ethers.js/packages/asm/lib.esm/assembler.js
2021-10-16 02:29:27 -04:00

1110 lines
42 KiB
JavaScript

"use strict";
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
// @TODO:
// - warn return/revert non-empty, comment ; !assert(+1 @extra)
// - In JS add config (positionIndependent)
// - When checking name collisions, verify no collision in javascript
import { dirname, resolve } from "path";
import vm from "vm";
import { ethers } from "ethers";
import { Opcode } from "./opcodes";
import { parse as _parse, parser as _parser } from "./_parser";
import { version } from "./_version";
const logger = new ethers.utils.Logger(version);
const Guard = {};
function hexConcat(values) {
return ethers.utils.hexlify(ethers.utils.concat(values.map((v) => {
if (v instanceof Opcode) {
return [v.value];
}
if (typeof (v) === "number") {
if (v >= 0 && v <= 255 && !(v % 1)) {
return ethers.utils.hexlify(v);
}
else {
throw new Error("invalid number: " + v);
}
}
return v;
})));
}
function repeat(char, length) {
let result = char;
while (result.length < length) {
result += result;
}
return result.substring(0, length);
}
class Script {
constructor(filename, callback) {
ethers.utils.defineReadOnly(this, "filename", filename);
ethers.utils.defineReadOnly(this, "contextObject", this._baseContext(callback));
ethers.utils.defineReadOnly(this, "context", vm.createContext(this.contextObject));
}
_baseContext(callback) {
return new Proxy({
__filename: this.filename,
__dirname: dirname(this.filename),
console: console,
Uint8Array: Uint8Array,
ethers: ethers,
utils: ethers.utils,
BigNumber: ethers.BigNumber,
arrayify: ethers.utils.arrayify,
concat: hexConcat,
hexlify: ethers.utils.hexlify,
zeroPad: function (value, length) {
return ethers.utils.hexlify(ethers.utils.zeroPad(value, length));
},
id: ethers.utils.id,
keccak256: ethers.utils.keccak256,
namehash: ethers.utils.namehash,
sha256: ethers.utils.sha256,
parseEther: ethers.utils.parseEther,
formatEther: ethers.utils.formatEther,
parseUnits: ethers.utils.parseUnits,
formatUnits: ethers.utils.formatUnits,
randomBytes: function (length) {
return ethers.utils.hexlify(ethers.utils.randomBytes(length));
},
toUtf8Bytes: ethers.utils.toUtf8Bytes,
toUtf8String: ethers.utils.toUtf8String,
formatBytes32String: ethers.utils.formatBytes32String,
parseBytes32String: ethers.utils.parseBytes32String,
Opcode: Opcode,
sighash: function (signature) {
return ethers.utils.id(ethers.utils.FunctionFragment.from(signature).format()).substring(0, 10);
},
topichash: function (signature) {
return ethers.utils.id(ethers.utils.EventFragment.from(signature).format());
},
assemble: assemble,
disassemble: disassemble,
Error: Error
}, {
get: (obj, key) => {
if (obj[key]) {
return obj[key];
}
if (!callback) {
return undefined;
}
return callback(key, this._context.context);
}
});
}
evaluate(code, context) {
return __awaiter(this, void 0, void 0, function* () {
if (this._context) {
throw new Error("evaluation collision");
}
this._context = { context: context };
const script = new vm.Script(code, { filename: this.filename });
let result = script.runInContext(this.context);
if (result instanceof Promise) {
result = yield result;
}
this._context = null;
return result;
});
}
}
let nextTag = 1;
function throwError(message, location) {
return logger.throwError(message, "ASSEMBLER", {
location: location
});
}
export class Node {
constructor(guard, location, options) {
if (guard !== Guard) {
throwError("cannot instantiate class", location);
}
logger.checkAbstract(new.target, Node);
ethers.utils.defineReadOnly(this, "location", Object.freeze(location));
ethers.utils.defineReadOnly(this, "tag", `node-${nextTag++}-${this.constructor.name}`);
for (const key in options) {
ethers.utils.defineReadOnly(this, key, options[key]);
}
}
// Note: EVERY node must call assemble with `this`, even if only with
// the bytes "0x" to trigger the offset and bytecode checks
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
visit(this, "0x");
assembler.end(this);
});
}
children() {
return [];
}
visit(visit) {
visit(this);
this.children().forEach((child) => {
child.visit(visit);
});
}
static from(options) {
const Factories = {
data: DataNode,
decimal: LiteralNode,
eval: EvaluationNode,
exec: ExecutionNode,
hex: LiteralNode,
label: LabelNode,
length: LinkNode,
offset: LinkNode,
opcode: OpcodeNode,
pop: PopNode,
scope: ScopeNode,
};
const factory = Factories[options.type];
if (!factory) {
throwError("unknown type: " + options.type, options.loc);
}
return factory.from(options);
}
}
export class ValueNode extends Node {
constructor(guard, location, options) {
logger.checkAbstract(new.target, ValueNode);
super(guard, location, options);
}
getPushLiteral(value) {
// Convert value into a hexstring
const hex = ethers.utils.hexlify(value);
if (hex === "0x") {
throwError("invalid literal: 0x", this.location);
}
// Make sure it will fit into a push
const length = ethers.utils.hexDataLength(hex);
if (length === 0 || length > 32) {
throwError(`literal out of range: ${hex}`, this.location);
}
return hexConcat([Opcode.from("PUSH" + String(length)), hex]);
}
}
export class LiteralNode extends ValueNode {
constructor(guard, location, value, verbatim) {
super(guard, location, { value, verbatim });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
if (this.verbatim) {
if (this.value.substring(0, 2) === "0x") {
visit(this, this.value);
}
else {
visit(this, ethers.BigNumber.from(this.value).toHexString());
}
}
else {
visit(this, this.getPushLiteral(ethers.BigNumber.from(this.value)));
}
assembler.end(this);
});
}
static from(options) {
if (options.type !== "hex" && options.type !== "decimal") {
throwError("expected hex or decimal type", options.loc);
}
return new LiteralNode(Guard, options.loc, options.value, !!options.verbatim);
}
}
export class PopNode extends ValueNode {
constructor(guard, location, index) {
super(guard, location, { index });
}
get placeholder() {
if (this.index === 0) {
return "$$";
}
return "$" + String(this.index);
}
static from(options) {
return new PopNode(Guard, options.loc, options.index);
}
}
export class LinkNode extends ValueNode {
constructor(guard, location, type, label) {
super(guard, location, { type, label });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
let value = null;
let isOffset = false;
const target = assembler.getTarget(this.label);
if (target instanceof LabelNode) {
if (this.type === "offset") {
value = (assembler.getLinkValue(target, this));
isOffset = true;
}
}
else {
const result = (assembler.getLinkValue(target, this));
if (this.type === "offset") {
value = result.offset;
isOffset = true;
}
else if (this.type === "length") {
value = result.length;
}
}
if (value == null) {
throwError("labels can only be targeted as offsets", this.location);
}
if (isOffset && assembler.positionIndependentCode) {
const here = assembler.getOffset(this, this);
const opcodes = [];
if (here > value) {
// Jump backwards
// Find a literal with length the encodes its own length in the delta
let literal = "0x";
for (let w = 1; w <= 5; w++) {
if (w > 4) {
throwError("jump too large!", this.location);
}
literal = this.getPushLiteral(here - value + w);
if (ethers.utils.hexDataLength(literal) <= w) {
literal = ethers.utils.hexZeroPad(literal, w);
break;
}
}
opcodes.push(literal);
opcodes.push(Opcode.from("PC"));
opcodes.push(Opcode.from("SUB"));
// This also works, in case the above literal thing doesn't work out...
//opcodes.push(Opcode.from("PC"));
//opcodes.push(pushLiteral(-delta));
//opcodes.push(Opcode.from("SWAP1"));
//opcodes.push(Opcode.from("SUB"));
}
else {
// Jump forwards; this is easy to calculate since we can
// do PC firat.
opcodes.push(Opcode.from("PC"));
opcodes.push(this.getPushLiteral(value - here));
opcodes.push(Opcode.from("ADD"));
}
visit(this, hexConcat(opcodes));
}
else {
visit(this, this.getPushLiteral(value));
}
assembler.end(this);
});
}
static from(options) {
// @TODO: Verify type is offset or link...
return new LinkNode(Guard, options.loc, options.type, options.label);
}
}
export class OpcodeNode extends ValueNode {
constructor(guard, location, opcode, operands, instructional) {
super(guard, location, { instructional, opcode, operands });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
// Compute the bytecode in reverse stack order
for (let i = this.operands.length - 1; i >= 0; i--) {
yield this.operands[i].assemble(assembler, visit);
}
// Append this opcode
visit(this, ethers.utils.hexlify(this.opcode.value));
assembler.end(this);
});
}
children() {
return this.operands;
}
visit(visit) {
for (let i = this.operands.length - 1; i >= 0; i--) {
this.operands[i].visit(visit);
}
visit(this);
}
static from(options) {
if (options.type !== "opcode") {
throwError("expected opcode type", options.loc);
}
const opcode = Opcode.from(options.mnemonic);
if (!opcode) {
throwError("unknown opcode: " + options.mnemonic, options.loc);
}
const operands = Object.freeze(options.operands.map((o) => {
const operand = Node.from(o);
if (!(operand instanceof ValueNode)) {
throwError("bad grammar?!", options.loc);
}
return operand;
}));
return new OpcodeNode(Guard, options.loc, opcode, operands, !!options.bare);
}
}
export class LabelledNode extends Node {
constructor(guard, location, name, values) {
logger.checkAbstract(new.target, LabelledNode);
values = ethers.utils.shallowCopy(values || {});
values.name = name;
super(guard, location, values);
}
}
export class LabelNode extends LabelledNode {
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
visit(this, ethers.utils.hexlify(Opcode.from("JUMPDEST").value));
assembler.end(this);
});
}
static from(options) {
if (options.type !== "label") {
throwError("expected label type", options.loc);
}
return new LabelNode(Guard, options.loc, options.name);
}
}
export class PaddingNode extends ValueNode {
constructor(guard, location) {
super(guard, location, {});
this._length = 0;
}
setLength(length) {
this._length = length;
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
const padding = new Uint8Array(this._length);
padding.fill(0);
visit(this, ethers.utils.hexlify(padding));
assembler.end(this);
});
}
}
export class DataNode extends LabelledNode {
constructor(guard, location, name, data) {
super(guard, location, name, { data });
ethers.utils.defineReadOnly(this, "padding", new PaddingNode(Guard, this.location));
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
// @TODO: This is a problem... We need to visit before visiting children
// so offsets are correct, but then we cannot pad...
visit(this, "0x");
for (let i = 0; i < this.data.length; i++) {
yield this.data[i].assemble(assembler, visit);
}
// We pad data if is contains PUSH opcodes that would overrun
// the data, which could eclipse valid operations (since the
// VM won't execute or jump within PUSH operations)
const bytecode = ethers.utils.concat(this.data.map((d) => assembler.getBytecode(d)));
// Replay the data as bytecode, skipping PUSH data
let i = 0;
while (i < bytecode.length) {
const opcode = Opcode.from(bytecode[i++]);
if (opcode) {
i += opcode.isPush();
}
}
// The amount we overshot the data by is how much padding we need
this.padding.setLength(i - bytecode.length);
yield this.padding.assemble(assembler, visit);
assembler.end(this);
});
}
children() {
const children = this.data.slice();
children.push(this.padding);
return children;
}
static from(options) {
if (options.type !== "data") {
throwError("expected data type", options.loc);
}
return new DataNode(Guard, options.loc, options.name, Object.freeze(options.data.map((d) => Node.from(d))));
}
}
export class EvaluationNode extends ValueNode {
constructor(guard, location, script, verbatim) {
super(guard, location, { script, verbatim });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
const result = yield assembler.evaluate(this.script, this);
if (this.verbatim) {
if (typeof (result) === "number") {
visit(this, ethers.BigNumber.from(result).toHexString());
}
else {
visit(this, ethers.utils.hexlify(result));
}
}
else {
visit(this, this.getPushLiteral(result));
}
assembler.end(this);
});
}
static from(options) {
if (options.type !== "eval") {
throwError("expected eval type", options.loc);
}
return new EvaluationNode(Guard, options.loc, options.script, !!options.verbatim);
}
}
export class ExecutionNode extends Node {
constructor(guard, location, script) {
super(guard, location, { script });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
yield assembler.evaluate(this.script, this);
assembler.end(this);
});
}
static from(options) {
if (options.type !== "exec") {
throwError("expected exec type", options.loc);
}
return new ExecutionNode(Guard, options.loc, options.script);
}
}
export class ScopeNode extends LabelledNode {
constructor(guard, location, name, statements) {
super(guard, location, name, { statements });
}
assemble(assembler, visit) {
return __awaiter(this, void 0, void 0, function* () {
assembler.start(this);
visit(this, "0x");
for (let i = 0; i < this.statements.length; i++) {
yield this.statements[i].assemble(assembler, visit);
}
assembler.end(this);
});
}
children() {
return this.statements;
}
static from(options) {
if (options.type !== "scope") {
throwError("expected scope type", options.loc);
}
return new ScopeNode(Guard, options.loc, options.name, Object.freeze(options.statements.map((s) => Node.from(s))));
}
}
export function disassemble(bytecode) {
const ops = [];
const offsets = {};
const bytes = ethers.utils.arrayify(bytecode, { allowMissingPrefix: true });
let i = 0;
let oob = false;
while (i < bytes.length) {
let opcode = Opcode.from(bytes[i]);
if (!opcode) {
opcode = new Opcode(`unknown (${ethers.utils.hexlify(bytes[i])})`, bytes[i], 0, 0);
}
else if (oob && opcode.mnemonic === "JUMPDEST") {
opcode = new Opcode(`JUMPDEST (invalid; OOB!!)`, bytes[i], 0, 0);
}
const op = {
opcode: opcode,
offset: i,
length: 1
};
offsets[i] = op;
ops.push(op);
i++;
const push = opcode.isPush();
if (push) {
const data = ethers.utils.hexlify(bytes.slice(i, i + push));
if (ethers.utils.hexDataLength(data) === push) {
op.pushValue = data;
op.length += push;
i += push;
}
else {
oob = true;
}
}
}
ops.getOperation = function (offset) {
if (offset >= bytes.length) {
return {
opcode: Opcode.from("STOP"),
offset: offset,
length: 1
};
}
return (offsets[offset] || null);
};
ops.getByte = function (offset) {
if (offset >= bytes.length) {
return 0x00;
}
return bytes[offset];
};
ops.getBytes = function (offset, length) {
const result = new Uint8Array(length);
result.fill(0);
if (offset < bytes.length) {
result.set(bytes.slice(offset));
}
return ethers.utils.arrayify(result);
};
ops.byteLength = bytes.length;
return ops;
}
export function formatBytecode(bytecode) {
const lines = [];
bytecode.forEach((op) => {
const opcode = op.opcode;
let offset = ethers.utils.hexZeroPad(ethers.utils.hexlify(op.offset), 2);
if (opcode.isValidJumpDest()) {
offset += "*";
}
else {
offset += " ";
}
let operation = opcode.mnemonic;
const push = opcode.isPush();
if (push) {
if (op.pushValue) {
operation = op.pushValue + `${repeat(" ", 67 - op.pushValue.length)}; #${push} `;
}
else {
operation += `${repeat(" ", 67 - operation.length)}; OOB!! `;
}
}
lines.push(`${offset.substring(2)}: ${operation}`);
});
return lines.join("\n");
}
class Assembler {
constructor(root, positionIndependentCode) {
ethers.utils.defineReadOnly(this, "root", root);
ethers.utils.defineReadOnly(this, "positionIndependentCode", !!positionIndependentCode);
const nodes = {};
const labels = {};
const parents = {};
// Link labels to their target node
root.visit((node) => {
nodes[node.tag] = {
node: node,
offset: 0x0,
bytecode: "0x"
};
if (node instanceof LabelledNode) {
// Check for duplicate labels
if (labels[node.name]) {
logger.throwError(("duplicate label: " + node.name), ethers.utils.Logger.errors.UNSUPPORTED_OPERATION, {});
}
labels[node.name] = node;
}
});
root.visit((node) => {
// Check all labels exist
if (node instanceof LinkNode) {
const target = labels[node.label];
if (!target) {
logger.throwError(("missing label: " + node.label), ethers.utils.Logger.errors.UNSUPPORTED_OPERATION, {});
}
}
// Build the parent structure
node.children().forEach((child) => {
parents[child.tag] = node;
});
});
ethers.utils.defineReadOnly(this, "labels", Object.freeze(labels));
ethers.utils.defineReadOnly(this, "nodes", Object.freeze(nodes));
ethers.utils.defineReadOnly(this, "_parents", Object.freeze(parents));
}
// Link operations
getTarget(label) {
return this.labels[label];
}
// Evaluate script in the context of a {{! }} or {{= }}
evaluate(script, source) {
return Promise.resolve(new Uint8Array(0));
}
getAncestor(node, cls) {
node = this._parents[node.tag];
while (node) {
if (node instanceof cls) {
return node;
}
node = this._parents[node.tag];
}
return null;
}
getOffset(node, source) {
const offset = this.nodes[node.tag].offset;
if (source == null) {
return offset;
}
const sourceScope = ((source instanceof ScopeNode) ? source : this.getAncestor(source, ScopeNode));
return offset - this.nodes[sourceScope.tag].offset;
}
setOffset(node, offset) {
this.nodes[node.tag].offset = offset;
}
getBytecode(node) {
return this.nodes[node.tag].bytecode;
}
setBytecode(node, bytecode) {
this.nodes[node.tag].bytecode = bytecode;
}
getLinkValue(target, source) {
const sourceScope = ((source instanceof ScopeNode) ? source : this.getAncestor(source, ScopeNode));
const targetScope = ((target instanceof ScopeNode) ? target : this.getAncestor(target, ScopeNode));
if (target instanceof LabelNode) {
// Label offset (e.g. "@foo:"); accessible only within its direct scope
//const scope = this.getAncestor(source, Scope);
if (targetScope !== sourceScope) {
throwError(`cannot access ${target.name} from ${source.tag}`, source.location);
}
// Return the offset relative to its scope
return this.nodes[target.tag].offset - this.nodes[targetScope.tag].offset;
}
const info = this.nodes[target.tag];
// Return the offset is relative to its scope
const bytes = Array.prototype.slice.call(ethers.utils.arrayify(info.bytecode));
ethers.utils.defineReadOnly(bytes, "ast", target);
ethers.utils.defineReadOnly(bytes, "source", target.location.source);
if (!((target instanceof DataNode) || (target instanceof ScopeNode))) {
throwError("invalid link value lookup", source.location);
}
// Check that target is any descendant (or self) of the source scope
let safeOffset = (sourceScope == targetScope);
if (!safeOffset) {
sourceScope.visit((node) => {
if (node === targetScope) {
safeOffset = true;
}
});
}
// Not safe to access the offset; this will fault if anything tries.
if (!safeOffset) {
Object.defineProperty(bytes, "offset", {
get: function () { throwError(`cannot access ${target.name}.offset from ${source.tag}`, this.location); }
});
ethers.utils.defineReadOnly(bytes, "_freeze", function () { });
}
// Add the offset relative to the scope; unless the offset has
// been marked as invalid, in which case accessing it will fail
if (safeOffset) {
bytes.offset = info.offset - this.nodes[sourceScope.tag].offset;
let frozen = false;
ethers.utils.defineReadOnly(bytes, "_freeze", function () {
if (frozen) {
return;
}
frozen = true;
ethers.utils.defineReadOnly(bytes, "offset", bytes.offset);
});
}
return bytes;
}
start(node) { }
end(node) { }
}
export var SemanticErrorSeverity;
(function (SemanticErrorSeverity) {
SemanticErrorSeverity["error"] = "error";
SemanticErrorSeverity["warning"] = "warning";
})(SemanticErrorSeverity || (SemanticErrorSeverity = {}));
;
// This Assembler is designed to only check for errors and warnings
// Warnings
// - Bare PUSH opcodes
// - Instructional opcode that has parameters
// Errors
// - Using a $$ outside of RPN
// - Using a $$ when it is not adjacent to the stack
// - The operand count does not match the opcode
// - An opcode is used as an operand but does not return a value
class SemanticChecker extends Assembler {
check() {
const errors = [];
this.root.visit((node) => {
if (node instanceof OpcodeNode) {
const opcode = node.opcode;
if (node.instructional) {
if (opcode.delta) {
errors.push({
message: `${opcode.mnemonic} used as instructional`,
severity: SemanticErrorSeverity.warning,
node: node
});
}
}
else {
if (opcode.mnemonic === "POP") {
if (node.operands.length !== 0) {
errors.push({
message: "POP expects 0 operands",
severity: SemanticErrorSeverity.error,
node: node
});
}
}
else if (node.operands.length !== opcode.delta) {
errors.push({
message: `${opcode.mnemonic} expects ${opcode.delta} operands`,
severity: SemanticErrorSeverity.error,
node: node
});
}
}
if (opcode.isPush()) {
// A stray PUSH operation will gobble up the following code
// bytes which is bad. But this may be a disassembled program
// and that PUSH may actually be just some data (which is safe)
errors.push({
message: "PUSH opcode modifies program flow - use literals instead",
severity: SemanticErrorSeverity.warning,
node: node
});
}
else if (!node.location.statement && opcode.alpha !== 1) {
// If an opcode does not push anything on the stack, it
// cannot be used as an operand
errors.push({
message: `${node.opcode.mnemonic} cannot be an operand`,
severity: SemanticErrorSeverity.error,
node: node
});
}
}
if (node.location.statement) {
if (node instanceof PopNode) {
// $$ by itself is useless and is intended to be an operand
errors.push({
message: `$$ must be an operand`,
severity: SemanticErrorSeverity.error,
node: node
});
}
else {
const scope = this.getAncestor(node, ScopeNode);
// Make sure any $$ is stack adjacent (within this scope)
const ordered = [];
node.visit((node) => {
if (scope !== this.getAncestor(node, ScopeNode)) {
return;
}
ordered.push(node);
});
// Allow any number of stack adjacent $$
let foundZero = null;
let lastIndex = 0;
while (ordered.length && ordered[0] instanceof PopNode) {
const popNode = (ordered.shift());
const index = popNode.index;
if (index === 0) {
foundZero = popNode;
}
else if (index !== lastIndex + 1) {
errors.push({
message: `out-of-order stack placeholder ${popNode.placeholder}; expected $$${lastIndex + 1}`,
severity: SemanticErrorSeverity.error,
node: popNode
});
while (ordered.length && ordered[0] instanceof PopNode) {
ordered.shift();
}
break;
}
else {
lastIndex = index;
}
}
if (foundZero && lastIndex > 0) {
errors.push({
message: "cannot mix $$ and $1 stack placeholder",
severity: SemanticErrorSeverity.error,
node: foundZero
});
}
// If there are still any buried, we have a problem
const pops = ordered.filter((n) => (n instanceof PopNode));
if (pops.length) {
errors.push({
message: `stack placeholder ${(pops[0]).placeholder} must be stack adjacent`,
severity: SemanticErrorSeverity.error,
node: pops[0]
});
}
}
}
});
return errors;
}
}
class CodeGenerationAssembler extends Assembler {
constructor(root, options) {
super(root, !!options.positionIndependentCode);
ethers.utils.defineReadOnly(this, "retry", ((options.retry != null) ? options.retry : 512));
ethers.utils.defineReadOnly(this, "filename", resolve(options.filename || "./contract.asm"));
ethers.utils.defineReadOnly(this, "defines", Object.freeze(options.defines || {}));
ethers.utils.defineReadOnly(this, "_stack", []);
this.reset();
}
_didChange() {
this._changed = true;
}
get changed() {
return this._changed;
}
// Reset the assembler for another run with updated values
reset() {
this._changed = false;
this._objectCache = {};
this._nextBytecode = {};
this._script = new Script(this.filename, (name, context) => {
return this.get(name, context);
});
this._checks = [];
}
evaluate(script, source) {
return this._script.evaluate(script, source);
}
_runChecks() {
this._checks.forEach((func) => {
if (!func()) {
this._didChange();
}
});
}
getLinkValue(target, source) {
// Since we are iteratively generating code, offsets and lengths
// may not be stable at any given point in time, so if an offset
// is negative the code is obviously wrong, however we set it to
// 0 so we can proceed with generation to fill in as many blanks
// as possible; then we will try assembling again
const result = super.getLinkValue(target, source);
if (typeof (result) === "number") {
if (result < 0) {
this._checks.push(() => false);
return 0;
}
this._checks.push(() => {
return (super.getLinkValue(target, source) === result);
});
return result;
}
// The offset cannot be used so is independent
try {
if (result.offset < 0) {
this._checks.push(() => false);
result.offset = 0;
//this._didChange();
}
else {
this._checks.push(() => {
const check = super.getLinkValue(target, source);
if (check.offset === result.offset && ethers.utils.hexlify(check) === ethers.utils.hexlify(result)) {
return true;
}
return false;
});
}
}
catch (error) {
this._checks.push(() => {
const check = super.getLinkValue(target, source);
return (ethers.utils.hexlify(check) === ethers.utils.hexlify(result));
});
}
return result;
}
start(node) {
this._stack.push(node);
//this._oldBytecode[node.tag] = this.getBytecode(node);
//this.setBytecode(node, "0x");
this._nextBytecode[node.tag] = "0x";
}
end(node) {
if (this._stack.pop() !== node) {
throwError("missing push/pop pair", node.location);
}
const oldBytecode = this.getBytecode(node);
this.setBytecode(node, this._nextBytecode[node.tag]);
if (!(node instanceof PaddingNode)) {
this._checks.push(() => {
return (oldBytecode === this.getBytecode(node));
});
}
}
// This is used by evaluate to access properties in JavaScript
// - "defines" allow meta-programming values to be used
// - jump destinations are available as numbers
// - bytecode and data are available as an immutable DataSource
get(name, source) {
if (name === "defines") {
return this.defines;
}
else if (name === "_ok") {
this._runChecks();
return !this._didChange;
}
const node = this.labels[name];
if (!node) {
return undefined;
}
// We cache objects when they are generated so all nodes
// receive consistent data; if there is a change we will
// run the entire assembly process again with the updated
// values
if (this._objectCache[node.tag] == null) {
const result = this.getLinkValue(node, source);
if (typeof (result) !== "number") {
result._freeze();
}
this._objectCache[node.tag] = result;
}
return this._objectCache[node.tag];
}
_assemble() {
return __awaiter(this, void 0, void 0, function* () {
let offset = 0;
yield this.root.assemble(this, (node, bytecode) => {
// Things have moved; we will need to try again
if (this.getOffset(node) !== offset) {
this.setOffset(node, offset);
//this._didChange();
this._checks.push(() => false);
}
this._stack.forEach((node) => {
this._nextBytecode[node.tag] = hexConcat([
this._nextBytecode[node.tag],
bytecode
]);
});
offset += ethers.utils.hexDataLength(bytecode);
});
this._runChecks();
});
}
assemble(label) {
return __awaiter(this, void 0, void 0, function* () {
if (label == null) {
label = "_";
}
const target = this.getTarget(label);
if (!target) {
logger.throwArgumentError(`unknown labelled target: ${label}`, "label", label);
}
else if (!(target instanceof ScopeNode || target instanceof DataNode)) {
logger.throwArgumentError(`cannot assemble a bodyless label: ${label}`, "label", label);
}
// Continue re-evaluating the bytecode until a stable set of
// offsets, length and values are reached.
yield this._assemble();
for (let i = 0; i < this.retry; i++) {
// Regenerate the code with the updated assembler values
this.reset();
yield this._assemble();
// Generated bytecode is stable!! :)
if (!this.changed) {
// This should not happen; something is wrong with the grammar
// or missing enter/exit call in assemble
if (this._stack.length !== 0) {
throwError("Bad AST! Bad grammar?!", null);
}
//console.log(`Assembled in ${ i } attempts`);
return this.getBytecode(target);
}
}
return logger.throwError(`unable to assemble; ${this.retry} attempts failed to generate stable bytecode`, ethers.utils.Logger.errors.UNKNOWN_ERROR, {});
});
}
}
export function parse(code, options) {
if (options == null) {
options = {};
}
// Since Jison allows \n, \r or \r\n line endings, we need some
// tweaking to get the correct position
const lines = [];
let offset = 0;
code.split(/(\r\n?|\n)/g).forEach((clump, index) => {
if (index % 2) {
lines[lines.length - 1].line += clump;
}
else {
lines.push({ line: clump, offset: offset });
}
offset += clump.length;
});
// Add a mock-EOF to the end of the file so we don't out-of-bounds
// on the last character
if (lines.length) {
lines[lines.length - 1].line += "\n";
}
// Givens a line (1 offset) and column (0 offset) return the byte offset
const getOffset = function (line, column) {
const info = lines[line - 1];
if (!info || column >= info.line.length) {
throw new Error("out of range");
}
return info.offset + column;
};
// We use this in the _parser to convert locations to source
_parser.yy._ethersLocation = function (loc) {
// The _ scope should call with null to get the full source
if (loc == null) {
return {
offset: 0,
line: 0,
length: code.length,
source: code,
statement: true
};
}
const offset = getOffset(loc.first_line, loc.first_column);
const end = getOffset(loc.last_line, loc.last_column);
return {
offset: offset,
line: loc.first_line - 1,
length: (end - offset),
source: code.substring(offset, end),
statement: (!!loc.statement)
};
};
const result = Node.from(_parse(code));
// Nuke the source code lookup callback
_parser.yy._ethersLocation = null;
// Semantic Checks
const checker = new SemanticChecker(result);
const errors = checker.check();
if (errors.filter((e) => (e.severity === SemanticErrorSeverity.error)).length || (errors.length && !options.ignoreWarnings)) {
const error = new Error("semantic errors during parsing");
error.errors = errors;
throw error;
}
return result;
}
export function assemble(ast, options) {
return __awaiter(this, void 0, void 0, function* () {
const assembler = new CodeGenerationAssembler(ast, options || {});
return assembler.assemble(options.target || "_");
});
}
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