Allow searching for prebuilt implicit modules.

This reverts commit c67656b994c87224e0b33e2c4b09093986a5cfa6, and addresses the
build issue.

1 files changed, 11 insertions, 7 deletions

diff --git a/clang/lib/Frontend/CompilerInstance.cpp b/clang/lib/Frontend/CompilerInstance.cpp
index 030ef42..f4b00df 100644
--- a/clang/lib/Frontend/CompilerInstance.cpp
+++ b/clang/lib/Frontend/CompilerInstance.cpp
@@ -428,8 +428,12 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
 
   PP->setPreprocessedOutput(getPreprocessorOutputOpts().ShowCPP);
 
-  if (PP->getLangOpts().Modules && PP->getLangOpts().ImplicitModules)
-    PP->getHeaderSearchInfo().setModuleCachePath(getSpecificModuleCachePath());
+  if (PP->getLangOpts().Modules && PP->getLangOpts().ImplicitModules) {
+    std::string ModuleHash = getInvocation().getModuleHash();
+    PP->getHeaderSearchInfo().setModuleHash(ModuleHash);
+    PP->getHeaderSearchInfo().setModuleCachePath(
+        getSpecificModuleCachePath(ModuleHash));
+  }
 
   // Handle generating dependencies, if requested.
   const DependencyOutputOptions &DepOpts = getDependencyOutputOpts();
@@ -477,13 +481,11 @@ void CompilerInstance::createPreprocessor(TranslationUnitKind TUKind) {
   }
 }
 
-std::string CompilerInstance::getSpecificModuleCachePath() {
-  // Set up the module path, including the hash for the
-  // module-creation options.
+std::string CompilerInstance::getSpecificModuleCachePath(StringRef ModuleHash) {
+  // Set up the module path, including the hash for the module-creation options.
   SmallString<256> SpecificModuleCache(getHeaderSearchOpts().ModuleCachePath);
   if (!SpecificModuleCache.empty() && !getHeaderSearchOpts().DisableModuleHash)
-    llvm::sys::path::append(SpecificModuleCache,
-                            getInvocation().getModuleHash());
+    llvm::sys::path::append(SpecificModuleCache, ModuleHash);
   return std::string(SpecificModuleCache.str());
 }
 
@@ -1673,6 +1675,8 @@ static ModuleSource selectModuleSource(
   if (!HSOpts.PrebuiltModuleFiles.empty() ||
       !HSOpts.PrebuiltModulePaths.empty()) {
     ModuleFilename = HS.getPrebuiltModuleFileName(ModuleName);
+    if (HSOpts.EnablePrebuiltImplicitModules && ModuleFilename.empty())
+      ModuleFilename = HS.getPrebuiltImplicitModuleFileName(M);
     if (!ModuleFilename.empty())
       return MS_PrebuiltModulePath;
   }