#!/bin/bash

# Copyright 2017  Andrew Clemons, Wellington, New Zealand
# Copyright 2017, 2018, 2019, 2020, 2021  Patrick J. Volkerding, Sebeka, Minnesota, USA
# Copyright 2017  Stuart Winter
# All rights reserved.
#
# Redistribution and use of this script, with or without modification, is
# permitted provided that the following conditions are met:
#
# 1. Redistributions of this script must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

cd $(dirname $0) ; CWD=$(pwd)

PKGNAM=rust
SRCNAM="${PKGNAM}c"
VERSION=${VERSION:-1.58.1}
BUILD=${BUILD:-1}

# Set this to YES to build with the system LLVM, or NO to use the bundled LLVM.
# YES is probably better (when it works...)
SYSTEM_LLVM=${SYSTEM_LLVM:-YES}

# Bootstrap variables (might not be kept updated for latest Rust):
RSTAGE0_VERSION=${RSTAGE0_VERSION:-1.57.0}
RSTAGE0_DIR=${RSTAGE0_DIR:-2021-12-02}
CSTAGE0_VERSION=${CSTAGE0_VERSION:-1.57.0}
CSTAGE0_DIR=${CSTAGE0_DIR:-$RSTAGE0_DIR}

# Automatically determine the architecture we're building on:
MARCH=$( uname -m )
if [ -z "$ARCH" ]; then
  case "$MARCH" in
    i?86)    export ARCH=i686 ;;
    armv7hl) export ARCH=$MARCH ;;
    arm*)    export ARCH=arm ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
    *)       export ARCH=$MARCH ;;
  esac
fi
unset MARCH

# For compiling i686 under an x86_64 kernel:
if [ "$(uname -m)" = "x86_64" -a "$(file -L /usr/bin/gcc | grep 80386 | grep 32-bit)" != "" ]; then
  ARCH=i686
fi

# If the variable PRINT_PACKAGE_NAME is set, then this script will report what
# the name of the created package would be, and then exit. This information
# could be useful to other scripts.
if [ ! -z "${PRINT_PACKAGE_NAME}" ]; then
  echo "$PKGNAM-$VERSION-$ARCH-$BUILD.txz"
  exit 0
fi

# If the bootstrap binaries are present, use those. Otherwise bootstrap from
# installed compiler.
if /bin/ls *-unknown-linux-gnu.tar.?z 1> /dev/null 2> /dev/null ; then
  LOCAL_BOOTSTRAP=no
else
  LOCAL_BOOTSTRAP=yes
fi

# https://forge.rust-lang.org/platform-support.html
# Bootstrapping ARCH:
if [ "$ARCH" = "i586" ]; then
  if [ "$LOCAL_BOOTSTRAP" = "yes" ] ; then
    if rustc -Vv | grep host | grep i586 > /dev/null ; then
      BARCH="$ARCH"
    else
      BARCH="i686"
      if case "$( uname -m )" in i586) true ;; *) false ;; esac ; then
        echo "rust must be bootstrapped from an i686 machine"
        exit 1
      fi
    fi
  else
    # i586 must be built on a i686 machine, since the bootstrap compiler is i686
    BARCH="i686"
    if case "$( uname -m )" in i586) true ;; *) false ;; esac ; then
      echo "rust must be bootstrapped from an i686 machine"
      exit 1
    fi
  fi
  TARCH="$ARCH"
elif [ "$ARCH" = "armv7hl" ]; then
  BARCH="armv7"
  TARCH="$BARCH"
else
  BARCH="$ARCH"
  TARCH="$ARCH"
fi

# Bootstrapping ABI:
if [ "$ARCH" = "armv7hl" ]; then
  BABI="gnueabihf"
else
  BABI="gnu"
fi

TMP=${TMP:-/tmp}
OUTPUT=${OUTPUT:-/tmp}
PKG=$TMP/package-$PKGNAM

# Not needed, as the build will automatically use as many jobs as there are
# threads.
#NUMJOBS=${NUMJOBS:-" -j$(expr $(nproc) + 1) "}

if [ "$ARCH" = "i586" ]; then
  LIBDIRSUFFIX=""
elif [ "$ARCH" = "i686" ]; then
  LIBDIRSUFFIX=""
elif [ "$ARCH" = "x86_64" ]; then
  LIBDIRSUFFIX="64"
elif [ "$ARCH" = "armv7hl" ]; then
  LIBDIRSUFFIX=""
else
  LIBDIRSUFFIX=""
fi

rm -rf $PKG
mkdir -p $TMP $PKG $OUTPUT
cd $TMP
rm -rf $SRCNAM-$VERSION-src
tar xvf $CWD/$SRCNAM-$VERSION-src.tar.?z || exit 1
cd $SRCNAM-$VERSION-src || exit 1

# Link with -lffi in case of using system LLVM:
if [ "${SYSTEM_LLVM}" = "YES" ]; then
  zcat $CWD/link_libffi.diff.gz | patch -p1 --verbose || exit 1
fi

if [ "$LOCAL_BOOTSTRAP" != "yes" ] ; then
  # rust requires bootstrapping with the previous rust version.
  # versions are defined in src/stage0.txt.
  mkdir -p build/cache/$RSTAGE0_DIR
  cp $CWD/$PKGNAM-std-$RSTAGE0_VERSION-$BARCH-unknown-linux-gnu.tar.?z \
     $CWD/$SRCNAM-$RSTAGE0_VERSION-$BARCH-unknown-linux-gnu.tar.?z \
     build/cache/$RSTAGE0_DIR
  mkdir -p build/cache/$CSTAGE0_DIR
  cp $CWD/cargo-$CSTAGE0_VERSION-$BARCH-unknown-linux-gnu.tar.?z build/cache/$CSTAGE0_DIR
fi

# Build configuration:
cat << EOF > config.toml
[llvm]
ccache = "/usr/bin/ccache"
link-shared = true

[build]
build = "$BARCH-unknown-linux-$BABI"
host = ["$TARCH-unknown-linux-$BABI"]
target = ["$TARCH-unknown-linux-$BABI"]
tools = ["analysis", "cargo", "clippy", "rls", "rustfmt", "src"]
submodules = false
vendor = true
extended = true

[install]
prefix = "/usr"
docdir = "doc/rust-$VERSION"
libdir = "lib$LIBDIRSUFFIX"
mandir = "man"

[rust]
codegen-units = 0
channel = "stable"
rpath = false
codegen-tests = false
ignore-git = true

EOF

if [ "${SYSTEM_LLVM}" = "YES" ]; then
  cat << EOF >> config.toml
# Add this stuff to build with the system LLVM:
[target.i586-unknown-linux-gnu]
llvm-config = "/usr/bin/llvm-config"

[target.i686-unknown-linux-gnu]
llvm-config = "/usr/bin/llvm-config"

[target.x86_64-unknown-linux-gnu]
llvm-config = "/usr/bin/llvm-config"

[target.armv7-unknown-linux-gnueabihf]
llvm-config = "/usr/bin/llvm-config"
EOF
fi

if [ "$LOCAL_BOOTSTRAP" = "yes" ] ; then
  sed -i "s|^\(extended = true\)$|\1\nrustc = \"/usr/bin/rustc\"\ncargo = \"/usr/bin/cargo\"|" config.toml
fi

chown -R root:root .
find -L . \
 \( -perm 777 -o -perm 775 -o -perm 750 -o -perm 711 -o -perm 555 \
  -o -perm 511 \) -exec chmod 755 {} \+ -o \
 \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \+

export PKG_CONFIG_ALLOW_CROSS=1

if [ "$BARCH" = "i586" ] ; then
  # when bootstrapping from i586 (rust already installed), also build a i686
  # rustlib:
  sed -i 's/^target =.*$/target = ["i686-unknown-linux-gnu"]/' config.toml
elif [ "$BARCH" = "i686" ] ; then
  if [ "$TARCH" = "i586" ] ; then
    # this will cause some messages like:
    # warning: redundant linker flag specified for library `m`
    # but will keep the build from falling over when doing the stage1 compiler
    # linking for the i586 compiler. seems the correct flags don't get passed
    # through and we end up failures like:
    # error: linking with `clang` failed: exit code: 1
    # /tmp/SBo/rustc-1.20.0-src/build/i686-unknown-linux-gnu/stage1-rustc/i586-unknown-linux-gnu/release/deps/librustc_llvm-4ab259c9aed547db.so: undefined reference to `xxx`
    export RUSTFLAGS="$RUSTFLAGS -C link-args=-lrt -ldl -lcurses -lpthread -lz -lm"
  fi
fi

# Build and install:
python3 ./x.py build || exit 1
DESTDIR=$PKG python3 x.py install || exit 1

# Eh, none of this is all that big. Might as well leave it around as a
# reference.
#rm -f $PKG/usr/lib$LIBDIRSUFFIX/rustlib/components
#rm -f $PKG/usr/lib$LIBDIRSUFFIX/rustlib/install.log
#rm -f $PKG/usr/lib$LIBDIRSUFFIX/rustlib/manifest-*
#rm -f $PKG/usr/lib$LIBDIRSUFFIX/rustlib/rust-installer-version
#rm -f $PKG/usr/lib$LIBDIRSUFFIX/rustlib/uninstall.sh
# Make sure the paths are correct, though:
sed -i "s,/tmp/package-rust/,/,g" $PKG/usr/lib$LIBDIRSUFFIX/rustlib/install.log $PKG/usr/lib$LIBDIRSUFFIX/rustlib/manifest-*
# And a little compression doesn't hurt either:
gzip -9 $PKG/usr/lib$LIBDIRSUFFIX/rustlib/manifest-*

# Move bash completions to the system location:
if [ -d $PKG/etc/bash_completion.d ]; then
  mkdir -p $PKG/usr/share/bash-completion
  mv $PKG/etc/bash_completion.d $PKG/usr/share/bash-completion/completions
  rmdir $PKG/etc 2> /dev/null
fi

# Correct permissions on shared libraries:
find $PKG/usr/lib$LIBDIRSUFFIX -name "*.so" -exec chmod 755 "{}" \+

# Evidently there are a lot of duplicated libraries in this tree, so let's
# try to save some space:
( cd $PKG/usr/lib${LIBDIRSUFFIX}/rustlib/*-linux-gnu/lib && for file in *.so ; do if cmp -s $file ../../../$file ; then ln -sf ../../../$file .; fi; done )

# Strip ELF objects:
find $PKG -print0 | xargs -0 file | grep -e "executable" -e "shared object" | grep ELF \
  | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || true

# Get rid of a possible duplicated libLLVM. Not only is it large, but it also
# throws an error at boot with ldconfig:
rm -f $PKG/usr/lib${LIBDIRSUFFIX}/libLLVM-*.so.old

# Commented out (for now) since we disable rpaths in config.toml:
## Remove any compiled-in RPATHs:
#find $PKG -print0 | xargs -0 file | grep -e "executable" -e "shared object" | grep ELF \
#  | cut -f 1 -d : | while read elfobject ; do
#  patchelf --remove-rpath $elfobject || exit 1
#done

# Compress man pages:
find $PKG/usr/man -type f -exec gzip -9 {} \+
for i in $( find $PKG/usr/man -type l ) ; do ln -s $( readlink $i ).gz $i.gz ; rm $i ; done

# Add some documentation:
mkdir -p $PKG/usr/doc/$PKGNAM-$VERSION
cp -a *.md COPYRIGHT* COPYING* LICENSE* $PKG/usr/doc/$PKGNAM-$VERSION
# Include licenses from third party vendors:
mkdir $PKG/usr/doc/$PKGNAM-$VERSION/vendor
( cd vendor
  tar cf - $(find . -maxdepth 2 | grep -e README -e LICENSE -e COPYING -e CHANGELOG -e PERFORMANCE -e UPGRADE ) | ( cd $PKG/usr/doc/$PKGNAM-$VERSION/vendor ; tar xf - )
)

mkdir -p $PKG/install
cat $CWD/slack-desc > $PKG/install/slack-desc

cd $PKG
/sbin/makepkg -l y -c n $OUTPUT/$PKGNAM-$VERSION-$ARCH-$BUILD.txz