MBED_APP_JSON_PATH should no longer be required, as some projects don't need it

.github/workflows/greentea_cmake.yml

@@ -18,7 +18,7 @@ jobs:
       - name: Build NUCLEO_G031K8 with baremetal profile
         run: |
             rm -rf __build
-            cmake -S . -B __build -GNinja -DCMAKE_CTEST_ARGUMENTS="--output-on-failure;-V" -DMBED_BUILD_GREENTEA_TESTS=ON -DMBED_GREENTEA_TEST_BAREMETAL=ON -DMBED_GREENTEA_SERIAL_PORT=/dev/ttyDUMMY -DMBED_TARGET=NUCLEO_G031K8 -DMBED_APP_JSON=TESTS/configs/baremetal.json
+            cmake -S . -B __build -GNinja -DCMAKE_CTEST_ARGUMENTS="--output-on-failure;-V" -DMBED_BUILD_GREENTEA_TESTS=ON -DMBED_GREENTEA_TEST_BAREMETAL=ON -DMBED_GREENTEA_SERIAL_PORT=/dev/ttyDUMMY -DMBED_TARGET=NUCLEO_G031K8 -DMBED_APP_JSON_PATH=TESTS/configs/baremetal.json
             cmake --build __build
 
       - name: Build ARM_MUSCA_S1 with full profile

tools/cmake/mbed_generate_configuration.cmake

@@ -35,11 +35,12 @@ get_filename_component(CUSTOM_TARGETS_JSON_PATH "${CUSTOM_TARGETS_JSON_PATH}" AB
 # Check if mbed_app.json was modified
 # Note: if the path is an empty string, get_filename_component(ABSOLUTE) will convert it to a directory,
 # so we have to verify that the path we have is a file, not a dir.
-if(NOT EXISTS "${MBED_APP_JSON_PATH}" OR IS_DIRECTORY "${MBED_APP_JSON_PATH}")
-    message(FATAL_ERROR "Failed to find mbed_app.json at ${MBED_APP_JSON_PATH}")
+if(EXISTS "${MBED_APP_JSON_PATH}" AND (NOT IS_DIRECTORY "${MBED_APP_JSON_PATH}"))
+    file(TIMESTAMP "${MBED_APP_JSON_PATH}" MBED_APP_JSON_TIMESTAMP "%s" UTC)
+else()
+    set(MBED_APP_JSON_TIMESTAMP "<none>")
 endif()
 
-file(TIMESTAMP "${MBED_APP_JSON_PATH}" MBED_APP_JSON_TIMESTAMP "%s" UTC)
 if(NOT MBED_NEED_TO_RECONFIGURE)
     if(NOT "${MBED_INTERNAL_LAST_MBED_APP_JSON_TIMESTAMP}" STREQUAL "${MBED_APP_JSON_TIMESTAMP}")
         message(STATUS "Mbed: mbed_app.json modified, regenerating configs...")
@@ -76,6 +77,12 @@ endif()
 
 if(MBED_NEED_TO_RECONFIGURE)
     # Generate mbed_config.cmake for this target
+    if(EXISTS "${MBED_APP_JSON_PATH}" AND (NOT IS_DIRECTORY "${MBED_APP_JSON_PATH}"))
+        set(APP_CONFIG_ARGUMENT --app-config "${MBED_APP_JSON_PATH}")
+    else()
+        set(APP_CONFIG_ARGUMENT "")
+    endif()
+
     if(EXISTS "${CUSTOM_TARGETS_JSON_PATH}" AND (NOT IS_DIRECTORY "${CUSTOM_TARGETS_JSON_PATH}"))
         set(CUSTOM_TARGET_ARGUMENT --custom-targets-json "${CUSTOM_TARGETS_JSON_PATH}")
     else()
@@ -92,7 +99,7 @@ if(MBED_NEED_TO_RECONFIGURE)
         -m "${MBED_TARGET}"
         --mbed-os-path ${CMAKE_CURRENT_LIST_DIR}/../..
         --output-dir ${CMAKE_CURRENT_BINARY_DIR}
-        --app-config "${MBED_APP_JSON_PATH}"
+        ${APP_CONFIG_ARGUMENT}
         ${CUSTOM_TARGET_ARGUMENT})
 
     execute_process(

tools/cmake/tests/mbed_test_mode/CMakeLists.txt

@@ -4,7 +4,6 @@
 cmake_minimum_required(VERSION 3.19.0 FATAL_ERROR)
 
 set(MBED_PATH ${CMAKE_CURRENT_SOURCE_DIR}/../../../.. CACHE INTERNAL "")
-set(MBED_CONFIG_PATH ${CMAKE_CURRENT_BINARY_DIR} CACHE STATIC "")
 
 include(${MBED_PATH}/tools/cmake/app.cmake)
 

tools/cmake/tests/multiple_executables/CMakeLists.txt

@@ -4,7 +4,6 @@
 cmake_minimum_required(VERSION 3.19.0)
 
 set(MBED_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../../../..")
-set(MBED_CONFIG_PATH "${CMAKE_CURRENT_BINARY_DIR}")
 
 include("${MBED_PATH}/tools/cmake/app.cmake")