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

Thu Mar 28 06:35:40 PDT 2019

avl marked an inline comment as done.
avl added inline comments.

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Comment at: lld/ELF/InputSection.cpp:834
       Target->relocateOne(BufLoc, Type, SignExtend64<Bits>(Sym.getVA(Addend)));
+    else
+      // If relocation points to the deleted section (-Wl,--gc-sections),
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grimar wrote:
> jhenderson wrote:
> > This will patch any non-alloc section that is relocated, not just .debug* sections. I think it should be scoped to those kinds of sections only, as it could break the behaviour for other unknown sections that people may have.
> Hmmm... I do not agree here. I think if the user's section assumes that linker resolves the relocation to a removed section as a zero, that does not seem the correct assumption to me. I doubt we should care that we switched the behavior here (or at least we probably want to know about such cases before explicitly supporting them, I think).
In some previous version of the patch there was a check for Name.startswith(".debug") which I was asked to remove because "checking the symbol name is very hacky". Would it be OK to return it here ? Or probably solution similar to https://reviews.llvm.org/D54747 would be OK ? (create a flag Debug, set it Debug = Name.startswith(".debug"), and check it here)

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  https://reviews.llvm.org/D59553/new/

https://reviews.llvm.org/D59553