Re: [RFA] Fix leak in forward-search

[Philippe Waroquiers <philippe.waroquiers@skynet.be>]

On Thu, 2018-11-29 at 15:42 +0000, Pedro Alves wrote:
> 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 for the review, I have pushed this version, but I have added in
my todo list the better fix + add a test : I found no explicit
functional test for this command + my limited time on GDB development is also
shared with analysing the remaining several hundreds tests having a definite
leak :).

Philippe