Author: pcc Date: Tue Jun 30 14:07:26 2015 New Revision: 241102 URL: http://llvm.org/viewvc/llvm-project?rev=241102&view=rev Log: CodeGen: Assign an appropriate comdat to thunks.
Previously we were not assigning a comdat to thunks in the Microsoft ABI, which would have required us to emit these functions outside of a comdat. (Due to an inconsistency in how we were emitting objects, we were getting this right most of the time, but only when compiling with function sections.) This code generator change causes us to create a comdat for each thunk. Differential Revision: http://reviews.llvm.org/D10829 Modified: cfe/trunk/lib/CodeGen/CGVTables.cpp cfe/trunk/test/CodeGenCXX/microsoft-abi-thunks.cpp Modified: cfe/trunk/lib/CodeGen/CGVTables.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGVTables.cpp?rev=241102&r1=241101&r2=241102&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGVTables.cpp (original) +++ cfe/trunk/lib/CodeGen/CGVTables.cpp Tue Jun 30 14:07:26 2015 @@ -378,9 +378,6 @@ void CodeGenFunction::GenerateThunk(llvm // Set the right linkage. CGM.setFunctionLinkage(GD, Fn); - if (CGM.supportsCOMDAT() && Fn->isWeakForLinker()) - Fn->setComdat(CGM.getModule().getOrInsertComdat(Fn->getName())); - // Set the right visibility. const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl()); setThunkVisibility(CGM, MD, Thunk, Fn); @@ -450,17 +447,18 @@ void CodeGenVTables::emitThunk(GlobalDec // expensive/sucky at the moment, so don't generate the thunk unless // we have to. // FIXME: Do something better here; GenerateVarArgsThunk is extremely ugly. - if (!UseAvailableExternallyLinkage) { - CodeGenFunction(CGM).GenerateVarArgsThunk(ThunkFn, FnInfo, GD, Thunk); - CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD, - !Thunk.Return.isEmpty()); - } + if (UseAvailableExternallyLinkage) + return; + CodeGenFunction(CGM).GenerateVarArgsThunk(ThunkFn, FnInfo, GD, Thunk); } else { // Normal thunk body generation. CodeGenFunction(CGM).GenerateThunk(ThunkFn, FnInfo, GD, Thunk); - CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD, - !Thunk.Return.isEmpty()); } + + CGM.getCXXABI().setThunkLinkage(ThunkFn, ForVTable, GD, + !Thunk.Return.isEmpty()); + if (CGM.supportsCOMDAT() && ThunkFn->isWeakForLinker()) + ThunkFn->setComdat(CGM.getModule().getOrInsertComdat(ThunkFn->getName())); } void CodeGenVTables::maybeEmitThunkForVTable(GlobalDecl GD, Modified: cfe/trunk/test/CodeGenCXX/microsoft-abi-thunks.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/microsoft-abi-thunks.cpp?rev=241102&r1=241101&r2=241102&view=diff ============================================================================== --- cfe/trunk/test/CodeGenCXX/microsoft-abi-thunks.cpp (original) +++ cfe/trunk/test/CodeGenCXX/microsoft-abi-thunks.cpp Tue Jun 30 14:07:26 2015 @@ -91,7 +91,7 @@ struct E : D { E::E() {} // Emits vftable and forces thunk generation. -// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.C* @"\01?goo@E@@QAEPAUB@@XZ" +// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.C* @"\01?goo@E@@QAEPAUB@@XZ"{{.*}} comdat // CODEGEN: call x86_thiscallcc %struct.C* @"\01?goo@E@@UAEPAUC@@XZ" // CODEGEN: getelementptr inbounds i8, i8* {{.*}}, i32 4 // CODEGEN: ret @@ -124,7 +124,7 @@ struct I : D { I::I() {} // Emits vftable and forces thunk generation. -// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.{{[BF]}}* @"\01?goo@I@@QAEPAUB@@XZ" +// CODEGEN-LABEL: define weak_odr x86_thiscallcc %struct.{{[BF]}}* @"\01?goo@I@@QAEPAUB@@XZ"{{.*}} comdat // CODEGEN: %[[ORIG_RET:.*]] = call x86_thiscallcc %struct.F* @"\01?goo@I@@UAEPAUF@@XZ" // CODEGEN: %[[ORIG_RET_i8:.*]] = bitcast %struct.F* %[[ORIG_RET]] to i8* // CODEGEN: %[[VBPTR_i8:.*]] = getelementptr inbounds i8, i8* %[[ORIG_RET_i8]], i32 4 _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
