As discussed in https://bugs.gentoo.org/show_bug.cgi?id=474748#c37, clang builds almost OOB in prefix on OS X now. What still needs doing so prefix can be bootstrapped directly into clang? - binutils-apple supports being compiled with clang and libcxx. It has a USE flag to force libcxx usage. They've been tested back to 10.4. - clang should compile fine with the host tools. Rather it's quite difficult to make it not use them later on. That's been tested back to 10.4 as well. - libcxx ebuilds (https://bugs.gentoo.org/show_bug.cgi?id=538364) require clang and use it unconditionally. They are tested back to 10.4 and compile nicely with clang-3.4.2. So there should be only two scenarios: osx106:~ michael$ clang++ -std=c++11 -stdlib=libc++ -o t t.cpp clang: error: invalid deployment target for -stdlib=libc++ (requires Mac OS X 10.7 or later) 1. >= 10.7: Host has support for clang -std=c++11 -stdlib=libc++: We should be able to compile binutils-apple, clang-3.5.1 and libcxx-apple directly as the stage2 compiler using the host compiler. Since binutils-apple and clang-3.4.2 can be compiled using gcc-4.2.1, no special care would need to be taken to force use of the host's clang for the bootstrap. For completeness' sake the default versions on different versions are listed below. 2. <10.7 has no support for C++11: Here we'd need to compile binutils-apple, clang-3.4.2 and libcxx-apple in stage 2 which could then either be upgraded to 3.5.1 before moving on or just compile 3.5.1 for stage3 of bootstrapping. >=10.6's default compiler is gcc-4.2.1 which we are nowadays using inside the prefix to compile clang-3.4.2 anyways. 10.5 has gcc-4.2.1 as well but it needs to be called as gcc-4.2 explicitly. 10.4 hasn't got gcc-4.2 which might get hary for bootstrapping clang-3.4.2. Here the three-stage approach we are using now would be necessary: host gcc-4.0.1 -> gcc-apple-4.2.1 -> clang-3.4.2 -> clang-3.5.1. The last two steps could IMO be left up to the user, retaining the current bootstrapping scheme for 10.4. osx104:~ michael$ cc -v Using built-in specs. Target: i686-apple-darwin8 Configured with: /var/tmp/gcc/gcc-5370~2/src/configure --disable-checking -enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib --build=powerpc-apple-darwin8 --with-arch=nocona --with-tune=generic --program-prefix= --host=i686-apple-darwin8 --target=i686-apple-darwin8 Thread model: posix gcc version 4.0.1 (Apple Computer, Inc. build 5370) osx104:~ michael$ gcc -v Using built-in specs. Target: i686-apple-darwin8 Configured with: /var/tmp/gcc/gcc-5370~2/src/configure --disable-checking -enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib --build=powerpc-apple-darwin8 --with-arch=nocona --with-tune=generic --program-prefix= --host=i686-apple-darwin8 --target=i686-apple-darwin8 Thread model: posix gcc version 4.0.1 (Apple Computer, Inc. build 5370) osx104:~ michael$ gcc-4.2 -v -bash: gcc-4.2: command not found osx104:~ michael$ clang -v -bash: clang: command not found osx105:~ michael$ cc -v Using built-in specs. Target: i686-apple-darwin9 Configured with: /var/tmp/gcc/gcc-5493~1/src/configure --disable-checking -enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib --build=i686-apple-darwin9 --with-arch=apple --with-tune=generic --host=i686-apple-darwin9 --target=i686-apple-darwin9 Thread model: posix gcc version 4.0.1 (Apple Inc. build 5493) osx105:~ michael$ gcc -v Using built-in specs. Target: i686-apple-darwin9 Configured with: /var/tmp/gcc/gcc-5493~1/src/configure --disable-checking -enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.0/ --with-gxx-include-dir=/include/c++/4.0.0 --with-slibdir=/usr/lib --build=i686-apple-darwin9 --with-arch=apple --with-tune=generic --host=i686-apple-darwin9 --target=i686-apple-darwin9 Thread model: posix gcc version 4.0.1 (Apple Inc. build 5493) osx105:~ michael$ gcc-4.2 -v Using built-in specs. Target: i686-apple-darwin9 Configured with: /var/tmp/gcc_42/gcc_42-5574~1/src/configure --disable-checking --enable-werror --prefix=/usr --mandir=/usr/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin9 --with-gxx-include-dir=/usr/include/c++/4.0.0 --host=i686-apple-darwin9 --target=i686-apple-darwin9 Thread model: posix gcc version 4.2.1 (Apple Inc. build 5574) osx105:~ michael$ clang -v -bash: clang: command not found osx106:~ michael$ cc -v Using built-in specs. Target: i686-apple-darwin10 Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.1~3/src/configure --disable-checking --enable-werror --prefix=/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin10 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.1~3/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10 --target=i686-apple-darwin10 --with-gxx-include-dir=/usr/include/c++/4.2.1 Thread model: posix gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00) osx106:~ michael$ gcc -v Using built-in specs. Target: i686-apple-darwin10 Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.1~3/src/configure --disable-checking --enable-werror --prefix=/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin10 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.1~3/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10 --target=i686-apple-darwin10 --with-gxx-include-dir=/usr/include/c++/4.2.1 Thread model: posix gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.1.00) osx106:~ michael$ clang -v Apple clang version 3.0 (tags/Apple/clang-211.10.1) (based on LLVM 3.0svn) Target: x86_64-apple-darwin10.8.0 Thread model: posix osx107:~ michael$ cc -v Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn) Target: x86_64-apple-darwin11.4.2 Thread model: posix osx107:~ michael$ gcc -v Using built-in specs. Target: i686-apple-darwin11 Configured with: /private/var/tmp/llvmgcc42/llvmgcc42-2336.11~182/src/configure --disable-checking --enable-werror --prefix=/Applications/Xcode.app/Contents/Developer/usr/llvm-gcc-4.2 --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-prefix=llvm- --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin11 --enable-llvm=/private/var/tmp/llvmgcc42/llvmgcc42-2336.11~182/dst-llvmCore/Developer/usr/local --program-prefix=i686-apple-darwin11- --host=x86_64-apple-darwin11 --target=i686-apple-darwin11 --with-gxx-include-dir=/usr/include/c++/4.2.1 Thread model: posix gcc version 4.2.1 (Based on Apple Inc. build 5658) (LLVM build 2336.11.00) osx107:~ michael$ clang -v Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn) Target: x86_64-apple-darwin11.4.2 Thread model: posix osx108:~ michael$ cc -v Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn) Target: x86_64-apple-darwin12.5.0 Thread model: posix osx108:~ michael$ gcc -v Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn) Target: x86_64-apple-darwin12.5.0 Thread model: posix osx108:~ michael$ clang -v Apple LLVM version 5.1 (clang-503.0.40) (based on LLVM 3.4svn) Target: x86_64-apple-darwin12.5.0 Thread model: posix osx109:~ michael$ cc -v Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin13.4.0 Thread model: posix osx109:~ michael$ gcc -v Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin13.4.0 Thread model: posix osx109:~ michael$ clang -v Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin13.4.0 Thread model: posix michael@osx1010:~ # cc -v Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin14.1.0 Thread model: posix michael@nindamos:~ # gcc -v Configured with: --prefix=/Applications/Xcode.app/Contents/Developer/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin14.1.0 Thread model: posix michael@nindamos:~ # clang -v Apple LLVM version 6.0 (clang-600.0.56) (based on LLVM 3.5svn) Target: x86_64-apple-darwin14.1.0 Thread model: posix Reproducible: Always
I've added the libcxx ebuilds to the prefix overlay
I've allowed llvm to compile itself (ebuild-wise). I've got a bunch of modifications to the bootstrap process to bootstrap with Clang as system compiler (and Clang only) on OSX. This is based on your observations and instructions here. Sofar, I'm at the end of stage3, emerging llvm-3.6.1 fails. Will mask that one, once we figure out what is wrong with the asan bits.
This is now reality. At last. Thanks for all the hard work Michael!
