Re: [PATCH] compat/mingw.[ch]: Change return type of exec functions to int

From: Jeff King <peff@peff.net>
Date: Apr 6, 2012, 00:24 UTC
Message-ID: <20120406002454.GB14224@sigill.intra.peff.net>
In-Reply-To: <20120405223408.GA13910@burratino>

On Thu, Apr 05, 2012 at 05:34:36PM -0500, Jonathan Nieder wrote:

Show 18 quoted lines

> > --- a/run-command.c
> > +++ b/run-command.c
> > @@ -117,8 +117,11 @@ static int exists_in_PATH(const char *file)
> >  
> >  int sane_execvp(const char *file, char * const argv[])
> >  {
> > -	if (!execvp(file, argv))
> > -		return 0;
> > +	/*
> > +	 * No need to check the return value; if it returns at all, an error
> > +	 * occurred.
> > +	 */
> > +	execvp(file, argv);
> >  
> 
> I'd rather have the "return 0" then.  Such a comment that focuses on C
> library details rather than providing additional information for
> understanding the sane_execvp function is distracting.

I think both (attempt to) document the same thing: that if we get past execvp, we know are in error-checking mode. Which is not explicitly said anywhere. So maybe:

diff --git a/run-command.c b/run-command.c
index 7123436..e6ece79 100644
--- a/run-command.c
+++ b/run-command.c
@@ -117,10 +117,12 @@ static int exists_in_PATH(const char *file)
 
 int sane_execvp(const char *file, char * const argv[])
 {
-	if (!execvp(file, argv))
-		return 0;
+	execvp(file, argv);
 
 	/*
+	 * If we are still running, we know an error occurred; let's try to
+	 * diagnose it more specifically.
+	 *
 	 * When a command can't be found because one of the directories
 	 * listed in $PATH is unsearchable, execvp reports EACCES, but
 	 * careful usability testing (read: analysis of occasional bug