DEBUG trap and warn_create_global

DEBUG trap and warn_create_global

[Matthew Martin]

    f() { setopt local_options warn_create_global; :; }; trap : DEBUG; f

in zsh -f outputs

    f: scalar parameter ZSH_DEBUG_CMD created globally in function f

I would think ZSH_DEBUG_CMD is local to the trap execution. Otherwise
DEBUG traps can "break" warn_create_global clean functions.

- Matthew Martin

Re: DEBUG trap and warn_create_global

[Bart Schaefer]

On Sun, Nov 19, 2017 at 8:08 PM, Matthew Martin <phy1729@gmail.com> wrote:
>
> I would think ZSH_DEBUG_CMD is local to the trap execution. Otherwise
> DEBUG traps can "break" warn_create_global clean functions.

Hm.  Making it implicitly local would change the behavior with respect
to "unset after the trap."  I don't know how important that is.

However, it should be possible for it to be set without tripping the
warning, we just need to call assignsparam() instead of setsparam().

(Apologies if this gets wordwrapped or something, I don't have access
to my usual email client this week.)

diff --git a/Src/exec.c b/Src/exec.c
index fc6d02d..49da562 100644
--- a/Src/exec.c
+++ b/Src/exec.c
@@ -1319,7 +1319,9 @@ execlist(Estate state, int dont_change_job, int exiting)
            noerrexit = NOERREXIT_EXIT | NOERREXIT_RETURN;
            if (ltype & Z_SIMPLE) /* skip the line number */
                pc2++;
-           pm = setsparam("ZSH_DEBUG_CMD", getpermtext(state->prog, pc2, 0));
+           pm = assignsparam("ZSH_DEBUG_CMD",
+                              getpermtext(state->prog, pc2, 0),
+                              0);

            exiting = donetrap;
            ret = lastval;

Re: DEBUG trap and warn_create_global

[Matthew Martin]

On Mon, Nov 20, 2017 at 05:45:11PM -0800, Bart Schaefer wrote:
> On Sun, Nov 19, 2017 at 8:08 PM, Matthew Martin <phy1729@gmail.com> wrote:
> >
> > I would think ZSH_DEBUG_CMD is local to the trap execution. Otherwise
> > DEBUG traps can "break" warn_create_global clean functions.
> 
> Hm.  Making it implicitly local would change the behavior with respect
> to "unset after the trap."  I don't know how important that is.
> 
> However, it should be possible for it to be set without tripping the
> warning, we just need to call assignsparam() instead of setsparam().

This solves the example provided (and the original issue[1]). I have no
strong opinion on changing the documented behavior, so it should
probably be kept as is.

1: https://github.com/zsh-users/zsh-syntax-highlighting/issues/438