move git_version_string into version.c

The global git_version_string currently lives in git.c, but
doesn't have anything to do with the git wrapper. Let's move
it into its own file, where it will be more appropriate to
build more version-related functions.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Makefile

@@ -799,6 +799,7 @@ LIB_OBJS += usage.o
 LIB_OBJS += userdiff.o
 LIB_OBJS += utf8.o
 LIB_OBJS += varint.o
+LIB_OBJS += version.o
 LIB_OBJS += walker.o
 LIB_OBJS += wrapper.o
 LIB_OBJS += write_or_die.o
@@ -1962,7 +1963,7 @@ strip: $(PROGRAMS) git$X
 	$(STRIP) $(STRIP_OPTS) $(PROGRAMS) git$X
 
 git.o: common-cmds.h
-git.sp git.s git.o: EXTRA_CPPFLAGS = -DGIT_VERSION='"$(GIT_VERSION)"' \
+git.sp git.s git.o: EXTRA_CPPFLAGS = \
 	'-DGIT_HTML_PATH="$(htmldir_SQ)"' \
 	'-DGIT_MAN_PATH="$(mandir_SQ)"' \
 	'-DGIT_INFO_PATH="$(infodir_SQ)"'
@@ -1979,6 +1980,9 @@ builtin/help.sp builtin/help.s builtin/help.o: EXTRA_CPPFLAGS = \
 	'-DGIT_MAN_PATH="$(mandir_SQ)"' \
 	'-DGIT_INFO_PATH="$(infodir_SQ)"'
 
+version.sp version.s version.o: EXTRA_CPPFLAGS = \
+	'-DGIT_VERSION="$(GIT_VERSION)"'
+
 $(BUILT_INS): git$X
 	$(QUIET_BUILT_IN)$(RM) $@ && \
 	ln git$X $@ 2>/dev/null || \
@@ -2089,7 +2093,7 @@ configure: configure.ac
 	$(RM) $<+
 
 # These can record GIT_VERSION
-git.o git.spec http.o \
+version.o git.spec http.o \
 	$(patsubst %.sh,%,$(SCRIPT_SH)) \
 	$(patsubst %.perl,%,$(SCRIPT_PERL)) \
 	: GIT-VERSION-FILE

builtin.h

@@ -9,7 +9,6 @@
 
 #define DEFAULT_MERGE_LOG_LEN 20
 
-extern const char git_version_string[];
 extern const char git_usage_string[];
 extern const char git_more_info_string[];
 

builtin/log.c

@@ -21,6 +21,7 @@
 #include "parse-options.h"
 #include "branch.h"
 #include "streaming.h"
+#include "version.h"
 
 /* Set a default date-time format for git log ("log.date" config variable) */
 static const char *default_date_mode = NULL;

git.c

@@ -256,8 +256,6 @@ static int handle_alias(int *argcp, const char ***argv)
 	return ret;
 }
 
-const char git_version_string[] = GIT_VERSION;
-
 #define RUN_SETUP		(1<<0)
 #define RUN_SETUP_GENTLY	(1<<1)
 #define USE_PAGER		(1<<2)

help.c

@@ -6,6 +6,7 @@
 #include "common-cmds.h"
 #include "string-list.h"
 #include "column.h"
+#include "version.h"
 
 void add_cmdname(struct cmdnames *cmds, const char *name, int len)
 {

version.c

@@ -0,0 +1,4 @@
+#include "git-compat-util.h"
+#include "version.h"
+
+const char git_version_string[] = GIT_VERSION;

version.h

@@ -0,0 +1,6 @@
+#ifndef VERSION_H
+#define VERSION_H
+
+extern const char git_version_string[];
+
+#endif /* VERSION_H */