ARM: Default to apcs-gnu ABI for NetBSD

[olista01]

Summary

r216662 changed the default ABi for 32-bit ARM targets to be "aapcs" when no environment is given in the triple, however NetBSD requires it to be "apcs-gnu".

[olista01]

Allow all environments for NetBSD.

Is the trailing - in the triple intentional?

Yes, the triple has four parts (the environment comes after the last "-") and I'm not trying to test the triple parser here.

[olista01]

This was accepted by email, but did not reach Phab.

[olista01]

Committed revision 217141.

lib/Driver/Tools.cpp

if (Arg *A = Args.getLastArg(options::OPT_mabi_EQ)) {
     switch(Triple.getEnvironment()) {
     case llvm::Triple::Android:
     case llvm::Triple::GNUEABI:
     case llvm::Triple::GNUEABIHF:
       ABIName = "aapcs-linux";
       break;
     case llvm::Triple::EABIHF:
     case llvm::Triple::EABI:
+      ABIName = "aapcs";
+      break;
     default:
+      if (Triple.getOS() == llvm::Triple::NetBSD)
+        ABIName = "apcs-gnu";
+      else
         ABIName = "aapcs";
       break;
     }
   }
   CmdArgs.push_back("-target-abi");
   CmdArgs.push_back(ABIName);
 
   // Determine floating point ABI from the options & target defaults.
   StringRef FloatABI = tools::arm::getARMFloatABI(D, Args, Triple);

test/Driver/arm-abi.c

 // RUN:   | FileCheck -check-prefix=CHECK-APCS-GNU %s
 // RUN: %clang -target thumb--darwin- -arch armv7m %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-AAPCS %s
 
 // Windows targets default to AAPCS, regardless of environment
 // RUN: %clang -target arm--windows-gnueabi %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-AAPCS %s
 
+// NetBSD defaults to apcs-gnu, but can also use aapcs
+// RUN: %clang -target arm--netbsd- %s -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-APCS-GNU %s
+// RUN: %clang -target arm--netbsd-eabi %s -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-AAPCS %s
+// RUN: %clang -target arm--netbsd-eabihf %s -### -o %t.o 2>&1 \
+// RUN:   | FileCheck -check-prefix=CHECK-AAPCS %s
+
 // Otherwise, ABI is celected based on environment
 // RUN: %clang -target arm---android %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
 // RUN: %clang -target arm---gnueabi %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
 // RUN: %clang -target arm---gnueabihf %s -### -o %t.o 2>&1 \
 // RUN:   | FileCheck -check-prefix=CHECK-AAPCS-LINUX %s
 // RUN: %clang -target arm---eabi %s -### -o %t.o 2>&1 \