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From: Alexander Holler <holler@ahsoftware.de>
To: Austin S Hemmelgarn <ahferroin7@gmail.com>,
	Peter Zijlstra <peterz@infradead.org>
Cc: "Borislav Petkov" <bp@alien8.de>,
	"Måns Rullgård" <mans@mansr.com>,
	"Steven Rostedt" <rostedt@goodmis.org>,
	"Christopher Barry" <christopher.r.barry@gmail.com>,
	linux-kernel@vger.kernel.org
Subject: Re: OT: Open letter to the Linux World
Date: Thu, 04 Sep 2014 20:11:11 +0200	[thread overview]
Message-ID: <5408AB3F.4010803@ahsoftware.de> (raw)
In-Reply-To: <5408A84C.1090806@gmail.com>

Am 04.09.2014 19:58, schrieb Austin S Hemmelgarn:
> On 2014-09-04 13:29, Alexander Holler wrote:
>> Am 04.09.2014 16:36, schrieb Austin S Hemmelgarn:
>>> On 2014-09-04 06:16, Alexander Holler wrote:
>>>>
>>>> It's a myth that C++ ends up in bigger code than C. At least in my
>>>> experience. Especially when the latest additions to C++ are in effect
>>>> (like the move-semantics in C++11 I like quiet a lot and which you get
>>>> almost for free (by changing nothing) when you use the STL). Thread
>>>> support is now also standardized (in C++11), quiet nice to use.
>>
>>> Assuming you are writing in a standalone environment (no standard
>>> libraries), then yes, your code will usually be about the same size
>>> (unless you go way overboard with the object-oriented stuff); but the
>>> runtime is larger in almost all non-standalone environments, and there
>>> are some cases that code does end up larger in C++.  A lot of 'Clean C'
>>> (stuff written so that it compiles correctly as C, C++ and Objective C)
>>> that I have seen seems to end up larger (by about 4-6%) when built as
>>> C++ (although it usually does much worse as Objective C).
>>
>> There are always corner cases and I never would use some "Clean C" code
>> to compare sizes of C and C++. There is a whole lot of stuff you just
>> can't, shouldn't or wouldn't do when using C instead of C++.
>>
>> And just throwing in some numbers without any explanation about features
>> (like exceptions), optimizations and so on you've enabled for the tests
>> you used to get those numbers, doesn't work. ;)
>>
>> I can't really comment on what you mean with "standalone environment" or
>> "non-standalone environment", as I don't know what you mean with that.
>> But if several programms share e.g. the stuff which is in libstdc++.
>> you'll get a lot of size back when compared with C-only programms where
>> everyone invents the wheel again and again.
> By standalone environment, I mean no libraries, no libc[++], no external
> dependencies, and in the case of a lot of kernel programming, no
> built-ins.  A OS kernel HAS to be written like that, and it's easier to
> do that in C than C++.  I doubt that you have ever looked at any source
> code for Windows drivers, but Windows is written in C++, and they still
> are just as mind-numbingly insane as some of the poorly maintained,
> vendor originated Linux drivers.

I've seen drivers for Windows and for OS2/2 and DOS and FreeBSD and ...

But throwing the ball back, did you know that all Arduino SW is in C++? ;)

> Not all C is like the Linux kernel, and in fact, if you use Linux,
> probably more than half of your user-space programs were written in C.
> They use dynamic linking just like C++ programs (but often with less
> complex symbol mangling).

This thread isn't about the kernel, but some userspace program which 
does quiet a lot and which wants to do even more. I've just used one 
example I did in the kernel space to explain what I miss when I'm using 
or having to use C instead of C++.

I do understand why the Linux kernel is (still) in C and don't want to 
start a discussion about that.

Regards,

Alexander Holler

  reply	other threads:[~2014-09-04 18:11 UTC|newest]

Thread overview: 41+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-12 19:38 OT: Open letter to the Linux World Christopher Barry
2014-08-12 20:21 ` Steven Rostedt
2014-08-12 20:44   ` Borislav Petkov
2014-08-12 22:07   ` Måns Rullgård
2014-08-13  8:27     ` Peter Zijlstra
2014-08-13  9:00       ` Borislav Petkov
2014-08-18 18:15         ` Alexander Holler
2014-09-04  7:54           ` Peter Zijlstra
2014-09-04 10:16             ` Alexander Holler
2014-09-04 14:36               ` Austin S Hemmelgarn
2014-09-04 17:29                 ` Alexander Holler
2014-09-04 17:58                   ` Austin S Hemmelgarn
2014-09-04 18:11                     ` Alexander Holler [this message]
2014-09-04 18:27           ` Rogelio Serrano
2014-09-04 18:33             ` Alexander Holler
2014-09-04 19:18               ` Rob Landley
2014-09-05  6:31                 ` Alexander Holler
2014-09-06 20:01                   ` Alexander Holler
2014-09-06 23:44                     ` Lennart Sorensen
2014-09-07  1:42                       ` Alexander Holler
2014-08-13  9:24       ` Måns Rullgård
2014-08-13  9:31         ` Peter Zijlstra
2014-08-13  9:37           ` Måns Rullgård
2014-08-13  9:37       ` Martin Steigerwald
2014-08-13  9:52         ` Peter Zijlstra
2014-08-13  9:59           ` Martin Steigerwald
2014-08-13  9:54         ` Peter Zijlstra
2014-08-13  9:57         ` Måns Rullgård
2014-08-13 10:21           ` Martin Steigerwald
2014-08-13 20:19       ` William Pitcock
2014-08-14  1:08 ` Robert Hancock
2014-08-15 18:41 ` Jaswinder Singh
2015-04-08 13:12 ` Denys Vlasenko
2015-04-09  0:37   ` Rob Landley
2015-04-09 18:18     ` Denys Vlasenko
2015-04-10 12:40     ` Rogelio M. Serrano Jr.
2015-04-10 21:20     ` Aaro Koskinen
2015-04-11  1:08       ` Rob Landley
     [not found] <E1XHxA6-0000ar-2a@feisty.vs19.net>
2014-08-15  8:59 ` Vlad Glagolev
2014-08-15 14:04   ` Gene Heskett
2014-08-16 21:10   ` Rob Landley

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