Fix SPIR-V and Metal support for enum types.

SPIR-V previously didn't know what to think when it encountered a Type
with a typeKind of kEnum, and would abort. These are now treated as
32-bit signed integers.

Metal previously emitted the SkSL enum typename, which is meaningless to
Metal since we do not emit the enum itself anywhere. Metal now emits
"int" for an enum-typed variable.

(GLSL already correctly emits "int" for enum types.)

Change-Id: I05975a2a399f9c4a22c00c90be0dccacd99d793b
Bug: skia:11003
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/338856
Auto-Submit: John Stiles <[email protected]>
Reviewed-by: Brian Osman <[email protected]>
Commit-Queue: John Stiles <[email protected]>

Author: johnstiles-google

gn/sksl_tests.gni

@@ -330,6 +330,7 @@ sksl_blend_tests = [
   "$_tests/sksl/blend/BlendDstIn.sksl",
   "$_tests/sksl/blend/BlendDstOut.sksl",
   "$_tests/sksl/blend/BlendDstOver.sksl",
+  "$_tests/sksl/blend/BlendEnum.sksl",
   "$_tests/sksl/blend/BlendExclusion.sksl",
   "$_tests/sksl/blend/BlendHardLight.sksl",
   "$_tests/sksl/blend/BlendHue.sksl",

src/sksl/SkSLMetalCodeGenerator.cpp

@@ -98,6 +98,8 @@ String MetalCodeGenerator::typeName(const Type& type) {
                                   to_string(type.rows());
         case Type::TypeKind::kSampler:
             return "texture2d<float>"; // FIXME - support other texture types;
+        case Type::TypeKind::kEnum:
+            return "int";
         default:
             if (type == *fContext.fHalf_Type) {
                 // FIXME - Currently only supporting floats in MSL to avoid type coercion issues.

src/sksl/SkSLSPIRVCodeGenerator.cpp

@@ -502,6 +502,9 @@ SpvId SPIRVCodeGenerator::getType(const Type& rawType, const MemoryLayout& layou
                     SkASSERT(false);
                 }
                 break;
+            case Type::TypeKind::kEnum:
+                this->writeInstruction(SpvOpTypeInt, result, 32, 1, fConstantBuffer);
+                break;
             case Type::TypeKind::kVector:
                 this->writeInstruction(SpvOpTypeVector, result,
                                        this->getType(type.componentType(), layout),
@@ -2547,7 +2550,7 @@ SpvId SPIRVCodeGenerator::writeBoolLiteral(const BoolLiteral& b) {
 SpvId SPIRVCodeGenerator::writeIntLiteral(const IntLiteral& i) {
     const Type& type = i.type();
     ConstantType constantType;
-    if (type == *fContext.fInt_Type) {
+    if (type == *fContext.fInt_Type || type.typeKind() == Type::TypeKind::kEnum) {
         constantType = ConstantType::kInt;
     } else if (type == *fContext.fUInt_Type) {
         constantType = ConstantType::kUInt;

tests/sksl/blend/BlendEnum.sksl

@@ -0,0 +1,7 @@
+/*#pragma settings Default*/
+
+in half4 src, dst;
+
+void main() {
+    sk_FragColor = blend(SkBlendMode::kModulate, src, dst);
+}