[PATCH] D59553: [LLD][ELF][DebugInfo] llvm-symbolizer shows incorrect source line info if --gc-sections used

[Paul Robinson via Phabricator via llvm-commits]

probinson added a comment.

Does this do the right thing for a 32-bit target?  64-bit is common, but not universal.

Re. the underlying DWARF issues:
I can't remember whether the DWARF committee has ever considered specifying a special value for "address does not exist" but I doubt it, because the DWARF spec states "If an entity has no associated machine code, none of these [address-related] attributes are specified." (DWARF v5 section 2.17, p.51.) So, the current position of the DWARF spec is that the linker is supposed to rewrite the DWARF, I guess.

I can imagine a couple of ways to fix this in the DWARF spec, so that linkers can be allowed to strip entities without rewriting the DWARF, but you won't get that fix until DWARF v6 which has to be years in the future.  In the meantime using "-2" is probably the simplest hack.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D59553/new/

https://reviews.llvm.org/D59553