wasm-grow-memory-in-trap.js

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// |jit-test| test-also=--wasm-compiler=optimizing; skip-if: !wasmDebuggingEnabled()

load(libdir + "wasm.js");

// Memory can grow during debug events, requiring us to update the HeapReg when

// resuming wasm code. We use an i64 memory with no max to force moving grows.

let g = newGlobal({newCompartment: true});

let dbg = new Debugger(g);

let gw = dbg.addDebuggee(g);

g.eval(`

var b = wasmTextToBinary(\`(module

  (memory (export "mem") i64 1)

  (func (export "test") (result i32)

    (i32.load (i64.const 0)))

)\`);

var m = new WebAssembly.Instance(new WebAssembly.Module(b));

var mem = m.exports.mem;

`);

// Install a debug handler that will moving-grow the memory and write a new sentinel.

let grown = false;

dbg.onEnterFrame = function (frame) {

  if (frame.type != 'wasmcall') return;

  frame.onStep = function () {

    if (grown) {

      return;

    const completion = gw.executeInGlobal(`

      mem.grow(100n);                     // force a moving grow

      new Uint8Array(mem.buffer)[0] = 99; // write a new value that test() should observe

`);

    if (completion.throw) {

      throw completion.throw.unsafeDereference();

    grown = true;

};

};

var result = g.eval("m.exports.test()");

assertEq(grown, true);

assertEq(result, 99);