[PCH/Modules] Check that the specific module cache path the PCH was built with, is the same as

the one in the current compiler invocation. If they differ reject the PCH.

This protects against the badness occurring from getting modules loaded from different module caches (see crashes).

rdar://19889860

llvm-svn: 229909

1 files changed, 12 insertions, 8 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 187e2b78b8f..5d554b717b3 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -329,14 +329,7 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
 
   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
 
-  // Set up the module path, including the hash for the
-  // module-creation options.
-  SmallString<256> SpecificModuleCache(
-                           getHeaderSearchOpts().ModuleCachePath);
-  if (!getHeaderSearchOpts().DisableModuleHash)
-    llvm::sys::path::append(SpecificModuleCache,
-                            getInvocation().getModuleHash());
-  PP->getHeaderSearchInfo().setModuleCachePath(SpecificModuleCache);
+  PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
 
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
@@ -373,6 +366,17 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
   }
 }
 
+std::string CompilerInstance::getSpecificModuleCachePath() {
+  // Set up the module path, including the hash for the
+  // module-creation options.
+  SmallString<256> SpecificModuleCache(
+                           getHeaderSearchOpts().ModuleCachePath);
+  if (!getHeaderSearchOpts().DisableModuleHash)
+    llvm::sys::path::append(SpecificModuleCache,
+                            getInvocation().getModuleHash());
+  return SpecificModuleCache.str();
+}
+
 // ASTContext
 
 void CompilerInstance::createASTContext() {