[mips] Added support for -Wa,-mips32 and similar.

[dsanders]

lib/Driver/Tools.cpp

2501–2524

We don't quite do the right thing when we get multiple -mips* options. For -Wa,-mips64r2,-mips4 we don't undo the effect of the '-target-feature +mips64r2' when we process the -mips4. As a result, the selected target is mips64r2 whereas GAS would select mips4.

We can't fix this by adding a '-target-feature -mips64r2' since would select mips64 so we'll need to wait until we've seen all the '-Wa,' arguments before we add the -target-feature (similar to --compress-debug-sections).

2506–2507

There should be a mips5 case too.

test/Driver/mips-ias-Wa.s

66–74

There should be a mips5 case too

121–129

These two tests aren't quite right since the selected target is the maximum of the three at the moment.

[s.egerton]

Responded to reviewers comments.

The -mips* option is now saved until all arguments have been parsed. The last -mips* option is the only one pushed back.
The tests are now updated to check that multiple -target-feature -mips* options are not present.

[dsanders]

With a couple small changes it will LGTM

lib/Driver/Tools.cpp

2572–2573

It would be better to use a null pointer check and use nullptr instead of the empty strings in the initial and default cases.

test/Driver/mips-ias-Wa.s

121–129

You need to check the CHECK-NOT's on both sides of the CHECK.

lib/Driver/Tools.cpp

for (StringRef Value : A->getValues()) {
           CmdArgs.push_back("+soft-float");
           continue;
         }
         if (Value.startswith("-mhard-float")) {
           CmdArgs.push_back("-target-feature");
           CmdArgs.push_back("-soft-float");
           continue;
         }
+
+        const char *Feature = llvm::StringSwitch<const char *>(Value)
+                                  .Case("-mips1", "+mips1")
+                                  .Case("-mips2", "+mips2")
+                                  .Case("-mips3", "+mips3")
+                                  .Case("-mips4", "+mips4")
+                                  .Case("-mips32", "+mips32")
+                                  .Case("-mips32r2", "+mips32r2")
+                                  .Case("-mips32r3", "+mips32r3")
+                                  .Case("-mips32r5", "+mips32r5")
+                                  .Case("-mips32r6", "+mips32r6")
+                                  .Case("-mips64", "+mips64")
+                                  .Case("-mips64r2", "+mips64r2")
+                                  .Case("-mips64r3", "+mips64r3")
+                                  .Case("-mips64r5", "+mips64r5")
+                                  .Case("-mips64r6", "+mips64r6")
+                                  .Default("");
+
+        StringRef FeatureStringRef = Feature;
+        if (FeatureStringRef != "") {
+          CmdArgs.push_back("-target-feature");
+          CmdArgs.push_back(Feature);
+          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") {
for (const Arg *A :
     }
   }
   if (CompressDebugSections) {
     if (llvm::zlib::isAvailable())
       CmdArgs.push_back("-compress-debug-sections");
     else
       D.Diag(diag::warn_debug_compression_unavailable);
   }
 }
 
 // This adds the static libclang_rt.builtins-arch.a directly to the command line
 // FIXME: Make sure we can also emit shared objects if they're requested
 // and available, check for possible errors, etc.
 static void addClangRT(const ToolChain &TC, const ArgList &Args,
                        ArgStringList &CmdArgs) {
   CmdArgs.push_back(TC.getCompilerRTArgString(Args, "builtins"));
 }
 

test/Driver/mips-ias-Wa.s

 // RUN:   FileCheck -check-prefix=MSOFT-FLOAT-BOTH-MSOFT-FLOAT-FIRST %s
 // MSOFT-FLOAT-BOTH-MSOFT-FLOAT-FIRST: -cc1as
 // MSOFT-FLOAT-BOTH-MSOFT-FLOAT-FIRST: "-target-feature" "+soft-float" "-target-feature" "-soft-float"
 
 // RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mhard-float,-msoft-float 2>&1 | \
 // RUN:   FileCheck -check-prefix=MSOFT-FLOAT-BOTH-MHARD-FLOAT-FIRST %s
 // MSOFT-FLOAT-BOTH-MHARD-FLOAT-FIRST: -cc1as
 // MSOFT-FLOAT-BOTH-MHARD-FLOAT-FIRST: "-target-feature" "-soft-float" "-target-feature" "+soft-float"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips1 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS1 %s
+// MIPS1: -cc1as
+// MIPS1: "-target-feature" "+mips1"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips2 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS2 %s
+// MIPS2: -cc1as
+// MIPS2: "-target-feature" "+mips2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips3 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS3 %s
+// MIPS3: -cc1as
+// MIPS3: "-target-feature" "+mips3"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips4 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS4 %s
+// MIPS4: -cc1as
+// MIPS4: "-target-feature" "+mips4"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips32 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS32 %s
+// MIPS32: -cc1as
+// MIPS32: "-target-feature" "+mips32"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips32r2 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS32R2 %s
+// MIPS32R2: -cc1as
+// MIPS32R2: "-target-feature" "+mips32r2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips32r3 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS32R3 %s
+// MIPS32R3: -cc1as
+// MIPS32R3: "-target-feature" "+mips32r3"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips32r5 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS32R5 %s
+// MIPS32R5: -cc1as
+// MIPS32R5: "-target-feature" "+mips32r5"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips32r6 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS32R6 %s
+// MIPS32R6: -cc1as
+// MIPS32R6: "-target-feature" "+mips32r6"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64 %s
+// MIPS64: -cc1as
+// MIPS64: "-target-feature" "+mips64"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64r2 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64R2 %s
+// MIPS64R2: -cc1as
+// MIPS64R2: "-target-feature" "+mips64r2"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64r3 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64R3 %s
+// MIPS64R3: -cc1as
+// MIPS64R3: "-target-feature" "+mips64r3"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64r5 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64R5 %s
+// MIPS64R5: -cc1as
+// MIPS64R5: "-target-feature" "+mips64r5"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64r6 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64R6 %s
+// MIPS64R6: -cc1as
+// MIPS64R6: "-target-feature" "+mips64r6"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64r2,-mips4 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64R2-MIPS4 %s
+// MIPS64R2-MIPS4: -cc1as
+// MIPS64R2-MIPS4: "-target-feature" "+mips4"
+
+// RUN: %clang -target mips-linux-gnu -### -fintegrated-as -c %s -Wa,-mips64,-mips32,-mips32r2 2>&1 | \
+// RUN:   FileCheck -check-prefix=MIPS64-MIPS32-MIPS32R2 %s
+// MIPS64-MIPS32-MIPS32R2: -cc1as
+// MIPS64-MIPS32-MIPS32R2: "-target-feature" "+mips32r2"