765477 - IonMonkey: Assertion failure: v.isBoolean(), at jsobj.cpp:5876

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Christian Holler (:decoder)]

The following testcase asserts on ionmonkey revision de23a9fc29db (run with --ion -n -m --ion-eager):


function f(useArg2, arg2, expect) {
    var args = arguments;
    if (useArg2)
	args = arg2;
    assertEq(args.length, expect);
}
f(false, 0, 3);
f(false, 0, 3);

Comment 1

[Nicolas B. Pierron [:nbp]]

Attachment: Do not compiled type info mixed with argument object

Every time we check for an argument object, we ensure that this is the uniq flag.

Comment 2

[Jan de Mooij [:jandem]]

Comment on attachment 634332 [details] [diff] [review]
Do not compiled type info mixed with argument object

Review of attachment 634332 [details] [diff] [review]:
-----------------------------------------------------------------

This approach seems reasonable, r=me with nits addressed.

::: js/src/ion/IonBuilder.cpp
@@ +4054,5 @@
>          return jsop_getelem_string();
>  
> +    TypeCertainty isArguments = oracle->elementReadMagicArguments(script, pc);
> +    if (isArguments == UnSure)
> +        return abort("Type tags are messed-up.");

Nit: when reading the spew it would help to know the reason has to do with (lazy) arguments. So maybe something like "Not definitely accessing lazy arguments"?

::: js/src/ion/TypeOracle.cpp
@@ +556,5 @@
>  {
>      return getMIRType(script->analysis()->pushedTypes(pc, 0));
>  }
>  
> +TypeCertainty

Nit: a small comment here would be good, explaining why we have to do this.

@@ +562,5 @@
>  {
>      types::TypeSet *obj = script->analysis()->poppedTypes(pc, 0);
> +    if (obj->isMagicArguments(cx))
> +        return SureTrue;
> +    if (obj->hasAnyFlag(TYPE_FLAG_LAZYARGS))

Lazy args is not used if "obj" here could be "unknown" right?

::: js/src/ion/TypeOracle.h
@@ +74,5 @@
> +enum TypeCertainty {
> +    UnSure = 0,
> +    SureTrue,
> +    SureFalse
> +};

Nit: something like this seems slightly more readable: LazyArgumentsType { DefinitelyArguments, MaybeArguments, NotArguments };

Comment 3

[Christian Holler (:decoder)]

JSBugMon: The testcase found in this bug no longer reproduces (tried revision 3112408514c8).

Comment 4

[Nicolas B. Pierron [:nbp]]

https://hg.mozilla.org/projects/ionmonkey/rev/29aa7b886d50

Comment 5

[Christian Holler (:decoder)]

A testcase for this bug was automatically identified at js/src/jit-test/tests/ion/bug765477.js.