Date: Wed, 20 Jan 2010 16:45:51 +1100 (EST) From: Bruce Evans <brde@optusnet.com.au> To: Ed Schouten <ed@FreeBSD.org> Cc: svn-src-head@FreeBSD.org, svn-src-all@FreeBSD.org, src-committers@FreeBSD.org Subject: Re: svn commit: r202661 - head/lib/libc/gen Message-ID: <20100120163243.A68431@delplex.bde.org> In-Reply-To: <201001192307.o0JN7CKu034318@svn.freebsd.org> References: <201001192307.o0JN7CKu034318@svn.freebsd.org>
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On Tue, 19 Jan 2010, Ed Schouten wrote: > Author: ed > Date: Tue Jan 19 23:07:12 2010 > New Revision: 202661 > URL: http://svn.freebsd.org/changeset/base/202661 > > Log: > Revert r202447 by re-exposing the old uname(3) function. > > It makes hardly any sense to expose a symbol which should only be > provided for binary compatibility, but it seems we don't have a lot of > choice here. There are many autoconf scripts out there that try to > create a binary that links against the old symbol to see whether > uname(3) is present. These scripts fail to detect uname(3) now. > > It should be noted that the behaviour we implement is not against the > standards: Of course it is against standards. This is implicit for most functions, and the part of the standard that you quoted says it explicitly for uname(): > | The following shall be declared as a function and may also be defined ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^ > | as a macro: > | > | int uname(struct utsname *); Examples of use of the function when it is also defined as a macro: /* Avoid any macro definition of the function when calling it. */ (uname)(namep); /* Take the address of uname in an obfuscated way. */ foo(uname); /* Take the address of uname in an unobfuscated way. */ foo(&uname); /* Try to debug uname. */ (gdb) b uname Function "uname" not defined... (gdb) #^#^^^@* someone defined uname as a macro :-(. #undef uname /* Now uname is not defined as a macro, though it may have been. */ uname(namep); Bruce
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