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-rw-r--r--clang/lib/AST/VTableBuilder.cpp13
-rw-r--r--clang/lib/CodeGen/CGVTables.cpp10
-rw-r--r--clang/lib/Sema/SemaDeclCXX.cpp24
-rw-r--r--clang/test/CodeGenCXX/microsoft-abi-extern-template.cpp25
-rw-r--r--clang/test/CodeGenCXX/microsoft-abi-vbtables.cpp2
-rw-r--r--clang/test/CodeGenCXX/microsoft-abi-vftables.cpp8
6 files changed, 55 insertions, 27 deletions
diff --git a/clang/lib/AST/VTableBuilder.cpp b/clang/lib/AST/VTableBuilder.cpp
index e43acc4de78..640fbf47aea 100644
--- a/clang/lib/AST/VTableBuilder.cpp
+++ b/clang/lib/AST/VTableBuilder.cpp
@@ -2545,14 +2545,13 @@ public:
MostDerivedClassLayout(Context.getASTRecordLayout(MostDerivedClass)),
WhichVFPtr(*Which),
Overriders(MostDerivedClass, CharUnits(), MostDerivedClass) {
- // Only include the RTTI component if we know that we will provide a
- // definition of the vftable. We always provide the definition of
- // dllimported classes.
+ // Provide the RTTI component if RTTIData is enabled. If the vftable would
+ // be available externally, we should not provide the RTTI componenent. It
+ // is currently impossible to get available externally vftables with either
+ // dllimport or extern template instantiations, but eventually we may add a
+ // flag to support additional devirtualization that needs this.
if (Context.getLangOpts().RTTIData)
- if (MostDerivedClass->hasAttr<DLLImportAttr>() ||
- MostDerivedClass->getTemplateSpecializationKind() !=
- TSK_ExplicitInstantiationDeclaration)
- HasRTTIComponent = true;
+ HasRTTIComponent = true;
LayoutVFTable();
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 83974e0d214..95705503389 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -794,6 +794,10 @@ CodeGenModule::getVTableLinkage(const CXXRecordDecl *RD) {
return DiscardableODRLinkage;
case TSK_ExplicitInstantiationDeclaration:
+ // Explicit instantiations in MSVC do not provide vtables, so we must emit
+ // our own.
+ if (getTarget().getCXXABI().isMicrosoft())
+ return DiscardableODRLinkage;
return shouldEmitAvailableExternallyVTable(*this, RD)
? llvm::GlobalVariable::AvailableExternallyLinkage
: llvm::GlobalVariable::ExternalLinkage;
@@ -839,9 +843,9 @@ CodeGenVTables::GenerateClassData(const CXXRecordDecl *RD) {
bool CodeGenVTables::isVTableExternal(const CXXRecordDecl *RD) {
assert(RD->isDynamicClass() && "Non-dynamic classes have no VTable.");
- // We always synthesize vtables on the import side regardless of whether or
- // not it is an explicit instantiation declaration.
- if (CGM.getTarget().getCXXABI().isMicrosoft() && RD->hasAttr<DLLImportAttr>())
+ // We always synthesize vtables if they are needed in the MS ABI. MSVC doesn't
+ // emit them even if there is an explicit template instantiation.
+ if (CGM.getTarget().getCXXABI().isMicrosoft())
return false;
// If we have an explicit instantiation declaration (and not a
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index d8bb3d0d958..948ad5fa9c4 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -13425,20 +13425,18 @@ void Sema::MarkVTableUsed(SourceLocation Loc, CXXRecordDecl *Class,
// checks (i.e. operator delete() lookup) when the vtable is marked used, as
// the deleting destructor is emitted with the vtable, not with the
// destructor definition as in the Itanium ABI.
- // If it has a definition, we do the check at that point instead.
if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
- if (Class->hasUserDeclaredDestructor() &&
- !Class->getDestructor()->isDefined() &&
- !Class->getDestructor()->isDeleted()) {
- CXXDestructorDecl *DD = Class->getDestructor();
- ContextRAII SavedContext(*this, DD);
- CheckDestructor(DD);
- } else if (Class->hasAttr<DLLImportAttr>()) {
- // We always synthesize vtables on the import side. To make sure
- // CheckDestructor gets called, mark the destructor referenced.
- assert(Class->getDestructor() &&
- "The destructor has always been declared on a dllimport class");
- MarkFunctionReferenced(Loc, Class->getDestructor());
+ CXXDestructorDecl *DD = Class->getDestructor();
+ if (DD && DD->isVirtual() && !DD->isDeleted()) {
+ if (Class->hasUserDeclaredDestructor() && !DD->isDefined()) {
+ // If this is an out-of-line declaration, marking it referenced will
+ // not do anything. Manually call CheckDestructor to look up operator
+ // delete().
+ ContextRAII SavedContext(*this, DD);
+ CheckDestructor(DD);
+ } else {
+ MarkFunctionReferenced(Loc, Class->getDestructor());
+ }
}
}
}
diff --git a/clang/test/CodeGenCXX/microsoft-abi-extern-template.cpp b/clang/test/CodeGenCXX/microsoft-abi-extern-template.cpp
new file mode 100644
index 00000000000..de46d5b5c37
--- /dev/null
+++ b/clang/test/CodeGenCXX/microsoft-abi-extern-template.cpp
@@ -0,0 +1,25 @@
+// RUN: %clang_cc1 -fno-rtti-data -O1 -disable-llvm-optzns %s -emit-llvm -o - -triple x86_64-windows-msvc | FileCheck %s
+
+// Even though Foo<int> has an extern template declaration, we have to emit our
+// own copy the vftable when emitting the available externally constructor.
+
+// CHECK: @"\01??_7?$Foo@H@@6B@" = linkonce_odr unnamed_addr constant [1 x i8*] [
+// CHECK-SAME: i8* bitcast (i8* (%struct.Foo*, i32)* @"\01??_G?$Foo@H@@UEAAPEAXI@Z" to i8*)
+// CHECK-SAME: ], comdat
+
+// CHECK-LABEL: define %struct.Foo* @"\01?f@@YAPEAU?$Foo@H@@XZ"()
+// CHECK: call %struct.Foo* @"\01??0?$Foo@H@@QEAA@XZ"(%struct.Foo* %{{.*}})
+
+// CHECK: define available_externally %struct.Foo* @"\01??0?$Foo@H@@QEAA@XZ"(%struct.Foo* returned %this)
+// CHECK: store {{.*}} @"\01??_7?$Foo@H@@6B@"
+
+// CHECK: define linkonce_odr i8* @"\01??_G?$Foo@H@@UEAAPEAXI@Z"(%struct.Foo* %this, i32 %should_call_delete)
+
+struct Base {
+ virtual ~Base();
+};
+template <typename T> struct Foo : Base {
+ Foo() {}
+};
+extern template class Foo<int>;
+Foo<int> *f() { return new Foo<int>(); }
diff --git a/clang/test/CodeGenCXX/microsoft-abi-vbtables.cpp b/clang/test/CodeGenCXX/microsoft-abi-vbtables.cpp
index 9cce6f8698c..df068942387 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-vbtables.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-vbtables.cpp
@@ -537,5 +537,5 @@ template <class> struct B : virtual A {
extern template class B<int>;
template B<int>::B();
-// CHECK-DAG: @"\01??_8?$B@H@Test30@@7B@" = external unnamed_addr constant [2 x i32]{{$}}
+// CHECK-DAG: @"\01??_8?$B@H@Test30@@7B@" = linkonce_odr unnamed_addr constant [2 x i32] [i32 0, i32 4], comdat
}
diff --git a/clang/test/CodeGenCXX/microsoft-abi-vftables.cpp b/clang/test/CodeGenCXX/microsoft-abi-vftables.cpp
index d94c9c1a909..0c9b58bbb4d 100644
--- a/clang/test/CodeGenCXX/microsoft-abi-vftables.cpp
+++ b/clang/test/CodeGenCXX/microsoft-abi-vftables.cpp
@@ -33,7 +33,7 @@ struct __declspec(dllexport) V {
namespace {
struct W {
- virtual ~W();
+ virtual ~W() {}
} w;
}
// RTTI-DAG: [[VTABLE_W:@.*]] = private unnamed_addr constant [2 x i8*] [i8* bitcast ({{.*}} @"\01??_R4W@?A@@6B@" to i8*), i8* bitcast ({{.*}} @"\01??_GW@?A@@UAEPAXI@Z" to i8*)]
@@ -49,5 +49,7 @@ template <class> struct Y : virtual X {
extern template class Y<int>;
template Y<int>::Y();
-// RTTI-DAG: @"\01??_7?$Y@H@@6B@" = external unnamed_addr constant [1 x i8*]
-// NO-RTTI-DAG: @"\01??_7?$Y@H@@6B@" = external unnamed_addr constant [1 x i8*]
+// RTTI-DAG: [[VTABLE_Y:@.*]] = private unnamed_addr constant [2 x i8*] [i8* bitcast (%rtti.CompleteObjectLocator* @"\01??_R4?$Y@H@@6B@" to i8*), i8* bitcast (i8* (%struct.Y*, i32)* @"\01??_G?$Y@H@@UAEPAXI@Z" to i8*)], comdat($"\01??_7?$Y@H@@6B@")
+// RTTI-DAG: @"\01??_7?$Y@H@@6B@" = unnamed_addr alias i8*, getelementptr inbounds ([2 x i8*], [2 x i8*]* [[VTABLE_Y]], i32 0, i32 1)
+
+// NO-RTTI-DAG: @"\01??_7?$Y@H@@6B@" = linkonce_odr unnamed_addr constant [1 x i8*] [i8* bitcast (i8* (%struct.Y*, i32)* @"\01??_G?$Y@H@@UAEPAXI@Z" to i8*)], comdat
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