When we leave a module header, make that header visible in its

includer's context, even if its overall module is unavailable.

llvm-svn: 342096

6 files changed, 37 insertions, 6 deletions

diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index 1a0c1905905..9ff976c03b9 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -577,10 +577,6 @@ void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
   };
 
   std::function<void(Visiting)> VisitModule = [&](Visiting V) {
-    // Modules that aren't available cannot be made visible.
-    if (!V.M->isAvailable())
-      return;
-
     // Nothing to do for a module that's already visible.
     unsigned ID = V.M->getVisibilityID();
     if (ImportLocs.size() <= ID)
@@ -594,8 +590,11 @@ void VisibleModuleSet::setVisible(Module *M, SourceLocation Loc,
     // Make any exported modules visible.
     SmallVector<Module *, 16> Exports;
     V.M->getExportedModules(Exports);
-    for (Module *E : Exports)
-      VisitModule({E, &V});
+    for (Module *E : Exports) {
+      // Don't recurse to unavailable submodules.
+      if (E->isAvailable())
+        VisitModule({E, &V});
+    }
 
     for (auto &C : V.M->Conflicts) {
       if (isVisible(C.Other)) {
diff --git a/clang/test/Modules/Inputs/unavailable-local-visibility/a.h b/clang/test/Modules/Inputs/unavailable-local-visibility/a.h
new file mode 100644
index 00000000000..865bb65f4d2
--- /dev/null
+++ b/clang/test/Modules/Inputs/unavailable-local-visibility/a.h
@@ -0,0 +1,4 @@
+#ifndef A_H
+#define A_H
+#include "x.h"
+#endif
diff --git a/clang/test/Modules/Inputs/unavailable-local-visibility/b.h b/clang/test/Modules/Inputs/unavailable-local-visibility/b.h
new file mode 100644
index 00000000000..71360e38b7b
--- /dev/null
+++ b/clang/test/Modules/Inputs/unavailable-local-visibility/b.h
@@ -0,0 +1,13 @@
+#ifndef B_H
+#define B_H
+#include "a.h"
+
+#ifndef A_H
+#error where is a?
+#endif
+
+#ifndef X_H
+#error where is x?
+#endif
+X f();
+#endif
diff --git a/clang/test/Modules/Inputs/unavailable-local-visibility/module.modulemap b/clang/test/Modules/Inputs/unavailable-local-visibility/module.modulemap
new file mode 100644
index 00000000000..8da3d3c1ab0
--- /dev/null
+++ b/clang/test/Modules/Inputs/unavailable-local-visibility/module.modulemap
@@ -0,0 +1,9 @@
+module M {
+  module a { header "a.h" export * }
+  module b { header "b.h" export * }
+  module doesnotexist { header "doesnotexist.h" }
+}
+module X {
+  header "x.h"
+  export *
+}
diff --git a/clang/test/Modules/Inputs/unavailable-local-visibility/x.h b/clang/test/Modules/Inputs/unavailable-local-visibility/x.h
new file mode 100644
index 00000000000..0498c5d2aab
--- /dev/null
+++ b/clang/test/Modules/Inputs/unavailable-local-visibility/x.h
@@ -0,0 +1,4 @@
+#ifndef X_H
+#define X_H
+struct X {};
+#endif
diff --git a/clang/test/Modules/unavailable-local-visibility.test b/clang/test/Modules/unavailable-local-visibility.test
new file mode 100644
index 00000000000..10b316a50ec
--- /dev/null
+++ b/clang/test/Modules/unavailable-local-visibility.test
@@ -0,0 +1,2 @@
+// RUN: %clang_cc1 -fmodules -I%S/Inputs/unavailable-local-visibility -fmodule-name=X -emit-module -x c++-module-map %S/Inputs/unavailable-local-visibility/module.modulemap -o %t/x.pcm
+// RUN: %clang_cc1 -fmodules -I%S/Inputs/unavailable-local-visibility -fmodule-name=M -fmodule-map-file=%S/Inputs/unavailable-local-visibility/module.modulemap -fmodules-local-submodule-visibility -fmodule-file=%t/x.pcm -fsyntax-only -x c++-header %S/Inputs/unavailable-local-visibility/b.h