When building a module, all headers of submodules can be used.

This extends r232159.

llvm-svn: 232168

2 files changed, 11 insertions, 1 deletions

diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
index 6aefb035266..b0195af70b6 100644
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -265,7 +265,8 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
   if (Known != Headers.end()) {
     for (const KnownHeader &Header : Known->second) {
       // If 'File' is part of 'RequestingModule' we can definitely include it.
-      if (Header.getModule() == RequestingModule)
+      if (Header.getModule() &&
+          Header.getModule()->isSubModuleOf(RequestingModule))
         return;
 
       // Remember private headers for later printing of a diagnostic.
diff --git a/clang/test/Modules/declare-use5.cpp b/clang/test/Modules/declare-use5.cpp
new file mode 100644
index 00000000000..b34be0f1104
--- /dev/null
+++ b/clang/test/Modules/declare-use5.cpp
@@ -0,0 +1,9 @@
+// RUN: rm -rf %t
+// RUN: %clang_cc1 -fmodule-maps -fmodules-cache-path=%t -fmodules-decluse -fmodule-name=XN -I %S/Inputs/declare-use %s -verify
+
+
+#include "sub.h"
+
+const int a = sub;
+
+// expected-no-diagnostics