[all-commits] [llvm/llvm-project] a8d3ae: [Driver] Default -fsanitize-address-globals-dead-s...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a8d3ae712290d6f85db2deb9164181058f5c1307
      https://github.com/llvm/llvm-project/commit/a8d3ae712290d6f85db2deb9164181058f5c1307
  Author: Fangrui Song <i at maskray.me>
  Date:   2023-06-12 (Mon, 12 Jun 2023)

  Changed paths:
    M clang/lib/Driver/SanitizerArgs.cpp
    M clang/test/Driver/fsanitize.c

  Log Message:
  -----------
  [Driver] Default -fsanitize-address-globals-dead-stripping to true for ELF

-fsanitize-address-globals-dead-stripping is the default for non-ELF
platforms. For ELF, we disabled it to work around an ancient gold 2.26
bug. However, some platforms (Fuchsia and PS) default the option to
true.

This patch changes -fsanitize-address-globals-dead-stripping to true for all ELF
platforms. Without specifying -fdata-sections (non-default for most ELF
platforms), `asan_globals` can only be GCed if the monolithic .data/.bss section
is GCed, which makes it less effective.
However, I think this simplified rule is better than making the
-fsanitize-address-globals-dead-stripping default dependent on another option.

Related: D120394
Close https://github.com/llvm/llvm-project/issues/63127

Reviewed By: #sanitizers, eugenis, phosek

Differential Revision: https://reviews.llvm.org/D152604