Re: RFC: glocal - automatically freeing memory when it goes out of scope

[Ben Pfaff <blp cs stanford edu>]

Mikkel Kamstrup Erlandsen <mikkel kamstrup canonical com> writes:

> On 05/29/2012 07:23 PM, Ben Pfaff wrote:
>> Mikkel Kamstrup Erlandsen<mikkel kamstrup canonical com>  writes:
>>
>>> I have been looking at gcc's "cleanup" attribute[1] that allows one to
>>> specify a callback that will be invoked when a variable goes out of
>>> scope. This allows one to play with automatically freeing resources.
>>
>> Is it possible to combine use of this GCC-specific attribute with
>> the concept in Doug Gwyn's "mostly-portable" alloca
>> implementation, so that you would end up with something that
>> works pretty much everywhere (but is more efficient with GCC)?
>>
>> Here's one copy of the Doug Gwyn alloca that just happened to be
>> on the top of the results of my web search:
>>          ftp://ftp.dante.de/tex-archive/fonts/utilities/ps2mf/alloca.c
>
> There is already g_alloca() and g_newa() for allocating on the stack.

I'm not suggesting an implementation of an alloca-like function
based on these ideas; as you say, glib already has alloca-like
functions.

I'm suggesting that one could use the idea behind the Doug Gwyn
portable alloca to implement something like, or at least related
to, the GCC "cleanup" attribute even when GCC is not the compiler
in use.  (However, the attribute syntax wouldn't work, and the
interface would otherwise need to be different.)