[Driver][Darwin] Emit an error when using -pg on OS without support for it.

Instead of letting a program fail at runtime, emit an error during
compilation.

rdar://problem/12206955

Reviewers: dexonsmith, bob.wilson, steven_wu

Reviewed By: steven_wu

Subscribers: jkorous, cfe-commits

Differential Revision: https://reviews.llvm.org/D57991

llvm-svn: 354084

1 files changed, 19 insertions, 14 deletions

diff --git a/clang/lib/Driver/ToolChains/Darwin.cpp b/clang/lib/Driver/ToolChains/Darwin.cpp
index 582f3f9c4aa..9b3f3740fd4 100644
--- a/clang/lib/Driver/ToolChains/Darwin.cpp
+++ b/clang/lib/Driver/ToolChains/Darwin.cpp
@@ -2289,22 +2289,27 @@ void Darwin::addStartObjectFileArgs(const ArgList &Args,
       }
     } else {
       if (Args.hasArg(options::OPT_pg) && SupportsProfiling()) {
-        if (Args.hasArg(options::OPT_static) ||
-            Args.hasArg(options::OPT_object) ||
-            Args.hasArg(options::OPT_preload)) {
-          CmdArgs.push_back("-lgcrt0.o");
-        } else {
-          CmdArgs.push_back("-lgcrt1.o");
+        if (isTargetMacOS() && isMacosxVersionLT(10, 9)) {
+          if (Args.hasArg(options::OPT_static) ||
+              Args.hasArg(options::OPT_object) ||
+              Args.hasArg(options::OPT_preload)) {
+            CmdArgs.push_back("-lgcrt0.o");
+          } else {
+            CmdArgs.push_back("-lgcrt1.o");
 
-          // darwin_crt2 spec is empty.
+            // darwin_crt2 spec is empty.
+          }
+          // By default on OS X 10.8 and later, we don't link with a crt1.o
+          // file and the linker knows to use _main as the entry point.  But,
+          // when compiling with -pg, we need to link with the gcrt1.o file,
+          // so pass the -no_new_main option to tell the linker to use the
+          // "start" symbol as the entry point.
+          if (isTargetMacOS() && !isMacosxVersionLT(10, 8))
+            CmdArgs.push_back("-no_new_main");
+        } else {
+          getDriver().Diag(diag::err_drv_clang_unsupported_opt_pg_darwin)
+              << isTargetMacOS();
         }
-        // By default on OS X 10.8 and later, we don't link with a crt1.o
-        // file and the linker knows to use _main as the entry point.  But,
-        // when compiling with -pg, we need to link with the gcrt1.o file,
-        // so pass the -no_new_main option to tell the linker to use the
-        // "start" symbol as the entry point.
-        if (isTargetMacOS() && !isMacosxVersionLT(10, 8))
-          CmdArgs.push_back("-no_new_main");
       } else {
         if (Args.hasArg(options::OPT_static) ||
             Args.hasArg(options::OPT_object) ||