From b797d59f031600ffe1eccefae60fc678ed1d0aad Mon Sep 17 00:00:00 2001
From: Ben Langmuir <blangmuir@apple.com>
Date: Sat, 19 Jul 2014 16:29:28 +0000
Subject: [PATCH] If a module build reports errors, don't try to load it

... just to find out that it didn't build.

llvm-svn: 213454
---
 clang/lib/Frontend/CompilerInstance.cpp | 34 ++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 7cea9e4..6af920d 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -852,11 +852,12 @@ static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
 }
 
 /// \brief Compile a module file for the given module, using the options 
-/// provided by the importing compiler instance.
-static void compileModuleImpl(CompilerInstance &ImportingInstance,
-                          SourceLocation ImportLoc,
-                          Module *Module,
-                          StringRef ModuleFileName) {
+/// provided by the importing compiler instance. Returns true if the module
+/// was built without errors.
+static bool compileModuleImpl(CompilerInstance &ImportingInstance,
+                              SourceLocation ImportLoc,
+                              Module *Module,
+                              StringRef ModuleFileName) {
   ModuleMap &ModMap 
     = ImportingInstance.getPreprocessor().getHeaderSearchInfo().getModuleMap();
     
@@ -979,13 +980,20 @@ static void compileModuleImpl(CompilerInstance &ImportingInstance,
   if (ImportingInstance.getFrontendOpts().GenerateGlobalModuleIndex) {
     ImportingInstance.setBuildGlobalModuleIndex(true);
   }
+
+  return !Instance.getDiagnostics().hasErrorOccurred();
 }
 
 static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
                                  SourceLocation ImportLoc,
-                                 SourceLocation ModuleNameLoc,
-                                 Module *Module,
+                                 SourceLocation ModuleNameLoc, Module *Module,
                                  StringRef ModuleFileName) {
+  auto diagnoseBuildFailure = [&] {
+    ImportingInstance.getDiagnostics().Report(ModuleNameLoc,
+                                              diag::err_module_not_built)
+        << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
+  };
+
   // FIXME: have LockFileManager return an error_code so that we can
   // avoid the mkdir when the directory already exists.
   StringRef Dir = llvm::sys::path::parent_path(ModuleFileName);
@@ -1000,9 +1008,11 @@ static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
 
     case llvm::LockFileManager::LFS_Owned:
       // We're responsible for building the module ourselves.
-      // FIXME: if there are errors, don't attempt to load the module.
-      compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
-                        ModuleFileName);
+      if (!compileModuleImpl(ImportingInstance, ModuleNameLoc, Module,
+                             ModuleFileName)) {
+        diagnoseBuildFailure();
+        return false;
+      }
       break;
 
     case llvm::LockFileManager::LFS_Shared:
@@ -1027,9 +1037,7 @@ static bool compileAndLoadModule(CompilerInstance &ImportingInstance,
       // consistent with this ImportingInstance.  Try again...
       continue;
     } else if (ReadResult == ASTReader::Missing) {
-      ImportingInstance.getDiagnostics().Report(ModuleNameLoc,
-                                                diag::err_module_not_built)
-          << Module->Name << SourceRange(ImportLoc, ModuleNameLoc);
+      diagnoseBuildFailure();
     }
     return ReadResult == ASTReader::Success;
   }
-- 
2.7.4