From: Erik Faye-Lund <kusmabite@googlemail.com>
Date: Mon, 14 Sep 2009 12:32:38 GMT
Subject: Re: [PATCH 2/2] remove NORETURN from function pointers
Message-ID: <40aa078e0909140532q693a7f9qc3d9b1d354cac356@mail.gmail.com>
In-Reply-To: <20090914120311.GA17172@sigill.intra.peff.net>

Compiling the following code gives a warning about unreachable code,
so it's clear that msvc doesn't simply ignore the directive. I'm not
saying that anyone suggested otherwise, I just wanted to know for
sure.

#include <stdio.h>
#include <stdlib.h>
void (*exit_fun)(int) = exit;
void __declspec(noreturn) die(void);
void die(void) { exit_fun(1); }
int main(void) { printf("hello!\n"); die(); printf("world!\n"); }

On Mon, Sep 14, 2009 at 2:03 PM, Jeff King <peff@peff.net> wrote:
> I think I am fine doing it either way. The NORETURN_PTR thing is a bit
> more elegant to me, but that is maybe just my gcc snobiness. We
> shouldn't have to change our code to accomodate MSVC's crappy noreturn
> handling. ;)

First of all, MSVC is not the only compiler that behaves this way. In
fact, GCC the only compiler I've found that behaves this way (but I
must admit, I only tested 4 different compilers, one of which (Comeau)
does not support noreturn at all AFAICT). That behavior might be
crappy, but it's not "MSVC's crappy noreturn handling" - it's
"non-GCC's crappy noreturn handling" :P

The arguments against each solution I see are these:
- abort() gives a run-time error instead of a compile-time warning, so
breakage is trickier to detect (on GCC, which seems to be the target
compiler for the vast majority of git-developers).
- NORETURN_PTR might be bit big of a hammer for a small problem, as it
"pollutes" the whole git source-tree instead of just usage.c.

Anyway, I don't care much what solution we pick. Either should work,
and if someone has strong preference, I'm OK with it.

-- 
Erik "kusma" Faye-Lund
kusmabite@gmail.com
(+47) 986 59 656