[clang][SystemZ] Add support for -march=native

Handle -march=native in systemz::getSystemZTargetCPU, similar to
how this is done on other platforms.  Also change the return type
to std::string instead of const char *.

1 files changed, 15 insertions, 3 deletions

diff --git a/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp b/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
index ca60b85cf8a..2b77d59fdc6 100644
--- a/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/SystemZ.cpp
@@ -9,15 +9,27 @@
 #include "SystemZ.h"
 #include "clang/Driver/Options.h"
 #include "llvm/Option/ArgList.h"
+#include "llvm/Support/Host.h"
 
 using namespace clang::driver;
 using namespace clang::driver::tools;
 using namespace clang;
 using namespace llvm::opt;
 
-const char *systemz::getSystemZTargetCPU(const ArgList &Args) {
-  if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ))
-    return A->getValue();
+std::string systemz::getSystemZTargetCPU(const ArgList &Args) {
+  if (const Arg *A = Args.getLastArg(clang::driver::options::OPT_march_EQ)) {
+    llvm::StringRef CPUName = A->getValue();
+
+    if (CPUName == "native") {
+      std::string CPU = llvm::sys::getHostCPUName();
+      if (!CPU.empty() && CPU != "generic")
+        return CPU;
+      else
+        return "";
+    }
+
+    return CPUName;
+  }
   return "z10";
 }