[clang] a088766 - [dllexport] Instantiate default ctor default args for explicit specializations (PR45811)
Hans Wennborg via cfe-commits
cfe-commits at lists.llvm.org
Thu Nov 12 04:35:40 PST 2020
Author: Hans Wennborg
Date: 2020-11-12T13:29:34+01:00
New Revision: a088766508aa1a5b6e655a239546f1a64e96eb11
URL: https://github.com/llvm/llvm-project/commit/a088766508aa1a5b6e655a239546f1a64e96eb11
DIFF: https://github.com/llvm/llvm-project/commit/a088766508aa1a5b6e655a239546f1a64e96eb11.diff
LOG: [dllexport] Instantiate default ctor default args for explicit specializations (PR45811)
For dllexported default constructors with default arguments, we export
default constructor closures which pass in the default args. (See D8331
for a good explanation.)
For templates, that means those default args must be instantiated even
if the function isn't called. That is done by the
InstantiateDefaultCtorDefaultArgs() function, but it wasn't done for
explicit specializations, causing asserts (see bug).
Differential revision: https://reviews.llvm.org/D91089
Added:
Modified:
clang/include/clang/Sema/Sema.h
clang/lib/CodeGen/MicrosoftCXXABI.cpp
clang/lib/Sema/SemaDecl.cpp
clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
clang/test/CodeGenCXX/dllexport-ctor-closure.cpp
clang/test/SemaCXX/dllexport.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h
index 83d2a3122110..fb95b8cbd193 100644
--- a/clang/include/clang/Sema/Sema.h
+++ b/clang/include/clang/Sema/Sema.h
@@ -9253,6 +9253,8 @@ class Sema final {
LateInstantiatedAttrVec *LateAttrs = nullptr,
LocalInstantiationScope *OuterMostScope = nullptr);
+ void InstantiateDefaultCtorDefaultArgs(CXXConstructorDecl *Ctor);
+
bool usesPartialOrExplicitSpecialization(
SourceLocation Loc, ClassTemplateSpecializationDecl *ClassTemplateSpec);
diff --git a/clang/lib/CodeGen/MicrosoftCXXABI.cpp b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
index 31e7e4c66901..8046b7afce57 100644
--- a/clang/lib/CodeGen/MicrosoftCXXABI.cpp
+++ b/clang/lib/CodeGen/MicrosoftCXXABI.cpp
@@ -1244,12 +1244,14 @@ void MicrosoftCXXABI::EmitCXXConstructors(const CXXConstructorDecl *D) {
// the typical calling convention and have a single 'this' pointer for an
// argument -or- they get a wrapper function which appropriately thunks to the
// real default constructor. This thunk is the default constructor closure.
- if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor())
+ if (D->hasAttr<DLLExportAttr>() && D->isDefaultConstructor() &&
+ D->isDefined()) {
if (!hasDefaultCXXMethodCC(getContext(), D) || D->getNumParams() != 0) {
llvm::Function *Fn = getAddrOfCXXCtorClosure(D, Ctor_DefaultClosure);
Fn->setLinkage(llvm::GlobalValue::WeakODRLinkage);
CGM.setGVProperties(Fn, D);
}
+ }
}
void MicrosoftCXXABI::EmitVBPtrStores(CodeGenFunction &CGF,
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 02dfbd41023c..4f054e9f1ebf 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13994,6 +13994,16 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D,
FD->setInvalidDecl();
}
+ if (auto *Ctor = dyn_cast<CXXConstructorDecl>(FD)) {
+ if (Ctor->getTemplateSpecializationKind() == TSK_ExplicitSpecialization &&
+ Ctor->isDefaultConstructor() &&
+ Context.getTargetInfo().getCXXABI().isMicrosoft()) {
+ // If this is an MS ABI dllexport default constructor, instantiate any
+ // default arguments.
+ InstantiateDefaultCtorDefaultArgs(Ctor);
+ }
+ }
+
// See if this is a redefinition. If 'will have body' (or similar) is already
// set, then these checks were already performed when it was set.
if (!FD->willHaveBody() && !FD->isLateTemplateParsed() &&
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 458572cb6fa3..6623e86765d1 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -715,6 +715,26 @@ void Sema::InstantiateAttrs(const MultiLevelTemplateArgumentList &TemplateArgs,
}
}
+/// In the MS ABI, we need to instantiate default arguments of dllexported
+/// default constructors along with the constructor definition. This allows IR
+/// gen to emit a constructor closure which calls the default constructor with
+/// its default arguments.
+void Sema::InstantiateDefaultCtorDefaultArgs(CXXConstructorDecl *Ctor) {
+ assert(Context.getTargetInfo().getCXXABI().isMicrosoft() &&
+ Ctor->isDefaultConstructor());
+ unsigned NumParams = Ctor->getNumParams();
+ if (NumParams == 0)
+ return;
+ DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
+ if (!Attr)
+ return;
+ for (unsigned I = 0; I != NumParams; ++I) {
+ (void)CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
+ Ctor->getParamDecl(I));
+ DiscardCleanupsInEvaluationContext();
+ }
+}
+
/// Get the previous declaration of a declaration for the purposes of template
/// instantiation. If this finds a previous declaration, then the previous
/// declaration of the instantiation of D should be an instantiation of the
@@ -4608,27 +4628,6 @@ Sema::InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD,
return cast_or_null<FunctionDecl>(SubstDecl(FD, FD->getParent(), MArgs));
}
-/// In the MS ABI, we need to instantiate default arguments of dllexported
-/// default constructors along with the constructor definition. This allows IR
-/// gen to emit a constructor closure which calls the default constructor with
-/// its default arguments.
-static void InstantiateDefaultCtorDefaultArgs(Sema &S,
- CXXConstructorDecl *Ctor) {
- assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
- Ctor->isDefaultConstructor());
- unsigned NumParams = Ctor->getNumParams();
- if (NumParams == 0)
- return;
- DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
- if (!Attr)
- return;
- for (unsigned I = 0; I != NumParams; ++I) {
- (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
- Ctor->getParamDecl(I));
- S.DiscardCleanupsInEvaluationContext();
- }
-}
-
/// Instantiate the definition of the given function from its
/// template.
///
@@ -4847,7 +4846,7 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
// default arguments.
if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
Ctor->isDefaultConstructor()) {
- InstantiateDefaultCtorDefaultArgs(*this, Ctor);
+ InstantiateDefaultCtorDefaultArgs(Ctor);
}
}
diff --git a/clang/test/CodeGenCXX/dllexport-ctor-closure.cpp b/clang/test/CodeGenCXX/dllexport-ctor-closure.cpp
index 72d674dae7c0..a6b87c8711af 100644
--- a/clang/test/CodeGenCXX/dllexport-ctor-closure.cpp
+++ b/clang/test/CodeGenCXX/dllexport-ctor-closure.cpp
@@ -50,6 +50,14 @@ template struct __declspec(dllexport) TemplateWithClosure<int>;
// CHECK-LABEL: define weak_odr dso_local dllexport x86_thiscallcc void @"??_F?$TemplateWithClosure at H@@QAEXXZ"({{.*}}) {{#[0-9]+}} comdat
// CHECK: call {{.*}} @"??0?$TemplateWithClosure at H@@QAE at H@Z"({{.*}}, i32 4)
+template <typename T> struct __declspec(dllexport) ExportedTemplateWithClosure {
+ ExportedTemplateWithClosure(int x = sizeof(T)) {}
+};
+template <> ExportedTemplateWithClosure<int>::ExportedTemplateWithClosure(int); // Don't try to emit the closure for a declaration.
+template <> ExportedTemplateWithClosure<int>::ExportedTemplateWithClosure(int) {};
+// CHECK-LABEL: define weak_odr dso_local dllexport x86_thiscallcc void @"??_F?$ExportedTemplateWithClosure at H@@QAEXXZ"({{.*}}) {{#[0-9]+}} comdat
+// CHECK: call {{.*}} @"??0?$ExportedTemplateWithClosure at H@@QAE at H@Z"({{.*}}, i32 4)
+
struct __declspec(dllexport) NestedOuter {
DELETE_IMPLICIT_MEMBERS(NestedOuter);
NestedOuter(void *p = 0) {}
diff --git a/clang/test/SemaCXX/dllexport.cpp b/clang/test/SemaCXX/dllexport.cpp
index cef2f13cac42..820992212d9b 100644
--- a/clang/test/SemaCXX/dllexport.cpp
+++ b/clang/test/SemaCXX/dllexport.cpp
@@ -792,6 +792,11 @@ template <typename T> struct HasDefaults2 {
};
template struct HasDefaults2<void>; // expected-note {{in instantiation of member function 'HasDefaults2<void>::HasDefaults2' requested here}}
+template <typename T> struct __declspec(dllexport) HasDefaults3 { // expected-note{{in instantiation of default function argument expression for 'HasDefaults3<void>' required here}}
+ HasDefaults3(int x = sizeof(T)) {} // expected-error {{invalid application of 'sizeof'}}
+};
+template <> HasDefaults3<void>::HasDefaults3(int) {};
+
#endif
//===----------------------------------------------------------------------===//
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