Date: Wed, 13 Feb 2013 04:02:42 +0000 From: "b.f." <bf1783@googlemail.com> To: Steve Kargl <sgk@troutmask.apl.washington.edu> Cc: freebsd-current@freebsd.org, Anton Shterenlikht <mexas@bristol.ac.uk> Subject: Re: 7+ days of dogfood Message-ID: <CAGFTUwPR8o=wn9ogCLkwVmsFmeGGs6akjaM51GSxHO8k2%2Bfmfg@mail.gmail.com> In-Reply-To: <20130213033933.GA89757@troutmask.apl.washington.edu> References: <CAGFTUwN3Rrq-S_7uwZ%2B5MkbG1O7k59JK%2Bv-2qFoQ%2BofkMjyUEg@mail.gmail.com> <20130213014734.GA89321@troutmask.apl.washington.edu> <CAGFTUwOvZ3CcZzYaxgDr6yb6AoDAPvqvs3vqh0_EjS6jFx-kbA@mail.gmail.com> <20130213033933.GA89757@troutmask.apl.washington.edu>
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On 2/13/13, Steve Kargl <sgk@troutmask.apl.washington.edu> wrote: > On Wed, Feb 13, 2013 at 02:15:08AM +0000, b.f. wrote: >> On 2/13/13, Steve Kargl <sgk@troutmask.apl.washington.edu> wrote: >> > On Wed, Feb 13, 2013 at 12:18:29AM +0000, b.f. wrote: >> >> ># cat /etc/make.conf|grep FFLAGS >> >> >FFLAGS = -O2 -pipe -march=native -mtune=native >> >> >> >> Please do _not_ assign flags unconditionally in make.conf. >> > >> > FFLAGS is for compiling Fortran. I'm one of the people who >> > has spent years working/patching gfortran. I think I might >> > have a better understanding of what options to use with >> > gfortran than most people. >> > >> >> I know you have, but you are giving advice that is liable to be abused >> by those who are less experienced. The flags you are adding are not >> the problem -- it's the way that you are adding them -- specifically, >> the assignment in the first line of your snippet, if it's applied >> unconditionally. You should either be appending all of them, or >> assigning them conditionally, so that they are sure to be assigned >> only once, or -- preferably -- using another makefile that can't be >> re-read multiple times during a build (ports/Mk/bsd.port.mk >> automatically includes several makefiles that can be used for this >> purpose, if you are building a port). You have been lucky not to trip >> over this: every couple of months for the last several years I have >> had to debug errors reported by users that arise from this problem. It >> is more common with CFLAGS and CXXFLAGS but it can happen with FFLAGS, >> too. > > Try 'find /usr/ports -name Makefile -maxdepth 3 | xargs grep FFLAGS' > Then go read about the options chosen by the various port maintainers. > I specifically set FFLAGS to avoid the questionable options set in > the ports. If -malign-double appears in a port, it should probably > be marked as broken. If a port uses -fdefault-real-8, it should probably > be marked as broken. If a port uses -ffast-math, it may have issues that > are extremely difficult to debug. Okay, so you are doing this advisedly for some specific subset of ports, and have the knowledge to debug problems that may arise -- others don't. Undoubtedly some of these additions are suboptimal or unnecessary -- and I'm sure we'd welcome patches or suggestions to improve them -- but there are also important additions like the rpath flags in $PORTSDIR/Mk/bsd.gcc.mk or mangling and PIC directives. And not all of the additions are in the ports tree makefiles or patchfiles: many software distribution makefiles also make additions that can be clobbered by abusing make.conf. b.
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