From: Peter Stephenson <p.w.stephenson@ntlworld.com>
To: zsh-workers@zsh.org
Subject: Re: using trap function to cleanup and exit?
Date: Tue, 19 Apr 2022 19:55:24 +0100 [thread overview]
Message-ID: <477f4f5b54230f5896896112b31ef45e7c495e72.camel@ntlworld.com> (raw)
In-Reply-To: <220ac31e9aa5262cc93fbd7c37da76154a80d09b.camel@ntlworld.com>
On Tue, 2022-04-19 at 19:42 +0100, Peter Stephenson wrote:
> On Fri, 2022-04-15 at 15:27 -0700, Bart Schaefer wrote:
> > On Thu, Apr 14, 2022 at 2:29 PM Bart Schaefer <schaefer@brasslantern.com> wrote:
> > >
> > > [I] would prefer that another set of eyes review
> > > the code change.
> >
> > To expand on that a bit ...
> >
> > The BIN_RETURN branch checks that (trap_return == -2) which is a
> > pretty specific number. exec.c says:
> > * This is only active if we are inside a trap, else its value
> > * is irrelevant. It is initialised to -1 for a function trap and
> > * -2 for a non-function trap and if negative is decremented as
> > * we go deeper into functions and incremented as we come back up.
> > * The value is used to decide if an explicit "return" should cause
> > * a return from the caller of the trap; it does this by setting
> > * trap_return to a status (i.e. a non-negative value).
> >
> > My interpretation is that, since we are in an explicit "exit" rather
> > than an explicit "return", we don't really care how trap_return is
> > set; we're going to force the caller to return, period.
>
> I just got back and looked, and it's hard to see how this could make
> anything worse.
Very minor comment (entirely cosmetic): it would probably be good
practice to check trap_state != TRAP_STATE_INACTIVE rather than just
trap_state. Does the following look reasonable? In fact, it might
be even more logical just to check for PRIMED.
With hindsight, "primed" isn't a great choice of word, it doesn't
indicate what state we are actually at in trap processing, but without
following this all through in more detail I wouldn't like to suggest
another. (And the resulting
TRAP_STATE_WE_DID_THIS_BUT_WE_HAVENT_YET_DONE_THIS_BECAUSE_WERE_WAITING_FOR_THIS
might not be any better...)
pws
diff --git a/Src/builtin.c b/Src/builtin.c
index b93466ba5..88d69e070 100644
--- a/Src/builtin.c
+++ b/Src/builtin.c
@@ -5720,7 +5720,11 @@ bin_break(char *name, char **argv, UNUSED(Options ops), int func)
* a bad job.
*/
if (stopmsg || (zexit(0, ZEXIT_DEFERRED), !stopmsg)) {
- if (trap_state)
+ /*
+ * If the trap is primed but we've hit an explicit exit,
+ * we should skip any further handling and bail out now.
+ */
+ if (trap_state != TRAP_STATE_INACTIVE)
trap_state = TRAP_STATE_FORCE_RETURN;
retflag = 1;
breaks = loops;
next prev parent reply other threads:[~2022-04-19 18:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-10 15:46 Greg Klanderman
2022-04-10 15:57 ` Peter Stephenson
2022-04-10 16:12 ` Greg Klanderman
2022-04-10 16:30 ` Greg Klanderman
2022-04-10 18:15 ` Lawrence Velázquez
2022-04-14 5:13 ` Greg Klanderman
2022-04-10 20:49 ` Bart Schaefer
2022-04-10 20:55 ` Bart Schaefer
2022-04-14 5:57 ` Greg Klanderman
2022-04-14 21:29 ` Bart Schaefer
2022-04-14 23:35 ` Bart Schaefer
2022-04-17 17:08 ` Daniel Shahaf
2022-04-15 22:27 ` Bart Schaefer
2022-04-19 18:42 ` Peter Stephenson
2022-04-19 18:55 ` Peter Stephenson [this message]
2022-04-19 21:22 ` Bart Schaefer
2022-04-20 8:16 ` Peter Stephenson
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