Makefile: Derive "PKGVERSION" from "git describe" by default

Currently, if not specified in "./configure", QEMU_PKGVERSION will be
empty. Write a rule in Makefile to generate a value from "git describe"
combined with a possible git tree cleanness suffix, and write into a new
header.

    $ cat qemu-version.h
    #define QEMU_PKGVERSION "-v2.6.0-557-gd6550e9-dirty"

Include the header in .c files where the macro is referenced. It's not
necessary to include it in all files, otherwise each time the content of
the file changes, all sources have to be recompiled.

Signed-off-by: Fam Zheng <famz@redhat.com>
Message-Id: <1464774261-648-3-git-send-email-famz@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

6 files changed, 25 insertions, 5 deletions

diff --git a/Makefile b/Makefile
index 38751928c4..ed4032a373 100644
--- a/Makefile
+++ b/Makefile
@@ -50,7 +50,7 @@ endif
 
 include $(SRC_PATH)/rules.mak
 
-GENERATED_HEADERS = config-host.h qemu-options.def
+GENERATED_HEADERS = qemu-version.h config-host.h qemu-options.def
 GENERATED_HEADERS += qmp-commands.h qapi-types.h qapi-visit.h qapi-event.h
 GENERATED_SOURCES += qmp-marshal.c qapi-types.c qapi-visit.c qapi-event.c
 GENERATED_HEADERS += qmp-introspect.h
@@ -167,6 +167,26 @@ endif
 
 all: $(DOCS) $(TOOLS) $(HELPERS-y) recurse-all modules
 
+qemu-version.h: FORCE
+	$(call quiet-command, \
+		(cd $(SRC_PATH); \
+		printf '#define QEMU_PKGVERSION '; \
+		if test -n "$(PKGVERSION)"; then \
+			printf '"$(PKGVERSION)"\n'; \
+		else \
+			if test -d .git; then \
+				printf '" ('; \
+				git describe --match 'v*' 2>/dev/null | tr -d '\n'; \
+				if ! git diff-index --quiet HEAD &>/dev/null; then \
+					printf -- '-dirty'; \
+				fi; \
+				printf ')"\n'; \
+			else \
+				printf '""\n'; \
+			fi; \
+		fi) > $@.tmp)
+	$(call quiet-command, cmp --quiet $@ $@.tmp || mv $@.tmp $@)
+
 config-host.h: config-host.h-timestamp
 config-host.h-timestamp: config-host.mak
 qemu-options.def: $(SRC_PATH)/qemu-options.hx $(SRC_PATH)/scripts/hxtool
diff --git a/linux-user/main.c b/linux-user/main.c
index b2bc6ab2f7..8a11d0219e 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -17,6 +17,7 @@
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 #include "qemu/osdep.h"
+#include "qemu-version.h"
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <sys/resource.h>
diff --git a/qemu-img.c b/qemu-img.c
index 4b56ad36aa..32e307c075 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qemu-version.h"
 #include "qapi/error.h"
 #include "qapi-visit.h"
 #include "qapi/qmp-output-visitor.h"
diff --git a/qmp.c b/qmp.c
index 3165f8726b..7df6543871 100644
--- a/qmp.c
+++ b/qmp.c
@@ -14,6 +14,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "qemu-version.h"
 #include "qemu/cutils.h"
 #include "monitor/monitor.h"
 #include "sysemu/sysemu.h"
diff --git a/scripts/create_config b/scripts/create_config
index b2d2ebb452..d47057b9d0 100755
--- a/scripts/create_config
+++ b/scripts/create_config
@@ -9,10 +9,6 @@ case $line in
     version=${line#*=}
     echo "#define QEMU_VERSION \"$version\""
     ;;
- PKGVERSION=*) # configuration
-    pkgversion=${line#*=}
-    echo "#define QEMU_PKGVERSION \"$pkgversion\""
-    ;;
  qemu_*dir=*) # qemu-specific directory configuration
     name=${line%=*}
     value=${line#*=}
diff --git a/vl.c b/vl.c
index 2f74fe8fb6..9539f92694 100644
--- a/vl.c
+++ b/vl.c
@@ -22,6 +22,7 @@
  * THE SOFTWARE.
  */
 #include "qemu/osdep.h"
+#include "qemu-version.h"
 #include "qemu/cutils.h"
 #include "qemu/help_option.h"