1185168 - js_free should poison memory before it frees it, where possible

Status: RESOLVED WORKSFORME

(Core :: JavaScript Engine, enhancement)

Description

[Jeff Walden [:Waldo]]

I have a hacked-up version of this locally that consists of adding

#ifdef DEBUG
    size_t sz = malloc_usable_size(p);
    VALGRIND_DISABLE_ADDR_ERROR_REPORTING_IN_RANGE(p, sz);
    memset(p, 0x3D, sz);
    VALGRIND_ENABLE_ADDR_ERROR_REPORTING_IN_RANGE(p, sz);
#endif

to the start of js_free, with

#include <malloc.h>
#include <valgrind/memcheck.h>

added to the start of the file.  This is obviously not portable and would need cleanup along multiple axes to land.  :-)  But it would probably help expose some errors much more quickly.