Add validation tests for pointer_composite_access (#3298)

As per: gpuweb/gpuweb#4311

src/webgpu/listing_meta.json

@@ -1830,6 +1830,8 @@
   "webgpu:shader,validation,expression,call,builtin,unpack4xU8:must_use:*": { "subcaseMS": 32.800 },
   "webgpu:shader,validation,expression,call,builtin,unpack4xU8:supported:*": { "subcaseMS": 98.501 },
   "webgpu:shader,validation,expression,call,builtin,unpack4xU8:unsupported:*": { "subcaseMS": 346.801 },
+  "webgpu:shader,validation,extension,pointer_composite_access:deref:*": { "subcaseMS": 0.0 },
+  "webgpu:shader,validation,extension,pointer_composite_access:pointer:*": { "subcaseMS": 0.0 },
   "webgpu:shader,validation,functions,alias_analysis:aliasing_inside_function:*": { "subcaseMS": 1.200 },
   "webgpu:shader,validation,functions,alias_analysis:member_accessors:*": { "subcaseMS": 1.656 },
   "webgpu:shader,validation,functions,alias_analysis:one_pointer_one_module_scope:*": { "subcaseMS": 1.598 },

src/webgpu/shader/validation/extension/pointer_composite_access.spec.ts

@@ -0,0 +1,130 @@
+export const description = `
+Validation tests for pointer_composite_access extension
+`;
+
+import { makeTestGroup } from '../../../../common/framework/test_group.js';
+import { keysOf } from '../../../../common/util/data_tables.js';
+import { ShaderValidationTest } from '../shader_validation_test.js';
+
+export const g = makeTestGroup(ShaderValidationTest);
+
+function makeSource(module: string, init_expr: string, pointer_read_expr: string) {
+  return `
+    ${module}
+    fn f() {
+        var a = ${init_expr};
+        let p = &a;
+        let r = ${pointer_read_expr};
+    }`;
+}
+
+const kCases = {
+  // Via identifier 'a'
+  array_index_access_via_identifier: {
+    module: '',
+    init_expr: 'array<i32, 3>()',
+    via_deref: '(*(&a))[0];',
+    via_pointer: '(&a)[0];',
+  },
+  vector_index_access_via_identifier: {
+    module: '',
+    init_expr: 'vec3<i32>()',
+    via_deref: '(*(&a))[0]',
+    via_pointer: '(&a)[0]',
+  },
+  vector_member_access_via_identifier: {
+    module: '',
+    init_expr: 'vec3<i32>()',
+    via_deref: '(*(&a)).x;',
+    via_pointer: '(&a).x;',
+  },
+  matrix_index_access_via_identifier: {
+    module: '',
+    init_expr: 'mat2x3<f32>()',
+    via_deref: '(*(&a))[0]',
+    via_pointer: '(&a)[0]',
+  },
+  struct_member_access_via_identifier: {
+    module: 'struct S { a : i32, }',
+    init_expr: 'S()',
+    via_deref: '(*(&a)).a;',
+    via_pointer: '(&a).a;',
+  },
+  builtin_struct_modf_via_identifier: {
+    module: '',
+    init_expr: 'modf(1.5)',
+    via_deref: 'vec2((*(&a)).fract, (*(&a)).whole)',
+    via_pointer: 'vec2((&a).fract, (&a).whole)',
+  },
+  builtin_struct_frexp_via_identifier: {
+    module: '',
+    init_expr: 'frexp(1.5)',
+    via_deref: 'vec2((*(&a)).fract, f32((*(&a)).exp))',
+    via_pointer: 'vec2((&a).fract, f32((&a).exp))',
+  },
+
+  // Via pointer 'p'
+  array_index_access_via_pointer: {
+    module: '',
+    init_expr: 'array<i32, 3>()',
+    via_deref: '(*p)[0];',
+    via_pointer: 'p[0];',
+  },
+  vector_index_access_via_pointer: {
+    module: '',
+    init_expr: 'vec3<i32>()',
+    via_deref: '(*p)[0]',
+    via_pointer: 'p[0]',
+  },
+  vector_member_access_via_pointer: {
+    module: '',
+    init_expr: 'vec3<i32>()',
+    via_deref: '(*p).x;',
+    via_pointer: 'p.x;',
+  },
+  matrix_index_access_via_pointer: {
+    module: '',
+    init_expr: 'mat2x3<f32>()',
+    via_deref: '(*p)[0]',
+    via_pointer: 'p[0]',
+  },
+  struct_member_access_via_pointer: {
+    module: 'struct S { a : i32, }',
+    init_expr: 'S()',
+    via_deref: '(*p).a;',
+    via_pointer: 'p.a;',
+  },
+  builtin_struct_modf_via_pointer: {
+    module: '',
+    init_expr: 'modf(1.5)',
+    via_deref: 'vec2((*p).fract, (*p).whole)',
+    via_pointer: 'vec2(p.fract, p.whole)',
+  },
+  builtin_struct_frexp_via_pointer: {
+    module: '',
+    init_expr: 'frexp(1.5)',
+    via_deref: 'vec2((*p).fract, f32((*p).exp))',
+    via_pointer: 'vec2(p.fract, f32(p.exp))',
+  },
+};
+
+g.test('deref')
+  .desc('Baseline test: pointer deref is always valid')
+  .params(u => u.combine('case', keysOf(kCases)))
+  .fn(t => {
+    const curr = kCases[t.params.case];
+    const source = makeSource(curr.module, curr.init_expr, curr.via_deref);
+    t.expectCompileResult(true, source);
+  });
+
+g.test('pointer')
+  .desc(
+    'Tests that direct pointer access is valid if pointer_composite_access is supported, else it should fail'
+  )
+  .params(u => u.combine('case', keysOf(kCases)))
+  .fn(t => {
+    const curr = kCases[t.params.case];
+    const source = makeSource(curr.module, curr.init_expr, curr.via_pointer);
+    const should_pass = t.hasLanguageFeature('pointer_composite_access');
+    t.expectCompileResult(should_pass, source);
+  });