[PowerPC] Option for secure plt mode

This patch enables option for secure plt mode in
clang (-msecure-plt).

Differential Revision: https://reviews.llvm.org/D44921

llvm-svn: 329795
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index e2c503b..ab9335a 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -1957,6 +1957,7 @@
 def mno_altivec : Flag<["-"], "mno-altivec">, Group<m_ppc_Features_Group>;
 def mvsx : Flag<["-"], "mvsx">, Group<m_ppc_Features_Group>;
 def mno_vsx : Flag<["-"], "mno-vsx">, Group<m_ppc_Features_Group>;
+def msecure_plt : Flag<["-"], "msecure-plt">, Group<m_ppc_Features_Group>;
 def mpower8_vector : Flag<["-"], "mpower8-vector">,
     Group<m_ppc_Features_Group>;
 def mno_power8_vector : Flag<["-"], "mno-power8-vector">,
diff --git a/clang/lib/Driver/ToolChains/Arch/PPC.cpp b/clang/lib/Driver/ToolChains/Arch/PPC.cpp
index 7c7e1c7..f6a9596 100644
--- a/clang/lib/Driver/ToolChains/Arch/PPC.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/PPC.cpp
@@ -106,6 +106,16 @@
   ppc::FloatABI FloatABI = ppc::getPPCFloatABI(D, Args);
   if (FloatABI == ppc::FloatABI::Soft)
     Features.push_back("-hard-float");
+
+  ppc::ReadGOTPtrMode ReadGOT = ppc::getPPCReadGOTPtrMode(D, Args);
+  if (ReadGOT == ppc::ReadGOTPtrMode::SecurePlt)
+    Features.push_back("+secure-plt");
+}
+
+ppc::ReadGOTPtrMode ppc::getPPCReadGOTPtrMode(const Driver &D, const ArgList &Args) {
+  if (Args.getLastArg(options::OPT_msecure_plt))
+    return ppc::ReadGOTPtrMode::SecurePlt;
+  return ppc::ReadGOTPtrMode::Bss;
 }
 
 ppc::FloatABI ppc::getPPCFloatABI(const Driver &D, const ArgList &Args) {
diff --git a/clang/lib/Driver/ToolChains/Arch/PPC.h b/clang/lib/Driver/ToolChains/Arch/PPC.h
index 7d7c681..7eb675c 100644
--- a/clang/lib/Driver/ToolChains/Arch/PPC.h
+++ b/clang/lib/Driver/ToolChains/Arch/PPC.h
@@ -29,10 +29,17 @@
   Hard,
 };
 
+enum class ReadGOTPtrMode {
+  Bss,
+  SecurePlt,
+};
+
 FloatABI getPPCFloatABI(const Driver &D, const llvm::opt::ArgList &Args);
 
 std::string getPPCTargetCPU(const llvm::opt::ArgList &Args);
 const char *getPPCAsmModeForCPU(StringRef Name);
+ReadGOTPtrMode getPPCReadGOTPtrMode(const Driver &D,
+	                                const llvm::opt::ArgList &Args);
 
 void getPPCTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                           const llvm::opt::ArgList &Args,
diff --git a/clang/test/Driver/ppc-features.cpp b/clang/test/Driver/ppc-features.cpp
index 621c407..1cb6cee 100644
--- a/clang/test/Driver/ppc-features.cpp
+++ b/clang/test/Driver/ppc-features.cpp
@@ -22,6 +22,10 @@
 // RUN: %clang -target powerpc-unknown-linux-gnu %s -msoft-float -mhard-float -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SOFTHARD %s
 // CHECK-SOFTHARD-NOT: "-target-feature" "-hard-float"
 
+// check -msecure-plt option for ppc32
+// RUN: %clang -target powerpc-unknown-linux-gnu -msecure-plt %s  -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-SECUREPLT %s
+// CHECK-SECUREPLT: "-target-feature" "+secure-plt"
+
 // check -mfloat-abi=x option
 // RUN: %clang -target powerpc-unknown-linux-gnu %s -mfloat-abi=x -### -o %t.o 2>&1 | FileCheck --check-prefix=CHECK-ERRMSG %s
 // CHECK-ERRMSG: error: invalid float ABI '-mfloat-abi=x'