| // Copyright 2016 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. |
| |
| class Binary extends Array { |
| emit_u8(val) { |
| this.push(val); |
| } |
| |
| emit_u16(val) { |
| this.push(val & 0xff); |
| this.push((val >> 8) & 0xff); |
| } |
| |
| emit_u32(val) { |
| this.push(val & 0xff); |
| this.push((val >> 8) & 0xff); |
| this.push((val >> 16) & 0xff); |
| this.push((val >> 24) & 0xff); |
| } |
| |
| emit_varint(val) { |
| while (true) { |
| let v = val & 0xff; |
| val = val >>> 7; |
| if (val == 0) { |
| this.push(v); |
| break; |
| } |
| this.push(v | 0x80); |
| } |
| } |
| |
| emit_bytes(data) { |
| for (let i = 0; i < data.length; i++) { |
| this.push(data[i] & 0xff); |
| } |
| } |
| |
| emit_string(string) { |
| // When testing illegal names, we pass a byte array directly. |
| if (string instanceof Array) { |
| this.emit_varint(string.length); |
| this.emit_bytes(string); |
| return; |
| } |
| |
| // This is the hacky way to convert a JavaScript string to a UTF8 encoded |
| // string only containing single-byte characters. |
| let string_utf8 = unescape(encodeURIComponent(string)); |
| this.emit_varint(string_utf8.length); |
| for (let i = 0; i < string_utf8.length; i++) { |
| this.emit_u8(string_utf8.charCodeAt(i)); |
| } |
| } |
| |
| emit_header() { |
| this.push(kWasmH0, kWasmH1, kWasmH2, kWasmH3, |
| kWasmV0, kWasmV1, kWasmV2, kWasmV3); |
| } |
| |
| emit_section(section_code, content_generator) { |
| // Emit section name. |
| this.emit_string(section_names[section_code]); |
| // Emit the section to a temporary buffer: its full length isn't know yet. |
| let section = new Binary; |
| content_generator(section); |
| // Emit section length. |
| this.emit_varint(section.length); |
| // Copy the temporary buffer. |
| this.push(...section); |
| } |
| } |
| |
| class WasmFunctionBuilder { |
| constructor(name, type_index) { |
| this.name = name; |
| this.type_index = type_index; |
| this.exports = []; |
| } |
| |
| exportAs(name) { |
| this.exports.push(name); |
| return this; |
| } |
| |
| exportFunc() { |
| this.exports.push(this.name); |
| return this; |
| } |
| |
| addBody(body) { |
| this.body = body; |
| return this; |
| } |
| |
| addLocals(locals) { |
| this.locals = locals; |
| return this; |
| } |
| } |
| |
| class WasmModuleBuilder { |
| constructor() { |
| this.types = []; |
| this.imports = []; |
| this.functions = []; |
| this.exports = []; |
| this.table = []; |
| this.segments = []; |
| this.explicit = []; |
| this.pad = null; |
| return this; |
| } |
| |
| addStart(start_index) { |
| this.start_index = start_index; |
| } |
| |
| addMemory(min, max, exp) { |
| this.memory = {min: min, max: max, exp: exp}; |
| return this; |
| } |
| |
| addPadFunctionTable(size) { |
| this.pad = size; |
| return this; |
| } |
| |
| addExplicitSection(bytes) { |
| this.explicit.push(bytes); |
| return this; |
| } |
| |
| addType(type) { |
| // TODO: canonicalize types? |
| this.types.push(type); |
| return this.types.length - 1; |
| } |
| |
| addFunction(name, type) { |
| let type_index = (typeof type) == "number" ? type : this.addType(type); |
| let func = new WasmFunctionBuilder(name, type_index); |
| func.index = this.functions.length; |
| this.functions.push(func); |
| return func; |
| } |
| |
| addImportWithModule(module, name, type) { |
| let type_index = (typeof type) == "number" ? type : this.addType(type); |
| this.imports.push({module: module, name: name, type: type_index}); |
| return this.imports.length - 1; |
| } |
| |
| addImport(name, type) { |
| return this.addImportWithModule(name, undefined, type); |
| } |
| |
| addDataSegment(addr, data, init) { |
| this.segments.push({addr: addr, data: data, init: init}); |
| return this.segments.length - 1; |
| } |
| |
| appendToTable(array) { |
| this.table.push(...array); |
| return this; |
| } |
| |
| toArray(debug) { |
| let binary = new Binary; |
| let wasm = this; |
| |
| // Add header |
| binary.emit_header(); |
| |
| // Add type section |
| if (wasm.types.length > 0) { |
| if (debug) print("emitting types @ " + binary.length); |
| binary.emit_section(kDeclTypes, section => { |
| section.emit_varint(wasm.types.length); |
| for (let type of wasm.types) { |
| section.emit_u8(kWasmFunctionTypeForm); |
| section.emit_varint(type.params.length); |
| for (let param of type.params) { |
| section.emit_u8(param); |
| } |
| section.emit_varint(type.results.length); |
| for (let result of type.results) { |
| section.emit_u8(result); |
| } |
| } |
| }); |
| } |
| |
| // Add imports section |
| if (wasm.imports.length > 0) { |
| if (debug) print("emitting imports @ " + binary.length); |
| binary.emit_section(kDeclImports, section => { |
| section.emit_varint(wasm.imports.length); |
| for (let imp of wasm.imports) { |
| section.emit_varint(imp.type); |
| section.emit_string(imp.module); |
| section.emit_string(imp.name || ''); |
| } |
| }); |
| } |
| |
| // Add functions declarations |
| let has_names = false; |
| let names = false; |
| let exports = 0; |
| if (wasm.functions.length > 0) { |
| if (debug) print("emitting function decls @ " + binary.length); |
| binary.emit_section(kDeclFunctions, section => { |
| section.emit_varint(wasm.functions.length); |
| for (let func of wasm.functions) { |
| has_names = has_names || (func.name != undefined && |
| func.name.length > 0); |
| exports += func.exports.length; |
| section.emit_varint(func.type_index); |
| } |
| }); |
| } |
| |
| // Add table. |
| if (wasm.table.length > 0) { |
| if (debug) print("emitting table @ " + binary.length); |
| binary.emit_section(kDeclTable, section => { |
| section.emit_varint(wasm.table.length); |
| for (let index of wasm.table) { |
| section.emit_varint(index); |
| } |
| }); |
| } |
| |
| // Add memory section |
| if (wasm.memory != undefined) { |
| if (debug) print("emitting memory @ " + binary.length); |
| binary.emit_section(kDeclMemory, section => { |
| section.emit_varint(wasm.memory.min); |
| section.emit_varint(wasm.memory.max); |
| section.emit_u8(wasm.memory.exp ? 1 : 0); |
| }); |
| } |
| |
| |
| // Add export table. |
| if (exports > 0) { |
| if (debug) print("emitting exports @ " + binary.length); |
| binary.emit_section(kDeclExports, section => { |
| section.emit_varint(exports); |
| for (let func of wasm.functions) { |
| for (let exp of func.exports) { |
| section.emit_varint(func.index); |
| section.emit_string(exp); |
| } |
| } |
| }); |
| } |
| |
| // Add start function section. |
| if (wasm.start_index != undefined) { |
| if (debug) print("emitting start function @ " + binary.length); |
| binary.emit_section(kDeclStart, section => { |
| section.emit_varint(wasm.start_index); |
| }); |
| } |
| |
| // Add function bodies. |
| if (wasm.functions.length > 0) { |
| // emit function bodies |
| if (debug) print("emitting code @ " + binary.length); |
| binary.emit_section(kDeclCode, section => { |
| section.emit_varint(wasm.functions.length); |
| for (let func of wasm.functions) { |
| // Function body length will be patched later. |
| let local_decls = []; |
| let l = func.locals; |
| if (l != undefined) { |
| let local_decls_count = 0; |
| if (l.i32_count > 0) { |
| local_decls.push({count: l.i32_count, type: kAstI32}); |
| } |
| if (l.i64_count > 0) { |
| local_decls.push({count: l.i64_count, type: kAstI64}); |
| } |
| if (l.f32_count > 0) { |
| local_decls.push({count: l.f32_count, type: kAstF32}); |
| } |
| if (l.f64_count > 0) { |
| local_decls.push({count: l.f64_count, type: kAstF64}); |
| } |
| } |
| |
| let header = new Binary; |
| header.emit_varint(local_decls.length); |
| for (let decl of local_decls) { |
| header.emit_varint(decl.count); |
| header.emit_u8(decl.type); |
| } |
| |
| section.emit_varint(header.length + func.body.length); |
| section.emit_bytes(header); |
| section.emit_bytes(func.body); |
| } |
| }); |
| } |
| |
| // Add data segments. |
| if (wasm.segments.length > 0) { |
| if (debug) print("emitting data segments @ " + binary.length); |
| binary.emit_section(kDeclData, section => { |
| section.emit_varint(wasm.segments.length); |
| for (let seg of wasm.segments) { |
| section.emit_varint(seg.addr); |
| section.emit_varint(seg.data.length); |
| section.emit_bytes(seg.data); |
| } |
| }); |
| } |
| |
| // Add any explicitly added sections |
| for (let exp of wasm.explicit) { |
| if (debug) print("emitting explicit @ " + binary.length); |
| binary.emit_bytes(exp); |
| } |
| |
| // Add function names. |
| if (has_names) { |
| if (debug) print("emitting names @ " + binary.length); |
| binary.emit_section(kDeclNames, section => { |
| section.emit_varint(wasm.functions.length); |
| for (let func of wasm.functions) { |
| var name = func.name == undefined ? "" : func.name; |
| section.emit_string(name); |
| section.emit_u8(0); // local names count == 0 |
| } |
| }); |
| } |
| |
| // Add an indirect function table pad section. |
| if (wasm.pad !== null) { |
| if (debug) |
| print("emitting indirect function table pad @ " + binary.length); |
| binary.emit_section(kDeclFunctionTablePad, section => { |
| section.emit_varint(wasm.pad); |
| }); |
| } |
| |
| // End the module. |
| if (debug) print("emitting end @ " + binary.length); |
| binary.emit_section(kDeclEnd, section => {}); |
| |
| return binary; |
| } |
| |
| toBuffer(debug) { |
| let bytes = this.toArray(debug); |
| let buffer = new ArrayBuffer(bytes.length); |
| let view = new Uint8Array(buffer); |
| for (let i = 0; i < bytes.length; i++) { |
| let val = bytes[i]; |
| if ((typeof val) == "string") val = val.charCodeAt(0); |
| view[i] = val | 0; |
| } |
| return buffer; |
| } |
| |
| instantiate(...args) { |
| let module = new WebAssembly.Module(this.toBuffer()); |
| let instance = new WebAssembly.Instance(module, ...args); |
| return instance; |
| } |
| } |