[Mesa-dev] [PATCH] glsl: Fix memory leak in builtin_builder::_image_prototype.

[Kenneth Graunke]

On Thursday, October 02, 2014 11:28:35 AM Ian Romanick wrote:
> Since this is Curro's code, I'm CC'ing me.
> 
> On 10/01/2014 03:12 AM, Iago Toral Quiroga wrote:
> > in_var calls the ir_variable constructor, which dups the variable name.
> > ---
> >  src/glsl/builtin_functions.cpp | 8 +++++---
> >  1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/src/glsl/builtin_functions.cpp b/src/glsl/builtin_functions.cpp
> > index 5a024cb..7d61fcc 100644
> > --- a/src/glsl/builtin_functions.cpp
> > +++ b/src/glsl/builtin_functions.cpp
> > @@ -4465,9 +4465,11 @@ builtin_builder::_image_prototype(const glsl_type *image_type,
> >        sig->parameters.push_tail(in_var(glsl_type::int_type, "sample"));
> >  
> >     /* Data arguments. */
> > -   for (unsigned i = 0; i < num_arguments; ++i)
> > -      sig->parameters.push_tail(in_var(data_type,
> > -                                       ralloc_asprintf(NULL, "arg%d", i)));
> > +   for (unsigned i = 0; i < num_arguments; ++i) {
> > +      char *arg_name = ralloc_asprintf(NULL, "arg%d", i);
> > +      sig->parameters.push_tail(in_var(data_type, arg_name));
> > +      ralloc_free(arg_name);
> > +   }
> 
> Using a NULL memory context is generally bad... precisely because it
> often leads to memory leaks.
> 
> There are a couple ways to fix this.  Since all of the image functions
> have a limited number of parameters, we could either:
> 
>  - Have a fixed size buffer that we snprintf to.
> 
>  - Have a table of all the parameter names.
> 
>  - Since this is the function prototype, I don't think we need names for
> the parameters at all.  Just pass NULL?

Does anything even use the names?  I don't think anything does...at which point, why not just call them all "arg" and be done with it?

--Ken
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.freedesktop.org/archives/mesa-dev/attachments/20141003/d65a1ecf/attachment.sig>