[Clang][MIPS] Create specific targets for MIPS PE/COFF (#121040)

Implement GNU and MSVC variants.
When using them, _WIN32 and _M_MRX000/_MIPS_ macros are correctly
defined.

Author: hpoussin

clang/lib/Basic/Targets.cpp

@@ -297,6 +297,14 @@ std::unique_ptr<TargetInfo> AllocateTarget(const llvm::Triple &Triple,
     case llvm::Triple::NaCl:
       return std::make_unique<NaClTargetInfo<NaClMips32TargetInfo>>(Triple,
                                                                     Opts);
+    case llvm::Triple::Win32:
+      switch (Triple.getEnvironment()) {
+      case llvm::Triple::GNU:
+        return std::make_unique<MinGWMipsTargetInfo>(Triple, Opts);
+      case llvm::Triple::MSVC:
+      default: // Assume MSVC for unknown environments
+        return std::make_unique<MicrosoftMipsTargetInfo>(Triple, Opts);
+      }
     default:
       return std::make_unique<MipsTargetInfo>(Triple, Opts);
     }

clang/lib/Basic/Targets/Mips.cpp

@@ -304,3 +304,62 @@ bool MipsTargetInfo::validateTarget(DiagnosticsEngine &Diags) const {
 
   return true;
 }
+
+WindowsMipsTargetInfo::WindowsMipsTargetInfo(const llvm::Triple &Triple,
+                                             const TargetOptions &Opts)
+    : WindowsTargetInfo<MipsTargetInfo>(Triple, Opts), Triple(Triple) {}
+
+void WindowsMipsTargetInfo::getVisualStudioDefines(
+    const LangOptions &Opts, MacroBuilder &Builder) const {
+  Builder.defineMacro("_M_MRX000", "4000");
+}
+
+TargetInfo::BuiltinVaListKind
+WindowsMipsTargetInfo::getBuiltinVaListKind() const {
+  return TargetInfo::CharPtrBuiltinVaList;
+}
+
+TargetInfo::CallingConvCheckResult
+WindowsMipsTargetInfo::checkCallingConvention(CallingConv CC) const {
+  switch (CC) {
+  case CC_X86StdCall:
+  case CC_X86ThisCall:
+  case CC_X86FastCall:
+  case CC_X86VectorCall:
+    return CCCR_Ignore;
+  case CC_C:
+  case CC_OpenCLKernel:
+  case CC_PreserveMost:
+  case CC_PreserveAll:
+  case CC_Swift:
+  case CC_SwiftAsync:
+    return CCCR_OK;
+  default:
+    return CCCR_Warning;
+  }
+}
+
+// Windows MIPS, MS (C++) ABI
+MicrosoftMipsTargetInfo::MicrosoftMipsTargetInfo(const llvm::Triple &Triple,
+                                                 const TargetOptions &Opts)
+    : WindowsMipsTargetInfo(Triple, Opts) {
+  TheCXXABI.set(TargetCXXABI::Microsoft);
+}
+
+void MicrosoftMipsTargetInfo::getTargetDefines(const LangOptions &Opts,
+                                               MacroBuilder &Builder) const {
+  WindowsMipsTargetInfo::getTargetDefines(Opts, Builder);
+  WindowsMipsTargetInfo::getVisualStudioDefines(Opts, Builder);
+}
+
+MinGWMipsTargetInfo::MinGWMipsTargetInfo(const llvm::Triple &Triple,
+                                         const TargetOptions &Opts)
+    : WindowsMipsTargetInfo(Triple, Opts) {
+  TheCXXABI.set(TargetCXXABI::GenericMIPS);
+}
+
+void MinGWMipsTargetInfo::getTargetDefines(const LangOptions &Opts,
+                                           MacroBuilder &Builder) const {
+  WindowsMipsTargetInfo::getTargetDefines(Opts, Builder);
+  Builder.defineMacro("_MIPS_");
+}

clang/lib/Basic/Targets/Mips.h

@@ -13,6 +13,7 @@
 #ifndef LLVM_CLANG_LIB_BASIC_TARGETS_MIPS_H
 #define LLVM_CLANG_LIB_BASIC_TARGETS_MIPS_H
 
+#include "OSTargets.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Basic/TargetOptions.h"
 #include "llvm/Support/Compiler.h"
@@ -450,6 +451,42 @@ class LLVM_LIBRARY_VISIBILITY MipsTargetInfo : public TargetInfo {
     return std::make_pair(32, 32);
   }
 };
+
+class LLVM_LIBRARY_VISIBILITY WindowsMipsTargetInfo
+    : public WindowsTargetInfo<MipsTargetInfo> {
+  const llvm::Triple Triple;
+
+public:
+  WindowsMipsTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts);
+
+  void getVisualStudioDefines(const LangOptions &Opts,
+                              MacroBuilder &Builder) const;
+
+  BuiltinVaListKind getBuiltinVaListKind() const override;
+
+  CallingConvCheckResult checkCallingConvention(CallingConv CC) const override;
+};
+
+// Windows MIPS, MS (C++) ABI
+class LLVM_LIBRARY_VISIBILITY MicrosoftMipsTargetInfo
+    : public WindowsMipsTargetInfo {
+public:
+  MicrosoftMipsTargetInfo(const llvm::Triple &Triple,
+                          const TargetOptions &Opts);
+
+  void getTargetDefines(const LangOptions &Opts,
+                        MacroBuilder &Builder) const override;
+};
+
+// MIPS MinGW target
+class LLVM_LIBRARY_VISIBILITY MinGWMipsTargetInfo
+    : public WindowsMipsTargetInfo {
+public:
+  MinGWMipsTargetInfo(const llvm::Triple &Triple, const TargetOptions &Opts);
+
+  void getTargetDefines(const LangOptions &Opts,
+                        MacroBuilder &Builder) const override;
+};
 } // namespace targets
 } // namespace clang
 

clang/test/Preprocessor/predefined-win-macros.c

@@ -113,6 +113,13 @@
 // CHECK-ARM64EC-WIN: #define _WIN32 1
 // CHECK-ARM64EC-WIN: #define _WIN64 1
 
+// RUN: %clang_cc1 -triple mipsel-windows %s -E -dM -o - \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-MIPSEL-WIN
+
+// CHECK-MIPSEL-WIN: #define _M_MRX000 4000
+// CHECK-MIPSEL-WIN: #define _WIN32 1
+// CHECK-MIPSEL-WIN-NOT: #define _MIPS_ 1
+
 // RUN: %clang_cc1 -triple i686-windows-gnu %s -E -dM -o - \
 // RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-X86-MINGW
 
@@ -173,3 +180,12 @@
 // CHECK-ARM64EC-MINGW: #define __arm64ec__ 1
 // CHECK-ARM64EC-MINGW: #define __x86_64 1
 // CHECK-ARM64EC-MINGW: #define __x86_64__ 1
+
+// RUN: %clang_cc1 -triple mipsel-windows-gnu %s -E -dM -o - \
+// RUN:   | FileCheck -match-full-lines %s --check-prefix=CHECK-MIPSEL-MINGW
+
+// CHECK-MIPSEL-MINGW-NOT: #define _M_MRX000 4000
+// CHECK-MIPSEL-MINGW: #define _MIPS_ 1
+// CHECK-MIPSEL-MINGW: #define _WIN32 1
+// CHECK-MIPSEL-MINGW: #define __mips 32
+// CHECK-MIPSEL-MINGW: #define __mips__ 1