[SystemZ][z/OS] Set default wchar_t type for zOS

[abhina.sreeskantharajan]

Summary

Set the default wchar_t type on z/OS, and unsigned as the default.

[fanbo-meng]

LGTM

[hubert.reinterpretcast]

LGTM.

clang/lib/Basic/Targets/OSTargets.h

if (Opts.CPlusPlus && Opts.WChar) {
       Builder.defineMacro("__wchar_t");
     }
 
     this->PlatformName = llvm::Triple::getOSTypeName(Triple.getOS());
   }
 
 public:
   ZOSTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts)
-      : OSTargetInfo<Target>(Triple, Opts) {}
+      : OSTargetInfo<Target>(Triple, Opts) {
+    this->WCharType = TargetInfo::UnsignedInt;
+  }
 };
 
 void addWindowsDefines(const llvm::Triple &Triple, const LangOptions &Opts,
                        MacroBuilder &Builder);
 
 // Windows target
 template <typename Target>
 class LLVM_LIBRARY_VISIBILITY WindowsTargetInfo : public OSTargetInfo<Target> {

clang/lib/Driver/ToolChains/Clang.cpp

static void RenderCharacterOptions(const ArgList &Args, const llvm::Triple &T,
   if (const Arg *A = Args.getLastArg(options::OPT_fshort_wchar,
                                      options::OPT_fno_short_wchar)) {
     if (A->getOption().matches(options::OPT_fshort_wchar)) {
       CmdArgs.push_back("-fwchar-type=short");
       CmdArgs.push_back("-fno-signed-wchar");
     } else {
       bool IsARM = T.isARM() || T.isThumb() || T.isAArch64();
       CmdArgs.push_back("-fwchar-type=int");
-      if (IsARM && !(T.isOSWindows() || T.isOSNetBSD() ||
-                     T.isOSOpenBSD()))
+      if (T.isOSzOS() ||
+          (IsARM && !(T.isOSWindows() || T.isOSNetBSD() || T.isOSOpenBSD())))
         CmdArgs.push_back("-fno-signed-wchar");
       else
         CmdArgs.push_back("-fsigned-wchar");
     }
   }
 }
 
 static void RenderObjCOptions(const ToolChain &TC, const Driver &D,

clang/test/CodeGen/wchar-size.c

 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -o - %s | FileCheck %s -check-prefix=LONG-WCHAR
 // RUN: %clang_cc1 -triple x86_64-unknown-windows-msvc -emit-llvm -o - %s | FileCheck %s -check-prefix=SHORT-WCHAR
 // RUN: %clang_cc1 -triple x86_64-unknown-linux-gnu -emit-llvm -o - -fwchar-type=short -fno-signed-wchar %s | FileCheck %s -check-prefix=SHORT-WCHAR
+// RUN: %clang_cc1 -triple s390x-none-zos -emit-llvm -o - %s | FileCheck %s -check-prefix=LONG-WCHAR
 // Note: -fno-short-wchar implies the target default is used; so there is no
 // need to test this separately here.
 
 // LONG-WCHAR: !{{[0-9]+}} = !{i32 {{[0-9]+}}, !"wchar_size", i32 4}
 // SHORT-WCHAR: !{{[0-9]+}} = !{i32 {{[0-9]+}}, !"wchar_size", i32 2}

clang/test/Lexer/wchar-signedness.c

 // RUN: %clang_cc1 -fsyntax-only -dM -E %s -triple x86_64-none-linux-gnu | FileCheck %s --check-prefix=CHECK-X86
 // RUN: %clang_cc1 -fsyntax-only -dM -E %s -triple armv7-none-eabi | FileCheck %s --check-prefix=CHECK-ARM
 // RUN: %clang_cc1 -fsyntax-only -dM -E %s -triple thumbv7-none-eabi | FileCheck %s --check-prefix=CHECK-ARM
+// RUN: %clang_cc1 -fsyntax-only -dM -E %s -triple s390x-none-zos | FileCheck %s --check-prefix=CHECK-ZOS
 
 // CHECK-X86-NOT: #define __WCHAR_UNSIGNED__
 // CHECK-X86: #define __WINT_UNSIGNED__ 1
 
 // CHECK-ARM: #define __WCHAR_UNSIGNED__ 1
 // CHECK-ARM-NOT: #define __WINT_UNSIGNED__ 1
+
+// CHECK-ZOS: #define __WCHAR_UNSIGNED__ 1
+// CHECK-ZOS-NOT: #define __WINT_UNSIGNED__ 1

clang/test/Preprocessor/wchar_t.c

 // CHECK-ARM64-OPENBSD-DAG: #define __WCHAR_TYPE__ int
 // CHECK-ARM64-OPENBSD-NOT: #define __WCHAR_UNSIGNED__ 0
 
 // RUN: %clang_cc1 -triple aarch64-unknown-none -fwchar-type=int -fno-signed-wchar -dM -E %s -o - | FileCheck %s -check-prefix CHECK-ARM64-AAPCS64
 // CHECK-ARM64-AAPCS64-DAG: #define __WCHAR_MAX__ 4294967295U
 // CHECK-ARM64-AAPCS64-DAG: #define __WCHAR_TYPE__ unsigned int
 // CHECK-ARM64-AAPCS64-DAG: #define __WCHAR_UNSIGNED__ 1
 
+// RUN: %clang_cc1 -triple s390x-none-zos -fwchar-type=int -fno-signed-wchar -dM -E %s -o - | FileCheck %s -check-prefix CHECK-ZOS
+// CHECK-ZOS: #define __WCHAR_MAX__ 4294967295U
+// CHECK-ZOS: #define __WCHAR_TYPE__ unsigned int
+// CHECK-ZOS: #define __WCHAR_UNSIGNED__ 1
+
 // RUN: %clang_cc1 -triple xcore-unknown-unknown -fwchar-type=char -fno-signed-wchar -dM -E %s -o - | FileCheck %s -check-prefix CHECK-XCORE
 // CHECK-XCORE-DAG: #define __WCHAR_MAX__ 255
 // CHECK-XCORE-DAG: #define __WCHAR_TYPE__ unsigned char
 // CHECK-XCORE-DAG: #define __WCHAR_UNSIGNED__ 1
 
 // RUN: %clang_cc1 -triple x86_64-unknown-windows-cygnus -fwchar-type=short -fno-signed-wchar -dM -E %s -o - | FileCheck %s -check-prefix CHECK-CYGWIN-X64
 // CHECK-CYGWIN-X64-DAG: #define __WCHAR_MAX__ 65535
 // CHECK-CYGWIN-X64-DAG: #define __WCHAR_TYPE__ unsigned short

clang/test/Sema/wchar.c

 // RUN: %clang_cc1 %s -fsyntax-only -verify
 // RUN: %clang_cc1 %s -fsyntax-only -fwchar-type=short -fno-signed-wchar -verify -DSHORT_WCHAR
 
 typedef __WCHAR_TYPE__ wchar_t;
 
 #if defined(_WIN32) || defined(_M_IX86) || defined(__CYGWIN__) \
  || defined(_M_X64) || defined(__ORBIS__) || defined(SHORT_WCHAR)
   #define WCHAR_T_TYPE unsigned short
-#elif defined(__arm) || defined(__aarch64__)
+#elif defined(__arm) || defined(__aarch64__) || defined(__MVS__)
   #define WCHAR_T_TYPE unsigned int
 #elif defined(__sun)
   #if defined(__LP64__)
     #define WCHAR_T_TYPE int
   #else
     #define WCHAR_T_TYPE long
   #endif
 #else /* Solaris. */