Warn about dllexported explicit class template instantiation declarations (PR22035)
Clang would previously become confused and crash here.
It does not make a lot of sense to export these, so warning seems appropriate.
MSVC will export some member functions for this kind of specializations, whereas
MinGW ignores the dllexport-edness. The latter behaviour seems better.
Differential Revision: http://reviews.llvm.org/D6984
llvm-svn: 226208
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index 54de4b9..79529d5 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -4709,15 +4709,20 @@
const bool ClassExported = ClassAttr->getKind() == attr::DLLExport;
const bool ClassImported = !ClassExported;
+ TemplateSpecializationKind TSK = Class->getTemplateSpecializationKind();
+
+ // Don't dllexport explicit class template instantiation declarations.
+ if (ClassExported && TSK == TSK_ExplicitInstantiationDeclaration) {
+ Class->dropAttr<DLLExportAttr>();
+ return;
+ }
+
// Force declaration of implicit members so they can inherit the attribute.
S.ForceDeclarationOfImplicitMembers(Class);
// FIXME: MSVC's docs say all bases must be exportable, but this doesn't
// seem to be true in practice?
- TemplateSpecializationKind TSK =
- Class->getTemplateSpecializationKind();
-
for (Decl *Member : Class->decls()) {
VarDecl *VD = dyn_cast<VarDecl>(Member);
CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(Member);
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 67c36a5..254e78f 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -7165,9 +7165,27 @@
// There are two forms of explicit instantiation: an explicit instantiation
// definition and an explicit instantiation declaration. An explicit
// instantiation declaration begins with the extern keyword. [...]
- TemplateSpecializationKind TSK
- = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
- : TSK_ExplicitInstantiationDeclaration;
+ TemplateSpecializationKind TSK = ExternLoc.isInvalid()
+ ? TSK_ExplicitInstantiationDefinition
+ : TSK_ExplicitInstantiationDeclaration;
+
+ if (TSK == TSK_ExplicitInstantiationDeclaration) {
+ // Check for dllexport class template instantiation declarations.
+ for (AttributeList *A = Attr; A; A = A->getNext()) {
+ if (A->getKind() == AttributeList::AT_DLLExport) {
+ Diag(ExternLoc,
+ diag::warn_attribute_dllexport_explicit_instantiation_decl);
+ Diag(A->getLoc(), diag::note_attribute);
+ break;
+ }
+ }
+
+ if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
+ Diag(ExternLoc,
+ diag::warn_attribute_dllexport_explicit_instantiation_decl);
+ Diag(A->getLocation(), diag::note_attribute);
+ }
+ }
// Translate the parser's template argument list in our AST format.
TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);