Date: Fri, 30 Mar 2018 11:12:28 -0500 From: Kyle Evans <kevans@freebsd.org> To: John Baldwin <jhb@freebsd.org> Cc: ports-committers@freebsd.org, svn-ports-all@freebsd.org, svn-ports-head@freebsd.org Subject: Re: svn commit: r465416 - in head/devel: aarch64-gcc amd64-gcc mips-gcc mips64-gcc powerpc64-gcc sparc64-gcc Message-ID: <CACNAnaF8r-kLsrhnSsiEC4ae1%2BkmBTEbzm0A5YF=ySa5_cHerQ@mail.gmail.com> In-Reply-To: <201803232353.w2NNrqnJ028176@repo.freebsd.org> References: <201803232353.w2NNrqnJ028176@repo.freebsd.org>
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On Fri, Mar 23, 2018 at 6:53 PM, John Baldwin <jhb@freebsd.org> wrote: > Author: jhb (src,doc committer) > Date: Fri Mar 23 23:53:52 2018 > New Revision: 465416 > URL: https://svnweb.freebsd.org/changeset/ports/465416 > > Log: > Fix --sysroot for cross-toolchain GCC packages > > By default, GCC assumes that a cross compiler should not have any valid > initial include or library paths aside from /usr/local/lib/gcc/<mumble>/. > This means that one cannot use --sysroot to point to a system root for > another architecture and have GCC automatically look for headers in > ${sysroot}/usr/include, etc. Currently we workaround this in FreeBSD's > build system with explicit -isystem, -B, and -L directives. However, > this is cumbersome compared to clang (where a bare --sysroot DTRT) > especially when using the compiler to build other software (such as test > programs, etc.). > > One can override GCC's assumption and force it to assume that it should > honor --sysroot by setting the '--with-sysroot' option to force GCC to > assume a specific system root. By setting this to '/', this means that > the cross-compiler will attempt to use the host's headers by default > if --sysroot is not specified, but if --sysroot is specified then > it is fully honored including for include paths and library paths. With > this change I can now cross-compile both C and C++ binaries simply by > using --sysroot without the need for -isystem, -B, or -L directives. Note > that the base/gcc and devel/riscv64-gcc ports both use --with-sysroot='/' > already. > > By default, GCC looks for headers in /usr/local/include (under the > sysroot) before /usr/include. To disable this and only look for headers > in /usr/include, patch gcc/Makefile.in to not define LOCAL_INCLUDE_DIR. > > Once -nostdinc is no longer required, the headers installed along with the > compiler are now used for compiling worlds and test programs. The "fixed" > headers in include-fixed are generally not helpful and are also derived > from the host's headers which might not match the target --sysroot, so > just delete them entirely. Even the stub limits.h headers GCC ships when > using an empty build sysroot are not helpful and need to be removed. > > On a related note, I also fixed the name of the C++ include directory > option to configure. By my reading it is 'with-gxx-include-dir' rather > than 'with-gcc-include-dir'. > > Reviewed by: bapt, brooks, kan > Sponsored by: DARPA / AFRL > Differential Revision: https://reviews.freebsd.org/D14627 > > Modified: > head/devel/aarch64-gcc/pkg-plist > head/devel/amd64-gcc/pkg-plist > head/devel/mips-gcc/pkg-plist > head/devel/mips64-gcc/pkg-plist > head/devel/powerpc64-gcc/Makefile > head/devel/powerpc64-gcc/pkg-plist > head/devel/sparc64-gcc/pkg-plist > Hey John, Documentation is eluding me here- what was --with-sysroot before? For other applications, is there a way to force the old behavior while invoking gcc? This appears to have caused arm-none-eabi-newlib to fail to build [1], I guess because it's pulling in a different <limits.h> (our limits.h?) without some LONG_LONG_MAX definitions that it needs. I can patch it to use LLONG_ instead of LONG_LONG_, but I have mixed feelings about compiling it in this new world order rather than the old world order that it's been tested in and expects. Thanks, Kyle Evans [1] http://package19.nyi.freebsd.org/data/103i386-default-build-as-user/465853/logs/arm-none-eabi-newlib-2.4.0_1.log
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