[Bug fortran/29240] optional argument for signal intrinsic not supported

["dfranke at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #6 from dfranke at gcc dot gnu dot org  2007-05-29 18:13 -------
I am currently looking at the implementation of signal, so adding this may be
not too much effort. Some questions/remarks:

> The third argument "flag" is an integer that plays the role of SIG_DFL 
> in the C library version of signal(). [...] for example, it says that 
> when flag=-1, control is passed to the user's signal handler function
> "ctrlco" when signal number "signum" is encountered.  If flag=0, the 
> user's signal handler function is ignored and the default action is 
> taken instead.

 (1) There is no 3-argument version of signal(2) in glibc-2.[56]?! 
 (2) You are aware of the differnt ways to invoke the SIGNAL function? You can
_either_ set a handler function or use handler=1 (SIG_IGN) or handler=0
(SIG_DFL):

  INTEGER, PARAMETER :: SIG_DFL = 0, SIG_IGN = 1
  status = signal(number, handler)     ! install a signal handler
  status = signal(number, SIG_DFL)     ! restore default handler
  status = signal(number, SIG_IGN)     ! ignore signal

This won't compile your code out of the box, but gives the functionality you
are asking for (as I understand it). Introducing a third argument seems to be
redundant. 

FX, you confirmed this enhancement: is do-as-the-others-do really good enough a
reason to implement this?


-- 

dfranke at gcc dot gnu dot org changed:

           What    |Removed                     |Added
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                 CC|                            |dfranke at gcc dot gnu dot
                   |                            |org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29240