[modules] If we hit a failure while loading a PCH/module, abort parsing instead of trying to continue in an invalid state.

Also don't let libclang create a PCH with such an error.

Fixes rdar://13953768

llvm-svn: 182629

2 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/Frontend/ASTUnit.cpp b/clang/lib/Frontend/ASTUnit.cpp
index 7850dc697be..2d916536d3d 100644
--- a/clang/lib/Frontend/ASTUnit.cpp
+++ b/clang/lib/Frontend/ASTUnit.cpp
@@ -216,7 +216,8 @@ const unsigned DefaultPreambleRebuildInterval = 5;
 static llvm::sys::cas_flag ActiveASTUnitObjects;
 
 ASTUnit::ASTUnit(bool _MainFileIsAST)
-  : Reader(0), OnlyLocalDecls(false), CaptureDiagnostics(false),
+  : Reader(0), HadModuleLoaderFatalFailure(false),
+    OnlyLocalDecls(false), CaptureDiagnostics(false),
     MainFileIsAST(_MainFileIsAST), 
     TUKind(TU_Complete), WantTiming(getenv("LIBCLANG_TIMING")),
     OwnsRemappedFileBuffers(true),
@@ -1705,6 +1706,7 @@ void ASTUnit::transferASTDataFromCompilerInstance(CompilerInstance &CI) {
   CI.setFileManager(0);
   Target = &CI.getTarget();
   Reader = CI.getModuleManager();
+  HadModuleLoaderFatalFailure = CI.hadModuleLoaderFatalFailure();
 }
 
 StringRef ASTUnit::getMainFileName() const {
@@ -2504,6 +2506,9 @@ void ASTUnit::CodeComplete(StringRef File, unsigned Line, unsigned Column,
 }
 
 bool ASTUnit::Save(StringRef File) {
+  if (HadModuleLoaderFatalFailure)
+    return true;
+
   // Write to a temporary file and later rename it to the actual file, to avoid
   // possible race conditions.
   SmallString<128> TempPath;
diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index cf856fc2ab6..b4bb6f32517 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -1247,12 +1247,14 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
     case ASTReader::VersionMismatch:
     case ASTReader::ConfigurationMismatch:
     case ASTReader::HadErrors:
+      ModuleLoader::HadFatalFailure = true;
       // FIXME: The ASTReader will already have complained, but can we showhorn
       // that diagnostic information into a more useful form?
       KnownModules[Path[0].first] = 0;
       return ModuleLoadResult();
 
     case ASTReader::Failure:
+      ModuleLoader::HadFatalFailure = true;
       // Already complained, but note now that we failed.
       KnownModules[Path[0].first] = 0;
       ModuleBuildFailed = true;