#!/bin/sh
#
# This scripts adds local version information from the version
# control systems git, mercurial (hg) and subversion (svn).
#
# If something goes wrong, send a mail the kernel build mailinglist
# (see MAINTAINERS) and CC Nico Schottelius
# <nico-linuxsetlocalversion -at- schottelius.org>.
#
#

usage() {
        echo "Usage: $0 [--save-scmversion] [srctree]" >&2
        exit 1
}

scm_only=false
srctree=.
if test "$1" = "--save-scmversion"; then
        scm_only=true
        shift
fi
if test $# -gt 0; then
        srctree=$1
        shift
fi
if test $# -gt 0 -o ! -d "$srctree"; then
        usage
fi

scm_version()
{
        local short
        short=false

        cd "$srctree"
        if test -e .scmversion; then
                cat .scmversion
                return
        fi
        if test "$1" = "--short"; then
                short=true
        fi

        # Check for git and a git repo.
        if test -d .git && head=`git rev-parse --verify --short HEAD 2>/dev/null`; then

                # If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
                # it, because this version is defined in the top level Makefile.
                if [ -z "`git describe --exact-match 2>/dev/null`" ]; then

                        # If only the short version is requested, don't bother
                        # running further git commands
                        if $short; then
                                echo "+"
                                return
                        fi
                        # If we are past a tagged commit (like
                        # "v2.6.30-rc5-302-g72357d5"), we pretty print it.
                        if atag="`git describe 2>/dev/null`"; then
                                echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'

                        # If we don't have a tag at all we print -g{commitish}.
                        else
                                printf '%s%s' -g $head
                        fi
                fi

                # Is this git on svn?
                if git config --get svn-remote.svn.url >/dev/null; then
                        printf -- '-svn%s' "`git svn find-rev $head`"
                fi

                # Update index only on r/w media
                [ -w . ] && git update-index --refresh --unmerged > /dev/null

                # Check for uncommitted changes
                if git diff-index --name-only HEAD | grep -v "^scripts/package" \
                    | read dummy; then
                        printf '%s' -dirty
                fi

                # All done with git
                return
        fi

        # Check for mercurial and a mercurial repo.
        if test -d .hg && hgid=`hg id 2>/dev/null`; then
                # Do we have an tagged version?  If so, latesttagdistance == 1
                if [ "`hg log -r . --template '{latesttagdistance}'`" == "1" ]; then
                        id=`hg log -r . --template '{latesttag}'`
                        printf '%s%s' -hg "$id"
                else
                        tag=`printf '%s' "$hgid" | cut -d' ' -f2`
                        if [ -z "$tag" -o "$tag" = tip ]; then
                                id=`printf '%s' "$hgid" | sed 's/[+ ].*//'`
                                printf '%s%s' -hg "$id"
                        fi
                fi

                # Are there uncommitted changes?
                # These are represented by + after the changeset id.
                case "$hgid" in
                        *+|*+\ *) printf '%s' -dirty ;;
                esac

                # All done with mercurial
                return
        fi

        # Check for svn and a svn repo.
        if rev=`svn info 2>/dev/null | grep '^Last Changed Rev'`; then
                rev=`echo $rev | awk '{print $NF}'`
                printf -- '-svn%s' "$rev"

                # All done with svn
                return
        fi
}

collect_files()
{
        local file res

        for file; do
                case "$file" in
                *\~*)
                        continue
                        ;;
                esac
                if test -e "$file"; then
                        res="$res$(cat "$file")"
                fi
        done
        echo "$res"
}

if $scm_only; then
        if test ! -e .scmversion; then
                res=$(scm_version)
                echo "$res" >.scmversion
        fi
        exit
fi

if test -e include/config/auto.conf; then
        . include/config/auto.conf
else
        echo "Error: kernelrelease not valid - run 'make prepare' to update it"
        exit 1
fi

# localversion* files in the build and source directory
res="$(collect_files localversion*)"
if test ! "$srctree" -ef .; then
        res="$res$(collect_files "$srctree"/localversion*)"
fi

# CONFIG_LOCALVERSION and LOCALVERSION (if set)
res="${res}${CONFIG_LOCALVERSION}${LOCALVERSION}"

# scm version string if not at a tagged commit
if test "$CONFIG_LOCALVERSION_AUTO" = "y"; then
        # full scm version string
        res="$res$(scm_version)"
else
        # append a plus sign if the repository is not in a clean
        # annotated or signed tagged state (as git describe only
        # looks at signed or annotated tags - git tag -a/-s) and
        # LOCALVERSION= is not specified
        if test "${LOCALVERSION+set}" != "set"; then
                scm=$(scm_version --short)
                res="$res${scm:++}"
        fi
fi

echo "$res"