Clang support for -flto=thin.

Summary:
Add clang support for -flto=thin option, which is used to set the
EmitFunctionSummary code gen option on compiles.

Add -flto=full as an alias to the existing -flto.

Add tests to check for proper overriding of -flto variants on the
command line, and convert grep tests to FileCheck.

Reviewers: dexonsmith, joker.eph

Subscribers: davidxl, cfe-commits

Differential Revision: http://reviews.llvm.org/D11908

llvm-svn: 250398

1 files changed, 3 insertions, 1 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 4220487e4d8..61144fc558b 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -499,7 +499,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
 
   Opts.MergeFunctions = Args.hasArg(OPT_fmerge_functions);
 
-  Opts.PrepareForLTO = Args.hasArg(OPT_flto);
+  Opts.PrepareForLTO = Args.hasArg(OPT_flto, OPT_flto_EQ);
+  const Arg *A = Args.getLastArg(OPT_flto, OPT_flto_EQ);
+  Opts.EmitFunctionSummary = A && A->containsValue("thin");
 
   Opts.MSVolatile = Args.hasArg(OPT_fms_volatile);