Delay emitting members of dllexport classes until the class is fully parsed (PR23542)
This enables Clang to correctly handle code such as:
struct __declspec(dllexport) S {
int x = 42;
};
where it would otherwise error due to trying to generate the default
constructor before the in-class initializer for x has been parsed.
Differential Revision: http://reviews.llvm.org/D11850
llvm-svn: 245139
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 3bd4a23..8afa332 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -4682,6 +4682,60 @@
}
}
+static void ReferenceDllExportedMethods(Sema &S, CXXRecordDecl *Class) {
+ Attr *ClassAttr = getDLLAttr(Class);
+ if (!ClassAttr)
+ return;
+
+ assert(ClassAttr->getKind() == attr::DLLExport);
+
+ TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
+
+ if (TSK == TSK_ExplicitInstantiationDeclaration)
+ // Don't go any further if this is just an explicit instantiation
+ // declaration.
+ return;
+
+ for (Decl *Member : Class->decls()) {
+ auto *MD = dyn_cast<CXXMethodDecl>(Member);
+ if (!MD)
+ continue;
+
+ if (Member->getAttr<DLLExportAttr>()) {
+ if (MD->isUserProvided()) {
+ // Instantiate non-default class member functions ...
+
+ // .. except for certain kinds of template specializations.
+ if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
+ continue;
+
+ S.MarkFunctionReferenced(Class->getLocation(), MD);
+
+ // The function will be passed to the consumer when its definition is
+ // encountered.
+ } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
+ MD->isCopyAssignmentOperator() ||
+ MD->isMoveAssignmentOperator()) {
+ // Synthesize and instantiate non-trivial implicit methods, explicitly
+ // defaulted methods, and the copy and move assignment operators. The
+ // latter are exported even if they are trivial, because the address of
+ // an operator can be taken and should compare equal accross libraries.
+ DiagnosticErrorTrap Trap(S.Diags);
+ S.MarkFunctionReferenced(Class->getLocation(), MD);
+ if (Trap.hasErrorOccurred()) {
+ S.Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
+ << Class->getName() << !S.getLangOpts().CPlusPlus11;
+ break;
+ }
+
+ // There is no later point when we will see the definition of this
+ // function, so pass it to the consumer now.
+ S.Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
+ }
+ }
+ }
+}
+
/// \brief Check class-level dllimport/dllexport attribute.
void Sema::checkClassLevelDLLAttribute(CXXRecordDecl *Class) {
Attr *ClassAttr = getDLLAttr(Class);
@@ -4783,45 +4837,10 @@
NewAttr->setInherited(true);
Member->addAttr(NewAttr);
}
-
- if (MD && ClassExported) {
- if (TSK == TSK_ExplicitInstantiationDeclaration)
- // Don't go any further if this is just an explicit instantiation
- // declaration.
- continue;
-
- if (MD->isUserProvided()) {
- // Instantiate non-default class member functions ...
-
- // .. except for certain kinds of template specializations.
- if (TSK == TSK_ImplicitInstantiation && !ClassAttr->isInherited())
- continue;
-
- MarkFunctionReferenced(Class->getLocation(), MD);
-
- // The function will be passed to the consumer when its definition is
- // encountered.
- } else if (!MD->isTrivial() || MD->isExplicitlyDefaulted() ||
- MD->isCopyAssignmentOperator() ||
- MD->isMoveAssignmentOperator()) {
- // Synthesize and instantiate non-trivial implicit methods, explicitly
- // defaulted methods, and the copy and move assignment operators. The
- // latter are exported even if they are trivial, because the address of
- // an operator can be taken and should compare equal accross libraries.
- DiagnosticErrorTrap Trap(Diags);
- MarkFunctionReferenced(Class->getLocation(), MD);
- if (Trap.hasErrorOccurred()) {
- Diag(ClassAttr->getLocation(), diag::note_due_to_dllexported_class)
- << Class->getName() << !getLangOpts().CPlusPlus11;
- break;
- }
-
- // There is no later point when we will see the definition of this
- // function, so pass it to the consumer now.
- Consumer.HandleTopLevelDecl(DeclGroupRef(MD));
- }
- }
}
+
+ if (ClassExported)
+ DelayedDllExportClasses.push_back(Class);
}
/// \brief Perform propagation of DLL attributes from a derived class to a
@@ -9479,7 +9498,7 @@
}
}
-void Sema::ActOnFinishCXXMemberDefaultArgs(Decl *D) {
+void Sema::ActOnFinishCXXNonNestedClass(Decl *D) {
auto *RD = dyn_cast<CXXRecordDecl>(D);
// Default constructors that are annotated with __declspec(dllexport) which
@@ -9487,6 +9506,15 @@
// wrapped with a thunk called the default constructor closure.
if (RD && Context.getTargetInfo().getCXXABI().isMicrosoft())
getDefaultArgExprsForConstructors(*this, RD);
+
+ if (!DelayedDllExportClasses.empty()) {
+ // Calling ReferenceDllExportedMethods might cause the current function to
+ // be called again, so use a local copy of DelayedDllExportClasses.
+ SmallVector<CXXRecordDecl *, 4> WorkList;
+ std::swap(DelayedDllExportClasses, WorkList);
+ for (CXXRecordDecl *Class : WorkList)
+ ReferenceDllExportedMethods(*this, Class);
+ }
}
void Sema::AdjustDestructorExceptionSpec(CXXRecordDecl *ClassDecl,