Don't build modules with (submodules with) missing headers

Unless they are in submodules that aren't available anyway, due to
requirements not being met.  Also, mark children as unavailable when the
parent is.

llvm-svn: 206664

1 files changed, 5 insertions, 0 deletions

diff --git a/clang/lib/Basic/Module.cpp b/clang/lib/Basic/Module.cpp
index d5c02d84058..6f29fae03a5 100644
--- a/clang/lib/Basic/Module.cpp
+++ b/clang/lib/Basic/Module.cpp
@@ -160,6 +160,11 @@ void Module::addRequirement(StringRef Feature, bool RequiredState,
   if (hasFeature(Feature, LangOpts, Target) == RequiredState)
     return;
 
+  IsMissingRequirement = true;
+  markUnavailable();
+}
+
+void Module::markUnavailable() {
   if (!IsAvailable)
     return;