From: "Martin Liška" <mliska@suse.cz>
To: binutils@sourceware.org
Subject: [PATCH] dwarf: use find_abstract_instance for vars and DW_AT_specification
Date: Sun, 7 Aug 2022 19:19:47 +0200 [thread overview]
Message-ID: <c0bb6496-00ba-b541-b588-72e2fd427772@suse.cz> (raw)
The following simple test case fails when dwz is used:
$ cat demo.C
namespace std {
enum { _S_fixed, _S_floatfield = _S_fixed };
struct {
struct {};
}
__ioinit;
}
int main() {
return 0;
}
$ g++ demo.C -g && cp a.out b.out && dwz -m xxx.so a.out b.out && objdump -S a.out >/dev/null
objdump: DWARF error: could not find variable specification at offset 0x3d3
As seen the reference is defined in xxx.so shared part:
$ eu-readelf -w -N a.out | grep -A3 -B3 3d3
decl_column (data1) 11
sibling (ref_udata) [ 387]
[ 387] variable abbrev: 30
specification (GNU_ref_alt) [ 3d3]
location (exprloc)
[ 0] addr 0x404019
[ 396] subprogram abbrev: 32
$ eu-readelf -w -N a.out | less
...
Compilation unit at offset 920:
Version: 5, Abbreviation section offset: 0, Address size: 8, Offset size: 4
Unit type: partial (3)
...
[ 3d3] variable abbrev: 31
name (strp) "__ioinit"
decl_file (data1) demo.C (10)
decl_line (data1) 6
decl_column (data1) 3
type (ref_udata) [ 3c4]
declaration (flag_present) yes
With the patch the same output is emitted as before usage of dwz.
bfd/ChangeLog:
PR 29442
* dwarf2.c (struct varinfo): Use const char * type.
(scan_unit_for_symbols): Call find_abstract_instance for
DW_AT_specification for variables that can be in a different CU
(e.g. done by dwz)
---
bfd/dwarf2.c | 22 +++++++---------------
1 file changed, 7 insertions(+), 15 deletions(-)
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 47618788513..fbe9dd2070b 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -1801,7 +1801,7 @@ struct varinfo
/* The type of this variable. */
int tag;
/* The name of the variable, if it has one. */
- char *name;
+ const char *name;
/* The address of the variable. */
bfd_vma addr;
/* Where the symbol is defined. */
@@ -4094,11 +4094,12 @@ scan_unit_for_symbols (struct comp_unit *unit)
case DW_AT_specification:
if (is_int_form (&attr) && attr.u.val)
{
- struct varinfo * spec_var;
-
- spec_var = lookup_var_by_offset (attr.u.val,
- unit->variable_table);
- if (spec_var == NULL)
+ bool is_linkage;
+ if (!find_abstract_instance (unit, &attr, 0,
+ &var->name,
+ &is_linkage,
+ &var->file,
+ &var->line))
{
_bfd_error_handler (_("DWARF error: could not find "
"variable specification "
@@ -4106,15 +4107,6 @@ scan_unit_for_symbols (struct comp_unit *unit)
(unsigned long) attr.u.val);
break;
}
-
- if (var->name == NULL)
- var->name = spec_var->name;
- if (var->file == NULL && spec_var->file != NULL)
- var->file = strdup (spec_var->file);
- if (var->line == 0)
- var->line = spec_var->line;
- if (var->sec == NULL)
- var->sec = spec_var->sec;
}
break;
--
2.37.1
next reply other threads:[~2022-08-07 17:19 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-07 17:19 Martin Liška [this message]
2022-08-08 11:06 ` Nick Clifton
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