Add HLSL Language Option and Preprocessor

[beanz]

Summary

Bringing in HLSL as a language as well as language options for each of
the HLSL language standards.

While the HLSL language is unimplemented, this patch adds the
HLSL-specific preprocessor defines which enables testing of the command
line options through the driver.

[pete]

LGTM

[rnk]

lgtm

clang/lib/Frontend/InitPreprocessor.cpp

401–403

This here suggests that the order of the HLSL environments in the triple really, really matter, since we expose them to users. That's really surprising: it means small changes in LLVM affect this pre-processor macro in surprising ways. I see the test for this, but what do you think about adding a static_assert to Triple.cpp to move the check into LLVM? Something like:

static_assert(Triple::Compute - Triple::Pixel == 1, "incorrect HLSL env order");
static_assert(Triple::Amplification - Triple::Pixel == 2, "incorrect HLSL env order");

Maybe this is addressed elsewhere, I haven't looked at all patches holistically.

[beanz]

clang/lib/Frontend/InitPreprocessor.cpp

401–403

This is more or less verified by the test case checking the preprocessor values, but static_asserts would provide a more clear error, so I'll add some.

[erichkeane]

clang/lib/Frontend/InitPreprocessor.cpp

401

Why does this do a double-assign here? Is th ere supposed to be a 2nd variable here? Otherwise this is likely not particularly well-defined behavior.

[beanz]

clang/lib/Frontend/InitPreprocessor.cpp

401

I must have screwed this up in rebating one of the patches. Will fix ASAP.

clang/include/clang/Basic/LangOptions.h

#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
   unsigned Name : Bits;
 #include "clang/Basic/LangOptions.def"
 };
 
 /// In the Microsoft ABI, this controls the placement of virtual displacement
 /// members used to implement virtual inheritance.
 enum class MSVtorDispMode { Never, ForVBaseOverride, ForVFTable };
 
+/// Shader programs run in specific pipeline stages.
+enum class ShaderStage {
+  Pixel = 0,
+  Vertex,
+  Geometry,
+  Hull,
+  Domain,
+  Compute,
+  Library,
+  RayGeneration,
+  Intersection,
+  AnyHit,
+  ClosestHit,
+  Miss,
+  Callable,
+  Mesh,
+  Amplification,
+  Invalid,
+};
+
 /// Keeps track of the various options that can be
 /// enabled, which controls the dialect of C or C++ that is accepted.
 class LangOptions : public LangOptionsBase {
 public:
   using Visibility = clang::Visibility;
   using RoundingMode = llvm::RoundingMode;
 
   enum GCMode { NonGC, GCOnly, HybridGC };
enum SYCLMajorVersion {
     SYCL_None,
     SYCL_2017,
     SYCL_2020,
     // The "default" SYCL version to be used when none is specified on the
     // frontend command line.
     SYCL_Default = SYCL_2020
   };
 
+  enum HLSLLangStd {
+    HLSL_Unset = 0,
+    HLSL_2015 = 2015,
+    HLSL_2016 = 2016,
+    HLSL_2017 = 2017,
+    HLSL_2018 = 2018,
+    HLSL_2021 = 2021,
+    HLSL_202x = 2029,
+  };
+
   /// Clang versions with different platform ABI conformance.
   enum class ClangABI {
     /// Attempt to be ABI-compatible with code generated by Clang 3.8.x
     /// (SVN r257626). This causes <1 x long long> to be passed in an
     /// integer register instead of an SSE register on x64_64.
     Ver3_8,
 
     /// Attempt to be ABI-compatible with code generated by Clang 4.0.x

clang/include/clang/Basic/LangOptions.def

 LANGOPT(OpenMPTargetDebug , 32, 0, "Enable debugging in the OpenMP offloading device RTL")
 LANGOPT(OpenMPOptimisticCollapse  , 1, 0, "Use at most 32 bits to represent the collapsed loop nest counter.")
 LANGOPT(OpenMPThreadSubscription  , 1, 0, "Assume work-shared loops do not have more iterations than participating threads.")
 LANGOPT(OpenMPTeamSubscription  , 1, 0, "Assume distributed loops do not have more iterations than participating teams.")
 LANGOPT(OpenMPNoThreadState  , 1, 0, "Assume that no thread in a parallel region will modify an ICV.")
 LANGOPT(OpenMPOffloadMandatory  , 1, 0, "Assert that offloading is mandatory and do not create a host fallback.")
 LANGOPT(RenderScript      , 1, 0, "RenderScript")
 
+LANGOPT(HLSL, 1, 0, "HLSL")
+ENUM_LANGOPT(HLSLVersion, HLSLLangStd, 16, HLSL_Unset, "HLSL Version")
+
 LANGOPT(CUDAIsDevice      , 1, 0, "compiling for CUDA device")
 LANGOPT(CUDAAllowVariadicFunctions, 1, 0, "allowing variadic functions in CUDA device code")
 LANGOPT(CUDAHostDeviceConstexpr, 1, 1, "treating unattributed constexpr functions as __host__ __device__")
 LANGOPT(CUDADeviceApproxTranscendentals, 1, 0, "using approximate transcendental functions")
 LANGOPT(GPURelocatableDeviceCode, 1, 0, "generate relocatable device code")
 LANGOPT(GPUAllowDeviceInit, 1, 0, "allowing device side global init functions for HIP")
 LANGOPT(GPUMaxThreadsPerBlock, 32, 1024, "default max threads per block for kernel launch bounds for HIP")
 LANGOPT(GPUDeferDiag, 1, 0, "defer host/device related diagnostic messages for CUDA/HIP")

clang/include/clang/Basic/LangStandard.h

enum class Language : uint8_t {
   CXX,
   ObjC,
   ObjCXX,
   OpenCL,
   OpenCLCXX,
   CUDA,
   RenderScript,
   HIP,
+  HLSL,
   ///@}
 };
 
 enum LangFeatures {
   LineComment = (1 << 0),
   C99 = (1 << 1),
   C11 = (1 << 2),
   C17 = (1 << 3),
   C2x = (1 << 4),
   CPlusPlus = (1 << 5),
   CPlusPlus11 = (1 << 6),
   CPlusPlus14 = (1 << 7),
   CPlusPlus17 = (1 << 8),
   CPlusPlus20 = (1 << 9),
   CPlusPlus2b = (1 << 10),
   Digraphs = (1 << 11),
   GNUMode = (1 << 12),
   HexFloat = (1 << 13),
   ImplicitInt = (1 << 14),
-  OpenCL = (1 << 15)
+  OpenCL = (1 << 15),
+  HLSL = (1 << 16)
 };
 
 /// LangStandard - Information about the properties of a particular language
 /// standard.
 struct LangStandard {
   enum Kind {
 #define LANGSTANDARD(id, name, lang, desc, features) \
     lang_##id,

clang/include/clang/Basic/LangStandards.def

 // CUDA
 LANGSTANDARD(cuda, "cuda", CUDA, "NVIDIA CUDA(tm)",
              LineComment | CPlusPlus | CPlusPlus11 | CPlusPlus14 | Digraphs)
 
 // HIP
 LANGSTANDARD(hip, "hip", HIP, "HIP",
              LineComment | CPlusPlus | CPlusPlus11 | CPlusPlus14 | Digraphs)
 
+// HLSL
+LANGSTANDARD(hlsl, "hlsl",
+             HLSL, "High Level Shader Language",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl2015, "hlsl2015",
+             HLSL, "High Level Shader Language 2015",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl2016, "hlsl2016",
+             HLSL, "High Level Shader Language 2016",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl2017, "hlsl2017",
+             HLSL, "High Level Shader Language 2017",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl2018, "hlsl2018",
+             HLSL, "High Level Shader Language 2018",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl2021, "hlsl2021",
+             HLSL, "High Level Shader Language 2021",
+             LineComment | HLSL | CPlusPlus )
+
+LANGSTANDARD(hlsl202x, "hlsl202x",
+             HLSL, "High Level Shader Language 202x",
+             LineComment | HLSL | CPlusPlus | CPlusPlus11)
+
+
 #undef LANGSTANDARD
 #undef LANGSTANDARD_ALIAS
 #undef LANGSTANDARD_ALIAS_DEPR

clang/include/clang/Driver/Types.def

 TYPE("objc-cpp-output",          PP_ObjC_Alias, INVALID,        "mi",     phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("objective-c",              ObjC,         PP_ObjC,         "m",      phases::Preprocess, phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("c++-cpp-output",           PP_CXX,       INVALID,         "ii",     phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("c++",                      CXX,          PP_CXX,          "cpp",    phases::Preprocess, phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("objective-c++-cpp-output", PP_ObjCXX,    INVALID,         "mii",    phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("objc++-cpp-output",        PP_ObjCXX_Alias, INVALID,      "mii",    phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("objective-c++",            ObjCXX,       PP_ObjCXX,       "mm",     phases::Preprocess, phases::Compile, phases::Backend, phases::Assemble, phases::Link)
 TYPE("renderscript",             RenderScript, PP_C,            "rs",     phases::Preprocess, phases::Compile, phases::Backend, phases::Assemble, phases::Link)
+TYPE("hlsl",                     HLSL,         PP_CXX,          "hlsl",   phases::Preprocess, phases::Compile, phases::Backend)
 
 // C family input files to precompile.
 TYPE("c-header-cpp-output",      PP_CHeader,   INVALID,         "i",      phases::Precompile)
 TYPE("c-header",                 CHeader,      PP_CHeader,      "h",      phases::Preprocess, phases::Precompile)
 TYPE("cl-header",                CLHeader,     PP_CHeader,      "h",      phases::Preprocess, phases::Precompile)
 TYPE("objective-c-header-cpp-output", PP_ObjCHeader, INVALID,   "mi",     phases::Precompile)
 TYPE("objective-c-header",       ObjCHeader,   PP_ObjCHeader,   "h",      phases::Preprocess, phases::Precompile)
 TYPE("c++-header-cpp-output",    PP_CXXHeader, INVALID,         "ii",     phases::Precompile)

clang/lib/ExtractAPI/Serialization/SymbolGraphSerializer.cpp

StringRef getLanguageName(const LangOptions &LangOpts) {
   // Unsupported language currently
   case Language::CXX:
   case Language::ObjCXX:
   case Language::OpenCL:
   case Language::OpenCLCXX:
   case Language::CUDA:
   case Language::RenderScript:
   case Language::HIP:
+  case Language::HLSL:
 
   // Languages that the frontend cannot parse and compile
   case Language::Unknown:
   case Language::Asm:
   case Language::LLVM_IR:
     llvm_unreachable("Unsupported language kind");
   }
 

clang/lib/Frontend/CompilerInvocation.cpp

if (Opts.AuxTargetFeatures.hasValue())
     case Language::Unknown:
       assert(Opts.DashX.getFormat() == InputKind::Precompiled &&
              "Generating -x argument for unknown language (not precompiled).");
       Lang = "ast";
       break;
     case Language::LLVM_IR:
       Lang = "ir";
       break;
+    case Language::HLSL:
+      Lang = "hlsl";
+      break;
     }
 
     GenerateArg(Args, OPT_x,
                 Lang + HeaderUnit + Header + ModuleMap + Preprocessed, SA);
   }
 
   // OPT_INPUT has a unique class, generate it directly.
   for (const auto &Input : Opts.Inputs)
DashX = llvm::StringSwitch<InputKind>(XValue)
                 .Case("cl", Language::OpenCL)
                 .Case("clcpp", Language::OpenCLCXX)
                 .Case("cuda", Language::CUDA)
                 .Case("hip", Language::HIP)
                 .Case("c++", Language::CXX)
                 .Case("objective-c", Language::ObjC)
                 .Case("objective-c++", Language::ObjCXX)
                 .Case("renderscript", Language::RenderScript)
+                .Case("hlsl", Language::HLSL)
                 .Default(Language::Unknown);
 
     // "objc[++]-cpp-output" is an acceptable synonym for
     // "objective-c[++]-cpp-output".
     if (DashX.isUnknown() && Preprocessed && !IsHeaderFile && !ModuleMap &&
         HUK == InputKind::HeaderUnit_None)
       DashX = llvm::StringSwitch<InputKind>(XValue)
                   .Case("objc", Language::ObjC)

 #endif
       break;
     case Language::RenderScript:
       LangStd = LangStandard::lang_c99;
       break;
     case Language::HIP:
       LangStd = LangStandard::lang_hip;
       break;
+    case Language::HLSL:
+      LangStd = LangStandard::lang_hlsl2021;
+      break;
     }
   }
 
   const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
   Opts.LangStd = LangStd;
   Opts.LineComment = Std.hasLineComments();
   Opts.C99 = Std.isC99();
   Opts.C11 = Std.isC11();
   Opts.C17 = Std.isC17();
   Opts.C2x = Std.isC2x();
   Opts.CPlusPlus = Std.isCPlusPlus();
   Opts.CPlusPlus11 = Std.isCPlusPlus11();
   Opts.CPlusPlus14 = Std.isCPlusPlus14();
   Opts.CPlusPlus17 = Std.isCPlusPlus17();
   Opts.CPlusPlus20 = Std.isCPlusPlus20();
   Opts.CPlusPlus2b = Std.isCPlusPlus2b();
   Opts.GNUMode = Std.isGNUMode();
   Opts.GNUCVersion = 0;
   Opts.HexFloats = Std.hasHexFloats();
   Opts.ImplicitInt = Std.hasImplicitInt();
 
+  Opts.HLSL = IK.getLanguage() == Language::HLSL;
+
   // Set OpenCL Version.
   Opts.OpenCL = Std.isOpenCL();
   if (LangStd == LangStandard::lang_opencl10)
     Opts.OpenCLVersion = 100;
   else if (LangStd == LangStandard::lang_opencl11)
     Opts.OpenCLVersion = 110;
   else if (LangStd == LangStandard::lang_opencl12)
     Opts.OpenCLVersion = 120;
   else if (LangStd == LangStandard::lang_opencl20)
     Opts.OpenCLVersion = 200;
   else if (LangStd == LangStandard::lang_opencl30)
     Opts.OpenCLVersion = 300;
   else if (LangStd == LangStandard::lang_openclcpp10)
     Opts.OpenCLCPlusPlusVersion = 100;
   else if (LangStd == LangStandard::lang_openclcpp2021)
     Opts.OpenCLCPlusPlusVersion = 202100;
+  else if (LangStd == LangStandard::lang_hlsl2015)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2015;
+  else if (LangStd == LangStandard::lang_hlsl2016)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2016;
+  else if (LangStd == LangStandard::lang_hlsl2017)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2017;
+  else if (LangStd == LangStandard::lang_hlsl2018)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2018;
+  else if (LangStd == LangStandard::lang_hlsl2021)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2021;
+  else if (LangStd == LangStandard::lang_hlsl202x)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_202x;
 
   // OpenCL has some additional defaults.
   if (Opts.OpenCL) {
     Opts.AltiVec = 0;
     Opts.ZVector = 0;
     Opts.setDefaultFPContractMode(LangOptions::FPM_On);
     Opts.OpenCLCPlusPlus = Opts.CPlusPlus;
     Opts.OpenCLPipes = Opts.getOpenCLCompatibleVersion() == 200;
static bool IsInputCompatibleWithStandard(InputKind IK,
   case Language::HIP:
     return S.getLanguage() == Language::CXX || S.getLanguage() == Language::HIP;
 
   case Language::Asm:
     // Accept (and ignore) all -std= values.
     // FIXME: The -std= value is not ignored; it affects the tokenization
     // and preprocessing rules if we're preprocessing this asm input.
     return true;
+
+  case Language::HLSL:
+    return S.getLanguage() == Language::HLSL;
   }
 
   llvm_unreachable("unexpected input language");
 }
 
 /// Get language name for given input kind.
 static StringRef GetInputKindName(InputKind IK) {
   switch (IK.getLanguage()) {
static StringRef GetInputKindName(InputKind IK) {
   case Language::HIP:
     return "HIP";
 
   case Language::Asm:
     return "Asm";
   case Language::LLVM_IR:
     return "LLVM IR";
 
+  case Language::HLSL:
+    return "HLSL";
+
   case Language::Unknown:
     break;
   }
   llvm_unreachable("unknown input language");
 }
 
 void CompilerInvocation::GenerateLangArgs(const LangOptions &Opts,
                                           SmallVectorImpl<const char *> &Args,

clang/lib/Frontend/FrontendActions.cpp

void PrintPreambleAction::ExecuteAction() {
   case Language::C:
   case Language::CXX:
   case Language::ObjC:
   case Language::ObjCXX:
   case Language::OpenCL:
   case Language::OpenCLCXX:
   case Language::CUDA:
   case Language::HIP:
+  case Language::HLSL:
     break;
 
   case Language::Unknown:
   case Language::Asm:
   case Language::LLVM_IR:
   case Language::RenderScript:
     // We can't do anything with these.
     return;

clang/lib/Frontend/InitPreprocessor.cpp

static void AddObjCXXARCLibstdcxxDefines(const LangOptions &LangOpts,
   }
   Builder.append(Result);
 }
 
 static void InitializeStandardPredefinedMacros(const TargetInfo &TI,
                                                const LangOptions &LangOpts,
                                                const FrontendOptions &FEOpts,
                                                MacroBuilder &Builder) {
+  if (LangOpts.HLSL) {
+    Builder.defineMacro("__hlsl_clang");
+    // HLSL Version
+    Builder.defineMacro("__HLSL_VERSION",
+                        Twine((unsigned)LangOpts.getHLSLVersion()));
+
+    // Shader target information
+    // "enums" for shader stages
+    Builder.defineMacro("__SHADER_STAGE_VERTEX",
+                        Twine((uint32_t)ShaderStage::Vertex));
+    Builder.defineMacro("__SHADER_STAGE_PIXEL",
+                        Twine((uint32_t)ShaderStage::Pixel));
+    Builder.defineMacro("__SHADER_STAGE_GEOMETRY",
+                        Twine((uint32_t)ShaderStage::Geometry));
+    Builder.defineMacro("__SHADER_STAGE_HULL",
+                        Twine((uint32_t)ShaderStage::Hull));
+    Builder.defineMacro("__SHADER_STAGE_DOMAIN",
+                        Twine((uint32_t)ShaderStage::Domain));
+    Builder.defineMacro("__SHADER_STAGE_COMPUTE",
+                        Twine((uint32_t)ShaderStage::Compute));
+    Builder.defineMacro("__SHADER_STAGE_AMPLIFICATION",
+                        Twine((uint32_t)ShaderStage::Amplification));
+    Builder.defineMacro("__SHADER_STAGE_MESH",
+                        Twine((uint32_t)ShaderStage::Mesh));
+    Builder.defineMacro("__SHADER_STAGE_LIBRARY",
+                        Twine((uint32_t)ShaderStage::Library));
+    // The current shader stage itself
+    uint32_t StageInteger = StageInteger =
+        (uint32_t)TI.getTriple().getEnvironment() -
+        (uint32_t)llvm::Triple::Pixel;
+    // TODO: When we add raytracing support we can clean this up
+    if (TI.getTriple().getEnvironment() == llvm::Triple::Mesh)
+      StageInteger = (uint32_t)ShaderStage::Mesh;
+    else if (TI.getTriple().getEnvironment() == llvm::Triple::Amplification)
+      StageInteger = (uint32_t)ShaderStage::Amplification;
+
+    Builder.defineMacro("__SHADER_TARGET_STAGE", Twine(StageInteger));
+    // Add target versions
+    if (TI.getTriple().getOS() == llvm::Triple::ShaderModel) {
+      VersionTuple Version = TI.getTriple().getOSVersion();
+      Builder.defineMacro("__SHADER_TARGET_MAJOR", Twine(Version.getMajor()));
+      unsigned Minor = Version.getMinor() ? *Version.getMinor() : 0;
+      Builder.defineMacro("__SHADER_TARGET_MINOR", Twine(Minor));
+    }
+    return;
+  }
   // C++ [cpp.predefined]p1:
   //   The following macro names shall be defined by the implementation:
 
   //   -- __STDC__
   //      [C++] Whether __STDC__ is predefined and if so, what its value is,
   //      are implementation-defined.
   // (Removed in C++20.)
   if (!LangOpts.MSVCCompat && !LangOpts.TraditionalCPP)

clang/test/Driver/lit.local.cfg

 config.suffixes = ['.c', '.cpp', '.h', '.m', '.mm', '.S', '.s', '.f90', '.F90', '.f95',
-                   '.cu', '.rs', '.cl', '.clcpp', '.hip']
+                   '.cu', '.rs', '.cl', '.clcpp', '.hip', '.hlsl']
 config.substitutions = list(config.substitutions)
 config.substitutions.insert(0,
     ('%clang_cc1',
      """*** Do not use 'clang -cc1' in Driver tests. ***""") )
 
 # Remove harmful environmental variables for clang Driver tests.
 # Some might be useful for other tests so they are only removed here.
 driver_overwrite_env_vars = ['MACOSX_DEPLOYMENT_TARGET',
                              'IPHONEOS_DEPLOYMENT_TARGET',
                              'SDKROOT', 'CCC_OVERRIDE_OPTIONS',
                              'CC_PRINT_OPTIONS', 'CC_PRINT_HEADERS',
                              'CC_LOG_DIAGNOSTICS', 'CC_PRINT_PROC_STAT']
 
 for name in driver_overwrite_env_vars:
   if name in config.environment:
     del config.environment[name]

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

+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-amplification | FileCheck -match-full-lines %s --check-prefixes=CHECK,AMPLIFICATION
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-compute | FileCheck -match-full-lines %s --check-prefixes=CHECK,COMPUTE
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-domain | FileCheck -match-full-lines %s --check-prefixes=CHECK,DOMAIN
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-geometry | FileCheck -match-full-lines %s --check-prefixes=CHECK,GEOMETRY
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-hull | FileCheck -match-full-lines %s --check-prefixes=CHECK,HULL
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-library | FileCheck -match-full-lines %s --check-prefixes=CHECK,LIBRARY
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-mesh | FileCheck -match-full-lines %s --check-prefixes=CHECK,MESH
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-pixel | FileCheck -match-full-lines %s --check-prefixes=CHECK,PIXEL
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -triple dxil-pc-shadermodel6.0-vertex | FileCheck -match-full-lines %s --check-prefixes=CHECK,VERTEX
+
+// CHECK: #define __HLSL_VERSION 2021
+// CHECK: #define __SHADER_STAGE_AMPLIFICATION 14
+// CHECK: #define __SHADER_STAGE_COMPUTE 5
+// CHECK: #define __SHADER_STAGE_DOMAIN 4
+// CHECK: #define __SHADER_STAGE_GEOMETRY 2
+// CHECK: #define __SHADER_STAGE_HULL 3
+// CHECK: #define __SHADER_STAGE_LIBRARY 6
+// CHECK: #define __SHADER_STAGE_MESH 13
+// CHECK: #define __SHADER_STAGE_PIXEL 0
+// CHECK: #define __SHADER_STAGE_VERTEX 1
+
+// AMPLIFICATION: #define __SHADER_TARGET_STAGE 14
+// COMPUTE: #define __SHADER_TARGET_STAGE 5
+// DOMAIN: #define __SHADER_TARGET_STAGE 4
+// GEOMETRY: #define __SHADER_TARGET_STAGE 2
+// HULL: #define __SHADER_TARGET_STAGE 3
+// LIBRARY: #define __SHADER_TARGET_STAGE 6
+// MESH: #define __SHADER_TARGET_STAGE 13
+// PIXEL: #define __SHADER_TARGET_STAGE 0
+// VERTEX: #define __SHADER_TARGET_STAGE 1
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl2015 | FileCheck -match-full-lines %s --check-prefixes=STD2015
+// STD2015: #define __HLSL_VERSION 2015
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl2016 | FileCheck -match-full-lines %s --check-prefixes=STD2016
+// STD2016: #define __HLSL_VERSION 2016
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl2017 | FileCheck -match-full-lines %s --check-prefixes=STD2017
+// STD2017: #define __HLSL_VERSION 2017
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl2018 | FileCheck -match-full-lines %s --check-prefixes=STD2018
+// STD2018: #define __HLSL_VERSION 2018
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl2021 | FileCheck -match-full-lines %s --check-prefixes=STD2021
+// STD2021: #define __HLSL_VERSION 2021
+
+// RUN: %clang_cc1 %s -E -dM -o - -x hlsl -std=hlsl202x | FileCheck -match-full-lines %s --check-prefixes=STD202x
+// STD202x: #define __HLSL_VERSION 2029

clang/test/lit.cfg.py

 
 # testFormat: The test format to use to interpret tests.
 #
 # For now we require '&&' between commands, until they get globally killed and
 # the test runner updated.
 config.test_format = lit.formats.ShTest(not llvm_config.use_lit_shell)
 
 # suffixes: A list of file extensions to treat as test files.
-config.suffixes = ['.c', '.cpp', '.i', '.cppm', '.m', '.mm', '.cu', '.hip',
+config.suffixes = ['.c', '.cpp', '.i', '.cppm', '.m', '.mm', '.cu', '.hip', '.hlsl',
                    '.ll', '.cl', '.clcpp', '.s', '.S', '.modulemap', '.test', '.rs', '.ifs', '.rc']
 
 # excludes: A list of directories to exclude from the testsuite. The 'Inputs'
 # subdirectories contain auxiliary inputs for various tests in their parent
 # directories.
 config.excludes = ['Inputs', 'CMakeLists.txt', 'README.txt', 'LICENSE.txt', 'debuginfo-tests']
 
 # test_source_root: The root path where tests are located.

llvm/lib/Support/Triple.cpp

case MacOSX:
     // macOS 10.16 is canonicalized to macOS 11.
     if (Version == VersionTuple(10, 16))
       return VersionTuple(11, 0);
     LLVM_FALLTHROUGH;
   default:
     return Version;
   }
 }
+
+// HLSL triple environment orders are relied on in the front end
+static_assert(Triple::Vertex - Triple::Pixel == 1,
+              "incorrect HLSL stage order");
+static_assert(Triple::Geometry - Triple::Pixel == 2,
+              "incorrect HLSL stage order");
+static_assert(Triple::Hull - Triple::Pixel == 3,
+              "incorrect HLSL stage order");
+static_assert(Triple::Domain - Triple::Pixel == 4,
+              "incorrect HLSL stage order");
+static_assert(Triple::Compute - Triple::Pixel == 5,
+              "incorrect HLSL stage order");
+static_assert(Triple::Library - Triple::Pixel == 6,
+              "incorrect HLSL stage order");