diff options
| -rw-r--r-- | js/src/frontend/Parser.cpp | 59 | ||||
| -rw-r--r-- | js/src/tests/ecma_2017/AsyncFunctions/await-in-arrow-parameters.js | 94 |
2 files changed, 128 insertions, 25 deletions
diff --git a/js/src/frontend/Parser.cpp b/js/src/frontend/Parser.cpp index 47e0f943d..0c279591f 100644 --- a/js/src/frontend/Parser.cpp +++ b/js/src/frontend/Parser.cpp @@ -3623,9 +3623,14 @@ Parser<ParseHandler>::functionFormalParametersAndBody(InHandling inHandling, FunctionBox* funbox = pc->functionBox(); RootedFunction fun(context, funbox->function()); - AutoAwaitIsKeyword<ParseHandler> awaitIsKeyword(this, funbox->isAsync()); - if (!functionArguments(yieldHandling, kind, pn)) - return false; + // See below for an explanation why arrow function parameters and arrow + // function bodies are parsed with different yield/await settings. + { + bool asyncOrArrowInAsync = funbox->isAsync() || (kind == Arrow && awaitIsKeyword()); + AutoAwaitIsKeyword<ParseHandler> awaitIsKeyword(this, asyncOrArrowInAsync); + if (!functionArguments(yieldHandling, kind, pn)) + return false; + } Maybe<ParseContext::VarScope> varScope; if (funbox->hasParameterExprs) { @@ -3689,32 +3694,36 @@ Parser<ParseHandler>::functionFormalParametersAndBody(InHandling inHandling, // |yield| in the parameters is either a name or keyword, depending on // whether the arrow function is enclosed in a generator function or not. // Whereas the |yield| in the function body is always parsed as a name. + // The same goes when parsing |await| in arrow functions. YieldHandling bodyYieldHandling = GetYieldHandling(pc->generatorKind(), pc->asyncKind()); - Node body = functionBody(inHandling, bodyYieldHandling, kind, bodyType); - if (!body) - return false; + Node body; + { + AutoAwaitIsKeyword<ParseHandler> awaitIsKeyword(this, funbox->isAsync()); + body = functionBody(inHandling, bodyYieldHandling, kind, bodyType); + if (!body) + return false; + } - if ((kind != Method && !IsConstructorKind(kind)) && fun->explicitName()) { + if ((kind == Statement || kind == Expression) && fun->explicitName()) { RootedPropertyName propertyName(context, fun->explicitName()->asPropertyName()); - // `await` cannot be checked at this point because of different context. - // It should already be checked before this point. - if (propertyName != context->names().await) { - YieldHandling nameYieldHandling; - if (kind == Expression) { - // Named lambda has binding inside it. - nameYieldHandling = bodyYieldHandling; - } else { - // Otherwise YieldHandling cannot be checked at this point - // because of different context. - // It should already be checked before this point. - nameYieldHandling = YieldIsName; - } + YieldHandling nameYieldHandling; + if (kind == Expression) { + // Named lambda has binding inside it. + nameYieldHandling = bodyYieldHandling; + } else { + // Otherwise YieldHandling cannot be checked at this point + // because of different context. + // It should already be checked before this point. + nameYieldHandling = YieldIsName; + } - if (!checkBindingIdentifier(propertyName, handler.getPosition(pn).begin, - nameYieldHandling)) - { - return false; - } + // We already use the correct await-handling at this point, therefore + // we don't need call AutoAwaitIsKeyword here. + + if (!checkBindingIdentifier(propertyName, handler.getPosition(pn).begin, + nameYieldHandling)) + { + return false; } } diff --git a/js/src/tests/ecma_2017/AsyncFunctions/await-in-arrow-parameters.js b/js/src/tests/ecma_2017/AsyncFunctions/await-in-arrow-parameters.js new file mode 100644 index 000000000..ebb4ea9da --- /dev/null +++ b/js/src/tests/ecma_2017/AsyncFunctions/await-in-arrow-parameters.js @@ -0,0 +1,94 @@ +var ieval = eval; +var AsyncFunction = async function(){}.constructor; + +var functionContext = { + Function: { + constructor: Function, + toSourceBody: code => `function f() { ${code} }`, + toSourceParameter: code => `function f(x = ${code}) { }`, + }, + AsyncFunction: { + constructor: AsyncFunction, + toSourceBody: code => `async function f() { ${code} }`, + toSourceParameter: code => `async function f(x = ${code}) { }`, + }, +}; + +function assertSyntaxError(kind, code) { + var {constructor, toSourceBody, toSourceParameter} = functionContext[kind]; + var body = toSourceBody(code); + var parameter = toSourceParameter(code); + + assertThrowsInstanceOf(() => { constructor(code); }, SyntaxError, constructor.name + ":" + code); + assertThrowsInstanceOf(() => { constructor(`x = ${code}`, ""); }, SyntaxError, constructor.name + ":" + code); + + assertThrowsInstanceOf(() => { eval(body); }, SyntaxError, "eval:" + body); + assertThrowsInstanceOf(() => { ieval(body); }, SyntaxError, "indirect eval:" + body); + + assertThrowsInstanceOf(() => { eval(parameter); }, SyntaxError, "eval:" + parameter); + assertThrowsInstanceOf(() => { ieval(parameter); }, SyntaxError, "indirect eval:" + parameter); +} + +function assertNoSyntaxError(kind, code) { + var {constructor, toSourceBody, toSourceParameter} = functionContext[kind]; + var body = toSourceBody(code); + var parameter = toSourceParameter(code); + + constructor(code); + constructor(`x = ${code}`, ""); + + eval(body); + ieval(body); + + eval(parameter); + ieval(parameter); +} + +function assertSyntaxErrorAsync(code) { + assertNoSyntaxError("Function", code); + assertSyntaxError("AsyncFunction", code); +} + +function assertSyntaxErrorBoth(code) { + assertSyntaxError("Function", code); + assertSyntaxError("AsyncFunction", code); +} + + +// Bug 1353691 +// |await| expression is invalid in arrow functions in async-context. +// |await/r/g| first parses as |AwaitExpression RegularExpressionLiteral|, when reparsing the +// arrow function, it is parsed as |IdentRef DIV IdentRef DIV IdentRef|. We need to ensure in this +// case, that we still treat |await| as a keyword and hence throw a SyntaxError. +assertSyntaxErrorAsync("(a = await/r/g) => {}"); +assertSyntaxErrorBoth("async(a = await/r/g) => {}"); + +// Also applies when nesting arrow functions. +assertSyntaxErrorAsync("(a = (b = await/r/g) => {}) => {}"); +assertSyntaxErrorBoth("async(a = (b = await/r/g) => {}) => {}"); +assertSyntaxErrorBoth("(a = async(b = await/r/g) => {}) => {}"); +assertSyntaxErrorBoth("async(a = async(b = await/r/g) => {}) => {}"); + + +// Bug 1355860 +// |await| cannot be used as rest-binding parameter in arrow functions in async-context. +assertSyntaxErrorAsync("(...await) => {}"); +assertSyntaxErrorBoth("async(...await) => {}"); + +assertSyntaxErrorAsync("(a, ...await) => {}"); +assertSyntaxErrorBoth("async(a, ...await) => {}"); + +// Also test nested arrow functions. +assertSyntaxErrorAsync("(a = (...await) => {}) => {}"); +assertSyntaxErrorBoth("(a = async(...await) => {}) => {}"); +assertSyntaxErrorBoth("async(a = (...await) => {}) => {}"); +assertSyntaxErrorBoth("async(a = async(...await) => {}) => {}"); + +assertSyntaxErrorAsync("(a = (b, ...await) => {}) => {}"); +assertSyntaxErrorBoth("(a = async(b, ...await) => {}) => {}"); +assertSyntaxErrorBoth("async(a = (b, ...await) => {}) => {}"); +assertSyntaxErrorBoth("async(a = async(b, ...await) => {}) => {}"); + + +if (typeof reportCompare === "function") + reportCompare(true, true); |