[Qemu-devel] [PATCH v3 2/2] Makefile: Derive "PKGVERSION" from "git describe" by default

[Fam Zheng <famz@redhat.com>]

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>
---
 Makefile              | 22 +++++++++++++++++++++-
 linux-user/main.c     |  1 +
 qemu-img.c            |  1 +
 qmp.c                 |  1 +
 scripts/create_config |  4 ----
 vl.c                  |  1 +
 6 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/Makefile b/Makefile
index 1e2d6f9..5124f54 100644
--- a/Makefile
+++ b/Makefile
@@ -49,7 +49,7 @@ ifneq ($(filter-out $(UNCHECKED_GOALS),$(MAKECMDGOALS)),$(if $(MAKECMDGOALS),,fa
 endif
 endif
 
-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
@@ -166,6 +166,26 @@ 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 \
+			printf '" ('; \
+			if ! git status &>/dev/null; then \
+				printf "no-git"; \
+			else \
+				git describe 2>/dev/null | tr -d '\n'; \
+				if ! git diff-index --quiet HEAD &>/dev/null; then \
+					printf -- '-dirty'; \
+				fi \
+			fi; \
+			printf ')"\n'; \
+		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
diff --git a/linux-user/main.c b/linux-user/main.c
index b2bc6ab..8a11d02 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 4b56ad3..32e307c 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 3165f87..7df6543 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 b2d2ebb..d47057b 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 18d1423..97cad71 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"
 
-- 
2.8.2