Modules: Make missing headers in a module.map a warning not an error.

Instead, mark the module as unavailable so that clang errors as soon as
someone tries to build this module.

A better long-term strategy might be to not stat the header files at all
while reading the module map and instead read them only when the module
is being built (there is a corresponding FIXME in parseHeaderDecl()).
However, it seems non-trivial to get there and this would be a temporary
solution to unblock us.

Also changed the implementation to reuse the same DiagnosticsEngine as
otherwise warnings can't be enabled or disabled with command-line flags.

llvm-svn: 197388

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/test/Modules/modular_maps.cpp b/clang/test/Modules/modular_maps.cpp
index 9c9aba85a91..cb305f2dfdb 100644
--- a/clang/test/Modules/modular_maps.cpp
+++ b/clang/test/Modules/modular_maps.cpp
@@ -1,5 +1,7 @@
 // RUN: rm -rf %t
-// RUN: %clang_cc1 -x objective-c++ -fmodules-cache-path=%t -fmodules -fmodule-map-file=%S/Inputs/modular_maps/modulea.map -I %S/Inputs/modular_maps %s -verify
+// RUN: %clang_cc1 -fmodules -fmodule-maps -fmodules-cache-path=%t -fmodule-map-file=%S/Inputs/modular_maps/modulea.map -I %S/Inputs/modular_maps %s -verify
+
+// expected-warning@Inputs/modular_maps/modulea.map:4{{header 'doesnotexists.h' not found}}
 
 #include "common.h"
 #include "a.h"