Detect when mapping a #include/#import over to a submodule ends up

hitting a submodule that was never actually created, e.g., because
that header wasn't parsed. In such cases, complain (because the
module's umbrella headers don't cover everything) and fall back to
including the header.

Later, we'll add a warning at module-build time to catch all such
cases. However, this fallback is important to eliminate assertions in
the ASTWriter when this happens.

llvm-svn: 146933

9 files changed, 44 insertions, 12 deletions

diff --git a/clang/include/clang/Basic/DiagnosticFrontendKinds.td b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
index ceef843409c..5efba22529a 100644
--- a/clang/include/clang/Basic/DiagnosticFrontendKinds.td
+++ b/clang/include/clang/Basic/DiagnosticFrontendKinds.td
@@ -139,6 +139,8 @@ def err_missing_umbrella_header : Error<
 def err_no_submodule : Error<"no submodule named %0 in module '%1'">;
 def err_no_submodule_suggest : Error<
   "no submodule named %0 in module '%1'; did you mean '%2'?">;
+def warn_missing_submodule : Warning<"missing submodule '%0'">,
+  InGroup<IncompleteUmbrella>;
 def err_module_map_temp_file : Error<
   "unable to write temporary module map file '%0'">, DefaultFatal;
 }
diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index d9c078f8806..bb88d48b38f 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -88,6 +88,7 @@ def LogicalOpParentheses: DiagGroup<"logical-op-parentheses">;
 def IgnoredQualifiers : DiagGroup<"ignored-qualifiers">;
 def : DiagGroup<"import">;
 def IncompatiblePointerTypes : DiagGroup<"incompatible-pointer-types">;
+def IncompleteUmbrella : DiagGroup<"incomplete-umbrella">;
 def : DiagGroup<"init-self">;
 def : DiagGroup<"inline">;
 def : DiagGroup<"int-to-pointer-cast">;
diff --git a/clang/include/clang/Basic/Module.h b/clang/include/clang/Basic/Module.h
index aef2db0feda..96b716e0cee 100644
--- a/clang/include/clang/Basic/Module.h
+++ b/clang/include/clang/Basic/Module.h
@@ -58,6 +58,9 @@ public:
   /// \brief The headers that are part of this module.
   llvm::SmallVector<const FileEntry *, 2> Headers;
   
+  /// \brief Whether this module was loaded from a module file.
+  unsigned IsFromModuleFile : 1;
+  
   /// \brief Whether this is a framework module.
   unsigned IsFramework : 1;
   
@@ -131,17 +134,18 @@ public:
   explicit Module(StringRef Name, SourceLocation DefinitionLoc,
                   bool IsFramework)
     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(0), Umbrella(),
-      IsFramework(IsFramework), IsExplicit(false), InferSubmodules(false),
-      InferExplicitSubmodules(false), InferExportWildcard(false),
-      NameVisibility(Hidden) { }
+      IsFromModuleFile(false), IsFramework(IsFramework), IsExplicit(false),
+      InferSubmodules(false), InferExplicitSubmodules(false),
+      InferExportWildcard(false), NameVisibility(Hidden) { }
   
   /// \brief Construct  a new module or submodule.
   Module(StringRef Name, SourceLocation DefinitionLoc, Module *Parent, 
          bool IsFramework, bool IsExplicit)
     : Name(Name), DefinitionLoc(DefinitionLoc), Parent(Parent), 
-      Umbrella(), IsFramework(IsFramework), IsExplicit(IsExplicit), 
-      InferSubmodules(false), InferExplicitSubmodules(false), 
-      InferExportWildcard(false),NameVisibility(Hidden) { }
+      Umbrella(), IsFromModuleFile(false), IsFramework(IsFramework), 
+      IsExplicit(IsExplicit), InferSubmodules(false), 
+      InferExplicitSubmodules(false), InferExportWildcard(false),
+      NameVisibility(Hidden) { }
   
   ~Module();
   
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 66238d0fc9f..12d368501ce 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1270,9 +1270,23 @@ Module *CompilerInstance::loadModule(SourceLocation ImportLoc,
   
   // Make the named module visible, if it's not already part of the module
   // we are parsing.
-  if (ModuleName != getLangOpts().CurrentModule)
+  if (ModuleName != getLangOpts().CurrentModule) {
+    if (!Module->IsFromModuleFile) {
+      // We have an umbrella header or directory that doesn't actually include
+      // all of the headers within the directory it covers. Complain about
+      // this missing submodule and recover by forgetting that we ever saw
+      // this submodule.
+      // FIXME: Should we detect this at module load time? It seems fairly
+      // expensive (and rare).
+      getDiagnostics().Report(ImportLoc, diag::warn_missing_submodule)
+        << Module->getFullModuleName()
+        << SourceRange(Path.front().second, Path.back().second);
+      
+      return 0;
+    }
     ModuleManager->makeModuleVisible(Module, Visibility);
-
+  }
+  
   // If this module import was due to an inclusion directive, create an 
   // implicit import declaration to capture it in the AST.
   if (IsInclusionDirective && hasASTContext()) {
diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 7c8bfd7e7cd..4d700aef03b 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1388,11 +1388,12 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     // If this was an #__include_macros directive, only make macros visible.
     Module::NameVisibilityKind Visibility 
       = (IncludeKind == 3)? Module::MacrosVisible : Module::AllVisible;
-    TheModuleLoader.loadModule(IncludeTok.getLocation(), Path, Visibility,
-                               /*IsIncludeDirective=*/true);
+    Module *Imported
+      = TheModuleLoader.loadModule(IncludeTok.getLocation(), Path, Visibility,
+                                   /*IsIncludeDirective=*/true);
     
     // If this header isn't part of the module we're building, we're done.
-    if (!BuildingImportedModule)
+    if (!BuildingImportedModule && Imported)
       return;
   }
   
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 1efc95408b3..9fc2962d27c 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3086,6 +3086,7 @@ ASTReader::ASTReadResult ASTReader::ReadSubmoduleBlock(ModuleFile &F) {
         return Failure;
       }
       
+      CurrentModule->IsFromModuleFile = true;
       CurrentModule->InferSubmodules = InferSubmodules;
       CurrentModule->InferExplicitSubmodules = InferExplicitSubmodules;
       CurrentModule->InferExportWildcard = InferExportWildcard;
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index 1776b97bb03..6883dbe3294 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1877,7 +1877,6 @@ void ASTWriter::WriteSubmodules(Module *WritingModule) {
   for (ASTContext::import_iterator I = Context->local_import_begin(),
                                 IEnd = Context->local_import_end();
        I != IEnd; ++I) {
-    assert(SubmoduleIDs.find(I->getImportedModule()) != SubmoduleIDs.end());
     if (Module *ImportedFrom
           = ModMap.inferModuleFromLocation(FullSourceLoc(I->getLocation(), 
                                                          SrcMgr))) {
diff --git a/clang/test/Modules/Inputs/Module.framework/Headers/NotInModule.h b/clang/test/Modules/Inputs/Module.framework/Headers/NotInModule.h
new file mode 100644
index 00000000000..6b15791eb2c
--- /dev/null
+++ b/clang/test/Modules/Inputs/Module.framework/Headers/NotInModule.h
@@ -0,0 +1 @@
+int not_in_module;
diff --git a/clang/test/Modules/auto-module-import.m b/clang/test/Modules/auto-module-import.m
index 21e79687610..d14f9e90304 100644
--- a/clang/test/Modules/auto-module-import.m
+++ b/clang/test/Modules/auto-module-import.m
@@ -62,3 +62,12 @@ int getModulePrivate() { return module_private; }
 int getNoUmbrellaAPrivate() { return no_umbrella_A_private; }
 
 int getNoUmbrellaBPrivateFail() { return no_umbrella_B_private; } // expected-error{{use of undeclared identifier 'no_umbrella_B_private'; did you mean 'no_umbrella_A_private'?}}
+
+// Test inclusion of headers that are under an umbrella directory but
+// not actually part of the module.
+#include <Module/NotInModule.h> // expected-warning{{treating #include as an import of module 'Module.NotInModule'}} \
+  // expected-warning{{missing submodule 'Module.NotInModule'}}
+
+int getNotInModule() {
+  return not_in_module;
+}