Add HLSL Language Option and Preprocessor

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.

Reviewed By: pete, rnk

Differential Revision: https://reviews.llvm.org/D122087

3 files changed, 74 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index b222119..f8fd3a2 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -2623,6 +2623,9 @@ static void GenerateFrontendArgs(const FrontendOptions &Opts,
     case Language::LLVM_IR:
       Lang = "ir";
       break;
+    case Language::HLSL:
+      Lang = "hlsl";
+      break;
     }
 
     GenerateArg(Args, OPT_x,
@@ -2809,6 +2812,7 @@ static bool ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
                 .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
@@ -3220,6 +3224,9 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
     case Language::HIP:
       LangStd = LangStandard::lang_hip;
       break;
+    case Language::HLSL:
+      LangStd = LangStandard::lang_hlsl2021;
+      break;
     }
   }
 
@@ -3241,6 +3248,8 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   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)
@@ -3257,6 +3266,18 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
     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) {
@@ -3341,6 +3362,9 @@ static bool IsInputCompatibleWithStandard(InputKind IK,
     // 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");
@@ -3373,6 +3397,9 @@ static StringRef GetInputKindName(InputKind IK) {
   case Language::LLVM_IR:
     return "LLVM IR";
 
+  case Language::HLSL:
+    return "HLSL";
+
   case Language::Unknown:
     break;
   }
diff --git a/clang/lib/Frontend/FrontendActions.cpp b/clang/lib/Frontend/FrontendActions.cpp
index 2cd2096..e219be3 100644
--- a/clang/lib/Frontend/FrontendActions.cpp
+++ b/clang/lib/Frontend/FrontendActions.cpp
@@ -1078,6 +1078,7 @@ void PrintPreambleAction::ExecuteAction() {
   case Language::OpenCLCXX:
   case Language::CUDA:
   case Language::HIP:
+  case Language::HLSL:
     break;
 
   case Language::Unknown:
diff --git a/clang/lib/Frontend/InitPreprocessor.cpp b/clang/lib/Frontend/InitPreprocessor.cpp
index 9d7a429..89e9cb0 100644
--- a/clang/lib/Frontend/InitPreprocessor.cpp
+++ b/clang/lib/Frontend/InitPreprocessor.cpp
@@ -371,6 +371,52 @@ 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: