build system: Updating project Makefile should trigger a full rebuild

Project Makefile can set CFLAGS, macro defines, etc.

make/project.mk

@@ -90,7 +90,7 @@ export PROJECT_PATH
 endif
 
 # A list of the "common" makefiles, to use as a target dependency
-COMMON_MAKEFILES := $(abspath $(IDF_PATH)/make/project.mk $(IDF_PATH)/make/common.mk $(IDF_PATH)/make/component_wrapper.mk)
+COMMON_MAKEFILES := $(abspath $(IDF_PATH)/make/project.mk $(IDF_PATH)/make/common.mk $(IDF_PATH)/make/component_wrapper.mk $(firstword $(MAKEFILE_LIST)))
 export COMMON_MAKEFILES
 
 # The directory where we put all objects/libraries/binaries. The project Makefile can

tools/ci/test_build_system.sh

@@ -160,7 +160,7 @@ function run_tests()
     assert_rebuilt ${APP_BINS}
     assert_not_rebuilt ${BOOTLOADER_BINS}
 
-    print_status "sdkconfig update triggers recompiles"
+    print_status "sdkconfig update triggers full recompile"
     make
     take_build_snapshot
     touch sdkconfig
@@ -171,6 +171,16 @@ function run_tests()
     assert_rebuilt nvs_flash/src/nvs_api.o
     assert_rebuilt freertos/xtensa_vectors.o
 
+    print_status "Updating project Makefile triggers full recompile"
+    make
+    take_build_snapshot
+    touch Makefile
+    make
+    # similar to previous test
+    assert_rebuilt newlib/syscall_table.o
+    assert_rebuilt nvs_flash/src/nvs_api.o
+    assert_rebuilt freertos/xtensa_vectors.o
+
     print_status "All tests completed"
     if [ -n "${FAILURES}" ]; then
         echo "Some failures were detected:"