[all-commits] [llvm/llvm-project] 5122e8: [driver][darwin] Don't use -platform_version flag ...

[Hans via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 5122e828701c88f8d53ee881bc68f3904454d154
      https://github.com/llvm/llvm-project/commit/5122e828701c88f8d53ee881bc68f3904454d154
  Author: Hans Wennborg <hans at chromium.org>
  Date:   2020-02-27 (Thu, 27 Feb 2020)

  Changed paths:
    M clang/lib/Driver/ToolChains/Darwin.cpp
    M clang/test/Driver/darwin-ld-platform-version-ios.c
    M clang/test/Driver/darwin-ld-platform-version-macos.c
    M clang/test/Driver/darwin-ld-platform-version-tvos.c
    M clang/test/Driver/darwin-ld-platform-version-watchos.c

  Log Message:
  -----------
  [driver][darwin] Don't use -platform_version flag by default (PR44813)

The code in llvmorg-10-init-12188-g25ce33a6e4f is a breaking change for
users of older linkers who don't pass a version parameter, which
prevents a drop-in clang upgrade. Old tools can't know about what future
tools will do, so as a general principle the burden should be new tools
to be compatible by default. Also, for comparison, none of the other
tests of Version within AddLinkArgs add any new behaviors unless the
version is explicitly specified. Therefore, this patch changes the
-platform_version behavior from opt-out to opt-in.

Patch by David Major!

Differential revision: https://reviews.llvm.org/D74784