https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107012
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I don't see anything wrong on what GCC emits.
If I compile with -O3 -g3 -gdwarf-4 -dA -nostdinc so that stdc-predef.h isn't
included vs. -O3 -g3 -gdwarf-5 -dA -nostdinc, in .debug_macro I see for DWARF
4:
.section .debug_macro,"",@progbits
.Ldebug_macro0:
.value 0x4 # DWARF macro version number
.byte 0x2 # Flags: 32-bit, lineptr present
.long .Ldebug_line0
.byte 0x7 # Import
.long .Ldebug_macro2
.byte 0x3 # Start new file
.byte 0 # uleb128 0; Included from line number 0
.byte 0x1 # uleb128 0x1; file pr107012.c
.byte 0x5 # Define macro strp
.byte 0x1 # uleb128 0x1; At line number 1
.long .LASF372 # The macro: "TEST_MACRO 42"
.byte 0x4 # End file
.byte 0 # End compilation unit
where .Ldebug_macro2 is import of the predefined macros.
.debug_line then has:
.ascii "pr107012.c\0" # File Entry: 0x1
.byte 0 # uleb128 0
.byte 0 # uleb128 0
.byte 0 # uleb128 0
i.e. file entry 1 is pr107012.c.
In DWARF 5 it is:
.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
.byte 0x3 # Start new file
.byte 0 # uleb128 0; Included from line number 0
.byte 0x1 # uleb128 0x1; file pr107012.c
.byte 0x5 # Define macro strp
.byte 0x1 # uleb128 0x1; At line number 1
.long .LASF374 # The macro: "TEST_MACRO 42"
.byte 0x4 # End file
.byte 0 # End compilation unit
so there are only minor differences related to macros:
- .long .Ldebug_macro0 # DW_AT_GNU_macros
+ .long .Ldebug_macro0 # DW_AT_macros
in .debug_info section and
.section .debug_macro,"",@progbits
.Ldebug_macro0:
- .value 0x4 # DWARF macro version number
+ .value 0x5 # DWARF macro version number
.byte 0x2 # Flags: 32-bit, lineptr present
.long .Ldebug_line0
.byte 0x7 # Import
...
.byte 0x1 # uleb128 0x1; file pr107012.c
.byte 0x5 # Define macro strp
.byte 0x1 # uleb128 0x1; At line number 1
- .long .LASF372 # The macro: "TEST_MACRO 42"
+ .long .LASF374 # The macro: "TEST_MACRO 42"
.byte 0x4 # End file
.byte 0 # End compilation unit
in .debug_macro. The line table then says that both file 0 and 1 are
pr107012.c:
.byte 0x2 # File name entry format count
.byte 0x1 # uleb128 0x1; DW_LNCT_path
.byte 0x1f # uleb128 0x1f; DW_FORM_line_strp
.byte 0x2 # uleb128 0x2; DW_LNCT_directory_index
.byte 0xb # uleb128 0xb; DW_FORM_data1
.byte 0x2 # uleb128 0x2; File names count
.long .LASF0 # File Entry: 0: "pr107012.c"
.byte 0
.long .LASF0 # File Entry: 0: "pr107012.c"
.byte 0
You'd better file this against gdb...
