#!/bin/sh
### autogen.sh - tool to help build Emacs from a repository checkout

## Copyright (C) 2011-2016 Free Software Foundation, Inc.

## Author: Glenn Morris <rgm@gnu.org>
## Maintainer: emacs-devel@gnu.org

## This file is part of GNU Emacs.

## GNU Emacs 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 3 of the License, or
## (at your option) any later version.

## GNU Emacs 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.

## You should have received a copy of the GNU General Public License
## along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.

### Commentary:

## The Emacs repository does not include the configure script (and
## associated helpers).  The first time you fetch Emacs from the repo,
## run this script to generate the necessary files.
## For more details, see the file INSTALL.REPO.

### Code:

## Tools we need:
## Note that we respect the values of AUTOCONF etc, like autoreconf does.
progs="autoconf automake"

## Minimum versions we need:
autoconf_min=`sed -n 's/^ *AC_PREREQ(\([0-9\.]*\)).*/\1/p' configure.ac`

## This will need improving if more options are ever added to the
## AM_INIT_AUTOMAKE call.
automake_min=`sed -n 's/^ *AM_INIT_AUTOMAKE(\([0-9\.]*\)).*/\1/p' configure.ac`


## $1 = program, eg "autoconf".
## Echo the version string, eg "2.59".
## FIXME does not handle things like "1.4a", but AFAIK those are
## all old versions, so it is OK to fail there.
## Also note that we do not handle micro versions.
get_version ()
{
    ## Remove eg "./autogen.sh: line 50: autoconf: command not found".
    $1 --version 2>&1 | sed -e '/not found/d' -e 's/.* //' -n -e '1 s/\([0-9][0-9\.]*\).*/\1/p'
}

## $1 = version string, eg "2.59"
## Echo the major version, eg "2".
major_version ()
{
    echo $1 | sed -e 's/\([0-9][0-9]*\)\..*/\1/'
}

## $1 = version string, eg "2.59"
## Echo the minor version, eg "59".
minor_version ()
{
    echo $1 | sed -e 's/[0-9][0-9]*\.\([0-9][0-9]*\).*/\1/'
}

## $1 = program
## $2 = minimum version.
## Return 0 if program is present with version >= minimum version.
## Return 1 if program is missing.
## Return 2 if program is present but too old.
## Return 3 for unexpected error (eg failed to parse version).
check_version ()
{
    ## Respect eg $AUTOMAKE if it is set, like autoreconf does.
    uprog=`echo $1 | sed -e 's/-/_/g' -e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/'`

    eval uprog=\$${uprog}

    [ x"$uprog" = x ] && uprog=$1

    have_version=`get_version $uprog`

    [ x"$have_version" = x ] && return 1

    have_maj=`major_version $have_version`
    need_maj=`major_version $2`

    [ x"$have_maj" != x ] && [ x"$need_maj" != x ] || return 3

    [ $have_maj -gt $need_maj ] && return 0
    [ $have_maj -lt $need_maj ] && return 2

    have_min=`minor_version $have_version`
    need_min=`minor_version $2`

    [ x"$have_min" != x ] && [ x"$need_min" != x ] || return 3

    [ $have_min -ge $need_min ] && return 0
    return 2
}

do_autoconf=false
test $# -eq 0 && do_autoconf=true
do_git=false

for arg; do
    case $arg in
      --help)
	exec echo "$0: usage: $0 [all|autoconf|git]";;
      all)
	do_autoconf=true do_git=true;;
      autoconf)
	do_autoconf=true;;
      git)
	do_git=true;;
      *)
	echo >&2 "$0: $arg: unknown argument"; exit 1;;
    esac
done


# Generate Autoconf and Automake related files, if requested.

if $do_autoconf; then

  echo 'Checking whether you have the necessary tools...
(Read INSTALL.REPO for more details on building Emacs)'

  missing=

  for prog in $progs; do

    sprog=`echo "$prog" | sed 's/-/_/g'`

    eval min=\$${sprog}_min

    echo "Checking for $prog (need at least version $min)..."

    check_version $prog $min

    retval=$?

    case $retval in
        0) stat="ok" ;;
        1) stat="missing" ;;
        2) stat="too old" ;;
        *) stat="unable to check" ;;
    esac

    echo $stat

    if [ $retval -ne 0 ]; then
        missing="$missing $prog"
        eval ${sprog}_why=\""$stat"\"
    fi

  done


  if [ x"$missing" != x ]; then

    echo '
Building Emacs from the repository requires the following specialized programs:'

    for prog in $progs; do
        sprog=`echo "$prog" | sed 's/-/_/g'`

        eval min=\$${sprog}_min

        echo "$prog (minimum version $min)"
    done


    echo '
Your system seems to be missing the following tool(s):'

    for prog in $missing; do
        sprog=`echo "$prog" | sed 's/-/_/g'`

        eval why=\$${sprog}_why

        echo "$prog ($why)"
    done

    echo '
If you think you have the required tools, please add them to your PATH
and re-run this script.

Otherwise, please try installing them.
On systems using rpm and yum, try: "yum install PACKAGE"
On systems using dpkg and apt, try: "apt-get install PACKAGE"
Then re-run this script.

If you do not have permission to do this, or if the version provided
by your system is too old, it is normally straightforward to build
these packages from source.  You can find the sources at:

ftp://ftp.gnu.org/gnu/PACKAGE/

Download the package (make sure you get at least the minimum version
listed above), extract it using tar, then run configure, make,
make install.  Add the installation directory to your PATH and re-run
this script.

If you know that the required versions are in your PATH, but this
script has made an error, then you can simply run

autoreconf -fi -I m4

instead of this script.

Please report any problems with this script to bug-gnu-emacs@gnu.org .'

    exit 1
  fi

  echo 'Your system has the required tools.'
  echo "Running 'autoreconf -fi -I m4' ..."


  ## Let autoreconf figure out what, if anything, needs doing.
  ## Use autoreconf's -f option in case autoreconf itself has changed.
  autoreconf -fi -I m4 || exit $?

  ## Create a timestamp, so that './autogen.sh; make' doesn't
  ## cause 'make' to needlessly run 'autoheader'.
  echo timestamp > src/stamp-h.in || exit
fi


# True if the Git setup was OK before autogen.sh was run.

git_was_ok=true

if $do_git; then
    case `cp --help 2>/dev/null` in
      *--backup*--verbose*)
	cp_options='--backup=numbered --verbose';;
      *)
	cp_options='-f';;
    esac
fi


# Like 'git config NAME VALUE' but verbose on change and exiting on failure.
# Also, do not configure unless requested.

git_config ()
{
    name=$1
    value=$2

    ovalue=`git config --get "$name"` && test "$ovalue" = "$value" || {
	if $do_git; then
	    if $git_was_ok; then
		echo 'Configuring local git repository...'
		case $cp_options in
		  --backup=*)
		    cp $cp_options --force .git/config .git/config || exit;;
		esac
	    fi
	    echo "git config $name '$value'"
	    git config "$name" "$value" || exit
	fi
	git_was_ok=false
    }
}

## Configure Git, if requested.

# Check hashes when transferring objects among repositories.

git_config transfer.fsckObjects true


# Configure 'git diff' hunk header format.

git_config diff.elisp.xfuncname \
	   '^\(def[^[:space:]]+[[:space:]]+([^()[:space:]]+)'
git_config 'diff.m4.xfuncname' '^((m4_)?define|A._DEFUN(_ONCE)?)\([^),]*'
git_config 'diff.make.xfuncname' \
	   '^([$.[:alnum:]_].*:|[[:alnum:]_]+[[:space:]]*([*:+]?[:?]?|!?)=|define .*)'
git_config 'diff.shell.xfuncname' \
	   '^([[:space:]]*[[:alpha:]_][[:alnum:]_]*[[:space:]]*\(\)|[[:alpha:]_][[:alnum:]_]*=)'
git_config diff.texinfo.xfuncname \
	   '^@node[[:space:]]+([^,[:space:]][^,]+)'


# Install Git hooks.

tailored_hooks=
sample_hooks=

for hook in commit-msg pre-commit; do
    cmp build-aux/git-hooks/$hook .git/hooks/$hook >/dev/null 2>&1 ||
	tailored_hooks="$tailored_hooks $hook"
done
for hook in applypatch-msg pre-applypatch; do
    src=.git/hooks/$hook.sample
    cmp "$src" .git/hooks/$hook >/dev/null 2>&1 ||
	sample_hooks="$sample_hooks $hook"
done

if test -n "$tailored_hooks$sample_hooks"; then
    if $do_git; then
	echo "Installing git hooks..."

	if test -n "$tailored_hooks"; then
	    for hook in $tailored_hooks; do
		dst=.git/hooks/$hook
		cp $cp_options build-aux/git-hooks/$hook "$dst" || exit
		chmod a-w "$dst" || exit
	    done
	fi

	if test -n "$sample_hooks"; then
	    for hook in $sample_hooks; do
		cp $cp_options .git/hooks/$hook.sample .git/hooks/$hook || exit
		chmod a-w .git/hooks/$hook || exit
	    done
	fi
    else
	git_was_ok=false
    fi
fi

if test ! -f configure; then
    echo "You can now run '$0 autoconf'."
elif test -d .git && test $git_was_ok = false && test $do_git = false; then
    echo "You can now run '$0 git'."
elif test ! -f config.status ||
	test -n "`find src/stamp-h.in -newer config.status`"; then
    echo "You can now run './configure'."
fi

exit 0

### autogen.sh ends here