tint: Deprecated module-scope 'let' for 'const'

Enable the parsing of 'const'.
Warn on use of module-scope 'let', and automatically replace with 'const'.

Fixed: tint:1580
Change-Id: I214aabca80686dc6b60ae21a7a57fbfb4898ea83
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/93786
Commit-Queue: Ben Clayton <bclayton@google.com>
Reviewed-by: Dan Sinclair <dsinclair@chromium.org>
Kokoro: Kokoro <noreply+kokoro@google.com>

test/tint/const/global/global.wgsl

@@ -0,0 +1,27 @@
+type MyArray = array<f32, 10>;
+
+// Global consts
+const c1 = 1;
+const c2 = 1u;
+const c3 = 1.0;
+
+const c4 = vec3<i32>(1, 1, 1);
+const c5 = vec3<u32>(1u, 1u, 1u);
+const c6 = vec3<f32>(1.0, 1.0, 1.0);
+
+const c7 = mat3x3<f32>(vec3<f32>(1.0, 1.0, 1.0), vec3<f32>(1.0, 1.0, 1.0), vec3<f32>(1.0, 1.0, 1.0));
+
+const c9 = MyArray();
+
+@fragment
+fn main() -> @location(0) vec4<f32> {
+    var v1 = c1;
+    var v2 = c2;
+    var v3 = c3;
+    var v4 = c4;
+    var v5 = c5;
+    var v6 = c6;
+    var v7 = c7;
+    var v9 = c9;
+    return vec4<f32>(0.0,0.0,0.0,0.0);
+}

test/tint/const/global/global.wgsl.expected.glsl

@@ -0,0 +1,21 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) out vec4 value;
+vec4 tint_symbol() {
+  int v1 = 1;
+  uint v2 = 1u;
+  float v3 = 1.0f;
+  ivec3 v4 = ivec3(1);
+  uvec3 v5 = uvec3(1u);
+  vec3 v6 = vec3(1.0f);
+  mat3 v7 = mat3(vec3(1.0f), vec3(1.0f), vec3(1.0f));
+  float v9[10] = float[10](0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
+  return vec4(0.0f);
+}
+
+void main() {
+  vec4 inner_result = tint_symbol();
+  value = inner_result;
+  return;
+}

test/tint/const/global/global.wgsl.expected.hlsl

@@ -0,0 +1,22 @@
+struct tint_symbol {
+  float4 value : SV_Target0;
+};
+
+float4 main_inner() {
+  int v1 = 1;
+  uint v2 = 1u;
+  float v3 = 1.0f;
+  int3 v4 = (1).xxx;
+  uint3 v5 = (1u).xxx;
+  float3 v6 = (1.0f).xxx;
+  float3x3 v7 = float3x3((1.0f).xxx, (1.0f).xxx, (1.0f).xxx);
+  float v9[10] = (float[10])0;
+  return (0.0f).xxxx;
+}
+
+tint_symbol main() {
+  const float4 inner_result = main_inner();
+  tint_symbol wrapper_result = (tint_symbol)0;
+  wrapper_result.value = inner_result;
+  return wrapper_result;
+}

test/tint/const/global/global.wgsl.expected.msl

@@ -0,0 +1,39 @@
+#include <metal_stdlib>
+
+using namespace metal;
+
+template<typename T, size_t N>
+struct tint_array {
+    const constant T& operator[](size_t i) const constant { return elements[i]; }
+    device T& operator[](size_t i) device { return elements[i]; }
+    const device T& operator[](size_t i) const device { return elements[i]; }
+    thread T& operator[](size_t i) thread { return elements[i]; }
+    const thread T& operator[](size_t i) const thread { return elements[i]; }
+    threadgroup T& operator[](size_t i) threadgroup { return elements[i]; }
+    const threadgroup T& operator[](size_t i) const threadgroup { return elements[i]; }
+    T elements[N];
+};
+
+struct tint_symbol_1 {
+  float4 value [[color(0)]];
+};
+
+float4 tint_symbol_inner() {
+  int v1 = 1;
+  uint v2 = 1u;
+  float v3 = 1.0f;
+  int3 v4 = int3(1);
+  uint3 v5 = uint3(1u);
+  float3 v6 = float3(1.0f);
+  float3x3 v7 = float3x3(float3(1.0f), float3(1.0f), float3(1.0f));
+  tint_array<float, 10> v9 = tint_array<float, 10>{};
+  return float4(0.0f);
+}
+
+fragment tint_symbol_1 tint_symbol() {
+  float4 const inner_result = tint_symbol_inner();
+  tint_symbol_1 wrapper_result = {};
+  wrapper_result.value = inner_result;
+  return wrapper_result;
+}
+

test/tint/const/global/global.wgsl.expected.spvasm

@@ -0,0 +1,87 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 53
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %value
+               OpExecutionMode %main OriginUpperLeft
+               OpName %value "value"
+               OpName %main_inner "main_inner"
+               OpName %v1 "v1"
+               OpName %v2 "v2"
+               OpName %v3 "v3"
+               OpName %v4 "v4"
+               OpName %v5 "v5"
+               OpName %v6 "v6"
+               OpName %v7 "v7"
+               OpName %v9 "v9"
+               OpName %main "main"
+               OpDecorate %value Location 0
+               OpDecorate %_arr_float_uint_10 ArrayStride 4
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+          %5 = OpConstantNull %v4float
+      %value = OpVariable %_ptr_Output_v4float Output %5
+          %6 = OpTypeFunction %v4float
+        %int = OpTypeInt 32 1
+      %int_1 = OpConstant %int 1
+%_ptr_Function_int = OpTypePointer Function %int
+         %13 = OpConstantNull %int
+       %uint = OpTypeInt 32 0
+     %uint_1 = OpConstant %uint 1
+%_ptr_Function_uint = OpTypePointer Function %uint
+         %18 = OpConstantNull %uint
+    %float_1 = OpConstant %float 1
+%_ptr_Function_float = OpTypePointer Function %float
+         %22 = OpConstantNull %float
+      %v3int = OpTypeVector %int 3
+         %24 = OpConstantComposite %v3int %int_1 %int_1 %int_1
+%_ptr_Function_v3int = OpTypePointer Function %v3int
+         %27 = OpConstantNull %v3int
+     %v3uint = OpTypeVector %uint 3
+         %29 = OpConstantComposite %v3uint %uint_1 %uint_1 %uint_1
+%_ptr_Function_v3uint = OpTypePointer Function %v3uint
+         %32 = OpConstantNull %v3uint
+    %v3float = OpTypeVector %float 3
+         %34 = OpConstantComposite %v3float %float_1 %float_1 %float_1
+%_ptr_Function_v3float = OpTypePointer Function %v3float
+         %37 = OpConstantNull %v3float
+%mat3v3float = OpTypeMatrix %v3float 3
+         %39 = OpConstantComposite %mat3v3float %34 %34 %34
+%_ptr_Function_mat3v3float = OpTypePointer Function %mat3v3float
+         %42 = OpConstantNull %mat3v3float
+    %uint_10 = OpConstant %uint 10
+%_arr_float_uint_10 = OpTypeArray %float %uint_10
+         %45 = OpConstantNull %_arr_float_uint_10
+%_ptr_Function__arr_float_uint_10 = OpTypePointer Function %_arr_float_uint_10
+       %void = OpTypeVoid
+         %48 = OpTypeFunction %void
+ %main_inner = OpFunction %v4float None %6
+          %8 = OpLabel
+         %v1 = OpVariable %_ptr_Function_int Function %13
+         %v2 = OpVariable %_ptr_Function_uint Function %18
+         %v3 = OpVariable %_ptr_Function_float Function %22
+         %v4 = OpVariable %_ptr_Function_v3int Function %27
+         %v5 = OpVariable %_ptr_Function_v3uint Function %32
+         %v6 = OpVariable %_ptr_Function_v3float Function %37
+         %v7 = OpVariable %_ptr_Function_mat3v3float Function %42
+         %v9 = OpVariable %_ptr_Function__arr_float_uint_10 Function %45
+               OpStore %v1 %int_1
+               OpStore %v2 %uint_1
+               OpStore %v3 %float_1
+               OpStore %v4 %24
+               OpStore %v5 %29
+               OpStore %v6 %34
+               OpStore %v7 %39
+               OpStore %v9 %45
+               OpReturnValue %5
+               OpFunctionEnd
+       %main = OpFunction %void None %48
+         %51 = OpLabel
+         %52 = OpFunctionCall %v4float %main_inner
+               OpStore %value %52
+               OpReturn
+               OpFunctionEnd

test/tint/const/global/global.wgsl.expected.wgsl

@@ -0,0 +1,30 @@
+type MyArray = array<f32, 10>;
+
+const c1 = 1;
+
+const c2 = 1u;
+
+const c3 = 1.0;
+
+const c4 = vec3<i32>(1, 1, 1);
+
+const c5 = vec3<u32>(1u, 1u, 1u);
+
+const c6 = vec3<f32>(1.0, 1.0, 1.0);
+
+const c7 = mat3x3<f32>(vec3<f32>(1.0, 1.0, 1.0), vec3<f32>(1.0, 1.0, 1.0), vec3<f32>(1.0, 1.0, 1.0));
+
+const c9 = MyArray();
+
+@fragment
+fn main() -> @location(0) vec4<f32> {
+  var v1 = c1;
+  var v2 = c2;
+  var v3 = c3;
+  var v4 = c4;
+  var v5 = c5;
+  var v6 = c6;
+  var v7 = c7;
+  var v9 = c9;
+  return vec4<f32>(0.0, 0.0, 0.0, 0.0);
+}

test/tint/const/inferred/function.wgsl

@@ -0,0 +1,21 @@
+type MyArray = array<f32, 10>;
+
+// Function-scope consts
+fn const_decls() {
+    const v1 = 1;
+    const v2 = 1u;
+    const v3 = 1.0;
+
+    const v4 = vec3<i32>(1, 1, 1);
+    const v5 = vec3<u32>(1u, 1u, 1u);
+    const v6 = vec3<f32>(1.0, 1.0, 1.0);
+
+    const v7 = mat3x3<f32>(v6, v6, v6);
+
+    const v8 = MyArray();
+}
+
+@fragment
+fn main() -> @location(0) vec4<f32> {
+    return vec4<f32>(0.0,0.0,0.0,0.0);
+}

test/tint/const/inferred/function.wgsl.expected.glsl

@@ -0,0 +1,13 @@
+#version 310 es
+precision mediump float;
+
+layout(location = 0) out vec4 value;
+vec4 tint_symbol() {
+  return vec4(0.0f);
+}
+
+void main() {
+  vec4 inner_result = tint_symbol();
+  value = inner_result;
+  return;
+}

test/tint/const/inferred/function.wgsl.expected.hlsl

@@ -0,0 +1,17 @@
+void const_decls() {
+}
+
+struct tint_symbol {
+  float4 value : SV_Target0;
+};
+
+float4 main_inner() {
+  return (0.0f).xxxx;
+}
+
+tint_symbol main() {
+  const float4 inner_result = main_inner();
+  tint_symbol wrapper_result = (tint_symbol)0;
+  wrapper_result.value = inner_result;
+  return wrapper_result;
+}

test/tint/const/inferred/function.wgsl.expected.msl

@@ -0,0 +1,21 @@
+#include <metal_stdlib>
+
+using namespace metal;
+void const_decls() {
+}
+
+struct tint_symbol_1 {
+  float4 value [[color(0)]];
+};
+
+float4 tint_symbol_inner() {
+  return float4(0.0f);
+}
+
+fragment tint_symbol_1 tint_symbol() {
+  float4 const inner_result = tint_symbol_inner();
+  tint_symbol_1 wrapper_result = {};
+  wrapper_result.value = inner_result;
+  return wrapper_result;
+}
+

test/tint/const/inferred/function.wgsl.expected.spvasm

@@ -0,0 +1,36 @@
+; SPIR-V
+; Version: 1.3
+; Generator: Google Tint Compiler; 0
+; Bound: 16
+; Schema: 0
+               OpCapability Shader
+               OpMemoryModel Logical GLSL450
+               OpEntryPoint Fragment %main "main" %value
+               OpExecutionMode %main OriginUpperLeft
+               OpName %value "value"
+               OpName %const_decls "const_decls"
+               OpName %main_inner "main_inner"
+               OpName %main "main"
+               OpDecorate %value Location 0
+      %float = OpTypeFloat 32
+    %v4float = OpTypeVector %float 4
+%_ptr_Output_v4float = OpTypePointer Output %v4float
+          %5 = OpConstantNull %v4float
+      %value = OpVariable %_ptr_Output_v4float Output %5
+       %void = OpTypeVoid
+          %6 = OpTypeFunction %void
+         %10 = OpTypeFunction %v4float
+%const_decls = OpFunction %void None %6
+          %9 = OpLabel
+               OpReturn
+               OpFunctionEnd
+ %main_inner = OpFunction %v4float None %10
+         %12 = OpLabel
+               OpReturnValue %5
+               OpFunctionEnd
+       %main = OpFunction %void None %6
+         %14 = OpLabel
+         %15 = OpFunctionCall %v4float %main_inner
+               OpStore %value %15
+               OpReturn
+               OpFunctionEnd

test/tint/const/inferred/function.wgsl.expected.wgsl

@@ -0,0 +1,17 @@
+type MyArray = array<f32, 10>;
+
+fn const_decls() {
+  const v1 = 1;
+  const v2 = 1u;
+  const v3 = 1.0;
+  const v4 = vec3<i32>(1, 1, 1);
+  const v5 = vec3<u32>(1u, 1u, 1u);
+  const v6 = vec3<f32>(1.0, 1.0, 1.0);
+  const v7 = mat3x3<f32>(v6, v6, v6);
+  const v8 = MyArray();
+}
+
+@fragment
+fn main() -> @location(0) vec4<f32> {
+  return vec4<f32>(0.0, 0.0, 0.0, 0.0);
+}