Convert cascading if-else-if to switch. NFC

[scott-0]

Summary

Cleanup gnutools::Assemble::ConstructJob as requested in http://reviews.llvm.org/D8196 which I will now rebase to be after this.

[scott-0]

Title should say "Convert cascading if-else-if to switch. NFC"

[rengolin]

LGTM. Thanks!

cfe/trunk/lib/Driver/Tools.cpp

void gnutools::Assemble::ConstructJob(Compilation &C, const JobAction &JA,
                                       const InputInfoList &Inputs,
                                       const ArgList &Args,
                                       const char *LinkingOutput) const {
   claimNoWarnArgs(Args);
 
   ArgStringList CmdArgs;
   bool NeedsKPIC = false;
 
+  switch (getToolChain().getArch()) {
+  default:
+    break;
   // Add --32/--64 to make sure we get the format we want.
   // This is incomplete
-  if (getToolChain().getArch() == llvm::Triple::x86) {
+  case llvm::Triple::x86:
     CmdArgs.push_back("--32");
-  } else if (getToolChain().getArch() == llvm::Triple::x86_64) {
+    break;
+  case llvm::Triple::x86_64:
     if (getToolChain().getTriple().getEnvironment() == llvm::Triple::GNUX32)
       CmdArgs.push_back("--x32");
     else
       CmdArgs.push_back("--64");
-  } else if (getToolChain().getArch() == llvm::Triple::ppc) {
+    break;
+  case llvm::Triple::ppc:
     CmdArgs.push_back("-a32");
     CmdArgs.push_back("-mppc");
     CmdArgs.push_back("-many");
-  } else if (getToolChain().getArch() == llvm::Triple::ppc64) {
+    break;
+  case llvm::Triple::ppc64:
     CmdArgs.push_back("-a64");
     CmdArgs.push_back("-mppc64");
     CmdArgs.push_back("-many");
-  } else if (getToolChain().getArch() == llvm::Triple::ppc64le) {
+    break;
+  case llvm::Triple::ppc64le:
     CmdArgs.push_back("-a64");
     CmdArgs.push_back("-mppc64");
     CmdArgs.push_back("-many");
     CmdArgs.push_back("-mlittle-endian");
-  } else if (getToolChain().getArch() == llvm::Triple::sparc) {
+    break;
+  case llvm::Triple::sparc:
     CmdArgs.push_back("-32");
     CmdArgs.push_back("-Av8plusa");
     NeedsKPIC = true;
-  } else if (getToolChain().getArch() == llvm::Triple::sparcv9) {
+    break;
+  case llvm::Triple::sparcv9:
     CmdArgs.push_back("-64");
     CmdArgs.push_back("-Av9a");
     NeedsKPIC = true;
-  } else if (getToolChain().getArch() == llvm::Triple::arm ||
-             getToolChain().getArch() == llvm::Triple::armeb) {
+    break;
+  case llvm::Triple::arm:
+  case llvm::Triple::armeb:
+  case llvm::Triple::thumb:
+  case llvm::Triple::thumbeb: {
     StringRef MArch = getToolChain().getArchName();
     if (MArch == "armv7" || MArch == "armv7a" || MArch == "armv7-a")
       CmdArgs.push_back("-mfpu=neon");
     if (MArch == "armv8" || MArch == "armv8a" || MArch == "armv8-a" ||
         MArch == "armebv8" || MArch == "armebv8a" || MArch == "armebv8-a")
       CmdArgs.push_back("-mfpu=crypto-neon-fp-armv8");
 
     StringRef ARMFloatABI = tools::arm::getARMFloatABI(
         getToolChain().getDriver(), Args, getToolChain().getTriple());
     CmdArgs.push_back(Args.MakeArgString("-mfloat-abi=" + ARMFloatABI));
 
     Args.AddLastArg(CmdArgs, options::OPT_march_EQ);
 
     // FIXME: remove krait check when GNU tools support krait cpu
     // for now replace it with -march=armv7-a  to avoid a lower
     // march from being picked in the absence of a cpu flag.
     Arg *A;
     if ((A = Args.getLastArg(options::OPT_mcpu_EQ)) &&
       StringRef(A->getValue()) == "krait")
         CmdArgs.push_back("-march=armv7-a");
     else
       Args.AddLastArg(CmdArgs, options::OPT_mcpu_EQ);
     Args.AddLastArg(CmdArgs, options::OPT_mfpu_EQ);
-  } else if (getToolChain().getArch() == llvm::Triple::mips ||
-             getToolChain().getArch() == llvm::Triple::mipsel ||
-             getToolChain().getArch() == llvm::Triple::mips64 ||
-             getToolChain().getArch() == llvm::Triple::mips64el) {
+    break;
+  }
+  case llvm::Triple::mips:
+  case llvm::Triple::mipsel:
+  case llvm::Triple::mips64:
+  case llvm::Triple::mips64el: {
     StringRef CPUName;
     StringRef ABIName;
     mips::getMipsCPUAndABI(Args, getToolChain().getTriple(), CPUName, ABIName);
     ABIName = getGnuCompatibleMipsABIName(ABIName);
 
     CmdArgs.push_back("-march");
     CmdArgs.push_back(CPUName.data());
 
case llvm::Triple::mips64el: {
 
     Args.AddLastArg(CmdArgs, options::OPT_mhard_float,
                     options::OPT_msoft_float);
 
     Args.AddLastArg(CmdArgs, options::OPT_modd_spreg,
                     options::OPT_mno_odd_spreg);
 
     NeedsKPIC = true;
-  } else if (getToolChain().getArch() == llvm::Triple::systemz) {
+    break;
+  }
+  case llvm::Triple::systemz: {
     // Always pass an -march option, since our default of z10 is later
     // than the GNU assembler's default.
     StringRef CPUName = getSystemZTargetCPU(Args);
     CmdArgs.push_back(Args.MakeArgString("-march=" + CPUName));
+    break;
+  }
   }
 
   if (NeedsKPIC)
     addAssemblerKPIC(Args, CmdArgs);
 
   Args.AddAllArgValues(CmdArgs, options::OPT_Wa_COMMA,
                        options::OPT_Xassembler);