If we see an explicit instantiation declaration or definition of a function

after we've already instantiated a definition for the function, pass it to the
ASTConsumer again so that it knows the specialization kind has changed and can
update the function's linkage.

This only matters if we instantiate the definition of the function before we
reach the end of the TU; this can happen in at least three different ways:
C++11 constexpr functions, C++14 deduced return types, and functions
instantiated within modules.

llvm-svn: 207152

1 files changed, 6 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 64c32638051..fb35f9084f7 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -7188,6 +7188,7 @@ Sema::ActOnExplicitInstantiation(Scope *S,
     // TSK_ExplicitInstantiationDefinition
     if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
         TSK == TSK_ExplicitInstantiationDefinition)
+      // FIXME: Need to notify the ASTMutationListener that we did this.
       Def->setTemplateSpecializationKind(TSK);
 
     InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
@@ -7624,7 +7625,11 @@ DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
   if (Attr)
     ProcessDeclAttributeList(S, Specialization, Attr);
 
-  if (TSK == TSK_ExplicitInstantiationDefinition)
+  if (Specialization->isDefined()) {
+    // Let the ASTConsumer know that this function has been explicitly
+    // instantiated now, and its linkage might have changed.
+    Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
+  } else if (TSK == TSK_ExplicitInstantiationDefinition)
     InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
 
   // C++0x [temp.explicit]p2: