[modules] Handle defining a class template on top of an existing imported-but-not-visible definition.
llvm-svn: 233341
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ffd2239..e9c40aa 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11297,7 +11297,8 @@
ModulePrivateLoc,
/*FriendLoc*/SourceLocation(),
TemplateParameterLists.size()-1,
- TemplateParameterLists.data());
+ TemplateParameterLists.data(),
+ SkipBody);
return Result.get();
} else {
// The "template<>" header is extraneous.
@@ -11696,8 +11697,9 @@
TSK_ExplicitSpecialization;
}
+ NamedDecl *Hidden = nullptr;
if (SkipBody && getLangOpts().CPlusPlus &&
- !hasVisibleDefinition(Def, &Def)) {
+ !hasVisibleDefinition(Def, &Hidden)) {
// There is a definition of this tag, but it is not visible. We
// explicitly make use of C++'s one definition rule here, and
// assume that this definition is identical to the hidden one
@@ -11705,8 +11707,8 @@
// use it in place of this one.
*SkipBody = true;
if (auto *Listener = getASTMutationListener())
- Listener->RedefinedHiddenDefinition(Def, KWLoc);
- Def->setHidden(false);
+ Listener->RedefinedHiddenDefinition(Hidden, KWLoc);
+ Hidden->setHidden(false);
return Def;
} else if (!IsExplicitSpecializationAfterInstantiation) {
// A redeclaration in function prototype scope in C isn't
diff --git a/clang/lib/Sema/SemaLookup.cpp b/clang/lib/Sema/SemaLookup.cpp
index 0b40618..ac7376e 100644
--- a/clang/lib/Sema/SemaLookup.cpp
+++ b/clang/lib/Sema/SemaLookup.cpp
@@ -1217,11 +1217,27 @@
/// path (by instantiating a template, you allow it to see the declarations that
/// your module can see, including those later on in your module).
bool LookupResult::isVisibleSlow(Sema &SemaRef, NamedDecl *D) {
- assert(D->isHidden() && !SemaRef.ActiveTemplateInstantiations.empty() &&
- "should not call this: not in slow case");
+ assert(D->isHidden() && "should not call this: not in slow case");
Module *DeclModule = D->getOwningModule();
assert(DeclModule && "hidden decl not from a module");
+ // If this declaration is not at namespace scope nor module-private,
+ // then it is visible if its lexical parent has a visible definition.
+ DeclContext *DC = D->getLexicalDeclContext();
+ if (!D->isModulePrivate() &&
+ DC && !DC->isFileContext() && !isa<LinkageSpecDecl>(DC)) {
+ NamedDecl *Hidden;
+ if (SemaRef.hasVisibleDefinition(cast<NamedDecl>(DC), &Hidden)) {
+ if (SemaRef.ActiveTemplateInstantiations.empty()) {
+ // Cache the fact that this declaration is implicitly visible because
+ // its parent has a visible definition.
+ D->setHidden(false);
+ }
+ return true;
+ }
+ return false;
+ }
+
// Find the extra places where we need to look.
llvm::DenseSet<Module*> &LookupModules = SemaRef.getLookupModules();
if (LookupModules.empty())
diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 805709d..c642c05 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -12,6 +12,7 @@
#include "TreeTransform.h"
#include "clang/AST/ASTConsumer.h"
#include "clang/AST/ASTContext.h"
+#include "clang/AST/ASTMutationListener.h"
#include "clang/AST/DeclFriend.h"
#include "clang/AST/DeclTemplate.h"
#include "clang/AST/Expr.h"
@@ -836,7 +837,8 @@
AccessSpecifier AS, SourceLocation ModulePrivateLoc,
SourceLocation FriendLoc,
unsigned NumOuterTemplateParamLists,
- TemplateParameterList** OuterTemplateParamLists) {
+ TemplateParameterList** OuterTemplateParamLists,
+ bool *SkipBody) {
assert(TemplateParams && TemplateParams->size() > 0 &&
"No template parameters");
assert(TUK != TUK_Reference && "Can only declare or define class templates");
@@ -993,6 +995,23 @@
// Check for redefinition of this class template.
if (TUK == TUK_Definition) {
if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
+ // If we have a prior definition that is not visible, treat this as
+ // simply making that previous definition visible.
+ NamedDecl *Hidden = nullptr;
+ if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
+ *SkipBody = true;
+ auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
+ assert(Tmpl && "original definition of a class template is not a "
+ "class template?");
+ if (auto *Listener = getASTMutationListener()) {
+ Listener->RedefinedHiddenDefinition(Hidden, KWLoc);
+ Listener->RedefinedHiddenDefinition(Tmpl, KWLoc);
+ }
+ Hidden->setHidden(false);
+ Tmpl->setHidden(false);
+ return Def;
+ }
+
Diag(NameLoc, diag::err_redefinition) << Name;
Diag(Def->getLocation(), diag::note_previous_definition);
// FIXME: Would it make sense to try to "forget" the previous