Revert of [wasm] Add a JavaScript utility to make it easier to build WASM modules from JavaScript.

test/mjsunit/wasm/wasm-module-builder.js

-// 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.
-
-function StringRef(string) {
-    this.pos = -1;
-    this.string = string;
-}
-
-function DataRef(data) {
-    this.pos = -1;
-    this.data = data;
-}
-
-function WasmFunctionBuilder(name, sig_index) {
-    this.name = name;
-    this.sig_index = sig_index;
-    this.exports = [];
-}
-
-WasmFunctionBuilder.prototype.exportAs = function(name) {
-    this.exports.push(name);
-    return this;
-}
-
-WasmFunctionBuilder.prototype.addBody = function(body) {
-    this.body = body;
-    return this;
-}
-
-WasmFunctionBuilder.prototype.addLocals = function(locals) {
-    this.locals = locals;
-    return this;
-}
-
-function WasmModuleBuilder() {
-    this.signatures = [];
-    this.imports = [];
-    this.functions = [];
-    this.exports = [];
-    this.function_table = [];
-    this.data_segments = [];
-    return this;
-}
-
-WasmModuleBuilder.prototype.addMemory = function(min, max, exp) {
-    this.memory = {min: min, max: max, exp: exp};
-    return this;
-}
-
-// Add a signature; format is [rettype, param0, param1, ...]
-WasmModuleBuilder.prototype.addSignature = function(sig) {
-    // TODO: canonicalize signatures?
-    this.signatures.push(sig);
-    return this.signatures.length - 1;
-}
-
-WasmModuleBuilder.prototype.addFunction = function(name, sig) {
-    var sig_index = (typeof sig) == "number" ? sig : this.addSignature(sig);
-    var func = new WasmFunctionBuilder(name, sig_index);
-    func.index = this.functions.length;
-    this.functions.push(func);
-    return func;
-}
-
-WasmModuleBuilder.prototype.addImport = function(name, sig) {
-    var sig_index = (typeof sig) == "number" ? sig : this.addSignature(sig);
-    this.imports.push({name: name, sig_index: sig_index});
-    return this.imports.length - 1;
-}
-
-WasmModuleBuilder.prototype.addDataSegment = function(addr, data, init) {
-    this.data_segments.push({addr: addr, data: data, init: init});
-    return this.data_segments.length - 1;
-}
-
-WasmModuleBuilder.prototype.appendToFunctionTable = function(array) {
-    this.function_table = this.function_table.concat(array);
-    return this;
-}
-
-function emit_u8(bytes, val) {
-    bytes.push(val & 0xff);
-}
-
-function emit_u16(bytes, val) {
-    bytes.push(val & 0xff);
-    bytes.push((val >> 8) & 0xff);
-}
-
-function emit_u32(bytes, val) {
-    bytes.push(val & 0xff);
-    bytes.push((val >> 8) & 0xff);
-    bytes.push((val >> 16) & 0xff);
-    bytes.push((val >> 24) & 0xff);
-}
-
-function emit_string(bytes, string) {
-    bytes.push(new StringRef(string));
-    bytes.push(0);
-    bytes.push(0);
-    bytes.push(0);
-}
-
-function emit_data_ref(bytes, string) {
-    bytes.push(new DataRef(string));
-    bytes.push(0);
-    bytes.push(0);
-    bytes.push(0);
-}
-
-function emit_varint(bytes, val) {
-    while (true) {
-        var v = val & 0xff;
-        val = val >>> 7;
-        if (val == 0) {
-            bytes.push(v);
-            break;
-        }
-        bytes.push(v | 0x80);
-    }
-}
-
-WasmModuleBuilder.prototype.toArray = function(debug) {
-    // Add header bytes
-    var bytes = [];
-    bytes = bytes.concat([kWasmH0, kWasmH1, kWasmH2, kWasmH3,
-                          kWasmV0, kWasmV1, kWasmV2, kWasmV3]);
-
-    // Add memory section
-    if (this.memory != undefined) {
-        if (debug) print("emitting memory @ " + bytes.length);
-        emit_u8(bytes, kDeclMemory);
-        emit_varint(bytes, this.memory.min);
-        emit_varint(bytes, this.memory.max);
-        emit_u8(bytes, this.memory.exp ? 1 : 0);
-    }
-
-    // Add signatures section
-    if (this.signatures.length > 0) {
-        if (debug) print("emitting signatures @ " + bytes.length);
-        emit_u8(bytes, kDeclSignatures);
-        emit_varint(bytes, this.signatures.length);
-        for (sig of this.signatures) {
-            var params = sig.length - 1;
-            emit_u8(bytes, params);
-            for (var j = 0; j < sig.length; j++) {
-                emit_u8(bytes, sig[j]);
-            }
-        }
-    }
-
-    // Add imports section
-    if (this.imports.length > 0) {
-        if (debug) print("emitting imports @ " + bytes.length);
-        emit_u8(bytes, kDeclImportTable);
-        emit_varint(bytes, this.imports.length);
-        for (imp of this.imports) {
-            emit_u16(bytes, imp.sig_index);
-            emit_string(bytes, "");
-            emit_string(bytes, imp.name);
-        }
-    }
-
-    // Add functions section
-    var names = false;
-    var exports = 0;
-    if (this.functions.length > 0) {
-        if (debug) print("emitting functions @ " + bytes.length);
-        emit_u8(bytes, kDeclFunctions);
-        emit_varint(bytes, this.functions.length);
-        var index = 0;
-        for (func of this.functions) {
-            var flags = 0;
-            var hasName = func.name != undefined && func.name.length > 0;
-            names = names || hasName;
-            if (hasName) flags |= kDeclFunctionName;
-            if (func.locals != undefined) flags |= kDeclFunctionLocals;
-            exports += func.exports.length;
-
-            emit_u8(bytes, flags);
-            emit_u16(bytes, func.sig_index);
-
-            if (hasName) {
-                emit_string(bytes, func.name);
-            }
-            if (func.locals != undefined) {
-                emit_u16(bytes, func.locals.i32_count);
-                emit_u16(bytes, func.locals.i64_count);
-                emit_u16(bytes, func.locals.f32_count);
-                emit_u16(bytes, func.locals.f64_count);
-            }
-            emit_u16(bytes, func.body.length);
-            for (var i = 0; i < func.body.length; i++) {
-                emit_u8(bytes, func.body[i]);
-            }
-
-            index++;
-        }
-    }
-
-    if (this.function_table.length > 0) {
-        if (debug) print("emitting function table @ " + bytes.length);
-        emit_u8(bytes, kDeclFunctionTable);
-        emit_varint(bytes, this.function_table.length);
-        for (index of this.function_table) {
-            emit_u16(bytes, index);
-        }
-    }
-
-    if (exports > 0) {
-        if (debug) print("emitting exports @ " + bytes.length);
-        emit_u8(bytes, kDeclExportTable);
-        emit_varint(bytes, exports);
-        for (func of this.functions) {
-            for (exp of func.exports) {
-                emit_u16(bytes, func.index);
-                emit_string(bytes, exp);
-            }
-        }
-    }
-
-    if (this.data_segments.length > 0) {
-        if (debug) print("emitting data segments @ " + bytes.length);
-        emit_u8(bytes, kDeclDataSegments);
-        emit_varint(bytes, this.data_segments.length);
-        for (seg of this.data_segments) {
-            emit_u32(bytes, seg.addr);
-            emit_data_ref(bytes, seg.data);
-            emit_u32(bytes, seg.data.length);
-            emit_u8(bytes, seg.init ? 1 : 0);
-        }
-    }
-
-    // End the module.
-    if (debug) print("emitting end @ " + bytes.length);
-    emit_u8(bytes, kDeclEnd);
-
-    // Collect references and canonicalize strings.
-    var strings = new Object();
-    var data_segments = [];
-    var count = 0;
-    for (var i = 0; i < bytes.length; i++) {
-        var b = bytes[i];
-        if (b instanceof StringRef) {
-            count++;
-            var prev = strings[b.string];
-            if (prev) {
-                bytes[i] = prev;
-            } else {
-                strings[b.string] = b;
-            }
-        }
-        if (b instanceof DataRef) {
-            data_segments.push(b);
-            count++;
-        }
-    }
-
-    if (count > 0) {
-        // Emit strings.
-        if (debug) print("emitting strings @ " + bytes.length);
-        for (str in strings) {
-            var ref = strings[str];
-            if (!(ref instanceof StringRef)) continue;
-            if (debug) print("  \"" + str + "\" @ " + bytes.length);
-            ref.pos = bytes.length;
-            for (var i = 0; i < str.length; i++) {
-                emit_u8(bytes, str.charCodeAt(i));
-            }
-            emit_u8(bytes, 0);  // null terminator.
-        }
-        // Emit data.
-        if (debug) print("emitting data @ " + bytes.length);
-        for (ref of data_segments) {
-            ref.pos = bytes.length;
-            for (var i = 0; i < ref.data.length; i++) {
-                emit_u8(bytes, ref.data[i]);
-            }
-        }
-        // Update references to strings and data.
-        for (var i = 0; i < bytes.length; i++) {
-            var b = bytes[i];
-            if (b instanceof StringRef || b instanceof DataRef) {
-                bytes[i] = b.pos & 0xFF;
-                bytes[i + 1] = (b.pos >> 8) & 0xFF;
-                bytes[i + 2] = (b.pos >> 16) & 0xFF;
-                bytes[i + 3] = (b.pos >> 24) & 0xFF;
-            }
-        }
-    }
-
-    return bytes;
-}
-
-WasmModuleBuilder.prototype.toBuffer = function(debug) {
-    var bytes = this.toArray(debug);
-    var buffer = new ArrayBuffer(bytes.length);
-    var view = new Uint8Array(buffer);
-    for (var i = 0; i < bytes.length; i++) {
-        var val = bytes[i];
-        if ((typeof val) == "string") val = val.charCodeAt(0);
-        view[i] = val | 0;
-    }
-    return buffer;
-}
-
-WasmModuleBuilder.prototype.instantiate = function(ffi) {
-    var buffer = this.toBuffer();
-    return _WASMEXP_.instantiateModule(buffer, ffi);
-}