Refactor CMakeLists.txt to improve path handling for MicroPython ESP32

Author: MATTYGILO

boards/MICROLITE_S3_SPIRAM_OCTAL/main/CMakeLists.txt

@@ -1,11 +1,24 @@
 # Include MicroPython ESP32 component.
 
-get_filename_component(CURRENT_DIR "." ABSOLUTE)
+get_filename_component(CURRENT_DIR "${CMAKE_CURRENT_LIST_DIR}" ABSOLUTE)
 message(STATUS "microlite/main/cmake: CURRENT_DIR=${CURRENT_DIR}")
 
-get_filename_component(MICROPY_DIR "../../../third_party/micropython" ABSOLUTE)
+# Compute MICROPY_DIR relative to this file to avoid brittle relative paths.
+get_filename_component(MICROPY_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../third_party/micropython" ABSOLUTE)
+get_filename_component(MICROPY_PORT_DIR "${CMAKE_CURRENT_LIST_DIR}/../../../third_party/micropython/ports/esp32" REALPATH)
 
-message (STATUS "microlite/main/cmake: MICROPY_DIR=${MICROPY_DIR}")
 
-set(PROJECT_DIR ${MICROPY_DIR}/ports/esp32)
-include(${PROJECT_DIR}/main_esp32s3/CMakeLists.txt)
+message(STATUS "microlite/main/cmake: MICROPY_DIR=${MICROPY_DIR}")
+
+message(STATUS "Including ${MICROPY_PORT_DIR}/main/CMakeLists.txt")
+include("${MICROPY_PORT_DIR}/main/CMakeLists.txt")
+
+## Prefer the S3-specific entry if present, otherwise fall back to the generic one.
+#if(EXISTS "${MICROPY_PORT_DIR}/main_esp32s3/CMakeLists.txt")
+#    message(STATUS "Including ${MICROPY_PORT_DIR}/main_esp32s3/CMakeLists.txt")
+#    include("${MICROPY_PORT_DIR}/main_esp32s3/CMakeLists.txt")
+#elseif(EXISTS "${MICROPY_PORT_DIR}/main/CMakeLists.txt")
+#
+#else()
+#    message(FATAL_ERROR "Could not find MicroPython ESP32 entry CMakeLists in ${MICROPY_PORT_DIR}. Expected one of:\n  ${MICROPY_PORT_DIR}/main_esp32s3/CMakeLists.txt\n  ${MICROPY_PORT_DIR}/main/CMakeLists.txt\nCheck that third_party/micropython/ports/esp32 exists and contains the correct CMake entry.")
+#endif()