maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

[dllexport] odr-use constexpr default args for constructor closures 

InstantiateDefaultCtorDefaultArgs() is supposed to mark default
constructor args as odr-used, since those args will be used when
emitting the constructor closure.

However, constexpr vars were not getting odr-used since
DoMarkVarDeclReferenced() defers them in MaybeODRUseExprs, and the code
was calling CleanupVarDeclMarking() which discarded those uses instead
of processing them.

(This came up in Chromium, crbug.com/1312086)

Differential revision: https://reviews.llvm.org/D123405
This commit is contained in:
Hans Wennborg 2022-04-08 15:54:09 +02:00
parent f018a5f6e0
commit 40ad667013
2 changed files with 8 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
View File

@ -821,7 +821,7 @@ void Sema::InstantiateDefaultCtorDefaultArgs(CXXConstructorDecl *Ctor) {
for (unsigned I = 0; I != NumParams; ++I) {
(void)CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
Ctor->getParamDecl(I));
DiscardCleanupsInEvaluationContext();
CleanupVarDeclMarking();
}
}

7
clang/test/CodeGenCXX/dllexport-ctor-closure.cpp
View File

@ -88,3 +88,10 @@ CtorClosureOutOfLine::CtorClosureOutOfLine(const HasImplicitDtor2 &v) {}
// CHECK-LABEL: define linkonce_odr dso_local x86_thiscallcc void @"??1HasImplicitDtor1@@QAE@XZ"
// CHECK-LABEL: define weak_odr dso_local dllexport x86_thiscallcc void @"??_FCtorClosureOutOfLine@@QAEXXZ"
// CHECK-LABEL: define linkonce_odr dso_local x86_thiscallcc void @"??1HasImplicitDtor2@@QAE@XZ"
struct SomeStruct {};
constexpr SomeStruct kConstexprStruct;
struct __declspec(dllexport) ConstexprDefaultArg {
ConstexprDefaultArg(SomeStruct = kConstexprStruct) {}
};
// CHECK-LABEL: define weak_odr dso_local dllexport x86_thiscallcc void @"??_FConstexprDefaultArg@@QAEXXZ"