[mips] Separated mips specific -Wa options, so that they are not checked on other platforms.

[s.egerton]

Summary

This is a follow on to post review comments on revision r248276.

[dsanders]

+Renato and Joerg

I was going to say I think it's ok and the optimizer should be smart enough to factor out the common IsMips check but I've just realized there may be a better way. The current code is using an else after an (implicit) continue. If we made that continue explicit, we could make this code a bit neater and have a place to add target specific options.

I'm thinking something like:

for (...) {
  ...

  auto Arch = C.getDefaultToolChain().getArch();

  if (C.getDefaultToolChain().getArch() == llvm::Triple::mips ||
      C.getDefaultToolChain().getArch() == llvm::Triple::mipsel ||
      C.getDefaultToolChain().getArch() == llvm::Triple::mips64 ||
      C.getDefaultToolChain().getArch() == llvm::Triple::mips64el)
    if (mips::CollectArgsForIntegratedAssembler(...)
      continue;

  if (Value == "-force_cpusubtype_ALL")
    continue;

  ...

  D.Diag(diag::err_drv_unsupported_option_argument)
      << A->getOption().getName() << Value;
}

Thoughts?

[s.egerton]

Responded to comments made on the mailing list.

[dsanders]

LGTM

lib/Driver/Tools.cpp

for (const Arg *A :
 
     for (StringRef Value : A->getValues()) {
       if (TakeNextArg) {
         CmdArgs.push_back(Value.data());
         TakeNextArg = false;
         continue;
       }
 
-      bool IsMips = C.getDefaultToolChain().getArch() == llvm::Triple::mips ||
-                    C.getDefaultToolChain().getArch() == llvm::Triple::mipsel ||
-                    C.getDefaultToolChain().getArch() == llvm::Triple::mips64 ||
-                    C.getDefaultToolChain().getArch() == llvm::Triple::mips64el;
+      switch (C.getDefaultToolChain().getArch()) {
+      default:
+        break;
+      case llvm::Triple::mips:
+      case llvm::Triple::mipsel:
+      case llvm::Triple::mips64:
+      case llvm::Triple::mips64el:
+        if (Value == "--trap") {
+          CmdArgs.push_back("-target-feature");
+          CmdArgs.push_back("+use-tcc-in-div");
+          continue;
+        }
+        if (Value == "--break") {
+          CmdArgs.push_back("-target-feature");
+          CmdArgs.push_back("-use-tcc-in-div");
+          continue;
+        }
+        if (Value.startswith("-msoft-float")) {
+          CmdArgs.push_back("-target-feature");
+          CmdArgs.push_back("+soft-float");
+          continue;
+        }
+        if (Value.startswith("-mhard-float")) {
+          CmdArgs.push_back("-target-feature");
+          CmdArgs.push_back("-soft-float");
+          continue;
+        }
+        break;
+      }
 
       if (Value == "-force_cpusubtype_ALL") {
         // Do nothing, this is the default and we don't support anything else.
       } else if (Value == "-L") {
         CmdArgs.push_back("-msave-temp-labels");
       } else if (Value == "--fatal-warnings") {
         CmdArgs.push_back("-massembler-fatal-warnings");
       } else if (Value == "--noexecstack") {
for (StringRef Value : A->getValues()) {
         // -I. The next arg will be the include directory.
         if (Value == "-I")
           TakeNextArg = true;
       } else if (Value.startswith("-gdwarf-")) {
         CmdArgs.push_back(Value.data());
       } else if (Value.startswith("-mcpu") || Value.startswith("-mfpu") ||
                  Value.startswith("-mhwdiv") || Value.startswith("-march")) {
         // Do nothing, we'll validate it later.
-      } else if (IsMips && Value == "--trap") {
-        CmdArgs.push_back("-target-feature");
-        CmdArgs.push_back("+use-tcc-in-div");
-      } else if (IsMips && Value == "--break") {
-        CmdArgs.push_back("-target-feature");
-        CmdArgs.push_back("-use-tcc-in-div");
-      } else if (IsMips && Value.startswith("-msoft-float")) {
-        CmdArgs.push_back("-target-feature");
-        CmdArgs.push_back("+soft-float");
-      } else if (IsMips && Value.startswith("-mhard-float")) {
-        CmdArgs.push_back("-target-feature");
-        CmdArgs.push_back("-soft-float");
       } else {
         D.Diag(diag::err_drv_unsupported_option_argument)
             << A->getOption().getName() << Value;
       }
     }
   }
   if (CompressDebugSections) {
     if (llvm::zlib::isAvailable())