Incorporate PR feedback

 - Delete call to report_fatal_error and return std::nullopt. As a result
   appropriate unsupported SM version diagnostic is reported.
 - Add the requirement of SubArch to be set for a DXIL Triple to be deemed legal.
 - Add test to verify invalid profile error.

Author: bharadwajy

clang/lib/Driver/ToolChains/HLSL.cpp

@@ -14,6 +14,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/TargetParser/Triple.h"
+#include <optional>
 #include <string>
 
 using namespace clang::driver;
@@ -37,6 +38,11 @@ bool isLegalShaderModel(Triple &T) {
   if (Version.getSubminor())
     return false;
 
+  // DXIL Version should be set as SubArch
+  if (T.getSubArch() == Triple::NoSubArch) {
+    return false;
+  }
+
   auto Kind = T.getEnvironment();
 
   switch (Kind) {
@@ -136,9 +142,8 @@ std::optional<std::string> tryParseProfile(StringRef Profile) {
     break;
   }
   if (SubArch == llvm::Triple::NoSubArch) {
-    report_fatal_error(
-        "No DXIL version found for specified Shader Model version",
-        /*gen_crash_diag*/ false);
+    // No DXIL Version corresponding to specified Shader Model version found
+    return std::nullopt;
   }
   T.setArch(Triple::ArchType::dxil, SubArch);
   T.setOSName(Triple::getOSTypeName(Triple::OSType::ShaderModel).str() +

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

@@ -39,6 +39,9 @@
 // Invaliddxil target with no version number
 // RUN: not %clang -target dxil--shadermodel6.2-msvc %s -S -o /dev/null 2>&1 | FileCheck --check-prefix=CHECK-BAD-TARGET %s
 
+// Invalid target profile
+// RUN: not %clang_dxc  -Tlib_6_9 -fcgl -Fo - %s 2>&1 | FileCheck %s --check-prefix=CHECK-INVALID-PROFILE
+
 // Non-dxil targets
 //
 // RUN: not %clang -target x86_64-unknown-unknown %s -S -o /dev/null 2>&1 | FileCheck --check-prefix=CHECK-BAD-TARGET %s
@@ -52,6 +55,7 @@
 // CHECK-BAD-ENV: error: shader stage '{{.*}}' in target '{{.*}}' is invalid for HLSL code generation
 // CHECK-BAD-ENV-DRV: error: version '{{.*}}' in target triple '{{.*}}' is invalid
 // CHECK-BAD-TARGET: error: HLSL code generation is unsupported for target '{{.*}}'
+// CHECK-INVALID-PROFILE: error: invalid profile : {{.*}}
 
 [shader("pixel")]
 void main() {}