driconf: Add proper dependency for compiling .mo files from .po files.

Previously this was happening unconditionally, leading to some excessive
rebuilding/relinking during builds.

Note that the .po files are not automatically updated due to changes to the
t_options.h file. Instead, translators should continue to use "make po"
manually. This is because after new strings are merged into the existing .po
file, manual work is still required by translators to ensure that the
translations are correct.

src/mesa/drivers/dri/common/xmlpool/.gitignore

@@ -5,3 +5,4 @@ nl
 sv
 options.h
 Makefile
+xmlpool.pot

src/mesa/drivers/dri/common/xmlpool/Makefile.am

@@ -61,36 +61,34 @@ clean:
 
 # Default target options.h
 options.h: LOCALEDIR := .
-options.h: t_options.h mo
+options.h: t_options.h $(MOS)
 	$(AM_V_GEN) $(PYTHON2) $(PYTHON_FLAGS) $(srcdir)/gen_xmlpool.py t_options.h $(LOCALEDIR) $(LANGS) > options.h
 
 # Update .mo files from the corresponding .po files.
-mo:
-	@for mo in $(MOS); do \
-		lang=$${mo%%/*}; \
-		echo "Updating $$mo from $$lang.po."; \
-		mkdir -p $${mo%/*}; \
-		msgfmt -o $$mo $$lang.po; \
-	done
+%/LC_MESSAGES/options.mo: %.po
+	@mo="$@" \
+	lang=$${mo%%/*}; \
+	echo "Updating ($$lang) $@ from $?."; \
+	mkdir -p $$lang/LC_MESSAGES; \
+	msgfmt -o $@ $?
 
 # Use this target to create or update .po files with new messages in
 # driconf.py.
-po: $(POS)
+po: $(POT)
+	@for po in $(POS); do \
+		if [ -f $$po ]; then \
+			echo "Merging new strings from $(POT) into $@."; \
+			mv $$po $$po~; \
+			msgmerge -o $$po $$po~ $(POT); \
+		else \
+			echo "Initializing $$po from $(POT)."; \
+			msginit -i $(POT) -o $$po~ --locale=$*; \
+			sed -e 's/charset=.*\\n/charset=UTF-8\\n/' $$po~ > $$po; \
+		fi \
+	done
 
 pot: $(POT)
 
 # Extract message catalog from driconf.py.
 $(POT): t_options.h
 	xgettext -L C --from-code utf-8 -o $(POT) t_options.h
-
-# Create or update a .po file for a specific language.
-%.po: $(POT)
-	@if [ -f $@ ]; then \
-		echo "Merging new strings from $(POT) into $@."; \
-		mv $@ $@~; \
-		msgmerge -o $@ $@~ $(POT); \
-	else \
-		echo "Initializing $@ from $(POT)."; \
-		msginit -i $(POT) -o $@~ --locale=$*; \
-		sed -e 's/charset=.*\\n/charset=UTF-8\\n/' $@~ > $@; \
-	fi