On 2023-12-04 16:31, Martin Uecker wrote:
If (assuming from them being called lambdas) they are primarily for
small functions without side-effects then it's already a significantly
stronger specification than what we have right now with C nested
functions. That would end up enforcing what you demonstrate as the good
way to use nested functions.
The proposal we have seen for C23 (which was not accepted into
C23 mostly due to timing and lack of implementation experience)
were similar to C++'s lambdas and did not have any such restriction.
Oh well :/
If nested functions are eventually going to make it into the C standard
then effort is probably better spent in porting the C nested functions
to use descriptors instead of executable stacks or heaps.
I submitted a patch for this a long time ago which was based
on the code for Ada that uses a bit in the pointer to differentiate
between conventional pointers and descriptors.
I would now prefer an approach that uses a qualifier on the
function type to indicate that the static chain has to be
set. A pointer to such a qualified function would a descriptor
that consists of the address and the value for the static chain.
This would be useful for many things.
Ack, this probably becomes a gcc15 thing then, given that stage 1 has
closed. Are you planning to revive your work and repost?
Thanks,
Sid
