Validate out CullDistance in HLSL, MSL and GLSL.

Only the SPIR-V backend supports the CullDistance builtin. Update the
CanGenerate methods for the other backends to validate out the usage of
CullDistance.

Fixed: 467683480
Change-Id: Ic1b291cd1a7ac92ded5b0bf3fb5dd30a67ca2eb5
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/280615
Commit-Queue: James Price <jrprice@google.com>
Auto-Submit: dan sinclair <dsinclair@chromium.org>
Commit-Queue: dan sinclair <dsinclair@chromium.org>
Reviewed-by: James Price <jrprice@google.com>

Author: dj2

src/tint/lang/glsl/writer/writer.cc

@@ -215,6 +215,9 @@ Result<SuccessType> CanGenerate(const core::ir::Module& ir, const Options& optio
                 if (member->Attributes().builtin == core::BuiltinValue::kClipDistances) {
                     return Failure("clip_distances is not supported by the GLSL backend");
                 }
+                if (member->Attributes().builtin == core::BuiltinValue::kCullDistance) {
+                    return Failure("cull_distance is not supported by the GLSL backend");
+                }
             }
         }
     }

src/tint/lang/hlsl/writer/writer.cc

@@ -166,6 +166,9 @@ Result<SuccessType> CanGenerate(const core::ir::Module& ir, const Options& optio
             options.compiler == Options::Compiler::kFXC) {
             return Failure("barycentric_coord is not supported by the FXC HLSL backend");
         }
+        if (attributes.builtin == core::BuiltinValue::kCullDistance) {
+            return Failure("cull_distance is not supported by the HLSL backend");
+        }
         if (options.truncate_interstage_variables) {
             if (attributes.location >= 30u) {
                 return Failure("too many locations for interstage variable truncation");

src/tint/lang/msl/writer/writer.cc

@@ -80,11 +80,52 @@ Result<SuccessType> CanGenerate(const core::ir::Module& ir, const Options& optio
         }
     }
 
+    // Check for unsupported shader IO builtins.
+    auto check_io_attributes = [&](const core::IOAttributes& attributes) -> Result<SuccessType> {
+        if (attributes.builtin == core::BuiltinValue::kCullDistance) {
+            return Failure("cull_distance is not supported by the MSL backend");
+        }
+        return Success;
+    };
+
     core::ir::Function* ep_func = nullptr;
     for (auto* f : ir.functions) {
         if (!f->IsEntryPoint()) {
             continue;
         }
+
+        // Check input attributes.
+        for (auto* param : f->Params()) {
+            if (auto* str = param->Type()->As<core::type::Struct>()) {
+                for (auto* member : str->Members()) {
+                    auto res = check_io_attributes(member->Attributes());
+                    if (res != Success) {
+                        return res;
+                    }
+                }
+            } else {
+                auto res = check_io_attributes(param->Attributes());
+                if (res != Success) {
+                    return res;
+                }
+            }
+        }
+
+        // Check output attributes.
+        if (auto* str = f->ReturnType()->As<core::type::Struct>()) {
+            for (auto* member : str->Members()) {
+                auto res = check_io_attributes(member->Attributes());
+                if (res != Success) {
+                    return res;
+                }
+            }
+        } else {
+            auto res = check_io_attributes(f->ReturnAttributes());
+            if (res != Success) {
+                return res;
+            }
+        }
+
         if (ir.NameOf(f).NameView() == options.entry_point_name) {
             ep_func = f;
             break;