#!/bin/bash
# $Id$
# Copyright 2024  Eric Hameleers, Eindhoven, NL
# All rights reserved.
#
#   Permission to use, copy, modify, and distribute this software for
#   any purpose with or without fee is hereby granted, provided that
#   the above copyright notice and this permission notice appear in all
#   copies.
#
#   THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 AUTHORS AND COPYRIGHT HOLDERS AND THEIR
#   CONTRIBUTORS 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.
#
# -----------------------------------------------------------------------------
#
# Build the llvm/rust toolchain from Google's customized sources
#
# By:              Eric Hameleers <alien@slackware.com>
# For:             chromium
# Needs:       
# Changelog:   
# 123-1            21/mar/2024 by Eric Hameleers <alien@slackware.com>
#                  * First version, targeting Chromium 123.
# 
# -----------------------------------------------------------------------------

SRCNAM="chromium"
PRGNAM="${SRCNAM}-compiler-toolchain"
SRCVER=${SRCVER:-124.0.6367.60}
VERSION=$(echo $SRCVER |cut -d. -f1)
BUILD=${BUILD:-1}
TAG=${TAG:-alien}

# Cross-compiling 32bit binaries on 64bit Slackware; set to "YES":
CROSS32=${CROSS32:-"NO"}

# Debug build (disabled by default):
USE_DEBUG=${USE_DEBUG:-0}

# Where do we look for sources?
SRCDIR=$(cd $(dirname $0); pwd)

# Place to build (TMP) package (PKG) and output (OUTPUT) the program:
TMP=${TMP:-/tmp/build}
PKG=$TMP/package-$PRGNAM
OUTPUT=${OUTPUT:-/tmp}

# Visible directory listing of anything Chrome related is:
#   http://gsdview.appspot.com/
# Official location (non-browsable) of the above is:
#   https://commondatastorage.googleapis.com/

##
## --- with a little luck, you won't have to edit below this point --- ##
##

# Automatically determine the architecture we're building on:
MARCH=$( uname -m )
if [ -z "$ARCH" ]; then
  case "$MARCH" in
    i?86)    export ARCH=i586 ;;
    armv7*)  export ARCH=$MARCH ;;
    arm*)    export ARCH=arm ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
    *)       export ARCH=$MARCH ;;
  esac
fi

case "$ARCH" in
  i?86)      SLKCFLAGS="-O2 -march=${ARCH} -mtune=i686"
             LIBDIRSUFFIX=""
             SYSROOT_ARCH="i386"
             SYSROOT_TARGET="i386-linux-gnu"
             PKGARCH="$ARCH"
             ;;
  x86_64)    # Ensure that 32bit libraries are found first if we cross-compile:
             if [ "${CROSS32}" = "YES" ]; then
               SLKCFLAGS="-O2"
               LIBDIRSUFFIX=""
               SLKLDFLAGS="-L/usr/lib"
               SYSROOT_ARCH="i386"
               SYSROOT_TARGET="i386-linux-gnu"
               PKGARCH="i586"
             else
               SLKCFLAGS="-O2 -fPIC"
               LIBDIRSUFFIX="64"
               SYSROOT_ARCH="amd64"
               SYSROOT_TARGET="x86_64-linux-gnu"
               PKGARCH="$ARCH"
             fi
             ;;
  armv7*)    SLKCFLAGS="-O2 -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=hard"
             SLKLDFLAGS="-Wl,-z,notext"
             LIBDIRSUFFIX=""
             SYSROOT_ARCH="arm"
             SYSROOT_TARGET="arm-linux-gnueabihf"
             PKGARCH="$ARCH"
             ;;
  *)         SLKCFLAGS=${SLKCFLAGS:-"O2"}
             SLKLDFLAGS=${SLKLDFLAGS:-""}
             LIBDIRSUFFIX=${LIBDIRSUFFIX:-""}
             SYSROOT_ARCH="$ARCH"
             SYSROOT_TARGET="$ARCH-linux-gnu"
             PKGARCH="$ARCH"
             ;;
esac

case "$ARCH" in
    armv7*)  TARGET=$ARCH-slackware-linux-gnueabi ;;
    arm*)    TARGET=${SYSROOT_ARCH}-slackware-linux-gnueabihf ;;
    *)       TARGET=$ARCH-slackware-linux ;;
esac

# Exit the script on errors:
set -e
trap 'echo "$0 FAILED at line ${LINENO}" | tee $OUTPUT/error-${PRGNAM}.log' ERR
# Catch unitialized variables:
set -u
P1=${1:-1}

# Save old umask and set to 0022:
_UMASK_=$(umask)
umask 0022

# Source locations:
SOURCE[0]="$SRCDIR/${SRCNAM}-${SRCVER}.tar.xz"
SRCURL[0]="https://commondatastorage.googleapis.com/${SRCNAM}-browser-official/${SRCNAM}-${SRCVER}.tar.xz"

# Create working directories:
mkdir -p $OUTPUT          # place for the package to be saved
mkdir -p $TMP/tmp-$PRGNAM # location to build the source
mkdir -p $PKG             # place for the package to be built
rm -rf $PKG/*             # always erase old package's contents
rm -rf $TMP/tmp-$PRGNAM/* # remove the remnants of previous build
rm -rf $OUTPUT/{configure,make,install,error,makepkg,patch}-$PRGNAM.log
                          # remove old log files

# Source file availability:
for (( i = 0; i < ${#SOURCE[*]}; i++ )) ; do
  if ! [ -f ${SOURCE[$i]} ]; then
    echo "Source '$(basename ${SOURCE[$i]})' not available yet..."
    # Check if the $SRCDIR is writable at all - if not, download to $OUTPUT
    [ -w "$SRCDIR" ] || SOURCE[$i]="$OUTPUT/$(basename ${SOURCE[$i]})"
    if [ -f ${SOURCE[$i]} ]; then echo "Ah, found it!"; continue; fi
    if ! [ "x${SRCURL[$i]}" == "x" ]; then
      echo "Will download file to $(dirname $SOURCE[$i])"
      wget --no-check-certificate -nv -T 20 -O "${SOURCE[$i]}" "${SRCURL[$i]}" || true
      if [ $? -ne 0 -o ! -s "${SOURCE[$i]}" ]; then
        echo "Fail to download '$(basename ${SOURCE[$i]})'. Aborting the build."
        mv -f "${SOURCE[$i]}" "${SOURCE[$i]}".FAIL
        exit 1
      fi
    else
      echo "File '$(basename ${SOURCE[$i]})' not available. Aborting the build."
      exit 1
    fi
  fi
done

if [ "$P1" == "--download" ]; then
  echo "Download complete."
  exit 0
fi

# --- PACKAGE BUILDING ---

echo "++"
echo "|| $PRGNAM-$VERSION"
echo "++"

echo Building ...

echo "Extracting the source archive(s) for $PRGNAM..."
cd $TMP/tmp-$PRGNAM
tar -xf ${SOURCE[0]}
cd ${SRCNAM}-${SRCVER}

# Fix the link on 32bit:
sed -e '/ldflags /s/-m32/&", "-Wl,-z,notext/' \
  -i build/config/compiler/BUILD.gn \
   2>&1 | tee -a $OUTPUT/patch-${PRGNAM}.log

# Prevent an error 'Looking for xmlReadMemory - not found ' building clang:
sed \
  -i tools/clang/scripts/build.py \
  -e "s%'lib'%'lib$LIBDIRSUFFIX'%g"
sed \
  -i third_party/libxml/src/libxml2-config.cmake.in \
  -e 's%set(LIBXML2_LIBRARY_DIR *${_libxml2_rootdir}/lib%&'${LIBDIRSUFFIX}'%'

# Prevent an error:
# 'c-index-test.c:679:3: error: unknown type name xmlRelaxNGPtr' building clang:
sed \
  -i tools/clang/scripts/build.py \
  -e "/DLLVM_ENABLE_LIBXML2=FORCE_ON/a   '-DCLANG_ENABLE_LIBXML2=OFF',"

# Do not embed a tensorflow model:
sed \
  -i tools/clang/scripts/build.py \
  -e "s/default='default' if sys.platform.startswith('linux') else ''/default=''/"

# Slackware specific:
# When compiling google's clang on 32bit Slackware or on ARM, add our triplets.
# I am a python noob so this is clumsy, better implementation is welcome :-)
cp $SRCDIR/patches/clang.toolchains.slackware.triple.diff .
cat $SRCDIR/patches/chromium_slackware_triplet.patch | patch -p1 --verbose \
  2>&1 | tee -a $OUTPUT/patch-${PRGNAM}.log

# When compiling google's clang, we want 32bit too - don't limit us, devs:
sed -i tools/clang/scripts/build.py -e "s/x86_64-unknown-linux-gnu/${SYSROOT_TARGET}/g"
if [ "$ARCH" == "i586" ] || [ "${CROSS32}" = "YES" ]; then
  sed -i tools/clang/scripts/build.py \
      -e "s/sysroot_amd64\([,)]\)/sysroot_i386\1/"
      # \
      #-e "s/LLVM_ENABLE_LLD=ON/LLVM_ENABLE_LLD=OFF/"

  # Non-functional vpython in the 32bit depot_tools:
  export VPYTHON_BYPASS="manually managed python not supported by chrome operations"
fi

# And fix the 32bit compilation while we are at it:
sed -i tools/clang/scripts/build.py -e "s/ldflags = \[\]/ldflags = \['-latomic','-lpthread'\]/"

# ARM platform specifics:
if [[ "$ARCH" =~ arm.* ]]; then
  # Fix the hard-coded bootstrap target 'X86':
  sed -i tools/clang/scripts/build.py \
    -e "s/bootstrap_targets = 'X86'/bootstrap_targets = 'ARM'/"

  # Compile only the relevant back-ends (ARM, AArch64 and X86):
  sed -i tools/clang/scripts/build.py \
    -e "s/\(^ *targets = \).*$/\1'ARM;X86;AArch64'/"
else
  # Compile only the relevant back-end (X86):
  sed -i tools/clang/scripts/build.py \
    -e "s/\(^ *targets = \).*$/\1'X86'/"
fi

# We require a 32bit gn binary, devs!
sed -i BUILD.gn \
  -e 's/target_os != "linux" || /target_os == "linux" || /'

export PATH="$TMP/tmp-$PRGNAM/${SRCNAM}-${SRCVER}/third_party/depot_tools:$PATH"

# Checking out LLVM demands that we tell git who we are:
cat <<EOT >$TMP/tmp-$PRGNAM/chromium_gitconfig
[user]
        email = alien@slackware.com
        name = Eric Hameleers
[safe]
        directory = $TMP/tmp-$PRGNAM/${SRCNAM}-${SRCVER}/third_party/rust-src
EOT
export GIT_CONFIG_GLOBAL=$TMP/tmp-$PRGNAM/curomium_gitconfig

# --- Compile --- #

# Final link uses lots of file descriptors.
ulimit -n 4096

echo "-- Building google's clang toolchain."
# Uses a sysroot image always for building LLVM, but since Chromium 121 the
# sysroot has some includes in a wrong place.
# So, let's download it ourselves and fix it before calling the build:
pushd tools/clang/scripts
  SYSROOT_LOC=$(python3  -c "import build; loc = build.DownloadDebianSysroot('${SYSROOT_ARCH}') ; print(loc)" |tail -1)
popd
SYSROOTDIR=$(basename $(ls third_party/llvm-build-tools/ |grep ${SYSROOT_ARCH}_sysroot))

# Copy missing includes:
rsync -Ha \
  third_party/llvm-build-tools/${SYSROOTDIR}/usr/include/${SYSROOT_TARGET}/ \
  third_party/llvm-build-tools/${SYSROOTDIR}/usr/include/
# Fix the script so that it does not again download and mangle the sysroot:
sed \
  -e "s%sysroot_${SYSROOT_ARCH} = DownloadDebianSysroot.*%sysroot_${SYSROOT_ARCH} = '"${SYSROOT_LOC}"'%" \
  -i tools/clang/scripts/build.py
unset SYSROOTDIR

HDR2REM=""
if [ "$ARCH" == "i586" ]; then
  # Actually 32bit compilation fails by not finding 'bits/c++config.h'.
  # I could only work around this using a kludge:
  # Keep a list of the symlinks we'll be creating:
  for HDR in /usr/include/c++/$(gcc -dumpversion)/${TARGET}/bits/*.h ; do
    if [ ! -f /usr/include/c++/$(gcc -dumpversion)/bits/$(basename $HDR) ];
  then
    ln -s $HDR /usr/include/c++/$(gcc -dumpversion)/bits/
    HDR2REM="$(basename $HDR) $HDR2REM"
    fi
  done
fi
export CFLAGS=""
export CXXFLAGS=""
export LDFLAGS=""
python3 tools/clang/scripts/build.py \
  --bootstrap \
  --skip-checkout \
  --pic \
  --disable-asserts \
  --host-cc /usr/bin/gcc \
  --host-cxx /usr/bin/g++ \
  --use-system-cmake \
  --no-tools \
  --without-android \
  --without-fuchsia \
  --without-zstd \
  2>&1 | tee $OUTPUT/clang_build-${PRGNAM}.log
  #--gcc-toolchain /usr \

# Output will be in:
# third_party/llvm-build/Release+Asserts/

# Building gn for Chromium 110 fails when this file is not present:
if [ ! -f third_party/llvm-build/Release+Asserts/cr_build_revision ]; then
  CLANG_REVISION=$(grep ^CLANG_REVISION tools/clang/scripts/update.py |cut -d= -f2 |tr -d " '")
  CLANG_SUB_REVISION=$(grep ^CLANG_SUB_REVISION tools/clang/scripts/update.py |cut -d= -f2 |tr -d " '")
  echo "${CLANG_REVISION}-${CLANG_SUB_REVISION}" > third_party/llvm-build/Release+Asserts/cr_build_revision
fi

##### Ensure that only this new clang is used, ignoring the system version:
####MYCLANG_PATH="$TMP/tmp-$PRGNAM/${SRCNAM}-${SRCVER}/third_party/llvm-build/Release+Asserts/bin"
####export PATH="$MYCLANG_PATH:$PATH"
####
####echo "-- Building google's rust toolchain."
####
####### NOTE ###
##### Google does not even consider 32bit Linux as a valid target, so we have to
##### hack support for 'i386' into the build infrastructure ourselves.
##### High-over:
##### - add i386 target to ./tools/rust/build*.py
##### - compile openssl as *static* libraries and install bin, include and lib
##### into ./third_party/llvm-build-tools/openssl/
##### - add ./third_party/llvm-build-tools/openssl/.cipdpkg/manifest.json
#####   containing:
##### {
#####  "format_version": "1.1",
#####  "package_name": "infra/3pp/static_libs/openssl/linux-i386",
#####  "install_mode": "copy"
##### }
##### - disable removing that openssl directory in build_rust.py
##### - ... and possibly lots more crap to fix
####### END NOTE ###
####
###### Next. build Rust against our custom compiler:
####LDFLAGS="$LDFLAGS" \
####python3 tools/rust/build_rust.py \
####  --skip-llvm-build \
####  --use-system-cmake \
####  2>&1 | tee $OUTPUT/rust_build-${PRGNAM}.log
####
##### Ensure that only this new rust is used, ignoring the system version:
####MYRUST_PATH="$TMP/tmp-$PRGNAM/${SRCNAM}-${SRCVER}/third_party/rust-toolchain"
####export PATH="$MYRUST_PATH:$PATH"
####