Add clang-cl alias to allow users to disable c4005

If we ever want three or more aliases, at that point we should put MSVC
warning ids in DiagnosticGroups.td.  We can use that to support #pragma
warning.

llvm-svn: 205598

2 files changed, 6 insertions, 0 deletions

diff --git a/clang/include/clang/Driver/CLCompatOptions.td b/clang/include/clang/Driver/CLCompatOptions.td
index d33e6b67f0d..2bfc78ed1b8 100644
--- a/clang/include/clang/Driver/CLCompatOptions.td
+++ b/clang/include/clang/Driver/CLCompatOptions.td
@@ -121,6 +121,8 @@ def _SLASH_WX : CLFlag<"WX">, HelpText<"Treat warnings as errors">,
 def _SLASH_WX_ : CLFlag<"WX-">, HelpText<"Do not treat warnings as errors">,
   Alias<W_Joined>, AliasArgs<["no-error"]>;
 def _SLASH_w_flag : CLFlag<"w">, HelpText<"Disable all warnings">, Alias<w>;
+def _SLASH_wd4005 : CLFlag<"wd4005">, Alias<W_Joined>,
+  AliasArgs<["no-macro-redefined"]>;
 def _SLASH_vd : CLJoined<"vd">, HelpText<"Control vtordisp placement">,
   Alias<vtordisp_mode_EQ>;
 def _SLASH_Z7 : CLFlag<"Z7">, Alias<gline_tables_only>;
diff --git a/clang/test/Driver/cl-options.c b/clang/test/Driver/cl-options.c
index a6661311737..84fa2699eef 100644
--- a/clang/test/Driver/cl-options.c
+++ b/clang/test/Driver/cl-options.c
@@ -129,6 +129,10 @@
 // WJoined: "-cc1"
 // WJoined: "-Wunused-pragmas"
 
+// For some warning ids, we can map from MSVC warning to Clang warning.
+// RUN: %clang_cl -wd4005 -### -- %s 2>&1 | FileCheck -check-prefix=wd4005 %s
+// wd4005: "-cc1"
+// wd4005: "-Wno-macro-redefined"
 
 // Ignored options. Check that we don't get "unused during compilation" errors.
 // (/Zs is for syntax-only)