[ARM][CMSE] Add commandline option and feature macro

Defines macro ARM_FEATURE_CMSE to 1 for v8-M targets and introduces
-mcmse option which for v8-M targets sets ARM_FEATURE_CMSE to 3.
A diagnostic is produced when the option is given on architectures
without support for Security Extensions.
Reviewed By: dmgreen, snidertm
Differential Revision: https://reviews.llvm.org/D59879

llvm-svn: 361261

4 files changed, 17 insertions, 0 deletions

diff --git a/clang/lib/Basic/Targets/ARM.cpp b/clang/lib/Basic/Targets/ARM.cpp
index b74514ea2c8..55c0d371598 100644
--- a/clang/lib/Basic/Targets/ARM.cpp
+++ b/clang/lib/Basic/Targets/ARM.cpp
@@ -434,6 +434,11 @@ bool ARMTargetInfo::handleTargetFeatures(std::vector<std::string> &Features,
       DSP = 1;
     } else if (Feature == "+fp-only-sp") {
       HW_FP_remove |= HW_FP_DP;
+    } else if (Feature == "+8msecext") {
+      if (CPUProfile != "M" || ArchVersion != 8) {
+        Diags.Report(diag::err_target_unsupported_mcmse) << CPU;
+        return false;
+      }
     } else if (Feature == "+strict-align") {
       Unaligned = 0;
     } else if (Feature == "+fp16") {
@@ -713,6 +718,10 @@ void ARMTargetInfo::getTargetDefines(const LangOptions &Opts,
 
   Builder.defineMacro("__ARM_SIZEOF_MINIMAL_ENUM", Opts.ShortEnums ? "1" : "4");
 
+  // CMSE
+  if (ArchVersion == 8 && ArchProfile == llvm::ARM::ProfileKind::M)
+    Builder.defineMacro("__ARM_FEATURE_CMSE", Opts.Cmse ? "3" : "1");
+
   if (ArchVersion >= 6 && CPUAttr != "6M" && CPUAttr != "8M_BASE") {
     Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_1");
     Builder.defineMacro("__GCC_HAVE_SYNC_COMPARE_AND_SWAP_2");
diff --git a/clang/lib/Driver/ToolChains/Arch/ARM.cpp b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
index 9e0c4835716..77fad7ed68f 100644
--- a/clang/lib/Driver/ToolChains/Arch/ARM.cpp
+++ b/clang/lib/Driver/ToolChains/Arch/ARM.cpp
@@ -469,6 +469,10 @@ fp16_fml_fallthrough:
     }
   }
 
+  // CMSE: Check for target 8M (for -mcmse to be applicable) is performed later.
+  if (Args.getLastArg(options::OPT_mcmse))
+    Features.push_back("+8msecext");
+
   // Look for the last occurrence of -mlong-calls or -mno-long-calls. If
   // neither options are specified, see if we are compiling for kernel/kext and
   // decide whether to pass "+long-calls" based on the OS and its version.
diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
index 5f8daa2b4a7..556fe873f8f 100644
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -1423,6 +1423,9 @@ void Clang::AddARMTargetArgs(const llvm::Triple &Triple, const ArgList &Args,
   if (!Args.hasFlag(options::OPT_mimplicit_float,
                     options::OPT_mno_implicit_float, true))
     CmdArgs.push_back("-no-implicit-float");
+
+  if (Args.getLastArg(options::OPT_mcmse))
+    CmdArgs.push_back("-mcmse");
 }
 
 void Clang::RenderTargetOptions(const llvm::Triple &EffectiveTriple,
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 8a2dbcddfa9..7cdc050e467 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2729,6 +2729,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   Opts.HalfArgsAndReturns = Args.hasArg(OPT_fallow_half_arguments_and_returns)
                             | Opts.NativeHalfArgsAndReturns;
   Opts.GNUAsm = !Args.hasArg(OPT_fno_gnu_inline_asm);
+  Opts.Cmse = Args.hasArg(OPT_mcmse); // Armv8-M Security Extensions
 
   // __declspec is enabled by default for the PS4 by the driver, and also
   // enabled for Microsoft Extensions or Borland Extensions, here.