[Bug debug/101431] gcc-generated DWARF5 .debug_line directory entries violate the DWARF5 spec

[roc at ocallahan dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101431

--- Comment #1 from roc at ocallahan dot org <roc at ocallahan dot org> ---
Clang follows the spec (clang 12, -fdebug-default-version=5):

The Directory Table:
  0 /tmp/pernosco-submit-test
  1 out

The File Name Table
  Entry Dir     Time    Size    MD5                                     Name
  0     0       0       0       F596F6F042BF2AD9E2B1C6B62633739A       
out/file.c
  1     1       0       0       5E2CEC2A6335E978DEB5A35D865C41E2       
message.h

So I'm not sure what to do anymore when consuming DWARF5 line number
information.

I guess we could try "treat all relative directory entries as relative to the
DW_AT_comp_dir" and hope that clang's directory entry 0 always matches
DW_AT_comp_dir...