[ARM] Clean up ARM target & feature checking in clang driver.

[hliao]

Summary

• Similar to other targets, instead of passing a toolchain, a driver argument should be passed into arm::getARMTargetFeatures. Also, that routine should honor the specified triple. Refactor arm::getARMFloatABI with separate interfaces. One has the original parameters and the other uses the driver and the specified triple.
• That fixes an issue when target & features are queried during the offload compilation, where the specified triple should be checked instead of that effective triple. Previous failed test is re-enabled.

[hliao]

revise the commit message.

[merge_guards_bot]

Unit tests: unknown.

clang-tidy: pass.

clang-format: fail. Please format your changes with clang-format by running git-clang-format HEAD^ or applying this patch.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[hliao]

revise formatting

[merge_guards_bot]

Unit tests: unknown.

clang-tidy: pass.

clang-format: pass.

Build artifacts: diff.json, clang-tidy.txt, clang-format.patch, CMakeCache.txt, console-log.txt

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

[merge_guards_bot]

Unit tests: unknown.

clang-tidy: unknown.

clang-format: unknown.

Build artifacts: console-log.txt

Pre-merge checks is in beta. Report issue. Please join beta or enable it for your project.

clang/lib/Driver/ToolChains/Arch/ARM.h

 enum class FloatABI {
   Invalid,
   Soft,
   SoftFP,
   Hard,
 };
 
 FloatABI getARMFloatABI(const ToolChain &TC, const llvm::opt::ArgList &Args);
-ReadTPMode getReadTPMode(const ToolChain &TC, const llvm::opt::ArgList &Args);
+FloatABI getARMFloatABI(const Driver &D, const llvm::Triple &Triple,
+                        const llvm::opt::ArgList &Args);
+ReadTPMode getReadTPMode(const Driver &D, const llvm::opt::ArgList &Args);
 
 bool useAAPCSForMachO(const llvm::Triple &T);
 void getARMArchCPUFromArgs(const llvm::opt::ArgList &Args,
                            llvm::StringRef &Arch, llvm::StringRef &CPU,
                            bool FromAs = false);
-void getARMTargetFeatures(const ToolChain &TC, const llvm::Triple &Triple,
+void getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
                           const llvm::opt::ArgList &Args,
                           llvm::opt::ArgStringList &CmdArgs,
                           std::vector<llvm::StringRef> &Features, bool ForAS);
 int getARMSubArchVersionNumber(const llvm::Triple &Triple);
 bool isARMMProfile(const llvm::Triple &Triple);
 
 } // end namespace arm
 } // end namespace tools
 } // end namespace driver
 } // end namespace clang
 
 #endif // LLVM_CLANG_LIB_DRIVER_TOOLCHAINS_ARCH_ARM_H

clang/lib/Driver/ToolChains/Arch/ARM.cpp

 bool arm::useAAPCSForMachO(const llvm::Triple &T) {
   // The backend is hardwired to assume AAPCS for M-class processors, ensure
   // the frontend matches that.
   return T.getEnvironment() == llvm::Triple::EABI ||
          T.getOS() == llvm::Triple::UnknownOS || isARMMProfile(T);
 }
 
 // Select mode for reading thread pointer (-mtp=soft/cp15).
-arm::ReadTPMode arm::getReadTPMode(const ToolChain &TC, const ArgList &Args) {
+arm::ReadTPMode arm::getReadTPMode(const Driver &D, const ArgList &Args) {
   if (Arg *A = Args.getLastArg(options::OPT_mtp_mode_EQ)) {
-    const Driver &D = TC.getDriver();
     arm::ReadTPMode ThreadPointer =
         llvm::StringSwitch<arm::ReadTPMode>(A->getValue())
             .Case("cp15", ReadTPMode::Cp15)
             .Case("soft", ReadTPMode::Soft)
             .Default(ReadTPMode::Invalid);
     if (ThreadPointer != ReadTPMode::Invalid)
       return ThreadPointer;
     if (StringRef(A->getValue()).empty())
       D.Diag(diag::err_drv_missing_arg_mtp) << A->getAsString(Args);
     else
       D.Diag(diag::err_drv_invalid_mtp) << A->getAsString(Args);
     return ReadTPMode::Invalid;
   }
   return ReadTPMode::Soft;
 }
 
+arm::FloatABI arm::getARMFloatABI(const ToolChain &TC, const ArgList &Args) {
+  return arm::getARMFloatABI(TC.getDriver(), TC.getEffectiveTriple(), Args);
+}
+
 // Select the float ABI as determined by -msoft-float, -mhard-float, and
 // -mfloat-abi=.
-arm::FloatABI arm::getARMFloatABI(const ToolChain &TC, const ArgList &Args) {
-  const Driver &D = TC.getDriver();
-  const llvm::Triple &Triple = TC.getEffectiveTriple();
+arm::FloatABI arm::getARMFloatABI(const Driver &D, const llvm::Triple &Triple,
+                                  const ArgList &Args) {
   auto SubArch = getARMSubArchVersionNumber(Triple);
   arm::FloatABI ABI = FloatABI::Invalid;
   if (Arg *A =
           Args.getLastArg(options::OPT_msoft_float, options::OPT_mhard_float,
                           options::OPT_mfloat_abi_EQ)) {
     if (A->getOption().matches(options::OPT_msoft_float)) {
       ABI = FloatABI::Soft;
     } else if (A->getOption().matches(options::OPT_mhard_float)) {
default:
       }
     }
   }
 
   assert(ABI != FloatABI::Invalid && "must select an ABI");
   return ABI;
 }
 
-void arm::getARMTargetFeatures(const ToolChain &TC,
-                               const llvm::Triple &Triple,
-                               const ArgList &Args,
-                               ArgStringList &CmdArgs,
-                               std::vector<StringRef> &Features,
-                               bool ForAS) {
-  const Driver &D = TC.getDriver();
-
+void arm::getARMTargetFeatures(const Driver &D, const llvm::Triple &Triple,
+                               const ArgList &Args, ArgStringList &CmdArgs,
+                               std::vector<StringRef> &Features, bool ForAS) {
   bool KernelOrKext =
       Args.hasArg(options::OPT_mkernel, options::OPT_fapple_kext);
-  arm::FloatABI ABI = arm::getARMFloatABI(TC, Args);
-  arm::ReadTPMode ThreadPointer = arm::getReadTPMode(TC, Args);
+  arm::FloatABI ABI = arm::getARMFloatABI(D, Triple, Args);
+  arm::ReadTPMode ThreadPointer = arm::getReadTPMode(D, Args);
   const Arg *WaCPU = nullptr, *WaFPU = nullptr;
   const Arg *WaHDiv = nullptr, *WaArch = nullptr;
 
   // This vector will accumulate features from the architecture
   // extension suffixes on -mcpu and -march (e.g. the 'bar' in
   // -mcpu=foo+bar). We want to apply those after the features derived
   // from the FPU, in case -mfpu generates a negative feature which
   // the +bar is supposed to override.

clang/lib/Driver/ToolChains/Clang.cpp

static void getTargetFeatures(const ToolChain &TC, const llvm::Triple &Triple,
   case llvm::Triple::mips64el:
     mips::getMIPSTargetFeatures(D, Triple, Args, Features);
     break;
 
   case llvm::Triple::arm:
   case llvm::Triple::armeb:
   case llvm::Triple::thumb:
   case llvm::Triple::thumbeb:
-    arm::getARMTargetFeatures(TC, Triple, Args, CmdArgs, Features, ForAS);
+    arm::getARMTargetFeatures(D, Triple, Args, CmdArgs, Features, ForAS);
     break;
 
   case llvm::Triple::ppc:
   case llvm::Triple::ppc64:
   case llvm::Triple::ppc64le:
     ppc::getPPCTargetFeatures(D, Triple, Args, Features);
     break;
   case llvm::Triple::riscv32:

clang/test/Driver/cuda-simple.cu

 // Verify that we can parse a simple CUDA file with or without -save-temps
 // http://llvm.org/PR22936
 // RUN: %clang -nocudainc -nocudalib -Werror -fsyntax-only -c %s
-// XFAIL: arm
 //
 // Verify that we pass -x cuda-cpp-output to compiler after
 // preprocessing a CUDA file
 // RUN: %clang  -Werror -### -save-temps -c %s 2>&1 | FileCheck %s
 // CHECK-LABEL: "-cc1"
 // CHECK: "-E"
 // CHECK: "-x" "cuda"
 // CHECK-LABEL: "-cc1"