https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99618
--- Comment #7 from H.J. Lu <hjl.tools at gmail dot com> ---
(In reply to Jakub Jelinek from comment #6)
> For normal non-LTO debug macro we emit:
> .section .debug_macro,"",@progbits
> .Ldebug_macro0:
> .value 0x5 # DWARF macro version number
> .byte 0x2 # Flags: 32-bit, lineptr present
> .long .Ldebug_line0
> .byte 0x7 # Import
> .long .Ldebug_macro2
> ...
> .section
> .debug_macro,"G",@progbits,wm4.0.d634b2ca9ddb72f687ab125549c033d0,comdat
> .Ldebug_macro2:
> .value 0x5 # DWARF macro version number
> .byte 0 # Flags: 32-bit
> .byte 0x5 # Define macro strp
> .uleb128 0 # At line number 0
> ...
> I don't see how that is any different from the above. The intent is (and it
> has been working fine for years) that linker merges the comdat sections with
> the same hash into one, and the import relocations resolve to the start of
> that section.
Same result:
[hjl@gnu-cfl-2 pr27590]$ cat bad2.s
.section .gnu.debuglto_.debug_macro,"",@progbits
.Ldebug_macro0:
.long .Ldebug_macro2
.section .gnu.debuglto_.debug_macro,"G",@progbits,wm4,comdat
.Ldebug_macro2:
.value 0x4
[hjl@gnu-cfl-2 pr27590]$ gcc -c bad2.s
[hjl@gnu-cfl-2 pr27590]$ ld -r bad2.o bad2.o
`.gnu.debuglto_.debug_macro' referenced in section `.gnu.debuglto_.debug_macro'
of bad2.o: defined in discarded section `.gnu.debuglto_.debug_macro[wm4]' of
bad2.o
[hjl@gnu-cfl-2 pr27590]$
