[all-commits] [llvm/llvm-project] 8b8088: [lld] Use -1 as tombstone value for discarded code...

[EricSL via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 8b8088ac6ca977fbce52abd50ac88ecbe08d9cb2
      https://github.com/llvm/llvm-project/commit/8b8088ac6ca977fbce52abd50ac88ecbe08d9cb2
  Author: Eric Leese <leese at google.com>
  Date:   2020-12-01 (Tue, 01 Dec 2020)

  Changed paths:
    M lld/test/wasm/debug-removed-fn.ll
    M lld/test/wasm/debuginfo.test
    M lld/wasm/InputChunks.cpp
    M lld/wasm/InputChunks.h
    M lld/wasm/InputFiles.cpp
    M lld/wasm/InputFiles.h

  Log Message:
  -----------
  [lld] Use -1 as tombstone value for discarded code ranges

Under existing behavior discarded functions are relocated to have the start pc
0. This causes problems when debugging as they typically overlap the first
function and lldb symbol resolution frequently chooses a discarded function
instead of the correct one. Using the value -1 or -2 (depending on which DWARF
section we are writing) is sufficient to prevent lldb from resolving to these
symbols.

Reviewed By: MaskRay, yurydelendik, sbc100

Differential Revision: https://reviews.llvm.org/D91803