Makefile: Put VERSION info into version.texi rather than using -D

Unfortunately some older versions of makeinfo don't correctly
handle the -D command line option and fail to set the variable.
This then causes them to complain
 docs/qemu-ga-ref.texi:41: warning: undefined flag: VERSION

Work around this by doing as the autotools do, and writing
the information into a version.texi file which we then
include from the .texi files that need it.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487357968-31000-1-git-send-email-peter.maydell@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

.gitignore

@@ -107,6 +107,7 @@ docs/qemu-ga-ref.info*
 docs/qemu-qmp-ref.info*
 /qemu-ga-qapi.texi
 /qemu-qapi.texi
+/version.texi
 *.tps
 .stgit-*
 cscope.*

Makefile

@@ -516,7 +516,7 @@ distclean: clean
 	rm -f qemu-doc.vr qemu-doc.txt
 	rm -f config.log
 	rm -f linux-headers/asm
-	rm -f qemu-ga-qapi.texi qemu-qapi.texi
+	rm -f qemu-ga-qapi.texi qemu-qapi.texi version.texi
 	rm -f docs/qemu-qmp-ref.7 docs/qemu-ga-ref.7
 	rm -f docs/qemu-qmp-ref.txt docs/qemu-ga-ref.txt
 	rm -f docs/qemu-qmp-ref.pdf docs/qemu-ga-ref.pdf
@@ -663,21 +663,24 @@ ui/console-gl.o: $(SRC_PATH)/ui/console-gl.c \
 
 # documentation
 MAKEINFO=makeinfo
-MAKEINFOFLAGS=--no-split --number-sections -D 'VERSION $(VERSION)'
-TEXIFLAG=$(if $(V),,--quiet) --command='@set VERSION $(VERSION)'
+MAKEINFOFLAGS=--no-split --number-sections
+TEXIFLAG=$(if $(V),,--quiet)
 
-%.html: %.texi
+version.texi: $(SRC_PATH)/VERSION
+	$(call quiet-command,echo "@set VERSION $(VERSION)" > $@,"GEN","$@")
+
+%.html: %.texi version.texi
 	$(call quiet-command,LC_ALL=C $(MAKEINFO) $(MAKEINFOFLAGS) --no-headers \
 	--html $< -o $@,"GEN","$@")
 
-%.info: %.texi
+%.info: %.texi version.texi
 	$(call quiet-command,$(MAKEINFO) $(MAKEINFOFLAGS) $< -o $@,"GEN","$@")
 
-%.txt: %.texi
+%.txt: %.texi version.texi
 	$(call quiet-command,LC_ALL=C $(MAKEINFO) $(MAKEINFOFLAGS) --no-headers \
 	--plaintext $< -o $@,"GEN","$@")
 
-%.pdf: %.texi
+%.pdf: %.texi version.texi
 	$(call quiet-command,texi2pdf $(TEXIFLAG) -I $(SRC_PATH) -I . $< -o $@,"GEN","$@")
 
 qemu-options.texi: $(SRC_PATH)/qemu-options.hx $(SRC_PATH)/scripts/hxtool

docs/qemu-ga-ref.texi

@@ -1,6 +1,8 @@
 \input texinfo
 @setfilename qemu-ga-ref.info
 
+@include version.texi
+
 @exampleindent 0
 @paragraphindent 0
 

docs/qemu-qmp-ref.texi

@@ -1,6 +1,8 @@
 \input texinfo
 @setfilename qemu-qmp-ref.info
 
+@include version.texi
+
 @exampleindent 0
 @paragraphindent 0