From: Tom Tromey <tromey@adacore.com>
To: gdb-patches@sourceware.org
Cc: Tom Tromey <tromey@adacore.com>
Subject: [PATCH] Fix method naming bug in new DWARF indexer
Date: Thu, 21 Apr 2022 10:38:31 -0600 [thread overview]
Message-ID: <20220421163831.2582161-1-tromey@adacore.com> (raw)
Pedro pointed out that gdb-add-index is much slower with the new DWARF
indexer. He also noticed that, in some cases, the generated
.gdb_index would have the wrong fully-qualified name for a method.
I tracked this down to a bug in the indexer. If a type could have
methods but was marked as a declaration, the indexer was ignoring it.
However, this meant that the internal map to find the qualified name
was not updated for this container.
---
gdb/dwarf2/abbrev.c | 11 ++++
gdb/dwarf2/read.c | 7 ++-
gdb/testsuite/gdb.dwarf2/struct-decl.exp | 71 ++++++++++++++++++++++++
3 files changed, 87 insertions(+), 2 deletions(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/struct-decl.exp
diff --git a/gdb/dwarf2/abbrev.c b/gdb/dwarf2/abbrev.c
index 2db5ea15aca..4ca27eaa7e0 100644
--- a/gdb/dwarf2/abbrev.c
+++ b/gdb/dwarf2/abbrev.c
@@ -280,6 +280,17 @@ abbrev_table::read (struct dwarf2_section_info *section,
= (cur_abbrev->tag == DW_TAG_namespace
|| cur_abbrev->tag == DW_TAG_enumeration_type);
}
+ else if ((cur_abbrev->tag == DW_TAG_structure_type
+ || cur_abbrev->tag == DW_TAG_class_type
+ || cur_abbrev->tag == DW_TAG_union_type)
+ && cur_abbrev->has_children)
+ {
+ /* We have to record this as interesting, regardless of how
+ DW_AT_declaration is set, so that any subsequent
+ DW_AT_specification pointing at a child of this will get
+ the correct scope. */
+ cur_abbrev->interesting = true;
+ }
else if (has_hardcoded_declaration
&& (cur_abbrev->tag != DW_TAG_variable || !has_external))
cur_abbrev->interesting = false;
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index bb72e0e4791..6842408ad38 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -18097,8 +18097,11 @@ cooked_indexer::scan_attributes (dwarf2_per_cu_data *scanning_per_cu,
that is ok. Similarly, we allow an external variable without a
location; those are resolved via minimal symbols. */
if (is_declaration && !for_specification
- && (abbrev->tag != DW_TAG_variable
- || (*flags & IS_STATIC) != 0))
+ && !(abbrev->tag == DW_TAG_variable && (*flags & IS_STATIC) == 0)
+ && !((abbrev->tag == DW_TAG_class_type
+ || abbrev->tag == DW_TAG_structure_type
+ || abbrev->tag == DW_TAG_union_type)
+ && abbrev->has_children))
{
*linkage_name = nullptr;
*name = nullptr;
diff --git a/gdb/testsuite/gdb.dwarf2/struct-decl.exp b/gdb/testsuite/gdb.dwarf2/struct-decl.exp
new file mode 100644
index 00000000000..7d7ba52319b
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/struct-decl.exp
@@ -0,0 +1,71 @@
+# Copyright 2022 Free Software Foundation, Inc.
+
+# This program 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 of the License, or
+# (at your option) any later version.
+#
+# This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
+
+load_lib dwarf.exp
+
+# This test can only be run on targets which support DWARF-2 and use gas.
+if {![dwarf2_support]} {
+ return 0
+}
+
+standard_testfile main.c -debug.S
+
+# Set up the DWARF for the test.
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcfile
+
+ cu {} {
+ DW_TAG_compile_unit {
+ {DW_AT_language @DW_LANG_C_plus_plus}
+ {DW_AT_name $srcfile}
+ {DW_AT_comp_dir /tmp}
+
+ } {
+ declare_labels origin
+
+ # The new indexer was ignoring types that were marked as
+ # declarations, even if they could contain methods --
+ # which meant that if a method referred back to them via a
+ # specification, it would get the wrong name.
+ DW_TAG_structure_type {
+ {DW_AT_byte_size 8 DW_FORM_sdata}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name the_type}
+ {DW_AT_declaration 1 DW_FORM_flag_present}
+ } {
+ origin: DW_TAG_subprogram {
+ {DW_AT_name "method"}
+ {DW_AT_declaration 1 DW_FORM_flag_present}
+ }
+ }
+
+ # The low and high PC are phony: we just need an address
+ # range that is valid in the program, so we use the main
+ # function's range.
+ DW_TAG_subprogram {
+ {DW_AT_specification :$origin}
+ {MACRO_AT_range main}
+ }
+ }
+ }
+}
+
+if {[prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}]} {
+ return -1
+}
+
+gdb_breakpoint "the_type::method" message
--
2.34.1
next reply other threads:[~2022-04-21 16:38 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-21 16:38 Tom Tromey [this message]
2022-04-22 12:19 ` Pedro Alves
2022-04-22 12:41 ` Tom Tromey
2022-04-25 18:27 ` Tom Tromey
2022-04-26 18:40 ` Pedro Alves
2022-04-29 19:47 ` Tom Tromey
2022-05-02 14:18 ` Pedro Alves
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