[modules] If a module #includes a modular header that #undef's its macro, it

should not export the macro.

... at least, not unless we have local submodule visibility enabled.

llvm-svn: 236369

1 files changed, 4 insertions, 5 deletions

diff --git a/clang/lib/Lex/PPLexerChange.cpp b/clang/lib/Lex/PPLexerChange.cpp
index c506aa7f6f0..d4defdd71a7 100644
--- a/clang/lib/Lex/PPLexerChange.cpp
+++ b/clang/lib/Lex/PPLexerChange.cpp
@@ -620,8 +620,7 @@ void Preprocessor::EnterSubmodule(Module *M, SourceLocation ImportLoc) {
 
   // Determine the set of starting macros for this submodule.
   // FIXME: If we re-enter a submodule, should we restore its MacroDirectives?
-  auto &StartingMacros = (getLangOpts().ModulesLocalVisibility &&
-                          BuildingSubmoduleStack.size() > 1)
+  auto &StartingMacros = getLangOpts().ModulesLocalVisibility
                              ? BuildingSubmoduleStack[0].Macros
                              : Info.Macros;
 
@@ -661,13 +660,13 @@ void Preprocessor::LeaveSubmodule() {
          MD = MD->getPrevious()) {
       assert(MD && "broken macro directive chain");
 
-      // Skip macros defined in other submodules we #included along the way.
+      // Stop on macros defined in other submodules we #included along the way.
       // There's no point doing this if we're tracking local submodule
-      // visibiltiy, since there can be no such directives in our list.
+      // visibility, since there can be no such directives in our list.
       if (!getLangOpts().ModulesLocalVisibility) {
         Module *Mod = getModuleContainingLocation(MD->getLocation());
         if (Mod != Info.M)
-          continue;
+          break;
       }
 
       if (auto *VisMD = dyn_cast<VisibilityMacroDirective>(MD)) {