PR6393: git version tagging at build time

2008-04-10  Frank Ch. Eigler  <fche@elastic.org>

	PR 6393.
	* git_version.sh: New file, copied from radeonhd.
	* configure.ac: No longer generate $builddir/SNAPSHOT.
	* Makefile.am: Generate $builddir/git_version.h.
	(EXTRA_DIST): Add git_version.h and git_version.sh.
	* main.cxx (version): Print generated GIT_MESSAGE therefrom.
	* Makefile.in, configure: Regenerated.

1 files changed, 348 insertions, 0 deletions

diff --git a/git_version.sh b/git_version.sh
new file mode 100755
index 00000000..69eb0f24
--- /dev/null
+++ b/git_version.sh
@@ -0,0 +1,348 @@
+#!/bin/sh
+#
+# Generate some basic versioning information which can be piped to a header.
+#
+# Copyright (c) 2006-2007 Luc Verhaegen <libv@skynet.be>
+# Copyright (C) 2007 Hans Ulrich Niedermann <hun@n-dimensional.de>
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# the rights to use, copy, modify, merge, publish, distribute, sublicense,
+# and/or sell copies of the Software, and to permit persons to whom the
+# Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+# THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+# OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+# ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+# OTHER DEALINGS IN THE SOFTWARE.
+#
+# This script is based on the one written for xf86-video-unichrome by
+# Luc Verhaegen, but was rewritten almost completely by Hans Ulrich
+# Niedermann. The script contains a few bug fixes from Egbert Eich,
+# Matthias Hopf, Joerg Sonnenberger, and possibly others.
+#
+# The author thanks the nice people on #git for the assistance.
+#
+# Simple testing of this script:
+#   /sbin/busybox sh git_version.sh --example > moo.c \
+#     && gcc -Wall -Wextra -Wno-unused -o moo moo.c \
+#     && ./moo
+#   (bash should also do)
+#
+# For how to hook this up to your automake- and/or imake-based build
+# system, best take a look at how the RadeonHD.am and/or RadeonHD.tmpl
+# work in the xf86-video-radeonhd build system. For non-recursive make,
+# you can probably make things a little bit simpler.
+#
+# KNOWN BUGS:
+#  * Uses hyphenated ("git-foo-bar") program names, which git upstream
+#    have declared deprecated.
+#
+
+# Help messages
+USAGE="[<option>...]"
+LONG_USAGE="\
+Options:
+  -h, --help             Print this help message.
+
+  -k, --keep-if-no-repo  Keep old output file if no git repo found.
+  -o, --output FILENAME  Set output file name.
+  -q, --quiet            Quiet output.
+  -s, --srcdir DIRNAME   Set source tree dir name.
+  -x, --example          Print complete example program."
+
+# The caller may have set these for us
+SED="${SED-sed}"
+
+# Initialize
+working_dir="$(pwd)"
+
+# Who am I?
+self="$(basename "$0")"
+
+# Defaults
+ifndef_symbol="GIT_VERSION_H"
+outfile="-"
+print_example=false
+keep_if_no_repo=no
+quiet=false
+srcdir="$(pwd)"
+
+# Parse command line parameter, affecting defaults
+while [ "x$1" != "x" ]
+do
+    case "$1" in
+        -x|--example)
+            print_example=:
+            ;;
+        -o|--output)
+            if shift; then
+                outfile="$1"
+                if [ "x$outfile" = "x-" ]; then
+                    : # keep default ifndef_symbol
+                else
+                    ifndef_symbol=`basename "$outfile" | $SED 's|\.|_|g; s|[^A-Za-z0-9_]||g' | tr a-z A-Z`
+                fi
+            else
+                echo "$self: Fatal: \"$1\" option requires parameter." >&2
+                exit 1
+            fi
+            ;;
+        -q|--quiet)
+            quiet=:
+            ;;
+        -h|--help)
+            echo "Usage: ${self} $USAGE"
+            [ -n "$LONG_USAGE" ] && echo "$LONG_USAGE"
+            exit
+            ;;
+        -k|--keep-if-no-repo)
+            keep_if_no_repo=yes
+            ;;
+	-s|--srcdir)
+	    if shift; then
+		if test -d "$1"; then
+		    srcdir="$1"
+		else
+		    echo "$self: Fatal: \"$1\" not a directory." >&2
+		    exit 1
+		fi
+	    else
+		echo "$self: Fatal: \"$1\" option requires directory parameter." >&2
+		exit 1
+	    fi
+	    ;;
+        *)
+            echo "$self: Fatal: Invalid command line paramenter: \"$1\"" >&2
+            exit 1
+            ;;
+    esac
+    shift
+done
+
+# If not printing to stdout, redirect stdout to output file
+rename_new_output=false
+if [ "x$outfile" = "x-" ]
+then
+    : # keep using stdout
+else
+    exec 1> "${outfile}.new"
+fi
+
+# Done with creating output files, so we can change to source dir
+abs_srcdir="$(cd "$srcdir" && pwd)"
+cd "$srcdir"
+
+# Write program header
+cat<<EOF
+/*
+ * Basic versioning gathered from the git repository.
+ * Automatically generated by $0.
+ */
+
+#ifndef ${ifndef_symbol}
+#define ${ifndef_symbol} 1
+
+/* whether this is a dist tarball or not */
+#undef GIT_IS_DIST
+
+EOF
+
+# Detect git tools (should work with old and new git versions)
+git_found=yes
+for git_tool in git-symbolic-ref git-rev-parse git-diff-files git-diff-index git
+do
+    if [ x`which $git_tool 2>/dev/null` = "x" ]; then
+        git_found="'$git_tool' not found"
+        break
+    fi
+done
+
+# Determine git specific defines
+unset git_errors ||:
+if [ "x$git_found" = "xyes" ]; then
+    git_version=`git --version`
+    if [ "x$git_version" = "x" ]; then
+        git_errors="${git_errors+${git_errors}; }error running 'git --version'"
+    fi
+fi
+
+git_repo=no
+# "git-rev-parse --git-dir" since git-0.99.7
+git_repo_dir="$(git-rev-parse --git-dir 2> /dev/null || true)"
+abs_repo_dir="$(cd "$git_repo_dir" && pwd)"
+# Only accept the found git repo iff it is in our top srcdir, as determined
+# by comparing absolute pathnames creaged by running pwd in the respective dir.
+if [ "x$git_repo_dir" != "x" ] && [ "x${abs_repo_dir}" = "x${abs_srcdir}/.git" ]; then
+    git_repo=yes
+    if [ "x$git_found" = "xyes" ]; then
+        # git-1.4 and probably earlier understand "git-rev-parse HEAD"
+        git_shaid=`git-rev-parse HEAD | $SED -n 's/^\(.\{8\}\).*/\1/p'`
+        if [ "x$git_shaid" = "x" ]; then
+            git_errors="${git_errors+${git_errors}; }error running 'git-rev-parse HEAD'"
+        fi
+        # git-1.4 and probably earlier understand "git-symbolic-ref HEAD"
+        git_branch=`git-symbolic-ref HEAD | $SED -n 's|^refs/heads/||p'`
+        if [ "x$git_branch" = "x" ]; then
+            # This happens, is OK, and "(no branch)" is what "git branch" prints.
+            git_branch="(no branch)"
+        fi
+        git_dirty=yes
+        # git-1.4 does not understand "git-diff-files --quiet"
+        # git-1.4 does not understand "git-diff-index --cached --quiet HEAD"
+        if [ "x$(git-diff-files)" = "x" ] && [ "x$(git-diff-index --cached HEAD)" = "x" ]; then
+            git_dirty=no
+        fi
+    fi
+fi
+
+# Write git specific defines
+if [ "x$git_errors" = "x" ]; then
+    echo "/* No errors occured while running git */"
+    echo "#undef GIT_ERRORS"
+else
+    echo "/* Some errors occured while running git */"
+    echo "#define GIT_ERRORS \"${git_errors}\""
+fi
+echo ""
+
+if [ "x$git_found" = "xyes" ]; then
+    echo "/* git utilities found */"
+    echo "#undef GIT_NOT_FOUND"
+    echo "#define GIT_VERSION \"${git_version}\""
+else
+    echo "/* git utilities not found */"
+    echo "#define GIT_NOT_FOUND \"${git_found}\""
+    echo "#undef GIT_VERSION"
+fi
+echo ""
+
+if [ "x$git_repo" = "xno" ]; then
+    echo "/* No git repo found, probably building from dist tarball */"
+    echo "#undef GIT_REPO"
+else
+    echo "/* git repo found */"
+    echo "#define GIT_REPO 1"
+    echo ""
+    if [ "x$git_found" = "xyes" ]; then
+        echo "/* Git SHA ID of last commit */"
+        echo "#define GIT_SHAID \"${git_shaid}\""
+        echo ""
+
+        echo "/* Branch this tree is on */"
+        echo "#define GIT_BRANCH \"$git_branch\""
+        echo ""
+
+        # Any uncommitted changes we should know about?
+        # Or technically: Are the working tree or index dirty?
+        if [ "x$git_dirty" = "xno" ]; then
+            echo "/* SHA-ID uniquely defines the state of this code */"
+            echo "#undef GIT_DIRTY"
+        else
+            echo "/* Local changes might be breaking things */"
+            echo "#define GIT_DIRTY 1"
+        fi
+    fi
+fi
+
+# Define a few immediately useful message strings
+cat<<EOF
+
+/* Define GIT_MESSAGE such that
+ *    printf("%s: built from %s", argv[0], GIT_MESSAGE);
+ * forms a proper sentence.
+ */
+
+#ifdef GIT_DIRTY
+# define GIT_DIRTY_MSG " + changes"
+#else /* !GIT_DIRTY */
+# define GIT_DIRTY_MSG ""
+#endif /* GIT_DIRTY */
+
+#ifdef GIT_ERRORS
+# define GIT_ERROR_MSG " with error: " GIT_ERRORS
+#else /* !GIT_ERRORS */
+# define GIT_ERROR_MSG ""
+#endif /* GIT_ERRORS */
+
+#ifdef GIT_IS_DIST
+# define GIT_DIST_MSG "dist of "
+#else /* !GIT_IS_DIST */
+# define GIT_DIST_MSG ""
+#endif /* GIT_IS_DIST */
+
+#ifdef GIT_REPO
+# ifdef GIT_NOT_FOUND
+#  define GIT_MESSAGE GIT_DIST_MSG "git sources without git: " GIT_NOT_FOUND
+# else /* !GIT_NOT_FOUND */
+#  define GIT_MESSAGE \\
+       GIT_DIST_MSG \\
+       "git branch " GIT_BRANCH ", " \\
+       "commit " GIT_SHAID GIT_DIRTY_MSG \\
+       GIT_ERROR_MSG
+# endif /* GIT_NOT_FOUND */
+#else /* !GIT_REPO */
+# define GIT_MESSAGE GIT_DIST_MSG "non-git sources" GIT_ERROR_MSG
+#endif /* GIT_REPO */
+
+#endif /* ${ifndef_symbol} */
+EOF
+
+# Example program
+if "$print_example"
+then
+    cat<<EOF
+
+/* example program demonstrating the use of git_version.sh output */
+#include <stdio.h>
+#include <string.h>
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+int main(int argc, char *argv[])
+{
+    const char *const idx = strrchr(argv[0], '/');
+    const char *const prog = (idx)?(idx+1):(argv[0]);
+#ifdef PACKAGE_VERSION
+    printf("%s: version %s, built from %s\n", prog, PACKAGE_VERSION, GIT_MESSAGE);
+#elif defined(GIT_USED)
+    printf("%s: built from %s\n", prog, GIT_MESSAGE);
+#endif
+    return 0;
+}
+EOF
+fi
+
+# Change back to working dir for the remaining output file manipulations.
+cd "$working_dir"
+
+# If necessary, overwrite outdated output file with new one
+if [ "x$outfile" != "x-" ]
+then
+    if [ -f "$outfile" ]; then
+        if [ "x$keep_if_no_repo" = "xyes" ] && [ "x$git_repo" = "xno" ]; then
+            "$quiet" || echo "$self: Not a git repo, keeping existing $outfile" >&2
+            rm -f "$outfile.new"
+        elif cmp "$outfile" "$outfile.new" > /dev/null; then
+            "$quiet" || echo "$self: Output is unchanged, keeping $outfile" >&2
+            rm -f "$outfile.new"
+        else
+            echo "$self: Output has changed, updating $outfile" >&2
+            mv -f "$outfile.new" "$outfile"
+        fi
+    else
+        echo "$self: Output is new file, creating $outfile" >&2
+        mv -f "$outfile.new" "$outfile"
+    fi
+fi
+
+# THE END.