952295 - Fix an exact rooting hazard in CompileLazyFunction

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Terrence Cole [:terrence]]

Attachment: hazard_CompileLazyFunction-v0.diff

This is a real hazard as |lazy| is live across this gc. I've added the ability to have a Rooted<LazyScript*> and made it a handle.

Function '_ZN2js8frontend19CompileLazyFunctionEP9JSContextPNS_10LazyScriptEPKDsm|uint8 js::frontend::CompileLazyFunction(JSContext*, js::LazyScript*, uint16*, uint64)' has unrooted 'lazy' of type 'js::LazyScript*' live across GC call '_ZN2js8frontend13NameFunctionsEPNS_16ExclusiveContextEPNS0_9ParseNodeE|uint8 js::frontend::NameFunctions(js::ExclusiveContext*, js::frontend::ParseNode*)' at js/src/frontend/BytecodeCompiler.cpp:437
    js/src/frontend/BytecodeCompiler.cpp:433: Call(40,41, pn := parser.standaloneLazyFunction(__temp_23*,staticLevel*,__temp_24*,__temp_25*))
    js/src/frontend/BytecodeCompiler.cpp:434: Assume(41,46, null(pn*), false)
    js/src/frontend/BytecodeCompiler.cpp:437: Call(46,47, __temp_26 := NameFunctions(cx*.field:0,pn*))
    js/src/frontend/BytecodeCompiler.cpp:437: Assume(47,52, !__temp_26*, false)
    js/src/frontend/BytecodeCompiler.cpp:440: Call(52,53, __temp_27 := lazy*.enclosingScope())

Comment 1

[Steve Fink [:sfink] [:s:]]

Comment on attachment 8350335 [details] [diff] [review]
hazard_CompileLazyFunction-v0.diff

Review of attachment 8350335 [details] [diff] [review]:
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Oops, sorry for the delay. I had already looked at this, but it looks like I forgot to publish the r+.

Comment 2

[Terrence Cole [:terrence]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/5ca9c43ed284

Comment 3

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/5ca9c43ed284