[PATCH] [gdb/symtab] Fix incorrect filenames with inter-CU refs
Tom de Vries
tdevries@suse.de
Mon Oct 21 15:24:05 GMT 2024
With target board unix we get:
...
$ gdb -q -batch outputs/gdb.cp/cplusfuncs/cplusfuncs \
-ex "info function operator\*"
All functions matching regular expression "operator\*":
File /home/vries/gdb/src/gdb/testsuite/gdb.cp/cplusfuncs.cc:
72: void foo::operator*(foo&);
85: void foo::operator*=(foo&);
...
but with target board cc-with-dwz-m:
...
All functions matching regular expression "operator\*":
File /usr/lib/gcc/aarch64-redhat-linux/14/include/stddef.h:
72: void foo::operator*(foo&);
85: void foo::operator*=(foo&);
...
The first operator:
...
$ c++filt _ZN3foomlERS_
foo::operator*(foo&)
...
matches address 0x410250 which is defined here in the CU in the exec:
...
<1><10f1>: Abbrev Number: 13 (DW_TAG_subprogram)
<10f2> DW_AT_specification: <alt 0x93>
<10f6> DW_AT_decl_line : 72
<10f7> DW_AT_decl_column : 7
<10f7> DW_AT_object_pointer: <0x1106>
<10f9> DW_AT_low_pc : 0x410250
<1101> DW_AT_high_pc : 32
<1102> DW_AT_frame_base : 1 byte block: 9c (DW_OP_call_frame_cfa)
<1104> DW_AT_call_all_calls: 1
...
and declared here in the PU in the .dwz file:
...
<2><93>: Abbrev Number: 20 (DW_TAG_subprogram)
<94> DW_AT_external : 1
<94> DW_AT_name : operator*
<98> DW_AT_decl_file : 2
<98> DW_AT_decl_line : 10
<99> DW_AT_decl_column : 9
<9a> DW_AT_linkage_name: _ZN3foomlERS_
<9e> DW_AT_accessibility: 1 (public)
<9e> DW_AT_declaration : 1
<9e> DW_AT_object_pointer: <0xa2>
...
When creating a new symbol for the operator, the DW_AT_decl_file attribute is
looked up, and found to be 2.
The 2 is supposed to be mapped using the PU, which has this file name table:
...
The File Name Table (offset 0x78, lines 3, columns 2):
Entry Dir Name
0 0 <dwz>
1 1 stddef.h
2 2 cplusfuncs.cc
...
Instead, it's mapped using the CU, which has this file name table:
...
The File Name Table (offset 0x34, lines 3, columns 2):
Entry Dir Name
0 1 cplusfuncs.cc
1 1 cplusfuncs.cc
2 2 stddef.h
...
This is PR symtab/30814. There's a similar PR for lto, PR symtab/25771, where
the same problem happens for two CUs.
Fix this by using the correct file name table.
Add a dwarf assembly test-case for PR25771.
Tested on aarch64-linux.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=25771
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30814
---
gdb/dwarf2/read.c | 28 ++++--
.../gdb.dwarf2/dw2-inter-cu-symbol.exp | 94 +++++++++++++++++++
gdb/testsuite/lib/dwarf.exp | 4 +
3 files changed, 120 insertions(+), 6 deletions(-)
create mode 100644 gdb/testsuite/gdb.dwarf2/dw2-inter-cu-symbol.exp
diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c
index 886d14f4896..6ac6f7c6a39 100644
--- a/gdb/dwarf2/read.c
+++ b/gdb/dwarf2/read.c
@@ -17839,10 +17839,11 @@ dwarf_lang_to_enum_language (unsigned int lang)
return language;
}
-/* Return the named attribute or NULL if not there. */
+/* Return the NAME attribute of DIE in *CU, or return NULL if not there. Also
+ return in *CU the cu in which the attribute was actually found. */
static struct attribute *
-dwarf2_attr (struct die_info *die, unsigned int name, struct dwarf2_cu *cu)
+dwarf2_attr (struct die_info *die, unsigned int name, struct dwarf2_cu **cu)
{
for (;;)
{
@@ -17862,7 +17863,7 @@ dwarf2_attr (struct die_info *die, unsigned int name, struct dwarf2_cu *cu)
break;
struct die_info *prev_die = die;
- die = follow_die_ref (die, spec, &cu);
+ die = follow_die_ref (die, spec, cu);
if (die == prev_die)
/* Self-reference, we're done. */
break;
@@ -17871,6 +17872,14 @@ dwarf2_attr (struct die_info *die, unsigned int name, struct dwarf2_cu *cu)
return NULL;
}
+/* Return the NAME attribute of DIE in CU, or return NULL if not there. */
+
+static struct attribute *
+dwarf2_attr (struct die_info *die, unsigned int name, struct dwarf2_cu *cu)
+{
+ return dwarf2_attr (die, name, &cu);
+}
+
/* Return the string associated with a string-typed attribute, or NULL if it
is either not found or is of an incorrect type. */
@@ -19037,17 +19046,24 @@ new_symbol (struct die_info *die, struct type *type, struct dwarf2_cu *cu,
if (attr != nullptr)
sym->set_line (attr->constant_value (0));
+ struct dwarf2_cu *file_cu = cu;
attr = dwarf2_attr (die,
inlined_func ? DW_AT_call_file : DW_AT_decl_file,
- cu);
+ &file_cu);
if (attr != nullptr && attr->is_nonnegative ())
{
file_name_index file_index
= (file_name_index) attr->as_nonnegative ();
struct file_entry *fe;
- if (cu->line_header != NULL)
- fe = cu->line_header->file_name_at (file_index);
+ if (file_cu->line_header == nullptr)
+ {
+ file_and_directory fnd (nullptr, nullptr);
+ handle_DW_AT_stmt_list (file_cu->dies, file_cu, fnd, {}, false);
+ }
+
+ if (file_cu->line_header != nullptr)
+ fe = file_cu->line_header->file_name_at (file_index);
else
fe = NULL;
diff --git a/gdb/testsuite/gdb.dwarf2/dw2-inter-cu-symbol.exp b/gdb/testsuite/gdb.dwarf2/dw2-inter-cu-symbol.exp
new file mode 100644
index 00000000000..1e6382e7fe7
--- /dev/null
+++ b/gdb/testsuite/gdb.dwarf2/dw2-inter-cu-symbol.exp
@@ -0,0 +1,94 @@
+# Copyright 2020 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]} {
+ verbose "Skipping $gdb_test_file_name."
+ return 0
+}
+
+standard_testfile main.c -dw.S
+
+set asm_file [standard_output_file $srcfile2]
+Dwarf::assemble $asm_file {
+ global srcdir subdir srcfile srcfile2
+ declare_labels var_label int_label L1 L2
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_C}
+ {stmt_list $L1 DW_FORM_sec_offset}
+ } {
+ tag_variable {
+ {name var1}
+ {abstract_origin %$var_label}
+ {const_value 1 DW_FORM_sdata}
+ }
+ subprogram {
+ {external 1 flag}
+ {MACRO_AT_func {main}}
+ }
+ int_label: base_type {
+ {byte_size 4 udata}
+ {encoding @DW_ATE_signed}
+ {name int}
+ }
+ }
+ }
+
+ cu {} {
+ compile_unit {
+ {language @DW_LANG_C}
+ {stmt_list $L2 DW_FORM_sec_offset}
+ } {
+ var_label: tag_variable {
+ {name "var1"}
+ {type %$int_label}
+ {decl_file 1}
+ {decl_line 1}
+ }
+ }
+ }
+
+ lines {version 2} L1 {
+ file_name "file1.c" 0
+ file_name "file2.c" 0
+ }
+
+ lines {version 2} L2 {
+ file_name "file3.c" 0
+ file_name "file4.c" 0
+ }
+}
+
+if { [prepare_for_testing "failed to prepare" ${testfile} \
+ [list $srcfile $asm_file] {nodebug}] } {
+ return -1
+}
+
+if ![runto main] {
+ return -1
+}
+
+gdb_test "p var1" " = 1"
+
+set re \
+ [multi_line \
+ "All variables matching regular expression \"var1\":" \
+ "" \
+ "File file3.c:" \
+ "1:\tstatic int var1;"]
+gdb_test "info var var1" $re
diff --git a/gdb/testsuite/lib/dwarf.exp b/gdb/testsuite/lib/dwarf.exp
index f9be6c41484..6a5afec3fc8 100644
--- a/gdb/testsuite/lib/dwarf.exp
+++ b/gdb/testsuite/lib/dwarf.exp
@@ -887,6 +887,10 @@ namespace eval Dwarf {
DW_AT_GNU_addr_base {
return DW_FORM_sec_offset
}
+ DW_AT_decl_file -
+ DW_AT_decl_line {
+ return DW_FORM_udata
+ }
}
return ""
}
base-commit: 3be7119db237a7a89775f83b37e4ec89451b6945
--
2.35.3
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