[HLSL] Restrict to supported targets

Someday we would like to support HLSL on a wider range of targets, but
today targeting anything other than `dxil` is likly to cause lots of
headaches. This adds an error and tests to validate that the expected
target is `dxil-?-shadermodel`.

We will continue to do a best effort to ensure the code we write makes
it easy to support other targets (like SPIR-V), but this error will
prevent users from hitting frustrating errors for unsupported cases.

Reviewed By: jcranmer-intel, Anastasia

Differential Revision: https://reviews.llvm.org/D132056

Author: llvm-beanz

clang/include/clang/Basic/DiagnosticDriverKinds.td

@@ -666,6 +666,8 @@ def err_drv_invalid_directx_shader_module : Error<
   "invalid profile : %0">;
 def err_drv_dxc_missing_target_profile : Error<
   "target profile option (-T) is missing">;
+def err_drv_hlsl_unsupported_target : Error<
+  "HLSL code generation is unsupported for target '%0'">;
 
 def err_drv_invalid_range_dxil_validator_version : Error<
   "invalid validator version : %0\n"

clang/lib/Frontend/CompilerInvocation.cpp

@@ -4107,6 +4107,14 @@ bool CompilerInvocation::ParseLangArgs(LangOptions &Opts, ArgList &Args,
   if (const Arg *A = Args.getLastArg(OPT_frandomize_layout_seed_EQ))
     Opts.RandstructSeed = A->getValue(0);
 
+  // Validate options for HLSL
+  if (Opts.HLSL) {
+    bool SupportedTarget = T.getArch() == llvm::Triple::dxil &&
+                           T.getOS() == llvm::Triple::ShaderModel;
+    if (!SupportedTarget)
+      Diags.Report(diag::err_drv_hlsl_unsupported_target) << T.str();
+  }
+
   return Diags.getNumErrors() == NumErrorsBefore;
 }
 

clang/test/CodeGenHLSL/validator_version.hlsl

@@ -1,5 +1,7 @@
 // RUN: %clang -cc1 -S -triple dxil-pc-shadermodel6.3-library -S -emit-llvm -xhlsl -validator-version 1.1 -o - %s | FileCheck %s
-// RUN: %clang -cc1 -S -triple spirv32 -S -emit-llvm -xhlsl -validator-version 1.1 -o - %s | FileCheck %s --check-prefix=NOT_DXIL
+
+// FIXME:The following line should work once SPIR-V support for HLSL is added.
+// DISABLED: %clang -cc1 -S -triple spirv32 -S -emit-llvm -xhlsl -validator-version 1.1 -o - %s | FileCheck %s --check-prefix=NOT_DXIL
 
 // CHECK:!dx.valver = !{![[valver:[0-9]+]]}
 // CHECK:![[valver]] = !{i32 1, i32 1}

clang/test/Driver/hlsl-lang-targets.hlsl

@@ -0,0 +1,14 @@
+// RUN: not %clang -target x86_64-unknown-unknown %s 2>&1 | FileCheck %s --check-prefix=X86
+// RUN: not %clang -target dxil-unknown-unknown %s 2>&1 | FileCheck %s --check-prefix=DXIL
+// RUN: not %clang -target x86_64-unknown-shadermodel %s 2>&1 | FileCheck %s --check-prefix=SM
+// RUN: not %clang -target spirv64-unknown-unknown %s 2>&1 | FileCheck %s --check-prefix=SPIRV
+
+
+// A completely unsupported target...
+// X86: error: HLSL code generation is unsupported for target 'x86_64-unknown-unknown'
+
+// Poorly specified targets
+// DXIL: error: HLSL code generation is unsupported for target 'dxil-unknown-unknown'
+// SM: error: HLSL code generation is unsupported for target 'x86_64-unknown-shadermodel'
+
+// FIXME// SPIRV: error: HLSL code generation is unsupported for target 'spirv64-unknown-unknown'

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

@@ -29,20 +29,20 @@
 // PIXEL: #define __SHADER_TARGET_STAGE 0
 // VERTEX: #define __SHADER_TARGET_STAGE 1
 
-// RUN: %clang_cc1 %s -E -dM -o - -std=hlsl2015 | FileCheck -match-full-lines %s --check-prefixes=STD2015
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %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 - -std=hlsl2016 | FileCheck -match-full-lines %s --check-prefixes=STD2016
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %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 - -std=hlsl2017 | FileCheck -match-full-lines %s --check-prefixes=STD2017
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %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 - -std=hlsl2018 | FileCheck -match-full-lines %s --check-prefixes=STD2018
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %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 - -std=hlsl2021 | FileCheck -match-full-lines %s --check-prefixes=STD2021
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %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 - -std=hlsl202x | FileCheck -match-full-lines %s --check-prefixes=STD202x
+// RUN: %clang_cc1 -triple dxil-pc-shadermodel6.0-library %s -E -dM -o - -x hlsl -std=hlsl202x | FileCheck -match-full-lines %s --check-prefixes=STD202x
 // STD202x: #define __HLSL_VERSION 2029