Enable proper testing of const arrays.

This test was generating invalid code in Metal
(http://review.skia.org/408356), but we didn't catch it because the code
wasn't actually being run.

Change-Id: I649034593a566f9e835b1cf7b0702c64952d31ef
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/408641
Auto-Submit: John Stiles <johnstiles@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

resources/sksl/shared/ConstArray.sksl

@@ -1,5 +1,5 @@
-const half test[4] = half[4](1, 2, 3, 4);
+const half test[4] = half[4](0, 1, 0, 1);
 
-void main() {
-    sk_FragColor = half4(test[0], test[1], test[2], test[3]);
+half4 main(float2 xy) {
+    return half4(test[0], test[1], test[2], test[3]);
 }

tests/SkSLTest.cpp

@@ -222,6 +222,7 @@ SKSL_TEST(SkSLCommaMixedTypes,                 "shared/CommaMixedTypes.sksl")
 // The CPU test confirms that we can get it right, even if not all drivers do.
 SKSL_TEST_CPU(SkSLCommaSideEffects,            "shared/CommaSideEffects.sksl")
 SKSL_TEST(SkSLConstantIf,                      "shared/ConstantIf.sksl")
+SKSL_TEST_ES3(SkSLConstArray,                  "shared/ConstArray.sksl")
 SKSL_TEST(SkSLConstVariableComparison,         "shared/ConstVariableComparison.sksl")
 SKSL_TEST(SkSLDeadIfStatement,                 "shared/DeadIfStatement.sksl")
 SKSL_TEST(SkSLDeadStripFunctions,              "shared/DeadStripFunctions.sksl")

tests/sksl/shared/ConstArray.asm.frag

@@ -1,11 +1,12 @@
 OpCapability Shader
 %1 = OpExtInstImport "GLSL.std.450"
 OpMemoryModel Logical GLSL450
-OpEntryPoint Fragment %main "main" %sk_FragColor %sk_Clockwise
-OpExecutionMode %main OriginUpperLeft
+OpEntryPoint Fragment %_entrypoint_v "_entrypoint" %sk_FragColor %sk_Clockwise
+OpExecutionMode %_entrypoint_v OriginUpperLeft
 OpName %sk_FragColor "sk_FragColor"
 OpName %sk_Clockwise "sk_Clockwise"
 OpName %test "test"
+OpName %_entrypoint_v "_entrypoint_v"
 OpName %main "main"
 OpDecorate %sk_FragColor RelaxedPrecision
 OpDecorate %sk_FragColor Location 0
@@ -13,12 +14,12 @@ OpDecorate %sk_FragColor Index 0
 OpDecorate %sk_Clockwise BuiltIn FrontFacing
 OpDecorate %test RelaxedPrecision
 OpDecorate %_arr_float_int_4 ArrayStride 16
-OpDecorate %19 RelaxedPrecision
-OpDecorate %26 RelaxedPrecision
-OpDecorate %29 RelaxedPrecision
-OpDecorate %32 RelaxedPrecision
-OpDecorate %35 RelaxedPrecision
+OpDecorate %17 RelaxedPrecision
+OpDecorate %33 RelaxedPrecision
 OpDecorate %36 RelaxedPrecision
+OpDecorate %39 RelaxedPrecision
+OpDecorate %42 RelaxedPrecision
+OpDecorate %43 RelaxedPrecision
 %float = OpTypeFloat 32
 %v4float = OpTypeVector %float 4
 %_ptr_Output_v4float = OpTypePointer Output %v4float
@@ -31,30 +32,40 @@ OpDecorate %36 RelaxedPrecision
 %_arr_float_int_4 = OpTypeArray %float %int_4
 %_ptr_Private__arr_float_int_4 = OpTypePointer Private %_arr_float_int_4
 %test = OpVariable %_ptr_Private__arr_float_int_4 Private
+%float_0 = OpConstant %float 0
 %float_1 = OpConstant %float 1
-%float_2 = OpConstant %float 2
-%float_3 = OpConstant %float 3
-%float_4 = OpConstant %float 4
 %void = OpTypeVoid
-%21 = OpTypeFunction %void
+%20 = OpTypeFunction %void
+%v2float = OpTypeVector %float 2
+%23 = OpConstantComposite %v2float %float_0 %float_0
+%_ptr_Function_v2float = OpTypePointer Function %v2float
+%27 = OpTypeFunction %v4float %_ptr_Function_v2float
 %int_0 = OpConstant %int 0
 %_ptr_Private_float = OpTypePointer Private %float
 %int_1 = OpConstant %int 1
 %int_2 = OpConstant %int 2
 %int_3 = OpConstant %int 3
-%main = OpFunction %void None %21
-%22 = OpLabel
-%19 = OpCompositeConstruct %_arr_float_int_4 %float_1 %float_2 %float_3 %float_4
-OpStore %test %19
-%24 = OpAccessChain %_ptr_Private_float %test %int_0
-%26 = OpLoad %float %24
-%28 = OpAccessChain %_ptr_Private_float %test %int_1
-%29 = OpLoad %float %28
-%31 = OpAccessChain %_ptr_Private_float %test %int_2
-%32 = OpLoad %float %31
-%34 = OpAccessChain %_ptr_Private_float %test %int_3
-%35 = OpLoad %float %34
-%36 = OpCompositeConstruct %v4float %26 %29 %32 %35
-OpStore %sk_FragColor %36
+%_entrypoint_v = OpFunction %void None %20
+%21 = OpLabel
+%24 = OpVariable %_ptr_Function_v2float Function
+OpStore %24 %23
+%26 = OpFunctionCall %v4float %main %24
+OpStore %sk_FragColor %26
 OpReturn
 OpFunctionEnd
+%main = OpFunction %v4float None %27
+%28 = OpFunctionParameter %_ptr_Function_v2float
+%29 = OpLabel
+%17 = OpCompositeConstruct %_arr_float_int_4 %float_0 %float_1 %float_0 %float_1
+OpStore %test %17
+%31 = OpAccessChain %_ptr_Private_float %test %int_0
+%33 = OpLoad %float %31
+%35 = OpAccessChain %_ptr_Private_float %test %int_1
+%36 = OpLoad %float %35
+%38 = OpAccessChain %_ptr_Private_float %test %int_2
+%39 = OpLoad %float %38
+%41 = OpAccessChain %_ptr_Private_float %test %int_3
+%42 = OpLoad %float %41
+%43 = OpCompositeConstruct %v4float %33 %36 %39 %42
+OpReturnValue %43
+OpFunctionEnd

tests/sksl/shared/ConstArray.glsl

@@ -1,6 +1,6 @@
 
 out vec4 sk_FragColor;
-const float test[4] = float[4](1.0, 2.0, 3.0, 4.0);
-void main() {
-    sk_FragColor = vec4(test[0], test[1], test[2], test[3]);
+const float test[4] = float[4](0.0, 1.0, 0.0, 1.0);
+vec4 main() {
+    return vec4(test[0], test[1], test[2], test[3]);
 }

tests/sksl/shared/ConstArray.metal

@@ -10,7 +10,7 @@ struct Globals {
     const array<float, 4> test;
 };
 fragment Outputs fragmentMain(Inputs _in [[stage_in]], bool _frontFacing [[front_facing]], float4 _fragCoord [[position]]) {
-    Globals _globals{array<float, 4>{1.0, 2.0, 3.0, 4.0}};
+    Globals _globals{array<float, 4>{0.0, 1.0, 0.0, 1.0}};
     (void)_globals;
     Outputs _out;
     (void)_out;