Make module self-import an error

Ideally, importing Foo.a from Foo.b would "do the right thing", but
until it does, this patch makes it an error rather than allow it to
silently be ignored.

llvm-svn: 207948

5 files changed, 21 insertions, 7 deletions

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index f46e08340cb..7c4f9883538 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6990,6 +6990,8 @@ def note_module_import_in_extern_c : Note<
 def err_module_import_not_at_top_level : Error<
   "import of module '%0' appears within %1">;
 def note_module_import_not_at_top_level : Note<"%0 begins here">;
+def err_module_self_import : Error<
+  "import of module '%0' appears within same top-level module '%1'">;
 }
 
 let CategoryName = "Documentation Issue" in {
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 76301f2a44e..d7b526b2da2 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1164,7 +1164,7 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
     Module = Known->second;    
   } else if (ModuleName == getLangOpts().CurrentModule) {
     // This is the module we're building. 
-    Module = PP->getHeaderSearchInfo().getModuleMap().findModule(ModuleName);
+    Module = PP->getHeaderSearchInfo().lookupModule(ModuleName);
     Known = KnownModules.insert(std::make_pair(Path[0].first, Module)).first;
   } else {
     // Search for a module with the given name.
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 743a8f29439..3ee1577b0ba 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -13142,6 +13142,13 @@ DeclResult Sema::ActOnModuleImport(SourceLocation AtLoc,
 
   checkModuleImportContext(*this, Mod, ImportLoc, CurContext);
 
+  // FIXME: we should support importing a submodule within a different submodule
+  // of the same top-level module. Until we do, make it an error rather than
+  // silently ignoring the import.
+  if (Mod->getTopLevelModuleName() == getLangOpts().CurrentModule)
+    Diag(ImportLoc, diag::err_module_self_import)
+        << Mod->getFullModuleName() << getLangOpts().CurrentModule;
+
   SmallVector<SourceLocation, 2> IdentifierLocs;
   Module *ModCheck = Mod;
   for (unsigned I = 0, N = Path.size(); I != N; ++I) {
diff --git a/clang/test/Modules/import-self.m b/clang/test/Modules/import-self.m
new file mode 100644
index 00000000000..68be565eaf4
--- /dev/null
+++ b/clang/test/Modules/import-self.m
@@ -0,0 +1,11 @@
+// RUN: rm -rf %t
+// RUN: not %clang_cc1 -fmodules -fmodules-cache-path=%t \
+// RUN:                -I %S/Inputs/submodules %s 2>&1 | FileCheck %s
+// CHECK: import of module 'import_self.c' appears within same top-level module 'import_self'
+
+// RUN: not %clang_cc1 -fmodules -fmodules-cache-path=%t \
+// RUN:                -I %S/Inputs/submodules -fmodule-name=import_self %s \
+// RUN:     2>&1 |  FileCheck -check-prefix=CHECK-fmodule-name %s
+// CHECK-fmodule-name: import of module 'import_self.b' appears within same top-level module 'import_self'
+
+@import import_self.b;
diff --git a/clang/test/Modules/submodules.cpp b/clang/test/Modules/submodules.cpp
index 7ef785c936c..c3b2623016a 100644
--- a/clang/test/Modules/submodules.cpp
+++ b/clang/test/Modules/submodules.cpp
@@ -26,9 +26,3 @@ hash_map<int, float> ints_to_floats; // expected-error{{declaration of 'hash_map
 @import std.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;
-extern MyTypeD import_self_test_d;