Re: [PATCH] sim/m32c: fix memory leaks in opc2c

[Simon Marchi <simon.marchi@polymtl.ca>]

On 2021-04-05 12:23 p.m., Mike Frysinger wrote:> On 05 Apr 2021 10:58, Simon Marchi via Gdb-patches wrote:
>> Fix the leak in dump_lines by free-ing the elements of varnames.
> 
> i dislike stuffing a bunch of free's at the end of a program's lifetime just
> to satisfy a tool that is not normally used.  which isn't to say LSAN isn't
> useful, just that i think we should do better.

Why though?  Because it adds execution time where not necessary?

> in other codebases, i've done things like:
> #ifdef __SANITIZE_ADDRESS__
> # define ENABLE_CLEANUP_ONEXIT 1
> #else
> # define ENABLE_CLEANUP_ONEXIT 0
> #endif
> 
> then this could be written:
> 
> if (ENABLE_CLEANUP_ONEXIT) {
>   for (i = 0; i < vn; i++)
>     free (varnames[i]);
> }
> 
> wdyt ?  feel free to bikeshed the name.  not sure if there's prior art in
> the tree currently.

I find this complexity a bit unnecessary, versus just free-ing the
stuff.  But I don't really mind, we can do as you like, I just want to
my build to be fixed!

Note that the igen tool doesn't free anything, so it's next on the list
of things that break the -fsanizite=address build.  I started to update
it to free things, it's a bit tedious but it should be do-able.

Another option would be to change the Makefile to call igen with the
ASAN_OPTIONS=detect_leaks=0 environment variable.

Simon