[all-commits] [llvm/llvm-project] 4e6ec0: IR Linking: Support merging Warning+Max module met...

[David Blaikie via All-commits]

  Branch: refs/heads/release/10.x
  Home:   https://github.com/llvm/llvm-project
  Commit: 4e6ec0fff658cbe29e70f46491917202baa061c0
      https://github.com/llvm/llvm-project/commit/4e6ec0fff658cbe29e70f46491917202baa061c0
  Author: David Blaikie <dblaikie at gmail.com>
  Date:   2020-02-11 (Tue, 11 Feb 2020)

  Changed paths:
    M llvm/docs/LangRef.rst
    M llvm/lib/Linker/IRMover.cpp
    A llvm/test/Linker/Inputs/module-max-warn.ll
    A llvm/test/Linker/module-max-warn.ll

  Log Message:
  -----------
  IR Linking: Support merging Warning+Max module metadata flags

Summary:
Debug Info Version was changed to use "Max" instead of "Warning" per the
original design intent - but this maxes old/new IR unlinkable, since
mismatched merge styles are a linking failure.

It seems possible/maybe reasonable to actually support the combination
of these two flags: Warn, but then use the maximum value rather than the
first value/earlier module's value.

Reviewers: tejohnson

Differential Revision: https://reviews.llvm.org/D74257

(cherry picked from commit ba9cae58bbdd41451ee67773c9d0f90a01756f12)