#!/bin/bash
# $Id: google-go-lang.SlackBuild,v 1.6 2023/07/03 18:47:37 root Exp root $
# Copyright 2012, 2013, 2014, 2015, 2016, 2017, 2018  Vincent Batts
# Copyright 2012 Eric Schultz
# Copyright 2022, 2023  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.
# -----------------------------------------------------------------------------
#
# Slackware SlackBuild script 
# ===========================
# By:          Eric Hameleers <alien@slackware.com>
# For:         google-go-lang
# Descr:       Google's Go Language kit with gc tool chain
# URL:         http://golang.org
# Build needs: go >= 1.17 (gcc11-go is too old since it offers go1.16)
# Needs:       
# Changelog:   
# 1.17.5-1:    04/jan/2022 by Eric Hameleers <alien@slackware.com>
#              * Initial build.
# 1.19.2-1:    12/oct/2022 by Eric Hameleers <alien@slackware.com>
#              * Update.
# 1.19.4-1:    07/dec/2022 by Eric Hameleers <alien@slackware.com>
#              * Update.
# 1.20.5-1:    03/jul/2023 by Eric Hameleers <alien@slackware.com>
#              * Update.
# 
# Run 'sh google-go-lang.SlackBuild' to build a Slackware package.
# The package (.t?z) and .txt file as well as build logs are created in /tmp .
# Install the package using 'installpkg' or 'upgradepkg --install-new'.
#
# -----------------------------------------------------------------------------

PRGNAM=google-go-lang
SRCNAM=go
VERSION=${VERSION:-"1.20.5"}
BUILD=${BUILD:-1}
NUMJOBS=${NUMJOBS:-" -j$(nproc) "}
TAG=${TAG:-alien}

DOCS="*.md LICENSE PATENTS VERSION"

# 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}

SOURCE[0]="$SRCDIR/${SRCNAM}${VERSION}.src.tar.gz"
SRCURL[0]="https://golang.org/dl/${SRCNAM}${VERSION}.src.tar.gz"

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

# Automatically determine the architecture we're building on:
if [ -z "$ARCH" ]; then
  case "$(uname -m)" in
  i?86) ARCH=i586 ;;
    arm*) readelf /usr/bin/file -A | egrep -q "Tag_CPU.*[4,5]" && ARCH=arm || ARCH=armv7hl ;;
    # Unless $ARCH is already set, use uname -m for all other archs:
    *) ARCH=$(uname -m) ;;
  esac
  export ARCH
fi
# Set CFLAGS/CXXFLAGS and LIBDIRSUFFIX:
case "$ARCH" in
  i?86)      SLKCFLAGS="-O2 -march=${ARCH} -mtune=i686"
             SLKLDFLAGS=""; LIBDIRSUFFIX=""
             export GOARCH="386"
             ;;
  x86_64)    SLKCFLAGS="-O2 -fPIC"
             SLKLDFLAGS="-L/usr/lib64"; LIBDIRSUFFIX="64"
             export GOARCH="amd64"
             ;;
  armv7hl)   SLKCFLAGS="-O2 -march=armv7-a -mfpu=vfpv3-d16"
             SLKLDFLAGS=""; LIBDIRSUFFIX=""
             export GOARCH="arm"
             # Can be '5' of '6' as well, to use soft instead of hw float:
             export GOARM="7"
             ;;
  *)         SLKCFLAGS=${SLKCFLAGS:-"-O2"}
             SLKLDFLAGS=${SLKLDFLAGS:-""}; LIBDIRSUFFIX=${LIBDIRSUFFIX:-""}
             export GOARCH="386"
             ;;
esac

case "$ARCH" in
    arm*)    TARGET=$ARCH-slackware-linux-gnueabi ;;
    *)       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

# 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 "++"

# We work with go directly in the package directory:
mkdir -p $PKG/usr/lib${LIBDIRSUFFIX}/go${VERSION}
cd $PKG/usr/lib${LIBDIRSUFFIX}/go${VERSION}
echo "Extracting the source archive(s) for $PRGNAM..."
tar -xvf ${SOURCE[0]}
cd ${SRCNAM}
chown -R root:root .
chmod -R u+w,go+r-w,a+rX-st .

echo Building ...
# As of >= go1.5, the cross-compiler does not need to be bootstrapped, so the
# compiler needs only be compiled for the host OS, which it detects.
unset GOBIN GOPATH GOOS GOARCH
# This needs an installed version of google-g-lang since version 1.20:
export GOROOT_BOOTSTRAP="$GOROOT"

# Default GOROOT is parent directory of all.bash, i.e. the current directory.
# Defining it here means we can use it below when building shared libraries:
export GOROOT="$(pwd)"
export GOROOT_FINAL="/usr/lib${LIBDIRSUFFIX}/go${VERSION}/go"

cd src
  echo "-- Compiling go${VERSION} suite using bootstrap ${GOROOT_BOOTSTRAP} ..."
  LC_ALL=C ./make.bash \
    2>&1 | tee $OUTPUT/make-${PRGNAM}.log
  # As of go1.5, golang supports shared libraries, so generate them for use.
  echo "-- Installing go${VERSION} suite..."
  $GOROOT/bin/go install -buildmode=shared std \
    2>&1 | tee $OUTPUT/install-${PRGNAM}.log
cd - 1>/dev/null

# Remove Go build cache:
rm -rf pkg/obj/go-build/*

# Remove the doc Makefile:
rm -f doc/Makefile

# Add profile scripts for go:
mkdir -p $PKG/etc/profile.d
cat << EOT > $PKG/etc/profile.d/go.csh
#!/bin/csh
setenv GOROOT ${GOROOT_FINAL}
setenv PATH \${GOROOT}/bin:\${PATH}
EOT
chmod 0755 $PKG/etc/profile.d/go.csh
cat << EOT > $PKG/etc/profile.d/go.sh
#!/bin/sh
export GOROOT="${GOROOT_FINAL}"
export PATH="\${GOROOT}/bin:\${PATH}"
EOT
chmod 0755 $PKG/etc/profile.d/go.sh

# Add documentation:
mkdir -p $PKG/usr/doc/$PRGNAM-$VERSION
cp -a $DOCS $PKG/usr/doc/$PRGNAM-$VERSION || true
cat $SRCDIR/$(basename $0) > $PKG/usr/doc/$PRGNAM-$VERSION/$PRGNAM.SlackBuild
chown -R root:root $PKG/usr/doc/$PRGNAM-$VERSION
find $PKG/usr/doc -type f -exec chmod 644 {} \;

# Compress the man page(s):
if [ -d $PKG/usr/man ]; then
  find $PKG/usr/man -type f -name "*.?" -exec gzip -9f {} \;
  for i in $(find $PKG/usr/man -type l -name "*.?") ; do ln -s $( readlink $i ).gz $i.gz ; rm $i ; done
fi

# Strip binaries (if any):
find $PKG | xargs file | grep -e "executable" -e "shared object" | grep ELF \
  | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || true

# Add a package description:
mkdir -p $PKG/install
cat $SRCDIR/slack-desc > $PKG/install/slack-desc

# Build the package:
cd $PKG
makepkg --linkadd y --chown n $OUTPUT/${PRGNAM}-${VERSION}-${ARCH}-${BUILD}${TAG}.${PKGTYPE:-txz} 2>&1 | tee $OUTPUT/makepkg-${PRGNAM}.log
cd $OUTPUT
md5sum ${PRGNAM}-${VERSION}-${ARCH}-${BUILD}${TAG}.${PKGTYPE:-txz} > ${PRGNAM}-${VERSION}-${ARCH}-${BUILD}${TAG}.${PKGTYPE:-txz}.md5
cd -
cat $PKG/install/slack-desc | grep "^${PRGNAM}" > $OUTPUT/${PRGNAM}-${VERSION}-${ARCH}-${BUILD}${TAG}.txt

# Restore the original umask:
umask ${_UMASK_}