[Dwarf-Discuss] What does an "<artificial>" file name mean?

[Hafiz Abid Qadeer]

On 09/11/2022 13:54, John DelSignore via Dwarf-Discuss wrote:
> Hi,
> 
> On Ubuntu 22.04, the Python 3.9 DWARF debug information has compilation units that look like this:
> 
> ? Compilation Unit @ offset 0x0:
> ?? Length:??????? 0x1a14a (32-bit)
> ?? Version:?????? 5
> ?? Unit Type:???? DW_UT_compile (1)
> ?? Abbrev Offset: 0x0
> ?? Pointer Size:? 8
> ?<0><c>: Abbrev Number: 27 (DW_TAG_compile_unit)
> ??? <d>?? DW_AT_producer??? : (indirect string, offset: 0x3a): GNU GIMPLE 11.2.0 -mtune=generic
> -march=x86-64 -g -Og -Og -Og -fno-openmp -fno-openacc -fcf-protection=full -ffat-lto-objects
> -fltrans -fno-PIE
> ??? <11>?? DW_AT_language??? : 12??? (ANSI C99)
> *??? <12>?? DW_AT_name??????? : (indirect line string, offset: 0x0): <artificial>*
> ??? <16>?? DW_AT_comp_dir??? : (indirect line string, offset: 0xd):
> /build/python3.9-gIt5iY/python3.9-3.9.14/build-debug
> ??? <1a>?? DW_AT_low_pc????? : 0x422e96
> ??? <22>?? DW_AT_high_pc???? : 0xbf8c
> ??? <2a>?? DW_AT_stmt_list?? : 0x0
> 
> Notice that the DW_AT_name attribute for the CU is "<artificial>". The .debug_line info has the same
> file name:
> 
> ?The Directory Table (offset 0x22, lines 11, columns 1):
> ? Entry??? Name
> ? 0??? (indirect line string, offset: 0xd): /build/python3.9-gIt5iY/python3.9-3.9.14/build-debug
> ...SNIP...
> 
> ?The File Name Table (offset 0x54, lines 23, columns 2):
> ? Entry??? Dir??? Name
> *? 0??? 0??? (indirect line string, offset: 0x0): <artificial>*
> ...SNIP...
> 
> Does anyone know what an "<artificial>" file name is supposed to mean?
> 
> Thanks, John D.

It probably could be lto produced unit.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65015

Thanks
Abid