Re: warning: trigraph ... ignored - again

From: H. Peter Anvin (
Date: Fri Jun 16 2000 - 18:56:00 EST

Tim Hollebeek wrote:
> H. Peter Anvin writes ...
> >
> > It doesn't change the meaning of the program, because I have, very
> > explicitly, turned the abominations called trigraphs *OFF*. I don't
> > care one bit if it never compiles with a non-gcc compiler ever again,
> > because it has 2^n other gcc extensions to the language.
> <rant>
> If you aren't a linux kernel maintainer (and heavens knows there are
> plenty of other programs compiled with gcc, even if the linux kernel
> folks fail to realize that), you care about portability.
> Personally, I love being warned that what I've written might behave
> differently on 64-bit pointer environments, or other compilers, or
> ... whatever.

So why does gcc have a whole slew of extensions to the C language at
all? Noone in their right mind would ever want to use them, except for
-fhead-stuck-in-ground-believing-only-linux-matters people, no?

> Today I was writing a parser that rewrites C programs to guarantee
> certain important properties (among them, security!). It works
> wonderfully on many OSs. It does not work on Linux. Why? Because
> the Linux headers are absolutely riddled with completely unnecessary
> uses of gcc extensions.
> I really hate how Linux kernel and libc maintainers insist on
> "embracing and extending" the ISO C standard.
> </rant>

Most of these gcc extensions predates Linux by quite a bit. Oh, and for
your reference, too: I use gcc for a bunch of other projects, a fair
number of them could never be written portably because they operate at
far too low of a level. The ready availability and the powerful inline
asm features of gcc has made it my compiler of choice for these


P.S. Oh, by the way: I personally don't know of a single C compiler
which doesn't support trigraph-free operation. If there were any, I
would use a preprocessor to do anti-trigraphing on them before giving
them to that compiler.

<> at work, <> in private!
"Unix gives you enough rope to shoot yourself in the foot."

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