[all-commits] [llvm/llvm-project] 0fd5e7: [WebAssembly][lld] Fix segfault on .bss sections i...

[Thomas Lively via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0fd5e7b2d8ca4ed46d76187feb4b903ed0a3ea75
      https://github.com/llvm/llvm-project/commit/0fd5e7b2d8ca4ed46d76187feb4b903ed0a3ea75
  Author: Thomas Lively <tlively at google.com>
  Date:   2021-07-07 (Wed, 07 Jul 2021)

  Changed paths:
    M lld/test/wasm/map-file.s
    M lld/wasm/MapFile.cpp

  Log Message:
  -----------
  [WebAssembly][lld] Fix segfault on .bss sections in mapfile

When memory is declared in the Wasm module, we rely on the implicit zero
initialization behavior and do not explicitly output .bss sections. The means
that they do not have associated `outputSec` entries, which was causing
segfaults in the mapfile support. Fix the issue by guarding against null
`outputSec` and falling back to using a zero offset.

Differential Revision: https://reviews.llvm.org/D102951