dwarf: use find_abstract_instance for vars and DW_AT_specification
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)
1 file changed
