[all-commits] [llvm/llvm-project] 26c90e: [TargetLowering][COFF] Only check shouldAssumeDSOL...

[Andy Lim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 26c90e1588af2d70ac7cf9b51a01ea56acd9f2cc
      https://github.com/llvm/llvm-project/commit/26c90e1588af2d70ac7cf9b51a01ea56acd9f2cc
  Author: Andy Lim <andysjlim at chromium.org>
  Date:   2026-09-21 (Mon, 21 Sep 2026)

  Changed paths:
    M llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
    M llvm/test/MC/COFF/ir-to-imgrel.ll

  Log Message:
  -----------
  [TargetLowering][COFF] Only check shouldAssumeDSOLocal on GlobalVariable in lowerRelativeReference (#225160)

In #220674, a check was added to lowerRelativeReference requiring that
LHS be dso_local to prevent image-relative relocations for dllimport
variables. However, this check was applied unconditionally to all
GlobalObjects, including functions.

On Windows COFF, dllimport functions are valid targets for
image-relative relocations because the linker provides import thunks in
the local image. In particular, MSVC C++ exception handling metadata
(ThrowInfo and CatchableType) references imported copy constructors and
destructors via image-relative offsets when throwing exception types
across DLL boundaries. Rejecting them caused compilation failures in
downstream projects like PyTorch with:
"error: symbol '__ImageBase' can not be undefined in a subtraction
expression"

Restrict the shouldAssumeDSOLocal check to GlobalVariables only.



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