build: Forcefully re-create link to main Makefile

This commit makes sure that the symbolic link within the build directory
always points to the unikraft Makefile version that is used for a
build. This avoids issues when a project is build with multiple Unikraft
versions but using the same build path. The reason is that the build system
is invoking a sub-make call within the build directory using this symbolic
link.

Signed-off-by: Simon Kuenzer <simon@unikraft.io>
Reviewed-by: Cezar Craciunoiu <cezar.craciunoiu@unikraft.io>
Reviewed-by: Michalis Pappas <michalis@unikraft.io>
Reviewed-by: Maria Sfiraiala <maria.sfiraiala@gmail.com>
Approved-by: Razvan Deaconescu <razvand@unikraft.io>
GitHub-Closes: #1104

diff --git a/Makefile b/Makefile
index 44fa810adbf3d098a82541b7567031639c062dfa..ffad2708bd5255c3c84a9a944ba1431744f7f0a6 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1141,6 +1141,8 @@ export sub_make_exec:=1
 $(BUILD_DIR)/Makefile:
        $(call verbose_cmd,LN,$(notdir $@),$(HOSTLN) -sf $(CONFIG_UK_BASE)/Makefile $@)
 
+.PHONY: $(BUILD_DIR)/Makefile
+
 $(filter-out _all $(BUILD_DIR)/Makefile sub-make distclean properclean help $(lastword $(MAKEFILE_LIST)), \
   $(MAKECMDGOALS)) all: sub-make
        @: