[ASTImporter] Extend lookup logic in class templates
During import of a class template, lookup may find a forward
declaration and structural match falsely reports equivalency
between a forward decl and a definition. The result is that
some definitions are not imported if we had imported a forward
decl previously. This patch gives a fix.
Patch by Gabor Marton!
Differential Revision: https://reviews.llvm.org/D46353
llvm-svn: 332338
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 57d4585..d8c2259 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -4108,8 +4108,14 @@
if (auto *FoundTemplate = dyn_cast<ClassTemplateDecl>(Found)) {
if (IsStructuralMatch(D, FoundTemplate)) {
// The class templates structurally match; call it the same template.
- // FIXME: We may be filling in a forward declaration here. Handle
- // this case!
+
+ // We found a forward declaration but the class to be imported has a
+ // definition.
+ // FIXME Add this forward declaration to the redeclaration chain.
+ if (D->isThisDeclarationADefinition() &&
+ !FoundTemplate->isThisDeclarationADefinition())
+ continue;
+
Importer.Imported(D->getTemplatedDecl(),
FoundTemplate->getTemplatedDecl());
return Importer.Imported(D, FoundTemplate);