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From: jm36#@andrew.cmu.edu.UUCP
Newsgroups: comp.lang.c
Subject: Re: Use of #pragma
Message-ID: <IUXhaCy00V4FwZ00ZD@andrew.cmu.edu>
Date: Thu, 23-Apr-87 22:18:38 EST
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Posted: Thu Apr 23 22:18:38 1987
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Beak: Is

> From: LINNDR%VUENGVAX.BITNET@wiscvm.wisc.EDU
> Subject: Use of #pragma
> Date: 17 Apr 87 22:51:27 GMT
> 
> I could have
> !       <stuff 1>
> !       #pragma NO_OPTIMIZE
> !       <stuff that should not be optimized>
> !       #pragma OPTIMIZE
> !       <stuff 2)
> 

I certainly hope you don't try to feed a file like that through the
GNU C compiler anytime between 9AM and 5PM on weekdays.

From the documentation on the GNU preprocessor:
> The `#pragma' command is specified in the ANSI standard to have an
> arbitrary implementation-defined effect.  In the GNU C preprocessor,
> `#pragma' first attempts to run the game `rogue'; if that fails,
> it tries to run the game `hack'; if that fails, it tries to run
> GNU Emacs displaying the Tower of Hanoi; if that fails, it reports a
> fatal error.  In any case, preprocessing does not continue.

*ANY* C program which contains a "#pragma" is not portable.  One compiler
could interpret "#pragma OPTIMIZE" as meaning "Turn on the optimizer"
and another interpret it as meaning "Deposit the OP(code) called
'TIMIZE' in the object code."

				_.John