tree af8c2f71340922ea25830dd7674cca403bd41fd1
parent 72060d921de5da24cb86d5f859a7be5dd19b6601
author David Greene <david.greene@cerebras.net> 1633547408 -0700
committer Copybara-Service <copybara-worker@google.com> 1638462687 -0800

[clang] Do not duplicate "EnableSplitLTOUnit" module flag

If clang's output is set to bitcode and LTO is enabled, clang would
unconditionally add the flag to the module.  Unfortunately, if the input were a
bitcode or IR file and had the flag set, this would result in two copies of the
flag, which is illegal IR.  Guard the setting of the flag by checking whether it
already exists.  This follows existing practice for the related "ThinLTO" module
flag.

Differential Revision: https://reviews.llvm.org/D112177

GitOrigin-RevId: 53adfa8750eaf4558c41a50f699616545eb0151b