Re: nested functions

[Bruno Haible]

[Not sure this is the right forum. Maybe stackoverflow.com would be a better
 place to discuss this.]

Tim Rühsen wrote:
> BTW, nested functions are pretty nice to use.
> 
> But I still wonder why
> 
>  - nested functions need an executable stack (why does the code have to
> be run on the stack ?)

Because in most ABIs, a function pointer is a pointer to the first instruction.
The notable exceptions are:
  - PowerPC and PowerPC64 with AIX ABI,
  - ia64
  - hppa, hppa64.
See 
https://git.savannah.gnu.org/gitweb/?p=libffcall.git;a=blob;f=porting-tools/abis/function-pointer.txt

>  - there are no efforts to standardize either nested functions or blocks
> (clang has 'blocks' instead of nested functions) or both.

As far as I understand, this [1] would be a profound change of the C language.
Possibly people feel that C shouldn't evolve in an uncontrolled and crazy way
like C++ does...

Bruno

[1] https://en.wikipedia.org/wiki/Blocks_(C_language_extension)