[HLSL] Restrict to supported targets

[beanz]

Summary

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.

[aaron.ballman]

I don't have particular concerns FWIW, but I'm not certain if others have opinions so I'm holding off on accepting for a bit.

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

15

Thoughts on this change?

[beanz]

Adding the FIXME suggested by @aaron.ballman. Thanks!

[jcranmer-intel]

I don't necessarily know clang-specific code to have that valuable an opinion here, but I don't see anything wrong.

[Anastasia]

This makes sense. I believe the same applies to some other languages i.e. OpenCL, as the way clang evolved currently not all targets are compatible with all languages. In the future we might want to generalize this diagnostics to use in other cases too.

clang/include/clang/Basic/DiagnosticDriverKinds.td

 
 def err_drv_target_variant_invalid : Error<
   "unsupported '%0' value '%1'; use 'ios-macabi' instead">;
 
 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"
   "Validator version must be less than or equal to current internal version.">;
 def err_drv_invalid_format_dxil_validator_version : Error<
   "invalid validator version : %0\n"
   "Format of validator version is \"<major>.<minor>\" (ex:\"1.4\").">;
 def err_drv_invalid_empty_dxil_validator_version : Error<

clang/lib/Frontend/CompilerInvocation.cpp

if (!SeedFile.is_open())
           << A->getValue(0);
 
     std::getline(SeedFile, Opts.RandstructSeed);
   }
 
   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;
 }
 
 static bool isStrictlyPreprocessorAction(frontend::ActionKind Action) {
   switch (Action) {
   case frontend::ASTDeclList:
   case frontend::ASTDump:
   case frontend::ASTPrint:

clang/test/CodeGenHLSL/validator_version.hlsl

 // 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}
 
 // NOT_DXIL-NOT:!dx.valver
 
 float bar(float a, float b);
 
 float foo(float a, float b) {
   return bar(a, b);
 }

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

+// 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

 // 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 - -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