[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

1 files changed, 8 insertions, 0 deletions

diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
index 574514b..9ac522a 100644
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/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;
 }