#!/bin/bash
#
# Install script for SystemTap
# Builds in $PREFIX/src and installs to $PREFIX

P=stap-install
ELFUTILS_V=0.141
SYSTEMTAP_V=0.9.8
PREFIX=/opt/stap

EXIT_SUCCESS=0
EXIT_FAILURE=-1

# Basic argument parser
while [ "$1" != "" ]; do
	case "$1" in
		-v)		export SYSTEMTAP_V=$2; shift 2;;
		--systemtap-v)  export SYSTEMTAP_V=$2; shift 2;;
		--elfutils-v)   export ELFUTILS_V=$2; shift 2;;
		*)		echo Unrecognised option: $1; shift;;
	esac
done
ELFUTILS=elfutils-$ELFUTILS_V.tar.bz2
SYSTEMTAP=systemtap-$SYSTEMTAP_V.tar.gz

# Check if SystemTap itself has already been built
if [ -e "$PREFIX/bin/stap" ]; then
	echo SystemTap already installed to $PREFIX
	exit $EXIT_SUCCESS
fi

# Make sure path is ok
GPP=`which g++`
if [ "$GPP" = "" ]; then
	echo g++ not available
	exit $EXIT_FAILURE
fi
if [ "$STAP_PATH" = "" ]; then
	export STAP_PATH="$PATH"
fi

# Build SystemTap
mkdir -p $PREFIX/src/systemtap-install
cd $PREFIX/src/systemtap-install

tar -tjf $ELFUTILS 2> /dev/null > /dev/null || rm -f $ELFUTILS
tar -tzf $SYSTEMTAP 2> /dev/null > /dev/null || rm -f $SYSTEMTAP

# Download elfutils tarball if necessary
if [ ! -f $ELFUTILS ]; then
	TARBALL="https://fedorahosted.org/releases/e/l/elfutils/$ELFUTILS"
	echo "Downloading sources ($TARBALL) ..."
	wget -q "$TARBALL" -O "$ELFUTILS"
	if [ $? -ne 0 ]; then
		echo "Failed to download from authorative location"
		exit $EXIT_FAILURE
	fi
fi

# Download systemtap tarball if necessary
if [ ! -f $SYSTEMTAP ]; then
	TARBALL="http://sourceware.org/systemtap/ftp/releases/$SYSTEMTAP"
	echo "Downloading sources ($TARBALL) ..."
	wget -q "$TARBALL" -O "$SYSTEMTAP"
	if [ $? -ne 0 ]; then
		echo "Failed to download from authorative location"
		exit $EXIT_FAILURE
	fi
fi

echo "Deleting old sources ..."
rm -rf elfutils-$ELFUTILS_V

echo "Extracting sources ..."
tar jxf $ELFUTILS
tar zxf $SYSTEMTAP

echo "Building system tap ..."
(
	PATH="$STAP_PATH:$PATH"
	cd systemtap-$SYSTEMTAP_V
	./configure --prefix=$PREFIX --with-elfutils=../elfutils-$ELFUTILS_V
	make || exit $EXIT_FAILURE

	make install || exit $EXIT_FAILURE  

) || exit "$?"

exit $EXIT_SUCCESS