Function dlrealloc

system/lib/dlmalloc.c:5279–5326

#if !ONLY_MSPACES

void* dlrealloc(void* oldmem, size_t bytes) {
    void* mem = 0;
    if (oldmem == 0) {
        mem = dlmalloc(bytes);
    }
    else if (bytes >= MAX_REQUEST) {
        MALLOC_FAILURE_ACTION;
    }
#ifdef REALLOC_ZERO_BYTES_FREES
    else if (bytes == 0) {
        dlfree(oldmem);
    }
#endif /* REALLOC_ZERO_BYTES_FREES */
    else {
        size_t nb = request2size(bytes);
        mchunkptr oldp = mem2chunk(oldmem);
#if ! FOOTERS
        mstate m = gm;
#else /* FOOTERS */
        mstate m = get_mstate_for(oldp);
        if (!ok_magic(m)) {
            USAGE_ERROR_ACTION(m, oldmem);
            return 0;
        }
#endif /* FOOTERS */
        if (!PREACTION(m)) {
            mchunkptr newp = try_realloc_chunk(m, oldp, nb, 1);
            POSTACTION(m);
            if (newp != 0) {
                check_inuse_chunk(m, newp);
                mem = chunk2mem(newp);
#if __EMSCRIPTEN__
                /* XXX Emscripten Tracing API. */
                emscripten_trace_record_reallocation(oldmem, mem, bytes);
#endif
            }
            else {
                mem = internal_malloc(m, bytes);
                if (mem != 0) {
                    size_t oc = chunksize(oldp) - overhead_for(oldp);
                    memcpy(mem, oldmem, (oc < bytes)? oc : bytes);
                    internal_free(m, oldmem);
                }
            }
        }
    }
    return mem;
}

void* dlrealloc_in_place(void* oldmem, size_t bytes) {
    void* mem = 0;