Implement DR329. We already did the right thing here in C++98 mode, but r104014
(which implemented the DR) was disabled in C++11.
llvm-svn: 200673
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index a434e20..7b84a06 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1225,7 +1225,6 @@
/// don't make it here. This function serves two purposes:
/// 1) instantiating function templates
/// 2) substituting friend declarations
-/// FIXME: preserve function definitions in case #2
Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
TemplateParameterList *TemplateParams) {
// Check whether there is already a function template specialization for
@@ -1435,35 +1434,22 @@
PrincipalDecl->setObjectOfFriendDecl();
DC->makeDeclVisibleInContext(PrincipalDecl);
- bool queuedInstantiation = false;
+ bool QueuedInstantiation = false;
- // C++98 [temp.friend]p5: When a function is defined in a friend function
- // declaration in a class template, the function is defined at each
- // instantiation of the class template. The function is defined even if it
- // is never used.
- // C++11 [temp.friend]p4: When a function is defined in a friend function
- // declaration in a class template, the function is instantiated when the
- // function is odr-used.
- //
- // If -Wc++98-compat is enabled, we go through the motions of checking for a
- // redefinition, but don't instantiate the function.
- if ((!SemaRef.getLangOpts().CPlusPlus11 ||
- SemaRef.Diags.getDiagnosticLevel(
- diag::warn_cxx98_compat_friend_redefinition,
- Function->getLocation())
- != DiagnosticsEngine::Ignored) &&
- D->isThisDeclarationADefinition()) {
+ // C++11 [temp.friend]p4 (DR329):
+ // When a function is defined in a friend function declaration in a class
+ // template, the function is instantiated when the function is odr-used.
+ // The same restrictions on multiple declarations and definitions that
+ // apply to non-template function declarations and definitions also apply
+ // to these implicit definitions.
+ if (D->isThisDeclarationADefinition()) {
// Check for a function body.
const FunctionDecl *Definition = 0;
if (Function->isDefined(Definition) &&
Definition->getTemplateSpecializationKind() == TSK_Undeclared) {
- SemaRef.Diag(Function->getLocation(),
- SemaRef.getLangOpts().CPlusPlus11 ?
- diag::warn_cxx98_compat_friend_redefinition :
- diag::err_redefinition) << Function->getDeclName();
+ SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
+ << Function->getDeclName();
SemaRef.Diag(Definition->getLocation(), diag::note_previous_definition);
- if (!SemaRef.getLangOpts().CPlusPlus11)
- Function->setInvalidDecl();
}
// Check for redefinitions due to other instantiations of this or
// a similar friend function.
@@ -1472,36 +1458,34 @@
R != REnd; ++R) {
if (*R == Function)
continue;
- switch (R->getFriendObjectKind()) {
- case Decl::FOK_None:
- if (!SemaRef.getLangOpts().CPlusPlus11 &&
- !queuedInstantiation && R->isUsed(false)) {
- if (MemberSpecializationInfo *MSInfo
- = Function->getMemberSpecializationInfo()) {
- if (MSInfo->getPointOfInstantiation().isInvalid()) {
- SourceLocation Loc = R->getLocation(); // FIXME
- MSInfo->setPointOfInstantiation(Loc);
- SemaRef.PendingLocalImplicitInstantiations.push_back(
- std::make_pair(Function, Loc));
- queuedInstantiation = true;
- }
+
+ // If some prior declaration of this function has been used, we need
+ // to instantiate its definition.
+ if (!QueuedInstantiation && R->isUsed(false)) {
+ if (MemberSpecializationInfo *MSInfo =
+ Function->getMemberSpecializationInfo()) {
+ if (MSInfo->getPointOfInstantiation().isInvalid()) {
+ SourceLocation Loc = R->getLocation(); // FIXME
+ MSInfo->setPointOfInstantiation(Loc);
+ SemaRef.PendingLocalImplicitInstantiations.push_back(
+ std::make_pair(Function, Loc));
+ QueuedInstantiation = true;
}
}
- break;
- default:
- if (const FunctionDecl *RPattern
- = R->getTemplateInstantiationPattern())
+ }
+
+ // If some prior declaration of this function was a friend with an
+ // uninstantiated definition, reject it.
+ if (R->getFriendObjectKind()) {
+ if (const FunctionDecl *RPattern =
+ R->getTemplateInstantiationPattern()) {
if (RPattern->isDefined(RPattern)) {
- SemaRef.Diag(Function->getLocation(),
- SemaRef.getLangOpts().CPlusPlus11 ?
- diag::warn_cxx98_compat_friend_redefinition :
- diag::err_redefinition)
+ SemaRef.Diag(Function->getLocation(), diag::err_redefinition)
<< Function->getDeclName();
SemaRef.Diag(R->getLocation(), diag::note_previous_definition);
- if (!SemaRef.getLangOpts().CPlusPlus11)
- Function->setInvalidDecl();
break;
}
+ }
}
}
}