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Re: [RFA] Fix leak in forward-search


On 11/27/2018 11:33 PM, Philippe Waroquiers wrote:
> Valgrind reports the below leak.
> Fix the leak by using xrealloc, even for the first allocation,
> as buf is static.
> 
> ==29158== 5,888 bytes in 23 blocks are definitely lost in loss record 3,028 of 3,149
> ==29158==    at 0x4C2BE2D: malloc (vg_replace_malloc.c:299)
> ==29158==    by 0x41B557: xmalloc (common-utils.c:44)
> ==29158==    by 0x60B7D9: forward_search_command(char const*, int) (source.c:1563)
> ==29158==    by 0x40BA68: cmd_func(cmd_list_element*, char const*, int) (cli-decode.c:1888)
> ==29158==    by 0x665300: execute_command(char const*, int) (top.c:630)
> ...
> 
> gdb/ChangeLog
> 2018-11-28  Philippe Waroquiers  <philippe.waroquiers@skynet.be>
> 
> 	* source.c (forward_search_command): Fix leak by using
> 	xrealloc even for the first allocation in the loop, as buf
> 	is static.

At first sight it would seem like 'buf' was made static to avoid 
allocating a growing buffer for each command invocation.

But then, if that were the case, then you'd want 'cursize' to be
static as well.

The patch is OK, but I think that replacing 'buf' and all that
manual buffer growing with a non-static gdb::def_vector<char> defined
outside the outer loop would be even better.

Thanks,
Pedro Alves


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