* Re: [PATCH] gdb: Support DW_LLE_start_end
2021-06-21 17:02 ` Simon Marchi
@ 2021-06-22 12:24 ` Andreas Schwab
2021-06-22 13:36 ` Simon Marchi
0 siblings, 1 reply; 4+ messages in thread
From: Andreas Schwab @ 2021-06-22 12:24 UTC (permalink / raw)
To: Simon Marchi; +Cc: gdb-patches
Without that it is impossible to debug on riscv64.
gdb/
PR symtab/27999
* dwarf2/loc.c (decode_debug_loclists_addresses): Support
DW_LLE_start_end.
gdb/testsuite/
PR symtab/27999
* lib/dwarf.exp (start_end): New proc inside loclists.
* gdb.dwarf2/loclists-start-end.exp: New file.
* gdb.dwarf2/loclists-start-end.c: New file.
---
gdb/dwarf2/loc.c | 20 ++-
gdb/testsuite/gdb.dwarf2/loclists-start-end.c | 37 +++++
.../gdb.dwarf2/loclists-start-end.exp | 137 ++++++++++++++++++
gdb/testsuite/lib/dwarf.exp | 29 ++++
4 files changed, 222 insertions(+), 1 deletion(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/loclists-start-end.c
create mode 100644 gdb/testsuite/gdb.dwarf2/loclists-start-end.exp
diff --git a/gdb/dwarf2/loc.c b/gdb/dwarf2/loc.c
index b7e30e3cb4a..d57cdc165ba 100644
--- a/gdb/dwarf2/loc.c
+++ b/gdb/dwarf2/loc.c
@@ -255,9 +255,27 @@ decode_debug_loclists_addresses (dwarf2_per_cu_data *per_cu,
*new_ptr = loc_ptr;
return DEBUG_LOC_OFFSET_PAIR;
+ case DW_LLE_start_end:
+ if (loc_ptr + 2 * addr_size > buf_end)
+ return DEBUG_LOC_BUFFER_OVERFLOW;
+
+ if (signed_addr_p)
+ *low = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ *low = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+
+ loc_ptr += addr_size;
+ if (signed_addr_p)
+ *high = extract_signed_integer (loc_ptr, addr_size, byte_order);
+ else
+ *high = extract_unsigned_integer (loc_ptr, addr_size, byte_order);
+
+ loc_ptr += addr_size;
+ *new_ptr = loc_ptr;
+ return DEBUG_LOC_START_END;
+
/* Following cases are not supported yet. */
case DW_LLE_startx_endx:
- case DW_LLE_start_end:
case DW_LLE_default_location:
default:
return DEBUG_LOC_INVALID_ENTRY;
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-start-end.c b/gdb/testsuite/gdb.dwarf2/loclists-start-end.c
new file mode 100644
index 00000000000..2bffbf2ac4c
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/loclists-start-end.c
@@ -0,0 +1,37 @@
+/* Copyright (C) 2021 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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/>. */
+
+static int
+func1 (void)
+{
+ asm ("func1_label: .global func1_label\n");
+ return 1;
+}
+
+static int
+func2 (void)
+{
+ asm ("func2_label: .global func2_label\n");
+ return 2;
+}
+
+int
+main (void)
+{
+ func1 ();
+ func2 ();
+}
diff --git a/gdb/testsuite/gdb.dwarf2/loclists-start-end.exp b/gdb/testsuite/gdb.dwarf2/loclists-start-end.exp
new file mode 100644
index 00000000000..43ddefcf61d
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/loclists-start-end.exp
@@ -0,0 +1,137 @@
+# Copyright 2021 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/>.
+
+# Test support for DW_LLE_start_end (PR symtab/27999).
+
+load_lib dwarf.exp
+
+if {![dwarf2_support]} {
+ return 0
+}
+
+# Test with 32-bit and 64-bit DWARF.
+foreach_with_prefix is_64 {false true} {
+ if { $is_64 } {
+ standard_testfile .c -dw64.S
+ set testfile ${testfile}-dw64
+ } else {
+ standard_testfile .c -dw32.S
+ set testfile ${testfile}-dw32
+ }
+
+ # Get the addresses / lengths of func1 and func2.
+ lassign [function_range func1 $srcdir/$subdir/$srcfile] func1_addr func1_len
+ lassign [function_range func2 $srcdir/$subdir/$srcfile] func2_addr func2_len
+
+ set asm_file [standard_output_file $srcfile2]
+ Dwarf::assemble $asm_file {
+ global func1_addr func1_len
+ global func2_addr func2_len
+ global is_64
+
+ # The CU uses the DW_FORM_loclistx form to refer to the .debug_loclists
+ # section.
+ cu {
+ version 5
+ is_64 $is_64
+ } {
+ declare_labels int_type
+
+ DW_TAG_compile_unit {
+ {DW_AT_loclists_base cu_table DW_FORM_sec_offset}
+ } {
+ int_type: DW_TAG_base_type {
+ {DW_AT_byte_size 4 DW_FORM_data1}
+ {DW_AT_encoding @DW_ATE_signed}
+ {DW_AT_name "int"}
+ }
+
+ DW_TAG_variable {
+ {DW_AT_name "foo"}
+ {DW_AT_location 1 DW_FORM_loclistx}
+ {DW_AT_type :$int_type}
+ }
+
+ DW_TAG_subprogram {
+ {DW_AT_name "func1"}
+ {DW_AT_low_pc $func1_addr}
+ {DW_AT_high_pc $func1_len DW_FORM_udata}
+ }
+
+ DW_TAG_subprogram {
+ {DW_AT_name "func2"}
+ {DW_AT_low_pc $func2_addr}
+ {DW_AT_high_pc $func2_len DW_FORM_udata}
+ }
+ }
+ }
+
+ loclists -is-64 $is_64 {
+ # This table is unused, but exists so that the used table is not at
+ # the beginning of the section.
+ table {
+ list_ {
+ start_end 0x1000 0x2000 { DW_OP_addr 0x100000 }
+ }
+ }
+
+ # The lists in this table are accessed by index (DW_FORM_rnglistx).
+ table -post-header-label cu_table {
+ # This list is unused, but exists to offset the next ones.
+ list_ {
+ start_end 0x1000 0x2000 { DW_OP_addr 0x100000 }
+ }
+
+ # For variable foo.
+ list_ {
+ # When in func1.
+ start_end $func1_addr "$func1_addr + $func1_len" {
+ DW_OP_constu 0x123456
+ DW_OP_stack_value
+ }
+
+ # When in func2.
+ start_end $func2_addr "$func2_addr + $func2_len" {
+ DW_OP_constu 0x234567
+ DW_OP_stack_value
+ }
+ }
+ }
+ }
+ }
+
+ if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+ }
+
+ if { ![runto_main] } {
+ fail "can't run to main"
+ return
+ }
+
+ gdb_breakpoint "func1"
+ gdb_breakpoint "func2"
+
+ gdb_continue_to_breakpoint "func1"
+ with_test_prefix "at func1" {
+ gdb_test "print /x foo" " = 0x123456"
+ }
+
+ gdb_continue_to_breakpoint "func2"
+ with_test_prefix "at func2" {
+ gdb_test "print /x foo" " = 0x234567"
+ }
+}
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index e4dc284f4ee..4e6879a2d3f 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -1849,6 +1849,35 @@ namespace eval Dwarf {
incr _debug_loclists_locdesc_count
}
+ # Emit a DW_LLE_start_end entry.
+
+ proc start_end { start end locdesc } {
+ variable _debug_loclists_is_64_dwarf
+ variable _debug_loclists_addr_size
+ variable _debug_loclists_offset_size
+ variable _debug_loclists_table_count
+ variable _debug_loclists_list_count
+ variable _debug_loclists_locdesc_count
+
+ _op .byte 0x07 "DW_LLE_start_end"
+
+ # Start and end of the address range.
+ _op .${_debug_loclists_addr_size}byte $start "start"
+ _op .${_debug_loclists_addr_size}byte $end "end"
+
+ # Length of location description.
+ set locdesc_start_label ".Lloclists_table_${_debug_loclists_table_count}_list_${_debug_loclists_list_count}_locdesc_${_debug_loclists_locdesc_count}_start"
+ set locdesc_end_label ".Lloclists_table_${_debug_loclists_table_count}_list_${_debug_loclists_list_count}_locdesc_${_debug_loclists_locdesc_count}_end"
+ _op .uleb128 "$locdesc_end_label - $locdesc_start_label" "locdesc length"
+
+ define_label $locdesc_start_label
+ set dwarf_version 5
+ _location $locdesc $dwarf_version $_debug_loclists_addr_size $_debug_loclists_offset_size
+ define_label $locdesc_end_label
+
+ incr _debug_loclists_locdesc_count
+ }
+
uplevel $body
# Emit end of list.
--
2.31.1
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."
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