Patch #1826459: Make: reconfigure on configure change (saving environment)

svn-id: r29435

Makefile

@@ -16,7 +16,7 @@ MODULES     :=
 MODULE_DIRS :=
 
 # Load the make rules generated by configure
-include config.mk
+-include config.mk
 
 CXXFLAGS:= -Wall $(CXXFLAGS)
 CXXFLAGS+= -Wno-long-long -Wno-multichar -Wno-unknown-pragmas
@@ -44,9 +44,14 @@ include $(srcdir)/Makefile.common
 
 # check if configure has been run or has been changed since last run
 config.mk: $(srcdir)/configure
-	@echo "You need to run ./configure before you can run make"
-	@echo "Either you haven't run it before or it has changed."
-	@exit 1
+ifdef CONFIG_MK_IS_PRESENT
+	@echo "Running $(srcdir)/configure with the last specified parameters"
+	@sleep 2s
+	@LDFLAGS=$(SAVED_LDFLAGS) CXX=$(SAVED_CXX) CXXFLAGS=$(SAVED_CXXFLAGS) CPPFLAGS=$(SAVED_CPPFLAGS) \
+		$(srcdir)/configure $(SAVED_CONFIGFLAGS)
+else
+	$(error You need to run $(srcdir)/configure before you can run make. Check $(srcdir)/configure --help for a list of parameters)
+endif
 
 install: all
 	$(INSTALL) -d "$(DESTDIR)$(BINDIR)"

configure

@@ -9,6 +9,12 @@
 # * detect whether the chosen backend is available (e.g. call sdl-config)
 # * ....
 
+# Save the current environment variables for next runs
+SAVED_CONFIGFLAGS=$@
+SAVED_LDFLAGS=$LDFLAGS
+SAVED_CXX=$CXX
+SAVED_CXXFLAGS=$CXXFLAGS
+SAVED_CPPFLAGS=$CPPFLAGS
 
 # use environment vars if set
 CXXFLAGS="$CXXFLAGS $CPPFLAGS"
@@ -1625,6 +1631,14 @@ INCLUDES += $INCLUDES
 OBJS += $OBJS
 DEFINES += $DEFINES
 LDFLAGS += $LDFLAGS
+
+SAVED_CONFIGFLAGS := $SAVED_CONFIGFLAGS
+SAVED_LDFLAGS     := $SAVED_LDFLAGS
+SAVED_CXX         := $SAVED_CXX
+SAVED_CXXFLAGS    := $SAVED_CXXFLAGS
+SAVED_CPPFLAGS    := $SAVED_CPPFLAGS
+
+CONFIG_MK_IS_PRESENT := 1
 EOF
 
 #