Re: Memory leak in bison 1.35

[Ignasi Villagrasa]

Thanks for answering at first, Tim.

Yes. I use flex also.

I've built the corresponding files for bison and flex, and have an 
application that runs yyparse many times, using the corresponding rules.

In fact, the application runs sql sentences continously. I notice that 
memory leak is growing continuosly every time yyparse is called. It 
seems to grow in 4Kb  chunks. I've only tested it using Windows task 
administrator, without any other checker, but it always fails when 
calling yyparse. If I comment this function, the memory leak dissapears. 
Obviously I don't have the desired program behaviour, but I can isolate 
the problem.

Does flex allocate a buffer every time yyparse is called, or it does 
only the first time  ?

Thanks in advance, Ignasi Villagrasa.


Tim Van Holder wrote:

> On Tue, 2002-08-27 at 12:34, Ignasi Villagrasa wrote:
>
> > Hi everyone,
> >
> > I'm using bison version 1.35 that comes with cygwin package for Windows 
> > enviroments.
> >
> > I detect a memory leak in generated C code. Function yyparse loses 
> > periodically 4K chunks memory.
> >
> > Because of the unclear generated code, I'd like to know if there's a 
> > known solution for this problem before getting into the source code.
>
> Are you also using flex?
> At startup, flex allocates a buffer that is never freed; it's not really
> a memory leak (flex merely has no point at which it can free the buffer
> normally, so it relies on the normal 'at end' cleanup), but will be
> reported as such by many memory checkers.
> It allocates chunks of 16k tho, not 4k.