Author: Hans Wennborg Date: 2022-02-04T16:31:51+01:00 New Revision: 853e0aa424e40b80d0bda1dd8a3471a361048e4b
URL: https://github.com/llvm/llvm-project/commit/853e0aa424e40b80d0bda1dd8a3471a361048e4b DIFF: https://github.com/llvm/llvm-project/commit/853e0aa424e40b80d0bda1dd8a3471a361048e4b.diff LOG: Don't dllexport reference temporaries Even if the reference itself is dllexport, the temporary should not be. In fact, we're already giving it internal linkage, so dllexporting it is not just wasteful, but will fail to link, as in the example below: $ cat /tmp/a.cc void _DllMainCRTStartup() {} const int __declspec(dllexport) &foo = 42; $ clang-cl -fuse-ld=lld /tmp/a.cc /Zl /link /dll /out:a.dll lld-link: error: <root>: undefined symbol: int const &foo::$RT1 Differential revision: https://reviews.llvm.org/D118980 Added: clang/test/CodeGenCXX/reference-temporary-ms.cpp Modified: clang/lib/CodeGen/CodeGenModule.cpp Removed: ################################################################################ diff --git a/clang/lib/CodeGen/CodeGenModule.cpp b/clang/lib/CodeGen/CodeGenModule.cpp index 2346176a15628..5ffb954642a6b 100644 --- a/clang/lib/CodeGen/CodeGenModule.cpp +++ b/clang/lib/CodeGen/CodeGenModule.cpp @@ -5725,6 +5725,9 @@ ConstantAddress CodeGenModule::GetAddrOfGlobalTemporary( /*InsertBefore=*/nullptr, llvm::GlobalVariable::NotThreadLocal, TargetAS); if (emitter) emitter->finalize(GV); setGVProperties(GV, VD); + if (GV->getDLLStorageClass() == llvm::GlobalVariable::DLLExportStorageClass) + // The reference temporary should never be dllexport. + GV->setDLLStorageClass(llvm::GlobalVariable::DefaultStorageClass); GV->setAlignment(Align.getAsAlign()); if (supportsCOMDAT() && GV->isWeakForLinker()) GV->setComdat(TheModule.getOrInsertComdat(GV->getName())); diff --git a/clang/test/CodeGenCXX/reference-temporary-ms.cpp b/clang/test/CodeGenCXX/reference-temporary-ms.cpp new file mode 100644 index 0000000000000..dd12ad8ec59f9 --- /dev/null +++ b/clang/test/CodeGenCXX/reference-temporary-ms.cpp @@ -0,0 +1,8 @@ +// RUN: %clang_cc1 -emit-llvm %s -o - -triple=i386-pc-win32 -fms-extensions | FileCheck %s + +const int __declspec(dllexport) &Exported = 42; + +// The reference temporary shouldn't be dllexport, even if the reference is. +// CHECK: @"?$RT1@Exported@@3ABHB" = internal constant i32 42 + +// CHECK: @"?Exported@@3ABHB" = dso_local dllexport constant i32* @"?$RT1@Exported@@3ABHB" _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
