Define __FINITE_MATH_ONLY__ based on -ffast-math and -ffinite-math-only.

This macro was being unconditionally set to zero, preceded by a FIXME comment.
This fixes <rdar://problem/11845441>.  Patch by Michael Gottesman!

llvm-svn: 160491

1 files changed, 7 insertions, 4 deletions

diff --git a/clang/lib/Driver/Tools.cpp b/clang/lib/Driver/Tools.cpp
index 59196b20e28..e07068aea14 100644
--- a/clang/lib/Driver/Tools.cpp
+++ b/clang/lib/Driver/Tools.cpp
@@ -1823,12 +1823,15 @@ void Clang::ConstructJob(Compilation &C, const JobAction &JA,
     }
   }
 
-  // We separately look for the '-ffast-math' flag, and if we find it, tell the
-  // frontend to provide the appropriate preprocessor macros. This is distinct
-  // from enabling any optimizations as it induces a language change which must
-  // survive serialization and deserialization, etc.
+  // We separately look for the '-ffast-math' and '-ffinite-math-only' flags,
+  // and if we find them, tell the frontend to provide the appropriate
+  // preprocessor macros. This is distinct from enabling any optimizations as
+  // these options induce language changes which must survive serialization
+  // and deserialization, etc.
   if (Args.hasArg(options::OPT_ffast_math))
     CmdArgs.push_back("-ffast-math");
+  if (Args.hasArg(options::OPT_ffinite_math_only))
+    CmdArgs.push_back("-ffinite-math-only");
 
   // Decide whether to use verbose asm. Verbose assembly is the default on
   // toolchains which have the integrated assembler on by default.