Re: how to make a macro work as a single line if stmt without braces

From	Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups	comp.lang.c
Subject	Re: how to make a macro work as a single line if stmt without braces
Date	2024-09-24 07:36 -0700
Organization	A noiseless patient Spider
Message-ID	<86ikul6ruw.fsf@linuxsc.com> (permalink)
References	(2 earlier) <vcn6m8$1n1vu$1@dont-email.me> <vcp0rq$26p7b$1@dont-email.me> <20240922080605.59@kylheku.com> <vcpeo0$28shf$1@dont-email.me> <20240922192726.000061fc@yahoo.com>

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Michael S <already5chosen@yahoo.com> writes:

> On Sun, 22 Sep 2024 16:56:47 +0100
> Bart <bc@freeuk.com> wrote:
>
>> On 22/09/2024 16:11, Kaz Kylheku wrote:
>>
>>> On 2024-09-22, David Brown <david.brown@hesbynett.no> wrote:
>>>
>>>> I am not suggesting overuse of braces.  I am suggesting /good/ use
>>>> of them.
>>>>
>>>> <https://www.synopsys.com/blogs/software-security/
>>>>     understanding-apple-goto-fail-vulnerability-2.html>
>>>>
>>>> That's perhaps the most famous example of the havoc caused by
>>>> omitting useful braces.
>>>>
>>>> Consistency and clarity is important.  So is maintainability.
>>>> Suppose, for example, you want to add a line "attempts++;"
>>>> alongside the "ok++;" line.  When the braces are there, the change
>>>> is exactly that - add the new line you want.  Without the original
>>>> braces, you are now making changes to the structural syntax of the
>>>> code as well when you add in original braces - or you are making a
>>>> mistake in the code.
>>>
>>> My super advanced text editor from the future isn't letting me do
>>> that:
>>>
>>>    if (failed)
>>>      WARN("failed because...");
>>>    else
>>>      ok++;
>>>    attempts++; // automatic deindent
>>>
>>> When I add a line after ok++, it deindents it to be at the same
>>> indentation level as the if, before letting me type any content
>>> into it.
>>>
>>> OK, I lied about the super advanced from the future.  It's just
>>> Vim.
>>>
>>> Also GCC has been able to diagnose misleading indentation for some
>>> years now.
>>>
>>> Between those two, there is nothing to worry about;  just
>>> concentrate on whether it looks prettier without the braces or
>>> with.
>>
>> So, everyone has to write code exactly to the C standard.
>>
>> But when it comes to more practical matters, it's OK to depend on
>> the arbitrary characteristics and abilities of whichever one of
>> 1001 different text editors we happen to be using.
>>
>> Or we have to use a specific compiler with a specific set of
>> options.
>>
>>> Also GCC has been able to diagnose misleading indentation for some
>>> years now.
>>
>> How many years was that out of the last 52?  How exactly do you
>> turn it on?  Since -Wall -Wpedantic -Wextra doesn't report it.
>
> My gcc warns just fine.
>
> void bar(int);
> int foo(int x) {
>   if (x)
>     bar(x);
>     x -= 1;
>   return x;
> }
>
> gcc -c -Wall foo.c
>
> foo.c:  In function 'foo':
> foo.c:3:3: warning: this 'if' clause does not guard...
> [-Wmisleading-indentation] 3 |   if (x)
>       |   ^~
> foo.c:5:5: note: ...this statement, but the latter is misleadingly
> indented as if it were guarded by the 'if'
>     5 |     x -= 1;
>       |     ^
>
>
>> It is a failure in the design of the language.  You can't really
>> depend on ad hoc features of the tools you use to create and
>> compile source code.
>>
>> At least guidelines can be used such as always using braces, then
>> errors can occur less often.
>>
>> (I've been bitten by this endless times when trying to add
>> debugging statements to existing code.  If that code consistently
>> used braces, then it wouldn't happen.)
>
> I wonder why I was not bitten by that more than, may be, 5 times
> in 30+ years.  Probably, I am doing something wrong.

My long-standing habit is to write this

   if(x)  bar(x);

or this

   if(x){
      bar(x);
   }

but never this

   if(x)
      bar(x);

The reason for this habit is that many years ago I got bitten by
trying to add a line in the last case.  The habit subsequently
adopted has proven very effective at eliminating such errors.

The idea of changing the language to always require braces is
unnecessary and wasteful (besides being a non-starter for purely
practical reasons).

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how to make a macro work as a single line if stmt without braces Mark Summerfield <mark@qtrac.eu> - 2024-09-21 07:35 +0000
  Re: how to make a macro work as a single line if stmt without braces Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-09-21 08:10 +0000
  Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-21 10:47 +0200
    Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-21 12:27 -0700
      Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-21 21:11 +0100
      Re: how to make a macro work as a single line if stmt without braces Opus <ifonly@youknew.org> - 2024-09-21 22:39 +0200
      Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-21 14:54 -0700
        Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-21 20:05 -0700
          Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-21 21:33 -0700
          Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-22 14:15 +0200
          Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-27 03:38 -0700
      Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-22 13:59 +0200
        Re: how to make a macro work as a single line if stmt without braces Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-22 15:11 +0000
          Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-22 16:56 +0100
            Re: how to make a macro work as a single line if stmt without braces Michael S <already5chosen@yahoo.com> - 2024-09-22 19:27 +0300
              Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-22 17:47 +0100
              Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-24 07:36 -0700
                Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-24 07:52 -0700
                Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-24 17:24 +0200
                Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-24 17:22 +0100
                Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-24 12:28 -0700
                Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-27 01:43 -0700
                Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-24 17:35 +0100
                Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-24 12:30 -0700
                Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-24 20:42 +0100
                Re: how to make a macro work as a single line if stmt without braces Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-24 19:59 +0000
                Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-24 21:12 +0100
                Re: how to make a macro work as a single line if stmt without braces Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-24 22:36 +0000
            Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-22 13:39 -0700
              Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-23 08:16 +0200
                Re: how to make a macro work as a single line if stmt without braces Richard Harnden <richard.nospam@gmail.invalid> - 2024-09-23 08:06 +0100
                Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-23 11:14 +0200
                Re: how to make a macro work as a single line if stmt without braces Richard Harnden <richard.nospam@gmail.invalid> - 2024-09-23 11:37 +0100
                Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-23 14:22 +0200
          Modern text editor - 'bout time someone paid attention to keeping the thread title relevant!!! (Was: how to make a macro work as a single line if stmt without braces) gazelle@shell.xmission.com (Kenny McCormack) - 2024-09-22 16:03 +0000
          Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-22 18:03 +0200
      Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-28 05:02 -0700
        Re: how to make a macro work as a single line if stmt without braces Michael S <already5chosen@yahoo.com> - 2024-09-28 20:30 +0300
          Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-28 21:53 -0700
            Re: how to make a macro work as a single line if stmt without braces Michael S <already5chosen@yahoo.com> - 2024-09-29 12:48 +0300
              Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-29 19:18 -0700
              Re: how to make a macro work as a single line if stmt without braces Alan Mackenzie <acm@muc.de> - 2024-09-30 15:05 +0000
        Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-28 21:02 -0700
          Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-28 22:47 -0700
            Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-29 07:41 -0700
              Re: how to make a macro work as a single line if stmt without braces Michael S <already5chosen@yahoo.com> - 2024-09-29 18:04 +0300
              Re: how to make a macro work as a single line if stmt without braces scott@slp53.sl.home (Scott Lurndal) - 2024-09-29 18:30 +0000
              Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-29 16:39 -0700
                Re: how to make a macro work as a single line if stmt without braces Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-30 02:29 +0000
                Re: how to make a macro work as a single line if stmt without braces Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-09-30 11:26 +0200
              Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-29 18:39 -0700
              Re: how to make a macro work as a single line if stmt without braces Kaz Kylheku <643-408-1753@kylheku.com> - 2024-09-30 02:03 +0000
              Re: how to make a macro work as a single line if stmt without braces David Brown <david.brown@hesbynett.no> - 2024-09-30 13:17 +0200
  Re: how to make a macro work as a single line if stmt without braces Bart <bc@freeuk.com> - 2024-09-21 10:13 +0100
    Re: how to make a macro work as a single line if stmt without braces Mark Summerfield <mark@qtrac.eu> - 2024-09-21 09:53 +0000
  Re: how to make a macro work as a single line if stmt without braces Ike Naar <ike@sdf.org> - 2024-09-21 09:15 +0000
    Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-21 14:44 -0700
  Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-21 06:07 -0700
    Re: how to make a macro work as a single line if stmt without braces Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-09-21 15:55 -0700
  Re: how to make a macro work as a single line if stmt without braces Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-09-21 12:17 -0700
  Re: how to make a macro work as a single line if stmt without braces Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> - 2024-09-21 21:18 +0000
    Re: how to make a macro work as a single line if stmt without braces Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-09-24 06:18 -0700

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