src/webgpu/shader/validation/expression/precedence.spec.ts

export const description = `
Validation tests for operator precedence.
`;

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);

// Bit set for the binary operator groups.
const kMultiplicative = 1 << 0;
const kAdditive = 1 << 1;
const kShift = 1 << 2;
const kRelational = 1 << 3;
const kBinaryAnd = 1 << 4;
const kBinaryXor = 1 << 5;
const kBinaryOr = 1 << 6;
const kLogical = 1 << 7;

// Set of other operators that each operator can precede without any parentheses.
const kCanPrecedeWithoutParens: Record<number, number> = {};
kCanPrecedeWithoutParens[kMultiplicative] = kMultiplicative | kAdditive | kRelational;
kCanPrecedeWithoutParens[kAdditive] = kMultiplicative | kAdditive | kRelational;
kCanPrecedeWithoutParens[kShift] = kRelational | kLogical;
kCanPrecedeWithoutParens[kRelational] = kMultiplicative | kAdditive | kShift | kLogical;
kCanPrecedeWithoutParens[kBinaryAnd] = kBinaryAnd;
kCanPrecedeWithoutParens[kBinaryXor] = kBinaryXor;
kCanPrecedeWithoutParens[kBinaryOr] = kBinaryOr;
kCanPrecedeWithoutParens[kLogical] = kRelational;

// The list of binary operators.
interface BinaryOperatorInfo {
  op: string;
  group: number;
}
const kBinaryOperators: Record<string, BinaryOperatorInfo> = {
  mul: { op: '*', group: kMultiplicative },
  div: { op: '/', group: kMultiplicative },
  mod: { op: '%', group: kMultiplicative },

  add: { op: '+', group: kAdditive },
  sub: { op: '-', group: kAdditive },

  shl: { op: '<<', group: kShift },
  shr: { op: '>>', group: kShift },

  lt: { op: '<', group: kRelational },
  gt: { op: '>', group: kRelational },
  le: { op: '<=', group: kRelational },
  ge: { op: '>=', group: kRelational },
  eq: { op: '==', group: kRelational },
  ne: { op: '!=', group: kRelational },

  bin_and: { op: '&', group: kBinaryAnd },
  bin_xor: { op: '^', group: kBinaryXor },
  bin_or: { op: '|', group: kBinaryOr },

  log_and: { op: '&&', group: kLogical },
  log_or: { op: '||', group: kLogical },
};

g.test('binary_requires_parentheses')
  .desc(
    `
  Validates that certain binary operators require parentheses to bind correctly.
  `
  )
  .params(u =>
    u
      .combine('op1', keysOf(kBinaryOperators))
      .combine('op2', keysOf(kBinaryOperators))
      .filter(p => {
        // Skip expressions that would parse as template lists.
        if (p.op1 === 'lt' && ['gt', 'ge', 'shr'].includes(p.op2)) {
          return false;
        }
        // Only combine logical operators with relational operators.
        if (kBinaryOperators[p.op1].group === kLogical) {
          return kBinaryOperators[p.op2].group === kRelational;
        }
        if (kBinaryOperators[p.op2].group === kLogical) {
          return kBinaryOperators[p.op1].group === kRelational;
        }
        return true;
      })
  )
  .fn(t => {
    const op1 = kBinaryOperators[t.params.op1];
    const op2 = kBinaryOperators[t.params.op2];
    const code = `
var<private> a : ${op1.group === kLogical ? 'bool' : 'u32'};
var<private> b : u32;
var<private> c : ${op2.group === kLogical ? 'bool' : 'u32'};
fn foo() {
  let foo = a ${op1.op} b ${op2.op} c;
}
`;

    const valid = (kCanPrecedeWithoutParens[op1.group] & op2.group) !== 0;
    t.expectCompileResult(valid, code);
  });

g.test('mixed_logical_requires_parentheses')
  .desc(
    `
  Validates that mixed logical operators require parentheses to bind correctly.
  `
  )
  .params(u =>
    u
      .combine('op1', keysOf(kBinaryOperators))
      .combine('op2', keysOf(kBinaryOperators))
      .combine('parens', ['none', 'left', 'right'])
      .filter(p => {
        const group1 = kBinaryOperators[p.op1].group;
        const group2 = kBinaryOperators[p.op2].group;
        return group1 === kLogical && group2 === kLogical;
      })
  )
  .fn(t => {
    const op1 = kBinaryOperators[t.params.op1];
    const op2 = kBinaryOperators[t.params.op2];
    let expr = `a ${op1.op} b ${op2.op} c;`;
    if (t.params.parens === 'left') {
      expr = `(a ${op1.op} b) ${op2.op} c;`;
    } else if (t.params.parens === 'right') {
      expr = `a ${op1.op} (b ${op2.op} c);`;
    }
    const code = `
var<private> a : bool;
var<private> b : bool;
var<private> c : bool;
fn foo() {
  let bar = ${expr};
}
`;
    const valid = t.params.parens !== 'none' || t.params.op1 === t.params.op2;
    t.expectCompileResult(valid, code);
  });

// The list of miscellaneous other test cases.
interface Expression {
  expr: string;
  result: boolean;
}
const kExpressions: Record<string, Expression> = {
  neg_member: { expr: '- str . a', result: true },
  comp_member: { expr: '~ str . a', result: true },
  addr_member: { expr: '& str . a', result: true },
  log_and_member: { expr: 'false && str . b', result: true },
  log_or_member: { expr: 'false || str . b', result: true },
  and_addr: { expr: '      v &  &str .a', result: false },
  and_addr_paren: { expr: 'v & (&str).a', result: true },
  deref_member: { expr: '       * ptr_str  . a', result: false },
  deref_member_paren: { expr: '(* ptr_str) . a', result: true },
  deref_idx: { expr: '       * ptr_vec  [0]', result: false },
  deref_idx_paren: { expr: '(* ptr_vec) [1]', result: true },
};

g.test('other')
  .desc(
    `
    Test that other operator precedence rules are correctly implemented.
    `
  )
  .params(u => u.combine('expr', keysOf(kExpressions)))
  .fn(t => {
    const expr = kExpressions[t.params.expr];
    const wgsl = `
      struct S {
        a: i32,
        b: bool,
      }

      fn main() {
        var v = 42;
        var vec = vec4();
        var str = S(42, false);
        let ptr_vec = &vec;
        let ptr_str = &str;

        let foo = ${expr.expr};
      }
    `;

    t.expectCompileResult(expr.result, wgsl);
  });

const kLHSExpressions = {
  deref_invalid1: { expr: `*p.b`, result: false },
  deref_invalid2: { expr: `*p.a[0]`, result: false },
  deref_valid1: { expr: `(*p).b`, result: true },
  deref_valid2: { expr: `(*p).a[2]`, result: true },
  addr_valid1: { expr: `*&v.b`, result: true },
  addr_valid2: { expr: `(*&v).b`, result: true },
  addr_valid3: { expr: `*&(v.b)`, result: true },
};

g.test('other_lhs')
  .desc('Test precedence of * and [] in LHS')
  .params(u => u.combine('expr', keysOf(kLHSExpressions)))
  .fn(t => {
    const expr = kLHSExpressions[t.params.expr];
    const code = `
    struct S {
      a : array<i32, 4>,
      b : i32,
    }
    fn main() {
      var v : S;
      let p = &v;
      let q = &v.a;

      ${expr.expr} = 1i;
    }`;

    t.expectCompileResult(expr.result, code);
  });