Date: Thu, 13 Dec 2012 13:10:43 +0000 From: David Chisnall <theraven@FreeBSD.org> To: Erik Cederstrand <erik@cederstrand.dk> Cc: "toolchain@freebsd.org" <toolchain@FreeBSD.org>, Pete chou <pete.chou@gmail.com> Subject: Re: Using non-standard linker Message-ID: <5880F938-A9EC-4B2D-8079-42504DFA87F9@FreeBSD.org> In-Reply-To: <089FCDB5-C0D2-4675-AB71-FD7089BFA031@cederstrand.dk> References: <089FCDB5-C0D2-4675-AB71-FD7089BFA031@cederstrand.dk>
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Hi Eric, The easiest way of doing this is to make /usr/bin/ld (in the host system and in the bootstrap) into a symbolic link that points to whatever the selected linker is. I had to do this when testing gold as well (we end up with ld-gold and ld-bfd and ld being a symlink to one of them). A better solution would be to teach clang about mclinker. I was pondering adding a linker selection flag, along the lines of the existing -stdlib= for selecting the C++ standard library, as you may want to pass different options to different linkers. David On 13 Dec 2012, at 12:36, Erik Cederstrand wrote: > Hi folks, > > I'm working with Pete Chou from MCLinker (actually, he's doing almost all the work) to get mclinker to survive a buildworld. The goal is to allow mclinker to be a drop-in replacement for GNU ld. > > My first suggestion was to just add LD=/usr/local/bin/mclinker to src.conf. But this only works when ld is invoked explicitly (and only when 'ld' is not hard-coded, of course). > > When ld is invoked internally by the compiler, Pete has tested that gcc(collect2) and clang do not respect the LD variable, but search for 'ld' in COMPILER_PATH and then PATH instead. Since mclinker is not part of the build process, it isn't found in COMPILER_PATH, and GNU ld is used instead. Instead, he can add an additional compiler search path via the "-B" flag, which seems to work. > > I'm worried that 'ld' is so hard-wired everywhere that it's impossible to specify another name. In that case, my suggestion would be to use build knobs, e.g. WITH_GNU_LD and WITH_MCLINKER_LD to install either GNU ld or mclinker as 'ld', but that wouldn't work unless mclinker is imported into base. > > What's the FreeBSD way of doing this? What do other toolchains do if they use a non-GNU ld linker? > > Thanks, > Erik > _______________________________________________ > freebsd-toolchain@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-toolchain > To unsubscribe, send any mail to "freebsd-toolchain-unsubscribe@freebsd.org"
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