Open Bug 1486542 Opened Last year Updated Last year

Print some indicator to CACHEIR_LOGS when attachment doesn't happen


(Core :: JavaScript Engine: JIT, enhancement, P5)




Tracking Status
firefox63 --- affected


(Reporter: mgaudet, Unassigned)


(Blocks 1 open bug)


When developing Inline Caches with CacheIR, CACHEIR_LOGS is one of the debugging tools we have. 

This environment option prints to a file the log of all attempts to attache a CacheIR based inline cache. 

The log entries look like this: 


The log output as it is misses one important use case: Distinguishing easily cases where the CacheIR code was unable to attach an inline cache. In some circumstances this can be indicative of a need to add an inline cache. Right now, failure to attach an Inline Cache looks like this:

        "value":"105d89060 (shape: 105db7970)"
        "value":"105d95100 (shape: 105db0078)"

Exactly the same as the the successful case, except missing the "attached" key to indicate that the cache was attached. 

I propose we should instead have a key for all attempts, but simply put "attached":"false", to indicate failure. 

This would be very useful for cursory analytics with grep.
(This is perhaps less urgent now that has been updated. If we do decide to change this, will need to be patched to handle both old-and-new style logs)
Keywords: good-first-bug
Priority: P3 → P5
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