4 files changed, 3 insertions, 17 deletions
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index c8673e50a05..a55a3257851 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -366,7 +366,7 @@ bool GenerateModuleAction::ComputeASTConsumerArguments(CompilerInstance &CI,
     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
     CI.getFrontendOpts().OutputFile =
         HS.getModuleFileName(CI.getLangOpts().CurrentModule,
-                             ModuleMapForUniquing->getName(), IsSystem);
+                             ModuleMapForUniquing->getName());
   }
   
   // We use createOutputFile here because this is exposed via libclang, and we
diff --git a/clang/lib/Lex/HeaderSearch.cpp b/clang/lib/Lex/HeaderSearch.cpp
index f76d851ac6c..d6b255fb014 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -115,13 +115,11 @@ const HeaderMap *HeaderSearch::CreateHeaderMap(const FileEntry *FE) {
 std::string HeaderSearch::getModuleFileName(Module *Module) {
   const FileEntry *ModuleMap =
       getModuleMap().getModuleMapFileForUniquing(Module);
-  return getModuleFileName(Module->Name, ModuleMap->getName(),
-                           Module->IsSystem);
+  return getModuleFileName(Module->Name, ModuleMap->getName());
 }
 
 std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
-                                            StringRef ModuleMapPath,
-                                            bool IsSystem) {
+                                            StringRef ModuleMapPath) {
   // If we don't have a module cache path, we can't do anything.
   if (ModuleCachePath.empty()) 
     return std::string();
@@ -149,10 +147,6 @@ std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
     llvm::hash_code Hash =
         llvm::hash_combine(DirName.lower(), FileName.lower());
 
-    // Hash the IsSystem bit, since changing search paths can change whether a
-    // module is considered 'system' or not.
-    Hash = llvm::hash_combine(Hash, IsSystem);
-
     SmallString<128> HashStr;
     llvm::APInt(64, size_t(Hash)).toStringUnsigned(HashStr, /*Radix*/36);
     llvm::sys::path::append(Result, ModuleName + "-" + HashStr.str() + ".pcm");
diff --git a/clang/lib/Serialization/ASTReader.cpp b/clang/lib/Serialization/ASTReader.cpp
index 7774b7b1c6e..bb6a450222d 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3468,13 +3468,6 @@ ASTReader::ReadModuleMapFileBlock(RecordData &Record, ModuleFile &F,
           << F.ModuleName << /*not new*/1 << ModMap->getName();
       return OutOfDate;
     }
-
-    // Check whether the 'IsSystem' bit changed.
-    if (M->IsSystem != static_cast<bool>(Record[Idx])) {
-      if ((ClientLoadCapabilities & ARR_OutOfDate) == 0)
-        Diag(diag::err_module_system_change) << F.ModuleName << M->IsSystem;
-      return OutOfDate;
-    }
   }
 
   if (Listener)
diff --git a/clang/lib/Serialization/ASTWriter.cpp b/clang/lib/Serialization/ASTWriter.cpp
index c0ce5f8e5ca..07d5d29e44b 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1216,7 +1216,6 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
       Record.push_back(0);
     }
 
-    Record.push_back(WritingModule->IsSystem);
     Stream.EmitRecord(MODULE_MAP_FILE, Record);
   }