Date: Mon, 22 Sep 2014 09:09:34 -0600 From: Will Andrews <will@firepipe.net> To: Bruce Evans <brde@optusnet.com.au> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, "src-committers@FreeBSD.org" <src-committers@freebsd.org>, Julian Elischer <julian@freebsd.org> Subject: Re: svn commit: r271771 - in head: bin/csh etc/mail lib/libc usr.bin/grep usr.sbin/mtree Message-ID: <CADBaqmh97wuxL4w_duTsFN1-EAp7PeVGKqEcvWcMZJjymHsfUw@mail.gmail.com> In-Reply-To: <20140920172111.Q4941@besplex.bde.org> References: <201409181441.s8IEfvR1075223@svn.freebsd.org> <541D2356.8040403@freebsd.org> <20140920172111.Q4941@besplex.bde.org>
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On Sat, Sep 20, 2014 at 1:38 AM, Bruce Evans <brde@optusnet.com.au> wrote: > The log message is confused. Source files are not being overwritten. > They are being copied to object directories using cp. Then if they > are read-only in the source directory, they are read-only in the object > directory, even if they are copied without -p so as to clobber their > timestamps (their mode is still preserved). Then if the source file's > mtime is changed, either by actually changing the file or just by > clobbering its mtime, the copy in the object directory becomes out of > date. Then the cp to make it up to date fails because it is read-only. Yes, this is the more correct way of explaining the issue. Thanks. > Many makefiles avoid this problem by using cat instead of cp to copy > the files. I prefer using cp -p. The above fixes the problem for > a makefile that uses cp (without -p) by adding -f. This causes the file > to be unlinked before a new copy is made. If the object directory is > in the source tree (most likely since it is the source directory) and > the source files are read-only, then this would often fail because the > source directory is also read-only, but then it can't reasonably be > an object directory. The problem with 'cp -p' is that it doesn't work either. Try it (twice) with a read-only file -- I get EPERM when I try the second time. cp -p also doesn't work with NFS targets if the file happens to have flags. In the case of .CURDIR == .OBJDIR, the file would satisfy the dependency and thus not be overwritten with itself. In any case, this is about read-only *files* anyway, not read-only directories, since as you point out, the latter are unusable as object directories. --Will.
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