TRY_CATCH()

[Andrew Cagney <ac131313 at redhat dot com>]

Hello,

The exceptions rewrite opens up a key possibility.  It's now possible to 
define a macro such that:

  struct args
  {
    ...
  };

  do_func (void *data)
  {
    struct args *args = data;
    ... do stuff ...;
  }

  func (...)
  {
    struct args args;
    args... = ...;
    struct exception e = catch_exception (..., func, &args, ...)
    switch (e.reason)
      ...
  }

can be replaced with the more compact:

  func (...)
  {
    volatile struct exception e;
    TRY_CATCH (e)
      {
        ... do stuff ...;
      }
    switch (e.reason)
      ...
  }

Yes I know macros a bad, m'kay.  However, this offers a simple way to 
rewrite the code using something more like a real programming languages 
try/catch.

Andrew

PS: I recall this being proposed years ago, but the mechanism proposed 
at the time had a more cumbersom syntax, from memory something like:

  TRY_BEGIN
    ... do stuff ...
  TRY_END;

comments?
Andrew