From owner-svn-src-head@freebsd.org Mon Dec 14 21:23:16 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 3C2824C3E82; Mon, 14 Dec 2020 21:23:16 +0000 (UTC) (envelope-from rlibby@gmail.com) Received: from mail-qk1-f194.google.com (mail-qk1-f194.google.com [209.85.222.194]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4CvvWS0x0Wz3rBS; Mon, 14 Dec 2020 21:23:15 +0000 (UTC) (envelope-from rlibby@gmail.com) Received: by mail-qk1-f194.google.com with SMTP id u5so4146395qkf.0; Mon, 14 Dec 2020 13:23:15 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yl5VqMWvzxm++ywW19/h3XpPRRq0c35eY7vDU2bDT6Y=; b=Ri3n5xGvcE+mbv2JwKGwJG+dmSHliu44M7gNFdu5rQcqb0jEWLsU0ZaiPpVrO0Hvqh NiDgIyY1cl10OEV6WfUJtY7CQCHM6MO9d5s598egovO0/8gPN9UL3hqQQaiB1N/3cVn1 u27IEZL+x0L/Be80+f5zx5GhSAWUeJFYguF+do00khHID4ugHn4lDndkNYFUiohdkxt9 3Mf+qIkoQInsh10+ivL0i2/ZSTe2HBmppOMi+y0mrff9xRypFdxWqbr+Py42DYUxlPw8 Te9E0m3+n28qTIxiSaJxniViScAo2yDtXfguO2XGLHkPyo4ykYlx6dm7RcN4TmK1htqQ 9SfQ== X-Gm-Message-State: AOAM532+DKo2rKyiGj5T5+gxDVzRnTi4MwBUOHDTqXhFyCKI5ZPOzGpN 57uBKWAtRHQSo77ZgEcN+jxzJtIhIlgeTQ== X-Google-Smtp-Source: ABdhPJxiDa36aj7oJzdqQAFHYPvka3nFJMOqYSaJsu5fLBQF5s+yCqL0jQcbYbFoW3EpGqYa5S3Qlg== X-Received: by 2002:a05:620a:2e6:: with SMTP id a6mr33753890qko.375.1607980994384; Mon, 14 Dec 2020 13:23:14 -0800 (PST) Received: from mail-qk1-f169.google.com (mail-qk1-f169.google.com. [209.85.222.169]) by smtp.gmail.com with ESMTPSA id l20sm17456243qtu.25.2020.12.14.13.23.13 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 14 Dec 2020 13:23:13 -0800 (PST) Received: by mail-qk1-f169.google.com with SMTP id i67so9584941qkf.11; Mon, 14 Dec 2020 13:23:13 -0800 (PST) X-Received: by 2002:ae9:f312:: with SMTP id p18mr33867332qkg.311.1607980993194; Mon, 14 Dec 2020 13:23:13 -0800 (PST) MIME-Version: 1.0 References: <202008251330.07PDU4WQ055570@repo.freebsd.org> In-Reply-To: From: Ryan Libby Date: Mon, 14 Dec 2020 13:23:02 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: svn commit: r364761 - in head: share/mk sys/conf sys/modules/cloudabi32 sys/modules/cloudabi64 sys/modules/linux sys/modules/linux64 To: Alexander Richardson Cc: src-committers , svn-src-all , svn-src-head , Brooks Davis , Ed Maste , John Baldwin Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4CvvWS0x0Wz3rBS X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-4.00 / 15.00]; REPLY(-4.00)[] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Dec 2020 21:23:16 -0000 On Mon, Dec 14, 2020 at 2:33 AM Alexander Richardson wrote: > > On Sun, 13 Dec 2020 at 19:22, Ryan Libby wrote: > > > > On Tue, Aug 25, 2020 at 6:30 AM Alex Richardson wrote: > > > > > > Author: arichardson > > > Date: Tue Aug 25 13:30:03 2020 > > > New Revision: 364761 > > > URL: https://svnweb.freebsd.org/changeset/base/364761 > > > > > > Log: > > > Pass -fuse-ld=/path/to/ld if ${LD} != "ld" > > > > > > This is needed so that setting LD/XLD is not ignored when linking with $CC > > > instead of directly using $LD. Currently only clang accepts an absolute > > > path for -fuse-ld= (Clang 12+ will add a new --ld-path flag), so we now > > > warn when building with GCC and $LD != "ld" since that might result in the > > > wrong linker being used. > > > > > > We have been setting XLD=/path/to/cheri/ld.lld in CheriBSD for a long time and > > > used a similar version of this patch to avoid linking with /usr/bin/ld. > > > This change is also required when building FreeBSD on an Ubuntu with Clang: > > > In that case we set XCC=/usr/lib/llvm-10/bin/clang and since > > > /usr/lib/llvm-10/bin/ does not contain a "ld" binary the build fails with > > > `clang: error: unable to execute command: Executable "ld" doesn't exist!` > > > unless we pass -fuse-ld=/usr/lib/llvm-10/bin/ld.lld. > > > > > > This change passes -fuse-ld instead of copying ${XLD} to WOLRDTMP/bin/ld > > > since then we would have to ensure that this file does not exist while > > > building the bootstrap tools. The cross-linker might not be compatible with > > > the host linker (e.g. when building on macos: host-linker= Mach-O /usr/bin/ld, > > > cross-linker=LLVM ld.lld). > > > > > > Reviewed By: brooks, emaste > > > Differential Revision: https://reviews.freebsd.org/D26055 > > > > > > Modified: > > > head/share/mk/bsd.sys.mk > > > head/sys/conf/kern.mk > > > head/sys/conf/kern.post.mk > > > head/sys/modules/cloudabi32/Makefile > > > head/sys/modules/cloudabi64/Makefile > > > head/sys/modules/linux/Makefile > > > head/sys/modules/linux64/Makefile > > > > > > Modified: head/share/mk/bsd.sys.mk > > > ============================================================================== > > > --- head/share/mk/bsd.sys.mk Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/share/mk/bsd.sys.mk Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -284,6 +284,19 @@ CFLAGS+= ERROR-tried-to-rebuild-during-make-install > > > .endif > > > .endif > > > > > > +# Please keep this if in sync with kern.mk > > > +.if ${LD} != "ld" && (${CC:[1]:H} != ${LD:[1]:H} || ${LD:[1]:T} != "ld") > > > +# Add -fuse-ld=${LD} if $LD is in a different directory or not called "ld". > > > +# Note: Clang 12+ will prefer --ld-path= over -fuse-ld=. > > > +.if ${COMPILER_TYPE} == "clang" > > > +LDFLAGS+= -fuse-ld=${LD:[1]} > > > +.else > > > +# GCC does not support an absolute path for -fuse-ld so we just print this > > > +# warning instead and let the user add the required symlinks. > > > +.warning LD (${LD}) is not the default linker for ${CC} but -fuse-ld= is not supported > > > > FYI: This causes a huge amount of wrong and irrelevant warnings in the > > build log for gcc cross compilers with XLD set, such as the toolchain > > from pkg install amd64-xtoolchain-gcc. That causes XLD to be set (via > > CROSS_BINUTILS_PREFIX in Makefile.inc1) to a path which is indeed the > > default linker for the cross compiler. The warnings are harmless, but > > annoying. Sorry, I don't have a suggestion for a better method. > > > > You can see an example in the build log from a gcc build in CI here > > (although note that the build currently fails for unrelated reasons): > > https://ci.freebsd.org/job/FreeBSD-head-amd64-gcc6_build/3131 > > > Hi Ryan, > > I think there are (at least) 3 options to fix/silence this warning: > > 1) The easiest option would be to turn off this warning for GCC builds > and hope that the user-supplied LD matches the one that GCC will > invoke. > Thanks for looking at it. I don't have a strong feeling about it, but I think simple is good so I'm also fine with (1). > 2) Another option could be to ask GCC for what it thinks the default > linker is and use that in the toolchain file, and update the check to > use `${CC} --print-prog-name ld` instead of (${CC:[1]:H} != > ${LD:[1]:H} || ${LD:[1]:T} != "ld") > $ /usr/local/bin/mips-unknown-freebsd12.1-gcc6 --print-prog-name ld > /usr/local/bin/mips-unknown-freebsd12.1-ld > $ /usr/local/bin/mips-unknown-freebsd12.1-gcc6 --print-prog-name ld.bfd > /usr/local/lib/gcc/mips-unknown-freebsd12.1/6.5.0/../../../../mips-unknown-freebsd12.1/bin/ld.bfd > Examining this, in amd64-xtoolchain-gcc: XCC=/usr/local/bin/x86_64-unknown-freebsd13.0-gcc ... CROSS_BINUTILS_PREFIX=/usr/local/x86_64-unknown-freebsd13.0/bin/ ... but % /usr/local/bin/x86_64-unknown-freebsd13.0-gcc --print-prog-name=ld /usr/local/bin/x86_64-unknown-freebsd13.0-ld % /usr/local/bin/x86_64-unknown-freebsd13.0-gcc --sysroot=/usr/obj/gcc6/usr/src/freebsd/amd64.amd64/tmp -B/usr/local/x86_64-unknown-freebsd13.0/bin/ --print-prog-name=ld /usr/local/bin/x86_64-unknown-freebsd13.0-ld So I was not exactly correct, above. They're hard links to the same ld program, but through different paths (even with -B as it appears in the build). I'm assuming this is okay but now I wonder if the xtoolchain is slightly misconfigured, or if gcc is lying (it's not reporting the path from -B)... ...okay, examining ports/devel/freebsd-gcc6/Makefile: --with-ld=${LOCALBASE}/bin/${BU_PREFIX}-ld So the xtoolchain gcc linker can't be influenced with -B. Hmm. It seems wrong that XCC's default linker path is different from XLD, even if they are links to the same file. Anyway, all that is to say, I think that this sounds good in concept but may also need either a fix in the xtoolchain or more hackery in the make files. > 2a) We could also use ${CC} -xc /dev/null -o /dev/null -Wl,--version` > to detect linker features in bsd.linker.mk and check if that matches > the value returned by ${LD} --version. > > 3) Change the xtoolchain installed a gcc-N hardlink in > /usr/local/-unknown-freebsd/bin and use that as ${CC}. > It would match then the ld directory and the existing check could > work. This seems okay to me but it sounds like a big change for a warning, and anyway I think (2) is probably a more reliable method of determining the default linker. It would seem to make some sense for a toolchain to have a whole directory with links to all the tools. However I'm not an expert here. > > I'd personally opt for 1 since I don't build with GCC and don't have > time right now to implement the other options. > Let me know what you think. > > Thanks, > Alex (CC'd jhb in case he has an opinion on the xtoolchain --with-ld vs XLD bit.) Thanks, Ryan > > > > +.endif > > > +.endif > > > + > > > # Tell bmake not to mistake standard targets for things to be searched for > > > # or expect to ever be up-to-date. > > > PHONY_NOTMAIN = analyze afterdepend afterinstall all beforedepend beforeinstall \ > > > > > > Modified: head/sys/conf/kern.mk > > > ============================================================================== > > > --- head/sys/conf/kern.mk Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/conf/kern.mk Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -270,6 +270,22 @@ CFLAGS+= -std=iso9899:1999 > > > CFLAGS+= -std=${CSTD} > > > .endif # CSTD > > > > > > +# Please keep this if in sync with bsd.sys.mk > > > +.if ${LD} != "ld" && (${CC:[1]:H} != ${LD:[1]:H} || ${LD:[1]:T} != "ld") > > > +# Add -fuse-ld=${LD} if $LD is in a different directory or not called "ld". > > > +# Note: Clang 12+ will prefer --ld-path= over -fuse-ld=. > > > +.if ${COMPILER_TYPE} == "clang" > > > +# Note: unlike bsd.sys.mk we can't use LDFLAGS here since that is used for the > > > +# flags required when linking the kernel. We don't need those flags when > > > +# building the vdsos. However, we do need -fuse-ld, so use ${CCLDFLAGS} instead. > > > +CCLDFLAGS+= -fuse-ld=${LD:[1]} > > > +.else > > > +# GCC does not support an absolute path for -fuse-ld so we just print this > > > +# warning instead and let the user add the required symlinks. > > > +.warning LD (${LD}) is not the default linker for ${CC} but -fuse-ld= is not supported > > > +.endif > > > +.endif > > > + > > > # Set target-specific linker emulation name. > > > LD_EMULATION_aarch64=aarch64elf > > > LD_EMULATION_amd64=elf_x86_64_fbsd > > > > > > Modified: head/sys/conf/kern.post.mk > > > ============================================================================== > > > --- head/sys/conf/kern.post.mk Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/conf/kern.post.mk Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -228,7 +228,7 @@ kernel-clean: > > > # in the a.out ld. For now, this works. > > > hack.pico: Makefile > > > :> hack.c > > > - ${CC} -shared ${CFLAGS} -nostdlib hack.c -o hack.pico > > > + ${CC} ${CCLDFLAGS} -shared ${CFLAGS} -nostdlib hack.c -o hack.pico > > > rm -f hack.c > > > > > > offset.inc: $S/kern/genoffset.sh genoffset.o > > > > > > Modified: head/sys/modules/cloudabi32/Makefile > > > ============================================================================== > > > --- head/sys/modules/cloudabi32/Makefile Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/modules/cloudabi32/Makefile Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -33,7 +33,7 @@ BINARY_ARCHITECTURE=i386 > > > .endif > > > > > > cloudabi32_vdso.o: ${VDSO_SRCS} > > > - ${CC} -x assembler-with-cpp -m32 -shared -nostdinc -nostdlib \ > > > + ${CC} ${CCLDFLAGS} -x assembler-with-cpp -m32 -shared -nostdinc -nostdlib \ > > > -Wl,-T${SYSDIR}/compat/cloudabi/cloudabi_vdso.lds \ > > > ${VDSO_SRCS} -o ${.TARGET} > > > > > > > > > Modified: head/sys/modules/cloudabi64/Makefile > > > ============================================================================== > > > --- head/sys/modules/cloudabi64/Makefile Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/modules/cloudabi64/Makefile Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -25,7 +25,7 @@ BINARY_ARCHITECTURE=i386 > > > .endif > > > > > > cloudabi64_vdso.o: ${VDSO_SRCS} > > > - ${CC} -x assembler-with-cpp -shared -nostdinc -nostdlib \ > > > + ${CC} ${CCLDFLAGS} -x assembler-with-cpp -shared -nostdinc -nostdlib \ > > > -Wl,-T${SYSDIR}/compat/cloudabi/cloudabi_vdso.lds \ > > > ${VDSO_SRCS} -o ${.TARGET} > > > > > > > > > Modified: head/sys/modules/linux/Makefile > > > ============================================================================== > > > --- head/sys/modules/linux/Makefile Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/modules/linux/Makefile Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -54,7 +54,7 @@ linux${SFX}_assym.h: linux${SFX}_genassym.o > > > sh ${SYSDIR}/kern/genassym.sh linux${SFX}_genassym.o > ${.TARGET} > > > > > > linux${SFX}_locore.o: linux${SFX}_assym.h assym.inc > > > - ${CC} -x assembler-with-cpp -DLOCORE -m32 -shared -s \ > > > + ${CC} ${CCLDFLAGS} -x assembler-with-cpp -DLOCORE -m32 -shared -s \ > > > -pipe -I. -I${SYSDIR} ${WERROR} -Wall -fno-common -nostdinc -nostdlib \ > > > -fno-omit-frame-pointer -fPIC \ > > > -Wl,-T${SRCTOP}/sys/${MACHINE_CPUARCH}/linux${SFX}/${VDSO}.lds.s \ > > > > > > Modified: head/sys/modules/linux64/Makefile > > > ============================================================================== > > > --- head/sys/modules/linux64/Makefile Tue Aug 25 13:29:57 2020 (r364760) > > > +++ head/sys/modules/linux64/Makefile Tue Aug 25 13:30:03 2020 (r364761) > > > @@ -30,7 +30,7 @@ linux_assym.h: linux_genassym.o > > > sh ${SYSDIR}/kern/genassym.sh linux_genassym.o > ${.TARGET} > > > > > > linux_locore.o: linux_locore.asm linux_assym.h > > > - ${CC} -x assembler-with-cpp -DLOCORE -shared -mcmodel=small \ > > > + ${CC} ${CCLDFLAGS} -x assembler-with-cpp -DLOCORE -shared -mcmodel=small \ > > > -pipe -I. -I${SYSDIR} ${WERROR} -Wall -fno-common -fPIC -nostdinc \ > > > -Wl,-T${SRCTOP}/sys/${MACHINE}/linux/${VDSO}.lds.s \ > > > -Wl,-soname=${VDSO}.so.1,-warn-common -nostdlib \