Assertion failure: hasScript(), at js/src/jsfun.h:432




3 years ago
2 years ago


(Reporter: bc, Unassigned)


(Blocks: 1 bug, {assertion, reproducible, testcase-wanted})

43 Branch
assertion, reproducible, testcase-wanted
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(2 attachments)



3 years ago
Created attachment 8703207 [details]

2. Assertion failure: hasScript(), at /builds/slave/m-cen-lx-d-0000000000000000000/build/src/js/src/jsfun.h:432

Beta/44, Aurora/45, Nightly/46 Linux, OSX, Windows

per bug 1233343 comment 9, this is a distinct bug.

Doesn't reproduce with a saved version.

Comment 2

3 years ago
I can not reproduce this with the url on today's Nightly build on Linux x86_64 nor with a build from 2015-12-30. There were 14 other urls where this assertion was seen with the latest instance being on 2016-02-22. While retesting these urls with today's builds automation reproduced the assertion. In particular, was reproducible and I can reproduce using a saved version though it may still have network accesses embedded. I'm attempting to reduce it a bit.
(In reply to Bob Clary [:bc:] from comment #2)
> I'm attempting to reduce it a bit.

Excellent, thanks. I'll wait for the reduced test case before investigating this.

Comment 4

3 years ago
jandem: I've been trying to get it reduced, but it appears that after a point the assertion is either mixed up with a crash or becomes random. I've been unsuccessful in reducing the main html page to less than a 1000 lines so far. I wouldn't wait for me to get this reduced as it may take some time. Running lithium locally to reduce the page means I can't effectively use my workstation and I'll have to stop for a bit.
I think I know what's going on. Let me try to write a reduced testcase...
Below is a testcase that fails in the JS shell with --no-threads

When Ion inlines a lambda, it can end up creating a CallObject with a lazy JSFunction as callee. The code in AssertDynamicScopeMatchesStaticScope, though, assumes a CallObject has a non-lazy callee...

It's tricky. We should probably audit all callers of callObj->callee() to make sure they handle the lazy callee case correctly. I can't think of another fix.

function f() {
    var arr = [];
    for (var i=0; i<1600; i++) {
        arr.push(function() {
            var x = 0;
            if (j === 1500)
                (function() { assertEq(x, 0); })();
    for (var j=0; j<arr.length; j++)
The right thing to do here is probably to rename CallObject::callee() to calleeMaybeLazy(), and then audit all callers.

I'll try to get to this either this week or next week.
Flags: needinfo?(jdemooij)
Shu, do you have any thoughts on comment 6 and comment 7? I'm not really happy with it but I can't think of a simpler fix.
Flags: needinfo?(jdemooij) → needinfo?(shu)

Comment 9

3 years ago
(In reply to Jan de Mooij [:jandem] from comment #8)
> Shu, do you have any thoughts on comment 6 and comment 7? I'm not really
> happy with it but I can't think of a simpler fix.

In the case of AssertDynamicScopeMatchesStaticScope, the laziness of the callee doesn't *actually* matter. It was the easiest way to get at a JSScript. Even in the crashing test case from comment 6, note that the script is actually already delazified: i.funScript() is the JSScript* we want, gotten from the canonical JSFunction. The crash is because the closure JSFunction Ion put into the CallObject hasn't tried to delazify yet. If it did it'd hit the cache on the LazyScript:

(gdb) p scope->as<js::CallObject>().callee().lazyScript()->maybeScript()
$12 = (JSScript *) 0x7ffff506c300
(gdb) p i.funScript()
$13 = (JSScript *) 0x7ffff506c300

The right fix in this case is perhaps adding a hasSameScript() predicate that can see through the "LazyScript cache" case, or perhaps have nonLazyScript() automatically resolve if a JSScript is already cached.
Flags: needinfo?(shu)
Flags: needinfo?(jdemooij)
Created attachment 8762798 [details]
new stack from bughunter

new url to reproduce is also that show the same assertion failure
Duplicate of this bug: 1284485
This was fixed in bug 1312491.
Last Resolved: 2 years ago
Flags: needinfo?(jdemooij)
Resolution: --- → DUPLICATE
Duplicate of bug: 1312491
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