gecko-dev/toolkit/devtools/acorn/acorn_loose.js

778 строки
24 KiB
JavaScript

// Acorn: Loose parser
//
// This module provides an alternative parser (`parse_dammit`) that
// exposes that same interface as `parse`, but will try to parse
// anything as JavaScript, repairing syntax error the best it can.
// There are circumstances in which it will raise an error and give
// up, but they are very rare. The resulting AST will be a mostly
// valid JavaScript AST (as per the [Mozilla parser API][api], except
// that:
//
// - Return outside functions is allowed
//
// - Label consistency (no conflicts, break only to existing labels)
// is not enforced.
//
// - Bogus Identifier nodes with a name of `"✖"` are inserted whenever
// the parser got too confused to return anything meaningful.
//
// [api]: https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API
//
// The expected use for this is to *first* try `acorn.parse`, and only
// if that fails switch to `parse_dammit`. The loose parser might
// parse badly indented code incorrectly, so **don't** use it as
// your default parser.
//
// Quite a lot of acorn.js is duplicated here. The alternative was to
// add a *lot* of extra cruft to that file, making it less readable
// and slower. Copying and editing the code allowed me to make
// invasive changes and simplifications without creating a complicated
// tangle.
(function(root, mod) {
if (typeof exports == "object" && typeof module == "object") return mod(exports, require("./acorn")); // CommonJS
if (typeof define == "function" && define.amd) return define(["exports", "./acorn"], mod); // AMD
mod(root.acorn || (root.acorn = {}), root.acorn); // Plain browser env
})(this, function(exports, acorn) {
"use strict";
var tt = acorn.tokTypes;
var options, input, fetchToken, context;
exports.parse_dammit = function(inpt, opts) {
if (!opts) opts = {};
input = String(inpt);
options = opts;
if (!opts.tabSize) opts.tabSize = 4;
fetchToken = acorn.tokenize(inpt, opts);
sourceFile = options.sourceFile || null;
context = [];
nextLineStart = 0;
ahead.length = 0;
next();
return parseTopLevel();
};
var lastEnd, token = {start: 0, end: 0}, ahead = [];
var curLineStart, nextLineStart, curIndent, lastEndLoc, sourceFile;
function next() {
lastEnd = token.end;
if (options.locations)
lastEndLoc = token.endLoc;
if (ahead.length)
token = ahead.shift();
else
token = readToken();
if (token.start >= nextLineStart) {
while (token.start >= nextLineStart) {
curLineStart = nextLineStart;
nextLineStart = lineEnd(curLineStart) + 1;
}
curIndent = indentationAfter(curLineStart);
}
}
function readToken() {
for (;;) {
try {
return fetchToken();
} catch(e) {
if (!(e instanceof SyntaxError)) throw e;
// Try to skip some text, based on the error message, and then continue
var msg = e.message, pos = e.raisedAt, replace = true;
if (/unterminated/i.test(msg)) {
pos = lineEnd(e.pos);
if (/string/.test(msg)) {
replace = {start: e.pos, end: pos, type: tt.string, value: input.slice(e.pos + 1, pos)};
} else if (/regular expr/i.test(msg)) {
var re = input.slice(e.pos, pos);
try { re = new RegExp(re); } catch(e) {}
replace = {start: e.pos, end: pos, type: tt.regexp, value: re};
} else {
replace = false;
}
} else if (/invalid (unicode|regexp|number)|expecting unicode|octal literal|is reserved|directly after number/i.test(msg)) {
while (pos < input.length && !isSpace(input.charCodeAt(pos))) ++pos;
} else if (/character escape|expected hexadecimal/i.test(msg)) {
while (pos < input.length) {
var ch = input.charCodeAt(pos++);
if (ch === 34 || ch === 39 || isNewline(ch)) break;
}
} else if (/unexpected character/i.test(msg)) {
pos++;
replace = false;
} else {
throw e;
}
resetTo(pos);
if (replace === true) replace = {start: pos, end: pos, type: tt.name, value: "✖"};
if (replace) {
if (options.locations) {
replace.startLoc = acorn.getLineInfo(input, replace.start);
replace.endLoc = acorn.getLineInfo(input, replace.end);
}
return replace;
}
}
}
}
function resetTo(pos) {
var ch = input.charAt(pos - 1);
var reAllowed = !ch || /[\[\{\(,;:?\/*=+\-~!|&%^<>]/.test(ch) ||
/[enwfd]/.test(ch) && /\b(keywords|case|else|return|throw|new|in|(instance|type)of|delete|void)$/.test(input.slice(pos - 10, pos));
fetchToken.jumpTo(pos, reAllowed);
}
function copyToken(token) {
var copy = {start: token.start, end: token.end, type: token.type, value: token.value};
if (options.locations) {
copy.startLoc = token.startLoc;
copy.endLoc = token.endLoc;
}
return copy;
}
function lookAhead(n) {
// Copy token objects, because fetchToken will overwrite the one
// it returns, and in this case we still need it
if (!ahead.length)
token = copyToken(token);
while (n > ahead.length)
ahead.push(copyToken(readToken()));
return ahead[n-1];
}
var newline = /[\n\r\u2028\u2029]/;
function isNewline(ch) {
return ch === 10 || ch === 13 || ch === 8232 || ch === 8329;
}
function isSpace(ch) {
return (ch < 14 && ch > 8) || ch === 32 || ch === 160 || isNewline(ch);
}
function pushCx() {
context.push(curIndent);
}
function popCx() {
curIndent = context.pop();
}
function lineEnd(pos) {
while (pos < input.length && !isNewline(input.charCodeAt(pos))) ++pos;
return pos;
}
function indentationAfter(pos) {
for (var count = 0;; ++pos) {
var ch = input.charCodeAt(pos);
if (ch === 32) ++count;
else if (ch === 9) count += options.tabSize;
else return count;
}
}
function closes(closeTok, indent, line, blockHeuristic) {
if (token.type === closeTok || token.type === tt.eof) return true;
if (line != curLineStart && curIndent < indent && tokenStartsLine() &&
(!blockHeuristic || nextLineStart >= input.length ||
indentationAfter(nextLineStart) < indent)) return true;
return false;
}
function tokenStartsLine() {
for (var p = token.start - 1; p >= curLineStart; --p) {
var ch = input.charCodeAt(p);
if (ch !== 9 && ch !== 32) return false;
}
return true;
}
function node_t(start) {
this.type = null;
this.start = start;
this.end = null;
}
function node_loc_t(start) {
this.start = start || token.startLoc || {line: 1, column: 0};
this.end = null;
if (sourceFile !== null) this.source = sourceFile;
}
function startNode() {
var node = new node_t(token.start);
if (options.locations)
node.loc = new node_loc_t();
if (options.directSourceFile)
node.sourceFile = options.directSourceFile;
return node;
}
function startNodeFrom(other) {
var node = new node_t(other.start);
if (options.locations)
node.loc = new node_loc_t(other.loc.start);
return node;
}
function finishNode(node, type) {
node.type = type;
node.end = lastEnd;
if (options.locations)
node.loc.end = lastEndLoc;
return node;
}
function getDummyLoc() {
if (options.locations) {
var loc = new node_loc_t();
loc.end = loc.start;
return loc;
}
};
function dummyIdent() {
var dummy = new node_t(token.start);
dummy.type = "Identifier";
dummy.end = token.start;
dummy.name = "✖";
dummy.loc = getDummyLoc();
return dummy;
}
function isDummy(node) { return node.name == "✖"; }
function eat(type) {
if (token.type === type) {
next();
return true;
}
}
function canInsertSemicolon() {
return (token.type === tt.eof || token.type === tt.braceR || newline.test(input.slice(lastEnd, token.start)));
}
function semicolon() {
eat(tt.semi);
}
function expect(type) {
if (eat(type)) return true;
if (lookAhead(1).type == type) {
next(); next();
return true;
}
if (lookAhead(2).type == type) {
next(); next(); next();
return true;
}
}
function checkLVal(expr) {
if (expr.type === "Identifier" || expr.type === "MemberExpression") return expr;
return dummyIdent();
}
function parseTopLevel() {
var node = startNode();
node.body = [];
while (token.type !== tt.eof) node.body.push(parseStatement());
return finishNode(node, "Program");
}
function parseStatement() {
var starttype = token.type, node = startNode();
switch (starttype) {
case tt._break: case tt._continue:
next();
var isBreak = starttype === tt._break;
node.label = token.type === tt.name ? parseIdent() : null;
semicolon();
return finishNode(node, isBreak ? "BreakStatement" : "ContinueStatement");
case tt._debugger:
next();
semicolon();
return finishNode(node, "DebuggerStatement");
case tt._do:
next();
node.body = parseStatement();
node.test = eat(tt._while) ? parseParenExpression() : dummyIdent();
semicolon();
return finishNode(node, "DoWhileStatement");
case tt._for:
next();
pushCx();
expect(tt.parenL);
if (token.type === tt.semi) return parseFor(node, null);
if (token.type === tt._var) {
var init = startNode();
next();
parseVar(init, true);
if (init.declarations.length === 1 && eat(tt._in))
return parseForIn(node, init);
return parseFor(node, init);
}
var init = parseExpression(false, true);
if (eat(tt._in)) {return parseForIn(node, checkLVal(init));}
return parseFor(node, init);
case tt._function:
next();
return parseFunction(node, true);
case tt._if:
next();
node.test = parseParenExpression();
node.consequent = parseStatement();
node.alternate = eat(tt._else) ? parseStatement() : null;
return finishNode(node, "IfStatement");
case tt._return:
next();
if (eat(tt.semi) || canInsertSemicolon()) node.argument = null;
else { node.argument = parseExpression(); semicolon(); }
return finishNode(node, "ReturnStatement");
case tt._switch:
var blockIndent = curIndent, line = curLineStart;
next();
node.discriminant = parseParenExpression();
node.cases = [];
pushCx();
expect(tt.braceL);
for (var cur; !closes(tt.braceR, blockIndent, line, true);) {
if (token.type === tt._case || token.type === tt._default) {
var isCase = token.type === tt._case;
if (cur) finishNode(cur, "SwitchCase");
node.cases.push(cur = startNode());
cur.consequent = [];
next();
if (isCase) cur.test = parseExpression();
else cur.test = null;
expect(tt.colon);
} else {
if (!cur) {
node.cases.push(cur = startNode());
cur.consequent = [];
cur.test = null;
}
cur.consequent.push(parseStatement());
}
}
if (cur) finishNode(cur, "SwitchCase");
popCx();
eat(tt.braceR);
return finishNode(node, "SwitchStatement");
case tt._throw:
next();
node.argument = parseExpression();
semicolon();
return finishNode(node, "ThrowStatement");
case tt._try:
next();
node.block = parseBlock();
node.handler = null;
if (token.type === tt._catch) {
var clause = startNode();
next();
expect(tt.parenL);
clause.param = parseIdent();
expect(tt.parenR);
clause.guard = null;
clause.body = parseBlock();
node.handler = finishNode(clause, "CatchClause");
}
node.finalizer = eat(tt._finally) ? parseBlock() : null;
if (!node.handler && !node.finalizer) return node.block;
return finishNode(node, "TryStatement");
case tt._var:
next();
node = parseVar(node);
semicolon();
return node;
case tt._while:
next();
node.test = parseParenExpression();
node.body = parseStatement();
return finishNode(node, "WhileStatement");
case tt._with:
next();
node.object = parseParenExpression();
node.body = parseStatement();
return finishNode(node, "WithStatement");
case tt.braceL:
return parseBlock();
case tt.semi:
next();
return finishNode(node, "EmptyStatement");
default:
var expr = parseExpression();
if (isDummy(expr)) {
next();
if (token.type === tt.eof) return finishNode(node, "EmptyStatement");
return parseStatement();
} else if (starttype === tt.name && expr.type === "Identifier" && eat(tt.colon)) {
node.body = parseStatement();
node.label = expr;
return finishNode(node, "LabeledStatement");
} else {
node.expression = expr;
semicolon();
return finishNode(node, "ExpressionStatement");
}
}
}
function parseBlock() {
var node = startNode();
pushCx();
expect(tt.braceL);
var blockIndent = curIndent, line = curLineStart;
node.body = [];
while (!closes(tt.braceR, blockIndent, line, true))
node.body.push(parseStatement());
popCx();
eat(tt.braceR);
return finishNode(node, "BlockStatement");
}
function parseFor(node, init) {
node.init = init;
node.test = node.update = null;
if (eat(tt.semi) && token.type !== tt.semi) node.test = parseExpression();
if (eat(tt.semi) && token.type !== tt.parenR) node.update = parseExpression();
popCx();
expect(tt.parenR);
node.body = parseStatement();
return finishNode(node, "ForStatement");
}
function parseForIn(node, init) {
node.left = init;
node.right = parseExpression();
popCx();
expect(tt.parenR);
node.body = parseStatement();
return finishNode(node, "ForInStatement");
}
function parseVar(node, noIn) {
node.declarations = [];
node.kind = "var";
while (token.type === tt.name) {
var decl = startNode();
decl.id = parseIdent();
decl.init = eat(tt.eq) ? parseExpression(true, noIn) : null;
node.declarations.push(finishNode(decl, "VariableDeclarator"));
if (!eat(tt.comma)) break;
}
if (!node.declarations.length) {
var decl = startNode();
decl.id = dummyIdent();
node.declarations.push(finishNode(decl, "VariableDeclarator"));
}
return finishNode(node, "VariableDeclaration");
}
function parseExpression(noComma, noIn) {
var expr = parseMaybeAssign(noIn);
if (!noComma && token.type === tt.comma) {
var node = startNodeFrom(expr);
node.expressions = [expr];
while (eat(tt.comma)) node.expressions.push(parseMaybeAssign(noIn));
return finishNode(node, "SequenceExpression");
}
return expr;
}
function parseParenExpression() {
pushCx();
expect(tt.parenL);
var val = parseExpression();
popCx();
expect(tt.parenR);
return val;
}
function parseMaybeAssign(noIn) {
var left = parseMaybeConditional(noIn);
if (token.type.isAssign) {
var node = startNodeFrom(left);
node.operator = token.value;
node.left = checkLVal(left);
next();
node.right = parseMaybeAssign(noIn);
return finishNode(node, "AssignmentExpression");
}
return left;
}
function parseMaybeConditional(noIn) {
var expr = parseExprOps(noIn);
if (eat(tt.question)) {
var node = startNodeFrom(expr);
node.test = expr;
node.consequent = parseExpression(true);
node.alternate = expect(tt.colon) ? parseExpression(true, noIn) : dummyIdent();
return finishNode(node, "ConditionalExpression");
}
return expr;
}
function parseExprOps(noIn) {
var indent = curIndent, line = curLineStart;
return parseExprOp(parseMaybeUnary(noIn), -1, noIn, indent, line);
}
function parseExprOp(left, minPrec, noIn, indent, line) {
if (curLineStart != line && curIndent < indent && tokenStartsLine()) return left;
var prec = token.type.binop;
if (prec != null && (!noIn || token.type !== tt._in)) {
if (prec > minPrec) {
var node = startNodeFrom(left);
node.left = left;
node.operator = token.value;
next();
if (curLineStart != line && curIndent < indent && tokenStartsLine())
node.right = dummyIdent();
else
node.right = parseExprOp(parseMaybeUnary(noIn), prec, noIn, indent, line);
var node = finishNode(node, /&&|\|\|/.test(node.operator) ? "LogicalExpression" : "BinaryExpression");
return parseExprOp(node, minPrec, noIn, indent, line);
}
}
return left;
}
function parseMaybeUnary(noIn) {
if (token.type.prefix) {
var node = startNode(), update = token.type.isUpdate;
node.operator = token.value;
node.prefix = true;
next();
node.argument = parseMaybeUnary(noIn);
if (update) node.argument = checkLVal(node.argument);
return finishNode(node, update ? "UpdateExpression" : "UnaryExpression");
}
var expr = parseExprSubscripts();
while (token.type.postfix && !canInsertSemicolon()) {
var node = startNodeFrom(expr);
node.operator = token.value;
node.prefix = false;
node.argument = checkLVal(expr);
next();
expr = finishNode(node, "UpdateExpression");
}
return expr;
}
function parseExprSubscripts() {
return parseSubscripts(parseExprAtom(), false, curIndent, curLineStart);
}
function parseSubscripts(base, noCalls, startIndent, line) {
for (;;) {
if (curLineStart != line && curIndent <= startIndent && tokenStartsLine()) {
if (token.type == tt.dot && curIndent == startIndent)
--startIndent;
else
return base;
}
if (eat(tt.dot)) {
var node = startNodeFrom(base);
node.object = base;
if (curLineStart != line && curIndent <= startIndent && tokenStartsLine())
node.property = dummyIdent();
else
node.property = parsePropertyName() || dummyIdent();
node.computed = false;
base = finishNode(node, "MemberExpression");
} else if (token.type == tt.bracketL) {
pushCx();
next();
var node = startNodeFrom(base);
node.object = base;
node.property = parseExpression();
node.computed = true;
popCx();
expect(tt.bracketR);
base = finishNode(node, "MemberExpression");
} else if (!noCalls && token.type == tt.parenL) {
pushCx();
var node = startNodeFrom(base);
node.callee = base;
node.arguments = parseExprList(tt.parenR);
base = finishNode(node, "CallExpression");
} else {
return base;
}
}
}
function parseExprAtom() {
switch (token.type) {
case tt._this:
var node = startNode();
next();
return finishNode(node, "ThisExpression");
case tt.name:
return parseIdent();
case tt.num: case tt.string: case tt.regexp:
var node = startNode();
node.value = token.value;
node.raw = input.slice(token.start, token.end);
next();
return finishNode(node, "Literal");
case tt._null: case tt._true: case tt._false:
var node = startNode();
node.value = token.type.atomValue;
node.raw = token.type.keyword;
next();
return finishNode(node, "Literal");
case tt.parenL:
var tokStart1 = token.start;
next();
var val = parseExpression();
val.start = tokStart1;
val.end = token.end;
expect(tt.parenR);
return val;
case tt.bracketL:
var node = startNode();
pushCx();
node.elements = parseExprList(tt.bracketR);
return finishNode(node, "ArrayExpression");
case tt.braceL:
return parseObj();
case tt._function:
var node = startNode();
next();
return parseFunction(node, false);
case tt._new:
return parseNew();
default:
return dummyIdent();
}
}
function parseNew() {
var node = startNode(), startIndent = curIndent, line = curLineStart;
next();
node.callee = parseSubscripts(parseExprAtom(), true, startIndent, line);
if (token.type == tt.parenL) {
pushCx();
node.arguments = parseExprList(tt.parenR);
} else {
node.arguments = [];
}
return finishNode(node, "NewExpression");
}
function parseObj() {
var node = startNode();
node.properties = [];
pushCx();
next();
var propIndent = curIndent, line = curLineStart;
while (!closes(tt.braceR, propIndent, line)) {
var name = parsePropertyName();
if (!name) { if (isDummy(parseExpression(true))) next(); eat(tt.comma); continue; }
var prop = {key: name}, isGetSet = false, kind;
if (eat(tt.colon)) {
prop.value = parseExpression(true);
kind = prop.kind = "init";
} else if (options.ecmaVersion >= 5 && prop.key.type === "Identifier" &&
(prop.key.name === "get" || prop.key.name === "set")) {
isGetSet = true;
kind = prop.kind = prop.key.name;
prop.key = parsePropertyName() || dummyIdent();
prop.value = parseFunction(startNode(), false);
} else {
next();
eat(tt.comma);
continue;
}
node.properties.push(prop);
eat(tt.comma);
}
popCx();
eat(tt.braceR);
return finishNode(node, "ObjectExpression");
}
function parsePropertyName() {
if (token.type === tt.num || token.type === tt.string) return parseExprAtom();
if (token.type === tt.name || token.type.keyword) return parseIdent();
}
function parseIdent() {
var node = startNode();
node.name = token.type === tt.name ? token.value : token.type.keyword;
next();
return finishNode(node, "Identifier");
}
function parseFunction(node, isStatement) {
if (token.type === tt.name) node.id = parseIdent();
else if (isStatement) node.id = dummyIdent();
else node.id = null;
node.params = [];
pushCx();
expect(tt.parenL);
while (token.type == tt.name) {
node.params.push(parseIdent());
eat(tt.comma);
}
popCx();
eat(tt.parenR);
node.body = parseBlock();
return finishNode(node, isStatement ? "FunctionDeclaration" : "FunctionExpression");
}
function parseExprList(close) {
var indent = curIndent, line = curLineStart, elts = [], continuedLine = nextLineStart;
next(); // Opening bracket
if (curLineStart > continuedLine) continuedLine = curLineStart;
while (!closes(close, indent + (curLineStart <= continuedLine ? 1 : 0), line)) {
var elt = parseExpression(true);
if (isDummy(elt)) {
if (closes(close, indent, line)) break;
next();
} else {
elts.push(elt);
}
while (eat(tt.comma)) {}
}
popCx();
eat(close);
return elts;
}
});