Fix crash if a submodule @imports another submodule from the same module. The

test also adds FIXMEs for a number of places where imports and includes of
submodules don't work very well.

llvm-svn: 193005

clang/lib/Frontend/CompilerInstance.cpp

@@ -1108,23 +1108,23 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
                              ModuleIdPath Path,
                              Module::NameVisibilityKind Visibility,
                              bool IsInclusionDirective) {
+  // Determine what file we're searching from.
+  StringRef ModuleName = Path[0].first->getName();
+  SourceLocation ModuleNameLoc = Path[0].second;
+
   // If we've already handled this import, just return the cached result.
   // This one-element cache is important to eliminate redundant diagnostics
   // when both the preprocessor and parser see the same import declaration.
   if (!ImportLoc.isInvalid() && LastModuleImportLoc == ImportLoc) {
     // Make the named module visible.
-    if (LastModuleImportResult)
+    if (LastModuleImportResult && ModuleName != getLangOpts().CurrentModule)
       ModuleManager->makeModuleVisible(LastModuleImportResult, Visibility,
                                        ImportLoc, /*Complain=*/false);
     return LastModuleImportResult;
   }
-  
-  // Determine what file we're searching from.
-  StringRef ModuleName = Path[0].first->getName();
-  SourceLocation ModuleNameLoc = Path[0].second;
 
   clang::Module *Module = 0;
-  
+
   // If we don't already have information on this module, load the module now.
   llvm::DenseMap<const IdentifierInfo *, clang::Module *>::iterator Known
     = KnownModules.find(Path[0].first);

clang/test/Modules/Inputs/submodules/import-self-a.h

@@ -0,0 +1 @@
+typedef int MyTypeA;

clang/test/Modules/Inputs/submodules/import-self-b.h

@@ -0,0 +1,10 @@
+@import import_self.c;
+#include "import-self-d.h"
+
+// FIXME: This should not work; names from 'a' should not be visible here.
+MyTypeA import_self_test_a;
+
+// FIXME: This should work but does not; names from 'b' are not actually visible here.
+//MyTypeC import_self_test_c;
+
+MyTypeD import_self_test_d;

clang/test/Modules/Inputs/submodules/import-self-c.h

@@ -0,0 +1 @@
+typedef int MyTypeC;

clang/test/Modules/Inputs/submodules/import-self-d.h

@@ -0,0 +1 @@
+typedef int MyTypeD;

clang/test/Modules/Inputs/submodules/module.map

@@ -3,3 +3,10 @@ module std {
   module type_traits { header "type_traits.h" }
   explicit module hash_map { header "hash_map.h" }
 }
+
+module import_self {
+  module a { header "import-self-a.h" }
+  module b { header "import-self-b.h" export * }
+  module c { header "import-self-c.h" }
+  module d { header "import-self-d.h" }
+}

clang/test/Modules/submodules.cpp

@@ -27,3 +27,10 @@ hash_map<int, float> ints_to_floats; // expected-error{{declaration of 'hash_map
 
 hash_map<int, float> ints_to_floats2;
 
+@import import_self.b;
+extern MyTypeA import_self_test_a; // expected-error {{must be imported from module 'import_self.a'}}
+// expected-note@import-self-a.h:1 {{here}}
+extern MyTypeC import_self_test_c;
+// FIXME: This should be valid; import_self.b re-exports import_self.d.
+extern MyTypeD import_self_test_d; // expected-error {{must be imported from module 'import_self.d'}}
+// expected-note@import-self-d.h:1 {{here}}