnostic-diagram.h", and "text-art/theme.h".
	(diagnostic_initialize): Initialize context->m_diagrams and
	call diagnostics_text_art_charset_init.
	(diagnostic_finish): Clean up context->m_diagrams.m_theme.
	(diagnostic_emit_diagram): New.
	(diagnostics_text_art_charset_init): New.
	* diagnostic.h (text_art::theme): New forward decl.
	(class diagnostic_diagram): Likewise.
	(diagnostic_context::m_diagrams): New field.
	(diagnostic_emit_diagram): New decl.
	* doc/invoke.texi (Diagnostic Message Formatting Options): Add
	-fdiagnostics-text-art-charset=.
	(-fdiagnostics-plain-output): Add
	-fdiagnostics-text-art-charset=none.
	* gcc.cc: Include "diagnostic-text-art.h".
	(driver_handle_option): Handle OPT_fdiagnostics_text_art_charset_.
	* opts-common.cc (decode_cmdline_options_to_array): Add
	"-fdiagnostics-text-art-charset=none" to expanded_args for
	-fdiagnostics-plain-output.
	* opts.cc: Include "diagnostic-text-art.h".
	(common_handle_option): Handle OPT_fdiagnostics_text_art_charset_.
	* pretty-print.cc (pp_unicode_character): New.
	* pretty-print.h (pp_unicode_character): New decl.
	* selftest-run-tests.cc: Include "text-art/selftests.h".
	(selftest::run_tests): Call text_art_tests.
	* text-art/box-drawing-chars.inc: New file, generated by
	contrib/unicode/gen-box-drawing-chars.py.
	* text-art/box-drawing.cc: New file.
	* text-art/box-drawing.h: New file.
	* text-art/canvas.cc: New file.
	* text-art/canvas.h: New file.
	* text-art/ruler.cc: New file.
	* text-art/ruler.h: New file.
	* text-art/selftests.cc: New file.
	* text-art/selftests.h: New file.
	* text-art/style.cc: New file.
	* text-art/styled-string.cc: New file.
	* text-art/table.cc: New file.
	* text-art/table.h: New file.
	* text-art/theme.cc: New file.
	* text-art/theme.h: New file.
	* text-art/types.h: New file.
	* text-art/widget.cc: New file.
	* text-art/widget.h: New file.

gcc/testsuite/ChangeLog:
	* gcc.dg/plugin/diagnostic-test-text-art-ascii-bw.c: New test.
	* gcc.dg/plugin/diagnostic-test-text-art-ascii-color.c: New test.
	* gcc.dg/plugin/diagnostic-test-text-art-none.c: New test.
	* gcc.dg/plugin/diagnostic-test-text-art-unicode-bw.c: New test.
	* gcc.dg/plugin/diagnostic-test-text-art-unicode-color.c: New test.
	* gcc.dg/plugin/diagnostic_plugin_test_text_art.c: New test plugin.
	* gcc.dg/plugin/plugin.exp (plugin_test_list): Add them.

libcpp/ChangeLog:
	* charset.cc (get_cppchar_property): New function template, based
	on...
	(cpp_wcwidth): ...this function.  Rework to use the above.
	Include "combining-chars.inc".
	(cpp_is_combining_char): New function
	Include "printable-chars.inc".
	(cpp_is_printable_char): New function
	* combining-chars.inc: New file, generated by
	contrib/unicode/gen-combining-chars.py.
	* include/cpplib.h (cpp_is_combining_char): New function decl.
	(cpp_is_printable_char): New function decl.
	* printable-chars.inc: New file, generated by
	contrib/unicode/gen-printable-chars.py.
---
 contrib/unicode/gen-box-drawing-chars.py      |   94 ++
 contrib/unicode/gen-combining-chars.py        |   75 +
 contrib/unicode/gen-printable-chars.py        |   77 +
 gcc/Makefile.in                               |   11 +-
 gcc/color-macros.h                            |   16 +
 gcc/common.opt                                |   23 +
 gcc/configure                                 |    2 +-
 gcc/configure.ac                              |    2 +-
 gcc/diagnostic-diagram.h                      |   51 +
 gcc/diagnostic-format-json.cc                 |   10 +
 gcc/diagnostic-format-sarif.cc                |  106 +-
 gcc/diagnostic-text-art.h                     |   49 +
 gcc/diagnostic.cc                             |   72 +
 gcc/diagnostic.h                              |   21 +
 gcc/doc/invoke.texi                           |   25 +-
 gcc/gcc.cc                                    |    6 +
 gcc/opts-common.cc                            |    1 +
 gcc/opts.cc                                   |    6 +
 gcc/pretty-print.cc                           |   29 +
 gcc/pretty-print.h                            |    1 +
 gcc/selftest-run-tests.cc                     |    3 +
 .../diagnostic-test-text-art-ascii-bw.c       |   57 +
 .../diagnostic-test-text-art-ascii-color.c    |   58 +
 .../plugin/diagnostic-test-text-art-none.c    |    5 +
 .../diagnostic-test-text-art-unicode-bw.c     |   58 +
 .../diagnostic-test-text-art-unicode-color.c  |   59 +
 .../plugin/diagnostic_plugin_test_text_art.c  |  257 ++++
 gcc/testsuite/gcc.dg/plugin/plugin.exp        |    6 +
 gcc/text-art/box-drawing-chars.inc            |   18 +
 gcc/text-art/box-drawing.cc                   |   72 +
 gcc/text-art/box-drawing.h                    |   32 +
 gcc/text-art/canvas.cc                        |  437 ++++++
 gcc/text-art/canvas.h                         |   74 +
 gcc/text-art/ruler.cc                         |  723 ++++++++++
 gcc/text-art/ruler.h                          |  125 ++
 gcc/text-art/selftests.cc                     |   77 +
 gcc/text-art/selftests.h                      |   60 +
 gcc/text-art/style.cc                         |  632 ++++++++
 gcc/text-art/styled-string.cc                 | 1107 ++++++++++++++
 gcc/text-art/table.cc                         | 1272 +++++++++++++++++
 gcc/text-art/table.h                          |  262 ++++
 gcc/text-art/theme.cc                         |  183 +++
 gcc/text-art/theme.h                          |  123 ++
 gcc/text-art/types.h                          |  504 +++++++
 gcc/text-art/widget.cc                        |  275 ++++
 gcc/text-art/widget.h                         |  246 ++++
 libcpp/charset.cc                             |   89 +-
 libcpp/combining-chars.inc                    |   68 +
 libcpp/include/cpplib.h                       |    3 +
 libcpp/printable-chars.inc                    |  231 +++
 50 files changed, 7760 insertions(+), 33 deletions(-)
 create mode 100755 contrib/unicode/gen-box-drawing-chars.py
 create mode 100755 contrib/unicode/gen-combining-chars.py
 create mode 100755 contrib/unicode/gen-printable-chars.py
 create mode 100644 gcc/diagnostic-diagram.h
 create mode 100644 gcc/diagnostic-text-art.h
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-bw.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-color.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-none.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-bw.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-color.c
 create mode 100644 gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_text_art.c
 create mode 100644 gcc/text-art/box-drawing-chars.inc
 create mode 100644 gcc/text-art/box-drawing.cc
 create mode 100644 gcc/text-art/box-drawing.h
 create mode 100644 gcc/text-art/canvas.cc
 create mode 100644 gcc/text-art/canvas.h
 create mode 100644 gcc/text-art/ruler.cc
 create mode 100644 gcc/text-art/ruler.h
 create mode 100644 gcc/text-art/selftests.cc
 create mode 100644 gcc/text-art/selftests.h
 create mode 100644 gcc/text-art/style.cc
 create mode 100644 gcc/text-art/styled-string.cc
 create mode 100644 gcc/text-art/table.cc
 create mode 100644 gcc/text-art/table.h
 create mode 100644 gcc/text-art/theme.cc
 create mode 100644 gcc/text-art/theme.h
 create mode 100644 gcc/text-art/types.h
 create mode 100644 gcc/text-art/widget.cc
 create mode 100644 gcc/text-art/widget.h
 create mode 100644 libcpp/combining-chars.inc
 create mode 100644 libcpp/printable-chars.inc

diff --git a/contrib/unicode/gen-box-drawing-chars.py b/contrib/unicode/gen-box-drawing-chars.py
new file mode 100755
index 00000000000..9a55266ab84
--- /dev/null
+++ b/contrib/unicode/gen-box-drawing-chars.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+#
+# Script to generate gcc/text-art/box-drawing-chars.inc
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.  */
+
+import unicodedata
+
+def get_box_drawing_char_name(up: bool,
+                              down: bool,
+                              left: bool,
+                              right: bool) -> str:
+    if 0:
+        print(f'{locals()=}')
+    if up and down:
+        vertical = True
+        up = False
+        down = False
+    else:
+        vertical = False
+
+    if left and right:
+        horizontal = True
+        left = False
+        right = False
+    else:
+        horizontal = False
+
+    weights = []
+    heavy = []
+    light = []
+    dirs = []
+    for dir_name in ('up', 'down', 'vertical', 'left', 'right', 'horizontal'):
+        val = locals()[dir_name]
+        if val:
+            dirs.append(dir_name.upper())
+
+    if not dirs:
+        return 'SPACE'
+
+    name = 'BOX DRAWINGS'
+    #print(f'{light=} {heavy=}')
+
+    if 0:
+        print(dirs)
+
+    def weights_frag(weight: str, dirs: list, prefix: bool):
+        """
+        Generate a fragment where all directions share the same weight, e.g.:
+        'HEAVY HORIZONTAL'
+        'DOWN LIGHT'
+        'LEFT DOWN HEAVY'
+        'HEAVY DOWN AND RIGHT'
+        """
+        assert len(dirs) >= 1
+        assert len(dirs) <= 2
+        if prefix:
+            return f' {weight} ' + (' AND '.join(dirs))
+        else:
+            return ' ' + (' '.join(dirs)) + f' {weight}'
+
+    assert(len(dirs) >= 1 and len(dirs) <= 2)
+    name += weights_frag('LIGHT', dirs, True)
+
+    return name
+
+print('/* Generated by contrib/unicode/gen-box-drawing-chars.py.  */')
+print()
+for i in range(16):
+    up = (i & 8)
+    down = (i & 4)
+    left = (i & 2)
+    right = (i & 1)
+    name = get_box_drawing_char_name(up, down, left, right)
+    if i < 15:
+        trailing_comma = ','
+    else:
+        trailing_comma = ' '
+    unichar = unicodedata.lookup(name)
+    print(f'0x{ord(unichar):04X}{trailing_comma} /* "{unichar}": U+{ord(unichar):04X}: {name} */')
diff --git a/contrib/unicode/gen-combining-chars.py b/contrib/unicode/gen-combining-chars.py
new file mode 100755
index 00000000000..fb5ef50ba4c
--- /dev/null
+++ b/contrib/unicode/gen-combining-chars.py
@@ -0,0 +1,75 @@
+#!/usr/bin/env python3
+#
+# Script to generate libcpp/combining-chars.inc
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.  */
+
+from pprint import pprint
+import unicodedata
+
+def is_combining_char(code_point) -> bool:
+    return unicodedata.combining(chr(code_point)) != 0
+
+class Range:
+    def __init__(self, start, end, value):
+        self.start = start
+        self.end = end
+        self.value = value
+
+    def __repr__(self):
+        return f'Range({self.start:x}, {self.end:x}, {self.value})'
+
+def make_ranges(value_callback):
+    ranges = []
+    for code_point in range(0x10FFFF):
+        value = is_combining_char(code_point)
+        if 0:
+            print(f'{code_point=:x} {value=}')
+        if ranges and ranges[-1].value == value:
+            # Extend current range
+            ranges[-1].end = code_point
+        else:
+            # Start a new range
+            ranges.append(Range(code_point, code_point, value))
+    return ranges
+
+ranges = make_ranges(is_combining_char)
+if 0:
+    pprint(ranges)
+
+print(f"/* Generated by contrib/unicode/gen-combining-chars.py")
+print(f"   using version {unicodedata.unidata_version}"
+      " of the Unicode standard.  */")
+print("\nstatic const cppchar_t combining_range_ends[] = {", end="")
+for i, r in enumerate(ranges):
+    if i % 8:
+        print(" ", end="")
+    else:
+        print("\n  ", end="")
+    print("0x%x," % r.end, end="")
+print("\n};\n")
+print("static const bool is_combining[] = {", end="")
+for i, r in enumerate(ranges):
+    if i % 24:
+        print(" ", end="")
+    else:
+        print("\n  ", end="")
+    if r.value:
+        print("1,", end="")
+    else:
+        print("0,", end="")
+print("\n};")
diff --git a/contrib/unicode/gen-printable-chars.py b/contrib/unicode/gen-printable-chars.py
new file mode 100755
index 00000000000..7684c086638
--- /dev/null
+++ b/contrib/unicode/gen-printable-chars.py
@@ -0,0 +1,77 @@
+#!/usr/bin/env python3
+#
+# Script to generate libcpp/printable-chars.inc
+#
+# This file is part of GCC.
+#
+# GCC is free software; you can redistribute it and/or modify it under
+# the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 3, or (at your option) any later
+# version.
+#
+# GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+# WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+# for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with GCC; see the file COPYING3.  If not see
+# <http://www.gnu.org/licenses/>.  */
+
+from pprint import pprint
+import unicodedata
+
+def is_printable_char(code_point) -> bool:
+    category = unicodedata.category(chr(code_point))
+    # "Cc" is "control" and "Cf" is "format"
+    return category[0] != 'C'
+
+class Range:
+    def __init__(self, start, end, value):
+        self.start = start
+        self.end = end
+        self.value = value
+
+    def __repr__(self):
+        return f'Range({self.start:x}, {self.end:x}, {self.value})'
+
+def make_ranges(value_callback):
+    ranges = []
+    for code_point in range(0x10FFFF):
+        value = is_printable_char(code_point)
+        if 0:
+            print(f'{code_point=:x} {value=}')
+        if ranges and ranges[-1].value == value:
+            # Extend current range
+            ranges[-1].end = code_point
+        else:
+            # Start a new range
+            ranges.append(Range(code_point, code_point, value))
+    return ranges
+
+ranges = make_ranges(is_printable_char)
+if 0:
+    pprint(ranges)
+
+print(f"/* Generated by contrib/unicode/gen-printable-chars.py")
+print(f"   using version {unicodedata.unidata_version}"
+      " of the Unicode standard.  */")
+print("\nstatic const cppchar_t printable_range_ends[] = {", end="")
+for i, r in enumerate(ranges):
+    if i % 8:
+        print(" ", end="")
+    else:
+        print("\n  ", end="")
+    print("0x%x," % r.end, end="")
+print("\n};\n")
+print("static const bool is_printable[] = {", end="")
+for i, r in enumerate(ranges):
+    if i % 24:
+        print(" ", end="")
+    else:
+        print("\n  ", end="")
+    if r.value:
+        print("1,", end="")
+    else:
+        print("0,", end="")
+print("\n};")
diff --git a/gcc/Makefile.in b/gcc/Makefile.in
index 1d39e6dd3f8..c1e7257ed24 100644
--- a/gcc/Makefile.in
+++ b/gcc/Makefile.in
@@ -1781,7 +1781,16 @@ OBJS-libcommon = diagnostic-spec.o diagnostic.o diagnostic-color.o \
 	json.o \
 	sbitmap.o \
 	vec.o input.o hash-table.o ggc-none.o memory-block.o \
-	selftest.o selftest-diagnostic.o sort.o
+	selftest.o selftest-diagnostic.o sort.o \
+	text-art/box-drawing.o \
+	text-art/canvas.o \
+	text-art/ruler.o \
+	text-art/selftests.o \
+	text-art/style.o \
+	text-art/styled-string.o \
+	text-art/table.o \
+	text-art/theme.o \
+	text-art/widget.o
 
 # Objects in libcommon-target.a, used by drivers and by the core
 # compiler and containing target-dependent code.
diff --git a/gcc/color-macros.h b/gcc/color-macros.h
index fcd79d09c01..9688f92110a 100644
--- a/gcc/color-macros.h
+++ b/gcc/color-macros.h
@@ -92,6 +92,14 @@ along with GCC; see the file COPYING3.  If not see
 #define COLOR_FG_MAGENTA	"35"
 #define COLOR_FG_CYAN		"36"
 #define COLOR_FG_WHITE		"37"
+#define COLOR_FG_BRIGHT_BLACK	"90"
+#define COLOR_FG_BRIGHT_RED	"91"
+#define COLOR_FG_BRIGHT_GREEN	"92"
+#define COLOR_FG_BRIGHT_YELLOW	"93"
+#define COLOR_FG_BRIGHT_BLUE	"94"
+#define COLOR_FG_BRIGHT_MAGENTA	"95"
+#define COLOR_FG_BRIGHT_CYAN	"96"
+#define COLOR_FG_BRIGHT_WHITE	"97"
 #define COLOR_BG_BLACK		"40"
 #define COLOR_BG_RED		"41"
 #define COLOR_BG_GREEN		"42"
@@ -100,6 +108,14 @@ along with GCC; see the file COPYING3.  If not see
 #define COLOR_BG_MAGENTA	"45"
 #define COLOR_BG_CYAN		"46"
 #define COLOR_BG_WHITE		"47"
+#define COLOR_BG_BRIGHT_BLACK	"100"
+#define COLOR_BG_BRIGHT_RED	"101"
+#define COLOR_BG_BRIGHT_GREEN	"102"
+#define COLOR_BG_BRIGHT_YELLOW	"103"
+#define COLOR_BG_BRIGHT_BLUE	"104"
+#define COLOR_BG_BRIGHT_MAGENTA	"105"
+#define COLOR_BG_BRIGHT_CYAN	"106"
+#define COLOR_BG_BRIGHT_WHITE	"107"
 #define SGR_START		"\33["
 #define SGR_END			"m\33[K"
 #define SGR_SEQ(str)		SGR_START str SGR_END
diff --git a/gcc/common.opt b/gcc/common.opt
index a28ca13385a..b3c82b8607c 100644
--- a/gcc/common.opt
+++ b/gcc/common.opt
@@ -1502,6 +1502,29 @@ fdiagnostics-show-path-depths
 Common Var(flag_diagnostics_show_path_depths) Init(0)
 Show stack depths of events in paths.
 
+fdiagnostics-text-art-charset=
+Driver Common Joined RejectNegative Var(flag_diagnostics_text_art_charset) Enum(diagnostic_text_art_charset) Init(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
+-fdiagnostics-text-art-charset=[none|ascii|unicode|emoji]	Determine which characters to use in text arg diagrams.
+
+; Required for these enum values.
+SourceInclude
+diagnostic-text-art.h
+
+Enum
+Name(diagnostic_text_art_charset) Type(int)
+
+EnumValue
+Enum(diagnostic_text_art_charset) String(none) Value(DIAGNOSTICS_TEXT_ART_CHARSET_NONE)
+
+EnumValue
+Enum(diagnostic_text_art_charset) String(ascii) Value(DIAGNOSTICS_TEXT_ART_CHARSET_ASCII)
+
+EnumValue
+Enum(diagnostic_text_art_charset) String(unicode) Value(DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE)
+
+EnumValue
+Enum(diagnostic_text_art_charset) String(emoji) Value(DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI)
+
 fdiagnostics-minimum-margin-width=
 Common Joined UInteger Var(diagnostics_minimum_margin_width) Init(6)
 Set minimum width of left margin of source code when showing source.
diff --git a/gcc/configure b/gcc/configure
index 5f67808b774..e061d2b1949 100755
--- a/gcc/configure
+++ b/gcc/configure
@@ -33995,7 +33995,7 @@ $as_echo "$as_me: executing $ac_file commands" >&6;}
     "depdir":C) $SHELL $ac_aux_dir/mkinstalldirs $DEPDIR ;;
     "gccdepdir":C)
   ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
-  for lang in $subdirs c-family common analyzer rtl-ssa
+  for lang in $subdirs c-family common analyzer text-art rtl-ssa
   do
       ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
   done ;;
diff --git a/gcc/configure.ac b/gcc/configure.ac
index cc8dd9e20bf..350d245c89f 100644
--- a/gcc/configure.ac
+++ b/gcc/configure.ac
@@ -1384,7 +1384,7 @@ AC_CHECK_HEADERS(ext/hash_map)
 ZW_CREATE_DEPDIR
 AC_CONFIG_COMMANDS([gccdepdir],[
   ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
-  for lang in $subdirs c-family common analyzer rtl-ssa
+  for lang in $subdirs c-family common analyzer text-art rtl-ssa
   do
       ${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
   done], [subdirs="$subdirs" ac_aux_dir=$ac_aux_dir DEPDIR=$DEPDIR])
diff --git a/gcc/diagnostic-diagram.h b/gcc/diagnostic-diagram.h
new file mode 100644
index 00000000000..fc923c512ed
--- /dev/null
+++ b/gcc/diagnostic-diagram.h
@@ -0,0 +1,51 @@
+/* Support for diagrams within diagnostics.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_DIAGNOSTIC_DIAGRAM_H
+#define GCC_DIAGNOSTIC_DIAGRAM_H
+
+namespace text_art
+{
+  class canvas;
+} // namespace text_art
+
+/* A text art diagram, along with an "alternative text" string
+   describing it.  */
+
+class diagnostic_diagram
+{
+ public:
+  diagnostic_diagram (const text_art::canvas &canvas,
+		      const char *alt_text)
+  : m_canvas (canvas),
+    m_alt_text (alt_text)
+  {
+    gcc_assert (alt_text);
+  }
+
+  const text_art::canvas &get_canvas () const { return m_canvas; }
+  const char *get_alt_text () const { return m_alt_text; }
+
+ private:
+  const text_art::canvas &m_canvas;
+  const char *const m_alt_text;
+};
+
+#endif /* ! GCC_DIAGNOSTIC_DIAGRAM_H */
diff --git a/gcc/diagnostic-format-json.cc b/gcc/diagnostic-format-json.cc
index 694dddca9e8..539b98b5e74 100644
--- a/gcc/diagnostic-format-json.cc
+++ b/gcc/diagnostic-format-json.cc
@@ -324,6 +324,15 @@ json_file_final_cb (diagnostic_context *)
   free (filename);
 }
 
+/* Callback for diagnostic_context::m_diagrams.m_emission_cb.  */
+
+static void
+json_emit_diagram (diagnostic_context *,
+		   const diagnostic_diagram &)
+{
+  /* No-op.  */
+}
+
 /* Populate CONTEXT in preparation for JSON output (either to stderr, or
    to a file).  */
 
@@ -340,6 +349,7 @@ diagnostic_output_format_init_json (diagnostic_context *context)
   context->begin_group_cb = json_begin_group;
   context->end_group_cb =  json_end_group;
   context->print_path = NULL; /* handled in json_end_diagnostic.  */
+  context->m_diagrams.m_emission_cb = json_emit_diagram;
 
   /* The metadata is handled in JSON format, rather than as text.  */
   context->show_cwe = false;
diff --git a/gcc/diagnostic-format-sarif.cc b/gcc/diagnostic-format-sarif.cc
index fd29ac2ca3b..ac2f5b844e3 100644
--- a/gcc/diagnostic-format-sarif.cc
+++ b/gcc/diagnostic-format-sarif.cc
@@ -29,6 +29,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "cpplib.h"
 #include "logical-location.h"
 #include "diagnostic-client-data-hooks.h"
+#include "diagnostic-diagram.h"
+#include "text-art/canvas.h"
 
 class sarif_builder;
 
@@ -66,8 +68,13 @@ public:
 			diagnostic_info *diagnostic,
 			diagnostic_t orig_diag_kind,
 			sarif_builder *builder);
+  void on_diagram (diagnostic_context *context,
+		   const diagnostic_diagram &diagram,
+		   sarif_builder *builder);
 
 private:
+  void add_related_location (json::object *location_obj);
+
   json::array *m_related_locations_arr;
 };
 
@@ -135,7 +142,8 @@ public:
 
   void end_diagnostic (diagnostic_context *context, diagnostic_info *diagnostic,
 		       diagnostic_t orig_diag_kind);
-
+  void emit_diagram (diagnostic_context *context,
+		     const diagnostic_diagram &diagram);
   void end_group ();
 
   void flush_to_file (FILE *outf);
@@ -144,6 +152,9 @@ public:
   json::object *make_location_object (const rich_location &rich_loc,
 				      const logical_location *logical_loc);
   json::object *make_message_object (const char *msg) const;
+  json::object *
+  make_message_object_for_diagram (diagnostic_context *context,
+				   const diagnostic_diagram &diagram);
 
 private:
   sarif_result *make_result_object (diagnostic_context *context,
@@ -261,12 +272,6 @@ sarif_result::on_nested_diagnostic (diagnostic_context *context,
 				    diagnostic_t /*orig_diag_kind*/,
 				    sarif_builder *builder)
 {
-  if (!m_related_locations_arr)
-    {
-      m_related_locations_arr = new json::array ();
-      set ("relatedLocations", m_related_locations_arr);
-    }
-
   /* We don't yet generate meaningful logical locations for notes;
      sometimes these will related to current_function_decl, but
      often they won't.  */
@@ -277,6 +282,39 @@ sarif_result::on_nested_diagnostic (diagnostic_context *context,
   pp_clear_output_area (context->printer);
   location_obj->set ("message", message_obj);
 
+  add_related_location (location_obj);
+}
+
+/* Handle diagrams that occur within a diagnostic group.
+   The closest thing in SARIF seems to be to add a location to the
+   "releatedLocations" property  (SARIF v2.1.0 section 3.27.22),
+   and to put the diagram into the "message" property of that location
+   (SARIF v2.1.0 section 3.28.5).  */
+
+void
+sarif_result::on_diagram (diagnostic_context *context,
+			  const diagnostic_diagram &diagram,
+			  sarif_builder *builder)
+{
+  json::object *location_obj = new json::object ();
+  json::object *message_obj
+    = builder->make_message_object_for_diagram (context, diagram);
+  location_obj->set ("message", message_obj);
+
+  add_related_location (location_obj);
+}
+
+/* Add LOCATION_OBJ to this result's "relatedLocations" array,
+   creating it if it doesn't yet exist.  */
+
+void
+sarif_result::add_related_location (json::object *location_obj)
+{
+  if (!m_related_locations_arr)
+    {
+      m_related_locations_arr = new json::array ();
+      set ("relatedLocations", m_related_locations_arr);
+    }
   m_related_locations_arr->append (location_obj);
 }
 
@@ -348,6 +386,18 @@ sarif_builder::end_diagnostic (diagnostic_context *context,
     }
 }
 
+/* Implementation of diagnostic_context::m_diagrams.m_emission_cb
+   for SARIF output.  */
+
+void
+sarif_builder::emit_diagram (diagnostic_context *context,
+			     const diagnostic_diagram &diagram)
+{
+  /* We must be within the emission of a top-level diagnostic.  */
+  gcc_assert (m_cur_group_result);
+  m_cur_group_result->on_diagram (context, diagram, this);
+}
+
 /* Implementation of "end_group_cb" for SARIF output.  */
 
 void
@@ -1115,6 +1165,37 @@ sarif_builder::make_message_object (const char *msg) const
   return message_obj;
 }
 
+/* Make a message object (SARIF v2.1.0 section 3.11) for DIAGRAM.
+   We emit the diagram as a code block within the Markdown part
+   of the message.  */
+
+json::object *
+sarif_builder::make_message_object_for_diagram (diagnostic_context *context,
+						const diagnostic_diagram &diagram)
+{
+  json::object *message_obj = new json::object ();
+
+  /* "text" property (SARIF v2.1.0 section 3.11.8).  */
+  message_obj->set ("text", new json::string (diagram.get_alt_text ()));
+
+  char *saved_prefix = pp_take_prefix (context->printer);
+  pp_set_prefix (context->printer, NULL);
+
+  /* "To produce a code block in Markdown, simply indent every line of
+     the block by at least 4 spaces or 1 tab."
+     Here we use 4 spaces.  */
+  diagram.get_canvas ().print_to_pp (context->printer, "    ");
+  pp_set_prefix (context->printer, saved_prefix);
+
+  /* "markdown" property (SARIF v2.1.0 section 3.11.9).  */
+  message_obj->set ("markdown",
+		    new json::string (pp_formatted_text (context->printer)));
+
+  pp_clear_output_area (context->printer);
+
+  return message_obj;
+}
+
 /* Make a multiformatMessageString object (SARIF v2.1.0 section 3.12)
    for MSG.  */
 
@@ -1630,6 +1711,16 @@ sarif_ice_handler (diagnostic_context *context)
   fnotice (stderr, "Internal compiler error:\n");
 }
 
+/* Callback for diagnostic_context::m_diagrams.m_emission_cb.  */
+
+static void
+sarif_emit_diagram (diagnostic_context *context,
+		    const diagnostic_diagram &diagram)
+{
+  gcc_assert (the_builder);
+  the_builder->emit_diagram (context, diagram);
+}
+
 /* Populate CONTEXT in preparation for SARIF output (either to stderr, or
    to a file).  */
 
@@ -1645,6 +1736,7 @@ diagnostic_output_format_init_sarif (diagnostic_context *context)
   context->end_group_cb =  sarif_end_group;
   context->print_path = NULL; /* handled in sarif_end_diagnostic.  */
   context->ice_handler_cb = sarif_ice_handler;
+  context->m_diagrams.m_emission_cb = sarif_emit_diagram;
 
   /* The metadata is handled in SARIF format, rather than as text.  */
   context->show_cwe = false;
diff --git a/gcc/diagnostic-text-art.h b/gcc/diagnostic-text-art.h
new file mode 100644
index 00000000000..a0d8a78f52a
--- /dev/null
+++ b/gcc/diagnostic-text-art.h
@@ -0,0 +1,49 @@
+/* Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_DIAGNOSTIC_TEXT_ART_H
+#define GCC_DIAGNOSTIC_TEXT_ART_H
+
+/* Values for -fdiagnostics-text-art-charset=.  */
+
+enum diagnostic_text_art_charset
+{
+  /* No text art diagrams shall be emitted.  */
+  DIAGNOSTICS_TEXT_ART_CHARSET_NONE,
+
+  /* Use pure ASCII for text art diagrams.  */
+  DIAGNOSTICS_TEXT_ART_CHARSET_ASCII,
+
+  /* Use ASCII + conservative use of other unicode characters
+     in text art diagrams.  */
+  DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE,
+
+  /* Use Emoji.  */
+  DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI
+};
+
+const enum diagnostic_text_art_charset DIAGNOSTICS_TEXT_ART_CHARSET_DEFAULT
+  = DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI;
+
+extern void
+diagnostics_text_art_charset_init (diagnostic_context *context,
+				  enum diagnostic_text_art_charset charset);
+
+
+#endif /* ! GCC_DIAGNOSTIC_TEXT_ART_H */
diff --git a/gcc/diagnostic.cc b/gcc/diagnostic.cc
index 0f093081161..7c2289f0634 100644
--- a/gcc/diagnostic.cc
+++ b/gcc/diagnostic.cc
@@ -35,11 +35,14 @@ along with GCC; see the file COPYING3.  If not see
 #include "diagnostic-metadata.h"
 #include "diagnostic-path.h"
 #include "diagnostic-client-data-hooks.h"
+#include "diagnostic-text-art.h"
+#include "diagnostic-diagram.h"
 #include "edit-context.h"
 #include "selftest.h"
 #include "selftest-diagnostic.h"
 #include "opts.h"
 #include "cpplib.h"
+#include "text-art/theme.h"
 
 #ifdef HAVE_TERMIOS_H
 # include <termios.h>
@@ -244,6 +247,10 @@ diagnostic_initialize (diagnostic_context *context, int n_opts)
   context->ice_handler_cb = NULL;
   context->includes_seen = NULL;
   context->m_client_data_hooks = NULL;
+  context->m_diagrams.m_theme = NULL;
+  context->m_diagrams.m_emission_cb = NULL;
+  diagnostics_text_art_charset_init (context,
+				     DIAGNOSTICS_TEXT_ART_CHARSET_DEFAULT);
 }
 
 /* Maybe initialize the color support. We require clients to do this
@@ -320,6 +327,12 @@ diagnostic_finish (diagnostic_context *context)
   if (context->final_cb)
     context->final_cb (context);
 
+  if (context->m_diagrams.m_theme)
+    {
+      delete context->m_diagrams.m_theme;
+      context->m_diagrams.m_theme = NULL;
+    }
+
   diagnostic_file_cache_fini ();
 
   XDELETEVEC (context->classify_diagnostic);
@@ -2174,6 +2187,33 @@ internal_error_no_backtrace (const char *gmsgid, ...)
 
   gcc_unreachable ();
 }
+
+/* Emit DIAGRAM to CONTEXT, respecting the output format.  */
+
+void
+diagnostic_emit_diagram (diagnostic_context *context,
+			 const diagnostic_diagram &diagram)
+{
+  if (context->m_diagrams.m_theme == nullptr)
+    return;
+
+  if (context->m_diagrams.m_emission_cb)
+    {
+      context->m_diagrams.m_emission_cb (context, diagram);
+      return;
+    }
+
+  /* Default implementation.  */
+  char *saved_prefix = pp_take_prefix (context->printer);
+  pp_set_prefix (context->printer, NULL);
+  /* Use a newline before and after and a two-space indent
+     to make the diagram stand out a little from the wall of text.  */
+  pp_newline (context->printer);
+  diagram.get_canvas ().print_to_pp (context->printer, "  ");
+  pp_newline (context->printer);
+  pp_set_prefix (context->printer, saved_prefix);
+  pp_flush (context->printer);
+}
 \f
 /* Special case error functions.  Most are implemented in terms of the
    above, or should be.  */
@@ -2316,6 +2356,38 @@ diagnostic_output_format_init (diagnostic_context *context,
     }
 }
 
+/* Initialize CONTEXT->m_diagrams based on CHARSET.
+   Specifically, make a text_art::theme object for m_diagrams.m_theme,
+   (or NULL for "no diagrams").  */
+
+void
+diagnostics_text_art_charset_init (diagnostic_context *context,
+				   enum diagnostic_text_art_charset charset)
+{
+  delete context->m_diagrams.m_theme;
+  switch (charset)
+    {
+    default:
+      gcc_unreachable ();
+
+    case DIAGNOSTICS_TEXT_ART_CHARSET_NONE:
+      context->m_diagrams.m_theme = NULL;
+      break;
+
+    case DIAGNOSTICS_TEXT_ART_CHARSET_ASCII:
+      context->m_diagrams.m_theme = new text_art::ascii_theme ();
+      break;
+
+    case DIAGNOSTICS_TEXT_ART_CHARSET_UNICODE:
+      context->m_diagrams.m_theme = new text_art::unicode_theme ();
+      break;
+
+    case DIAGNOSTICS_TEXT_ART_CHARSET_EMOJI:
+      context->m_diagrams.m_theme = new text_art::emoji_theme ();
+      break;
+    }
+}
+
 /* Implementation of diagnostic_path::num_events vfunc for
    simple_diagnostic_path: simply get the number of events in the vec.  */
 
diff --git a/gcc/diagnostic.h b/gcc/diagnostic.h
index 9a51097f146..00b828f230d 100644
--- a/gcc/diagnostic.h
+++ b/gcc/diagnostic.h
@@ -24,6 +24,11 @@ along with GCC; see the file COPYING3.  If not see
 #include "pretty-print.h"
 #include "diagnostic-core.h"
 
+namespace text_art
+{
+  class theme;
+} // namespace text_art
+
 /* An enum for controlling what units to use for the column number
    when diagnostics are output, used by the -fdiagnostics-column-unit option.
    Tabs will be expanded or not according to the value of -ftabstop.  The origin
@@ -170,6 +175,7 @@ class edit_context;
 namespace json { class value; }
 class diagnostic_client_data_hooks;
 class logical_location;
+class diagnostic_diagram;
 
 /* This data structure bundles altogether any information relevant to
    the context of a diagnostic message.  */
@@ -417,6 +423,18 @@ struct diagnostic_context
      Used by SARIF output to give metadata about the client that's
      producing diagnostics.  */
   diagnostic_client_data_hooks *m_client_data_hooks;
+
+  /* Support for diagrams.  */
+  struct
+  {
+    /* Theme to use when generating diagrams.
+       Can be NULL (if text art is disabled).  */
+    text_art::theme *m_theme;
+
+    /* Callback for emitting diagrams.  */
+    void (*m_emission_cb) (diagnostic_context *context,
+			   const diagnostic_diagram &diagram);
+  } m_diagrams;
 };
 
 inline void
@@ -619,4 +637,7 @@ extern bool warning_enabled_at (location_t, int);
 
 extern char *get_cwe_url (int cwe);
 
+extern void diagnostic_emit_diagram (diagnostic_context *context,
+				     const diagnostic_diagram &diagram);
+
 #endif /* ! GCC_DIAGNOSTIC_H */
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 898a88ce33e..023a56a647e 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -316,7 +316,8 @@ Objective-C and Objective-C++ Dialects}.
 -fno-show-column
 -fdiagnostics-column-unit=@r{[}display@r{|}byte@r{]}
 -fdiagnostics-column-origin=@var{origin}
--fdiagnostics-escape-format=@r{[}unicode@r{|}bytes@r{]}}
+-fdiagnostics-escape-format=@r{[}unicode@r{|}bytes@r{]}
+-fdiagnostics-text-art-charset=@r{[}none@r{|}ascii@r{|}unicode@r{|}emoji@r{]}}
 
 @item Warning Options
 @xref{Warning Options,,Options to Request or Suppress Warnings}.
@@ -5066,7 +5067,8 @@ options:
 -fno-diagnostics-show-line-numbers
 -fdiagnostics-color=never
 -fdiagnostics-urls=never
--fdiagnostics-path-format=separate-events}
+-fdiagnostics-path-format=separate-events
+-fdiagnostics-text-art-charset=none}
 In the future, if GCC changes the default appearance of its diagnostics, the
 corresponding option to disable the new behavior will be added to this list.
 
@@ -5592,6 +5594,25 @@ Unicode characters.  For the example above, the following will be printed:
  before<CF><80><BF>after
 @end smallexample
 
+@opindex fdiagnostics-text-art-charset
+@item -fdiagnostics-text-art-charset=@var{CHARSET}
+Some diagnostics can contain ``text art'' diagrams: visualizations created
+from text, intended to be viewed in a monospaced font.
+
+This option selects which characters should be used for printing such
+diagrams, if any.  @var{CHARSET} is @samp{none}, @samp{ascii}, @samp{unicode},
+or @samp{emoji}.
+
+The @samp{none} value suppresses the printing of such diagrams.
+The @samp{ascii} value will ensure that such diagrams are pure ASCII
+(``ASCII art'').  The @samp{unicode} value will allow for conservative use of
+unicode drawing characters (such as box-drawing characters).  The @samp{emoji}
+value further adds the possibility of emoji in the output (such as emitting
+U+26A0 WARNING SIGN followed by U+FE0F VARIATION SELECTOR-16 to select the
+emoji variant of the character).
+
+The default is @samp{emoji}.
+
 @opindex fdiagnostics-format
 @item -fdiagnostics-format=@var{FORMAT}
 Select a different format for printing diagnostics.
diff --git a/gcc/gcc.cc b/gcc/gcc.cc
index 2ccca00d603..f9f0a7eaad4 100644
--- a/gcc/gcc.cc
+++ b/gcc/gcc.cc
@@ -46,6 +46,7 @@ compilation is specified by a string called a "spec".  */
 #include "spellcheck.h"
 #include "opts-jobserver.h"
 #include "common/common-target.h"
+#include "diagnostic-text-art.h"
 
 \f
 
@@ -4299,6 +4300,11 @@ driver_handle_option (struct gcc_options *opts,
 	  break;
 	}
 
+    case OPT_fdiagnostics_text_art_charset_:
+      diagnostics_text_art_charset_init (dc,
+					 (enum diagnostic_text_art_charset)value);
+      break;
+
     case OPT_Wa_:
       {
 	int prev, j;
diff --git a/gcc/opts-common.cc b/gcc/opts-common.cc
index 23ddcaa3b55..f0c5f483665 100644
--- a/gcc/opts-common.cc
+++ b/gcc/opts-common.cc
@@ -1068,6 +1068,7 @@ decode_cmdline_options_to_array (unsigned int argc, const char **argv,
 	    "-fdiagnostics-color=never",
 	    "-fdiagnostics-urls=never",
 	    "-fdiagnostics-path-format=separate-events",
+	    "-fdiagnostics-text-art-charset=none"
 	  };
 	  const int num_expanded = ARRAY_SIZE (expanded_args);
 	  opt_array_len += num_expanded - 1;
diff --git a/gcc/opts.cc b/gcc/opts.cc
index 86b94d62b58..3087bdac2c6 100644
--- a/gcc/opts.cc
+++ b/gcc/opts.cc
@@ -35,6 +35,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "version.h"
 #include "selftest.h"
 #include "file-prefix-map.h"
+#include "diagnostic-text-art.h"
 
 /* In this file all option sets are explicit.  */
 #undef OPTION_SET_P
@@ -2887,6 +2888,11 @@ common_handle_option (struct gcc_options *opts,
 	  break;
 	}
 
+    case OPT_fdiagnostics_text_art_charset_:
+      diagnostics_text_art_charset_init (dc,
+					 (enum diagnostic_text_art_charset)value);
+      break;
+
     case OPT_fdiagnostics_parseable_fixits:
       dc->extra_output_kind = (value
 			       ? EXTRA_DIAGNOSTIC_OUTPUT_fixits_v1
diff --git a/gcc/pretty-print.cc b/gcc/pretty-print.cc
index 7d294717f50..3d789a23812 100644
--- a/gcc/pretty-print.cc
+++ b/gcc/pretty-print.cc
@@ -1828,6 +1828,35 @@ pp_string (pretty_printer *pp, const char *str)
   pp_maybe_wrap_text (pp, str, str + strlen (str));
 }
 
+/* Append code point C to the output area of PRETTY-PRINTER, encoding it
+   as UTF-8.  */
+
+void
+pp_unicode_character (pretty_printer *pp, unsigned c)
+{
+  static const uchar masks[6] =  { 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
+  static const uchar limits[6] = { 0x80, 0xE0, 0xF0, 0xF8, 0xFC, 0xFE };
+  size_t nbytes;
+  uchar buf[6], *p = &buf[6];
+
+  nbytes = 1;
+  if (c < 0x80)
+    *--p = c;
+  else
+    {
+      do
+	{
+	  *--p = ((c & 0x3F) | 0x80);
+	  c >>= 6;
+	  nbytes++;
+	}
+      while (c >= 0x3F || (c & limits[nbytes-1]));
+      *--p = (c | masks[nbytes-1]);
+    }
+
+  pp_append_r (pp, (const char *)p, nbytes);
+}
+
 /* Append the leading N characters of STRING to the output area of
    PRETTY-PRINTER, quoting in hexadecimal non-printable characters.
    Setting N = -1 is as if N were set to strlen (STRING).  The STRING
diff --git a/gcc/pretty-print.h b/gcc/pretty-print.h
index 0230a289df5..369be6e7ba7 100644
--- a/gcc/pretty-print.h
+++ b/gcc/pretty-print.h
@@ -401,6 +401,7 @@ extern void pp_indent (pretty_printer *);
 extern void pp_newline (pretty_printer *);
 extern void pp_character (pretty_printer *, int);
 extern void pp_string (pretty_printer *, const char *);
+extern void pp_unicode_character (pretty_printer *, unsigned);
 
 extern void pp_write_text_to_stream (pretty_printer *);
 extern void pp_write_text_as_dot_label_to_stream (pretty_printer *, bool);
diff --git a/gcc/selftest-run-tests.cc b/gcc/selftest-run-tests.cc
index 915f2129702..e2fc8f84b1b 100644
--- a/gcc/selftest-run-tests.cc
+++ b/gcc/selftest-run-tests.cc
@@ -28,6 +28,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "stringpool.h"
 #include "attribs.h"
 #include "analyzer/analyzer-selftests.h"
+#include "text-art/selftests.h"
 
 /* This function needed to be split out from selftest.cc as it references
    tests from the whole source tree, and so is within
@@ -118,6 +119,8 @@ selftest::run_tests ()
   /* Run any lang-specific selftests.  */
   lang_hooks.run_lang_selftests ();
 
+  text_art_tests ();
+
   /* Run the analyzer selftests (if enabled).  */
   ana::selftest::run_analyzer_selftests ();
 
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-bw.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-bw.c
new file mode 100644
index 00000000000..e4239aab032
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-bw.c
@@ -0,0 +1,57 @@
+/* { dg-additional-options "-fdiagnostics-text-art-charset=ascii -fdiagnostics-color=never" } */
+
+int non_empty;
+
+/* { dg-begin-multiline-output "" }
+
+  A
+   B
+    C
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ♜ ♞ ♝ ♛ ♚ ♝ ♞ ♜
+  ♟ ♟ ♟ ♟ ♟ ♟ ♟ ♟
+  
+  
+  
+  
+  ♙ ♙ ♙ ♙ ♙ ♙ ♙ ♙
+  ♖ ♘ ♗ ♕ ♔ ♗ ♘ ♖
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  +--+
+  |🙂|
+  +--+
+
+   { dg-end-multiline-output "" } */
+/* { dg-begin-multiline-output "" }
+
+  +-------+-----+---------------+---------------------+-----------------------+-----------------------+
+  |Offsets|Octet|       0       |          1          |           2           |           3           |
+  +-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+  | Octet | Bit |0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27|28|29|30|31|
+  +-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+  |   0   |  0  |Version|  IHL  |     DSCP      | ECN |                 Total Length                  |
+  +-------+-----+-------+-------+---------------+-----+--------+--------------------------------------+
+  |   4   | 32  |           Identification            | Flags  |           Fragment Offset            |
+  +-------+-----+---------------+---------------------+--------+--------------------------------------+
+  |   8   | 64  | Time To Live  |      Protocol       |                Header Checksum                |
+  +-------+-----+---------------+---------------------+-----------------------------------------------+
+  |  12   | 96  |                                  Source IP Address                                  |
+  +-------+-----+-------------------------------------------------------------------------------------+
+  |  16   | 128 |                               Destination IP Address                                |
+  +-------+-----+-------------------------------------------------------------------------------------+
+  |  20   | 160 |                                                                                     |
+  +-------+-----+                                                                                     |
+  |  ...  | ... |                                       Options                                       |
+  +-------+-----+                                                                                     |
+  |  56   | 448 |                                                                                     |
+  +-------+-----+-------------------------------------------------------------------------------------+
+
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-color.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-color.c
new file mode 100644
index 00000000000..0650428b1ce
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-ascii-color.c
@@ -0,0 +1,58 @@
+/* { dg-additional-options "-fdiagnostics-text-art-charset=ascii -fdiagnostics-color=always" } */
+
+int non_empty;
+
+/* { dg-begin-multiline-output "" }
+
+  A
+   B
+    C
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ^[[38;2;0;0;0;48;2;240;217;181m^[[K♜ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♞ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♝ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♛ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♚ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♝ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♞ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♜ ^[[m^[[K
+  ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[m^[[K
+  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[m^[[K
+  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[m^[[K
+  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[m^[[K
+  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[m^[[K
+  ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[m^[[K
+  ^[[38;2;255;255;255;48;2;181;136;99m^[[K♖ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♘ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♗ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♕ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♔ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♗ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♘ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♖ ^[[m^[[K
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  +--+
+  |🙂|
+  +--+
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  +-------+-----+---------------+---------------------+-----------------------+-----------------------+
+  |Offsets|Octet|       0       |          1          |           2           |           3           |
+  +-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+  | Octet | Bit |0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27|28|29|30|31|
+  +-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+  |   0   |  0  |Version|  IHL  |     DSCP      | ECN |                 Total Length                  |
+  +-------+-----+-------+-------+---------------+-----+--------+--------------------------------------+
+  |   4   | 32  |           Identification            | Flags  |           Fragment Offset            |
+  +-------+-----+---------------+---------------------+--------+--------------------------------------+
+  |   8   | 64  | Time To Live  |      Protocol       |                Header Checksum                |
+  +-------+-----+---------------+---------------------+-----------------------------------------------+
+  |  12   | 96  |                                  Source IP Address                                  |
+  +-------+-----+-------------------------------------------------------------------------------------+
+  |  16   | 128 |                               Destination IP Address                                |
+  +-------+-----+-------------------------------------------------------------------------------------+
+  |  20   | 160 |                                                                                     |
+  +-------+-----+                                                                                     |
+  |  ...  | ... |                                       Options                                       |
+  +-------+-----+                                                                                     |
+  |  56   | 448 |                                                                                     |
+  +-------+-----+-------------------------------------------------------------------------------------+
+
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-none.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-none.c
new file mode 100644
index 00000000000..c8118b46759
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-none.c
@@ -0,0 +1,5 @@
+/* { dg-additional-options "-fdiagnostics-text-art-charset=none" } */
+
+int non_empty;
+
+/* We expect no output.  */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-bw.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-bw.c
new file mode 100644
index 00000000000..c9f5b36571a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-bw.c
@@ -0,0 +1,58 @@
+/* { dg-additional-options "-fdiagnostics-text-art-charset=unicode -fdiagnostics-color=never" } */
+
+int non_empty;
+
+/* { dg-begin-multiline-output "" }
+
+  A
+   B
+    C
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ♜ ♞ ♝ ♛ ♚ ♝ ♞ ♜
+  ♟ ♟ ♟ ♟ ♟ ♟ ♟ ♟
+  
+  
+  
+  
+  ♙ ♙ ♙ ♙ ♙ ♙ ♙ ♙
+  ♖ ♘ ♗ ♕ ♔ ♗ ♘ ♖
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ┌──┐
+  │🙂│
+  └──┘
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ┌───────┬─────┬───────────────┬─────────────────────┬───────────────────────┬───────────────────────┐
+  │Offsets│Octet│       0       │          1          │           2           │           3           │
+  ├───────┼─────┼─┬─┬─┬─┬─┬─┬─┬─┼─┬─┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┤
+  │ Octet │ Bit │0│1│2│3│4│5│6│7│8│9│10│11│12│13│14│15│16│17│18│19│20│21│22│23│24│25│26│27│28│29│30│31│
+  ├───────┼─────┼─┴─┴─┴─┼─┴─┴─┴─┼─┴─┴──┴──┴──┴──┼──┴──┼──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┤
+  │   0   │  0  │Version│  IHL  │     DSCP      │ ECN │                 Total Length                  │
+  ├───────┼─────┼───────┴───────┴───────────────┴─────┼────────┬──────────────────────────────────────┤
+  │   4   │ 32  │           Identification            │ Flags  │           Fragment Offset            │
+  ├───────┼─────┼───────────────┬─────────────────────┼────────┴──────────────────────────────────────┤
+  │   8   │ 64  │ Time To Live  │      Protocol       │                Header Checksum                │
+  ├───────┼─────┼───────────────┴─────────────────────┴───────────────────────────────────────────────┤
+  │  12   │ 96  │                                  Source IP Address                                  │
+  ├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤
+  │  16   │ 128 │                               Destination IP Address                                │
+  ├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤
+  │  20   │ 160 │                                                                                     │
+  ├───────┼─────┤                                                                                     │
+  │  ...  │ ... │                                       Options                                       │
+  ├───────┼─────┤                                                                                     │
+  │  56   │ 448 │                                                                                     │
+  └───────┴─────┴─────────────────────────────────────────────────────────────────────────────────────┘
+
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-color.c b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-color.c
new file mode 100644
index 00000000000..f402836f889
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic-test-text-art-unicode-color.c
@@ -0,0 +1,59 @@
+/* { dg-additional-options "-fdiagnostics-text-art-charset=unicode -fdiagnostics-color=always" } */
+
+int non_empty;
+
+
+/* { dg-begin-multiline-output "" }
+
+  A
+   B
+    C
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ^[[38;2;0;0;0;48;2;240;217;181m^[[K♜ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♞ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♝ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♛ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♚ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♝ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♞ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♜ ^[[m^[[K
+  ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[38;2;0;0;0;48;2;181;136;99m^[[K♟ ^[[38;2;0;0;0;48;2;240;217;181m^[[K♟ ^[[m^[[K
+  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[m^[[K
+  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[m^[[K
+  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[m^[[K
+  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[48;2;181;136;99m^[[K  ^[[48;2;240;217;181m^[[K  ^[[m^[[K
+  ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♙ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♙ ^[[m^[[K
+  ^[[38;2;255;255;255;48;2;181;136;99m^[[K♖ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♘ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♗ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♕ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♔ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♗ ^[[38;2;255;255;255;48;2;181;136;99m^[[K♘ ^[[38;2;255;255;255;48;2;240;217;181m^[[K♖ ^[[m^[[K
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ┌──┐
+  │🙂│
+  └──┘
+
+   { dg-end-multiline-output "" } */
+
+/* { dg-begin-multiline-output "" }
+
+  ┌───────┬─────┬───────────────┬─────────────────────┬───────────────────────┬───────────────────────┐
+  │Offsets│Octet│       0       │          1          │           2           │           3           │
+  ├───────┼─────┼─┬─┬─┬─┬─┬─┬─┬─┼─┬─┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┤
+  │ Octet │ Bit │0│1│2│3│4│5│6│7│8│9│10│11│12│13│14│15│16│17│18│19│20│21│22│23│24│25│26│27│28│29│30│31│
+  ├───────┼─────┼─┴─┴─┴─┼─┴─┴─┴─┼─┴─┴──┴──┴──┴──┼──┴──┼──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┤
+  │   0   │  0  │Version│  IHL  │     DSCP      │ ECN │                 Total Length                  │
+  ├───────┼─────┼───────┴───────┴───────────────┴─────┼────────┬──────────────────────────────────────┤
+  │   4   │ 32  │           Identification            │ Flags  │           Fragment Offset            │
+  ├───────┼─────┼───────────────┬─────────────────────┼────────┴──────────────────────────────────────┤
+  │   8   │ 64  │ Time To Live  │      Protocol       │                Header Checksum                │
+  ├───────┼─────┼───────────────┴─────────────────────┴───────────────────────────────────────────────┤
+  │  12   │ 96  │                                  Source IP Address                                  │
+  ├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤
+  │  16   │ 128 │                               Destination IP Address                                │
+  ├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤
+  │  20   │ 160 │                                                                                     │
+  ├───────┼─────┤                                                                                     │
+  │  ...  │ ... │                                       Options                                       │
+  ├───────┼─────┤                                                                                     │
+  │  56   │ 448 │                                                                                     │
+  └───────┴─────┴─────────────────────────────────────────────────────────────────────────────────────┘
+
+   { dg-end-multiline-output "" } */
diff --git a/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_text_art.c b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_text_art.c
new file mode 100644
index 00000000000..27c341b9f2f
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/plugin/diagnostic_plugin_test_text_art.c
@@ -0,0 +1,257 @@
+/* { dg-options "-O" } */
+
+/* This plugin exercises the text_art code.  */
+
+#include "gcc-plugin.h"
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "plugin-version.h"
+#include "diagnostic.h"
+#include "diagnostic-diagram.h"
+#include "text-art/canvas.h"
+#include "text-art/table.h"
+
+int plugin_is_GPL_compatible;
+
+using namespace text_art;
+
+/* Canvas tests.  */
+
+static void
+emit_canvas (const canvas &c, const char *alt_text)
+{
+  diagnostic_diagram diagram (c, alt_text);
+  diagnostic_emit_diagram (global_dc, diagram);
+}
+
+static void
+test_abc ()
+{
+  style_manager sm;
+  canvas c (canvas::size_t (3, 3), sm);
+  c.paint (canvas::coord_t (0, 0), styled_unichar ('A'));
+  c.paint (canvas::coord_t (1, 1), styled_unichar ('B'));
+  c.paint (canvas::coord_t (2, 2), styled_unichar ('C'));
+  emit_canvas (c, "test_abc");
+}
+
+/* Test of procedural art using 24-bit color: chess starting position.  */
+
+static void
+test_chessboard ()
+{
+  /* With the exception of NONE, these are in order of the chess symbols
+     in the Unicode Miscellaneous Symbols block.  */
+  enum class piece { KING, QUEEN, ROOK, BISHOP, KNIGHT, PAWN, NONE };
+  enum class color { BLACK, WHITE, NONE };
+
+  style_manager sm;
+
+  /* We assume double-column chars for the pieces, so allow two canvas
+     columns per square.  */
+  canvas canvas (canvas::size_t (16, 8), sm);
+
+  for (int x = 0; x < 8; x++)
+    for (int y = 0; y < 8; y++)
+      {
+	enum piece piece_kind;
+	enum color piece_color;
+	switch (y)
+	  {
+	  case 0:
+	  case 7:
+	    switch (x)
+	      {
+	      default:
+		gcc_unreachable ();
+	      case 0:
+		piece_kind = piece::ROOK;
+		break;
+	      case 1:
+		piece_kind = piece::KNIGHT;
+		break;
+	      case 2:
+		piece_kind = piece::BISHOP;
+		break;
+	      case 3:
+		piece_kind = piece::QUEEN;
+		break;
+	      case 4:
+		piece_kind = piece::KING;
+		break;
+	      case 5:
+		piece_kind = piece::BISHOP;
+		break;
+	      case 6:
+		piece_kind = piece::KNIGHT;
+		break;
+	      case 7:
+		piece_kind = piece::ROOK;
+	      break;
+	      }
+	    piece_color = (y == 0) ? color::BLACK : color::WHITE;
+	    break;
+	  case 1:
+	  case 6:
+	    piece_kind = piece::PAWN;
+	    piece_color = (y == 1) ? color::BLACK : color::WHITE;
+	    break;
+	  default:
+	    piece_kind = piece::NONE;
+	    piece_color = color::NONE;
+	    break;
+	  }
+
+	style s;
+	const bool white_square = (x + y) % 2 == 0;
+	if (white_square)
+	  s.m_bg_color = style::color (0xf0, 0xd9, 0xb5);
+	else
+	  s.m_bg_color = style::color (0xb5, 0x88, 0x63);
+	switch (piece_color)
+	  {
+	  default:
+	    gcc_unreachable ();
+	  case color::WHITE:
+	    s.m_fg_color = style::color (0xff, 0xff, 0xff);
+	    break;
+	  case color::BLACK:
+	    s.m_fg_color = style::color (0x00, 0x00, 0x00);
+	    break;
+	  case color::NONE:
+	    break;
+	  }
+	style::id_t style_id = sm.get_or_create_id (s);
+
+	cppchar_t ch;
+	if (piece_kind == piece::NONE)
+	  ch = ' ';
+	else
+	  {
+	    const cppchar_t WHITE_KING = 0x2654;
+	    const cppchar_t BLACK_KING = 0x265A;
+	    cppchar_t base ((piece_color == color::WHITE)
+			    ? WHITE_KING : BLACK_KING);
+	    ch = base + ((int)piece_kind - (int)piece::KING);
+	  }
+	canvas.paint (canvas::coord_t (x * 2, y),
+		      canvas::cell_t (ch, false, style_id));
+	canvas.paint (canvas::coord_t (x * 2 + 1, y),
+		      canvas::cell_t (' ', false, style_id));
+      }
+  emit_canvas (canvas, "test_chessboard");
+}
+
+/* Table tests.  */
+
+static void
+emit_table (const table &table, const style_manager &sm, const char *alt_text)
+{
+  const text_art::theme *theme = global_dc->m_diagrams.m_theme;
+  if (!theme)
+    return;
+  canvas c (table.to_canvas (*theme, sm));
+  emit_canvas (c, alt_text);
+}
+
+static void
+test_double_width_chars ()
+{
+  style_manager sm;
+  table table (table::size_t (1, 1));
+  table.set_cell (table::coord_t (0,0),
+		  styled_string ((cppchar_t)0x1f642));
+
+  emit_table (table, sm, "test_double_width_chars");
+}
+
+static void
+test_ipv4_header ()
+{
+  style_manager sm;
+  table table (table::size_t (34, 10));
+  table.set_cell (table::coord_t (0, 0), styled_string (sm, "Offsets"));
+  table.set_cell (table::coord_t (1, 0), styled_string (sm, "Octet"));
+  table.set_cell (table::coord_t (0, 1), styled_string (sm, "Octet"));
+  for (int octet = 0; octet < 4; octet++)
+    table.set_cell_span (table::rect_t (table::coord_t (2 + (octet * 8), 0),
+					table::size_t (8, 1)),
+			 styled_string::from_fmt (sm, nullptr, "%i", octet));
+  table.set_cell (table::coord_t (1, 1), styled_string (sm, "Bit"));
+  for (int bit = 0; bit < 32; bit++)
+    table.set_cell (table::coord_t (bit + 2, 1),
+		    styled_string::from_fmt (sm, nullptr, "%i", bit));
+  for (int word = 0; word < 6; word++)
+    {
+      table.set_cell (table::coord_t (0, word + 2),
+		      styled_string::from_fmt (sm, nullptr, "%i", word * 4));
+      table.set_cell (table::coord_t (1, word + 2),
+		      styled_string::from_fmt (sm, nullptr, "%i", word * 32));
+    }
+
+  table.set_cell (table::coord_t (0, 8), styled_string (sm, "..."));
+  table.set_cell (table::coord_t (1, 8), styled_string (sm, "..."));
+  table.set_cell (table::coord_t (0, 9), styled_string (sm, "56"));
+  table.set_cell (table::coord_t (1, 9), styled_string (sm, "448"));
+
+#define SET_BITS(FIRST, LAST, NAME)					\
+  do {									\
+    const int first = (FIRST);						\
+    const int last = (LAST);						\
+    const char *name = (NAME);						\
+    const int row = first / 32;						\
+    gcc_assert (last / 32 == row);					\
+    table::rect_t rect (table::coord_t ((first % 32) + 2, row + 2),	\
+			table::size_t (last + 1 - first , 1));		\
+    table.set_cell_span (rect, styled_string (sm, name));		\
+  } while (0)
+
+  SET_BITS (0, 3, "Version");
+  SET_BITS (4, 7, "IHL");
+  SET_BITS (8, 13, "DSCP");
+  SET_BITS (14, 15, "ECN");
+  SET_BITS (16, 31, "Total Length");
+
+  SET_BITS (32 +  0, 32 + 15, "Identification");
+  SET_BITS (32 + 16, 32 + 18, "Flags");
+  SET_BITS (32 + 19, 32 + 31, "Fragment Offset");
+
+  SET_BITS (64 +  0, 64 +  7, "Time To Live");
+  SET_BITS (64 +  8, 64 + 15, "Protocol");
+  SET_BITS (64 + 16, 64 + 31, "Header Checksum");
+
+  SET_BITS (96 +  0, 96 + 31, "Source IP Address");
+  SET_BITS (128 +  0, 128 + 31, "Destination IP Address");
+
+  table.set_cell_span(table::rect_t (table::coord_t (2, 7),
+				     table::size_t (32, 3)),
+		      styled_string (sm, "Options"));
+
+  emit_table (table, sm, "test_ipv4_header");
+}
+
+static void
+show_diagrams ()
+{
+  test_abc ();
+  test_chessboard ();
+  test_double_width_chars ();
+  test_ipv4_header ();
+}
+
+int
+plugin_init (struct plugin_name_args *plugin_info,
+	     struct plugin_gcc_version *version)
+{
+  const char *plugin_name = plugin_info->base_name;
+  int argc = plugin_info->argc;
+  struct plugin_argument *argv = plugin_info->argv;
+
+  if (!plugin_default_version_check (version, &gcc_version))
+    return 1;
+
+  show_diagrams ();
+
+  return 0;
+}
diff --git a/gcc/testsuite/gcc.dg/plugin/plugin.exp b/gcc/testsuite/gcc.dg/plugin/plugin.exp
index 4d6304cd100..60723a20eda 100644
--- a/gcc/testsuite/gcc.dg/plugin/plugin.exp
+++ b/gcc/testsuite/gcc.dg/plugin/plugin.exp
@@ -114,6 +114,12 @@ set plugin_test_list [list \
 	  diagnostic-path-format-inline-events-1.c \
 	  diagnostic-path-format-inline-events-2.c \
 	  diagnostic-path-format-inline-events-3.c } \
+    { diagnostic_plugin_test_text_art.c \
+	  diagnostic-test-text-art-none.c \
+	  diagnostic-test-text-art-ascii-bw.c \
+	  diagnostic-test-text-art-ascii-color.c \
+	  diagnostic-test-text-art-unicode-bw.c \
+	  diagnostic-test-text-art-unicode-color.c } \
     { location_overflow_plugin.c \
 	  location-overflow-test-1.c \
 	  location-overflow-test-2.c \
diff --git a/gcc/text-art/box-drawing-chars.inc b/gcc/text-art/box-drawing-chars.inc
new file mode 100644
index 00000000000..a370255d56d
--- /dev/null
+++ b/gcc/text-art/box-drawing-chars.inc
@@ -0,0 +1,18 @@
+/* Generated by contrib/unicode/gen-box-drawing-chars.py.  */
+
+0x0020, /* " ": U+0020: SPACE */
+0x2576, /* "╶": U+2576: BOX DRAWINGS LIGHT RIGHT */
+0x2574, /* "╴": U+2574: BOX DRAWINGS LIGHT LEFT */
+0x2500, /* "─": U+2500: BOX DRAWINGS LIGHT HORIZONTAL */
+0x2577, /* "╷": U+2577: BOX DRAWINGS LIGHT DOWN */
+0x250C, /* "┌": U+250C: BOX DRAWINGS LIGHT DOWN AND RIGHT */
+0x2510, /* "┐": U+2510: BOX DRAWINGS LIGHT DOWN AND LEFT */
+0x252C, /* "┬": U+252C: BOX DRAWINGS LIGHT DOWN AND HORIZONTAL */
+0x2575, /* "╵": U+2575: BOX DRAWINGS LIGHT UP */
+0x2514, /* "└": U+2514: BOX DRAWINGS LIGHT UP AND RIGHT */
+0x2518, /* "┘": U+2518: BOX DRAWINGS LIGHT UP AND LEFT */
+0x2534, /* "┴": U+2534: BOX DRAWINGS LIGHT UP AND HORIZONTAL */
+0x2502, /* "│": U+2502: BOX DRAWINGS LIGHT VERTICAL */
+0x251C, /* "├": U+251C: BOX DRAWINGS LIGHT VERTICAL AND RIGHT */
+0x2524, /* "┤": U+2524: BOX DRAWINGS LIGHT VERTICAL AND LEFT */
+0x253C  /* "┼": U+253C: BOX DRAWINGS LIGHT VERTICAL AND HORIZONTAL */
diff --git a/gcc/text-art/box-drawing.cc b/gcc/text-art/box-drawing.cc
new file mode 100644
index 00000000000..981d0b095cf
--- /dev/null
+++ b/gcc/text-art/box-drawing.cc
@@ -0,0 +1,72 @@
+/* Procedural lookup of box drawing characters.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "text-art/box-drawing.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+
+
+/* According to
+     https://en.wikipedia.org/wiki/Box-drawing_character#Character_code
+   "DOS line- and box-drawing characters are not ordered in any programmatic
+   manner, so calculating a particular character shape needs to use a look-up
+   table. "
+   Hence this array.  */
+static const cppchar_t box_drawing_chars[] = {
+#include "text-art/box-drawing-chars.inc"
+};
+
+cppchar_t
+text_art::get_box_drawing_char (directions line_dirs)
+{
+  const size_t idx = line_dirs.as_index ();
+  gcc_assert (idx < 16);
+  return box_drawing_chars[idx];
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Run all selftests in this file.  */
+
+void
+text_art_box_drawing_cc_tests ()
+{
+  ASSERT_EQ (text_art::get_box_drawing_char
+	      (text_art::directions (false, false, false, false)),
+	     ' ');
+  ASSERT_EQ (text_art::get_box_drawing_char
+	       (text_art::directions (false, false, true, true)),
+	     0x2500); /* BOX DRAWINGS LIGHT HORIZONTAL */
+  ASSERT_EQ (text_art::get_box_drawing_char
+	       (text_art::directions (true, true, false, false)),
+	     0x2502); /* BOX DRAWINGS LIGHT VERTICAL */
+  ASSERT_EQ (text_art::get_box_drawing_char
+	       (text_art::directions (true, false, true, false)),
+	     0x2518); /* BOX DRAWINGS LIGHT UP AND LEFT */
+}
+
+} // namespace selftest
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/box-drawing.h b/gcc/text-art/box-drawing.h
new file mode 100644
index 00000000000..29f4d9921b3
--- /dev/null
+++ b/gcc/text-art/box-drawing.h
@@ -0,0 +1,32 @@
+/* Procedural lookup of box drawing characters.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_BOX_DRAWING_H
+#define GCC_TEXT_ART_BOX_DRAWING_H
+
+#include "text-art/types.h"
+
+namespace text_art {
+
+extern cppchar_t get_box_drawing_char (directions line_dirs);
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_BOX_DRAWING_H */
diff --git a/gcc/text-art/canvas.cc b/gcc/text-art/canvas.cc
new file mode 100644
index 00000000000..f229612c919
--- /dev/null
+++ b/gcc/text-art/canvas.cc
@@ -0,0 +1,437 @@
+/* Canvas for random-access procedural text art.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "pretty-print.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/canvas.h"
+
+using namespace text_art;
+
+canvas::canvas (size_t size, const style_manager &style_mgr)
+: m_cells (size_t (size.w, size.h)),
+  m_style_mgr (style_mgr)
+{
+  m_cells.fill (cell_t (' '));
+}
+
+void
+canvas::paint (coord_t coord, styled_unichar ch)
+{
+  m_cells.set (coord, std::move (ch));
+}
+
+void
+canvas::paint_text (coord_t coord, const styled_string &text)
+{
+  for (auto ch : text)
+    {
+      paint (coord, ch);
+      if (ch.double_width_p ())
+	coord.x += 2;
+      else
+	coord.x++;
+    }
+}
+
+void
+canvas::fill (rect_t rect, cell_t c)
+{
+  for (int y = rect.get_min_y (); y < rect.get_next_y (); y++)
+    for (int x = rect.get_min_x (); x < rect.get_next_x (); x++)
+      paint(coord_t (x, y), c);
+}
+
+void
+canvas::debug_fill ()
+{
+  fill (rect_t (coord_t (0, 0), get_size ()), cell_t ('*'));
+}
+
+void
+canvas::print_to_pp (pretty_printer *pp,
+		     const char *per_line_prefix) const
+{
+  for (int y = 0; y < m_cells.get_size ().h; y++)
+    {
+      style::id_t curr_style_id = 0;
+      if (per_line_prefix)
+	pp_string (pp, per_line_prefix);
+
+      pretty_printer line_pp;
+      line_pp.show_color = pp->show_color;
+      line_pp.url_format = pp->url_format;
+      const int final_x_in_row = get_final_x_in_row (y);
+      for (int x = 0; x <= final_x_in_row; x++)
+	{
+	  if (x > 0)
+	    {
+	      const cell_t prev_cell = m_cells.get (coord_t (x - 1, y));
+	      if (prev_cell.double_width_p ())
+		 /* This cell is just a placeholder for the
+		    2nd column of a double width cell; skip it.  */
+		continue;
+	    }
+	  const cell_t cell = m_cells.get (coord_t (x, y));
+	  if (cell.get_style_id () != curr_style_id)
+	    {
+	      m_style_mgr.print_any_style_changes (&line_pp,
+						   curr_style_id,
+						   cell.get_style_id ());
+	      curr_style_id = cell.get_style_id ();
+	    }
+	  pp_unicode_character (&line_pp, cell.get_code ());
+	  if (cell.emoji_variant_p ())
+	    /* Append U+FE0F VARIATION SELECTOR-16 to select the emoji
+	       variation of the char.  */
+	    pp_unicode_character (&line_pp, 0xFE0F);
+	}
+      /* Reset the style at the end of each line.  */
+      m_style_mgr.print_any_style_changes (&line_pp, curr_style_id, 0);
+
+      /* Print from line_pp to pp, stripping trailing whitespace from
+	 the line.  */
+      const char *line_buf = pp_formatted_text (&line_pp);
+      ::size_t len = strlen (line_buf);
+      while (len > 0)
+	{
+	  if (line_buf[len - 1] == ' ')
+	    len--;
+	  else
+	    break;
+	}
+      pp_append_text (pp, line_buf, line_buf + len);
+      pp_newline (pp);
+    }
+}
+
+DEBUG_FUNCTION void
+canvas::debug (bool styled) const
+{
+  pretty_printer pp;
+  if (styled)
+    {
+      pp_show_color (&pp) = true;
+      pp.url_format = determine_url_format (DIAGNOSTICS_URL_AUTO);
+    }
+  print_to_pp (&pp);
+  fprintf (stderr, "%s\n", pp_formatted_text (&pp));
+}
+
+/* Find right-most non-default cell in this row,
+   or -1 if all are default.  */
+
+int
+canvas::get_final_x_in_row (int y) const
+{
+  for (int x = m_cells.get_size ().w - 1; x >= 0; x--)
+    {
+      cell_t cell = m_cells.get (coord_t (x, y));
+      if (cell.get_code () != ' '
+	  || cell.get_style_id () != style::id_plain)
+	return x;
+    }
+  return -1;
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+static void
+test_blank ()
+{
+  style_manager sm;
+  canvas c (canvas::size_t (5, 5), sm);
+  ASSERT_CANVAS_STREQ (c, false,
+		       ("\n"
+			"\n"
+			"\n"
+			"\n"
+			"\n"));
+}
+
+static void
+test_abc ()
+{
+  style_manager sm;
+  canvas c (canvas::size_t (3, 3), sm);
+  c.paint (canvas::coord_t (0, 0), styled_unichar ('A'));
+  c.paint (canvas::coord_t (1, 1), styled_unichar ('B'));
+  c.paint (canvas::coord_t (2, 2), styled_unichar ('C'));
+
+  ASSERT_CANVAS_STREQ (c, false,
+		       "A\n B\n  C\n");
+}
+
+static void
+test_debug_fill ()
+{
+  style_manager sm;
+  canvas c (canvas::size_t (5, 3), sm);
+  c.debug_fill();
+  ASSERT_CANVAS_STREQ (c, false,
+		       ("*****\n"
+			"*****\n"
+			"*****\n"));
+}
+
+static void
+test_text ()
+{
+  style_manager sm;
+  canvas c (canvas::size_t (6, 1), sm);
+  c.paint_text (canvas::coord_t (0, 0), styled_string (sm, "012345"));
+  ASSERT_CANVAS_STREQ (c, false,
+		       ("012345\n"));
+
+  /* Paint an emoji character that should occupy two canvas columns when
+     printed.  */
+  c.paint_text (canvas::coord_t (2, 0), styled_string ((cppchar_t)0x1f642));
+  ASSERT_CANVAS_STREQ (c, false,
+		       ("01🙂45\n"));
+}
+
+static void
+test_circle ()
+{
+  canvas::size_t sz (30, 30);
+  style_manager sm;
+  canvas canvas (sz, sm);
+  canvas::coord_t center (sz.w / 2, sz.h / 2);
+  const int radius = 12;
+  const int radius_squared = radius * radius;
+  for (int x = 0; x < sz.w; x++)
+    for (int y = 0; y < sz.h; y++)
+      {
+	int dx = x - center.x;
+	int dy = y - center.y;
+	char ch = "AB"[(x + y) % 2];
+	if (dx * dx + dy * dy < radius_squared)
+	  canvas.paint (canvas::coord_t (x, y), styled_unichar (ch));
+      }
+  ASSERT_CANVAS_STREQ
+    (canvas, false,
+     ("\n"
+      "\n"
+      "\n"
+      "\n"
+      "           BABABABAB\n"
+      "         ABABABABABABA\n"
+      "        ABABABABABABABA\n"
+      "       ABABABABABABABABA\n"
+      "      ABABABABABABABABABA\n"
+      "     ABABABABABABABABABABA\n"
+      "     BABABABABABABABABABAB\n"
+      "    BABABABABABABABABABABAB\n"
+      "    ABABABABABABABABABABABA\n"
+      "    BABABABABABABABABABABAB\n"
+      "    ABABABABABABABABABABABA\n"
+      "    BABABABABABABABABABABAB\n"
+      "    ABABABABABABABABABABABA\n"
+      "    BABABABABABABABABABABAB\n"
+      "    ABABABABABABABABABABABA\n"
+      "    BABABABABABABABABABABAB\n"
+      "     BABABABABABABABABABAB\n"
+      "     ABABABABABABABABABABA\n"
+      "      ABABABABABABABABABA\n"
+      "       ABABABABABABABABA\n"
+      "        ABABABABABABABA\n"
+      "         ABABABABABABA\n"
+      "           BABABABAB\n"
+      "\n"
+      "\n"
+      "\n"));
+}
+
+static void
+test_color_circle ()
+{
+  const canvas::size_t sz (10, 10);
+  const canvas::coord_t center (sz.w / 2, sz.h / 2);
+  const int outer_r2 = 25;
+  const int inner_r2 = 10;
+  style_manager sm;
+  canvas c (sz, sm);
+  for (int x = 0; x < sz.w; x++)
+    for (int y = 0; y < sz.h; y++)
+      {
+	const int dist_from_center_squared
+	  = ((x - center.x) * (x - center.x) + (y - center.y) * (y - center.y));
+	if (dist_from_center_squared < outer_r2)
+	  {
+	    style s;
+	    if (dist_from_center_squared < inner_r2)
+	      s.m_fg_color = style::named_color::RED;
+	    else
+	      s.m_fg_color = style::named_color::GREEN;
+	    c.paint (canvas::coord_t (x, y),
+		     styled_unichar ('*', false, sm.get_or_create_id (s)));
+	  }
+      }
+  ASSERT_EQ (sm.get_num_styles (), 3);
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("\n"
+      "   *****\n"
+      "  *******\n"
+      " *********\n"
+      " *********\n"
+      " *********\n"
+      " *********\n"
+      " *********\n"
+      "  *******\n"
+      "   *****\n"));
+  ASSERT_CANVAS_STREQ
+    (c, true,
+     ("\n"
+      "   ^[[32m^[[K*****^[[m^[[K\n"
+      "  ^[[32m^[[K***^[[31m^[[K*^[[32m^[[K***^[[m^[[K\n"
+      " ^[[32m^[[K**^[[31m^[[K*****^[[32m^[[K**^[[m^[[K\n"
+      " ^[[32m^[[K**^[[31m^[[K*****^[[32m^[[K**^[[m^[[K\n"
+      " ^[[32m^[[K*^[[31m^[[K*******^[[32m^[[K*^[[m^[[K\n"
+      " ^[[32m^[[K**^[[31m^[[K*****^[[32m^[[K**^[[m^[[K\n"
+      " ^[[32m^[[K**^[[31m^[[K*****^[[32m^[[K**^[[m^[[K\n"
+      "  ^[[32m^[[K***^[[31m^[[K*^[[32m^[[K***^[[m^[[K\n"
+      "   ^[[32m^[[K*****^[[m^[[K\n"));
+}
+
+static void
+test_bold ()
+{
+  auto_fix_quotes fix_quotes;
+  style_manager sm;
+  styled_string s (styled_string::from_fmt (sm, nullptr,
+					    "before %qs after", "foo"));
+  canvas c (canvas::size_t (s.calc_canvas_width (), 1), sm);
+  c.paint_text (canvas::coord_t (0, 0), s);
+  ASSERT_CANVAS_STREQ (c, false,
+		       "before `foo' after\n");
+  ASSERT_CANVAS_STREQ (c, true,
+		       "before `^[[00;01m^[[Kfoo^[[00m^[[K' after\n");
+}
+
+static void
+test_emoji ()
+{
+  style_manager sm;
+  styled_string s (0x26A0, /* U+26A0 WARNING SIGN.  */
+		   true);
+  canvas c (canvas::size_t (s.calc_canvas_width (), 1), sm);
+  c.paint_text (canvas::coord_t (0, 0), s);
+  ASSERT_CANVAS_STREQ (c, false, "⚠️\n");
+  ASSERT_CANVAS_STREQ (c, true, "⚠️\n");
+}
+
+static void
+test_emoji_2 ()
+{
+  style_manager sm;
+  styled_string s;
+  s.append (styled_string (0x26A0, /* U+26A0 WARNING SIGN.  */
+			   true));
+  s.append (styled_string (sm, "test"));
+  ASSERT_EQ (s.size (), 5);
+  ASSERT_EQ (s.calc_canvas_width (), 5);
+  canvas c (canvas::size_t (s.calc_canvas_width (), 1), sm);
+  c.paint_text (canvas::coord_t (0, 0), s);
+  ASSERT_CANVAS_STREQ (c, false,
+		       /* U+26A0 WARNING SIGN, as UTF-8: 0xE2 0x9A 0xA0.  */
+		       "\xE2\x9A\xA0"
+		       /* U+FE0F VARIATION SELECTOR-16, as UTF-8: 0xEF 0xB8 0x8F.  */
+		       "\xEF\xB8\x8F"
+		       "test\n");
+}
+
+static void
+test_canvas_urls ()
+{
+  style_manager sm;
+  canvas canvas (canvas::size_t (9, 3), sm);
+  styled_string foo_ss (sm, "foo");
+  foo_ss.set_url (sm, "https://www.example.com/foo");
+  styled_string bar_ss (sm, "bar");
+  bar_ss.set_url (sm, "https://www.example.com/bar");
+  canvas.paint_text(canvas::coord_t (1, 1), foo_ss);
+  canvas.paint_text(canvas::coord_t (5, 1), bar_ss);
+
+  ASSERT_CANVAS_STREQ (canvas, false,
+		       ("\n"
+			" foo bar\n"
+			"\n"));
+  {
+    pretty_printer pp;
+    pp_show_color (&pp) = true;
+    pp.url_format = URL_FORMAT_ST;
+    assert_canvas_streq (SELFTEST_LOCATION, canvas, &pp,
+			 (/* Line 1.  */
+			  "\n"
+			  /* Line 2.  */
+			  " "
+			  "\33]8;;https://www.example.com/foo\33\\foo\33]8;;\33\\"
+			  " "
+			  "\33]8;;https://www.example.com/bar\33\\bar\33]8;;\33\\"
+			  "\n"
+			  /* Line 3.  */
+			  "\n"));
+  }
+
+  {
+    pretty_printer pp;
+    pp_show_color (&pp) = true;
+    pp.url_format = URL_FORMAT_BEL;
+    assert_canvas_streq (SELFTEST_LOCATION, canvas, &pp,
+			 (/* Line 1.  */
+			  "\n"
+			  /* Line 2.  */
+			  " "
+			  "\33]8;;https://www.example.com/foo\afoo\33]8;;\a"
+			  " "
+			  "\33]8;;https://www.example.com/bar\abar\33]8;;\a"
+			  "\n"
+			  /* Line 3.  */
+			  "\n"));
+  }
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_canvas_cc_tests ()
+{
+  test_blank ();
+  test_abc ();
+  test_debug_fill ();
+  test_text ();
+  test_circle ();
+  test_color_circle ();
+  test_bold ();
+  test_emoji ();
+  test_emoji_2 ();
+  test_canvas_urls ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/canvas.h b/gcc/text-art/canvas.h
new file mode 100644
index 00000000000..495497754f5
--- /dev/null
+++ b/gcc/text-art/canvas.h
@@ -0,0 +1,74 @@
+/* Canvas for random-access procedural text art.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_CANVAS_H
+#define GCC_TEXT_ART_CANVAS_H
+
+#include "text-art/types.h"
+
+namespace text_art {
+
+class canvas;
+
+/* A 2 dimensional grid of text cells (a "canvas"), which
+   can be written to ("painted") via random access, and then
+   written out to a pretty_printer once the picture is complete.
+
+   Each text cell can be styled independently (colorization,
+   URLs, etc).  */
+
+class canvas
+{
+ public:
+  typedef styled_unichar cell_t;
+  typedef size<class canvas> size_t;
+  typedef coord<class canvas> coord_t;
+  typedef range<class canvas> range_t;
+  typedef rect<class canvas> rect_t;
+
+  canvas (size_t size, const style_manager &style_mgr);
+
+  size_t get_size () const { return m_cells.get_size (); }
+
+  void paint (coord_t coord, cell_t c);
+  void paint_text (coord_t coord, const styled_string &text);
+
+  void fill (rect_t rect, cell_t c);
+  void debug_fill ();
+
+  void print_to_pp (pretty_printer *pp,
+		    const char *per_line_prefix = NULL) const;
+  void debug (bool styled) const;
+
+  const cell_t &get (coord_t coord) const
+  {
+    return m_cells.get (coord);
+  }
+
+ private:
+  int get_final_x_in_row (int y) const;
+
+  array2<cell_t, size_t, coord_t> m_cells;
+  const style_manager &m_style_mgr;
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_CANVAS_H */
diff --git a/gcc/text-art/ruler.cc b/gcc/text-art/ruler.cc
new file mode 100644
index 00000000000..80c623f77ba
--- /dev/null
+++ b/gcc/text-art/ruler.cc
@@ -0,0 +1,723 @@
+/* Classes for printing labelled rulers.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_ALGORITHM
+#include "system.h"
+#include "coretypes.h"
+#include "pretty-print.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/ruler.h"
+#include "text-art/theme.h"
+
+using namespace text_art;
+
+void
+x_ruler::add_label (const canvas::range_t &r,
+		    styled_string text,
+		    style::id_t style_id,
+		    label_kind kind)
+{
+  m_labels.push_back (label (r, std::move (text), style_id, kind));
+  m_has_layout = false;
+}
+
+int
+x_ruler::get_canvas_y (int rel_y) const
+{
+  gcc_assert (rel_y >= 0);
+  gcc_assert (rel_y < m_size.h);
+  switch (m_label_dir)
+    {
+    default:
+      gcc_unreachable ();
+    case label_dir::ABOVE:
+      return m_size.h - (rel_y + 1);
+    case label_dir::BELOW:
+      return rel_y;
+    }
+}
+
+void
+x_ruler::paint_to_canvas (canvas &canvas,
+			  canvas::coord_t offset,
+			  const theme &theme)
+{
+  ensure_layout ();
+
+  if (0)
+    canvas.fill (canvas::rect_t (offset, m_size),
+		 canvas::cell_t ('*'));
+
+  for (size_t idx = 0; idx < m_labels.size (); idx++)
+    {
+      const label &iter_label = m_labels[idx];
+
+      /* Paint the ruler itself.  */
+      const int ruler_rel_y = get_canvas_y (0);
+      for (int rel_x = iter_label.m_range.start;
+	   rel_x < iter_label.m_range.next;
+	   rel_x++)
+	{
+	  enum theme::cell_kind kind = theme::cell_kind::X_RULER_MIDDLE;
+
+	  if (rel_x == iter_label.m_range.start)
+	    {
+	      kind = theme::cell_kind::X_RULER_LEFT_EDGE;
+	      if (idx > 0)
+		{
+		  const label &prev_label = m_labels[idx - 1];
+		  if (prev_label.m_range.get_max () == iter_label.m_range.start)
+		    kind = theme::cell_kind::X_RULER_INTERNAL_EDGE;
+		}
+	    }
+	  else if (rel_x == iter_label.m_range.get_max ())
+	    kind = theme::cell_kind::X_RULER_RIGHT_EDGE;
+	  else if (rel_x == iter_label.m_connector_x)
+	    {
+	      switch (m_label_dir)
+		{
+		default:
+		  gcc_unreachable ();
+		case label_dir::ABOVE:
+		  kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE;
+		  break;
+		case label_dir::BELOW:
+		  kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW;
+		  break;
+		}
+	    }
+	  canvas.paint (canvas::coord_t (rel_x, ruler_rel_y) + offset,
+			theme.get_cell (kind, iter_label.m_style_id));
+	}
+
+      /* Paint the connector to the text.  */
+      for (int connector_rel_y = 1;
+	   connector_rel_y < iter_label.m_text_rect.get_min_y ();
+	   connector_rel_y++)
+	{
+	  canvas.paint
+	    ((canvas::coord_t (iter_label.m_connector_x,
+			       get_canvas_y (connector_rel_y))
+	      + offset),
+	     theme.get_cell (theme::cell_kind::X_RULER_VERTICAL_CONNECTOR,
+			     iter_label.m_style_id));
+	}
+
+      /* Paint the text.  */
+      switch (iter_label.m_kind)
+	{
+	default:
+	  gcc_unreachable ();
+	case x_ruler::label_kind::TEXT:
+	  canvas.paint_text
+	    ((canvas::coord_t (iter_label.m_text_rect.get_min_x (),
+			       get_canvas_y (iter_label.m_text_rect.get_min_y ()))
+	      + offset),
+	     iter_label.m_text);
+	  break;
+
+	case x_ruler::label_kind::TEXT_WITH_BORDER:
+	  {
+	    const canvas::range_t rel_x_range
+	      (iter_label.m_text_rect.get_x_range ());
+
+	    enum theme::cell_kind inner_left_kind;
+	    enum theme::cell_kind inner_connector_kind;
+	    enum theme::cell_kind inner_right_kind;
+	    enum theme::cell_kind outer_left_kind;
+	    enum theme::cell_kind outer_right_kind;
+
+	      switch (m_label_dir)
+		{
+		default:
+		  gcc_unreachable ();
+		case label_dir::ABOVE:
+		  outer_left_kind = theme::cell_kind::TEXT_BORDER_TOP_LEFT;
+		  outer_right_kind = theme::cell_kind::TEXT_BORDER_TOP_RIGHT;
+		  inner_left_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_LEFT;
+		  inner_connector_kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW;
+		  inner_right_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_RIGHT;
+		  break;
+		case label_dir::BELOW:
+		  inner_left_kind = theme::cell_kind::TEXT_BORDER_TOP_LEFT;
+		  inner_connector_kind = theme::cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE;
+		  inner_right_kind = theme::cell_kind::TEXT_BORDER_TOP_RIGHT;
+		  outer_left_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_LEFT;
+		  outer_right_kind = theme::cell_kind::TEXT_BORDER_BOTTOM_RIGHT;
+		  break;
+		}
+	    /* Inner border.  */
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_min_y ());
+	      /* Left corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (inner_left_kind,
+					    iter_label.m_style_id));
+	      /* Edge.  */
+	      const canvas::cell_t edge_border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_HORIZONTAL,
+				  iter_label.m_style_id);
+	      const canvas::cell_t connector_border_cell
+		= theme.get_cell (inner_connector_kind,
+				  iter_label.m_style_id);
+	      for (int rel_x = rel_x_range.get_min () + 1;
+		   rel_x < rel_x_range.get_max ();
+		   rel_x++)
+		if (rel_x == iter_label.m_connector_x)
+		  canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+				 + offset),
+				connector_border_cell);
+		else
+		  canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+				 + offset),
+				edge_border_cell);
+
+	      /* Right corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (inner_right_kind,
+					    iter_label.m_style_id));
+	    }
+
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_min_y () + 1);
+	      const canvas::cell_t border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_VERTICAL,
+				  iter_label.m_style_id);
+
+	      /* Left border.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    border_cell);
+	      /* Text.  */
+	      canvas.paint_text ((canvas::coord_t (rel_x_range.get_min () + 1,
+						   rel_canvas_y)
+				  + offset),
+				 iter_label.m_text);
+	      /* Right border.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    border_cell);
+	    }
+
+	    /* Outer border.  */
+	    {
+	      const int rel_canvas_y
+		= get_canvas_y (iter_label.m_text_rect.get_max_y ());
+	      /* Left corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_min (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (outer_left_kind,
+					    iter_label.m_style_id));
+	      /* Edge.  */
+	      const canvas::cell_t border_cell
+		= theme.get_cell (theme::cell_kind::TEXT_BORDER_HORIZONTAL,
+				  iter_label.m_style_id);
+	      for (int rel_x = rel_x_range.get_min () + 1;
+		   rel_x < rel_x_range.get_max ();
+		   rel_x++)
+		canvas.paint ((canvas::coord_t (rel_x, rel_canvas_y)
+			       + offset),
+			      border_cell);
+
+	      /* Right corner.  */
+	      canvas.paint ((canvas::coord_t (rel_x_range.get_max (),
+					      rel_canvas_y)
+			     + offset),
+			    theme.get_cell (outer_right_kind,
+					    iter_label.m_style_id));
+	    }
+	  }
+	  break;
+	}
+    }
+}
+
+DEBUG_FUNCTION void
+x_ruler::debug (const style_manager &sm)
+{
+  canvas c (get_size (), sm);
+  paint_to_canvas (c, canvas::coord_t (0, 0), unicode_theme ());
+  c.debug (true);
+}
+
+x_ruler::label::label (const canvas::range_t &range,
+		       styled_string text,
+		       style::id_t style_id,
+		       label_kind kind)
+: m_range (range),
+  m_text (std::move (text)),
+  m_style_id (style_id),
+  m_kind (kind),
+  m_text_rect (canvas::coord_t (0, 0),
+	       canvas::size_t (m_text.calc_canvas_width (), 1)),
+  m_connector_x ((m_range.get_min () + m_range.get_max ()) / 2)
+{
+  if (kind == label_kind::TEXT_WITH_BORDER)
+    {
+      m_text_rect.m_size.w += 2;
+      m_text_rect.m_size.h += 2;
+    }
+}
+
+bool
+x_ruler::label::operator< (const label &other) const
+{
+  int cmp = m_range.start - other.m_range.start;
+  if (cmp)
+    return cmp < 0;
+  return m_range.next < other.m_range.next;
+}
+
+void
+x_ruler::ensure_layout ()
+{
+  if (m_has_layout)
+    return;
+  update_layout ();
+  m_has_layout = true;
+}
+
+void
+x_ruler::update_layout ()
+{
+  if (m_labels.empty ())
+    return;
+
+  std::sort (m_labels.begin (), m_labels.end ());
+
+  /* Place labels.  */
+  int ruler_width = m_labels.back ().m_range.get_next ();
+  int width_with_labels = ruler_width;
+
+  /* Get x coordinates of text parts of each label
+     (m_text_rect.m_top_left.x for each label).  */
+  for (size_t idx = 0; idx < m_labels.size (); idx++)
+    {
+      label &iter_label = m_labels[idx];
+      /* Attempt to center the text label.  */
+      int min_x;
+      if (idx > 0)
+	{
+	  /* ...but don't overlap with the connector to the left.  */
+	  int left_neighbor_connector_x = m_labels[idx - 1].m_connector_x;
+	  min_x = left_neighbor_connector_x + 1;
+	}
+      else
+	{
+	  /* ...or go beyond the leftmost column.  */
+	  min_x = 0;
+	}
+      int connector_x = iter_label.m_connector_x;
+      int centered_x
+	= connector_x - ((int)iter_label.m_text_rect.get_width () / 2);
+      int text_x = std::max (min_x, centered_x);
+      iter_label.m_text_rect.m_top_left.x = text_x;
+    }
+
+  /* Now walk backwards trying to place them vertically,
+     setting m_text_rect.m_top_left.y for each label,
+     consolidating the rows where possible.
+     The y cooordinates are stored with respect to label_dir::BELOW.  */
+  int label_y = 2;
+  for (int idx = m_labels.size () - 1; idx >= 0; idx--)
+    {
+      label &iter_label = m_labels[idx];
+      /* Does it fit on the same row as the text label to the right?  */
+      size_t text_len = iter_label.m_text_rect.get_width ();
+      /* Get the x-coord of immediately beyond iter_label's text.  */
+      int next_x = iter_label.m_text_rect.get_min_x () + text_len;
+      if (idx < (int)m_labels.size () - 1)
+	{
+	  if (next_x >= m_labels[idx + 1].m_text_rect.get_min_x ())
+	    {
+	      /* If not, start a new row.  */
+	      label_y += m_labels[idx + 1].m_text_rect.get_height ();
+	    }
+	}
+      iter_label.m_text_rect.m_top_left.y = label_y;
+      width_with_labels = std::max (width_with_labels, next_x);
+    }
+
+  m_size = canvas::size_t (width_with_labels,
+			   label_y + m_labels[0].m_text_rect.get_height ());
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+static void
+assert_x_ruler_streq (const location &loc,
+		      x_ruler &ruler,
+		      const theme &theme,
+		      const style_manager &sm,
+		      bool styled,
+		      const char *expected_str)
+{
+  canvas c (ruler.get_size (), sm);
+  ruler.paint_to_canvas (c, canvas::coord_t (0, 0), theme);
+  if (0)
+    c.debug (styled);
+  assert_canvas_streq (loc, c, styled, expected_str);
+}
+
+#define ASSERT_X_RULER_STREQ(RULER, THEME, SM, STYLED, EXPECTED_STR)	\
+  SELFTEST_BEGIN_STMT							\
+    assert_x_ruler_streq ((SELFTEST_LOCATION),				\
+			  (RULER),					\
+			  (THEME),					\
+			  (SM),						\
+			  (STYLED),					\
+			  (EXPECTED_STR));				\
+  SELFTEST_END_STMT
+
+static void
+test_single ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain, x_ruler::label_kind::TEXT);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~~~~+~~~~|\n"
+      "     |\n"
+      "    foo\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┤\n"
+      "     │\n"
+      "    foo\n"));
+}
+
+static void
+test_single_above ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::ABOVE);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "hello world"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("hello world\n"
+      "     |\n"
+      "|~~~~+~~~~|\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("hello world\n"
+      "     │\n"
+      "├────┴────┤\n"));
+}
+
+static void
+test_multiple_contiguous ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~~~~+~~~~|~+~~|\n"
+      "     |      |\n"
+      "    foo    bar\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "    foo    bar\n"));
+}
+
+static void
+test_multiple_contiguous_above ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::ABOVE);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("    foo    bar\n"
+      "     |      |\n"
+      "|~~~~+~~~~|~+~~|\n"));
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("    foo    bar\n"
+      "     │      │\n"
+      "├────┴────┼─┴──┤\n"));
+}
+
+static void
+test_multiple_contiguous_abutting_labels ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "12345678"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "1234678"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │   1234678\n"
+      " 12345678\n"));
+}
+
+static void
+test_multiple_contiguous_overlapping_labels ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11), styled_string (sm, "123456789"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16), styled_string (sm, "12346789"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │  12346789\n"
+      " 123456789\n"));
+}
+static void
+test_abutting_left_border ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 6),
+	       styled_string (sm, "this is a long label"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├─┬──┤\n"
+      "  │\n"
+      "this is a long label\n"));
+}
+
+static void
+test_too_long_to_consolidate_vertically ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11),
+	       styled_string (sm, "long string A"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16),
+	       styled_string (sm, "long string B"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │long string B\n"
+      "long string A\n"));
+}
+
+static void
+test_abutting_neighbor ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 11),
+	       styled_string (sm, "very long string A"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 16),
+	       styled_string (sm, "very long string B"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, unicode_theme (), sm, true,
+     ("├────┬────┼─┬──┤\n"
+      "     │      │\n"
+      "     │very long string B\n"
+      "very long string A\n"));
+}
+
+static void
+test_gaps ()
+{
+  style_manager sm;
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5),
+	       styled_string (sm, "foo"),
+	       style::id_plain);
+  r.add_label (canvas::range_t (10, 15),
+	       styled_string (sm, "bar"),
+	       style::id_plain);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("|~+~|     |~+~|\n"
+      "  |         |\n"
+      " foo       bar\n"));
+}
+
+static void
+test_styled ()
+{
+  style_manager sm;
+  style s1, s2;
+  s1.m_bold = true;
+  s1.m_fg_color = style::named_color::YELLOW;
+  s2.m_bold = true;
+  s2.m_fg_color = style::named_color::BLUE;
+  style::id_t sid1 = sm.get_or_create_id (s1);
+  style::id_t sid2 = sm.get_or_create_id (s2);
+
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5), styled_string (sm, "foo"), sid1);
+  r.add_label (canvas::range_t (10, 15), styled_string (sm, "bar"), sid2);
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     ("^[[00;01;33m^[[K|~+~|^[[00m^[[K     ^[[00;01;34m^[[K|~+~|^[[00m^[[K\n"
+      "  ^[[00;01;33m^[[K|^[[00m^[[K         ^[[00;01;34m^[[K|^[[00m^[[K\n"
+      " foo       bar\n"));
+}
+
+static void
+test_borders ()
+{
+  style_manager sm;
+  {
+    x_ruler r (x_ruler::label_dir::BELOW);
+    r.add_label (canvas::range_t (0, 5),
+		 styled_string (sm, "label 1"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    r.add_label (canvas::range_t (10, 15),
+		 styled_string (sm, "label 2"),
+		 style::id_plain);
+    r.add_label (canvas::range_t (20, 25),
+		 styled_string (sm, "label 3"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    ASSERT_X_RULER_STREQ
+      (r, ascii_theme (), sm, true,
+       "|~+~|     |~+~|     |~+~|\n"
+       "  |         |         |\n"
+       "  |      label 2  +---+---+\n"
+       "+-+-----+         |label 3|\n"
+       "|label 1|         +-------+\n"
+       "+-------+\n");
+    ASSERT_X_RULER_STREQ
+      (r, unicode_theme (), sm, true,
+       "├─┬─┤     ├─┬─┤     ├─┬─┤\n"
+       "  │         │         │\n"
+       "  │      label 2  ╭───┴───╮\n"
+       "╭─┴─────╮         │label 3│\n"
+       "│label 1│         ╰───────╯\n"
+       "╰───────╯\n");
+  }
+  {
+    x_ruler r (x_ruler::label_dir::ABOVE);
+    r.add_label (canvas::range_t (0, 5),
+		 styled_string (sm, "label 1"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    r.add_label (canvas::range_t (10, 15),
+		 styled_string (sm, "label 2"),
+		 style::id_plain);
+    r.add_label (canvas::range_t (20, 25),
+		 styled_string (sm, "label 3"),
+		 style::id_plain,
+		 x_ruler::label_kind::TEXT_WITH_BORDER);
+    ASSERT_X_RULER_STREQ
+      (r, ascii_theme (), sm, true,
+       "+-------+\n"
+       "|label 1|         +-------+\n"
+       "+-+-----+         |label 3|\n"
+       "  |      label 2  +---+---+\n"
+       "  |         |         |\n"
+       "|~+~|     |~+~|     |~+~|\n");
+    ASSERT_X_RULER_STREQ
+      (r, unicode_theme (), sm, true,
+       "╭───────╮\n"
+       "│label 1│         ╭───────╮\n"
+       "╰─┬─────╯         │label 3│\n"
+       "  │      label 2  ╰───┬───╯\n"
+       "  │         │         │\n"
+       "├─┴─┤     ├─┴─┤     ├─┴─┤\n");
+  }
+}
+
+static void
+test_emoji ()
+{
+  style_manager sm;
+
+  styled_string s;
+  s.append (styled_string (0x26A0, /* U+26A0 WARNING SIGN.  */
+			   true));
+  s.append (styled_string (sm, "  "));
+  s.append (styled_string (sm, "this is a warning"));
+
+  x_ruler r (x_ruler::label_dir::BELOW);
+  r.add_label (canvas::range_t (0, 5),
+	       std::move (s),
+	       style::id_plain,
+	       x_ruler::label_kind::TEXT_WITH_BORDER);
+
+  ASSERT_X_RULER_STREQ
+    (r, ascii_theme (), sm, true,
+     "|~+~|\n"
+     "  |\n"
+     "+-+------------------+\n"
+     "|⚠️  this is a warning|\n"
+     "+--------------------+\n");
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_ruler_cc_tests ()
+{
+  test_single ();
+  test_single_above ();
+  test_multiple_contiguous ();
+  test_multiple_contiguous_above ();
+  test_multiple_contiguous_abutting_labels ();
+  test_multiple_contiguous_overlapping_labels ();
+  test_abutting_left_border ();
+  test_too_long_to_consolidate_vertically ();
+  test_abutting_neighbor ();
+  test_gaps ();
+  test_styled ();
+  test_borders ();
+  test_emoji ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/ruler.h b/gcc/text-art/ruler.h
new file mode 100644
index 00000000000..31f53549836
--- /dev/null
+++ b/gcc/text-art/ruler.h
@@ -0,0 +1,125 @@
+/* Classes for printing labelled rulers.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_RULER_H
+#define GCC_TEXT_ART_RULER_H
+
+#include "text-art/canvas.h"
+
+namespace text_art {
+
+/* A way to annotate a series of ranges of canvas coordinates
+   with text labels either above or, in this example, below:
+     ├───────┬───────┼───────┬───────┼───────┬───────┤
+             │               │               │
+           label A         label B          label C
+   with logic to ensure that the text labels don't overlap
+   when printed.  */
+
+class x_ruler
+{
+ public:
+  enum class label_dir { ABOVE, BELOW };
+  enum class label_kind
+  {
+    TEXT,
+    TEXT_WITH_BORDER
+  };
+
+  x_ruler (label_dir dir)
+  : m_label_dir (dir),
+    m_size (canvas::size_t (0, 0)),
+    m_has_layout (false)
+  {}
+
+  void add_label (const canvas::range_t &r,
+		  styled_string text,
+		  style::id_t style_id,
+		  label_kind kind = label_kind::TEXT);
+
+  canvas::size_t get_size ()
+  {
+    ensure_layout ();
+    return m_size;
+  }
+
+  void paint_to_canvas (canvas &canvas,
+			canvas::coord_t offset,
+			const theme &theme);
+
+  void debug (const style_manager &sm);
+
+ private:
+  /* A particular label within an x_ruler.
+     Consider e.g.:
+
+     #   x:  01234567890123456789012345678901234567890123456789
+     # y: 0: ├───────┬───────┼───────┬───────┼───────┬───────┤
+     #    1:         │               │               │
+     #    2:       label A         label B          label C
+     #
+
+     Then "label A" is:
+
+     #               m_connector_x == 8
+     #               V
+     #   x:  0123456789012
+     # y: 0:         ┬
+     #    1:         │
+     #    2:       label A
+     #   x:  0123456789012
+     #             ^
+     #             m_text_coord.x == 6
+
+     and m_text_coord is (2, 6).
+     The y cooordinates are stored with respect to label_dir::BELOW;
+     for label_dir::ABOVE we flip them when painting the ruler.  */
+  class label
+  {
+    friend class x_ruler;
+  public:
+    label (const canvas::range_t &range, styled_string text, style::id_t style_id,
+	   label_kind kind);
+
+    bool operator< (const label &other) const;
+
+  private:
+    canvas::range_t m_range;
+    styled_string m_text;
+    style::id_t m_style_id;
+    label_kind m_kind;
+    canvas::rect_t m_text_rect; // includes any border
+    int m_connector_x;
+  };
+
+  void ensure_layout ();
+  void update_layout ();
+  int get_canvas_y (int rel_y) const;
+
+  label_dir m_label_dir;
+  std::vector<label> m_labels;
+  canvas::size_t m_size;
+  bool m_has_layout = false;
+
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_RULER_H */
diff --git a/gcc/text-art/selftests.cc b/gcc/text-art/selftests.cc
new file mode 100644
index 00000000000..60ad003b549
--- /dev/null
+++ b/gcc/text-art/selftests.cc
@@ -0,0 +1,77 @@
+/* Selftests for text art.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "selftest.h"
+#include "pretty-print.h"
+#include "text-art/selftests.h"
+#include "text-art/canvas.h"
+
+#if CHECKING_P
+
+/* Run all tests, aborting if any fail.  */
+
+void
+selftest::text_art_tests ()
+{
+  text_art_style_cc_tests ();
+  text_art_styled_string_cc_tests ();
+
+  text_art_box_drawing_cc_tests ();
+  text_art_canvas_cc_tests ();
+  text_art_ruler_cc_tests ();
+  text_art_table_cc_tests ();
+  text_art_widget_cc_tests ();
+}
+
+/* Implementation detail of ASSERT_CANVAS_STREQ.  */
+
+void
+selftest::assert_canvas_streq (const location &loc,
+			       const text_art::canvas &canvas,
+			       pretty_printer *pp,
+			       const char *expected_str)
+{
+  canvas.print_to_pp (pp);
+  if (0)
+    fprintf (stderr, "%s\n", pp_formatted_text (pp));
+  ASSERT_STREQ_AT (loc, pp_formatted_text (pp), expected_str);
+}
+
+/* Implementation detail of ASSERT_CANVAS_STREQ.  */
+
+void
+selftest::assert_canvas_streq (const location &loc,
+			       const text_art::canvas &canvas,
+			       bool styled,
+			       const char *expected_str)
+{
+  pretty_printer pp;
+  if (styled)
+    {
+      pp_show_color (&pp) = true;
+      pp.url_format = URL_FORMAT_DEFAULT;
+    }
+  assert_canvas_streq (loc, canvas, &pp, expected_str);
+}
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/selftests.h b/gcc/text-art/selftests.h
new file mode 100644
index 00000000000..706a1d8b5d6
--- /dev/null
+++ b/gcc/text-art/selftests.h
@@ -0,0 +1,60 @@
+/* Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_SELFTESTS_H
+#define GCC_TEXT_ART_SELFTESTS_H
+
+#if CHECKING_P
+
+#include "text-art/types.h"
+
+namespace selftest {
+
+extern void text_art_box_drawing_cc_tests ();
+extern void text_art_canvas_cc_tests ();
+extern void text_art_ruler_cc_tests ();
+extern void text_art_style_cc_tests ();
+extern void text_art_styled_string_cc_tests ();
+extern void text_art_table_cc_tests ();
+extern void text_art_widget_cc_tests ();
+
+extern void text_art_tests ();
+
+extern void assert_canvas_streq (const location &loc,
+				 const text_art::canvas &canvas,
+				 pretty_printer *pp,
+				 const char *expected_str);
+extern void assert_canvas_streq (const location &loc,
+				 const text_art::canvas &canvas,
+				 bool styled,
+				 const char *expected_str);
+
+#define ASSERT_CANVAS_STREQ(CANVAS, STYLED, EXPECTED_STR)		\
+  SELFTEST_BEGIN_STMT							\
+    assert_canvas_streq ((SELFTEST_LOCATION),				\
+			 (CANVAS),					\
+			 (STYLED), 					\
+			 (EXPECTED_STR));				\
+  SELFTEST_END_STMT
+
+} /* end of namespace selftest.  */
+
+#endif /* #if CHECKING_P */
+
+#endif /* GCC_TEXT_ART_SELFTESTS_H */
diff --git a/gcc/text-art/style.cc b/gcc/text-art/style.cc
new file mode 100644
index 00000000000..00b056336fc
--- /dev/null
+++ b/gcc/text-art/style.cc
@@ -0,0 +1,632 @@
+/* Classes for styling text cells (color, URLs).
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_ALGORITHM
+#define INCLUDE_MEMORY
+#include "system.h"
+#include "coretypes.h"
+#include "make-unique.h"
+#include "pretty-print.h"
+#include "intl.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/types.h"
+#include "color-macros.h"
+
+using namespace text_art;
+
+/* class text_art::style.  */
+
+style &
+style::set_style_url (const char *url)
+{
+  m_url.clear ();
+  while (*url)
+    m_url.push_back (*(url++));
+  return *this;
+}
+
+/* class text_art::style::color.  */
+
+bool
+style::color::operator== (const style::color &other) const
+{
+  if (m_kind != other.m_kind)
+    return false;
+  switch (m_kind)
+    {
+    default:
+      gcc_unreachable ();
+    case kind::NAMED:
+      return (u.m_named.m_name == other.u.m_named.m_name
+	      && u.m_named.m_bright == other.u.m_named.m_bright);
+    case kind::BITS_8:
+      return u.m_8bit == other.u.m_8bit;
+    case kind::BITS_24:
+      return (u.m_24bit.r == other.u.m_24bit.r
+	      && u.m_24bit.g == other.u.m_24bit.g
+	      && u.m_24bit.b == other.u.m_24bit.b);
+    }
+}
+
+static void
+ensure_separator (pretty_printer *pp, bool &need_separator)
+{
+  if (need_separator)
+    pp_string (pp, COLOR_SEPARATOR);
+  need_separator = true;
+}
+
+void
+style::color::print_sgr (pretty_printer *pp,
+			 bool fg,
+			 bool &need_separator) const
+{
+  switch (m_kind)
+    {
+    default:
+      gcc_unreachable ();
+    case kind::NAMED:
+      {
+	static const char * const fg_normal[] = {"", // reset, for DEFAULT
+						 COLOR_FG_BLACK,
+						 COLOR_FG_RED,
+						 COLOR_FG_GREEN,
+						 COLOR_FG_YELLOW,
+						 COLOR_FG_BLUE,
+						 COLOR_FG_MAGENTA,
+						 COLOR_FG_CYAN,
+						 COLOR_FG_WHITE};
+	static const char * const fg_bright[] = {"", // reset, for DEFAULT
+						 COLOR_FG_BRIGHT_BLACK,
+						 COLOR_FG_BRIGHT_RED,
+						 COLOR_FG_BRIGHT_GREEN,
+						 COLOR_FG_BRIGHT_YELLOW,
+						 COLOR_FG_BRIGHT_BLUE,
+						 COLOR_FG_BRIGHT_MAGENTA,
+						 COLOR_FG_BRIGHT_CYAN,
+						 COLOR_FG_BRIGHT_WHITE};
+	static const char * const bg_normal[] = {"", // reset, for DEFAULT
+						 COLOR_BG_BLACK,
+						 COLOR_BG_RED,
+						 COLOR_BG_GREEN,
+						 COLOR_BG_YELLOW,
+						 COLOR_BG_BLUE,
+						 COLOR_BG_MAGENTA,
+						 COLOR_BG_CYAN,
+						 COLOR_BG_WHITE};
+	static const char * const bg_bright[] = {"", // reset, for DEFAULT
+						 COLOR_BG_BRIGHT_BLACK,
+						 COLOR_BG_BRIGHT_RED,
+						 COLOR_BG_BRIGHT_GREEN,
+						 COLOR_BG_BRIGHT_YELLOW,
+						 COLOR_BG_BRIGHT_BLUE,
+						 COLOR_BG_BRIGHT_MAGENTA,
+						 COLOR_BG_BRIGHT_CYAN,
+						 COLOR_BG_BRIGHT_WHITE};
+	STATIC_ASSERT (ARRAY_SIZE (fg_normal) == ARRAY_SIZE (fg_bright));
+	STATIC_ASSERT (ARRAY_SIZE (fg_normal) == ARRAY_SIZE (bg_normal));
+	STATIC_ASSERT (ARRAY_SIZE (fg_normal) == ARRAY_SIZE (bg_bright));
+	gcc_assert ((size_t)u.m_named.m_name < ARRAY_SIZE (fg_normal));
+	const char *const *arr;
+	if (fg)
+	  arr = u.m_named.m_bright ? fg_bright : fg_normal;
+	else
+	  arr = u.m_named.m_bright ? bg_bright : bg_normal;
+	const char *str = arr[(size_t)u.m_named.m_name];
+	if (strlen (str) > 0)
+	  {
+	    ensure_separator (pp, need_separator);
+	    pp_string (pp, str);
+	  }
+      }
+      break;
+    case kind::BITS_8:
+      {
+	ensure_separator (pp, need_separator);
+	if (fg)
+	  pp_string (pp, "38");
+	else
+	  pp_string (pp, "48");
+	pp_printf (pp, ";5;%i", (int)u.m_8bit);
+      }
+      break;
+    case kind::BITS_24:
+      {
+	ensure_separator (pp, need_separator);
+	if (fg)
+	  pp_string (pp, "38");
+	else
+	  pp_string (pp, "48");
+	pp_printf (pp, ";2;%i;%i;%i",
+		   (int)u.m_24bit.r,
+		   (int)u.m_24bit.g,
+		   (int)u.m_24bit.b);
+      }
+      break;
+    }
+}
+
+/* class text_art::style.  */
+
+/* See https://www.ecma-international.org/wp-content/uploads/ECMA-48_5th_edition_june_1991.pdf
+   GRCM - GRAPHIC RENDITION COMBINATION MODE can be "REPLACING" or
+   "CUMULATIVE", which affects whether we need to respecify all attributes
+   at each SGR, or can accumulate them.  Looks like we can't rely on the value
+   of this, so we have to emit a single SGR for all changes, with a "0" reset
+   at the front, forcing it to be effectively replacing.  */
+
+void
+style::print_changes (pretty_printer *pp,
+		      const style &old_style,
+		      const style &new_style)
+{
+  if (pp_show_color (pp))
+    {
+      bool needs_sgr = ((old_style.m_bold != new_style.m_bold)
+			|| (old_style.m_underscore != new_style.m_underscore)
+			|| (old_style.m_blink != new_style.m_blink)
+			|| (old_style.m_fg_color != new_style.m_fg_color)
+			|| (old_style.m_bg_color != new_style.m_bg_color));
+      if (needs_sgr)
+	{
+	  bool emit_reset = (old_style.m_bold
+			     || new_style.m_bold
+			     || old_style.m_underscore
+			     || new_style.m_underscore
+			     || old_style.m_blink
+			     || new_style.m_blink);
+	  bool need_separator = false;
+
+	  pp_string (pp, SGR_START);
+	  if (emit_reset)
+	    {
+	      pp_string (pp, COLOR_NONE);
+	      need_separator = true;
+	    }
+	  if (new_style.m_bold)
+	    {
+	      gcc_assert (emit_reset);
+	      ensure_separator (pp, need_separator);
+	      pp_string (pp, COLOR_BOLD);
+	    }
+	  if (new_style.m_underscore)
+	    {
+	      gcc_assert (emit_reset);
+	      ensure_separator (pp, need_separator);
+	      pp_string (pp, COLOR_UNDERSCORE);
+	    }
+	  if (new_style.m_blink)
+	    {
+	      gcc_assert (emit_reset);
+	      ensure_separator (pp, need_separator);
+	      pp_string (pp, COLOR_BLINK);
+	    }
+	  new_style.m_fg_color.print_sgr (pp, true, need_separator);
+	  new_style.m_bg_color.print_sgr (pp, false, need_separator);
+	  pp_string (pp, SGR_END);
+	}
+    }
+
+  if (old_style.m_url != new_style.m_url)
+    {
+      if (!old_style.m_url.empty ())
+	pp_end_url (pp);
+      if (pp->url_format != URL_FORMAT_NONE
+	  && !new_style.m_url.empty ())
+	{
+	  /* Adapted from pp_begin_url, but encoding the
+	     chars to UTF-8 on the fly, rather than converting
+	     to a buffer.  */
+	  pp_string (pp, "\33]8;;");
+	  for (auto ch : new_style.m_url)
+	    pp_unicode_character (pp, ch);
+	  switch (pp->url_format)
+	    {
+	    default:
+	    case URL_FORMAT_NONE:
+	      gcc_unreachable ();
+	    case URL_FORMAT_ST:
+	      pp_string (pp, "\33\\");
+	      break;
+	    case URL_FORMAT_BEL:
+	      pp_string (pp, "\a");
+	      break;
+	    }
+	}
+    }
+}
+
+/* class text_art::style_manager.  */
+
+style_manager::style_manager ()
+{
+  // index 0 will be the default style
+  m_styles.push_back (style ());
+}
+
+style::id_t
+style_manager::get_or_create_id (const style &s)
+{
+  // For now, linear search
+  std::vector<style>::iterator existing
+    (std::find (m_styles.begin (), m_styles.end (), s));
+
+  /* If found, return index of slot.  */
+  if (existing != m_styles.end ())
+    return std::distance (m_styles.begin (), existing);
+
+  /* Not found.  */
+
+  /* styled_str uses 7 bits for style information, so we can only support
+     up to 128 different style combinations.
+     Gracefully fail by turning off styling when this limit is reached.  */
+  if (m_styles.size () >= 127)
+    return 0;
+
+  m_styles.push_back (s);
+  return m_styles.size () - 1;
+}
+
+void
+style_manager::print_any_style_changes (pretty_printer *pp,
+					style::id_t old_id,
+					style::id_t new_id) const
+{
+  gcc_assert (pp);
+  if (old_id == new_id)
+    return;
+
+  const style &old_style = m_styles[old_id];
+  const style &new_style = m_styles[new_id];
+  gcc_assert (!(old_style == new_style));
+  style::print_changes (pp, old_style, new_style);
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+void
+assert_style_change_streq (const location &loc,
+			   const style &old_style,
+			   const style &new_style,
+			   const char *expected_str)
+{
+  pretty_printer pp;
+  pp_show_color (&pp) = true;
+  style::print_changes (&pp, old_style, new_style);
+  ASSERT_STREQ_AT (loc, pp_formatted_text (&pp), expected_str);
+}
+
+#define ASSERT_STYLE_CHANGE_STREQ(OLD_STYLE, NEW_STYLE, EXPECTED_STR) \
+  SELFTEST_BEGIN_STMT						      \
+    assert_style_change_streq ((SELFTEST_LOCATION),		      \
+			       (OLD_STYLE),			      \
+			       (NEW_STYLE),			      \
+			       (EXPECTED_STR));			      \
+  SELFTEST_END_STMT
+
+static void
+test_bold ()
+{
+  style_manager sm;
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style plain;
+  ASSERT_EQ (sm.get_or_create_id (plain), 0);
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style bold;
+  bold.m_bold = true;
+
+  ASSERT_EQ (sm.get_or_create_id (bold), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+  ASSERT_EQ (sm.get_or_create_id (bold), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+
+  ASSERT_STYLE_CHANGE_STREQ (plain, bold, "\33[00;01m\33[K");
+  ASSERT_STYLE_CHANGE_STREQ (bold, plain, "\33[00m\33[K");
+}
+
+static void
+test_underscore ()
+{
+  style_manager sm;
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style plain;
+  ASSERT_EQ (sm.get_or_create_id (plain), 0);
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style underscore;
+  underscore.m_underscore = true;
+
+  ASSERT_EQ (sm.get_or_create_id (underscore), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+  ASSERT_EQ (sm.get_or_create_id (underscore), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+
+  ASSERT_STYLE_CHANGE_STREQ (plain, underscore, "\33[00;04m\33[K");
+  ASSERT_STYLE_CHANGE_STREQ (underscore, plain, "\33[00m\33[K");
+}
+
+static void
+test_blink ()
+{
+  style_manager sm;
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style plain;
+  ASSERT_EQ (sm.get_or_create_id (plain), 0);
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style blink;
+  blink.m_blink = true;
+
+  ASSERT_EQ (sm.get_or_create_id (blink), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+  ASSERT_EQ (sm.get_or_create_id (blink), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+
+  ASSERT_STYLE_CHANGE_STREQ (plain, blink, "\33[00;05m\33[K");
+  ASSERT_STYLE_CHANGE_STREQ (blink, plain, "\33[00m\33[K");
+}
+
+#define ASSERT_NAMED_COL_STREQ(NAMED_COLOR, FG, BRIGHT, EXPECTED_STR) \
+  SELFTEST_BEGIN_STMT						      \
+  {								      \
+    style plain;						      \
+    style s;							      \
+    if (FG)							      \
+      s.m_fg_color = style::color ((NAMED_COLOR), (BRIGHT));	      \
+    else							      \
+      s.m_bg_color = style::color ((NAMED_COLOR), (BRIGHT));	      \
+    assert_style_change_streq ((SELFTEST_LOCATION),		      \
+			       plain,				      \
+			       s,				      \
+			       (EXPECTED_STR));			      \
+  }								      \
+  SELFTEST_END_STMT
+
+static void
+test_named_colors ()
+{
+  /* Foreground colors.  */
+  {
+    const bool fg = true;
+    {
+      const bool bright = false;
+      ASSERT_NAMED_COL_STREQ (style::named_color::DEFAULT, fg, bright, "");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLACK, fg, bright,
+			      "^[[30m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::RED, fg, bright,
+			      "^[[31m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::GREEN, fg, bright,
+			      "^[[32m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::YELLOW, fg, bright,
+			      "^[[33m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLUE, fg, bright,
+			      "^[[34m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::MAGENTA, fg, bright,
+			      "^[[35m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::CYAN, fg, bright,
+			      "^[[36m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::WHITE, fg, bright,
+			      "^[[37m^[[K");
+    }
+    {
+      const bool bright = true;
+      ASSERT_NAMED_COL_STREQ (style::named_color::DEFAULT, fg, bright,
+			      "^[[m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLACK, fg, bright,
+			      "^[[90m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::RED, fg, bright,
+			      "^[[91m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::GREEN, fg, bright,
+			      "^[[92m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::YELLOW, fg, bright,
+			      "^[[93m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLUE, fg, bright,
+			      "^[[94m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::MAGENTA, fg, bright,
+			      "^[[95m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::CYAN, fg, bright,
+			      "^[[96m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::WHITE, fg, bright,
+			      "^[[97m^[[K");
+    }
+  }
+
+  /* Background colors.  */
+  {
+    const bool fg = false;
+    {
+      const bool bright = false;
+      ASSERT_NAMED_COL_STREQ (style::named_color::DEFAULT, fg, bright, "");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLACK, fg, bright,
+			      "^[[40m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::RED, fg, bright,
+			      "^[[41m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::GREEN, fg, bright,
+			      "^[[42m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::YELLOW, fg, bright,
+			      "^[[43m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLUE, fg, bright,
+			      "^[[44m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::MAGENTA, fg, bright,
+			      "^[[45m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::CYAN, fg, bright,
+			      "^[[46m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::WHITE, fg, bright,
+			      "^[[47m^[[K");
+    }
+    {
+      const bool bright = true;
+      ASSERT_NAMED_COL_STREQ (style::named_color::DEFAULT, fg, bright,
+			      "^[[m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLACK, fg, bright,
+			      "^[[100m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::RED, fg, bright,
+			      "^[[101m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::GREEN, fg, bright,
+			      "^[[102m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::YELLOW, fg, bright,
+			      "^[[103m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::BLUE, fg, bright,
+			      "^[[104m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::MAGENTA, fg, bright,
+			      "^[[105m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::CYAN, fg, bright,
+			      "^[[106m^[[K");
+      ASSERT_NAMED_COL_STREQ (style::named_color::WHITE, fg, bright,
+			      "^[[107m^[[K");
+    }
+  }
+}
+
+#define ASSERT_8_BIT_COL_STREQ(COL_VAL, FG, EXPECTED_STR) \
+  SELFTEST_BEGIN_STMT						      \
+  {								      \
+    style plain;						      \
+    style s;							      \
+    if (FG)							      \
+      s.m_fg_color = style::color (COL_VAL);			      \
+    else							      \
+      s.m_bg_color = style::color (COL_VAL);			      \
+    assert_style_change_streq ((SELFTEST_LOCATION),		      \
+			       plain,				      \
+			       s,				      \
+			       (EXPECTED_STR));			      \
+  }								      \
+  SELFTEST_END_STMT
+
+static void
+test_8_bit_colors ()
+{
+  /* Foreground colors.  */
+  {
+    const bool fg = true;
+    /* 0-15: standard and high-intensity standard colors.  */
+    ASSERT_8_BIT_COL_STREQ (0, fg, "^[[38;5;0m^[[K");
+    ASSERT_8_BIT_COL_STREQ (15, fg, "^[[38;5;15m^[[K");
+    /* 16-231: 6x6x6 color cube.  */
+    ASSERT_8_BIT_COL_STREQ (16, fg, "^[[38;5;16m^[[K");
+    ASSERT_8_BIT_COL_STREQ (231, fg, "^[[38;5;231m^[[K");
+    /* 232-255: grayscale.  */
+    ASSERT_8_BIT_COL_STREQ (232, fg, "^[[38;5;232m^[[K");
+    ASSERT_8_BIT_COL_STREQ (255, fg, "^[[38;5;255m^[[K");
+  }
+  /* Background colors.  */
+  {
+    const bool fg = false;
+    /* 0-15: standard and high-intensity standard colors.  */
+    ASSERT_8_BIT_COL_STREQ (0, fg, "^[[48;5;0m^[[K");
+    ASSERT_8_BIT_COL_STREQ (15, fg, "^[[48;5;15m^[[K");
+    /* 16-231: 6x6x6 color cube.  */
+    ASSERT_8_BIT_COL_STREQ (16, fg, "^[[48;5;16m^[[K");
+    ASSERT_8_BIT_COL_STREQ (231, fg, "^[[48;5;231m^[[K");
+    /* 232-255: grayscale.  */
+    ASSERT_8_BIT_COL_STREQ (232, fg, "^[[48;5;232m^[[K");
+    ASSERT_8_BIT_COL_STREQ (255, fg, "^[[48;5;255m^[[K");
+  }
+}
+
+#define ASSERT_24_BIT_COL_STREQ(R, G, B, FG, EXPECTED_STR)	      \
+  SELFTEST_BEGIN_STMT						      \
+  {								      \
+    style plain;						      \
+    style s;							      \
+    if (FG)							      \
+      s.m_fg_color = style::color ((R), (G), (B));		      \
+    else							      \
+      s.m_bg_color = style::color ((R), (G), (B));		      \
+    assert_style_change_streq ((SELFTEST_LOCATION),		      \
+			       plain,				      \
+			       s,				      \
+			       (EXPECTED_STR));			      \
+  }								      \
+  SELFTEST_END_STMT
+
+static void
+test_24_bit_colors ()
+{
+  /* Foreground colors.  */
+  {
+    const bool fg = true;
+    // #F3FAF2:
+    ASSERT_24_BIT_COL_STREQ (0xf3, 0xfa, 0xf2, fg,
+			     "^[[38;2;243;250;242m^[[K");
+  }
+  /* Background colors.  */
+  {
+    const bool fg = false;
+    // #FDF7E7
+    ASSERT_24_BIT_COL_STREQ (0xfd, 0xf7, 0xe7, fg,
+			     "^[[48;2;253;247;231m^[[K");
+  }
+}
+
+static void
+test_style_combinations ()
+{
+  style_manager sm;
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style plain;
+  ASSERT_EQ (sm.get_or_create_id (plain), 0);
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  style bold;
+  bold.m_bold = true;
+
+  ASSERT_EQ (sm.get_or_create_id (bold), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+  ASSERT_EQ (sm.get_or_create_id (bold), 1);
+  ASSERT_EQ (sm.get_num_styles (), 2);
+
+  style magenta_on_blue;
+  magenta_on_blue.m_fg_color = style::named_color::MAGENTA;
+  magenta_on_blue.m_bg_color = style::named_color::BLUE;
+  ASSERT_EQ (sm.get_or_create_id (magenta_on_blue), 2);
+  ASSERT_EQ (sm.get_num_styles (), 3);
+  ASSERT_EQ (sm.get_or_create_id (magenta_on_blue), 2);
+  ASSERT_EQ (sm.get_num_styles (), 3);
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_style_cc_tests ()
+{
+  test_bold ();
+  test_underscore ();
+  test_blink ();
+  test_named_colors ();
+  test_8_bit_colors ();
+  test_24_bit_colors ();
+  test_style_combinations ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/styled-string.cc b/gcc/text-art/styled-string.cc
new file mode 100644
index 00000000000..cd176b2313f
--- /dev/null
+++ b/gcc/text-art/styled-string.cc
@@ -0,0 +1,1107 @@
+/* Implementation of text_art::styled_string.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_MEMORY
+#include "system.h"
+#include "coretypes.h"
+#include "make-unique.h"
+#include "pretty-print.h"
+#include "intl.h"
+#include "diagnostic.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/types.h"
+#include "color-macros.h"
+
+using namespace text_art;
+
+namespace {
+
+/* Support class for parsing text containing escape codes.
+   See e.g. https://en.wikipedia.org/wiki/ANSI_escape_code
+   We only support the codes that pretty-print.cc can generate.  */
+
+class escape_code_parser
+{
+public:
+  escape_code_parser (style_manager &sm,
+		      std::vector<styled_unichar> &out)
+  : m_sm (sm),
+    m_out (out),
+    m_cur_style_obj (),
+    m_cur_style_id (style::id_plain),
+    m_state (state::START)
+  {
+  }
+
+  void on_char (cppchar_t ch)
+  {
+    switch (m_state)
+      {
+      default:
+	gcc_unreachable ();
+      case state::START:
+	if (ch == '\033')
+	  {
+	    /* The start of an escape sequence.  */
+	    m_state = state::AFTER_ESC;
+	    return;
+	  }
+	break;
+      case state::AFTER_ESC:
+	if (ch == '[')
+	  {
+	    /* ESC [ is a Control Sequence Introducer.  */
+	    m_state = state::CS_PARAMETER_BYTES;
+	    return;
+	  }
+	else if (ch == ']')
+	  {
+	    /* ESC ] is an Operating System Command.  */
+	    m_state = state::WITHIN_OSC;
+	    return;
+	  }
+	break;
+      case state::CS_PARAMETER_BYTES:
+	if (parameter_byte_p (ch))
+	  {
+	    m_parameter_bytes.push_back ((char)ch);
+	    return;
+	  }
+	else if (intermediate_byte_p (ch))
+	  {
+	    m_intermediate_bytes.push_back ((char)ch);
+	    m_state = state::CS_INTERMEDIATE_BYTES;
+	    return;
+	  }
+	else if (final_byte_p (ch))
+	  {
+	    on_final_csi_char (ch);
+	    return;
+	  }
+	break;
+      case state::CS_INTERMEDIATE_BYTES:
+	/* Expect zero or more intermediate bytes.  */
+	if (intermediate_byte_p (ch))
+	  {
+	    m_intermediate_bytes.push_back ((char)ch);
+	    return;
+	  }
+	else if (final_byte_p (ch))
+	  {
+	    on_final_csi_char (ch);
+	    return;
+	  }
+	break;
+      case state::WITHIN_OSC:
+	/* Accumulate chars into m_osc_string, until we see an ST or a BEL.  */
+	{
+	  /* Check for ESC \, the String Terminator (aka "ST").  */
+	  if (ch == '\\'
+	      && m_osc_string.size () > 0
+	      && m_osc_string.back () == '\033')
+	    {
+	      m_osc_string.pop_back ();
+	      on_final_osc_char ();
+	      return;
+	    }
+	  else if (ch == '\a')
+	    {
+	      // BEL
+	      on_final_osc_char ();
+	      return;
+	    }
+	  m_osc_string.push_back (ch);
+	  return;
+	}
+	break;
+      }
+
+    /* Test of handling U+FE0F VARIATION SELECTOR-16 to select the emoji
+       variation for the previous character.  */
+    if (ch == 0xFE0F)
+      {
+	if (m_out.size () > 0)
+	  m_out.back ().set_emoji_variant ();
+	return;
+      }
+
+    if (cpp_is_combining_char (ch))
+      {
+	if (m_out.size () > 0)
+	  {
+	    m_out.back ().add_combining_char (ch);
+	    return;
+	  }
+      }
+    /* By default, add the char.  */
+    m_out.push_back (styled_unichar (ch, false, m_cur_style_id));
+  }
+
+private:
+  void on_final_csi_char (cppchar_t ch)
+  {
+    switch (ch)
+      {
+      default:
+	/* Unrecognized.  */
+	break;
+      case 'm':
+	{
+	  /* SGR control sequence.  */
+	  if (m_parameter_bytes.empty ())
+	    reset_style ();
+	  std::vector<int> params (params_from_decimal ());
+	  for (auto iter = params.begin (); iter != params.end (); )
+	    {
+	      const int param = *iter;
+	      switch (param)
+		{
+		default:
+		  /* Unrecognized SGR parameter.  */
+		  break;
+		case 0:
+		  reset_style ();
+		  break;
+		case 1:
+		  set_style_bold ();
+		  break;
+		case 4:
+		  set_style_underscore ();
+		  break;
+		case 5:
+		  set_style_blink ();
+		  break;
+
+		/* Named foreground colors.  */
+		case 30:
+		  set_style_fg_color (style::named_color::BLACK);
+		  break;
+		case 31:
+		  set_style_fg_color (style::named_color::RED);
+		  break;
+		case 32:
+		  set_style_fg_color (style::named_color::GREEN);
+		  break;
+		case 33:
+		  set_style_fg_color (style::named_color::YELLOW);
+		  break;
+		case 34:
+		  set_style_fg_color (style::named_color::BLUE);
+		  break;
+		case 35:
+		  set_style_fg_color (style::named_color::MAGENTA);
+		  break;
+		case 36:
+		  set_style_fg_color (style::named_color::CYAN);
+		  break;
+		case 37:
+		  set_style_fg_color (style::named_color::WHITE);
+		  break;
+
+		  /* 8-bit and 24-bit color */
+		case 38:
+		case 48:
+		  {
+		    const bool fg = (param == 38);
+		    iter++;
+		    if (iter != params.end ())
+		      switch (*(iter++))
+			{
+			default:
+			  break;
+			case 5:
+			  /* 8-bit color.  */
+			  if (iter != params.end ())
+			    {
+			      const uint8_t col = *(iter++);
+			      if (fg)
+				set_style_fg_color (style::color (col));
+			      else
+				set_style_bg_color (style::color (col));
+			    }
+			  continue;
+			case 2:
+			  /* 24-bit color.  */
+			  if (iter != params.end ())
+			    {
+			      const uint8_t r = *(iter++);
+			      if (iter != params.end ())
+				{
+				  const uint8_t g = *(iter++);
+				  if (iter != params.end ())
+				    {
+				      const uint8_t b = *(iter++);
+				      if (fg)
+					set_style_fg_color (style::color (r,
+									  g,
+									  b));
+				      else
+					set_style_bg_color (style::color (r,
+									  g,
+									  b));
+				    }
+				}
+			    }
+			  continue;
+			}
+		    continue;
+		  }
+		  break;
+
+		/* Named background colors.  */
+		case 40:
+		  set_style_bg_color (style::named_color::BLACK);
+		  break;
+		case 41:
+		  set_style_bg_color (style::named_color::RED);
+		  break;
+		case 42:
+		  set_style_bg_color (style::named_color::GREEN);
+		  break;
+		case 43:
+		  set_style_bg_color (style::named_color::YELLOW);
+		  break;
+		case 44:
+		  set_style_bg_color (style::named_color::BLUE);
+		  break;
+		case 45:
+		  set_style_bg_color (style::named_color::MAGENTA);
+		  break;
+		case 46:
+		  set_style_bg_color (style::named_color::CYAN);
+		  break;
+		case 47:
+		  set_style_bg_color (style::named_color::WHITE);
+		  break;
+
+		/* Named foreground colors, bright.  */
+		case 90:
+		  set_style_fg_color (style::color (style::named_color::BLACK,
+						    true));
+		  break;
+		case 91:
+		  set_style_fg_color (style::color (style::named_color::RED,
+						    true));
+		  break;
+		case 92:
+		  set_style_fg_color (style::color (style::named_color::GREEN,
+						    true));
+		  break;
+		case 93:
+		  set_style_fg_color (style::color (style::named_color::YELLOW,
+						    true));
+		  break;
+		case 94:
+		  set_style_fg_color (style::color (style::named_color::BLUE,
+						    true));
+		  break;
+		case 95:
+		  set_style_fg_color (style::color (style::named_color::MAGENTA,
+						    true));
+		  break;
+		case 96:
+		  set_style_fg_color (style::color (style::named_color::CYAN,
+						    true));
+		  break;
+		case 97:
+		  set_style_fg_color (style::color (style::named_color::WHITE,
+						    true));
+		  break;
+
+		/* Named foreground colors, bright.  */
+		case 100:
+		  set_style_bg_color (style::color (style::named_color::BLACK,
+						    true));
+		  break;
+		case 101:
+		  set_style_bg_color (style::color (style::named_color::RED,
+						    true));
+		  break;
+		case 102:
+		  set_style_bg_color (style::color (style::named_color::GREEN,
+						    true));
+		  break;
+		case 103:
+		  set_style_bg_color (style::color (style::named_color::YELLOW,
+						    true));
+		  break;
+		case 104:
+		  set_style_bg_color (style::color (style::named_color::BLUE,
+						    true));
+		  break;
+		case 105:
+		  set_style_bg_color (style::color (style::named_color::MAGENTA,
+						    true));
+		  break;
+		case 106:
+		  set_style_bg_color (style::color (style::named_color::CYAN,
+						    true));
+		  break;
+		case 107:
+		  set_style_bg_color (style::color (style::named_color::WHITE,
+						    true));
+		  break;
+		}
+	      ++iter;
+	    }
+	}
+	break;
+      }
+    m_parameter_bytes.clear ();
+    m_intermediate_bytes.clear ();
+    m_state = state::START;
+  }
+
+  void on_final_osc_char ()
+  {
+    if (!m_osc_string.empty ())
+      {
+	switch (m_osc_string[0])
+	  {
+	  default:
+	    break;
+	  case '8':
+	    /* Hyperlink support; see:
+	       https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
+	       We don't support params, so we expect either:
+	       (a) "8;;URL" to begin a url (see pp_begin_url), or
+	       (b) "8;;" to end a URL (see pp_end_url).  */
+	    if (m_osc_string.size () >= 3
+		&& m_osc_string[1] == ';'
+		&& m_osc_string[2] == ';')
+	      {
+		set_style_url (m_osc_string.begin () + 3,
+			       m_osc_string.end ());
+	      }
+	    break;
+	  }
+      }
+    m_osc_string.clear ();
+    m_state = state::START;
+  }
+
+  std::vector<int> params_from_decimal () const
+  {
+    std::vector<int> result;
+
+    int curr_int = -1;
+    for (auto param_ch : m_parameter_bytes)
+      {
+	if (param_ch >= '0' && param_ch <= '9')
+	  {
+	    if (curr_int == -1)
+	      curr_int = 0;
+	    else
+	      curr_int *= 10;
+	    curr_int += param_ch - '0';
+	  }
+	else
+	  {
+	    if (curr_int != -1)
+	      {
+		result.push_back (curr_int);
+		curr_int = -1;
+	      }
+	  }
+      }
+    if (curr_int != -1)
+      result.push_back (curr_int);
+    return result;
+  }
+
+  void refresh_style_id ()
+  {
+    m_cur_style_id = m_sm.get_or_create_id (m_cur_style_obj);
+  }
+  void reset_style ()
+  {
+    m_cur_style_obj = style ();
+    refresh_style_id ();
+  }
+  void set_style_bold ()
+  {
+    m_cur_style_obj.m_bold = true;
+    refresh_style_id ();
+  }
+  void set_style_underscore ()
+  {
+    m_cur_style_obj.m_underscore = true;
+    refresh_style_id ();
+  }
+  void set_style_blink ()
+  {
+    m_cur_style_obj.m_blink = true;
+    refresh_style_id ();
+  }
+  void set_style_fg_color (style::color color)
+  {
+    m_cur_style_obj.m_fg_color = color;
+    refresh_style_id ();
+  }
+  void set_style_bg_color (style::color color)
+  {
+    m_cur_style_obj.m_bg_color = color;
+    refresh_style_id ();
+  }
+  void set_style_url (std::vector<cppchar_t>::iterator begin,
+		      std::vector<cppchar_t>::iterator end)
+  {
+    // The empty string means "no URL"
+    m_cur_style_obj.m_url = std::vector<cppchar_t> (begin, end);
+    refresh_style_id ();
+  }
+
+  static bool parameter_byte_p (cppchar_t ch)
+  {
+    return ch >= 0x30 && ch <= 0x3F;
+  }
+
+  static bool intermediate_byte_p (cppchar_t ch)
+  {
+    return ch >= 0x20 && ch <= 0x2F;
+  }
+
+  static bool final_byte_p (cppchar_t ch)
+  {
+    return ch >= 0x40 && ch <= 0x7E;
+  }
+
+  style_manager &m_sm;
+  std::vector<styled_unichar> &m_out;
+
+  style m_cur_style_obj;
+  style::id_t m_cur_style_id;
+
+  /* Handling of control sequences.  */
+  enum class state
+  {
+   START,
+
+   /* After ESC, expecting '['.  */
+   AFTER_ESC,
+
+   /* Expecting zero or more parameter bytes, an
+      intermediate byte, or a final byte.  */
+   CS_PARAMETER_BYTES,
+
+   /* Expecting zero or more intermediate bytes, or a final byte.  */
+   CS_INTERMEDIATE_BYTES,
+
+   /* Within OSC.  */
+   WITHIN_OSC
+
+  } m_state;
+  std::vector<char> m_parameter_bytes;
+  std::vector<char> m_intermediate_bytes;
+  std::vector<cppchar_t> m_osc_string;
+};
+
+} // anon namespace
+
+/* class text_art::styled_string.  */
+
+/* Construct a styled_string from STR.
+   STR is assumed to be UTF-8 encoded and 0-terminated.
+
+   Parse SGR formatting chars from being in-band (within in the sequence
+   of chars) to being out-of-band, as style elements.
+   We only support parsing the subset of SGR chars that can be emitted
+   by pretty-print.cc   */
+
+styled_string::styled_string (style_manager &sm, const char *str)
+: m_chars ()
+{
+  escape_code_parser parser (sm, m_chars);
+
+  /* We don't actually want the display widths here, but
+     it's an easy way to decode UTF-8.  */
+  cpp_char_column_policy policy (8, cpp_wcwidth);
+  cpp_display_width_computation dw (str, strlen (str), policy);
+  while (!dw.done ())
+    {
+      cpp_decoded_char decoded_char;
+      dw.process_next_codepoint (&decoded_char);
+
+      if (!decoded_char.m_valid_ch)
+	/* Skip bytes that aren't valid UTF-8.  */
+	continue;
+
+      /* Decode SGR formatting.  */
+      cppchar_t ch = decoded_char.m_ch;
+      parser.on_char (ch);
+    }
+}
+
+styled_string::styled_string (cppchar_t cppchar, bool emoji)
+{
+  m_chars.push_back (styled_unichar (cppchar, emoji, style::id_plain));
+}
+
+styled_string
+styled_string::from_fmt_va (style_manager &sm,
+			    printer_fn format_decoder,
+			    const char *fmt,
+			    va_list *args)
+{
+  text_info text;
+  text.err_no = errno;
+  text.args_ptr = args;
+  text.format_spec = fmt;
+  pretty_printer pp;
+  pp_show_color (&pp) = true;
+  pp.url_format = URL_FORMAT_DEFAULT;
+  pp_format_decoder (&pp) = format_decoder;
+  pp_format (&pp, &text);
+  pp_output_formatted_text (&pp);
+  styled_string result (sm, pp_formatted_text (&pp));
+  return result;
+}
+
+styled_string
+styled_string::from_fmt (style_manager &sm,
+			 printer_fn format_decoder,
+			 const char *fmt, ...)
+{
+  va_list ap;
+  va_start (ap, fmt);
+  styled_string result = from_fmt_va (sm, format_decoder, fmt, &ap);
+  va_end (ap);
+  return result;
+}
+
+int
+styled_string::calc_canvas_width () const
+{
+  int result = 0;
+  for (auto ch : m_chars)
+    result += ch.get_canvas_width ();
+  return result;
+}
+
+void
+styled_string::append (const styled_string &suffix)
+{
+  m_chars.insert<std::vector<styled_unichar>::const_iterator> (m_chars.end (),
+							       suffix.begin (),
+							       suffix.end ());
+}
+
+void
+styled_string::set_url (style_manager &sm, const char *url)
+{
+  for (auto& ch : m_chars)
+    {
+      const style &existing_style = sm.get_style (ch.get_style_id ());
+      style with_url (existing_style);
+      with_url.set_style_url (url);
+      ch.m_style_id = sm.get_or_create_id (with_url);
+    }
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+static void
+test_combining_chars ()
+{
+  /* This really ought to be in libcpp, but we don't have
+     selftests there.  */
+  ASSERT_FALSE (cpp_is_combining_char (0));
+  ASSERT_FALSE (cpp_is_combining_char ('a'));
+
+  /* COMBINING BREVE (U+0306).  */
+  ASSERT_TRUE (cpp_is_combining_char (0x0306));
+
+  /* U+5B57 CJK UNIFIED IDEOGRAPH-5B57.  */
+  ASSERT_FALSE (cpp_is_combining_char (0x5B57));
+
+  /* U+FE0F VARIATION SELECTOR-16.  */
+  ASSERT_FALSE (cpp_is_combining_char (0xFE0F));
+}
+
+static void
+test_empty ()
+{
+  style_manager sm;
+  styled_string s (sm, "");
+  ASSERT_EQ (s.size (), 0);
+  ASSERT_EQ (s.calc_canvas_width (), 0);
+}
+
+/* Test of a pure ASCII string with no escape codes.  */
+
+static void
+test_simple ()
+{
+  const char *c_str = "hello world!";
+  style_manager sm;
+  styled_string s (sm, c_str);
+  ASSERT_EQ (s.size (), strlen (c_str));
+  ASSERT_EQ (s.calc_canvas_width (), (int)strlen (c_str));
+  for (size_t i = 0; i < strlen (c_str); i++)
+    {
+      ASSERT_EQ (s[i].get_code (), (cppchar_t)c_str[i]);
+      ASSERT_EQ (s[i].get_style_id (), 0);
+    }
+}
+
+/* Test of decoding UTF-8.  */
+
+static void
+test_pi_from_utf8 ()
+{
+  /* U+03C0 "GREEK SMALL LETTER PI".  */
+  const char * const pi_utf8 = "\xCF\x80";
+
+  style_manager sm;
+  styled_string s (sm, pi_utf8);
+  ASSERT_EQ (s.size (), 1);
+  ASSERT_EQ (s.calc_canvas_width (), 1);
+  ASSERT_EQ (s[0].get_code (), 0x03c0);
+  ASSERT_EQ (s[0].emoji_variant_p (), false);
+  ASSERT_EQ (s[0].double_width_p (), false);
+  ASSERT_EQ (s[0].get_style_id (), 0);
+}
+
+/* Test of double-width character.  */
+
+static void
+test_emoji_from_utf8 ()
+{
+  /* U+1F642 "SLIGHTLY SMILING FACE".  */
+  const char * const emoji_utf8 = "\xF0\x9F\x99\x82";
+
+  style_manager sm;
+  styled_string s (sm, emoji_utf8);
+  ASSERT_EQ (s.size (), 1);
+  ASSERT_EQ (s.calc_canvas_width (), 2);
+  ASSERT_EQ (s[0].get_code (), 0x1f642);
+  ASSERT_EQ (s[0].double_width_p (), true);
+  ASSERT_EQ (s[0].get_style_id (), 0);
+}
+
+/* Test of handling U+FE0F VARIATION SELECTOR-16 to select the emoji
+   variation for the previous character.  */
+
+static void
+test_emoji_variant_from_utf8 ()
+{
+  const char * const emoji_utf8
+    = (/* U+26A0 WARNING SIGN.  */
+       "\xE2\x9A\xA0"
+       /* U+FE0F VARIATION SELECTOR-16 (emoji variation selector).  */
+       "\xEF\xB8\x8F");
+
+  style_manager sm;
+  styled_string s (sm, emoji_utf8);
+  ASSERT_EQ (s.size (), 1);
+  ASSERT_EQ (s.calc_canvas_width (), 1);
+  ASSERT_EQ (s[0].get_code (), 0x26a0);
+  ASSERT_EQ (s[0].emoji_variant_p (), true);
+  ASSERT_EQ (s[0].double_width_p (), false);
+  ASSERT_EQ (s[0].get_style_id (), 0);
+}
+
+static void
+test_emoji_from_codepoint ()
+{
+  styled_string s ((cppchar_t)0x1f642);
+  ASSERT_EQ (s.size (), 1);
+  ASSERT_EQ (s.calc_canvas_width (), 2);
+  ASSERT_EQ (s[0].get_code (), 0x1f642);
+  ASSERT_EQ (s[0].double_width_p (), true);
+  ASSERT_EQ (s[0].get_style_id (), 0);
+}
+
+static void
+test_from_mixed_width_utf8 ()
+{
+  /* This UTF-8 string literal is of the form
+     before mojibake after
+   where the Japanese word "mojibake" is written as the following
+   four unicode code points:
+     U+6587 CJK UNIFIED IDEOGRAPH-6587
+     U+5B57 CJK UNIFIED IDEOGRAPH-5B57
+     U+5316 CJK UNIFIED IDEOGRAPH-5316
+     U+3051 HIRAGANA LETTER KE.
+   Each of these is 3 bytes wide when encoded in UTF-8, whereas the
+   "before" and "after" are 1 byte per unicode character.  */
+  const char * const mixed_width_utf8
+    = ("before "
+
+       /* U+6587 CJK UNIFIED IDEOGRAPH-6587
+	  UTF-8: 0xE6 0x96 0x87
+	  C octal escaped UTF-8: \346\226\207.  */
+       "\346\226\207"
+
+       /* U+5B57 CJK UNIFIED IDEOGRAPH-5B57
+	  UTF-8: 0xE5 0xAD 0x97
+	  C octal escaped UTF-8: \345\255\227.  */
+       "\345\255\227"
+
+       /* U+5316 CJK UNIFIED IDEOGRAPH-5316
+	  UTF-8: 0xE5 0x8C 0x96
+	  C octal escaped UTF-8: \345\214\226.  */
+       "\345\214\226"
+
+       /* U+3051 HIRAGANA LETTER KE
+	  UTF-8: 0xE3 0x81 0x91
+	  C octal escaped UTF-8: \343\201\221.  */
+       "\343\201\221"
+
+       " after");
+
+  style_manager sm;
+  styled_string s (sm, mixed_width_utf8);
+  ASSERT_EQ (s.size (), 6 + 1 + 4 + 1 + 5);
+  ASSERT_EQ (sm.get_num_styles (), 1);
+
+  // We expect the Japanese characters to be double width.
+  ASSERT_EQ (s.calc_canvas_width (), 6 + 1 + (2 * 4) + 1 + 5);
+
+  ASSERT_EQ (s[0].get_code (), 'b');
+  ASSERT_EQ (s[0].double_width_p (), false);
+  ASSERT_EQ (s[1].get_code (), 'e');
+  ASSERT_EQ (s[2].get_code (), 'f');
+  ASSERT_EQ (s[3].get_code (), 'o');
+  ASSERT_EQ (s[4].get_code (), 'r');
+  ASSERT_EQ (s[5].get_code (), 'e');
+  ASSERT_EQ (s[6].get_code (), ' ');
+  ASSERT_EQ (s[7].get_code (), 0x6587);
+  ASSERT_EQ (s[7].double_width_p (), true);
+  ASSERT_EQ (s[8].get_code (), 0x5B57);
+  ASSERT_EQ (s[9].get_code (), 0x5316);
+  ASSERT_EQ (s[10].get_code (), 0x3051);
+  ASSERT_EQ (s[11].get_code (), ' ');
+  ASSERT_EQ (s[12].get_code (), 'a');
+  ASSERT_EQ (s[13].get_code (), 'f');
+  ASSERT_EQ (s[14].get_code (), 't');
+  ASSERT_EQ (s[15].get_code (), 'e');
+  ASSERT_EQ (s[16].get_code (), 'r');
+
+  ASSERT_EQ (s[0].get_style_id (), 0);
+}
+
+static void
+assert_style_urleq (const location &loc,
+		    const style &s,
+		    const char *expected_str)
+{
+  ASSERT_EQ_AT (loc, s.m_url.size (), strlen (expected_str));
+  for (size_t i = 0; i < s.m_url.size (); i++)
+    ASSERT_EQ_AT (loc, s.m_url[i], (cppchar_t)expected_str[i]);
+}
+
+#define ASSERT_STYLE_URLEQ(STYLE, EXPECTED_STR) \
+  assert_style_urleq ((SELFTEST_LOCATION), (STYLE), (EXPECTED_STR))
+
+static void
+test_url ()
+{
+  // URL_FORMAT_ST
+  {
+    style_manager sm;
+    styled_string s
+      (sm, "\33]8;;http://example.com\33\\This is a link\33]8;;\33\\");
+    const char *expected = "This is a link";
+    ASSERT_EQ (s.size (), strlen (expected));
+    ASSERT_EQ (s.calc_canvas_width (), (int)strlen (expected));
+    ASSERT_EQ (sm.get_num_styles (), 2);
+    for (size_t i = 0; i < strlen (expected); i++)
+      {
+	ASSERT_EQ (s[i].get_code (), (cppchar_t)expected[i]);
+	ASSERT_EQ (s[i].get_style_id (), 1);
+      }
+    ASSERT_STYLE_URLEQ (sm.get_style (1), "http://example.com");
+  }
+
+  // URL_FORMAT_BEL
+  {
+    style_manager sm;
+    styled_string s
+      (sm, "\33]8;;http://example.com\aThis is a link\33]8;;\a");
+    const char *expected = "This is a link";
+    ASSERT_EQ (s.size (), strlen (expected));
+    ASSERT_EQ (s.calc_canvas_width (), (int)strlen (expected));
+    ASSERT_EQ (sm.get_num_styles (), 2);
+    for (size_t i = 0; i < strlen (expected); i++)
+      {
+	ASSERT_EQ (s[i].get_code (), (cppchar_t)expected[i]);
+	ASSERT_EQ (s[i].get_style_id (), 1);
+      }
+    ASSERT_STYLE_URLEQ (sm.get_style (1), "http://example.com");
+  }
+}
+
+static void
+test_from_fmt ()
+{
+  style_manager sm;
+  styled_string s (styled_string::from_fmt (sm, NULL, "%%i: %i", 42));
+  ASSERT_EQ (s[0].get_code (), '%');
+  ASSERT_EQ (s[1].get_code (), 'i');
+  ASSERT_EQ (s[2].get_code (), ':');
+  ASSERT_EQ (s[3].get_code (), ' ');
+  ASSERT_EQ (s[4].get_code (), '4');
+  ASSERT_EQ (s[5].get_code (), '2');
+  ASSERT_EQ (s.size (), 6);
+  ASSERT_EQ (s.calc_canvas_width (), 6);
+}
+
+static void
+test_from_fmt_qs ()
+{
+  auto_fix_quotes fix_quotes;
+  open_quote = "\xe2\x80\x98";
+  close_quote = "\xe2\x80\x99";
+
+  style_manager sm;
+  styled_string s (styled_string::from_fmt (sm, NULL, "%qs", "msg"));
+  ASSERT_EQ (sm.get_num_styles (), 2);
+  ASSERT_EQ (s[0].get_code (), 0x2018);
+  ASSERT_EQ (s[0].get_style_id (), 0);
+  ASSERT_EQ (s[1].get_code (), 'm');
+  ASSERT_EQ (s[1].get_style_id (), 1);
+  ASSERT_EQ (s[2].get_code (), 's');
+  ASSERT_EQ (s[2].get_style_id (), 1);
+  ASSERT_EQ (s[3].get_code (), 'g');
+  ASSERT_EQ (s[3].get_style_id (), 1);
+  ASSERT_EQ (s[4].get_code (), 0x2019);
+  ASSERT_EQ (s[4].get_style_id (), 0);
+  ASSERT_EQ (s.size (), 5);
+}
+
+// Test of parsing SGR codes.
+
+static void
+test_from_str_with_bold ()
+{
+  style_manager sm;
+  /* This is the result of pp_printf (pp, "%qs", "foo")
+     with auto_fix_quotes.  */
+  styled_string s (sm, "`\33[01m\33[Kfoo\33[m\33[K'");
+  ASSERT_EQ (s[0].get_code (), '`');
+  ASSERT_EQ (s[0].get_style_id (), 0);
+  ASSERT_EQ (s[1].get_code (), 'f');
+  ASSERT_EQ (s[1].get_style_id (), 1);
+  ASSERT_EQ (s[2].get_code (), 'o');
+  ASSERT_EQ (s[2].get_style_id (), 1);
+  ASSERT_EQ (s[3].get_code (), 'o');
+  ASSERT_EQ (s[3].get_style_id (), 1);
+  ASSERT_EQ (s[4].get_code (), '\'');
+  ASSERT_EQ (s[4].get_style_id (), 0);
+  ASSERT_EQ (s.size (), 5);
+  ASSERT_TRUE (sm.get_style (1).m_bold);
+}
+
+static void
+test_from_str_with_underscore ()
+{
+  style_manager sm;
+  styled_string s (sm, "\33[04m\33[KA");
+  ASSERT_EQ (s[0].get_code (), 'A');
+  ASSERT_EQ (s[0].get_style_id (), 1);
+  ASSERT_TRUE (sm.get_style (1).m_underscore);
+}
+
+static void
+test_from_str_with_blink ()
+{
+  style_manager sm;
+  styled_string s (sm, "\33[05m\33[KA");
+  ASSERT_EQ (s[0].get_code (), 'A');
+  ASSERT_EQ (s[0].get_style_id (), 1);
+  ASSERT_TRUE (sm.get_style (1).m_blink);
+}
+
+// Test of parsing SGR codes.
+
+static void
+test_from_str_with_color ()
+{
+  style_manager sm;
+
+  styled_string s (sm,
+		   ("0"
+		    SGR_SEQ (COLOR_FG_RED)
+		    "R"
+		    SGR_RESET
+		    "2"
+		    SGR_SEQ (COLOR_FG_GREEN)
+		    "G"
+		    SGR_RESET
+		    "4"));
+  ASSERT_EQ (s.size (), 5);
+  ASSERT_EQ (sm.get_num_styles (), 3);
+  ASSERT_EQ (s[0].get_code (), '0');
+  ASSERT_EQ (s[0].get_style_id (), 0);
+  ASSERT_EQ (s[1].get_code (), 'R');
+  ASSERT_EQ (s[1].get_style_id (), 1);
+  ASSERT_EQ (s[2].get_code (), '2');
+  ASSERT_EQ (s[2].get_style_id (), 0);
+  ASSERT_EQ (s[3].get_code (), 'G');
+  ASSERT_EQ (s[3].get_style_id (), 2);
+  ASSERT_EQ (s[4].get_code (), '4');
+  ASSERT_EQ (s[4].get_style_id (), 0);
+  ASSERT_EQ (sm.get_style (1).m_fg_color, style::named_color::RED);
+  ASSERT_EQ (sm.get_style (2).m_fg_color, style::named_color::GREEN);
+}
+
+static void
+test_from_str_with_named_color ()
+{
+  style_manager sm;
+  styled_string s (sm,
+		   ("F"
+		    SGR_SEQ (COLOR_FG_BLACK) "F"
+		    SGR_SEQ (COLOR_FG_RED) "F"
+		    SGR_SEQ (COLOR_FG_GREEN) "F"
+		    SGR_SEQ (COLOR_FG_YELLOW) "F"
+		    SGR_SEQ (COLOR_FG_BLUE) "F"
+		    SGR_SEQ (COLOR_FG_MAGENTA) "F"
+		    SGR_SEQ (COLOR_FG_CYAN) "F"
+		    SGR_SEQ (COLOR_FG_WHITE) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_BLACK) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_RED) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_GREEN) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_YELLOW) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_BLUE) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_MAGENTA) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_CYAN) "F"
+		    SGR_SEQ (COLOR_FG_BRIGHT_WHITE) "F"
+		    SGR_SEQ (COLOR_BG_BLACK) "B"
+		    SGR_SEQ (COLOR_BG_RED) "B"
+		    SGR_SEQ (COLOR_BG_GREEN) "B"
+		    SGR_SEQ (COLOR_BG_YELLOW) "B"
+		    SGR_SEQ (COLOR_BG_BLUE) "B"
+		    SGR_SEQ (COLOR_BG_MAGENTA) "B"
+		    SGR_SEQ (COLOR_BG_CYAN) "B"
+		    SGR_SEQ (COLOR_BG_WHITE) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_BLACK) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_RED) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_GREEN) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_YELLOW) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_BLUE) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_MAGENTA) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_CYAN) "B"
+		    SGR_SEQ (COLOR_BG_BRIGHT_WHITE) "B"));
+  ASSERT_EQ (s.size (), 33);
+  for (size_t i = 0; i < s.size (); i++)
+    ASSERT_EQ (s[i].get_style_id (), i);
+  for (size_t i = 0; i < 17; i++)
+    ASSERT_EQ (s[i].get_code (), 'F');
+  for (size_t i = 17; i < 33; i++)
+    ASSERT_EQ (s[i].get_code (), 'B');
+}
+
+static void
+test_from_str_with_8_bit_color ()
+{
+  {
+    style_manager sm;
+    styled_string s (sm,
+		     ("^[[38;5;232m^[[KF"));
+    ASSERT_EQ (s.size (), 1);
+    ASSERT_EQ (s[0].get_code (), 'F');
+    ASSERT_EQ (s[0].get_style_id (), 1);
+    ASSERT_EQ (sm.get_style (1).m_fg_color, style::color (232));
+  }
+  {
+    style_manager sm;
+    styled_string s (sm,
+		     ("^[[48;5;231m^[[KB"));
+    ASSERT_EQ (s.size (), 1);
+    ASSERT_EQ (s[0].get_code (), 'B');
+    ASSERT_EQ (s[0].get_style_id (), 1);
+    ASSERT_EQ (sm.get_style (1).m_bg_color, style::color (231));
+  }
+}
+
+static void
+test_from_str_with_24_bit_color ()
+{
+  {
+    style_manager sm;
+    styled_string s (sm,
+		     ("^[[38;2;243;250;242m^[[KF"));
+    ASSERT_EQ (s.size (), 1);
+    ASSERT_EQ (s[0].get_code (), 'F');
+    ASSERT_EQ (s[0].get_style_id (), 1);
+    ASSERT_EQ (sm.get_style (1).m_fg_color, style::color (243, 250, 242));
+  }
+  {
+    style_manager sm;
+    styled_string s (sm,
+		     ("^[[48;2;253;247;231m^[[KB"));
+    ASSERT_EQ (s.size (), 1);
+    ASSERT_EQ (s[0].get_code (), 'B');
+    ASSERT_EQ (s[0].get_style_id (), 1);
+    ASSERT_EQ (sm.get_style (1).m_bg_color, style::color (253, 247, 231));
+  }
+}
+
+static void
+test_from_str_combining_characters ()
+{
+  style_manager sm;
+  styled_string s (sm,
+		   /* CYRILLIC CAPITAL LETTER U (U+0423).  */
+		   "\xD0\xA3"
+		   /* COMBINING BREVE (U+0306).  */
+		   "\xCC\x86");
+  ASSERT_EQ (s.size (), 1);
+  ASSERT_EQ (s[0].get_code (), 0x423);
+  ASSERT_EQ (s[0].get_combining_chars ().size (), 1);
+  ASSERT_EQ (s[0].get_combining_chars ()[0], 0x306);
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_styled_string_cc_tests ()
+{
+  test_combining_chars ();
+  test_empty ();
+  test_simple ();
+  test_pi_from_utf8 ();
+  test_emoji_from_utf8 ();
+  test_emoji_variant_from_utf8 ();
+  test_emoji_from_codepoint ();
+  test_from_mixed_width_utf8 ();
+  test_url ();
+  test_from_fmt ();
+  test_from_fmt_qs ();
+  test_from_str_with_bold ();
+  test_from_str_with_underscore ();
+  test_from_str_with_blink ();
+  test_from_str_with_color ();
+  test_from_str_with_named_color ();
+  test_from_str_with_8_bit_color ();
+  test_from_str_with_24_bit_color ();
+  test_from_str_combining_characters ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/table.cc b/gcc/text-art/table.cc
new file mode 100644
index 00000000000..42cc4228ea6
--- /dev/null
+++ b/gcc/text-art/table.cc
@@ -0,0 +1,1272 @@
+/* Support for tabular/grid-based content.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_MEMORY
+#include "system.h"
+#include "coretypes.h"
+#include "make-unique.h"
+#include "pretty-print.h"
+#include "diagnostic.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/table.h"
+
+using namespace text_art;
+
+/* class text_art::table_cell_content.  */
+
+table_cell_content::table_cell_content (styled_string &&s)
+: m_str (std::move (s)),
+  /* We assume here that the content occupies a single canvas row.  */
+  m_size (m_str.calc_canvas_width (), 1)
+{
+}
+
+void
+table_cell_content::paint_to_canvas (canvas &canvas,
+				     canvas::coord_t top_left) const
+{
+  canvas.paint_text (top_left, m_str);
+}
+
+/* struct text_art::table_dimension_sizes.  */
+
+table_dimension_sizes::table_dimension_sizes (unsigned num)
+: m_requirements (num, 0)
+{
+}
+
+/* class text_art::table::cell_placement.  */
+
+void
+table::cell_placement::paint_cell_contents_to_canvas(canvas &canvas,
+						     canvas::coord_t offset,
+						     const table_geometry &tg) const
+{
+  const canvas::size_t req_canvas_size = get_min_canvas_size ();
+  const canvas::size_t alloc_canvas_size = tg.get_canvas_size (m_rect);
+  gcc_assert (req_canvas_size.w <= alloc_canvas_size.w);
+  gcc_assert (req_canvas_size.h <= alloc_canvas_size.h);
+  const int x_padding = alloc_canvas_size.w - req_canvas_size.w;
+  const int y_padding = alloc_canvas_size.h - req_canvas_size.h;
+  const table::coord_t table_top_left = m_rect.m_top_left;
+  const canvas::coord_t canvas_top_left = tg.table_to_canvas (table_top_left);
+
+  gcc_assert (x_padding >= 0);
+  int x_align_offset;
+  switch (m_x_align)
+    {
+    default:
+      gcc_unreachable ();
+    case x_align::LEFT:
+      x_align_offset = 0;
+      break;
+    case x_align::CENTER:
+      x_align_offset = x_padding / 2;
+      break;
+    case x_align::RIGHT:
+      x_align_offset = x_padding;
+      break;
+    }
+
+  gcc_assert (y_padding >= 0);
+  int y_align_offset;
+  switch (m_y_align)
+    {
+    default:
+      gcc_unreachable ();
+    case y_align::TOP:
+      y_align_offset = 0;
+      break;
+    case y_align::CENTER:
+      y_align_offset = y_padding / 2;
+      break;
+    case y_align::BOTTOM:
+      y_align_offset = y_padding;
+      break;
+    }
+  const canvas::coord_t content_rel_coord
+    (canvas_top_left.x + 1 + x_align_offset,
+     canvas_top_left.y + 1 + y_align_offset);
+  m_content.paint_to_canvas (canvas, offset + content_rel_coord);
+}
+
+/* class text_art::table.  */
+
+
+table::table (size_t size)
+: m_size (size),
+  m_placements (),
+  m_occupancy (size)
+{
+  m_occupancy.fill (-1);
+}
+
+void
+table::set_cell (coord_t coord,
+		 table_cell_content &&content,
+		 enum x_align x_align,
+		 enum y_align y_align)
+{
+  set_cell_span (rect_t (coord, table::size_t (1, 1)),
+		 std::move (content), x_align, y_align);
+}
+
+void
+table::set_cell_span (rect_t span,
+		      table_cell_content &&content,
+		      enum x_align x_align,
+		      enum y_align y_align)
+{
+  gcc_assert (span.m_size.w > 0);
+  gcc_assert (span.m_size.h > 0);
+  int placement_idx = m_placements.size ();
+  m_placements.emplace_back (cell_placement (span, std::move (content),
+					     x_align, y_align));
+  for (int y = span.get_min_y (); y < span.get_next_y (); y++)
+    for (int x = span.get_min_x (); x < span.get_next_x (); x++)
+      {
+	gcc_assert (m_occupancy.get (coord_t (x, y)) == -1);
+	m_occupancy.set (coord_t (x, y), placement_idx);
+      }
+}
+
+canvas
+table::to_canvas (const theme &theme, const style_manager &sm) const
+{
+  table_dimension_sizes col_widths (m_size.w);
+  table_dimension_sizes row_heights (m_size.h);
+  table_cell_sizes cell_sizes (col_widths, row_heights);
+  cell_sizes.pass_1 (*this);
+  cell_sizes.pass_2 (*this);
+  table_geometry tg (*this, cell_sizes);
+  canvas canvas (tg.get_canvas_size (), sm);
+  paint_to_canvas (canvas, canvas::coord_t (0, 0), tg, theme);
+  return canvas;
+}
+
+void
+table::paint_to_canvas (canvas &canvas,
+			canvas::coord_t offset,
+			const table_geometry &tg,
+			const theme &theme) const
+{
+  canvas.fill (canvas::rect_t (offset, tg.get_canvas_size ()),
+	       styled_unichar (' '));
+  paint_cell_borders_to_canvas (canvas, offset, tg, theme);
+  paint_cell_contents_to_canvas (canvas, offset, tg);
+}
+
+/* Print this table to stderr.  */
+
+DEBUG_FUNCTION void
+table::debug () const
+{
+  /* Use a temporary style manager.
+     Styles in the table will be meaningless, so
+     print the canvas with styling disabled.  */
+  style_manager sm;
+  canvas canvas (to_canvas (unicode_theme (), sm));
+  canvas.debug (false);
+}
+
+const table::cell_placement *
+table::get_placement_at (coord_t coord) const
+{
+  const int placement_idx = m_occupancy.get (coord);
+  if (placement_idx == -1)
+    return nullptr;
+  return &m_placements[placement_idx];
+}
+
+int
+table::get_occupancy_safe (coord_t coord) const
+{
+  if (coord.x < 0)
+    return -1;
+  if (coord.x >= m_size.w)
+    return -1;
+  if (coord.y < 0)
+    return -1;
+  if (coord.y >= m_size.h)
+    return -1;
+  return m_occupancy.get (coord);
+}
+
+/* Determine if the "?" edges need borders for table cell D
+   in the following, for the directions relative to "X", based
+   on whether each of table cell boundaries AB, CD, AC, and BD
+   are boundaries between cell spans:
+
+   #            up?
+   #      +-----+-----+
+   #      |           |
+   #      |     ?     |
+   #      |  A  ?  B  |
+   #      |     ?     |
+   #      |           |
+   # left?+ ??? X ??? + right?
+   #      |           |
+   #      |     ?     |
+   #      |  C  ?  D  |
+   #      |     ?     |
+   #      |           |
+   #      +-----+-----+
+   #          down?
+*/
+
+directions
+table::get_connections (int table_x, int table_y) const
+{
+  int cell_a = get_occupancy_safe (coord_t (table_x - 1, table_y - 1));
+  int cell_b = get_occupancy_safe (coord_t (table_x, table_y - 1));
+  int cell_c = get_occupancy_safe (coord_t (table_x - 1, table_y));
+  int cell_d = get_occupancy_safe (coord_t (table_x, table_y));
+  const bool up = (cell_a != cell_b);
+  const bool down = (cell_c != cell_d);
+  const bool left = (cell_a != cell_c);
+  const bool right = (cell_b != cell_d);
+  return directions (up, down, left, right);
+}
+
+/* Paint the grid lines.
+
+   Consider painting
+   - a grid of cells,
+   - plus a right-hand border
+   - and a bottom border
+
+   Then we need to paint to the canvas like this:
+
+   #         PER-TABLE-COLUMN     R BORDER
+   #      +-------------------+   +-----+
+   #
+   #             TABLE CELL WIDTH (in canvas units)
+   #            +-------------+
+   #      .     .     . .     .   .     .
+   #   ...+-----+-----+.+-----+...+-----+ +
+   #      |  U  |     |.|     |   |  U  | |
+   #      |  U  |     |.|     |   |  U  | |
+   #      |LL+RR|RRRRR|.|RRRRR|   |LL+  | |
+   #      |  D  |     |.|     |   |  D  | |
+   #      |  D  |     |.|     |   |  D  | |
+   #   ...+-----+-----+.+-----+...+-----+ |
+   #      .....................   ......  +-- PER-TABLE-ROW
+   #   ...+-----+-----+.+-----+...+-----+ | +
+   #      |  D  |     |.|     |   |  D  | | |
+   #      |  D  |     |.|     |   |  D  | | |
+   #      |  D  |     |.|     |   |  D  | | +---- TABLE CELL HEIGHT (in canvas units)
+   #      |  D  |     |.|     |   |  D  | | |
+   #      |  D  |     |.|     |   |  D  | | |
+   #   ...+-----+-----+.+-----+...+-----+ + +
+   #      .     .     .     .   .     .
+   #   ...+-----+-----+.+-----+...+-----+  +
+   #      |  D  |     |.|     |   |  U  |  |
+   #      |  D  |     |.|     |   |  U  |  |
+   #      |LL+RR|RRRRR|.|RRRRR|   |LL+  |  | BOTTOM BORDER
+   #      |     |     |.|     |   |     |  |
+   #      |     |     |.|     |   |     |  |
+   #   ...+-----+-----+.+-----+...+-----+  +
+
+   where each:
+
+   #    +-----+
+   #    |     |
+   #    |     |
+   #    |     |
+   #    |     |
+   #    |     |
+   #    +-----+
+
+   is a canvas cell, and the U, L, R, D express the connections
+   that are present with neighboring table cells.  These affect
+   the kinds of borders that we draw for a particular table cell.  */
+
+void
+table::paint_cell_borders_to_canvas (canvas &canvas,
+				     canvas::coord_t offset,
+				     const table_geometry &tg,
+				     const theme &theme) const
+{
+  /* The per-table-cell left and top borders are either drawn or not,
+     but if they are, they aren't affected by per-table-cell connections.  */
+  const canvas::cell_t left_border
+    = theme.get_line_art (directions (true, /* up */
+				      true, /* down */
+				      false, /* left */
+				      false /* right */));
+  const canvas::cell_t top_border
+    = theme.get_line_art (directions (false, /* up */
+				      false, /* down */
+				      true, /* left */
+				      true)); /* right */
+  for (int table_y = 0; table_y < m_size.h; table_y++)
+    {
+      const int canvas_y = tg.table_y_to_canvas_y (table_y);
+      for (int table_x = 0; table_x < m_size.w; table_x++)
+	{
+	  canvas::coord_t canvas_top_left
+	    = tg.table_to_canvas(table::coord_t (table_x, table_y));
+
+	  const directions c (get_connections (table_x, table_y));
+
+	  /* Paint top-left corner of border, if any.  */
+	  canvas.paint (offset + canvas_top_left,
+			theme.get_line_art (c));
+
+	  /* Paint remainder of left border of cell, if any.
+	     We assume here that the content occupies a single canvas row.  */
+	  if (c.m_down)
+	    canvas.paint (offset + canvas::coord_t (canvas_top_left.x,
+						    canvas_y + 1),
+			  left_border);
+
+	  /* Paint remainder of top border of cell, if any.  */
+	  if (c.m_right)
+	    {
+	      const int col_width = tg.get_col_width (table_x);
+	      for (int x_offset = 0; x_offset < col_width; x_offset++)
+		{
+		  const int canvas_x = canvas_top_left.x + 1 + x_offset;
+		  canvas.paint (offset + canvas::coord_t (canvas_x, canvas_y),
+				top_border);
+		}
+	    }
+	}
+
+      /* Paint right-hand border of row.  */
+      const int table_x = m_size.w;
+      const int canvas_x = tg.table_x_to_canvas_x (table_x);
+      const directions c (get_connections (m_size.w, table_y));
+      canvas.paint(offset + canvas::coord_t (canvas_x, canvas_y),
+		   theme.get_line_art (directions (c.m_up,
+						   c.m_down,
+						   c.m_left,
+						   false))); /* right */
+      /* We assume here that the content occupies a single canvas row.  */
+      canvas.paint(offset + canvas::coord_t (canvas_x, canvas_y + 1),
+		   theme.get_line_art (directions (c.m_down, /* up */
+						   c.m_down, /* down */
+						   false, /* left */
+						   false))); /* right */
+    }
+
+  /* Draw bottom border of table.  */
+  {
+    const int canvas_y = tg.get_canvas_size ().h - 1;
+    for (int table_x = 0; table_x < m_size.w; table_x++)
+      {
+	const directions c (get_connections (table_x, m_size.h));
+	const int left_canvas_x = tg.table_x_to_canvas_x (table_x);
+	canvas.paint (offset + canvas::coord_t (left_canvas_x, canvas_y),
+		      theme.get_line_art (directions (c.m_up,
+						      false, /* down */
+						      c.m_left,
+						      c.m_right)));
+	const int col_width = tg.get_col_width (table_x);
+	for (int x_offset = 0; x_offset < col_width; x_offset++)
+	  {
+	    const int canvas_x = left_canvas_x + 1 + x_offset;
+	    canvas.paint(offset + canvas::coord_t (canvas_x, canvas_y),
+			 theme.get_line_art (directions (false, // up
+							 false, // down
+							 c.m_right, // left
+							 c.m_right))); // right
+	  }
+      }
+
+    /* Bottom-right corner of table.  */
+    const int table_x = m_size.w;
+    const int canvas_x = tg.table_x_to_canvas_x (table_x);
+    const directions c (get_connections (m_size.w, m_size.h));
+    canvas.paint (offset + canvas::coord_t (canvas_x, canvas_y),
+		  theme.get_line_art (directions (c.m_up, // up
+						  false, // down
+						  c.m_left, // left
+						  false))); // right
+  }
+}
+
+void
+table::paint_cell_contents_to_canvas(canvas &canvas,
+				     canvas::coord_t offset,
+				     const table_geometry &tg) const
+{
+  for (auto &placement : m_placements)
+    placement.paint_cell_contents_to_canvas (canvas, offset, tg);
+}
+
+/* class table_cell_sizes.  */
+
+/* Consider 1x1 cells.  */
+
+void
+table_cell_sizes::pass_1 (const table &table)
+{
+  for (auto &placement : table.m_placements)
+    if (placement.one_by_one_p ())
+      {
+	canvas::size_t canvas_size (placement.get_min_canvas_size ());
+	table::coord_t table_coord (placement.m_rect.m_top_left);
+	m_col_widths.require (table_coord.x, canvas_size.w);
+	m_row_heights.require (table_coord.y, canvas_size.h);
+      }
+}
+
+/* Consider cells that span more than one row or column.  */
+
+void
+table_cell_sizes::pass_2 (const table &table)
+{
+  for (auto &placement : table.m_placements)
+    if (!placement.one_by_one_p ())
+      {
+	const canvas::size_t req_canvas_size (placement.get_min_canvas_size ());
+	const canvas::size_t current_canvas_size
+	  = get_canvas_size (placement.m_rect);
+	/* Grow columns as necessary.  */
+	if (req_canvas_size.w > current_canvas_size.w)
+	  {
+	    /* Spread the deficit amongst the columns.  */
+	    int deficit = req_canvas_size.w - current_canvas_size.w;
+	    const int per_col = deficit / placement.m_rect.m_size.w;
+	    for (int table_x = placement.m_rect.get_min_x ();
+		 table_x < placement.m_rect.get_next_x ();
+		 table_x++)
+	    {
+	      m_col_widths.m_requirements[table_x] += per_col;
+	      deficit -= per_col;
+	    }
+	    /* Make sure we allocate all of the deficit.  */
+	    if (deficit > 0)
+	      {
+		const int table_x = placement.m_rect.get_max_x ();
+		m_col_widths.m_requirements[table_x] += deficit;
+	      }
+	  }
+	/* Grow rows as necessary.  */
+	if (req_canvas_size.h > current_canvas_size.h)
+	  {
+	    /* Spread the deficit amongst the rows.  */
+	    int deficit = req_canvas_size.h - current_canvas_size.h;
+	    const int per_row = deficit / placement.m_rect.m_size.h;
+	    for (int table_y = placement.m_rect.get_min_y ();
+		 table_y < placement.m_rect.get_next_y ();
+		 table_y++)
+	    {
+	      m_row_heights.m_requirements[table_y] += per_row;
+	      deficit -= per_row;
+	    }
+	    /* Make sure we allocate all of the deficit.  */
+	    if (deficit > 0)
+	      {
+		const int table_y = placement.m_rect.get_max_y ();
+		m_row_heights.m_requirements[table_y] += deficit;
+	      }
+	  }
+      }
+}
+
+canvas::size_t
+table_cell_sizes::get_canvas_size (const table::rect_t &rect) const
+{
+  canvas::size_t result (0, 0);
+  for (int table_x = rect.get_min_x ();
+       table_x < rect.get_next_x ();
+       table_x ++)
+    result.w += m_col_widths.m_requirements[table_x];
+  for (int table_y = rect.get_min_y ();
+       table_y < rect.get_next_y ();
+       table_y ++)
+    result.h += m_row_heights.m_requirements[table_y];
+  /* Allow space for the borders.  */
+  result.w += rect.m_size.w - 1;
+  result.h += rect.m_size.h - 1;
+  return result;
+}
+
+/* class text_art::table_geometry.  */
+
+table_geometry::table_geometry (const table &table, table_cell_sizes &cell_sizes)
+: m_table (table),
+  m_cell_sizes (cell_sizes),
+  m_canvas_size (canvas::size_t (0, 0)),
+  m_col_start_x (table.get_size ().w),
+  m_row_start_y (table.get_size ().h)
+{
+  recalc_coords ();
+}
+
+void
+table_geometry::recalc_coords ()
+{
+  /* Start canvas column of table cell, including leading border.  */
+  m_col_start_x.clear ();
+  int iter_canvas_x = 0;
+  for (auto w : m_cell_sizes.m_col_widths.m_requirements)
+    {
+      m_col_start_x.push_back (iter_canvas_x);
+      iter_canvas_x += w + 1;
+    }
+
+  /* Start canvas row of table cell, including leading border.  */
+  m_row_start_y.clear ();
+  int iter_canvas_y = 0;
+  for (auto h : m_cell_sizes.m_row_heights.m_requirements)
+    {
+      m_row_start_y.push_back (iter_canvas_y);
+      iter_canvas_y += h + 1;
+    }
+
+  m_canvas_size = canvas::size_t (iter_canvas_x + 1,
+				  iter_canvas_y + 1);
+}
+
+/* Get the TL corner of the table cell at TABLE_COORD
+   in canvas coords (including the border).  */
+
+canvas::coord_t
+table_geometry::table_to_canvas (table::coord_t table_coord) const
+{
+  return canvas::coord_t (table_x_to_canvas_x (table_coord.x),
+			  table_y_to_canvas_y (table_coord.y));
+}
+
+/* Get the left border of the table cell at column TABLE_X
+   in canvas coords (including the border).  */
+
+int
+table_geometry::table_x_to_canvas_x (int table_x) const
+{
+  /* Allow one beyond the end, for the right-hand border of the table.  */
+  if (table_x == m_col_start_x.size ())
+    return m_canvas_size.w - 1;
+  return m_col_start_x[table_x];
+}
+
+/* Get the top border of the table cell at column TABLE_Y
+   in canvas coords (including the border).  */
+
+int
+table_geometry::table_y_to_canvas_y (int table_y) const
+{
+  /* Allow one beyond the end, for the right-hand border of the table.  */
+  if (table_y == m_row_start_y.size ())
+    return m_canvas_size.h - 1;
+  return m_row_start_y[table_y];
+}
+
+/* class text_art::simple_table_geometry.  */
+
+simple_table_geometry::simple_table_geometry (const table &table)
+: m_col_widths (table.get_size ().w),
+  m_row_heights (table.get_size ().h),
+  m_cell_sizes (m_col_widths, m_row_heights),
+  m_tg (table, m_cell_sizes)
+{
+  m_cell_sizes.pass_1 (table);
+  m_cell_sizes.pass_2 (table);
+  m_tg.recalc_coords ();
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+static void
+test_tic_tac_toe ()
+{
+  style_manager sm;
+  table t (table::size_t (3, 3));
+  t.set_cell (table::coord_t (0, 0), styled_string (sm, "X"));
+  t.set_cell (table::coord_t (1, 0), styled_string (sm, ""));
+  t.set_cell (table::coord_t (2, 0), styled_string (sm, ""));
+  t.set_cell (table::coord_t (0, 1), styled_string (sm, "O"));
+  t.set_cell (table::coord_t (1, 1), styled_string (sm, "O"));
+  t.set_cell (table::coord_t (2, 1), styled_string (sm, ""));
+  t.set_cell (table::coord_t (0, 2), styled_string (sm, "X"));
+  t.set_cell (table::coord_t (1, 2), styled_string (sm, ""));
+  t.set_cell (table::coord_t (2, 2), styled_string (sm, "O"));
+
+  {
+    canvas canvas (t.to_canvas (ascii_theme (), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("+-+-+-+\n"
+	"|X| | |\n"
+	"+-+-+-+\n"
+	"|O|O| |\n"
+	"+-+-+-+\n"
+	"|X| |O|\n"
+	"+-+-+-+\n"));
+  }
+
+  {
+    canvas canvas (t.to_canvas (unicode_theme (), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌─┬─┬─┐\n"
+	"│X│ │ │\n"
+	"├─┼─┼─┤\n"
+	"│O│O│ │\n"
+	"├─┼─┼─┤\n"
+	"│X│ │O│\n"
+	"└─┴─┴─┘\n"));
+  }
+}
+
+static table
+make_text_table ()
+{
+  style_manager sm;
+  table t (table::size_t (3, 3));
+  t.set_cell (table::coord_t (0, 0), styled_string (sm, "top left"));
+  t.set_cell (table::coord_t (1, 0), styled_string (sm, "top middle"));
+  t.set_cell (table::coord_t (2, 0), styled_string (sm, "top right"));
+  t.set_cell (table::coord_t (0, 1), styled_string (sm, "middle left"));
+  t.set_cell (table::coord_t (1, 1), styled_string (sm, "middle middle"));
+  t.set_cell (table::coord_t (2, 1), styled_string (sm, "middle right"));
+  t.set_cell (table::coord_t (0, 2), styled_string (sm, "bottom left"));
+  t.set_cell (table::coord_t (1, 2), styled_string (sm, "bottom middle"));
+  t.set_cell (table::coord_t (2, 2), styled_string (sm, "bottom right"));
+  return t;
+}
+
+static void
+test_text_table ()
+{
+  style_manager sm;
+  table table = make_text_table ();
+  {
+    canvas canvas (table.to_canvas (ascii_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("+-----------+-------------+------------+\n"
+	"| top left  | top middle  | top right  |\n"
+	"+-----------+-------------+------------+\n"
+	"|middle left|middle middle|middle right|\n"
+	"+-----------+-------------+------------+\n"
+	"|bottom left|bottom middle|bottom right|\n"
+	"+-----------+-------------+------------+\n"));
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌───────────┬─────────────┬────────────┐\n"
+	"│ top left  │ top middle  │ top right  │\n"
+	"├───────────┼─────────────┼────────────┤\n"
+	"│middle left│middle middle│middle right│\n"
+	"├───────────┼─────────────┼────────────┤\n"
+	"│bottom left│bottom middle│bottom right│\n"
+	"└───────────┴─────────────┴────────────┘\n"));
+  }
+}
+
+static void
+test_offset_table ()
+{
+  style_manager sm;
+  table table = make_text_table ();
+  simple_table_geometry stg (table);
+  const canvas::size_t tcs = stg.m_tg.get_canvas_size();
+  {
+    canvas canvas (canvas::size_t (tcs.w + 5, tcs.h + 5), sm);
+    canvas.debug_fill ();
+    table.paint_to_canvas (canvas, canvas::coord_t (3, 3),
+			   stg.m_tg,
+			   ascii_theme());
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("*********************************************\n"
+	"*********************************************\n"
+	"*********************************************\n"
+	"***+-----------+-------------+------------+**\n"
+	"***| top left  | top middle  | top right  |**\n"
+	"***+-----------+-------------+------------+**\n"
+	"***|middle left|middle middle|middle right|**\n"
+	"***+-----------+-------------+------------+**\n"
+	"***|bottom left|bottom middle|bottom right|**\n"
+	"***+-----------+-------------+------------+**\n"
+	"*********************************************\n"
+	"*********************************************\n"));
+  }
+  {
+    canvas canvas (canvas::size_t (tcs.w + 5, tcs.h + 5), sm);
+    canvas.debug_fill ();
+    table.paint_to_canvas (canvas, canvas::coord_t (3, 3),
+			   stg.m_tg,
+			   unicode_theme());
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("*********************************************\n"
+	"*********************************************\n"
+	"*********************************************\n"
+	"***┌───────────┬─────────────┬────────────┐**\n"
+	"***│ top left  │ top middle  │ top right  │**\n"
+	"***├───────────┼─────────────┼────────────┤**\n"
+	"***│middle left│middle middle│middle right│**\n"
+	"***├───────────┼─────────────┼────────────┤**\n"
+	"***│bottom left│bottom middle│bottom right│**\n"
+	"***└───────────┴─────────────┴────────────┘**\n"
+	"*********************************************\n"
+	"*********************************************\n"));
+  }
+}
+
+#define ASSERT_TABLE_CELL_STREQ(TABLE, TABLE_X, TABLE_Y, EXPECTED_STR)	\
+  SELFTEST_BEGIN_STMT							\
+    table::coord_t coord ((TABLE_X), (TABLE_Y));			\
+    const table::cell_placement *cp = (TABLE).get_placement_at (coord);	\
+    ASSERT_NE (cp, nullptr);						\
+    ASSERT_EQ (cp->get_content (), styled_string (sm, EXPECTED_STR)); \
+  SELFTEST_END_STMT
+
+#define ASSERT_TABLE_NULL_CELL(TABLE, TABLE_X, TABLE_Y)			\
+  SELFTEST_BEGIN_STMT							\
+    table::coord_t coord ((TABLE_X), (TABLE_Y));			\
+    const table::cell_placement *cp = (TABLE).get_placement_at (coord);	\
+    ASSERT_EQ (cp, nullptr);						\
+  SELFTEST_END_STMT
+
+static void
+test_spans ()
+{
+  style_manager sm;
+  table table (table::size_t (3, 3));
+  table.set_cell_span (table::rect_t (table::coord_t (0, 0),
+				      table::size_t (3, 1)),
+		       styled_string (sm, "ABC"));
+  table.set_cell_span (table::rect_t (table::coord_t (0, 1),
+				      table::size_t (2, 1)),
+		       styled_string (sm, "DE"));
+  table.set_cell_span (table::rect_t (table::coord_t (2, 1),
+				      table::size_t (1, 1)),
+		       styled_string (sm, "F"));
+  table.set_cell (table::coord_t (0, 2), styled_string (sm, "G"));
+  table.set_cell (table::coord_t (1, 2), styled_string (sm, "H"));
+  table.set_cell (table::coord_t (2, 2), styled_string (sm, "I"));
+  {
+    canvas canvas (table.to_canvas (ascii_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("+-----+\n"
+	"| ABC |\n"
+	"+---+-+\n"
+	"|DE |F|\n"
+	"+-+-+-+\n"
+	"|G|H|I|\n"
+	"+-+-+-+\n"));
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌─────┐\n"
+	"│ ABC │\n"
+	"├───┬─┤\n"
+	"│DE │F│\n"
+	"├─┬─┼─┤\n"
+	"│G│H│I│\n"
+	"└─┴─┴─┘\n"));
+  }
+}
+
+/* Verify building this 5x5 table with spans:
+     |0|1|2|3|4|
+     +-+-+-+-+-+
+    0|A A A|B|C|0
+     +     +-+ +
+    1|A A A|D|C|1
+     +     +-+-+
+    2|A A A|E|F|2
+     +-+-+-+-+-+
+    3|G G|H|I I|3
+     |   | +-+-+
+    4|G G|H|J J|4
+     +-+-+-+-+-+
+     |0|1|2|3|4|
+*/
+
+static void
+test_spans_2 ()
+{
+  style_manager sm;
+  table table (table::size_t (5, 5));
+  table.set_cell_span (table::rect_t (table::coord_t (0, 0),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "A"));
+  table.set_cell_span (table::rect_t (table::coord_t (3, 0),
+				      table::size_t (1, 1)),
+		       styled_string (sm, "B"));
+  table.set_cell_span (table::rect_t (table::coord_t (4, 0),
+				      table::size_t (1, 2)),
+		       styled_string (sm, "C"));
+  table.set_cell_span (table::rect_t (table::coord_t (3, 1),
+				      table::size_t (1, 1)),
+		       styled_string (sm, "D"));
+  table.set_cell_span (table::rect_t (table::coord_t (3, 2),
+				      table::size_t (1, 1)),
+		       styled_string (sm, "E"));
+  table.set_cell_span (table::rect_t (table::coord_t (4, 2),
+				      table::size_t (1, 1)),
+		       styled_string (sm, "F"));
+  table.set_cell_span (table::rect_t (table::coord_t (0, 3),
+				      table::size_t (2, 2)),
+		       styled_string (sm, "G"));
+  table.set_cell_span (table::rect_t (table::coord_t (2, 3),
+				      table::size_t (1, 2)),
+		       styled_string (sm, "H"));
+  table.set_cell_span (table::rect_t (table::coord_t (3, 3),
+				      table::size_t (2, 1)),
+		       styled_string (sm, "I"));
+  table.set_cell_span (table::rect_t (table::coord_t (3, 4),
+				      table::size_t (2, 1)),
+		       styled_string (sm, "J"));
+
+  /* Check occupancy at each table coordinate.  */
+  ASSERT_TABLE_CELL_STREQ (table, 0, 0, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 0, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 0, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 3, 0, "B");
+  ASSERT_TABLE_CELL_STREQ (table, 4, 0, "C");
+
+  ASSERT_TABLE_CELL_STREQ (table, 0, 1, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 1, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 1, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 3, 1, "D");
+  ASSERT_TABLE_CELL_STREQ (table, 4, 1, "C");
+
+  ASSERT_TABLE_CELL_STREQ (table, 0, 2, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 2, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 2, "A");
+  ASSERT_TABLE_CELL_STREQ (table, 3, 2, "E");
+  ASSERT_TABLE_CELL_STREQ (table, 4, 2, "F");
+
+  ASSERT_TABLE_CELL_STREQ (table, 0, 3, "G");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 3, "G");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 3, "H");
+  ASSERT_TABLE_CELL_STREQ (table, 3, 3, "I");
+  ASSERT_TABLE_CELL_STREQ (table, 4, 3, "I");
+
+  ASSERT_TABLE_CELL_STREQ (table, 0, 4, "G");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 4, "G");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 4, "H");
+  ASSERT_TABLE_CELL_STREQ (table, 3, 4, "J");
+  ASSERT_TABLE_CELL_STREQ (table, 4, 4, "J");
+
+  {
+    canvas canvas (table.to_canvas (ascii_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("+---+-+-+\n"
+	"|   |B| |\n"
+	"|   +-+C|\n"
+	"| A |D| |\n"
+	"|   +-+-+\n"
+	"|   |E|F|\n"
+	"+-+-+-+-+\n"
+	"| | | I |\n"
+	"|G|H+---+\n"
+	"| | | J |\n"
+	"+-+-+---+\n"));
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌───┬─┬─┐\n"
+	"│   │B│ │\n"
+	"│   ├─┤C│\n"
+	"│ A │D│ │\n"
+	"│   ├─┼─┤\n"
+	"│   │E│F│\n"
+	"├─┬─┼─┴─┤\n"
+	"│ │ │ I │\n"
+	"│G│H├───┤\n"
+	"│ │ │ J │\n"
+	"└─┴─┴───┘\n"));
+  }
+}
+
+/* Experiment with adding a 1-table-column gap at the boundary between
+   valid vs invalid for visualizing a buffer overflow.  */
+static void
+test_spans_3 ()
+{
+  const char * const str = "hello world!";
+  const size_t buf_size = 10;
+  const size_t str_size = strlen (str) + 1;
+
+  style_manager sm;
+  table table (table::size_t (str_size + 1, 3));
+
+  table.set_cell_span (table::rect_t (table::coord_t (0, 0),
+				      table::size_t (str_size + 1, 1)),
+		       styled_string (sm, "String literal"));
+
+  for (size_t i = 0; i < str_size; i++)
+    {
+      table::coord_t c (i, 1);
+      if (i >= buf_size)
+	c.x++;
+      if (str[i] == '\0')
+	table.set_cell (c, styled_string (sm, "NUL"));
+      else
+	table.set_cell (c, styled_string ((cppchar_t)str[i]));
+    }
+
+  table.set_cell_span (table::rect_t (table::coord_t (0, 2),
+				      table::size_t (buf_size, 1)),
+		       styled_string::from_fmt (sm,
+						     nullptr,
+						     "'buf' (char[%i])",
+						     (int)buf_size));
+  table.set_cell_span (table::rect_t (table::coord_t (buf_size + 1, 2),
+				      table::size_t (str_size - buf_size, 1)),
+		       styled_string (sm, "overflow"));
+
+  {
+    canvas canvas (table.to_canvas (ascii_theme (), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       "+-----------------------------+\n"
+       "|       String literal        |\n"
+       "+-+-+-+-+-+-+-+-+-+-++-+-+----+\n"
+       "|h|e|l|l|o| |w|o|r|l||d|!|NUL |\n"
+       "+-+-+-+-+-+-+-+-+-+-++-+-+----+\n"
+       "| 'buf' (char[10])  ||overflow|\n"
+       "+-------------------++--------+\n");
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme (), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌─────────────────────────────┐\n"
+	"│       String literal        │\n"
+	"├─┬─┬─┬─┬─┬─┬─┬─┬─┬─┬┬─┬─┬────┤\n"
+	"│h│e│l│l│o│ │w│o│r│l││d│!│NUL │\n"
+	"├─┴─┴─┴─┴─┴─┴─┴─┴─┴─┤├─┴─┴────┤\n"
+	"│ 'buf' (char[10])  ││overflow│\n"
+	"└───────────────────┘└────────┘\n"));
+  }
+}
+
+static void
+test_double_width_chars ()
+{
+  table_cell_content tcc (styled_string ((cppchar_t)0x1f642));
+  ASSERT_EQ (tcc.get_canvas_size ().w, 2);
+  ASSERT_EQ (tcc.get_canvas_size ().h, 1);
+
+  style_manager sm;
+  table table (table::size_t (1, 1));
+  table.set_cell (table::coord_t (0,0),
+		  styled_string ((cppchar_t)0x1f642));
+
+  canvas canvas (table.to_canvas (unicode_theme(), sm));
+  ASSERT_CANVAS_STREQ
+    (canvas, false,
+     // FIXME: are we allowed unicode chars in string literals in our source?
+     ("┌──┐\n"
+      "│🙂│\n"
+      "└──┘\n"));
+}
+
+static void
+test_ipv4_header ()
+{
+  style_manager sm;
+  table table (table::size_t (34, 10));
+  table.set_cell (table::coord_t (0, 0), styled_string (sm, "Offsets"));
+  table.set_cell (table::coord_t (1, 0), styled_string (sm, "Octet"));
+  table.set_cell (table::coord_t (0, 1), styled_string (sm, "Octet"));
+  for (int octet = 0; octet < 4; octet++)
+    table.set_cell_span (table::rect_t (table::coord_t (2 + (octet * 8), 0),
+					table::size_t (8, 1)),
+			 styled_string::from_fmt (sm, nullptr, "%i", octet));
+  table.set_cell (table::coord_t (1, 1), styled_string (sm, "Bit"));
+  for (int bit = 0; bit < 32; bit++)
+    table.set_cell (table::coord_t (bit + 2, 1),
+		    styled_string::from_fmt (sm, nullptr, "%i", bit));
+  for (int word = 0; word < 6; word++)
+    {
+      table.set_cell (table::coord_t (0, word + 2),
+		      styled_string::from_fmt (sm, nullptr, "%i", word * 4));
+      table.set_cell (table::coord_t (1, word + 2),
+		      styled_string::from_fmt (sm, nullptr, "%i", word * 32));
+    }
+
+  table.set_cell (table::coord_t (0, 8), styled_string (sm, "..."));
+  table.set_cell (table::coord_t (1, 8), styled_string (sm, "..."));
+  table.set_cell (table::coord_t (0, 9), styled_string (sm, "56"));
+  table.set_cell (table::coord_t (1, 9), styled_string (sm, "448"));
+
+#define SET_BITS(FIRST, LAST, NAME)					\
+  do {									\
+    const int first = (FIRST);						\
+    const int last = (LAST);						\
+    const char *name = (NAME);						\
+    const int row = first / 32;						\
+    gcc_assert (last / 32 == row);					\
+    table::rect_t rect (table::coord_t ((first % 32) + 2, row + 2),	\
+			table::size_t (last + 1 - first , 1));		\
+    table.set_cell_span (rect, styled_string (sm, name));		\
+  } while (0)
+
+  SET_BITS (0, 3, "Version");
+  SET_BITS (4, 7, "IHL");
+  SET_BITS (8, 13, "DSCP");
+  SET_BITS (14, 15, "ECN");
+  SET_BITS (16, 31, "Total Length");
+
+  SET_BITS (32 +  0, 32 + 15, "Identification");
+  SET_BITS (32 + 16, 32 + 18, "Flags");
+  SET_BITS (32 + 19, 32 + 31, "Fragment Offset");
+
+  SET_BITS (64 +  0, 64 +  7, "Time To Live");
+  SET_BITS (64 +  8, 64 + 15, "Protocol");
+  SET_BITS (64 + 16, 64 + 31, "Header Checksum");
+
+  SET_BITS (96 +  0, 96 + 31, "Source IP Address");
+  SET_BITS (128 +  0, 128 + 31, "Destination IP Address");
+
+  table.set_cell_span(table::rect_t (table::coord_t (2, 7),
+				     table::size_t (32, 3)),
+		      styled_string (sm, "Options"));
+  {
+    canvas canvas (table.to_canvas (ascii_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("+-------+-----+---------------+---------------------+-----------------------+-----------------------+\n"
+	"|Offsets|Octet|       0       |          1          |           2           |           3           |\n"
+	"+-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+\n"
+	"| Octet | Bit |0|1|2|3|4|5|6|7|8|9|10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25|26|27|28|29|30|31|\n"
+	"+-------+-----+-+-+-+-+-+-+-+-+-+-+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+\n"
+	"|   0   |  0  |Version|  IHL  |     DSCP      | ECN |                 Total Length                  |\n"
+	"+-------+-----+-------+-------+---------------+-----+--------+--------------------------------------+\n"
+	"|   4   | 32  |           Identification            | Flags  |           Fragment Offset            |\n"
+	"+-------+-----+---------------+---------------------+--------+--------------------------------------+\n"
+	"|   8   | 64  | Time To Live  |      Protocol       |                Header Checksum                |\n"
+	"+-------+-----+---------------+---------------------+-----------------------------------------------+\n"
+	"|  12   | 96  |                                  Source IP Address                                  |\n"
+	"+-------+-----+-------------------------------------------------------------------------------------+\n"
+	"|  16   | 128 |                               Destination IP Address                                |\n"
+	"+-------+-----+-------------------------------------------------------------------------------------+\n"
+	"|  20   | 160 |                                                                                     |\n"
+	"+-------+-----+                                                                                     |\n"
+	"|  ...  | ... |                                       Options                                       |\n"
+	"+-------+-----+                                                                                     |\n"
+	"|  56   | 448 |                                                                                     |\n"
+	"+-------+-----+-------------------------------------------------------------------------------------+\n"));
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       // FIXME: are we allowed unicode chars in string literals in our source?
+       ("┌───────┬─────┬───────────────┬─────────────────────┬───────────────────────┬───────────────────────┐\n"
+	"│Offsets│Octet│       0       │          1          │           2           │           3           │\n"
+	"├───────┼─────┼─┬─┬─┬─┬─┬─┬─┬─┼─┬─┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┼──┬──┬──┬──┬──┬──┬──┬──┤\n"
+	"│ Octet │ Bit │0│1│2│3│4│5│6│7│8│9│10│11│12│13│14│15│16│17│18│19│20│21│22│23│24│25│26│27│28│29│30│31│\n"
+	"├───────┼─────┼─┴─┴─┴─┼─┴─┴─┴─┼─┴─┴──┴──┴──┴──┼──┴──┼──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┴──┤\n"
+	"│   0   │  0  │Version│  IHL  │     DSCP      │ ECN │                 Total Length                  │\n"
+	"├───────┼─────┼───────┴───────┴───────────────┴─────┼────────┬──────────────────────────────────────┤\n"
+	"│   4   │ 32  │           Identification            │ Flags  │           Fragment Offset            │\n"
+	"├───────┼─────┼───────────────┬─────────────────────┼────────┴──────────────────────────────────────┤\n"
+	"│   8   │ 64  │ Time To Live  │      Protocol       │                Header Checksum                │\n"
+	"├───────┼─────┼───────────────┴─────────────────────┴───────────────────────────────────────────────┤\n"
+	"│  12   │ 96  │                                  Source IP Address                                  │\n"
+	"├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤\n"
+	"│  16   │ 128 │                               Destination IP Address                                │\n"
+	"├───────┼─────┼─────────────────────────────────────────────────────────────────────────────────────┤\n"
+	"│  20   │ 160 │                                                                                     │\n"
+	"├───────┼─────┤                                                                                     │\n"
+	"│  ...  │ ... │                                       Options                                       │\n"
+	"├───────┼─────┤                                                                                     │\n"
+	"│  56   │ 448 │                                                                                     │\n"
+	"└───────┴─────┴─────────────────────────────────────────────────────────────────────────────────────┘\n"));
+  }
+}
+
+static void
+test_missing_cells ()
+{
+  style_manager sm;
+  table table (table::size_t (3, 3));
+  table.set_cell (table::coord_t (1, 0), styled_string (sm, "A"));
+  table.set_cell (table::coord_t (0, 1), styled_string (sm, "B"));
+  table.set_cell (table::coord_t (1, 1), styled_string (sm, "C"));
+  table.set_cell (table::coord_t (2, 1), styled_string (sm, "D"));
+  table.set_cell (table::coord_t (1, 2), styled_string (sm, "E"));
+
+  ASSERT_TABLE_NULL_CELL (table, 0, 0);
+  ASSERT_TABLE_CELL_STREQ (table, 1, 0, "A");
+  ASSERT_TABLE_NULL_CELL (table, 2, 0);
+
+  ASSERT_TABLE_CELL_STREQ (table, 0, 1, "B");
+  ASSERT_TABLE_CELL_STREQ (table, 1, 1, "C");
+  ASSERT_TABLE_CELL_STREQ (table, 2, 1, "D");
+
+  ASSERT_TABLE_NULL_CELL (table, 0, 2);
+  ASSERT_TABLE_CELL_STREQ (table, 1, 2, "E");
+  ASSERT_TABLE_NULL_CELL (table, 2, 2);
+
+  {
+    canvas canvas (table.to_canvas (ascii_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("  +-+\n"
+	"  |A|\n"
+	"+-+-+-+\n"
+	"|B|C|D|\n"
+	"+-+-+-+\n"
+	"  |E|\n"
+	"  +-+\n"));
+  }
+  {
+    canvas canvas (table.to_canvas (unicode_theme(), sm));
+    ASSERT_CANVAS_STREQ
+      (canvas, false,
+       ("  ┌─┐\n"
+	"  │A│\n"
+	"┌─┼─┼─┐\n"
+	"│B│C│D│\n"
+	"└─┼─┼─┘\n"
+	"  │E│\n"
+	"  └─┘\n"));
+  }
+}
+
+static void
+test_add_row ()
+{
+  style_manager sm;
+  table table (table::size_t (3, 0));
+  for (int i = 0; i < 5; i++)
+    {
+      const int y = table.add_row ();
+      for (int x = 0; x < 3; x++)
+	table.set_cell (table::coord_t (x, y),
+			styled_string::from_fmt (sm, nullptr,
+						 "%i, %i", x, y));
+    }
+  canvas canvas (table.to_canvas (ascii_theme(), sm));
+  ASSERT_CANVAS_STREQ
+    (canvas, false,
+     ("+----+----+----+\n"
+      "|0, 0|1, 0|2, 0|\n"
+      "+----+----+----+\n"
+      "|0, 1|1, 1|2, 1|\n"
+      "+----+----+----+\n"
+      "|0, 2|1, 2|2, 2|\n"
+      "+----+----+----+\n"
+      "|0, 3|1, 3|2, 3|\n"
+      "+----+----+----+\n"
+      "|0, 4|1, 4|2, 4|\n"
+      "+----+----+----+\n"));
+}
+
+static void
+test_alignment ()
+{
+  style_manager sm;
+  table table (table::size_t (9, 9));
+  table.set_cell_span (table::rect_t (table::coord_t (0, 0),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "left top"),
+		      x_align::LEFT, y_align::TOP);
+  table.set_cell_span (table::rect_t (table::coord_t (3, 0),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "center top"),
+		       x_align::CENTER, y_align::TOP);
+  table.set_cell_span (table::rect_t (table::coord_t (6, 0),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "right top"),
+		       x_align::RIGHT, y_align::TOP);
+  table.set_cell_span (table::rect_t (table::coord_t (0, 3),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "left center"),
+		       x_align::LEFT, y_align::CENTER);
+  table.set_cell_span (table::rect_t (table::coord_t (3, 3),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "center center"),
+		       x_align::CENTER, y_align::CENTER);
+  table.set_cell_span (table::rect_t (table::coord_t (6, 3),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "right center"),
+		       x_align::RIGHT, y_align::CENTER);
+  table.set_cell_span (table::rect_t (table::coord_t (0, 6),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "left bottom"),
+		       x_align::LEFT, y_align::BOTTOM);
+  table.set_cell_span (table::rect_t (table::coord_t (3, 6),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "center bottom"),
+		       x_align::CENTER, y_align::BOTTOM);
+  table.set_cell_span (table::rect_t (table::coord_t (6, 6),
+				      table::size_t (3, 3)),
+		       styled_string (sm, "right bottom"),
+		       x_align::RIGHT, y_align::BOTTOM);
+
+  canvas canvas (table.to_canvas (ascii_theme(), sm));
+  ASSERT_CANVAS_STREQ
+    (canvas, false,
+     ("+-----------+-------------+------------+\n"
+      "|left top   | center top  |   right top|\n"
+      "|           |             |            |\n"
+      "+-----------+-------------+------------+\n"
+      "|left center|center center|right center|\n"
+      "|           |             |            |\n"
+      "+-----------+-------------+------------+\n"
+      "|           |             |            |\n"
+      "|left bottom|center bottom|right bottom|\n"
+      "+-----------+-------------+------------+\n"));
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_table_cc_tests ()
+{
+  test_tic_tac_toe ();
+  test_text_table ();
+  test_offset_table ();
+  test_spans ();
+  test_spans_2 ();
+  test_spans_3 ();
+  test_double_width_chars ();
+  test_ipv4_header ();
+  test_missing_cells ();
+  test_add_row ();
+  test_alignment ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/table.h b/gcc/text-art/table.h
new file mode 100644
index 00000000000..5e6c8ffb836
--- /dev/null
+++ b/gcc/text-art/table.h
@@ -0,0 +1,262 @@
+/* Support for tabular/grid-based content.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_TABLE_H
+#define GCC_TEXT_ART_TABLE_H
+
+#include "text-art/canvas.h"
+#include "text-art/theme.h"
+#include <vector>
+
+namespace text_art {
+
+class table;
+class table_geometry;
+
+/* A class representing the content of a particular table cell,
+   or of a span of table cells.  */
+
+class table_cell_content
+{
+ public:
+  table_cell_content () : m_str (), m_size (0, 0) {}
+  table_cell_content (styled_string &&s);
+
+  bool operator== (const table_cell_content &other) const
+  {
+    return m_str == other.m_str;
+  }
+
+  canvas::size_t get_canvas_size () const { return m_size; }
+
+  void paint_to_canvas (canvas &canvas,
+			canvas::coord_t top_left) const;
+
+ private:
+  styled_string m_str;
+  canvas::size_t m_size;
+};
+
+/* A list of required sizes of table rows or columns
+   in canvas units (row heights or column widths).  */
+
+struct table_dimension_sizes
+{
+  table_dimension_sizes (unsigned num);
+
+  void require (unsigned idx, int amount)
+  {
+    m_requirements[idx] = std::max (m_requirements[idx], amount);
+  }
+
+  std::vector<int> m_requirements;
+};
+
+/* A 2D grid of cells.  Instances of table_cell_content can be assigned
+   to individual table cells, and to rectangular spans of cells.  Such
+   assignments do not have to fully cover the 2D grid, but they must not
+   overlap.  */
+
+class table
+{
+ public:
+  typedef size<class table> size_t;
+  typedef coord<class table> coord_t;
+  typedef range<class table> range_t;
+  typedef rect<class table> rect_t;
+
+  /* A record of how a table_cell_content was placed at a table::rect_t
+     with a certain alignment.  */
+  class cell_placement
+  {
+  public:
+    cell_placement (rect_t rect,
+		    table_cell_content &&content,
+		    x_align x_align,
+		    y_align y_align)
+    : m_rect (rect),
+      m_content (std::move (content)),
+      m_x_align (x_align),
+      m_y_align (y_align)
+    {
+    }
+
+    bool one_by_one_p () const
+    {
+      return m_rect.m_size.w == 1 && m_rect.m_size.h == 1;
+    }
+
+    canvas::size_t get_min_canvas_size () const
+    {
+      // Doesn't include border
+      return m_content.get_canvas_size ();
+    }
+
+    void paint_cell_contents_to_canvas(canvas &canvas,
+				       canvas::coord_t offset,
+				       const table_geometry &tg) const;
+
+    const table_cell_content &get_content () const { return m_content; }
+
+  private:
+    friend class table_cell_sizes;
+    rect_t m_rect;
+    table_cell_content m_content;
+    x_align m_x_align;
+    y_align m_y_align;
+  };
+
+  table (size_t size);
+  ~table () = default;
+  table (table &&) = default;
+  table (const table &) = delete;
+  table &operator= (const table &) = delete;
+
+  const size_t &get_size () const { return m_size; }
+
+  int add_row ()
+  {
+    m_size.h++;
+    m_occupancy.add_row (-1);
+    return m_size.h - 1; // return the table_y of the newly-added row
+  }
+
+  void set_cell (coord_t coord,
+		 table_cell_content &&content,
+		 enum x_align x_align = x_align::CENTER,
+		 enum y_align y_align = y_align::CENTER);
+
+  void set_cell_span (rect_t span,
+		      table_cell_content &&content,
+		      enum x_align x_align = x_align::CENTER,
+		      enum y_align y_align = y_align::CENTER);
+
+  canvas to_canvas (const theme &theme, const style_manager &sm) const;
+
+  void paint_to_canvas(canvas &canvas,
+		       canvas::coord_t offset,
+		       const table_geometry &tg,
+		       const theme &theme) const;
+
+  void debug () const;
+
+  /* Self-test support.  */
+  const cell_placement *get_placement_at (coord_t coord) const;
+
+ private:
+  int get_occupancy_safe (coord_t coord) const;
+  directions get_connections (int table_x, int table_y) const;
+  void paint_cell_borders_to_canvas(canvas &canvas,
+				    canvas::coord_t offset,
+				    const table_geometry &tg,
+				    const theme &theme) const;
+  void paint_cell_contents_to_canvas(canvas &canvas,
+				     canvas::coord_t offset,
+				     const table_geometry &tg) const;
+
+  friend class table_cell_sizes;
+
+  size_t m_size;
+  std::vector<cell_placement> m_placements;
+  array2<int, size_t, coord_t> m_occupancy; /* indices into the m_placements vec.  */
+};
+
+/* A workspace for computing the row heights and column widths
+   of a table (in canvas units).
+   The col_widths and row_heights could be shared between multiple
+   instances, for aligning multiple tables vertically or horizontally.  */
+
+class table_cell_sizes
+{
+ public:
+  table_cell_sizes (table_dimension_sizes &col_widths,
+		    table_dimension_sizes &row_heights)
+  : m_col_widths (col_widths),
+    m_row_heights (row_heights)
+  {
+  }
+
+  void pass_1 (const table &table);
+  void pass_2 (const table &table);
+
+  canvas::size_t get_canvas_size (const table::rect_t &rect) const;
+
+  table_dimension_sizes &m_col_widths;
+  table_dimension_sizes &m_row_heights;
+};
+
+/* A class responsible for mapping from table cell coords
+   to canvas coords, handling column widths.
+   It's the result of solving "how big are all the table cells and where
+   do they go?"
+   The cell_sizes are passed in, for handling aligning multiple tables,
+   sharing column widths or row heights.  */
+
+class table_geometry
+{
+ public:
+  table_geometry (const table &table, table_cell_sizes &cell_sizes);
+
+  void recalc_coords ();
+
+  const canvas::size_t get_canvas_size () const { return m_canvas_size; }
+
+  canvas::coord_t table_to_canvas (table::coord_t table_coord) const;
+  int table_x_to_canvas_x (int table_x) const;
+  int table_y_to_canvas_y (int table_y) const;
+
+  int get_col_width (int table_x) const
+  {
+    return m_cell_sizes.m_col_widths.m_requirements[table_x];
+  }
+
+  canvas::size_t get_canvas_size (const table::rect_t &rect) const
+  {
+    return m_cell_sizes.get_canvas_size (rect);
+  }
+
+ private:
+  const table &m_table;
+  table_cell_sizes &m_cell_sizes;
+  canvas::size_t m_canvas_size;
+
+  /* Start canvas column of table cell, including leading border.  */
+  std::vector<int> m_col_start_x;
+
+  /* Start canvas row of table cell, including leading border.  */
+  std::vector<int> m_row_start_y;
+};
+
+/* Helper class for handling the simple case of a single table
+   that doesn't need to be aligned with respect to anything else.  */
+
+struct simple_table_geometry
+{
+  simple_table_geometry (const table &table);
+
+  table_dimension_sizes m_col_widths;
+  table_dimension_sizes m_row_heights;
+  table_cell_sizes m_cell_sizes;
+  table_geometry m_tg;
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_TABLE_H */
diff --git a/gcc/text-art/theme.cc b/gcc/text-art/theme.cc
new file mode 100644
index 00000000000..54dfe7c9213
--- /dev/null
+++ b/gcc/text-art/theme.cc
@@ -0,0 +1,183 @@
+/* Classes for abstracting ascii vs unicode output.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "pretty-print.h"
+#include "selftest.h"
+#include "text-art/selftests.h"
+#include "text-art/ruler.h"
+#include "text-art/theme.h"
+
+using namespace text_art;
+
+/* class theme.  */
+
+void
+theme::paint_y_arrow (canvas &canvas,
+		      int canvas_x,
+		      canvas::range_t y_range,
+		      y_arrow_dir dir,
+		      style::id_t style_id) const
+{
+  int canvas_y;
+  int delta_y;
+  const canvas::cell_t head (get_cppchar (dir == y_arrow_dir::UP
+					  ? cell_kind::Y_ARROW_UP_HEAD
+					  : cell_kind::Y_ARROW_DOWN_HEAD),
+			     false, style_id);
+  const canvas::cell_t tail (get_cppchar (dir == y_arrow_dir::UP
+					  ? cell_kind::Y_ARROW_UP_TAIL
+					  : cell_kind::Y_ARROW_DOWN_TAIL),
+			     false, style_id);
+  if (dir == y_arrow_dir::UP)
+    {
+      canvas_y = y_range.get_max ();
+      delta_y = -1;
+    }
+  else
+    {
+      canvas_y = y_range.get_min ();
+      delta_y = 1;
+    }
+  for (int len = y_range.get_size (); len; len--)
+    {
+      const canvas::cell_t cell = (len > 1) ? tail : head;
+      canvas.paint (canvas::coord_t (canvas_x, canvas_y), cell);
+      canvas_y += delta_y;
+    }
+}
+
+/* class ascii_theme : public theme.  */
+
+canvas::cell_t
+ascii_theme::get_line_art (directions line_dirs) const
+{
+  if (line_dirs.m_up
+      && line_dirs.m_down
+      && !(line_dirs.m_left || line_dirs.m_right))
+    return canvas::cell_t ('|');
+  if (line_dirs.m_left
+      && line_dirs.m_right
+      && !(line_dirs.m_up || line_dirs.m_down))
+    return canvas::cell_t ('-');
+  if (line_dirs.m_up
+      || line_dirs.m_down
+      || line_dirs.m_left
+      || line_dirs.m_right)
+    return canvas::cell_t ('+');
+  return canvas::cell_t (' ');
+}
+
+cppchar_t
+ascii_theme::get_cppchar (enum cell_kind kind) const
+{
+  switch (kind)
+    {
+    default:
+      gcc_unreachable ();
+    case cell_kind::X_RULER_LEFT_EDGE:
+      return '|';
+    case cell_kind::X_RULER_MIDDLE:
+      return '~';
+    case cell_kind::X_RULER_INTERNAL_EDGE:
+      return '|';
+    case cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW:
+    case cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE:
+      return '+';
+    case cell_kind::X_RULER_RIGHT_EDGE:
+      return '|';
+    case cell_kind::X_RULER_VERTICAL_CONNECTOR:
+      return '|';
+
+    case cell_kind::TEXT_BORDER_HORIZONTAL:
+      return '-';
+    case cell_kind::TEXT_BORDER_VERTICAL:
+      return '|';
+    case cell_kind::TEXT_BORDER_TOP_LEFT:
+    case cell_kind::TEXT_BORDER_TOP_RIGHT:
+    case cell_kind::TEXT_BORDER_BOTTOM_LEFT:
+    case cell_kind::TEXT_BORDER_BOTTOM_RIGHT:
+      return '+';
+
+    case cell_kind::Y_ARROW_UP_HEAD: return '^';
+    case cell_kind::Y_ARROW_DOWN_HEAD: return 'v';
+
+    case cell_kind::Y_ARROW_UP_TAIL:
+    case cell_kind::Y_ARROW_DOWN_TAIL:
+      return '|';
+    }
+}
+
+/* class unicode_theme : public theme.  */
+
+canvas::cell_t
+unicode_theme::get_line_art (directions line_dirs) const
+{
+  return canvas::cell_t (get_box_drawing_char (line_dirs));
+}
+
+cppchar_t
+unicode_theme::get_cppchar (enum cell_kind kind) const
+{
+  switch (kind)
+    {
+    default:
+      gcc_unreachable ();
+    case cell_kind::X_RULER_LEFT_EDGE:
+      return 0x251C; /* "├": U+251C: BOX DRAWINGS LIGHT VERTICAL AND RIGHT */
+    case cell_kind::X_RULER_MIDDLE:
+      return 0x2500; /* "─": U+2500: BOX DRAWINGS LIGHT HORIZONTAL */
+    case cell_kind::X_RULER_INTERNAL_EDGE:
+      return 0x253C; /* "┼": U+253C: BOX DRAWINGS LIGHT VERTICAL AND HORIZONTAL */
+    case cell_kind::X_RULER_CONNECTOR_TO_LABEL_BELOW:
+      return 0x252C; /* "┬": U+252C: BOX DRAWINGS LIGHT DOWN AND HORIZONTAL */
+    case cell_kind::X_RULER_CONNECTOR_TO_LABEL_ABOVE:
+      return 0x2534; /* "┴": U+2534: BOX DRAWINGS LIGHT UP AND HORIZONTAL */
+    case cell_kind::X_RULER_RIGHT_EDGE:
+      return 0x2524; /* "┤": U+2524: BOX DRAWINGS LIGHT VERTICAL AND LEFT */
+    case cell_kind::X_RULER_VERTICAL_CONNECTOR:
+      return 0x2502; /* "│": U+2502: BOX DRAWINGS LIGHT VERTICAL */
+
+    case cell_kind::TEXT_BORDER_HORIZONTAL:
+      return 0x2500; /* "─": U+2500: BOX DRAWINGS LIGHT HORIZONTAL */
+    case cell_kind::TEXT_BORDER_VERTICAL:
+      return 0x2502; /* "│": U+2502: BOX DRAWINGS LIGHT VERTICAL */
+
+    /* Round corners.  */
+    case cell_kind::TEXT_BORDER_TOP_LEFT:
+      return 0x256D; /* "╭": U+256D BOX DRAWINGS LIGHT ARC DOWN AND RIGHT.  */
+    case cell_kind::TEXT_BORDER_TOP_RIGHT:
+      return 0x256E; /* "╮": U+256E BOX DRAWINGS LIGHT ARC DOWN AND LEFT.  */
+    case cell_kind::TEXT_BORDER_BOTTOM_LEFT:
+      return 0x2570; /* "╰": U+2570 BOX DRAWINGS LIGHT ARC UP AND RIGHT.  */
+    case cell_kind::TEXT_BORDER_BOTTOM_RIGHT:
+      return 0x256F; /* "╯": U+256F BOX DRAWINGS LIGHT ARC UP AND LEFT.  */
+
+    case cell_kind::Y_ARROW_UP_HEAD:
+      return '^';
+    case cell_kind::Y_ARROW_DOWN_HEAD:
+      return 'v';
+    case cell_kind::Y_ARROW_UP_TAIL:
+    case cell_kind::Y_ARROW_DOWN_TAIL:
+      return 0x2502; /* "│": U+2502: BOX DRAWINGS LIGHT VERTICAL */
+    }
+}
diff --git a/gcc/text-art/theme.h b/gcc/text-art/theme.h
new file mode 100644
index 00000000000..8edbc6efc76
--- /dev/null
+++ b/gcc/text-art/theme.h
@@ -0,0 +1,123 @@
+/* Classes for abstracting ascii vs unicode output.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_THEME_H
+#define GCC_TEXT_ART_THEME_H
+
+#include "text-art/canvas.h"
+#include "text-art/box-drawing.h"
+
+namespace text_art {
+
+class theme
+{
+ public:
+  enum class cell_kind
+  {
+    /* A left-hand edge of a range e.g. "├".  */
+    X_RULER_LEFT_EDGE,
+
+    /* Within a range e.g. "─".  */
+    X_RULER_MIDDLE,
+
+    /* A border between two neighboring ranges e.g. "┼".  */
+    X_RULER_INTERNAL_EDGE,
+
+    /* The connector with the text label within a range e.g. "┬".  */
+    X_RULER_CONNECTOR_TO_LABEL_BELOW,
+
+    /* As above, but when the text label is above the ruler.  */
+    X_RULER_CONNECTOR_TO_LABEL_ABOVE,
+
+    /* The vertical connection to a text label.  */
+    X_RULER_VERTICAL_CONNECTOR,
+
+    /* A right-hand edge of a range e.g. "┤".  */
+    X_RULER_RIGHT_EDGE,
+
+    TEXT_BORDER_HORIZONTAL,
+    TEXT_BORDER_VERTICAL,
+    TEXT_BORDER_TOP_LEFT,
+    TEXT_BORDER_TOP_RIGHT,
+    TEXT_BORDER_BOTTOM_LEFT,
+    TEXT_BORDER_BOTTOM_RIGHT,
+
+    Y_ARROW_UP_HEAD,
+    Y_ARROW_UP_TAIL,
+    Y_ARROW_DOWN_HEAD,
+    Y_ARROW_DOWN_TAIL,
+  };
+
+  virtual ~theme () = default;
+
+  virtual bool unicode_p () const = 0;
+  virtual bool emojis_p () const = 0;
+
+  virtual canvas::cell_t
+  get_line_art (directions line_dirs) const = 0;
+
+  canvas::cell_t get_cell (enum cell_kind kind, unsigned style_idx) const
+  {
+    return canvas::cell_t (get_cppchar (kind), false, style_idx);
+  }
+
+  virtual cppchar_t get_cppchar (enum cell_kind kind) const = 0;
+
+  enum class y_arrow_dir { UP, DOWN };
+  void paint_y_arrow (canvas &canvas,
+		      int x,
+		      canvas::range_t y_range,
+		      y_arrow_dir dir,
+		      style::id_t style_id) const;
+};
+
+class ascii_theme : public theme
+{
+ public:
+  bool unicode_p () const final override { return false; }
+  bool emojis_p () const final override { return false; }
+
+  canvas::cell_t
+  get_line_art (directions line_dirs) const final override;
+
+  cppchar_t get_cppchar (enum cell_kind kind) const final override;
+};
+
+class unicode_theme : public theme
+{
+ public:
+  bool unicode_p () const final override { return true; }
+  bool emojis_p () const override { return false; }
+
+  canvas::cell_t
+  get_line_art (directions line_dirs) const final override;
+
+  cppchar_t get_cppchar (enum cell_kind kind) const final override;
+};
+
+class emoji_theme : public unicode_theme
+{
+public:
+  bool emojis_p () const final override { return true; }
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_THEME_H */
diff --git a/gcc/text-art/types.h b/gcc/text-art/types.h
new file mode 100644
index 00000000000..b66188ae19c
--- /dev/null
+++ b/gcc/text-art/types.h
@@ -0,0 +1,504 @@
+/* Types for drawing 2d "text art".
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_TYPES_H
+#define GCC_TEXT_ART_TYPES_H
+
+#include "cpplib.h"
+#include "pretty-print.h"
+#include <vector>
+#include <string>
+
+namespace text_art {
+
+/* Forward decls.  */
+
+class canvas;
+class table;
+class theme;
+
+/* Classes for geometry.
+   We use templates to avoid mixing up e.g. canvas coordinates
+   with table coordinates.  */
+
+template <typename CoordinateSystem>
+struct size
+{
+  size (int w_, int h_) : w (w_), h (h_) {}
+  int w;
+  int h;
+};
+
+template <typename CoordinateSystem>
+struct coord
+{
+  coord (int x_, int y_) : x (x_), y (y_) {}
+  int x;
+  int y;
+};
+
+template <typename CoordinateSystem>
+coord<CoordinateSystem> operator+ (coord<CoordinateSystem> a,
+				   coord<CoordinateSystem> b)
+{
+  return coord<CoordinateSystem> (a.x + b.x, a.y + b.y);
+}
+
+/* A half-open range [start, next) of int.  */
+
+template <typename CoordinateSystem>
+struct range
+{
+  range (int start_, int next_)
+  : start (start_), next (next_)
+  {}
+
+  int get_min () const { return start; }
+  int get_max () const { return next - 1; }
+  int get_next () const { return next; }
+  int get_size () const { return next - start; }
+
+  int get_midpoint () const { return get_min () + get_size () / 2; }
+
+  int start;
+  int next;
+};
+
+/* A rectangle area within CoordinateSystem.  */
+
+template <typename CoordinateSystem>
+struct rect
+{
+  rect (coord<CoordinateSystem> top_left,
+	size<CoordinateSystem> size)
+  : m_top_left (top_left),
+    m_size (size)
+  {
+  }
+
+  rect (range<CoordinateSystem> x_range,
+	range<CoordinateSystem> y_range)
+  : m_top_left (x_range.get_min (), y_range.get_min ()),
+    m_size (x_range.get_size (), y_range.get_size ())
+  {
+  }
+
+  int get_min_x () const { return m_top_left.x; }
+  int get_min_y () const { return m_top_left.y; }
+  int get_max_x () const { return m_top_left.x + m_size.w - 1; }
+  int get_max_y () const { return m_top_left.y + m_size.h - 1; }
+  int get_next_x () const { return m_top_left.x + m_size.w; }
+  int get_next_y () const { return m_top_left.y + m_size.h; }
+
+  range<CoordinateSystem> get_x_range () const
+  {
+    return range<CoordinateSystem> (get_min_x (), get_next_x ());
+  }
+  range<CoordinateSystem> get_y_range () const
+  {
+    return range<CoordinateSystem> (get_min_y (), get_next_y ());
+  }
+
+  int get_width () const { return m_size.w; }
+  int get_height () const { return m_size.h; }
+
+  coord<CoordinateSystem> m_top_left;
+  size<CoordinateSystem> m_size;
+};
+
+template <typename ElementType, typename SizeType, typename CoordType>
+class array2
+{
+ public:
+  typedef ElementType element_t;
+  typedef SizeType size_t;
+  typedef CoordType coord_t;
+
+  array2 (size_t sz)
+  : m_size (sz),
+    m_elements (sz.w * sz.h)
+  {
+  }
+  array2 (array2 &&other)
+  : m_size (other.m_size),
+    m_elements (std::move (other.m_elements))
+  {
+  }
+
+  /* Move assignment not implemented or used.  */
+  array2 &operator== (array2 &&other) = delete;
+
+  /* No copy ctor or assignment op.  */
+  array2 (const array2 &other) = delete;
+  array2 &operator= (const array2 &other) = delete;
+
+
+  const size_t &get_size () const { return m_size; }
+
+  void add_row (const element_t &element)
+  {
+    m_size.h++;
+    m_elements.insert (m_elements.end (), m_size.w, element);
+  }
+
+  const element_t &get (const coord_t &coord) const
+  {
+    ::size_t idx = get_idx (coord);
+    return m_elements[idx];
+  }
+
+  void set (const coord_t &coord, const element_t &element)
+  {
+    ::size_t idx = get_idx (coord);
+    m_elements[idx] = element;
+  }
+
+  void fill (element_t element)
+  {
+    for (int y = 0; y < m_size.h; y++)
+      for (int x = 0; x < m_size.w; x++)
+	set (coord_t (x, y), element);
+  }
+
+ private:
+  ::size_t get_idx (const coord_t &coord) const
+  {
+    gcc_assert (coord.x >= 0);
+    gcc_assert (coord.x < m_size.w);
+    gcc_assert (coord.y >= 0);
+    gcc_assert (coord.y < m_size.h);
+    return (coord.y * m_size.w) + coord.x;
+  }
+
+  size_t m_size;
+  std::vector<element_t> m_elements;
+};
+
+/* A combination of attributes describing how to style a text cell.
+   We only support those attributes mentioned in invoke.texi:
+   - bold,
+   - underscore,
+   - blink,
+   - inverse,
+   - colors for foreground and background:
+     - default color
+     - named colors
+     - 16-color mode colors (the "bright" variants)
+     - 88-color mode
+     - 256-color mode
+   plus URLs. */
+
+struct style
+{
+  typedef unsigned char id_t;
+  static const id_t id_plain = 0;
+
+  /* Colors.  */
+  enum class named_color
+  {
+   DEFAULT,
+   // ANSI order
+   BLACK,
+   RED,
+   GREEN,
+   YELLOW,
+   BLUE,
+   MAGENTA,
+   CYAN,
+   WHITE
+  };
+
+
+  struct color
+  {
+    enum class kind
+    {
+      NAMED,
+      BITS_8,
+      BITS_24,
+    } m_kind;
+
+    union
+    {
+      struct {
+	enum named_color m_name;
+	bool m_bright;
+      } m_named;
+      uint8_t m_8bit;
+      struct {
+	uint8_t r;
+	uint8_t g;
+	uint8_t b;
+      } m_24bit;
+    } u;
+
+    /* Constructor for named colors.  */
+    color (enum named_color name = named_color::DEFAULT,
+	   bool bright = false)
+    : m_kind (kind::NAMED)
+    {
+      u.m_named.m_name = name;
+      u.m_named.m_bright = bright;
+    }
+
+    /* Constructor for 8-bit colors.  */
+    color (uint8_t col_val)
+    : m_kind (kind::BITS_8)
+    {
+      u.m_8bit = col_val;
+    }
+
+    /* Constructor for 24-bit colors.  */
+    color (uint8_t r, uint8_t g, uint8_t b)
+    : m_kind (kind::BITS_24)
+    {
+      u.m_24bit.r = r;
+      u.m_24bit.g = g;
+      u.m_24bit.b = b;
+    }
+
+    bool operator== (const color &other) const;
+    bool operator!= (const color &other) const
+    {
+      return !(*this == other);
+    }
+
+    void print_sgr (pretty_printer *pp, bool fg, bool &need_separator) const;
+  };
+
+  style ()
+  : m_bold (false),
+    m_underscore (false),
+    m_blink (false),
+    m_reverse (false),
+    m_fg_color (named_color::DEFAULT),
+    m_bg_color (named_color::DEFAULT),
+    m_url ()
+  {}
+
+  bool operator== (const style &other) const
+  {
+    return (m_bold == other.m_bold
+	    && m_underscore == other.m_underscore
+	    && m_blink == other.m_blink
+	    && m_reverse == other.m_reverse
+	    && m_fg_color == other.m_fg_color
+	    && m_bg_color == other.m_bg_color
+	    && m_url == other.m_url);
+  }
+
+  style &set_style_url (const char *url);
+
+  static void print_changes (pretty_printer *pp,
+			     const style &old_style,
+			     const style &new_style);
+
+  bool m_bold;
+  bool m_underscore;
+  bool m_blink;
+  bool m_reverse;
+  color m_fg_color;
+  color m_bg_color;
+  std::vector<cppchar_t> m_url; // empty = no URL
+};
+
+/* A class to keep track of all the styles in use in a drawing, so that
+   we can refer to them via the compact style::id_t type, rather than
+   via e.g. pointers.  */
+
+class style_manager
+{
+ public:
+  style_manager ();
+  style::id_t get_or_create_id (const style &style);
+  const style &get_style (style::id_t id) const
+  {
+    return m_styles[id];
+  }
+  void print_any_style_changes (pretty_printer *pp,
+				style::id_t old_id,
+				style::id_t new_id) const;
+  unsigned get_num_styles () const { return m_styles.size (); }
+
+private:
+  std::vector<style> m_styles;
+};
+
+class styled_unichar
+{
+ public:
+  friend class styled_string;
+
+  explicit styled_unichar ()
+  : m_code (0),
+    m_style_id (style::id_plain)
+  {}
+  explicit styled_unichar (cppchar_t ch)
+  : m_code (ch),
+    m_emoji_variant_p (false),
+    m_style_id (style::id_plain)
+  {}
+  explicit styled_unichar (cppchar_t ch, bool emoji, style::id_t style_id)
+  : m_code (ch),
+    m_emoji_variant_p (emoji),
+    m_style_id (style_id)
+  {
+    gcc_assert (style_id <= 0x7f);
+  }
+
+  cppchar_t get_code () const { return m_code; }
+  bool emoji_variant_p () const { return m_emoji_variant_p; }
+  style::id_t get_style_id () const { return m_style_id; }
+
+  bool double_width_p () const
+  {
+    int width = cpp_wcwidth (get_code ());
+    gcc_assert (width == 1 || width == 2);
+    return width == 2;
+  }
+
+  bool operator== (const styled_unichar &other) const
+  {
+    return (m_code == other.m_code
+	    && m_emoji_variant_p == other.m_emoji_variant_p
+	    && m_style_id == other.m_style_id);
+  }
+
+  void set_emoji_variant () { m_emoji_variant_p = true; }
+
+  int get_canvas_width () const
+  {
+      return cpp_wcwidth (m_code);
+  }
+
+  void add_combining_char (cppchar_t ch)
+  {
+    m_combining_chars.push_back (ch);
+  }
+
+  const std::vector<cppchar_t> get_combining_chars () const
+  {
+    return m_combining_chars;
+  }
+
+private:
+  cppchar_t m_code : 24;
+  bool m_emoji_variant_p : 1;
+  style::id_t m_style_id : 7;
+  std::vector<cppchar_t> m_combining_chars;
+};
+
+class styled_string
+{
+ public:
+  explicit styled_string () = default;
+  explicit styled_string (style_manager &sm, const char *str);
+  explicit styled_string (cppchar_t cppchar, bool emoji = false);
+
+  styled_string (styled_string &&) = default;
+  styled_string &operator= (styled_string &&) = default;
+
+  /* No copy ctor or assignment op.  */
+  styled_string (const styled_string &) = delete;
+  styled_string &operator= (const styled_string &) = delete;
+
+  /* For the few cases where copying is required, spell it out explicitly.  */
+  styled_string copy () const
+  {
+    styled_string result;
+    result.m_chars = m_chars;
+    return result;
+  }
+
+  bool operator== (const styled_string &other) const
+  {
+    return m_chars == other.m_chars;
+  }
+
+  static styled_string from_fmt (style_manager &sm,
+				 printer_fn format_decoder,
+				 const char *fmt, ...)
+    ATTRIBUTE_GCC_PPDIAG(3, 4);
+  static styled_string from_fmt_va (style_manager &sm,
+				    printer_fn format_decoder,
+				    const char *fmt,
+				    va_list *args)
+    ATTRIBUTE_GCC_PPDIAG(3, 0);
+
+  size_t size () const { return m_chars.size (); }
+  styled_unichar operator[] (size_t idx) const { return m_chars[idx]; }
+
+  std::vector<styled_unichar>::const_iterator begin () const
+  {
+    return m_chars.begin ();
+  }
+  std::vector<styled_unichar>::const_iterator end () const
+  {
+    return m_chars.end ();
+  }
+
+  int calc_canvas_width () const;
+
+  void append (const styled_string &suffix);
+
+  void set_url (style_manager &sm, const char *url);
+
+private:
+  std::vector<styled_unichar> m_chars;
+};
+
+enum class x_align
+{
+  LEFT,
+  CENTER,
+  RIGHT
+};
+
+enum class y_align
+{
+  TOP,
+  CENTER,
+  BOTTOM
+};
+
+/* A set of cardinal directions within a canvas or table.  */
+
+struct directions
+{
+public:
+  directions (bool up, bool down, bool left, bool right)
+  : m_up (up), m_down (down), m_left (left), m_right (right)
+  {
+  }
+
+  size_t as_index () const
+  {
+    return (m_up << 3) | (m_down << 2) | (m_left << 1) | m_right;
+  }
+
+  bool m_up: 1;
+  bool m_down: 1;
+  bool m_left: 1;
+  bool m_right: 1;
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_TYPES_H */
diff --git a/gcc/text-art/widget.cc b/gcc/text-art/widget.cc
new file mode 100644
index 00000000000..e6e544d5035
--- /dev/null
+++ b/gcc/text-art/widget.cc
@@ -0,0 +1,275 @@
+/* Hierarchical diagram elements.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free
+Software Foundation; either version 3, or (at your option) any later
+version.
+
+GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or
+FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#include "config.h"
+#define INCLUDE_MEMORY
+#include "system.h"
+#include "coretypes.h"
+#include "pretty-print.h"
+#include "selftest.h"
+#include "make-unique.h"
+#include "text-art/selftests.h"
+#include "text-art/widget.h"
+
+using namespace text_art;
+
+/* class text_art::widget.  */
+
+canvas
+widget::to_canvas (const style_manager &style_mgr)
+{
+  const canvas::size_t req_size = get_req_size ();
+
+  /* For now we don't constrain the allocation; we give
+     the widget the full size it requested, and widgets
+     assume they got their full size request.  */
+  const canvas::size_t alloc_size = req_size;
+
+  set_alloc_rect (canvas::rect_t (canvas::coord_t (0, 0), alloc_size));
+  canvas c (alloc_size, style_mgr);
+  paint_to_canvas (c);
+  return c;
+}
+
+/* class text_art::vbox_widget : public text_art::container_widget.  */
+
+const char *
+vbox_widget::get_desc () const
+{
+  return "vbox_widget";
+}
+
+canvas::size_t
+vbox_widget::calc_req_size ()
+{
+  canvas::size_t result (0, 0);
+  for (auto &child : m_children)
+    {
+      canvas::size_t child_req_size = child->get_req_size();
+      result.h += child_req_size.h;
+      result.w = std::max (result.w, child_req_size.w);
+    }
+  return result;
+}
+
+void
+vbox_widget::update_child_alloc_rects ()
+{
+  const int x = get_min_x ();
+  int y = get_min_y ();
+  for (auto &child : m_children)
+    {
+      child->set_alloc_rect
+	(canvas::rect_t (canvas::coord_t (x, y),
+			 canvas::size_t (get_alloc_w (),
+					 child->get_req_h ())));
+      y += child->get_req_h ();
+    }
+}
+
+/* class text_art::text_widget : public text_art::leaf_widget.  */
+
+const char *
+text_widget::get_desc () const
+{
+  return "text_widget";
+}
+
+canvas::size_t
+text_widget::calc_req_size ()
+{
+  return canvas::size_t (m_str.size (), 1);
+}
+
+void
+text_widget::paint_to_canvas (canvas &canvas)
+{
+  canvas.paint_text (get_top_left (), m_str);
+}
+
+/* class text_art::canvas_widget : public text_art::leaf_widget.  */
+
+const char *
+canvas_widget::get_desc () const
+{
+  return "canvas_widget";
+}
+
+canvas::size_t
+canvas_widget::calc_req_size ()
+{
+  return m_canvas.get_size ();
+}
+
+void
+canvas_widget::paint_to_canvas (canvas &canvas)
+{
+  for (int y = 0; y < m_canvas.get_size ().h; y++)
+    for (int x = 0; x < m_canvas.get_size ().w; x++)
+      {
+	canvas::coord_t rel_xy (x, y);
+	canvas.paint (get_top_left () + rel_xy,
+		      m_canvas.get (rel_xy));
+      }
+}
+
+#if CHECKING_P
+
+namespace selftest {
+
+/* Concrete widget subclass for writing selftests.
+   Requests a hard-coded size, and fills its allocated rectangle
+   with a specific character.  */
+
+class test_widget : public leaf_widget
+{
+public:
+  test_widget (canvas::size_t size, char ch)
+  : m_test_size (size), m_ch (ch)
+  {}
+
+  const char *get_desc () const final override
+  {
+    return "test_widget";
+  }
+  canvas::size_t calc_req_size () final override
+  {
+    return m_test_size;
+  }
+  void paint_to_canvas (canvas &canvas) final override
+  {
+    canvas.fill (get_alloc_rect (), canvas::cell_t (m_ch));
+  }
+
+private:
+  canvas::size_t m_test_size;
+  char m_ch;
+};
+
+static void
+test_test_widget ()
+{
+  style_manager sm;
+  test_widget w (canvas::size_t (3, 3), 'A');
+  canvas c (w.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("AAA\n"
+      "AAA\n"
+      "AAA\n"));
+}
+
+static void
+test_text_widget ()
+{
+  style_manager sm;
+  text_widget w (styled_string (sm, "hello world"));
+  canvas c (w.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("hello world\n"));
+}
+
+static void
+test_wrapper_widget ()
+{
+  style_manager sm;
+  wrapper_widget w (::make_unique<test_widget> (canvas::size_t (3, 3), 'B'));
+  canvas c (w.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("BBB\n"
+      "BBB\n"
+      "BBB\n"));
+}
+
+static void
+test_vbox_1 ()
+{
+  style_manager sm;
+  vbox_widget w;
+  for (int i = 0; i < 5; i++)
+    w.add_child
+      (::make_unique <text_widget>
+       (styled_string::from_fmt (sm, nullptr,
+				 "this is line %i", i)));
+  canvas c (w.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("this is line 0\n"
+      "this is line 1\n"
+      "this is line 2\n"
+      "this is line 3\n"
+      "this is line 4\n"));
+}
+
+static void
+test_vbox_2 ()
+{
+  style_manager sm;
+  vbox_widget w;
+  w.add_child (::make_unique<test_widget> (canvas::size_t (1, 3), 'A'));
+  w.add_child (::make_unique<test_widget> (canvas::size_t (4, 1), 'B'));
+  w.add_child (::make_unique<test_widget> (canvas::size_t (1, 2), 'C'));
+  canvas c (w.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("AAAA\n"
+      "AAAA\n"
+      "AAAA\n"
+      "BBBB\n"
+      "CCCC\n"
+      "CCCC\n"));
+}
+
+static void
+test_canvas_widget ()
+{
+  style_manager sm;
+  canvas inner_canvas (canvas::size_t (5, 3), sm);
+  inner_canvas.fill (canvas::rect_t (canvas::coord_t (0, 0),
+				     canvas::size_t (5, 3)),
+		     canvas::cell_t ('a'));
+  canvas_widget cw (std::move (inner_canvas));
+  canvas c (cw.to_canvas (sm));
+  ASSERT_CANVAS_STREQ
+    (c, false,
+     ("aaaaa\n"
+      "aaaaa\n"
+      "aaaaa\n"));
+}
+
+/* Run all selftests in this file.  */
+
+void
+text_art_widget_cc_tests ()
+{
+  test_test_widget ();
+  test_text_widget ();
+  test_wrapper_widget ();
+  test_vbox_1 ();
+  test_vbox_2 ();
+  test_canvas_widget ();
+}
+
+} // namespace selftest
+
+
+#endif /* #if CHECKING_P */
diff --git a/gcc/text-art/widget.h b/gcc/text-art/widget.h
new file mode 100644
index 00000000000..91209444bf7
--- /dev/null
+++ b/gcc/text-art/widget.h
@@ -0,0 +1,246 @@
+/* Hierarchical diagram elements.
+   Copyright (C) 2023 Free Software Foundation, Inc.
+   Contributed by David Malcolm <dmalcolm@redhat.com>.
+
+This file is part of GCC.
+
+GCC is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 3, or (at your option)
+any later version.
+
+GCC is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GCC; see the file COPYING3.  If not see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef GCC_TEXT_ART_WIDGET_H
+#define GCC_TEXT_ART_WIDGET_H
+
+#include <vector>
+#include "text-art/canvas.h"
+#include "text-art/table.h"
+
+namespace text_art {
+
+/* Abstract base class: something that knows how to size itself and
+   how to paint itself to a canvas, potentially with children, with
+   support for hierarchical sizing and positioning.
+
+   Widgets have a two-phase sizing/positioning algorithm.
+
+   Step 1: size requests: the root widget is asked for its size request i.e
+   how big it wants to be.  This is handled by recursively asking child
+   widgets for their requested sizes.  Each widget subclass can implement
+   their own logic for this in the "calc_req_size" vfunc, and the result
+   is cached in m_req_size.
+
+   Step 2: rect allocation: the root widget is set a canvas::rect_t as
+   its "allocated" rectangle.  Each widget subclass can then place its
+   children recursively using the "update_child_alloc_rects" vfunc.
+   For simplicity, all coordinates in the hierarchy are within the same
+   coordinate system (rather than attempting to store per-child offsets).
+
+   Widget subclasses are responsible for managing their own children.  */
+
+/* Subclasses in this header, with indentation indicating inheritance.  */
+
+class widget;  /* Abstract base class.  */
+  class wrapper_widget;  /* Concrete subclass: a widget with a single child.  */
+  class container_widget; /* Abstract subclass: widgets with an arbitrary
+			     number of children.  */
+    class vbox_widget; /* Concrete widget subclass: lay out children
+			  vertically.  */
+  class leaf_widget; /* Abstract subclass: a widget with no children.  */
+    class text_widget; /* Concrete subclass: a text string.  */
+    class canvas_widget; /* Concrete subclass: a pre-rendered canvas.  */
+
+class widget
+{
+ public:
+  /* This can be very useful for debugging when implementing new
+     widget subclasses.  */
+  static const bool DEBUG_GEOMETRY = false;
+
+  virtual ~widget () {}
+
+  canvas to_canvas (const style_manager &style_mgr);
+
+  canvas::size_t get_req_size ()
+  {
+    m_req_size = calc_req_size();
+    if (DEBUG_GEOMETRY)
+      fprintf (stderr, "calc_req_size (%s) -> (w:%i, h:%i)\n",
+	       get_desc (),
+	       m_req_size.w, m_req_size.h);
+    return m_req_size;
+  }
+
+  void set_alloc_rect (const canvas::rect_t &rect)
+  {
+    if (DEBUG_GEOMETRY)
+      fprintf (stderr, "set_alloc_rect (%s): ((x:%i, y:%i), (w:%i, h:%i))\n",
+	       get_desc (),
+	       rect.m_top_left.x, rect.m_top_left.y,
+	       rect.m_size.w, rect.m_size.h);
+    m_alloc_rect = rect;
+    update_child_alloc_rects ();
+  }
+
+  virtual const char *get_desc () const = 0;
+  virtual canvas::size_t calc_req_size () = 0;
+  virtual void update_child_alloc_rects () = 0;
+  virtual void paint_to_canvas (canvas &canvas) = 0;
+
+  /* Access to the cached size request of this widget.  */
+  const canvas::size_t get_req_size () const { return m_req_size; }
+  int get_req_w () const { return m_req_size.w; }
+  int get_req_h () const { return m_req_size.h; }
+
+  /* Access to the allocated canvas coordinates of this widget.  */
+  const canvas::rect_t &get_alloc_rect () const { return m_alloc_rect; }
+  int get_alloc_w () const { return m_alloc_rect.get_width (); }
+  int get_alloc_h () const { return m_alloc_rect.get_height (); }
+  int get_min_x () const { return m_alloc_rect.get_min_x (); }
+  int get_max_x () const { return m_alloc_rect.get_max_x (); }
+  int get_next_x () const { return m_alloc_rect.get_next_x (); }
+  int get_min_y () const { return m_alloc_rect.get_min_y (); }
+  int get_max_y () const { return m_alloc_rect.get_max_y (); }
+  int get_next_y () const { return m_alloc_rect.get_max_y (); }
+  canvas::range_t get_x_range () const { return m_alloc_rect.get_x_range (); }
+  canvas::range_t get_y_range () const { return m_alloc_rect.get_y_range (); }
+  const canvas::coord_t &get_top_left () const
+  {
+    return m_alloc_rect.m_top_left;
+  }
+
+ protected:
+  widget ()
+  : m_req_size (0, 0),
+    m_alloc_rect (canvas::coord_t (0, 0),
+		  canvas::size_t (0, 0))
+  {}
+
+private:
+  /* How much size this widget requested.  */
+  canvas::size_t m_req_size;
+  /* Where (and how big) this widget was allocated.  */
+  canvas::rect_t m_alloc_rect;
+};
+
+/* Concrete subclass for a widget with a single child.  */
+
+class wrapper_widget : public widget
+{
+ public:
+  wrapper_widget (std::unique_ptr<widget> child)
+  : m_child (std::move (child))
+  {}
+
+  const char *get_desc () const override
+  {
+    return "wrapper_widget";
+  }
+  canvas::size_t calc_req_size () override
+  {
+    return m_child->get_req_size ();
+  }
+  void update_child_alloc_rects ()
+  {
+    m_child->set_alloc_rect (get_alloc_rect ());
+  }
+  void paint_to_canvas (canvas &canvas) override
+  {
+    m_child->paint_to_canvas (canvas);
+  }
+ private:
+  std::unique_ptr<widget> m_child;
+};
+
+/* Abstract subclass for widgets with an arbitrary number of children.  */
+
+class container_widget : public widget
+{
+ public:
+  void add_child (std::unique_ptr<widget> child)
+  {
+    m_children.push_back (std::move (child));
+  }
+
+  void paint_to_canvas (canvas &canvas) final override
+  {
+    for (auto &child : m_children)
+      child->paint_to_canvas (canvas);
+  }
+
+ protected:
+  std::vector<std::unique_ptr<widget>> m_children;
+};
+
+/* Concrete widget subclass: lay out children vertically.  */
+
+class vbox_widget : public container_widget
+{
+ public:
+  const char *get_desc () const override;
+  canvas::size_t calc_req_size () override;
+  void update_child_alloc_rects () final override;
+};
+
+/* Abstract subclass for widgets with no children.  */
+
+class leaf_widget : public widget
+{
+ public:
+  void update_child_alloc_rects () final override
+  {
+    /* no-op.  */
+  }
+
+ protected:
+  leaf_widget () : widget () {}
+};
+
+/* Concrete widget subclass for a text string.  */
+
+class text_widget : public leaf_widget
+{
+ public:
+  text_widget (styled_string str)
+  : leaf_widget (), m_str (std::move (str))
+  {
+  }
+
+  const char *get_desc () const override;
+  canvas::size_t calc_req_size () final override;
+  void paint_to_canvas (canvas &canvas) final override;
+
+private:
+  styled_string m_str;
+};
+
+/* Concrete widget subclass for a pre-rendered canvas.  */
+
+class canvas_widget : public leaf_widget
+{
+ public:
+  canvas_widget (canvas &&c)
+  : leaf_widget (), m_canvas (std::move (c))
+  {
+  }
+
+  const char *get_desc () const override;
+  canvas::size_t calc_req_size () final override;
+  void paint_to_canvas (canvas &canvas) final override;
+
+private:
+  canvas m_canvas;
+};
+
+} // namespace text_art
+
+#endif /* GCC_TEXT_ART_WIDGET_H */
diff --git a/libcpp/charset.cc b/libcpp/charset.cc
index d7f323b2cd5..a0bd2ede11c 100644
--- a/libcpp/charset.cc
+++ b/libcpp/charset.cc
@@ -3147,34 +3147,26 @@ cpp_display_column_to_byte_column (const char *data, int data_length,
   return dw.bytes_processed () + MAX (0, display_col - avail_display);
 }
 
-/* Our own version of wcwidth().  We don't use the actual wcwidth() in glibc,
-   because that will inspect the user's locale, and in particular in an ASCII
-   locale, it will not return anything useful for extended characters.  But GCC
-   in other respects (see e.g. _cpp_default_encoding()) behaves as if
-   everything is UTF-8.  We also make some tweaks that are useful for the way
-   GCC needs to use this data, e.g. tabs and other control characters should be
-   treated as having width 1.  The lookup tables are generated from
-   contrib/unicode/gen_wcwidth.py and were made by simply calling glibc
-   wcwidth() on all codepoints, then applying the small tweaks.  These tables
-   are not highly optimized, but for the present purpose of outputting
-   diagnostics, they are sufficient.  */
-
-#include "generated_cpp_wcwidth.h"
-int cpp_wcwidth (cppchar_t c)
+template <typename PropertyType>
+PropertyType
+get_cppchar_property (cppchar_t c,
+		      const cppchar_t *range_ends,
+		      const PropertyType *range_values,
+		      size_t num_ranges,
+		      PropertyType default_value)
 {
-  if (__builtin_expect (c <= wcwidth_range_ends[0], true))
-    return wcwidth_widths[0];
+  if (__builtin_expect (c <= range_ends[0], true))
+    return range_values[0];
 
   /* Binary search the tables.  */
   int begin = 1;
-  static const int end
-      = sizeof wcwidth_range_ends / sizeof (*wcwidth_range_ends);
+  static const int end = num_ranges;
   int len = end - begin;
   do
     {
       int half = len/2;
       int middle = begin + half;
-      if (c > wcwidth_range_ends[middle])
+      if (c > range_ends[middle])
 	{
 	  begin = middle + 1;
 	  len -= half + 1;
@@ -3184,6 +3176,61 @@ int cpp_wcwidth (cppchar_t c)
     } while (len);
 
   if (__builtin_expect (begin != end, true))
-    return wcwidth_widths[begin];
-  return 1;
+    return range_values[begin];
+
+  return default_value;
+}
+
+/* Our own version of wcwidth().  We don't use the actual wcwidth() in glibc,
+   because that will inspect the user's locale, and in particular in an ASCII
+   locale, it will not return anything useful for extended characters.  But GCC
+   in other respects (see e.g. _cpp_default_encoding()) behaves as if
+   everything is UTF-8.  We also make some tweaks that are useful for the way
+   GCC needs to use this data, e.g. tabs and other control characters should be
+   treated as having width 1.  The lookup tables are generated from
+   contrib/unicode/gen_wcwidth.py and were made by simply calling glibc
+   wcwidth() on all codepoints, then applying the small tweaks.  These tables
+   are not highly optimized, but for the present purpose of outputting
+   diagnostics, they are sufficient.  */
+
+#include "generated_cpp_wcwidth.h"
+
+int
+cpp_wcwidth (cppchar_t c)
+{
+  const size_t num_ranges
+    = sizeof wcwidth_range_ends / sizeof (*wcwidth_range_ends);
+  return get_cppchar_property<unsigned char > (c,
+					       &wcwidth_range_ends[0],
+					       &wcwidth_widths[0],
+					       num_ranges,
+					       1);
+}
+
+#include "combining-chars.inc"
+
+bool
+cpp_is_combining_char (cppchar_t c)
+{
+  const size_t num_ranges
+    = sizeof combining_range_ends / sizeof (*combining_range_ends);
+  return get_cppchar_property<bool> (c,
+				     &combining_range_ends[0],
+				     &is_combining[0],
+				     num_ranges,
+				     false);
+}
+
+#include "printable-chars.inc"
+
+bool
+cpp_is_printable_char (cppchar_t c)
+{
+  const size_t num_ranges
+    = sizeof printable_range_ends / sizeof (*printable_range_ends);
+  return get_cppchar_property<bool> (c,
+				     &printable_range_ends[0],
+				     &is_printable[0],
+				     num_ranges,
+				     false);
 }
diff --git a/libcpp/combining-chars.inc b/libcpp/combining-chars.inc
new file mode 100644
index 00000000000..dfec966970a
--- /dev/null
+++ b/libcpp/combining-chars.inc
@@ -0,0 +1,68 @@
+/* Generated by contrib/unicode/gen-combining-chars.py
+   using version 12.1.0 of the Unicode standard.  */
+
+static const cppchar_t combining_range_ends[] = {
+  0x2ff, 0x34e, 0x34f, 0x36f, 0x482, 0x487, 0x590, 0x5bd,
+  0x5be, 0x5bf, 0x5c0, 0x5c2, 0x5c3, 0x5c5, 0x5c6, 0x5c7,
+  0x60f, 0x61a, 0x64a, 0x65f, 0x66f, 0x670, 0x6d5, 0x6dc,
+  0x6de, 0x6e4, 0x6e6, 0x6e8, 0x6e9, 0x6ed, 0x710, 0x711,
+  0x72f, 0x74a, 0x7ea, 0x7f3, 0x7fc, 0x7fd, 0x815, 0x819,
+  0x81a, 0x823, 0x824, 0x827, 0x828, 0x82d, 0x858, 0x85b,
+  0x8d2, 0x8e1, 0x8e2, 0x8ff, 0x93b, 0x93c, 0x94c, 0x94d,
+  0x950, 0x954, 0x9bb, 0x9bc, 0x9cc, 0x9cd, 0x9fd, 0x9fe,
+  0xa3b, 0xa3c, 0xa4c, 0xa4d, 0xabb, 0xabc, 0xacc, 0xacd,
+  0xb3b, 0xb3c, 0xb4c, 0xb4d, 0xbcc, 0xbcd, 0xc4c, 0xc4d,
+  0xc54, 0xc56, 0xcbb, 0xcbc, 0xccc, 0xccd, 0xd3a, 0xd3c,
+  0xd4c, 0xd4d, 0xdc9, 0xdca, 0xe37, 0xe3a, 0xe47, 0xe4b,
+  0xeb7, 0xeba, 0xec7, 0xecb, 0xf17, 0xf19, 0xf34, 0xf35,
+  0xf36, 0xf37, 0xf38, 0xf39, 0xf70, 0xf72, 0xf73, 0xf74,
+  0xf79, 0xf7d, 0xf7f, 0xf80, 0xf81, 0xf84, 0xf85, 0xf87,
+  0xfc5, 0xfc6, 0x1036, 0x1037, 0x1038, 0x103a, 0x108c, 0x108d,
+  0x135c, 0x135f, 0x1713, 0x1714, 0x1733, 0x1734, 0x17d1, 0x17d2,
+  0x17dc, 0x17dd, 0x18a8, 0x18a9, 0x1938, 0x193b, 0x1a16, 0x1a18,
+  0x1a5f, 0x1a60, 0x1a74, 0x1a7c, 0x1a7e, 0x1a7f, 0x1aaf, 0x1abd,
+  0x1b33, 0x1b34, 0x1b43, 0x1b44, 0x1b6a, 0x1b73, 0x1ba9, 0x1bab,
+  0x1be5, 0x1be6, 0x1bf1, 0x1bf3, 0x1c36, 0x1c37, 0x1ccf, 0x1cd2,
+  0x1cd3, 0x1ce0, 0x1ce1, 0x1ce8, 0x1cec, 0x1ced, 0x1cf3, 0x1cf4,
+  0x1cf7, 0x1cf9, 0x1dbf, 0x1df9, 0x1dfa, 0x1dff, 0x20cf, 0x20dc,
+  0x20e0, 0x20e1, 0x20e4, 0x20f0, 0x2cee, 0x2cf1, 0x2d7e, 0x2d7f,
+  0x2ddf, 0x2dff, 0x3029, 0x302f, 0x3098, 0x309a, 0xa66e, 0xa66f,
+  0xa673, 0xa67d, 0xa69d, 0xa69f, 0xa6ef, 0xa6f1, 0xa805, 0xa806,
+  0xa8c3, 0xa8c4, 0xa8df, 0xa8f1, 0xa92a, 0xa92d, 0xa952, 0xa953,
+  0xa9b2, 0xa9b3, 0xa9bf, 0xa9c0, 0xaaaf, 0xaab0, 0xaab1, 0xaab4,
+  0xaab6, 0xaab8, 0xaabd, 0xaabf, 0xaac0, 0xaac1, 0xaaf5, 0xaaf6,
+  0xabec, 0xabed, 0xfb1d, 0xfb1e, 0xfe1f, 0xfe2f, 0x101fc, 0x101fd,
+  0x102df, 0x102e0, 0x10375, 0x1037a, 0x10a0c, 0x10a0d, 0x10a0e, 0x10a0f,
+  0x10a37, 0x10a3a, 0x10a3e, 0x10a3f, 0x10ae4, 0x10ae6, 0x10d23, 0x10d27,
+  0x10f45, 0x10f50, 0x11045, 0x11046, 0x1107e, 0x1107f, 0x110b8, 0x110ba,
+  0x110ff, 0x11102, 0x11132, 0x11134, 0x11172, 0x11173, 0x111bf, 0x111c0,
+  0x111c9, 0x111ca, 0x11234, 0x11236, 0x112e8, 0x112ea, 0x1133a, 0x1133c,
+  0x1134c, 0x1134d, 0x11365, 0x1136c, 0x1136f, 0x11374, 0x11441, 0x11442,
+  0x11445, 0x11446, 0x1145d, 0x1145e, 0x114c1, 0x114c3, 0x115be, 0x115c0,
+  0x1163e, 0x1163f, 0x116b5, 0x116b7, 0x1172a, 0x1172b, 0x11838, 0x1183a,
+  0x119df, 0x119e0, 0x11a33, 0x11a34, 0x11a46, 0x11a47, 0x11a98, 0x11a99,
+  0x11c3e, 0x11c3f, 0x11d41, 0x11d42, 0x11d43, 0x11d45, 0x11d96, 0x11d97,
+  0x16aef, 0x16af4, 0x16b2f, 0x16b36, 0x1bc9d, 0x1bc9e, 0x1d164, 0x1d169,
+  0x1d16c, 0x1d172, 0x1d17a, 0x1d182, 0x1d184, 0x1d18b, 0x1d1a9, 0x1d1ad,
+  0x1d241, 0x1d244, 0x1dfff, 0x1e006, 0x1e007, 0x1e018, 0x1e01a, 0x1e021,
+  0x1e022, 0x1e024, 0x1e025, 0x1e02a, 0x1e12f, 0x1e136, 0x1e2eb, 0x1e2ef,
+  0x1e8cf, 0x1e8d6, 0x1e943, 0x1e94a, 0x10fffe,
+};
+
+static const bool is_combining[] = {
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0,
+};
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index a6f0abd894c..d326f5aa316 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -1602,4 +1602,7 @@ bool cpp_input_conversion_is_trivial (const char *input_charset);
 int cpp_check_utf8_bom (const char *data, size_t data_length);
 bool cpp_valid_utf8_p (const char *data, size_t num_bytes);
 
+bool cpp_is_combining_char (cppchar_t c);
+bool cpp_is_printable_char (cppchar_t c);
+
 #endif /* ! LIBCPP_CPPLIB_H */
diff --git a/libcpp/printable-chars.inc b/libcpp/printable-chars.inc
new file mode 100644
index 00000000000..470b1eef331
--- /dev/null
+++ b/libcpp/printable-chars.inc
@@ -0,0 +1,231 @@
+/* Generated by contrib/unicode/gen-printable-chars.py
+   using version 12.1.0 of the Unicode standard.  */
+
+static const cppchar_t printable_range_ends[] = {
+  0x1f, 0x7e, 0x9f, 0xac, 0xad, 0x377, 0x379, 0x37f,
+  0x383, 0x38a, 0x38b, 0x38c, 0x38d, 0x3a1, 0x3a2, 0x52f,
+  0x530, 0x556, 0x558, 0x58a, 0x58c, 0x58f, 0x590, 0x5c7,
+  0x5cf, 0x5ea, 0x5ee, 0x5f4, 0x605, 0x61b, 0x61d, 0x6dc,
+  0x6dd, 0x70d, 0x70f, 0x74a, 0x74c, 0x7b1, 0x7bf, 0x7fa,
+  0x7fc, 0x82d, 0x82f, 0x83e, 0x83f, 0x85b, 0x85d, 0x85e,
+  0x85f, 0x86a, 0x89f, 0x8b4, 0x8b5, 0x8bd, 0x8d2, 0x8e1,
+  0x8e2, 0x983, 0x984, 0x98c, 0x98e, 0x990, 0x992, 0x9a8,
+  0x9a9, 0x9b0, 0x9b1, 0x9b2, 0x9b5, 0x9b9, 0x9bb, 0x9c4,
+  0x9c6, 0x9c8, 0x9ca, 0x9ce, 0x9d6, 0x9d7, 0x9db, 0x9dd,
+  0x9de, 0x9e3, 0x9e5, 0x9fe, 0xa00, 0xa03, 0xa04, 0xa0a,
+  0xa0e, 0xa10, 0xa12, 0xa28, 0xa29, 0xa30, 0xa31, 0xa33,
+  0xa34, 0xa36, 0xa37, 0xa39, 0xa3b, 0xa3c, 0xa3d, 0xa42,
+  0xa46, 0xa48, 0xa4a, 0xa4d, 0xa50, 0xa51, 0xa58, 0xa5c,
+  0xa5d, 0xa5e, 0xa65, 0xa76, 0xa80, 0xa83, 0xa84, 0xa8d,
+  0xa8e, 0xa91, 0xa92, 0xaa8, 0xaa9, 0xab0, 0xab1, 0xab3,
+  0xab4, 0xab9, 0xabb, 0xac5, 0xac6, 0xac9, 0xaca, 0xacd,
+  0xacf, 0xad0, 0xadf, 0xae3, 0xae5, 0xaf1, 0xaf8, 0xaff,
+  0xb00, 0xb03, 0xb04, 0xb0c, 0xb0e, 0xb10, 0xb12, 0xb28,
+  0xb29, 0xb30, 0xb31, 0xb33, 0xb34, 0xb39, 0xb3b, 0xb44,
+  0xb46, 0xb48, 0xb4a, 0xb4d, 0xb55, 0xb57, 0xb5b, 0xb5d,
+  0xb5e, 0xb63, 0xb65, 0xb77, 0xb81, 0xb83, 0xb84, 0xb8a,
+  0xb8d, 0xb90, 0xb91, 0xb95, 0xb98, 0xb9a, 0xb9b, 0xb9c,
+  0xb9d, 0xb9f, 0xba2, 0xba4, 0xba7, 0xbaa, 0xbad, 0xbb9,
+  0xbbd, 0xbc2, 0xbc5, 0xbc8, 0xbc9, 0xbcd, 0xbcf, 0xbd0,
+  0xbd6, 0xbd7, 0xbe5, 0xbfa, 0xbff, 0xc0c, 0xc0d, 0xc10,
+  0xc11, 0xc28, 0xc29, 0xc39, 0xc3c, 0xc44, 0xc45, 0xc48,
+  0xc49, 0xc4d, 0xc54, 0xc56, 0xc57, 0xc5a, 0xc5f, 0xc63,
+  0xc65, 0xc6f, 0xc76, 0xc8c, 0xc8d, 0xc90, 0xc91, 0xca8,
+  0xca9, 0xcb3, 0xcb4, 0xcb9, 0xcbb, 0xcc4, 0xcc5, 0xcc8,
+  0xcc9, 0xccd, 0xcd4, 0xcd6, 0xcdd, 0xcde, 0xcdf, 0xce3,
+  0xce5, 0xcef, 0xcf0, 0xcf2, 0xcff, 0xd03, 0xd04, 0xd0c,
+  0xd0d, 0xd10, 0xd11, 0xd44, 0xd45, 0xd48, 0xd49, 0xd4f,
+  0xd53, 0xd63, 0xd65, 0xd7f, 0xd81, 0xd83, 0xd84, 0xd96,
+  0xd99, 0xdb1, 0xdb2, 0xdbb, 0xdbc, 0xdbd, 0xdbf, 0xdc6,
+  0xdc9, 0xdca, 0xdce, 0xdd4, 0xdd5, 0xdd6, 0xdd7, 0xddf,
+  0xde5, 0xdef, 0xdf1, 0xdf4, 0xe00, 0xe3a, 0xe3e, 0xe5b,
+  0xe80, 0xe82, 0xe83, 0xe84, 0xe85, 0xe8a, 0xe8b, 0xea3,
+  0xea4, 0xea5, 0xea6, 0xebd, 0xebf, 0xec4, 0xec5, 0xec6,
+  0xec7, 0xecd, 0xecf, 0xed9, 0xedb, 0xedf, 0xeff, 0xf47,
+  0xf48, 0xf6c, 0xf70, 0xf97, 0xf98, 0xfbc, 0xfbd, 0xfcc,
+  0xfcd, 0xfda, 0xfff, 0x10c5, 0x10c6, 0x10c7, 0x10cc, 0x10cd,
+  0x10cf, 0x1248, 0x1249, 0x124d, 0x124f, 0x1256, 0x1257, 0x1258,
+  0x1259, 0x125d, 0x125f, 0x1288, 0x1289, 0x128d, 0x128f, 0x12b0,
+  0x12b1, 0x12b5, 0x12b7, 0x12be, 0x12bf, 0x12c0, 0x12c1, 0x12c5,
+  0x12c7, 0x12d6, 0x12d7, 0x1310, 0x1311, 0x1315, 0x1317, 0x135a,
+  0x135c, 0x137c, 0x137f, 0x1399, 0x139f, 0x13f5, 0x13f7, 0x13fd,
+  0x13ff, 0x169c, 0x169f, 0x16f8, 0x16ff, 0x170c, 0x170d, 0x1714,
+  0x171f, 0x1736, 0x173f, 0x1753, 0x175f, 0x176c, 0x176d, 0x1770,
+  0x1771, 0x1773, 0x177f, 0x17dd, 0x17df, 0x17e9, 0x17ef, 0x17f9,
+  0x17ff, 0x180d, 0x180f, 0x1819, 0x181f, 0x1878, 0x187f, 0x18aa,
+  0x18af, 0x18f5, 0x18ff, 0x191e, 0x191f, 0x192b, 0x192f, 0x193b,
+  0x193f, 0x1940, 0x1943, 0x196d, 0x196f, 0x1974, 0x197f, 0x19ab,
+  0x19af, 0x19c9, 0x19cf, 0x19da, 0x19dd, 0x1a1b, 0x1a1d, 0x1a5e,
+  0x1a5f, 0x1a7c, 0x1a7e, 0x1a89, 0x1a8f, 0x1a99, 0x1a9f, 0x1aad,
+  0x1aaf, 0x1abe, 0x1aff, 0x1b4b, 0x1b4f, 0x1b7c, 0x1b7f, 0x1bf3,
+  0x1bfb, 0x1c37, 0x1c3a, 0x1c49, 0x1c4c, 0x1c88, 0x1c8f, 0x1cba,
+  0x1cbc, 0x1cc7, 0x1ccf, 0x1cfa, 0x1cff, 0x1df9, 0x1dfa, 0x1f15,
+  0x1f17, 0x1f1d, 0x1f1f, 0x1f45, 0x1f47, 0x1f4d, 0x1f4f, 0x1f57,
+  0x1f58, 0x1f59, 0x1f5a, 0x1f5b, 0x1f5c, 0x1f5d, 0x1f5e, 0x1f7d,
+  0x1f7f, 0x1fb4, 0x1fb5, 0x1fc4, 0x1fc5, 0x1fd3, 0x1fd5, 0x1fdb,
+  0x1fdc, 0x1fef, 0x1ff1, 0x1ff4, 0x1ff5, 0x1ffe, 0x1fff, 0x200a,
+  0x200f, 0x2029, 0x202e, 0x205f, 0x206f, 0x2071, 0x2073, 0x208e,
+  0x208f, 0x209c, 0x209f, 0x20bf, 0x20cf, 0x20f0, 0x20ff, 0x218b,
+  0x218f, 0x2426, 0x243f, 0x244a, 0x245f, 0x2b73, 0x2b75, 0x2b95,
+  0x2b97, 0x2c2e, 0x2c2f, 0x2c5e, 0x2c5f, 0x2cf3, 0x2cf8, 0x2d25,
+  0x2d26, 0x2d27, 0x2d2c, 0x2d2d, 0x2d2f, 0x2d67, 0x2d6e, 0x2d70,
+  0x2d7e, 0x2d96, 0x2d9f, 0x2da6, 0x2da7, 0x2dae, 0x2daf, 0x2db6,
+  0x2db7, 0x2dbe, 0x2dbf, 0x2dc6, 0x2dc7, 0x2dce, 0x2dcf, 0x2dd6,
+  0x2dd7, 0x2dde, 0x2ddf, 0x2e4f, 0x2e7f, 0x2e99, 0x2e9a, 0x2ef3,
+  0x2eff, 0x2fd5, 0x2fef, 0x2ffb, 0x2fff, 0x303f, 0x3040, 0x3096,
+  0x3098, 0x30ff, 0x3104, 0x312f, 0x3130, 0x318e, 0x318f, 0x31ba,
+  0x31bf, 0x31e3, 0x31ef, 0x321e, 0x321f, 0x4db5, 0x4dbf, 0x9fef,
+  0x9fff, 0xa48c, 0xa48f, 0xa4c6, 0xa4cf, 0xa62b, 0xa63f, 0xa6f7,
+  0xa6ff, 0xa7bf, 0xa7c1, 0xa7c6, 0xa7f6, 0xa82b, 0xa82f, 0xa839,
+  0xa83f, 0xa877, 0xa87f, 0xa8c5, 0xa8cd, 0xa8d9, 0xa8df, 0xa953,
+  0xa95e, 0xa97c, 0xa97f, 0xa9cd, 0xa9ce, 0xa9d9, 0xa9dd, 0xa9fe,
+  0xa9ff, 0xaa36, 0xaa3f, 0xaa4d, 0xaa4f, 0xaa59, 0xaa5b, 0xaac2,
+  0xaada, 0xaaf6, 0xab00, 0xab06, 0xab08, 0xab0e, 0xab10, 0xab16,
+  0xab1f, 0xab26, 0xab27, 0xab2e, 0xab2f, 0xab67, 0xab6f, 0xabed,
+  0xabef, 0xabf9, 0xabff, 0xd7a3, 0xd7af, 0xd7c6, 0xd7ca, 0xd7fb,
+  0xf8ff, 0xfa6d, 0xfa6f, 0xfad9, 0xfaff, 0xfb06, 0xfb12, 0xfb17,
+  0xfb1c, 0xfb36, 0xfb37, 0xfb3c, 0xfb3d, 0xfb3e, 0xfb3f, 0xfb41,
+  0xfb42, 0xfb44, 0xfb45, 0xfbc1, 0xfbd2, 0xfd3f, 0xfd4f, 0xfd8f,
+  0xfd91, 0xfdc7, 0xfdef, 0xfdfd, 0xfdff, 0xfe19, 0xfe1f, 0xfe52,
+  0xfe53, 0xfe66, 0xfe67, 0xfe6b, 0xfe6f, 0xfe74, 0xfe75, 0xfefc,
+  0xff00, 0xffbe, 0xffc1, 0xffc7, 0xffc9, 0xffcf, 0xffd1, 0xffd7,
+  0xffd9, 0xffdc, 0xffdf, 0xffe6, 0xffe7, 0xffee, 0xfffb, 0xfffd,
+  0xffff, 0x1000b, 0x1000c, 0x10026, 0x10027, 0x1003a, 0x1003b, 0x1003d,
+  0x1003e, 0x1004d, 0x1004f, 0x1005d, 0x1007f, 0x100fa, 0x100ff, 0x10102,
+  0x10106, 0x10133, 0x10136, 0x1018e, 0x1018f, 0x1019b, 0x1019f, 0x101a0,
+  0x101cf, 0x101fd, 0x1027f, 0x1029c, 0x1029f, 0x102d0, 0x102df, 0x102fb,
+  0x102ff, 0x10323, 0x1032c, 0x1034a, 0x1034f, 0x1037a, 0x1037f, 0x1039d,
+  0x1039e, 0x103c3, 0x103c7, 0x103d5, 0x103ff, 0x1049d, 0x1049f, 0x104a9,
+  0x104af, 0x104d3, 0x104d7, 0x104fb, 0x104ff, 0x10527, 0x1052f, 0x10563,
+  0x1056e, 0x1056f, 0x105ff, 0x10736, 0x1073f, 0x10755, 0x1075f, 0x10767,
+  0x107ff, 0x10805, 0x10807, 0x10808, 0x10809, 0x10835, 0x10836, 0x10838,
+  0x1083b, 0x1083c, 0x1083e, 0x10855, 0x10856, 0x1089e, 0x108a6, 0x108af,
+  0x108df, 0x108f2, 0x108f3, 0x108f5, 0x108fa, 0x1091b, 0x1091e, 0x10939,
+  0x1093e, 0x1093f, 0x1097f, 0x109b7, 0x109bb, 0x109cf, 0x109d1, 0x10a03,
+  0x10a04, 0x10a06, 0x10a0b, 0x10a13, 0x10a14, 0x10a17, 0x10a18, 0x10a35,
+  0x10a37, 0x10a3a, 0x10a3e, 0x10a48, 0x10a4f, 0x10a58, 0x10a5f, 0x10a9f,
+  0x10abf, 0x10ae6, 0x10aea, 0x10af6, 0x10aff, 0x10b35, 0x10b38, 0x10b55,
+  0x10b57, 0x10b72, 0x10b77, 0x10b91, 0x10b98, 0x10b9c, 0x10ba8, 0x10baf,
+  0x10bff, 0x10c48, 0x10c7f, 0x10cb2, 0x10cbf, 0x10cf2, 0x10cf9, 0x10d27,
+  0x10d2f, 0x10d39, 0x10e5f, 0x10e7e, 0x10eff, 0x10f27, 0x10f2f, 0x10f59,
+  0x10fdf, 0x10ff6, 0x10fff, 0x1104d, 0x11051, 0x1106f, 0x1107e, 0x110bc,
+  0x110bd, 0x110c1, 0x110cf, 0x110e8, 0x110ef, 0x110f9, 0x110ff, 0x11134,
+  0x11135, 0x11146, 0x1114f, 0x11176, 0x1117f, 0x111cd, 0x111cf, 0x111df,
+  0x111e0, 0x111f4, 0x111ff, 0x11211, 0x11212, 0x1123e, 0x1127f, 0x11286,
+  0x11287, 0x11288, 0x11289, 0x1128d, 0x1128e, 0x1129d, 0x1129e, 0x112a9,
+  0x112af, 0x112ea, 0x112ef, 0x112f9, 0x112ff, 0x11303, 0x11304, 0x1130c,
+  0x1130e, 0x11310, 0x11312, 0x11328, 0x11329, 0x11330, 0x11331, 0x11333,
+  0x11334, 0x11339, 0x1133a, 0x11344, 0x11346, 0x11348, 0x1134a, 0x1134d,
+  0x1134f, 0x11350, 0x11356, 0x11357, 0x1135c, 0x11363, 0x11365, 0x1136c,
+  0x1136f, 0x11374, 0x113ff, 0x11459, 0x1145a, 0x1145b, 0x1145c, 0x1145f,
+  0x1147f, 0x114c7, 0x114cf, 0x114d9, 0x1157f, 0x115b5, 0x115b7, 0x115dd,
+  0x115ff, 0x11644, 0x1164f, 0x11659, 0x1165f, 0x1166c, 0x1167f, 0x116b8,
+  0x116bf, 0x116c9, 0x116ff, 0x1171a, 0x1171c, 0x1172b, 0x1172f, 0x1173f,
+  0x117ff, 0x1183b, 0x1189f, 0x118f2, 0x118fe, 0x118ff, 0x1199f, 0x119a7,
+  0x119a9, 0x119d7, 0x119d9, 0x119e4, 0x119ff, 0x11a47, 0x11a4f, 0x11aa2,
+  0x11abf, 0x11af8, 0x11bff, 0x11c08, 0x11c09, 0x11c36, 0x11c37, 0x11c45,
+  0x11c4f, 0x11c6c, 0x11c6f, 0x11c8f, 0x11c91, 0x11ca7, 0x11ca8, 0x11cb6,
+  0x11cff, 0x11d06, 0x11d07, 0x11d09, 0x11d0a, 0x11d36, 0x11d39, 0x11d3a,
+  0x11d3b, 0x11d3d, 0x11d3e, 0x11d47, 0x11d4f, 0x11d59, 0x11d5f, 0x11d65,
+  0x11d66, 0x11d68, 0x11d69, 0x11d8e, 0x11d8f, 0x11d91, 0x11d92, 0x11d98,
+  0x11d9f, 0x11da9, 0x11edf, 0x11ef8, 0x11fbf, 0x11ff1, 0x11ffe, 0x12399,
+  0x123ff, 0x1246e, 0x1246f, 0x12474, 0x1247f, 0x12543, 0x12fff, 0x1342e,
+  0x143ff, 0x14646, 0x167ff, 0x16a38, 0x16a3f, 0x16a5e, 0x16a5f, 0x16a69,
+  0x16a6d, 0x16a6f, 0x16acf, 0x16aed, 0x16aef, 0x16af5, 0x16aff, 0x16b45,
+  0x16b4f, 0x16b59, 0x16b5a, 0x16b61, 0x16b62, 0x16b77, 0x16b7c, 0x16b8f,
+  0x16e3f, 0x16e9a, 0x16eff, 0x16f4a, 0x16f4e, 0x16f87, 0x16f8e, 0x16f9f,
+  0x16fdf, 0x16fe3, 0x16fff, 0x187f7, 0x187ff, 0x18af2, 0x1afff, 0x1b11e,
+  0x1b14f, 0x1b152, 0x1b163, 0x1b167, 0x1b16f, 0x1b2fb, 0x1bbff, 0x1bc6a,
+  0x1bc6f, 0x1bc7c, 0x1bc7f, 0x1bc88, 0x1bc8f, 0x1bc99, 0x1bc9b, 0x1bc9f,
+  0x1cfff, 0x1d0f5, 0x1d0ff, 0x1d126, 0x1d128, 0x1d172, 0x1d17a, 0x1d1e8,
+  0x1d1ff, 0x1d245, 0x1d2df, 0x1d2f3, 0x1d2ff, 0x1d356, 0x1d35f, 0x1d378,
+  0x1d3ff, 0x1d454, 0x1d455, 0x1d49c, 0x1d49d, 0x1d49f, 0x1d4a1, 0x1d4a2,
+  0x1d4a4, 0x1d4a6, 0x1d4a8, 0x1d4ac, 0x1d4ad, 0x1d4b9, 0x1d4ba, 0x1d4bb,
+  0x1d4bc, 0x1d4c3, 0x1d4c4, 0x1d505, 0x1d506, 0x1d50a, 0x1d50c, 0x1d514,
+  0x1d515, 0x1d51c, 0x1d51d, 0x1d539, 0x1d53a, 0x1d53e, 0x1d53f, 0x1d544,
+  0x1d545, 0x1d546, 0x1d549, 0x1d550, 0x1d551, 0x1d6a5, 0x1d6a7, 0x1d7cb,
+  0x1d7cd, 0x1da8b, 0x1da9a, 0x1da9f, 0x1daa0, 0x1daaf, 0x1dfff, 0x1e006,
+  0x1e007, 0x1e018, 0x1e01a, 0x1e021, 0x1e022, 0x1e024, 0x1e025, 0x1e02a,
+  0x1e0ff, 0x1e12c, 0x1e12f, 0x1e13d, 0x1e13f, 0x1e149, 0x1e14d, 0x1e14f,
+  0x1e2bf, 0x1e2f9, 0x1e2fe, 0x1e2ff, 0x1e7ff, 0x1e8c4, 0x1e8c6, 0x1e8d6,
+  0x1e8ff, 0x1e94b, 0x1e94f, 0x1e959, 0x1e95d, 0x1e95f, 0x1ec70, 0x1ecb4,
+  0x1ed00, 0x1ed3d, 0x1edff, 0x1ee03, 0x1ee04, 0x1ee1f, 0x1ee20, 0x1ee22,
+  0x1ee23, 0x1ee24, 0x1ee26, 0x1ee27, 0x1ee28, 0x1ee32, 0x1ee33, 0x1ee37,
+  0x1ee38, 0x1ee39, 0x1ee3a, 0x1ee3b, 0x1ee41, 0x1ee42, 0x1ee46, 0x1ee47,
+  0x1ee48, 0x1ee49, 0x1ee4a, 0x1ee4b, 0x1ee4c, 0x1ee4f, 0x1ee50, 0x1ee52,
+  0x1ee53, 0x1ee54, 0x1ee56, 0x1ee57, 0x1ee58, 0x1ee59, 0x1ee5a, 0x1ee5b,
+  0x1ee5c, 0x1ee5d, 0x1ee5e, 0x1ee5f, 0x1ee60, 0x1ee62, 0x1ee63, 0x1ee64,
+  0x1ee66, 0x1ee6a, 0x1ee6b, 0x1ee72, 0x1ee73, 0x1ee77, 0x1ee78, 0x1ee7c,
+  0x1ee7d, 0x1ee7e, 0x1ee7f, 0x1ee89, 0x1ee8a, 0x1ee9b, 0x1eea0, 0x1eea3,
+  0x1eea4, 0x1eea9, 0x1eeaa, 0x1eebb, 0x1eeef, 0x1eef1, 0x1efff, 0x1f02b,
+  0x1f02f, 0x1f093, 0x1f09f, 0x1f0ae, 0x1f0b0, 0x1f0bf, 0x1f0c0, 0x1f0cf,
+  0x1f0d0, 0x1f0f5, 0x1f0ff, 0x1f10c, 0x1f10f, 0x1f16c, 0x1f16f, 0x1f1ac,
+  0x1f1e5, 0x1f202, 0x1f20f, 0x1f23b, 0x1f23f, 0x1f248, 0x1f24f, 0x1f251,
+  0x1f25f, 0x1f265, 0x1f2ff, 0x1f6d5, 0x1f6df, 0x1f6ec, 0x1f6ef, 0x1f6fa,
+  0x1f6ff, 0x1f773, 0x1f77f, 0x1f7d8, 0x1f7df, 0x1f7eb, 0x1f7ff, 0x1f80b,
+  0x1f80f, 0x1f847, 0x1f84f, 0x1f859, 0x1f85f, 0x1f887, 0x1f88f, 0x1f8ad,
+  0x1f8ff, 0x1f90b, 0x1f90c, 0x1f971, 0x1f972, 0x1f976, 0x1f979, 0x1f9a2,
+  0x1f9a4, 0x1f9aa, 0x1f9ad, 0x1f9ca, 0x1f9cc, 0x1fa53, 0x1fa5f, 0x1fa6d,
+  0x1fa6f, 0x1fa73, 0x1fa77, 0x1fa7a, 0x1fa7f, 0x1fa82, 0x1fa8f, 0x1fa95,
+  0x1ffff, 0x2a6d6, 0x2a6ff, 0x2b734, 0x2b73f, 0x2b81d, 0x2b81f, 0x2cea1,
+  0x2ceaf, 0x2ebe0, 0x2f7ff, 0x2fa1d, 0xe00ff, 0xe01ef, 0x10fffe,
+};
+
+static const bool is_printable[] = {
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1,
+  0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0,
+};
-- 
2.26.3


  parent reply	other threads:[~2023-05-31 18:06 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-31 18:06 [PATCH 0/3] Add diagram support to gcc diagnostics David Malcolm
2023-05-31 18:06 ` [PATCH 1/3] testsuite: move handle-multiline-outputs to before check for blank lines David Malcolm
2023-06-12 23:11   ` PING: " David Malcolm
2023-06-20 17:21     ` PING^2: " David Malcolm
2023-06-21 16:24       ` Mike Stump
2023-05-31 18:06 ` David Malcolm [this message]
2023-06-23 11:52   ` [PATCH 2/3] diagnostics: add support for "text art" diagrams Alex Coplan
2023-06-23 14:36     ` [PATCH] text-art: remove explicit #include of C++ standard library headers David Malcolm
2023-06-23 15:35       ` Alex Coplan
2023-06-24  1:26         ` [pushed: v2] " David Malcolm
2023-05-31 18:06 ` [PATCH 3/3] analyzer: add text-art visualizations of out-of-bounds accesses [PR106626] David Malcolm
2023-06-30 14:40   ` Martin Jambor
2023-07-20 14:47     ` [committed] Document new analyzer parameters Martin Jambor
2023-07-20 14:59       ` David Malcolm

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