Make "make clean" in compiler/ only clean the stage we want to clean

If you "make clean" in the root then we still clean all stages

compiler/Makefile

@@ -56,12 +56,6 @@ stage3 ::
 	$(MAKE) stage=3
 
 clean distclean::
-	-$(CABAL) clean --distpref dist-stage1
-	-$(CABAL) clean --distpref dist-stage2
-	-$(CABAL) clean --distpref dist-stage3
-	$(RM) -f Makefile-stage1
-	$(RM) -f Makefile-stage2
-	$(RM) -f Makefile-stage3
 	$(RM) -f prelude/primops.txt
 	$(RM) -f $(PRIMOP_BITS)
 	$(RM) -f $(CONFIG_HS)
@@ -69,6 +63,16 @@ clean distclean::
 	$(RM) -rf stage1 stage2plus
 	$(RM) -f $(STAGE3_PACKAGE_CONF)
 
+ifeq "$(CLEAN_ALL_STAGES)" "YES"
+clean distclean:: clean.stage.1 clean.stage.2 clean.stage.3
+else
+clean distclean:: clean.stage.$(stage)
+endif
+
+clean.stage.%:
+	-$(CABAL) clean --distpref dist-stage$*
+	$(RM) -f Makefile-stage$*
+
 CONFIGURE_FLAGS_STAGE1 += --flags=stage1
 CONFIGURE_FLAGS_STAGE2 += --flags=-stage1
 

mk/recurse.mk

@@ -76,7 +76,7 @@ $(ALL_TARGET) docs runtests $(BOOT_TARGET) TAGS clean distclean mostlyclean main
 	  echo "== $(MAKE) $@ $(MFLAGS);"; \
 	  echo " in $(shell pwd)/$$i"; \
 	  echo "------------------------------------------------------------------------"; \
-	  $(MAKE) --no-print-directory -C $$i $(MFLAGS) $@; \
+	  $(MAKE) --no-print-directory -C $$i $(MFLAGS) $@ CLEAN_ALL_STAGES=YES; \
 	  if [ $$? -eq 0 -o $$x_on_err -eq 0 ]; \
 	      then echo "Finished making $@ in $$i": $$?; \
 	      else echo "Failed making $@ in $$i": $$?; exit 1; \