RFC: obstack_mark() and obstack_release()

[Dimitrios Apostolou]

Hi Roland,

On Fri, 8 Jun 2012, Roland McGrath wrote:

> Can you explain the motivation?
>

sure: it was the case of (indirect) recursion, which happened within the 
loop that I was growing an object, so after returning from the recursion 
another iteration of the array could grow it even larger. Context is at

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53525

See in the last patch the expand_arg() function, which grows an object but 
also calls cpp_get_token_1() which itself might end up again in 
expand_arg() growing another temporary object. Let me know if I was not 
clear.


Thanks,
Dimitris