585750 - JM: Fix PIC Resetting

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Sean Stangl [:sstangl]]

Attachment: Patch v1

PIC resetting is not well-tested, leading to problems when gczeal(2) is inserted by the fuzzer. One such testcase (bug 585540) revealed a problem with resetting that only segfaulted on x86_64 but was wrong on x86.

There were two problems:
- GetPropCompiler::reset() was attempting to patch the inline path's type guard jump, even if it didn't exist;
- GetElemCompiler had no reset method, instead hijacking GetPropCompiler's, which used invalid values.

The attached patch respects pic->hasTypeGuard() and implements GetElemCompiler::reset().

Comment 1

[Sean Stangl [:sstangl]]

http://hg.mozilla.org/users/danderson_mozilla.com/moo/rev/9faa11693873

Comment 2

[David Mandelin [:dmandelin]]

Good work. I was just working on the same thing, discovered via running trace-tests with gczeal on. This was most likely causing unpredictable Mochitest failures as well.