writer/msl: Handle private and workgroup variables

Add a transform that pushes these into the entry point and then passes
them by pointer to any functions that need them.

Since WGSL does not allow non-function storage class at
function-scope, add a DisableValidation attribute to bypass this
check.

Fixed: tint/726
Change-Id: Ic1f4cd691a54c19e77a60e8ba178508e4249bfd9
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/51962
Kokoro: Kokoro <noreply+kokoro@google.com>
Commit-Queue: James Price <jrprice@google.com>
Auto-Submit: James Price <jrprice@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>

test/types/module_scope_declarations.wgsl.expected.msl

@@ -1 +0,0 @@
-SKIP: TINT_UNIMPLEMENTED crbug.com/tint/726: module-scope private and workgroup variables not yet implemented

test/types/module_scope_let.wgsl

@@ -0,0 +1,17 @@
+struct S {
+};
+
+let bool_let : bool = bool();
+let i32_let : i32 = i32();
+let u32_let : u32 = u32();
+let f32_let : f32 = f32();
+let v2i32_let : vec2<i32> = vec2<i32>();
+let v3u32_let : vec3<u32> = vec3<u32>();
+let v4f32_let : vec4<f32> = vec4<f32>();
+let m3x4_let : mat3x4<f32> = mat3x4<f32>();
+let arr_let : array<f32, 4> = array<f32, 4>();
+let struct_let : S = S();
+
+[[stage(compute)]]
+fn main() {
+}

test/types/module_scope_let.wgsl.expected.msl

@@ -0,0 +1,20 @@
+#include <metal_stdlib>
+
+using namespace metal;
+struct S {
+};
+
+constant bool bool_let = bool();
+constant int i32_let = int();
+constant uint u32_let = uint();
+constant float f32_let = float();
+constant int2 v2i32_let = int2();
+constant uint3 v3u32_let = uint3();
+constant float4 v4f32_let = float4();
+constant float3x4 m3x4_let = float3x4();
+constant float arr_let[4] = {};
+constant S struct_let = {};
+kernel void tint_symbol() {
+  return;
+}
+

test/types/module_scope_let.wgsl.expected.spvasm

@@ -0,0 +1,49 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 26
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %main "main"
+               OpExecutionMode %main LocalSize 1 1 1
+               OpName %bool_let "bool_let"
+               OpName %i32_let "i32_let"
+               OpName %u32_let "u32_let"
+               OpName %f32_let "f32_let"
+               OpName %v2i32_let "v2i32_let"
+               OpName %v3u32_let "v3u32_let"
+               OpName %v4f32_let "v4f32_let"
+               OpName %m3x4_let "m3x4_let"
+               OpName %arr_let "arr_let"
+               OpName %S "S"
+               OpName %struct_let "struct_let"
+               OpName %main "main"
+               OpDecorate %_arr_float_uint_4 ArrayStride 4
+       %bool = OpTypeBool
+   %bool_let = OpConstantNull %bool
+        %int = OpTypeInt 32 1
+    %i32_let = OpConstantNull %int
+       %uint = OpTypeInt 32 0
+    %u32_let = OpConstantNull %uint
+      %float = OpTypeFloat 32
+    %f32_let = OpConstantNull %float
+      %v2int = OpTypeVector %int 2
+  %v2i32_let = OpConstantNull %v2int
+     %v3uint = OpTypeVector %uint 3
+  %v3u32_let = OpConstantNull %v3uint
+    %v4float = OpTypeVector %float 4
+  %v4f32_let = OpConstantNull %v4float
+%mat3v4float = OpTypeMatrix %v4float 3
+   %m3x4_let = OpConstantNull %mat3v4float
+     %uint_4 = OpConstant %uint 4
+%_arr_float_uint_4 = OpTypeArray %float %uint_4
+    %arr_let = OpConstantNull %_arr_float_uint_4
+          %S = OpTypeStruct
+ %struct_let = OpConstantNull %S
+       %void = OpTypeVoid
+         %22 = OpTypeFunction %void
+       %main = OpFunction %void None %22
+         %25 = OpLabel
+               OpReturn
+               OpFunctionEnd

test/types/module_scope_let.wgsl.expected.wgsl

@@ -0,0 +1,26 @@
+struct S {
+};
+
+let bool_let : bool = bool();
+
+let i32_let : i32 = i32();
+
+let u32_let : u32 = u32();
+
+let f32_let : f32 = f32();
+
+let v2i32_let : vec2<i32> = vec2<i32>();
+
+let v3u32_let : vec3<u32> = vec3<u32>();
+
+let v4f32_let : vec4<f32> = vec4<f32>();
+
+let m3x4_let : mat3x4<f32> = mat3x4<f32>();
+
+let arr_let : array<f32, 4> = array<f32, 4>();
+
+let struct_let : S = S();
+
+[[stage(compute)]]
+fn main() {
+}

test/types/module_scope_var.wgsl

@@ -0,0 +1,28 @@
+struct S {
+};
+
+var<private> bool_var : bool;
+var<private> i32_var : i32;
+var<private> u32_var : u32;
+var<private> f32_var : f32;
+var<private> v2i32_var : vec2<i32>;
+var<private> v3u32_var : vec3<u32>;
+var<private> v4f32_var : vec4<f32>;
+var<private> m2x3_var : mat2x3<f32>;
+var<private> arr_var : array<f32, 4>;
+var<private> struct_var : S;
+
+[[stage(compute)]]
+fn main() {
+  // Reference the module-scope variables to stop them from being removed.
+  bool_var = bool();
+  i32_var = i32();
+  u32_var = u32();
+  f32_var = f32();
+  v2i32_var = vec2<i32>();
+  v3u32_var = vec3<u32>();
+  v4f32_var = vec4<f32>();
+  m2x3_var = mat2x3<f32>();
+  arr_var = array<f32, 4>();
+  struct_var = S();
+}

test/types/module_scope_var.wgsl.expected.hlsl

@@ -0,0 +1,31 @@
+struct S {
+};
+
+static bool bool_var;
+static int i32_var;
+static uint u32_var;
+static float f32_var;
+static int2 v2i32_var;
+static uint3 v3u32_var;
+static float4 v4f32_var;
+static float2x3 m2x3_var;
+static float arr_var[4];
+static S struct_var;
+
+[numthreads(1, 1, 1)]
+void main() {
+  bool_var = false;
+  i32_var = 0;
+  u32_var = 0u;
+  f32_var = 0.0f;
+  v2i32_var = int2(0, 0);
+  v3u32_var = uint3(0u, 0u, 0u);
+  v4f32_var = float4(0.0f, 0.0f, 0.0f, 0.0f);
+  m2x3_var = float2x3(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
+  const float tint_symbol[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+  arr_var = tint_symbol;
+  const S tint_symbol_1 = {};
+  struct_var = tint_symbol_1;
+  return;
+}
+

test/types/module_scope_var.wgsl.expected.msl

@@ -0,0 +1 @@
+SKIP: crbug.com/tint/814

test/types/module_scope_var.wgsl.expected.spvasm

@@ -0,0 +1,80 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 47
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint GLCompute %main "main"
+               OpExecutionMode %main LocalSize 1 1 1
+               OpName %bool_var "bool_var"
+               OpName %i32_var "i32_var"
+               OpName %u32_var "u32_var"
+               OpName %f32_var "f32_var"
+               OpName %v2i32_var "v2i32_var"
+               OpName %v3u32_var "v3u32_var"
+               OpName %v4f32_var "v4f32_var"
+               OpName %m2x3_var "m2x3_var"
+               OpName %arr_var "arr_var"
+               OpName %S "S"
+               OpName %struct_var "struct_var"
+               OpName %main "main"
+               OpDecorate %_arr_float_uint_4 ArrayStride 4
+       %bool = OpTypeBool
+%_ptr_Private_bool = OpTypePointer Private %bool
+          %4 = OpConstantNull %bool
+   %bool_var = OpVariable %_ptr_Private_bool Private %4
+        %int = OpTypeInt 32 1
+%_ptr_Private_int = OpTypePointer Private %int
+          %8 = OpConstantNull %int
+    %i32_var = OpVariable %_ptr_Private_int Private %8
+       %uint = OpTypeInt 32 0
+%_ptr_Private_uint = OpTypePointer Private %uint
+         %12 = OpConstantNull %uint
+    %u32_var = OpVariable %_ptr_Private_uint Private %12
+      %float = OpTypeFloat 32
+%_ptr_Private_float = OpTypePointer Private %float
+         %16 = OpConstantNull %float
+    %f32_var = OpVariable %_ptr_Private_float Private %16
+      %v2int = OpTypeVector %int 2
+%_ptr_Private_v2int = OpTypePointer Private %v2int
+         %20 = OpConstantNull %v2int
+  %v2i32_var = OpVariable %_ptr_Private_v2int Private %20
+     %v3uint = OpTypeVector %uint 3
+%_ptr_Private_v3uint = OpTypePointer Private %v3uint
+         %24 = OpConstantNull %v3uint
+  %v3u32_var = OpVariable %_ptr_Private_v3uint Private %24
+    %v4float = OpTypeVector %float 4
+%_ptr_Private_v4float = OpTypePointer Private %v4float
+         %28 = OpConstantNull %v4float
+  %v4f32_var = OpVariable %_ptr_Private_v4float Private %28
+    %v3float = OpTypeVector %float 3
+%mat2v3float = OpTypeMatrix %v3float 2
+%_ptr_Private_mat2v3float = OpTypePointer Private %mat2v3float
+         %33 = OpConstantNull %mat2v3float
+   %m2x3_var = OpVariable %_ptr_Private_mat2v3float Private %33
+     %uint_4 = OpConstant %uint 4
+%_arr_float_uint_4 = OpTypeArray %float %uint_4
+%_ptr_Private__arr_float_uint_4 = OpTypePointer Private %_arr_float_uint_4
+         %38 = OpConstantNull %_arr_float_uint_4
+    %arr_var = OpVariable %_ptr_Private__arr_float_uint_4 Private %38
+          %S = OpTypeStruct
+%_ptr_Private_S = OpTypePointer Private %S
+         %42 = OpConstantNull %S
+ %struct_var = OpVariable %_ptr_Private_S Private %42
+       %void = OpTypeVoid
+         %43 = OpTypeFunction %void
+       %main = OpFunction %void None %43
+         %46 = OpLabel
+               OpStore %bool_var %4
+               OpStore %i32_var %8
+               OpStore %u32_var %12
+               OpStore %f32_var %16
+               OpStore %v2i32_var %20
+               OpStore %v3u32_var %24
+               OpStore %v4f32_var %28
+               OpStore %m2x3_var %33
+               OpStore %arr_var %38
+               OpStore %struct_var %42
+               OpReturn
+               OpFunctionEnd

test/types/module_scope_var.wgsl.expected.wgsl

@@ -0,0 +1,36 @@
+struct S {
+};
+
+var<private> bool_var : bool;
+
+var<private> i32_var : i32;
+
+var<private> u32_var : u32;
+
+var<private> f32_var : f32;
+
+var<private> v2i32_var : vec2<i32>;
+
+var<private> v3u32_var : vec3<u32>;
+
+var<private> v4f32_var : vec4<f32>;
+
+var<private> m2x3_var : mat2x3<f32>;
+
+var<private> arr_var : array<f32, 4>;
+
+var<private> struct_var : S;
+
+[[stage(compute)]]
+fn main() {
+  bool_var = bool();
+  i32_var = i32();
+  u32_var = u32();
+  f32_var = f32();
+  v2i32_var = vec2<i32>();
+  v3u32_var = vec3<u32>();
+  v4f32_var = vec4<f32>();
+  m2x3_var = mat2x3<f32>();
+  arr_var = array<f32, 4>();
+  struct_var = S();
+}

test/types/module_scope_var_initializers.wgsl

@@ -2,26 +2,27 @@ struct S {
 };
 
 var<private> bool_var : bool = bool();
-let bool_let : bool = bool();
 var<private> i32_var : i32 = i32();
-let i32_let : i32 = i32();
 var<private> u32_var : u32 = u32();
-let u32_let : u32 = u32();
 var<private> f32_var : f32 = f32();
-let f32_let : f32 = f32();
 var<private> v2i32_var : vec2<i32> = vec2<i32>();
-let v2i32_let : vec2<i32> = vec2<i32>();
 var<private> v3u32_var : vec3<u32> = vec3<u32>();
-let v3u32_let : vec3<u32> = vec3<u32>();
 var<private> v4f32_var : vec4<f32> = vec4<f32>();
-let v4f32_let : vec4<f32> = vec4<f32>();
 var<private> m2x3_var : mat2x3<f32> = mat2x3<f32>();
-let m3x4_let : mat3x4<f32> = mat3x4<f32>();
 var<private> arr_var : array<f32, 4> = array<f32, 4>();
-let arr_let : array<f32, 4> = array<f32, 4>();
 var<private> struct_var : S = S();
-let struct_let : S = S();
 
 [[stage(compute)]]
 fn main() {
+  // Reference the module-scope variables to stop them from being removed.
+  bool_var = bool();
+  i32_var = i32();
+  u32_var = u32();
+  f32_var = f32();
+  v2i32_var = vec2<i32>();
+  v3u32_var = vec3<u32>();
+  v4f32_var = vec4<f32>();
+  m2x3_var = mat2x3<f32>();
+  arr_var = array<f32, 4>();
+  struct_var = S();
 }

test/types/module_scope_var_initializers.wgsl.expected.hlsl

@@ -0,0 +1,31 @@
+struct S {
+};
+
+static bool bool_var = false;
+static int i32_var = 0;
+static uint u32_var = 0u;
+static float f32_var = 0.0f;
+static int2 v2i32_var = int2(0, 0);
+static uint3 v3u32_var = uint3(0u, 0u, 0u);
+static float4 v4f32_var = float4(0.0f, 0.0f, 0.0f, 0.0f);
+static float2x3 m2x3_var = float2x3(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
+static float arr_var[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+static S struct_var = {};
+
+[numthreads(1, 1, 1)]
+void main() {
+  bool_var = false;
+  i32_var = 0;
+  u32_var = 0u;
+  f32_var = 0.0f;
+  v2i32_var = int2(0, 0);
+  v3u32_var = uint3(0u, 0u, 0u);
+  v4f32_var = float4(0.0f, 0.0f, 0.0f, 0.0f);
+  m2x3_var = float2x3(0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
+  const float tint_symbol[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+  arr_var = tint_symbol;
+  const S tint_symbol_1 = {};
+  struct_var = tint_symbol_1;
+  return;
+}
+

test/types/module_scope_var_initializers.wgsl.expected.msl

@@ -0,0 +1 @@
+SKIP: crbug.com/tint/814

test/types/module_scope_var_initializers.wgsl.expected.spvasm

@@ -1,82 +1,80 @@
 ; SPIR-V
 ; Version: 1.3
 ; Generator: Google Tint Compiler; 0
-; Bound: 49
+; Bound: 47
 ; Schema: 0
                OpCapability Shader
                OpMemoryModel Logical GLSL450
                OpEntryPoint GLCompute %main "main"
                OpExecutionMode %main LocalSize 1 1 1
                OpName %bool_var "bool_var"
-               OpName %bool_let "bool_let"
                OpName %i32_var "i32_var"
-               OpName %i32_let "i32_let"
                OpName %u32_var "u32_var"
-               OpName %u32_let "u32_let"
                OpName %f32_var "f32_var"
-               OpName %f32_let "f32_let"
                OpName %v2i32_var "v2i32_var"
-               OpName %v2i32_let "v2i32_let"
                OpName %v3u32_var "v3u32_var"
-               OpName %v3u32_let "v3u32_let"
                OpName %v4f32_var "v4f32_var"
-               OpName %v4f32_let "v4f32_let"
                OpName %m2x3_var "m2x3_var"
-               OpName %m3x4_let "m3x4_let"
                OpName %arr_var "arr_var"
-               OpName %arr_let "arr_let"
                OpName %S "S"
                OpName %struct_var "struct_var"
-               OpName %struct_let "struct_let"
                OpName %main "main"
                OpDecorate %_arr_float_uint_4 ArrayStride 4
        %bool = OpTypeBool
-   %bool_let = OpConstantNull %bool
+          %2 = OpConstantNull %bool
 %_ptr_Private_bool = OpTypePointer Private %bool
-   %bool_var = OpVariable %_ptr_Private_bool Private %bool_let
+   %bool_var = OpVariable %_ptr_Private_bool Private %2
         %int = OpTypeInt 32 1
-    %i32_let = OpConstantNull %int
+          %6 = OpConstantNull %int
 %_ptr_Private_int = OpTypePointer Private %int
-    %i32_var = OpVariable %_ptr_Private_int Private %i32_let
+    %i32_var = OpVariable %_ptr_Private_int Private %6
        %uint = OpTypeInt 32 0
-    %u32_let = OpConstantNull %uint
+         %10 = OpConstantNull %uint
 %_ptr_Private_uint = OpTypePointer Private %uint
-    %u32_var = OpVariable %_ptr_Private_uint Private %u32_let
+    %u32_var = OpVariable %_ptr_Private_uint Private %10
       %float = OpTypeFloat 32
-    %f32_let = OpConstantNull %float
+         %14 = OpConstantNull %float
 %_ptr_Private_float = OpTypePointer Private %float
-    %f32_var = OpVariable %_ptr_Private_float Private %f32_let
+    %f32_var = OpVariable %_ptr_Private_float Private %14
       %v2int = OpTypeVector %int 2
-  %v2i32_let = OpConstantNull %v2int
+         %18 = OpConstantNull %v2int
 %_ptr_Private_v2int = OpTypePointer Private %v2int
-  %v2i32_var = OpVariable %_ptr_Private_v2int Private %v2i32_let
+  %v2i32_var = OpVariable %_ptr_Private_v2int Private %18
      %v3uint = OpTypeVector %uint 3
-  %v3u32_let = OpConstantNull %v3uint
+         %22 = OpConstantNull %v3uint
 %_ptr_Private_v3uint = OpTypePointer Private %v3uint
-  %v3u32_var = OpVariable %_ptr_Private_v3uint Private %v3u32_let
+  %v3u32_var = OpVariable %_ptr_Private_v3uint Private %22
     %v4float = OpTypeVector %float 4
-  %v4f32_let = OpConstantNull %v4float
+         %26 = OpConstantNull %v4float
 %_ptr_Private_v4float = OpTypePointer Private %v4float
-  %v4f32_var = OpVariable %_ptr_Private_v4float Private %v4f32_let
+  %v4f32_var = OpVariable %_ptr_Private_v4float Private %26
     %v3float = OpTypeVector %float 3
 %mat2v3float = OpTypeMatrix %v3float 2
          %31 = OpConstantNull %mat2v3float
 %_ptr_Private_mat2v3float = OpTypePointer Private %mat2v3float
    %m2x3_var = OpVariable %_ptr_Private_mat2v3float Private %31
-%mat3v4float = OpTypeMatrix %v4float 3
-   %m3x4_let = OpConstantNull %mat3v4float
      %uint_4 = OpConstant %uint 4
 %_arr_float_uint_4 = OpTypeArray %float %uint_4
-    %arr_let = OpConstantNull %_arr_float_uint_4
+         %36 = OpConstantNull %_arr_float_uint_4
 %_ptr_Private__arr_float_uint_4 = OpTypePointer Private %_arr_float_uint_4
-    %arr_var = OpVariable %_ptr_Private__arr_float_uint_4 Private %arr_let
+    %arr_var = OpVariable %_ptr_Private__arr_float_uint_4 Private %36
           %S = OpTypeStruct
- %struct_let = OpConstantNull %S
+         %40 = OpConstantNull %S
 %_ptr_Private_S = OpTypePointer Private %S
- %struct_var = OpVariable %_ptr_Private_S Private %struct_let
+ %struct_var = OpVariable %_ptr_Private_S Private %40
        %void = OpTypeVoid
-         %45 = OpTypeFunction %void
-       %main = OpFunction %void None %45
-         %48 = OpLabel
+         %43 = OpTypeFunction %void
+       %main = OpFunction %void None %43
+         %46 = OpLabel
+               OpStore %bool_var %2
+               OpStore %i32_var %6
+               OpStore %u32_var %10
+               OpStore %f32_var %14
+               OpStore %v2i32_var %18
+               OpStore %v3u32_var %22
+               OpStore %v4f32_var %26
+               OpStore %m2x3_var %31
+               OpStore %arr_var %36
+               OpStore %struct_var %40
                OpReturn
                OpFunctionEnd

test/types/module_scope_var_initializers.wgsl.expected.wgsl

@@ -3,44 +3,34 @@ struct S {
 
 var<private> bool_var : bool = bool();
 
-let bool_let : bool = bool();
-
 var<private> i32_var : i32 = i32();
 
-let i32_let : i32 = i32();
-
 var<private> u32_var : u32 = u32();
 
-let u32_let : u32 = u32();
-
 var<private> f32_var : f32 = f32();
 
-let f32_let : f32 = f32();
-
 var<private> v2i32_var : vec2<i32> = vec2<i32>();
 
-let v2i32_let : vec2<i32> = vec2<i32>();
-
 var<private> v3u32_var : vec3<u32> = vec3<u32>();
 
-let v3u32_let : vec3<u32> = vec3<u32>();
-
 var<private> v4f32_var : vec4<f32> = vec4<f32>();
 
-let v4f32_let : vec4<f32> = vec4<f32>();
-
 var<private> m2x3_var : mat2x3<f32> = mat2x3<f32>();
 
-let m3x4_let : mat3x4<f32> = mat3x4<f32>();
-
 var<private> arr_var : array<f32, 4> = array<f32, 4>();
 
-let arr_let : array<f32, 4> = array<f32, 4>();
-
 var<private> struct_var : S = S();
 
-let struct_let : S = S();
-
 [[stage(compute)]]
 fn main() {
+  bool_var = bool();
+  i32_var = i32();
+  u32_var = u32();
+  f32_var = f32();
+  v2i32_var = vec2<i32>();
+  v3u32_var = vec3<u32>();
+  v4f32_var = vec4<f32>();
+  m2x3_var = mat2x3<f32>();
+  arr_var = array<f32, 4>();
+  struct_var = S();
 }