From owner-freebsd-hackers  Thu Jun  4 21:22:28 1998
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To: freebsd-hackers@FreeBSD.ORG
Subject: style(9) error?
Date: Thu, 04 Jun 1998 16:22:22 -0500
From: "Chris Csanady" <cc@swing.ca.sandia.gov>
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I would like to make use of a feature that style tells me I can use, but
gcc tells me I can not..

>From style(9):

     es, it makes it easier to read.  If the macro encapsulates a compound
     statement, enclose it in a ``do'' loop, so that it can safely be used in
     ``if'' statements.  Any final statement-terminating semicolon should be
     supplied by the macro invocation rather than the macro, to make parsing
     easier for pretty-printers and editors.

     #define MACRO(x, y) do {                                                \
             variable = (x) + (y);                                           \
             (y) += 2;                                                       \
     } while(0)

As far as I can tell, it is impossible to put a do loop in a if statement,
or anything else.  Is this correct?  I always thought that blocks evaluated
to their last statements, but it seems not..

Chris Csanady


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