From 80b20b17ebb48d12c285a47e2f6f3ed1130c97fd Mon Sep 17 00:00:00 2001
From: Olaf Seibert <rhialto@falu.nl>
Date: Mon, 6 Jul 2015 21:43:03 +0200
Subject: [PATCH] Add some info about git commit when printing the version.

Also modify dependency generation to be a side-effect of compilation.
It's still not quite perfect in picking up some changes (in particular
just after a commit, no files have changed but the git identification
is now different).
---
 Makefile      | 14 ++++++++++----
 macro11.c     |  2 +-
 macro11.h     | 10 +++++++++-
 make-git-info | 21 +++++++++++++++++++++
 4 files changed, 41 insertions(+), 6 deletions(-)
 create mode 100755 make-git-info

diff --git a/Makefile b/Makefile
index b2fe715..99e1b5b 100644
--- a/Makefile
+++ b/Makefile
@@ -24,7 +24,7 @@ all: macro11 dumpobj
 tags: macro11 dumpobj
 	ctags *.c *.h
 
-macro11: $(MACRO11_OBJS) Makefile
+macro11: git-info.h $(MACRO11_OBJS) Makefile
 	$(CC) $(CFLAGS) -o macro11 $(MACRO11_OBJS) -lm
 
 dumpobj: $(DUMPOBJ_OBJS) Makefile
@@ -33,9 +33,13 @@ dumpobj: $(DUMPOBJ_OBJS) Makefile
 $(MACRO11_OBJS): Makefile
 $(DUMPOBJ_OBJS): Makefile
 
+git-info.h:
+	./make-git-info
+
 clean:
 	-rm -f $(MACRO11_OBJS) $(DUMPOBJ_OBJS) macro11 dumpobj
 	-rm -f *.d
+	-rm -f git-info.h
 
 # Since the only tests we have so far are for crashes,
 # just try to assemble. Later, we will need expected/actual tests.
@@ -63,8 +67,10 @@ tests: macro11 argtests
 
 -include $(ALL_SRCS:.c=.d)
 
-%.d: %.c
-	@set -e; rm -f $@; \
+# Make .d files as side effect of compiling .c to .o
+%.d %.o: %.c
+	$(CC) $(CFLAGS) -c -o $*.o $<
+	@set -e; rm -f $*.d; \
 	    $(CC) -MM $(CPPFLAGS) $< > $@.$$$$; \
-	    sed 's,\($*\)\.o[ :]*,\1.o $@ : ,g' < $@.$$$$ > $@; \
+	    sed 's,\($*\)\.o[ :]*,\1.o \1.d : ,g' < $@.$$$$ > $*.d; \
 	    rm -f $@.$$$$
diff --git a/macro11.c b/macro11.c
index 8e10d6b..ef50f88 100644
--- a/macro11.c
+++ b/macro11.c
@@ -82,7 +82,7 @@ static void print_version(
     fprintf(strm, "macro11 - portable MACRO11 assembler for DEC PDP-11\n");
     fprintf(strm, "  Version %s\n", VERSIONSTR);
     fprintf(strm, "  Copyright 2001 Richard Krehbiel,\n");
-    fprintf(strm, "  modified 2009 by Joerg Hoppe.\n");
+    fprintf(strm, "  modified 2009 by Joerg Hoppe,\n");
     fprintf(strm, "  modified 2015 by Olaf 'Rhialto' Seibert.\n");
 }
 
diff --git a/macro11.h b/macro11.h
index 40a5621..12ac3bf 100644
--- a/macro11.h
+++ b/macro11.h
@@ -1,9 +1,17 @@
 #ifndef MACRO11_H
 #define MACRO11_H
 
-#define VERSIONSTR "0.4wip (22 May 2015)"
+#include "git-info.h"
+
+#define BASE_VERSION "0.4wip"
+
+#if defined(GIT_VERSION)
+#define VERSIONSTR BASE_VERSION" ("GIT_VERSION"\n\t"GIT_AUTHOR_DATE")"
+#else
+#define VERSIONSTR BASE_VERSION" (21 June 2015)"
 /*#define VERSIONSTR "0.3 (April 21, 2009)" */
 /*#define VERSIONSTR "0.2   July 15, 2001"  */
+#endif
 
 
 /*
diff --git a/make-git-info b/make-git-info
new file mode 100755
index 0000000..31f9d38
--- /dev/null
+++ b/make-git-info
@@ -0,0 +1,21 @@
+#!/bin/sh
+
+desc=$(git describe --tags)
+
+if [ "$desc" = "" ]
+then
+    echo "#undef GIT_VERSION" > new-git-info.h
+else
+    auth=$(git log -n 1 "--pretty=format:%an <%ae> %aD")
+
+    echo "#define GIT_VERSION      "'"'"$desc"'"' >new-git-info.h
+    echo "#define GIT_AUTHOR_DATE  "'"'"$auth"'"' >>new-git-info.h
+fi
+
+# move-if-different
+if diff new-git-info.h git-info.h >/dev/null 2>&1
+then
+    rm new-git-info.h
+else
+    mv new-git-info.h git-info.h
+fi