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Re: Puzzling "implicit declaration" Warning

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Robbie Hatley <see.my.signature@for.my.contact.info> writes:
> On 2020-02-07 12:53 AM, Jorgen Grahn wrote:
>> Your variable names are really confusing!
>
> Well, since this program is not for corporate masters, I feel free
> to be as whimsical as I like. :-)

No, it's not for "corporate masters", it's for a bunch of C experts
you're asking for help.  Using obscure names like Beren and Luthien
rather than argc and argv doesn't help anyone.  Please write clear code.

[...]

>> If you read the exp10(3) man page, it says
>> 
>>    #define _GNU_SOURCE /* See feature_test_macros(7) */
>
> Well, not exactly. I get "No manual page for 'exp10'."
> Hmmm. I'm also getting "No manual page for 'exp'."
>
> Ok, turns out, in order to get those manual pages, I had to go into
> Cygwin setup and manually install a file called "C Function Documentation".

The package that provides the library man pages is called "cygwin-doc".
I suspect it's not installed by default out of concern for saving space.

> Seems to me that should be installed automatically with GCC, but oh well.
> Now I get:
>
> EXP10(3)                         Mathematical Functions (math.h)                         EXP10(3)
>
> NAME
>        exp10, exp10f - exponential, base 10
[...]
> PORTABILITY
>        exp10 and exp10f are GNU extensions.
>
> newlib                                      12/21/2019                                   EXP10(3)
>
>
> But it doesn't say anything about "#define _GNU_SOURCE".

I agree that it should.  I've sent email to the Cygwin mailing list
suggesting it.

https://cygwin.com/ml/cygwin/2020-02/msg00069.html

> Neither does "man gcc".

gcc is the compiler.  The compiler and library are separate components.
I wouldn't expect a compiler's documentation to discuss library
functions.

[...]

> But then, Cygwin breaks a number of conventions. GCC is expecting to
> see The Gnu Standard C Library. But that's NOT what Cygwin uses!
> It uses a (supposedly) equivalent library called "newlib", modified
> to behave in a Cygwin + GCC environment AS IF it was "The Gnu C
> Standard Library" (which it isn't). So any errors or omissions
> in creating the "Gnu-emulating modifed newlib" would result in
> puzzling issues. Perhaps this is one of those?

No, gcc (the GNU compiler collection) doesn't require glibc (the GNU C
library).  It can work with any conforming library implementation.  Some
implementations use Microsoft's C library.  Back when I used Solaris, it
worked with Sun's C library.

Typically gcc works with the "native" library for the platform.  There's
no particular reason that has to be glibc.  The folks who built Cygwin
made the perfectly valid decision to use newlib rather than glibc.

[...]

> And this problem has existed for YEARS, if not DECADES, and yet the Cygwin
> team has done NOTHING to fix it. "The framework to do this is not laid down
> SO FAR"??? What the devil??? SO FAR??? How many more decades are they going
> to wait??? Humankind will likely go extinct before these guys get their act
> together. Makes me want to seek a different programming platform. Perhaps
> Mingw or something like that.

Maybe you should ask for your money back.  Oh, wait ...

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips Healthcare
void Void(void) { Void(); } /* The recursive call of the void */

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Puzzling "implicit declaration" Warning Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-02-06 23:57 -0800
  Re: Puzzling "implicit declaration" Warning Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-02-07 08:53 +0000
    Re: Puzzling "implicit declaration" Warning Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-07 02:12 -0800
      Re: Puzzling "implicit declaration" Warning Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-02-08 01:53 -0800
        Re: Puzzling "implicit declaration" Warning Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-08 12:59 +0000
          Re: Puzzling "implicit declaration" Warning Manfred <noname@invalid.add> - 2020-02-08 17:21 +0100
            Re: Puzzling "implicit declaration" Warning Manfred <noname@invalid.add> - 2020-02-08 17:34 +0100
            Re: Puzzling "implicit declaration" Warning Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-08 14:37 -0800
        Re: Puzzling "implicit declaration" Warning scott@slp53.sl.home (Scott Lurndal) - 2020-02-08 18:39 +0000
    Re: Puzzling "implicit declaration" Warning Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-02-08 01:15 -0800
      Re: Puzzling "implicit declaration" Warning chad <cdalten@gmail.com> - 2020-02-08 05:05 -0800
      Re: Puzzling "implicit declaration" Warning Bart <bc@freeuk.com> - 2020-02-08 14:05 +0000
      Re: Puzzling "implicit declaration" Warning Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-08 14:35 -0800
        Re: Puzzling "implicit declaration" Warning Bart <bc@freeuk.com> - 2020-02-08 22:39 +0000
          Re: Puzzling "implicit declaration" Warning Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-08 15:30 -0800
          Re: Puzzling "implicit declaration" Warning David Brown <david.brown@hesbynett.no> - 2020-02-09 12:24 +0100
        Re: Puzzling "implicit declaration" Warning Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-02-09 23:42 -0800
          Re: Puzzling "implicit declaration" Warning chad <cdalten@gmail.com> - 2020-02-10 05:34 -0800
          Re: Puzzling "implicit declaration" Warning Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-10 16:12 +0000
          Re: Puzzling "implicit declaration" Warning Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-10 11:14 -0800
            Re: Puzzling "implicit declaration" Warning Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-02-11 07:06 +0000
            Re: puzzling enragement by innocuous variable names Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-09-10 19:47 -0700
              Re: puzzling enragement by innocuous variable names Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-09-10 20:28 -0700
              Re: puzzling enragement by innocuous variable names Peter 'Shaggy' Haywood <phaywood@alphalink.com.au> - 2020-09-13 14:57 +1000
                Re: puzzling enragement by innocuous variable names gazelle@shell.xmission.com (Kenny McCormack) - 2020-09-15 17:58 +0000
              Re: puzzling enragement by innocuous variable names Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2020-09-14 09:38 -0600
          Re: Puzzling "implicit declaration" Warning James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-11 00:21 -0500
  Re: Puzzling "implicit declaration" Warning Les Cargill <lcargill99@comcast.com> - 2020-02-08 17:00 -0600
    Re: Puzzling "implicit declaration" Warning Robbie Hatley <see.my.signature@for.my.contact.info> - 2020-02-09 22:50 -0800
      Re: Puzzling "implicit declaration" Warning Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-10 16:00 +0000
        Re: Puzzling "implicit declaration" Warning scott@slp53.sl.home (Scott Lurndal) - 2020-02-10 16:28 +0000
          Re: Puzzling "implicit declaration" Warning Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-10 16:42 +0000

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