je_malloc_usable_size vs. malloc_usable_size - unknown symbol for macos

[aarlt]

Disclaimer: I'm not a rust developer.

It looks like that https://github.com/servo/heapsize/blob/master/src/lib.rs#L44 seem to create linking problems - at least on macos 10.13.6. It looks like that you rename the symbol to be je_malloc_usable_size for macos, ios and android systems. At least for macos - after installing jemalloc with brew install jemalloc - the jemalloc library that will be installed doesn't define a symbol named je_malloc_usable_size - but there is a symbol malloc_usable_size defined here.

The issue originally came up here: openethereum/parity-ethereum#9167.

[jdm]

Maybe the solution here is to add a non-default cargo feature named unprefixed_malloc that would inhibit this line. This would allow projects to override the defaults for whatever configuration they require.

[aarlt]

@jdm thank you for your reply