// Copyright 2019 the V8 project authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. // No reason to stress-opt this; save some time. // Flags: --no-stress-opt load('test/mjsunit/wasm/wasm-module-builder.js'); // We generate the module bytes once to make this test more efficient, // especially on simulator builds. The bytes contain a sentinel which is later // patched to different constants. This makes the modules distinct and forces // the engine to create different code for them. // This is the sentinel placed in the bytes. It's a 5 byte LEB-encoded integer. const sentinel = wasmSignedLeb(0x12345678); assertEquals(5, sentinel.length); const builder = new WasmModuleBuilder(); builder.addFunction('f', kSig_i_i).addBody([kExprI32Const, ...sentinel]); const module_bytes = builder.toBuffer(); // Checks whether {module_bytes[i .. i+sentinel.length]} matches {sentinel}. const has_sentinel = (i, k = 0) => module_bytes[i + k] == sentinel[k] && (k == sentinel.length - 1 || has_sentinel(i, k + 1)); // Now find the sentinel. const find_sentinel = i => module_bytes.slice(i).findIndex((e, i) => has_sentinel(i)); const sentinel_position = find_sentinel(0); assertTrue(has_sentinel(sentinel_position), 'found sentinel'); assertEquals(-1, find_sentinel(sentinel_position + 1), 'exactly one sentinel'); // Generating {num_modules} modules should not run out of memory, since the code // space needed per module is quite low. const num_modules = 10000; // Keep all generated modules alive. const modules = []; // Reset sentinel section to nops so that shorter LEBs will just be followed by // nops. This resion will be patched in the loop with values of increasing size. module_bytes.set(Array(sentinel.length).fill(_ => kExprNop), sentinel_position); for (let i = 0; i < num_modules; ++i) { if (i % 50 == 0) print(i); module_bytes.set(wasmSignedLeb(i), sentinel_position); modules.push(new WebAssembly.Module(module_bytes)); }