version.h: dynamically create version number based on git

When building the source from a checked out tag, eg v1.15, VERSION will
equal v1.15.  However, when building from anything other than a tagged
version, you get 'v1.15-4-g50432d5-dirty' meaning I was 4 patches in
front of v1.15, particularly '50432d5' was my current HEAD, and I had
uncommited changes, '-dirty'.

Very useful for folks submitting bug reports on versions they compiled
themselves.

Signed-off-by: Jason Cooper <jason@lakedaemon.net>

.gitignore

@@ -6,3 +6,4 @@ sslh-fork
 sslh-select
 sslh.8.gz
 tags
+version.h

Makefile

@@ -1,6 +1,6 @@
 # Configuration
 
-VERSION="1.15"
+VERSION=$(shell ./genver.sh -r)
 USELIBCONFIG=1	# Use libconfig? (necessary to use configuration files)
 USELIBWRAP=	# Use libwrap?
 COV_TEST= 	# Perform test coverage?
@@ -34,17 +34,19 @@ endif
 all: sslh $(MAN) echosrv
 
 .c.o: *.h
-	$(CC) $(CFLAGS) -D'VERSION=$(VERSION)' -c $<
+	$(CC) $(CFLAGS) -c $<
 
+version.h:
+	./genver.sh >version.h
 
 sslh: $(OBJS) sslh-fork sslh-select
 
-sslh-fork: $(OBJS) sslh-fork.o Makefile common.h
-	$(CC) $(CFLAGS) -D'VERSION=$(VERSION)' -o sslh-fork sslh-fork.o $(OBJS) $(LIBS)
+sslh-fork: $(OBJS) sslh-fork.o Makefile common.h version.h
+	$(CC) $(CFLAGS) -o sslh-fork sslh-fork.o $(OBJS) $(LIBS)
 	#strip sslh-fork
 
-sslh-select: $(OBJS) sslh-select.o Makefile common.h 
-	$(CC) $(CFLAGS) -D'VERSION=$(VERSION)' -o sslh-select sslh-select.o $(OBJS) $(LIBS)
+sslh-select: $(OBJS) sslh-select.o Makefile common.h version.h
+	$(CC) $(CFLAGS) -o sslh-select sslh-select.o $(OBJS) $(LIBS)
 	#strip sslh-select
 
 echosrv: $(OBJS) echosrv.o

common.h

@@ -27,10 +27,7 @@
 #include <libgen.h>
 #include <time.h>
 #include <getopt.h>
-
-#ifndef VERSION
-#define VERSION "v?"
-#endif
+#include "version.h"
 
 #define CHECK_RES_DIE(res, str) \
     if (res == -1) {    \

genver.sh

@@ -0,0 +1,33 @@
+#!/bin/sh
+
+if [ ${#} -eq 1 ] && [ "x$1" == "x-r" ]; then
+	# release text only
+	QUIET=1
+else
+	QUIET=0
+fi
+
+if head=`git rev-parse --verify HEAD 2>/dev/null`; then
+
+	if [ $QUIET -ne 1 ]; then
+		printf "#ifndef _VERSION_H_ \n"
+		printf "#define _VERSION_H_ \n\n"
+		printf "#define VERSION \""
+	fi
+
+	# generate the version info based on the tag
+	(git describe --tags || git --describe || git describe --all --long) \
+		2>/dev/null | tr -d '\n'
+
+	# Are there uncommitted changes?
+	git update-index --refresh --unmerged > /dev/null
+	if git diff-index --name-only HEAD | grep -v "^scripts/package" \
+	    | read dummy; then
+		printf '%s' -dirty
+	fi
+
+	if [ $QUIET -ne 1 ]; then
+		printf "\"\n"
+		printf "\n#endif\n"
+	fi
+fi