#! /bin/sh

PROJECT=fips
PROJECT_BLURB="a program for monitoring performance of OpenGL applications"

# Test whether this shell is capable of parameter substring processing.
( option='a/b'; : ${option#*/} ) 2>/dev/null || {
    echo "
The shell interpreting '$0' is lacking some required features.

To work around this problem you may try to execute:

    ksh $0 $*
 or
    bash $0 $*
"
    exit 1
}

# Store original IFS value so it can be changed (and restored) in many places.
readonly DEFAULT_IFS="$IFS"

srcdir=$(dirname "$0")

# For a non-srcdir configure invocation (such as ../configure), create
# the directory structure and copy Makefiles.
if [ "$srcdir" != "." ]; then

    for dir in . $(grep "^subdirs *=" "$srcdir"/Makefile | sed -e "s/subdirs *= *//"); do
	mkdir -p "$dir"
	cp "$srcdir"/"$dir"/Makefile.local "$dir"
	cp "$srcdir"/"$dir"/Makefile "$dir"
    done
fi

# Set several defaults (optionally specified by the user in
# environment variables)
CC=${CC:-gcc}
CFLAGS=${CFLAGS:--O2}
LDFLAGS=${LDFLAGS:-}

# Set the defaults for values the user can specify with command-line
# options.
PREFIX=/usr/local

usage ()
{
    cat <<EOF
Usage: ./configure [options]...

This script configures ${PROJECT} to build on your system.

It verifies that dependencies are available, determines flags needed
to compile and link against various required libraries, and identifies
whether various system functions can be used or if locally-provided
replacements will be built instead.

Finally, it allows you to control various aspects of the build and
installation process.

First, some common variables can specified via environment variables:

	CC		The C compiler to use
	CFLAGS		Flags to pass to the C compiler
	LDFLAGS		Flags to pass when linking

Each of these values can further be controlled by specifying them
later on the "make" command line.

Additionally, various options can be specified on the configure
command line.

	--prefix=PREFIX	Install files in PREFIX [$PREFIX]

By default, "make install" will install the resulting program to
$PREFIX/bin, documentation to $PREFIX/man, etc. You can
specify an installation prefix other than $PREFIX using
--prefix, for instance:

	./configure --prefix=\$HOME

Fine tuning of some installation directories is available:

	--bindir=DIR		Install executables to DIR [PREFIX/bin]
	--libdir=DIR		Install libraries to DIR [PREFIX/lib]
	--mandir=DIR		Install man pages to DIR [PREFIX/share/man]
	--sysconfdir=DIR	Read-only single-machine data [PREFIX/etc]

Additional options are accepted for compatibility with other
configure-script calling conventions, but don't do anything yet:

	--build=<cpu>-<vendor>-<os>	Currently ignored
	--host=<cpu>-<vendor>-<os>	Currently ignored
	--infodir=DIR			Currently ignored
	--datadir=DIR			Currently ignored
	--localstatedir=DIR		Currently ignored
	--libexecdir=DIR		Currently ignored
	--disable-maintainer-mode	Currently ignored
	--disable-dependency-tracking	Currently ignored

EOF
}

# Given two absolute paths ("from" and "to"), compute a relative path
# from "from" to "to". For example:
#
#	relative_path /foo/bar/baz /foo/qux -> ../../qux
relative_path ()
{
    if [ $# -ne 2 ] ; then
	echo "Internal error: relative_path requires exactly 2 arguments"
	exit 1;
    fi

    from="$1"
    to="$2"

    # Handle trivial case up-front
    if [ "$from" = "$to" ] ; then
	echo ""
    else
	shared="$from"
	relative=""

	while [ "${to#$shared}" = "$to" ] && [ "$shared" != "." ] ; do
	    shared="$(dirname $shared)"
	    relative="..${relative:+/${relative}}"
	done

	echo "${relative:-.}${to#$shared}"
    fi
}

# Parse command-line options
for option; do
    if [ "${option}" = '--help' ] ; then
	usage
	exit 0
    elif [ "${option%%=*}" = '--prefix' ] ; then
	PREFIX="${option#*=}"
    elif [ "${option%%=*}" = '--bindir' ] ; then
	BINDIR="${option#*=}"
    elif [ "${option%%=*}" = '--libdir' ] ; then
	LIBDIR="${option#*=}"
    elif [ "${option%%=*}" = '--mandir' ] ; then
	MANDIR="${option#*=}"
    elif [ "${option%%=*}" = '--sysconfdir' ] ; then
	SYSCONFDIR="${option#*=}"
    elif [ "${option%%=*}" = '--build' ] ; then
	true
    elif [ "${option%%=*}" = '--host' ] ; then
	true
    elif [ "${option%%=*}" = '--infodir' ] ; then
	true
    elif [ "${option%%=*}" = '--datadir' ] ; then
	true
    elif [ "${option%%=*}" = '--localstatedir' ] ; then
	true
    elif [ "${option%%=*}" = '--libexecdir' ] ; then
	true
    elif [ "${option}" = '--disable-maintainer-mode' ] ; then
	true
    elif [ "${option}" = '--disable-dependency-tracking' ] ; then
	true
    else
	echo "Unrecognized option: ${option}"
	echo "See:"
	echo "	$0 --help"
	echo ""
	exit 1
    fi
done

cat <<EOF
Welcome to ${PROJECT}, ${PROJECT_BLURB}

We hope that the process of building and installing ${PROJECT} is quick
and smooth.

If anything goes wrong in the configure process, you can override any
decisions it makes by manually editing the Makefile.config file that
it creates. Also please do as much as you can to figure out what could
be different on your machine compared to those of the ${PROJECT}
developers. Then, please email those details to the ${PROJECT} developers so
that they can hopefully make future versions of ${PROJECT} easier for you to
use.

We'll now investigate your system to verify that all required
dependencies are available:

EOF

errors=0

if pkg-config --version > /dev/null 2>&1; then
    have_pkg_config=1
else
    have_pkg_config=0
fi

printf "Checking for talloc development files... "
if pkg-config --exists talloc; then
    printf "Yes.\n"
    have_talloc=1
    talloc_cflags=$(pkg-config --cflags talloc)
    talloc_ldflags=$(pkg-config --libs talloc)
else
    printf "No.\n"
    have_talloc=0
    talloc_cflags=
    errors=$((errors + 1))
fi

printf "Checking which platform we are on... "
uname=`uname`
if [ $uname = "Darwin" ] ; then
    printf "Mac OS X.\n"
    platform=MACOSX
    linker_resolves_library_dependencies=0
elif [ $uname = "SunOS" ] ; then
    printf "Solaris.\n"
    platform=SOLARIS
    linker_resolves_library_dependencies=0
elif [ $uname = "FreeBSD" ] ; then
    printf "FreeBSD.\n"
    platform=FREEBSD
    linker_resolves_library_dependencies=0
elif [ $uname = "OpenBSD" ] ; then
    printf "OpenBSD.\n"
    platform=OPENBSD
    linker_resolves_library_dependencies=0
elif [ $uname = "Linux" ] || [ $uname = "GNU" ] ; then
    printf "$uname\n"
    platform="$uname"
    linker_resolves_library_dependencies=1
else
    printf "Unknown.\n"
    cat <<EOF

*** Warning: Unknown platform. ${PROJECT} might or might not build correctly.

EOF
fi

if [ $errors -gt 0 ]; then
    cat <<EOF

*** Error: The dependencies of ${PROJECT} could not be satisfied. You will
need to install the following packages before being able to compile
${PROJECT}:

EOF
    if [ $have_talloc -eq 0 ]; then
	echo "	The talloc library (including development files such as headers)"
	echo "	http://talloc.samba.org/"
	echo
    fi
    cat <<EOF
With any luck, you're using a modern, package-based operating system
that has all of these packages available in the distribution. In that
case a simple command will install everything you need. For example:

On Debian and similar systems:

	sudo apt-get install libtalloc-dev

Or on Fedora and similar systems:

	sudo yum install libtalloc-devel

On other systems, similar commands can be used, but the details of the
package names may be different.

EOF
    if [ $have_pkg_config -eq 0 ]; then
cat <<EOF
Note: the pkg-config program is not available. This configure script
uses pkg-config to find the compilation flags required to link against
the various libraries needed by ${PROJECT}. It's possible you simply need
to install pkg-config with a command such as:

	sudo apt-get install pkg-config
Or:
	sudo yum install pkgconfig

But if pkg-config is not available for your system, then you will need
to modify the configure script to manually set the cflags and ldflags
variables to the correct values to link against each library in each
case that pkg-config could not be used to determine those values.

EOF
    fi
cat <<EOF
When you have installed the necessary dependencies, you can run
configure again to ensure the packages can be found, or simply run
"make" to compile.

EOF
    exit 1
fi

printf "int main(void){return 0;}\n" > minimal.c

WARN_CFLAGS=""
printf "Checking for available C compiler warning flags... "
for flag in -Wall -Wextra -Wmissing-declarations; do
    if ${CC} $flag -o minimal minimal.c > /dev/null 2>&1
    then
	WARN_CFLAGS="${WARN_CFLAGS}${WARN_CFLAGS:+ }${flag}"
    fi
done
printf "\n\t${WARN_CFLAGS}\n"

rm -f minimal minimal.c

cat <<EOF

All required packages were found. You may now run the following
commands to compile and install ${PROJECT}:

	make
	sudo make install

EOF

# construct the Makefile.config
cat > Makefile.config <<EOF
# This Makefile.config was automatically generated by the ./configure
# script of ${PROJECT}. If the configure script identified anything
# incorrectly, then you can edit this file to try to correct things,
# but be warned that if configure is run again it will destroy your
# changes, (and this could happen by simply calling "make" if the
# configure script is updated).

# The top-level directory for the source, (the directory containing
# the configure script). This may be different than the build
# directory (the current directory at the time configure was run).
srcdir = ${srcdir}

configure_options = $@

# We use vpath directives (rather than the VPATH variable) since the
# VPATH variable matches targets as well as prerequisites, (which is
# not useful since then a target left-over from a srcdir build would
# cause a target to not be built in the non-srcdir build).
#
# Also, we don't use a single "vpath % \$(srcdir)" here because we
# don't want the vpath to trigger for our emacs lisp compilation,
# (unless we first find a way to convince emacs to build the .elc
# target in a directory other than the directory of the .el
# prerequisite). In the meantime, we're actually copying in the .el
# files, (which is quite ugly).
vpath %.c \$(srcdir)
vpath %.cc \$(srcdir)
vpath %.1 \$(srcdir)
vpath Makefile.% \$(srcdir)

# The C compiler to use
CC = ${CC}

# Default FLAGS for C compiler (can be overridden by user such as "make CFLAGS=-g")
CFLAGS = ${CFLAGS}

# Default FLAGS for the linker (can be overridden by user such as "make LDFLAGS=-znow")
LDFLAGS = ${LDFLAGS}

# Flags to enable warnings when using the C compiler
WARN_CFLAGS=${WARN_CFLAGS}

# The prefix to which ${PROJECT} should be installed
prefix = ${PREFIX}

# The directory to which executables should be installed
bindir = ${BINDIR:=\$(prefix)/bin}

# The directory to which libraries should be installed
libdir = ${LIBDIR:=\$(prefix)/lib}

# The directory to which man pages should be installed
mandir = ${MANDIR:=\$(prefix)/share/man}

# The directory to which read-only (configuration) files should be installed
sysconfdir = ${SYSCONFDIR:=\$(prefix)/etc}

# Supported platforms (so far) are: LINUX, MACOSX, SOLARIS, FREEBSD, OPENBSD
PLATFORM = ${platform}

# Whether the linker will automatically resolve the dependency of one
# library on another (if not, then linking a binary requires linking
# directly against both)
LINKER_RESOLVES_LIBRARY_DEPENDENCIES = ${linker_resolves_library_dependencies}

# Flags needed to compile and link against talloc
TALLOC_CFLAGS = ${talloc_cflags}
TALLOC_LDFLAGS = ${talloc_ldflags}

# Flags needed to have linker link only to necessary libraries
AS_NEEDED_LDFLAGS = ${as_needed_ldflags}

# Combined flags for compiling and linking against all of the above
CONFIGURE_CFLAGS = \$(TALLOC_CFLAGS)
CONFIGURE_LDFLAGS = \$(TALLOC_LDFLAGS)
EOF

# construct config.h
cat > config.h <<EOF
/* Generated by configure. */

/* Relative path from ${bindir} to ${libdir} */
#define BINDIR_TO_LIBFIPSDIR "$(relative_path ${BINDIR} ${LIBDIR})/fips"
EOF