Mangle the IsSystem bit into the .pcm file name

When mangling the module map path into a .pcm file name, also mangle the
IsSystem bit, which can also depend on the header search paths. For
example, the user may change from -I to -isystem.  This can affect
diagnostics in the importing TU.

llvm-svn: 228966

4 files changed, 17 insertions, 3 deletions

diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 701ef026d49..e7ecb2952ac 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());
+                             ModuleMapForUniquing->getName(), IsSystem);
   }
   
   // 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 d6b255fb014..f76d851ac6c 100644
--- a/clang/lib/Lex/HeaderSearch.cpp
+++ b/clang/lib/Lex/HeaderSearch.cpp
@@ -115,11 +115,13 @@ 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());
+  return getModuleFileName(Module->Name, ModuleMap->getName(),
+                           Module->IsSystem);
 }
 
 std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
-                                            StringRef ModuleMapPath) {
+                                            StringRef ModuleMapPath,
+                                            bool IsSystem) {
   // If we don't have a module cache path, we can't do anything.
   if (ModuleCachePath.empty()) 
     return std::string();
@@ -147,6 +149,10 @@ 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 aa1cdc080ee..fe5c71fafc8 100644
--- a/clang/lib/Serialization/ASTReader.cpp
+++ b/clang/lib/Serialization/ASTReader.cpp
@@ -3435,6 +3435,13 @@ 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 aad4305d8c5..2526c638d30 100644
--- a/clang/lib/Serialization/ASTWriter.cpp
+++ b/clang/lib/Serialization/ASTWriter.cpp
@@ -1215,6 +1215,7 @@ void ASTWriter::WriteControlBlock(Preprocessor &PP, ASTContext &Context,
       Record.push_back(0);
     }
 
+    Record.push_back(WritingModule->IsSystem);
     Stream.EmitRecord(MODULE_MAP_FILE, Record);
   }