Keep track of modules that have failed to build. If we encounter an

import of that module elsewhere, don't try to build the module again:
it won't work, and the experience is quite dreadful. We track this
information somewhat globally, shared among all of the related
CompilerInvocations used to build modules on-the-fly, so that a
particular Clang instance will only try to build a given module once.

Fixes <rdar://problem/12552849>.

llvm-svn: 168961

1 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/Lex/PPDirectives.cpp b/clang/lib/Lex/PPDirectives.cpp
index 50b161a1723..89490a3f232 100644
--- a/clang/lib/Lex/PPDirectives.cpp
+++ b/clang/lib/Lex/PPDirectives.cpp
@@ -1483,7 +1483,7 @@ 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;
-    Module *Imported
+    ModuleLoadResult Imported
       = TheModuleLoader.loadModule(IncludeTok.getLocation(), Path, Visibility,
                                    /*IsIncludeDirective=*/true);
     assert((Imported == 0 || Imported == SuggestedModule) &&
@@ -1498,6 +1498,13 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
       }
       return;
     }
+
+    // If we failed to find a submodule that we expected to find, we can
+    // continue. Otherwise, there's an error in the included file, so we
+    // don't want to include it.
+    if (!BuildingImportedModule && !Imported.isMissingExpected()) {
+      return;
+    }
   }
 
   if (Callbacks && SuggestedModule) {