zsh-workers
 help / color / mirror / code / Atom feed
From: Peter Stephenson <p.stephenson@samsung.com>
To: <zsh-workers@zsh.org>
Subject: Re: [PATCH 2/2] Fix two C nits
Date: Tue, 19 Jun 2018 15:13:19 +0100	[thread overview]
Message-ID: <20180619141321eucas1p194af5292bb4f5030e0536c500ef9c6c5~5lTSLcvNm0521405214eucas1p1I@eucas1p1.samsung.com> (raw)
In-Reply-To: <20180619134629.GA15318@zira.vinc17.org>

On Tue, 19 Jun 2018 15:46:29 +0200
Vincent Lefevre <vincent@vinc17.net> wrote:
> On 2018-06-18 10:22:41 +0100, Peter Stephenson wrote:
> > On Sat, 16 Jun 2018 01:04:27 +0000
> > Eitan Adler <lists@eitanadler.com> wrote:  
> > > - avoid returning from a function that will never return
> > >
> > > diff --git a/Src/exec.c b/Src/exec.c
> > > index d44527841..b36bcef64 100644
> > > --- a/Src/exec.c
> > > +++ b/Src/exec.c
> > > @@ -4954,7 +4954,6 @@ getpipe(char *cmd, int nullexec)
> > >      execode(prog, 0, 1, out ? "outsubst" : "insubst");
> > >      cmdpop();
> > >      _exit(lastval);
> > > -    return 0;
> > >  }  
>
> The _exit function is non-standard.

That means from the basic C point of view it's not safe simply to remove
the return.  We are not in the game of guessing what the compiler knows.

As the code's uambiguously correct as it is, and the compiler is
perfectly at liberty to optimise out the return if it knows the function
won't return, it can stay as it is.

Anything we *can* detect about the compiler / configuration is
fair game for improvement, however...

pws


  reply	other threads:[~2018-06-19 14:13 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20180616021439epcas4p327f4346b40d9e10d94ce055058fe0d71@epcas4p3.samsung.com>
2018-06-16  1:04 ` Eitan Adler
2018-06-18  9:22   ` Peter Stephenson
2018-06-19  5:31     ` Eitan Adler
2018-06-19 13:46     ` Vincent Lefevre
2018-06-19 14:13       ` Peter Stephenson [this message]
2018-06-19 14:38         ` Vincent Lefevre
2018-06-19 15:59           ` Peter Stephenson

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='20180619141321eucas1p194af5292bb4f5030e0536c500ef9c6c5~5lTSLcvNm0521405214eucas1p1I@eucas1p1.samsung.com' \
    --to=p.stephenson@samsung.com \
    --cc=zsh-workers@zsh.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.vuxu.org/mirror/zsh/

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).