[modules] Incrementally compute the list of overridden module macros based on

the active module macros at the point of definition, rather than reconstructing
it from the macro history. No functionality change intended.

llvm-svn: 235941

1 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/Lex/Preprocessor.cpp b/clang/lib/Lex/Preprocessor.cpp
index 6f2e390fc03..92ab2af1921 100644
--- a/clang/lib/Lex/Preprocessor.cpp
+++ b/clang/lib/Lex/Preprocessor.cpp
@@ -73,7 +73,8 @@ Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
       ModuleImportExpectsIdentifier(false), CodeCompletionReached(0),
       MainFileDir(nullptr), SkipMainFilePreamble(0, true), CurPPLexer(nullptr),
       CurDirLookup(nullptr), CurLexerKind(CLK_Lexer), CurSubmodule(nullptr),
-      Callbacks(nullptr), MacroArgCache(nullptr), Record(nullptr),
+      Callbacks(nullptr), MacroVisibilityGeneration(0),
+      MacroArgCache(nullptr), Record(nullptr),
       MIChainHead(nullptr), DeserialMIChainHead(nullptr) {
   OwnsHeaderSearch = OwnsHeaders;
   
@@ -748,11 +749,13 @@ void Preprocessor::LexAfterModuleImport(Token &Result) {
   // If we have a non-empty module path, load the named module.
   if (!ModuleImportPath.empty()) {
     Module *Imported = nullptr;
-    if (getLangOpts().Modules)
+    if (getLangOpts().Modules) {
       Imported = TheModuleLoader.loadModule(ModuleImportLoc,
                                             ModuleImportPath,
                                             Module::MacrosVisible,
                                             /*IsIncludeDirective=*/false);
+      ++MacroVisibilityGeneration;
+    }
     if (Callbacks && (getLangOpts().Modules || getLangOpts().DebuggerSupport))
       Callbacks->moduleImport(ModuleImportLoc, ModuleImportPath, Imported);
   }