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

Mon Apr 8 23:45:26 PDT 2019

ruiu added inline comments.

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Comment at: lld/ELF/InputSection.cpp:840
+      // UINT64_MAX has special usage in .debug_ranges.
+      // https://bugs.llvm.org/show_bug.cgi?id=41124
+      Target->relocateOne(BufLoc, Type, 0xfffffffffffffffeULL);
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avl wrote:
> ruiu wrote:
> > Where in this document can I find a description why UINT64_MAX is special? Is using UINT64_MAX-1 as an "invalid value" just a local convention of lld (i.e. are you inventing a new notion) or a common practice? Is there any more common value representing an invalid address than UINT64_MAX-1?
> It is based on the comment by @jhenderson  in start of this thread. He mentioned that -1 has issues in .debug_ranges. I would find the real description of using -1 for .debug_ranges and put here...
It's fine if -1 has a special meaning, but it doesn't necessarily mean -2 is the second best. For example, why don't you use 0? What's special about -2? Or is it just arbitrary?

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

https://reviews.llvm.org/D59553