Bug 212886 – Redeclaration of a function* inside a block definition

• Status: NEW
• Component: JavaScriptCore

[Jefferson Junior]

Hi everyone,
I found a case of redeclaration of a generator function inside a block definition.

version: 262693
OS: Linux Ubuntu 19.10 x64

steps to reproduce:

{ 
    function* f() { yield 1 }
    function f() { print(2) }
}
f()
Actual results:
2

Expected results:
SyntaxError: Identifier 'f' has already been declared

V8, SpiderMonkey works as expected.

cinfuzz

[Radar WebKit Bug Importer]

<rdar://problem/64188468>

[Rick Waldron]

This bug affects every combination with a lexical declaration in a block, in non-strict mode code (strict mode code is correct). 


{ async function f() {} async function f() {} }

{ async function f() {} async function* f() {} }

{ async function* f() {} async function f() {} }

{ async function* f() {} async function* f() {} }

{ async function f() {} class f {} }

{ async function* f() {} class f {} }

{ async function f() {} const f = 0 }

{ async function* f() {} const f = 0 }

{ async function f() {} function f() {} }

{ async function* f() {} function f() {} }

{ async function f() {} function* f() {} }

{ async function* f() {} function* f() {} }

{ async function f() {} let f }

{ async function* f() {} let f }

{ async function f() {} var f }

{ async function* f() {} var f }

{ class f {} async function f() {} }

{ class f {} async function* f() {} }

{ class f {} function f() {} }

{ class f {} function* f() {} }

{ const f = 0; async function f() {} }

{ const f = 0; async function* f() {} }

{ const f = 0; function f() {} }

{ const f = 0; function* f() {} }

{ function f() {} async function f() {} }

{ function f() {} async function* f() {} }

{ function f() {} class f {} }

{ function f() {} const f = 0 }

{ function f() {} function* f() {} }

{ function f() {} let f }

{ function f() {} var f }

{ function* f() {} async function f() {} }

{ function* f() {} async function* f() {} }

{ function* f() {} class f {} }

{ function* f() {} const f = 0 }

{ function* f() {} function f() {} }

{ function* f() {} function* f() {} }

{ function* f() {} let f }

{ function* f() {} var f }

{ async function f() {}; { var f; } }

{ async function* f() {}; { var f; } }

{ function f() {} { var f; } }

{ function* f() {}; { var f; } }

{ let f; async function f() {} }

{ let f; async function* f() {} }

{ let f; function f() {} }

{ let f; function* f() {} }

{ var f; async function f() {} }

{ var f; async function* f() {} }

{ var f; function f() {} }

{ var f; function* f() {} }

{ async function f() {}; var f; }

{ async function* f() {}; var f; }

{ function f() {}; var f; }

{ function* f() {}; var f; }




These fail in both strict mode code and non-strict mode code: 


{ { var f; } async function f() {}; }

{ { var f; } async function* f() {}; }

{ { var f; } function f() {} }

{ { var f; } function* f() {}; }

{ var f; async function f() {} }

{ var f; async function* f() {} }

{ var f; function f() {} }

{ var f; function* f() {} }



In all cases show here, a SyntaxError exception should be thrown at parse time.

[Rick Waldron]

Fixing this issue would bring JSC into 100% interop with V8 and SpiderMonkey