Provide Decl::getOwningModule(), which determines the (sub)module in

which a particular declaration resides. Use this information to
customize the "definition of 'blah' must be imported from another
module" diagnostic with the module the user actually has to
import. Additionally, recover by importing that module, so we don't
complain about other names in that module.

Still TODO: coming up with decent Fix-Its for these cases, and expand
this recovery approach for other name lookup failures.

llvm-svn: 172290

5 files changed, 36 insertions, 4 deletions

diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 5dccaac0205..d8b63611fd1 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -59,6 +59,11 @@ void *Decl::AllocateDeserializedDecl(const ASTContext &Context,
   return Result;
 }
 
+Module *Decl::getOwningModuleSlow() const {
+  assert(isFromASTFile() && "Not from AST file?");
+  return getASTContext().getExternalSource()->getModule(getOwningModuleID());
+}
+
 const char *Decl::getDeclKindName() const {
   switch (DeclKind) {
   default: llvm_unreachable("Declaration not in DeclNodes.inc!");
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index f31301c6e9f..5b2be919677 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1201,3 +1201,9 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
   LastModuleImportResult = ModuleLoadResult(Module, false);
   return LastModuleImportResult;
 }
+
+void CompilerInstance::makeModuleVisible(Module *Mod,
+                                         Module::NameVisibilityKind Visibility){
+  ModuleManager->makeModuleVisible(Mod, Visibility);
+}
+
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 0cf12382207..c3a2ad11230 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -11173,6 +11173,18 @@ DeclResult Sema::ActOnModuleImport(SourceLocation AtLoc,
   return Import;
 }
 
+void Sema::createImplicitModuleImport(SourceLocation Loc, Module *Mod) {
+  // Create the implicit import declaration.
+  TranslationUnitDecl *TU = getASTContext().getTranslationUnitDecl();
+  ImportDecl *ImportD = ImportDecl::CreateImplicit(getASTContext(), TU,
+                                                   Loc, Mod, Loc);
+  TU->addDecl(ImportD);
+  Consumer.HandleImplicitImportDecl(ImportD);
+
+  // Make the module visible.
+  PP.getModuleLoader().makeModuleVisible(Mod, Module::AllVisible);
+}
+
 void Sema::ActOnPragmaRedefineExtname(IdentifierInfo* Name,
                                       IdentifierInfo* AliasName,
                                       SourceLocation PragmaLoc,
diff --git a/clang/lib/Sema/SemaType.cpp b/clang/lib/Sema/SemaType.cpp
index 60db55aff33..59c1dea8ff5 100644
--- a/clang/lib/Sema/SemaType.cpp
+++ b/clang/lib/Sema/SemaType.cpp
@@ -4392,9 +4392,14 @@ bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
       // repeating the diagnostic.
       // FIXME: Add a Fix-It that imports the corresponding module or includes
       // the header.
-      if (isSFINAEContext() || HiddenDefinitions.insert(Def)) {
-        Diag(Loc, diag::err_module_private_definition) << T;
-        Diag(Def->getLocation(), diag::note_previous_definition);
+      Module *Owner = Def->getOwningModule();
+      Diag(Loc, diag::err_module_private_definition)
+        << T << Owner->getFullModuleName();
+      Diag(Def->getLocation(), diag::note_previous_definition);
+
+      if (!isSFINAEContext()) {
+        // Recover by implicitly importing this module.
+        createImplicitModuleImport(Loc, Owner);
       }
     }
 
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index a4436d16716..986eee1c951 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -6200,7 +6200,11 @@ Module *ASTReader::getSubmodule(SubmoduleID GlobalID) {
   
   return SubmodulesLoaded[GlobalID - NUM_PREDEF_SUBMODULE_IDS];
 }
-                               
+
+Module *ASTReader::getModule(unsigned ID) {
+  return getSubmodule(ID);
+}
+
 Selector ASTReader::getLocalSelector(ModuleFile &M, unsigned LocalID) {
   return DecodeSelector(getGlobalSelectorID(M, LocalID));
 }