[coroutines] Support "coroutines" feature in module map requires clause

Summary: In order for libc++ to add `<experimental/coroutine>` to its module map, there has to be a feature that can be used to detect if coroutines support is enabled in Clang. 

Reviewers: rsmith

Reviewed By: rsmith

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33538

llvm-svn: 304054

3 files changed, 14 insertions, 1 deletions

diff --git a/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/coroutines.h b/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/coroutines.h
new file mode 100644
index 00000000000..85281f5a099
--- /dev/null
+++ b/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/coroutines.h
@@ -0,0 +1,3 @@
+#ifndef __cpp_coroutines
+#error coroutines must be enabled
+#endif
diff --git a/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/not_coroutines.h b/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/not_coroutines.h
new file mode 100644
index 00000000000..9312b9ad892
--- /dev/null
+++ b/clang/test/Modules/Inputs/DependsOnModule.framework/Headers/not_coroutines.h
@@ -0,0 +1,3 @@
+#ifdef __cpp_coroutines
+#error coroutines must NOT be enabled
+#endif
diff --git a/clang/test/Modules/Inputs/DependsOnModule.framework/module.map b/clang/test/Modules/Inputs/DependsOnModule.framework/module.map
index b62308583df..4d468f2a8c0 100644
--- a/clang/test/Modules/Inputs/DependsOnModule.framework/module.map
+++ b/clang/test/Modules/Inputs/DependsOnModule.framework/module.map
@@ -22,7 +22,14 @@ framework module DependsOnModule {
   explicit module CustomReq2 {
     requires custom_req2
   }
-
+  explicit module Coroutines {
+    requires coroutines
+    header "coroutines.h"
+  }
+  explicit module NotCoroutines {
+    requires !coroutines
+    header "not_coroutines.h"
+  }
   explicit framework module SubFramework {
     umbrella header "SubFramework.h"