#!/usr/bin/sh

# This is a script to switch the symlinks in a GTS gcc's plugin

# directory so that they select either the GTS-annobin provided

# plugin or the GTS-gcc provided plugin.

# Author: Nick Clifton  <nickc@redhat.com>

# Copyright (c) 2021-2022 Red Hat.

#

# This is free software; you can redistribute it and/or modify it

# under the terms of the GNU General Public License as published

# by the Free Software Foundation; either version 2, or (at your

# option) any later version.

# It is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# Usage:

#   gts-annobin-plugin-select scl_root

#

# Set this variable to non-zero to enable the generation of debugging

# messages.

debug=0

if test "x$1" = "x" ;

then

    if [ $debug -eq 1 ]

    then

	echo "  gts-annobin-plugin-select: Must provide a root directory"

    fi

    exit 1

else

    scl_root=$1

fi

# This script is similar to the redhat-annobin-plugin-select.sh script which

# is part of the redhat-rpm-config package.  That scripts decides between two

# versions of the annobin plugin for the system compiler and stores it choice

# in a symlink in the /usr/lib/rpm/redhat directory.  The choice eventually

# resolves into the system gcc attempting to load either a plugin called

# annobin.so or a plugin called gcc-annobin.so.

# In a GTS environment the choice made by redhat-annobin-plugin-select.sh

# might not be appropriate (or even possible).  The choice cannot be changed

# because the system compilation environment must remain instact.  So instead

# the GTS versions of gcc and annobin install plugins called gts-annobin.so

# and gts-gcc-annobin.so (into the GTS gcc's plugin directory) and this script

# creates a pair of symlinks called annobin.so and gcc-annobin.so.  In this

# way the decision made by redhat-annobin-plugin-select.sh is overridden

# without affecting any system files.

# We cannot be sure that this script will run inside a GTS enabled shell,

# so we have to use absolute paths.

gts_gcc=$scl_root/usr/bin/gcc

if [ ! -x $gts_gcc ]

then

    if [ $debug -eq 1 ]

    then

	echo "  gts-annobin-plugin-select: Could not find gcc.  Expected: $gts_gcc"

    fi

    exit 0

fi

# This is where the annobin package stores the information on the version

# of gcc that built the annobin plugin.

aver=`$gts_gcc --print-file-name=plugin`/annobin-plugin-version-info

# This is where the gcc package stores its version information.

gver=`$gts_gcc --print-file-name=rpmver`

aplugin=`$gts_gcc --print-file-name=plugin`/gts-annobin.so.0.0.0

gplugin=`$gts_gcc --print-file-name=plugin`/gts-gcc-annobin.so.0.0.0

install_annobin_version=0

install_gcc_version=0

if [ -f $aplugin ]

then

    if [ -f $gplugin ]

    then

	if [ $debug -eq 1 ]

	then

	    echo "  gts-annobin-plugin-select: Both plugins exist, checking version information"

	fi

	if [ -f $gver ]

	then

	    if [ -f $aver ]

	    then

		if [ $debug -eq 1 ]

		then

		    echo "  gts-annobin-plugin-select: Both plugin version files exist - comparing..."

		fi

		# Get the first line from the version info files.  This is just in

		# case there are extra lines in the files.

		avers=`head --lines=1 $aver`

		gvers=`head --lines=1 $gver`

		if [ $debug -eq 1 ]

		then

		    echo "  gts-annobin-plugin-select: Annobin plugin built by gcc $avers"

		    echo "  gts-annobin-plugin-select: GCC     plugin built by gcc $gvers"

		fi

		# If both plugins were built by the same version of gcc then select

		# the one from the annobin package (in case it is built from newer

		# sources).  If the plugin builder versions differ, select the gcc

		# built version instead.  This assumes that the gcc built version

		# always matches the installed gcc, which should be true.

		if [ $avers = $gvers ]

		then

		    if [ $debug -eq 1 ]

		    then

			echo "  gts-annobin-plugin-select: Both plugins built by the same compiler - using annobin-built plugin"

		    fi

		    install_annobin_version=1

		else

		    if [ $debug -eq 1 ]

		    then

			echo "  gts-annobin-plugin-select: Versions differ - using gcc-built plugin"

		    fi

		    install_gcc_version=1

		fi

	    else

		if [ $debug -eq 1 ]

		then

		    echo "  gts-annobin-plugin-select: Annobin version file does not exist, using gcc-built plugin"

		fi

		install_gcc_version=1

	    fi

	else

	    if [ -f $aver ]

	    then

		# FIXME: This is suspicious.  If the installed GCC does not supports plugins

		# then enabling the annobin plugin will not work.

		if [ $debug -eq 1 ]

		then

		    echo "  gts-annobin-plugin-select: GCC plugin version file does not exist, using annobin-built plugin"

		fi

		install_annobin_version=1

	    else

		if [ $debug -eq 1 ]

		then

		    echo "  gts-annobin-plugin-select: Neither version file exists - playing safe and using gcc-built plugin"

		    echo "  gts-annobin-plugin-select: Note: expected to find $aver and/or $gver"

		fi

		install_gcc_version=1

	    fi

	fi

    else

	if [ $debug -eq 1 ]

	then

	    echo "  gts-annobin-plugin-select: Only the annobin plugin exists - using that"

	fi

	install_annobin_version=1

    fi

else

    if [ -f $gplugin ]

    then

	if [ $debug -eq 1 ]

	then

	    echo "  gts-annobin-plugin-select: Only the gcc plugin exists - using that"

	fi

	install_gcc_version=1

    else

	aplugin=`$gts_gcc --print-file-name=plugin`/annobin.so.0.0.0

	if [ -f $aplugin ]

	then

	    if [ $debug -eq 1 ]

	    then

		echo "  gts-annobin-plugin-select: Original annobin plugin exists - renaming"

		echo "  gts-annobin-plugin-select: Using renamed original annobin plugin"

	    fi

	    pushd `$gts_gcc --print-file-name=plugin` > /dev/null

	    mv annobin.so.0.0.0 gts-annobin.so.0.0.0

	    popd > /dev/null

	    install_annobin_version=1

	else

	    if [ $debug -eq 1 ]

	    then

		echo "  gts-annobin-plugin-select: Neither plugin exists - playing safe and not changing anything"

		echo "  gts-annobin-plugin-select: Note: expected to find $aplugin and/or $gplugin"

	    fi

	fi

    fi

fi

if [ $install_annobin_version -eq 1 ]

then

    if [ $debug -eq 1 ]

    then

	echo "  gts-annobin-plugin-select: Setting symlinks for the annobin version of the plugin"

    fi

    pushd `$gts_gcc --print-file-name=plugin` > /dev/null

    rm -f gcc-annobin.so.0.0.0 annobin.so.0.0.0 gcc-annobin.so annobin.so

    ln -s gts-annobin.so.0.0.0 annobin.so

    ln -s gts-annobin.so.0.0.0 gcc-annobin.so

    ln -s gts-annobin.so.0.0.0 annobin.so.0.0.0

    ln -s gts-annobin.so.0.0.0 gcc-annobin.so.0.0.0

    popd > /dev/null

else if [ $install_gcc_version -eq 1 ]

then

    if [ $debug -eq 1 ]

    then

	echo "  gts-annobin-plugin-select: Setting symlinks for the gcc version of the plugin"

    fi

    pushd `$gts_gcc --print-file-name=plugin` > /dev/null

    rm -f gcc-annobin.so.0.0.0     annobin.so.0.0.0 gcc-annobin.so annobin.so

    ln -s gts-gcc-annobin.so.0.0.0 annobin.so

    ln -s gts-gcc-annobin.so.0.0.0 gcc-annobin.so

    ln -s gts-gcc-annobin.so.0.0.0 annobin.so.0.0.0

    ln -s gts-gcc-annobin.so.0.0.0 gcc-annobin.so.0.0.0

    popd > /dev/null

else

    if [ $debug -eq 1 ]

    then

	echo "  gts-annobin-plugin-select: NOT CHANGING SYMLINKS"

    fi

fi

fi