Re: [PATCH] Use multi-arch'd START_INFERIOR_TRAPS_EXPECTED on Alpha target

[Michael Snyder <msnyder at redhat dot com>]

Daniel Jacobowitz wrote:
> 
> On Wed, Apr 24, 2002 at 08:06:31PM -0400, Andrew Cagney wrote:
> > >The following puts STARTUP_WITH_SHELL
> >
> > Hmm, HP merge.  An intermediate version looked like:
> >
> >   /* If STARTUP_WITH_SHELL is set, GDB's "run"
> > !  * will attempts to start up the debugee under a shell.
> > !  * This is in order for argument-expansion to occur. E.g.,
> > !  * (gdb) run *
> > !  * The "*" gets expanded by the shell into a list of files.
> > !  * While this is a nice feature, it turns out to interact badly
> > !  * with some of the catch-fork/catch-exec features we have added.
> > !  * In particular, if the shell does any fork/exec's before
> > !  * the exec of the target program, that can confuse GDB.
> > !  * To disable this feature, set STARTUP_WITH_SHELL to 0.
> > !  * To enable this feature, set STARTUP_WITH_SHELL to 1.
> > !  * The catch-exec traps expected during start-up will
> > !  * be 1 if target is not started up with a shell, 2 if it is.
> > !  * - RT
> > !  */
> >   #define STARTUP_WITH_SHELL 1
> > - #define START_INFERIOR_TRAPS_EXPECTED (STARTUP_WITH_SHELL + 1)
> >
> > Does STARTUP_WITH_SHELL need to be multi-arched?
> >
> > I'm wondering if it would be better to make it a variable (``set
> > startup-with-shell <boolean>'').  Looking at its uses it appears that
> > fork-child.c:startup_inferior() would still work (if it did previously).
> 
> Silly question.... are there any (supported?  working?) uses for this
> besides globbing and backtick interpolation?  I think there aren't, and
> I think it would simplify GDB to just have a function which called
> glob() and invoked subshells for ``.  It's a little tricky, but not
> very.  We'd lose access to things like shell-specific globbing tricks,
> but I think that's a worthwhile price to pay.

I'm not so sure.  Sometimes getting the exact behavior of a specific
shell might be important.  Also, might this functionality be used
for piping and I/O redirection?