# clang-elfv2.mk
# Bootstrap toolchain for NATIVE powerpc64 elfv1 -> elfv2 ABI transition build.
# (For cross building, either update your native llvm with the flag
# day patches and then do a cross build, or force clang bootstrap
# with the patches in src.)

# HOWTO:
# Note: Commands assume you are in a bourne shell session.
#
# 0) * TEMPORARY UNTIL LLVM 8.0.1 LANDS *
#    Hack llvm80 build to be 8.0.1-rc2 or later (see distinfo 
#    history, there was an accidental commit that can be used)
#    Remember to update DISTVERSION=   8.0.1rc2
#    Build and install this updated llvm80.
#
# 1) Install this toolchain file to /usr/local/share/toolchains/
#
# 2) Apply outstanding llvm-elfv2 patches AND the flag day patches.
#
# 3) Manually symlink in a couple of legacy tools:
#  mkdir -p "/usr/obj/usr/src/powerpc.powerpc64/tmp/legacy/bin"
#  ln -s /usr/local/llvm80/bin/clang-tblgen /usr/obj/usr/src/powerpc.powerpc64/tmp/legacy/usr/bin/
#  ln -s /usr/local/llvm80/bin/llvm-tblgen /usr/obj/usr/src/powerpc.powerpc64/tmp/legacy/usr/bin/ 
#
# 4) Do a 64-bit cross buildworld using this toolchain file:
#  cd /usr/src
#  make CROSS_TOOLCHAIN=clang-elfv2 TARGET=powerpc TARGET_ARCH=powerpc64 WITHOUT_BOOT= WITHOUT_LIB32= buildworld -j32
#
# 5) Install this 64-bit only toolchain to a chroot.
#  mkdir /usr/elfv2_chroot
#  make CROSS_TOOLCHAIN=clang-elfv2 TARGET=powerpc TARGET_ARCH=powerpc64 WITHOUT_BOOT= WITHOUT_LIB32= installworld DESTDIR=/usr/elfv2_chroot
#  TARGET=powerpc TARGET_ARCH=powerpc64 WITHOUT_BOOT= WITHOUT_LIB32= mergemaster -p -i -D /usr/elfv2_chroot
#  mount -t devfs none /usr/elfv2_chroot/dev
#  cp -a /usr/src/. /usr/elfv2_chroot/usr/src/.
#
# 6) Do a second buildworld inside the chroot to do the full native build. 
#  chroot /usr/elfv2_chroot
#  cd /usr/src
#  make buildworld buildkernel KERNCONF=GENERIC64 -j32
#
# 7) Make release artifacts as desired. 

XCC=/usr/local/bin/clang80
XCXX=/usr/local/bin/clang++80
XCPP=/usr/local/bin/clang-cpp80
XLD=/usr/local/llvm80/bin/ld.lld
CROSS_BINUTILS_PREFIX=/var/empty
X_COMPILER_TYPE=clang
# Force ELFv2 so this works with unpatched clang.
XCFLAGS="-mabi=elfv2"
XCXXFLAGS="-mabi=elfv2"