add optional component dependencies after Kconfig options are known

Until this commit, Kconfig options (e.g. CONFIG_TINYUSB_ENABLED) were
used in conditions preceding idf_component_register to determine which
components need to be added to `arduino` component requirements.
However the Kconfig options aren't known at the early expansion stage,
when the component CMakeLists.txt files are expanded the first time
and requirements are evaluated. So all the conditions evaluated as if
the options were not set.
This commit changes the logic to only add these components as
dependencies when the Kconfig options are known. Dependencies become
"weak", which means that if one of the components isn't included into
the build for some reason, it is not added as a dependency.
This may happen, for example, if the component is not present in the
`components` directory or is excluded by setting `COMPONENTS` variable
in the project CMakeLists.txt file.
This also ensures that if the component is not present, it will not be
added as a dependency, and this will allow the build to proceed.

Follow-up to #5391.
Closes #5319.

Author: igrr

Diff for: CMakeLists.txt

@@ -163,26 +163,16 @@ set(priv_includes cores/esp32/libb64)
 set(requires spi_flash mbedtls mdns esp_adc_cal wifi_provisioning nghttp)
 set(priv_requires fatfs nvs_flash app_update spiffs bootloader_support openssl bt esp_ipc)
 
-if(IDF_TARGET MATCHES "esp32s2|esp32s3" AND CONFIG_TINYUSB_ENABLED)
-  list(APPEND priv_requires arduino_tinyusb)
-endif()
-if(NOT CONFIG_ARDUINO_SELECTIVE_COMPILATION OR CONFIG_ARDUINO_SELECTIVE_ArduinoOTA)
-  list(APPEND priv_requires esp_https_ota)
-endif()
-if(NOT CONFIG_ARDUINO_SELECTIVE_COMPILATION OR CONFIG_ARDUINO_SELECTIVE_LITTLEFS)
-  if(CONFIG_LITTLEFS_PAGE_SIZE)
-    list(APPEND priv_requires esp_littlefs)
-  endif()
-endif()
-
 idf_component_register(INCLUDE_DIRS ${includedirs} PRIV_INCLUDE_DIRS ${priv_includes} SRCS ${srcs} REQUIRES ${requires} PRIV_REQUIRES ${priv_requires})
 
-if(IDF_TARGET STREQUAL "esp32")
-target_compile_options(${COMPONENT_TARGET} PUBLIC -DARDUINO=10812 -DARDUINO_ESP32_DEV -DARDUINO_ARCH_ESP32 -DARDUINO_BOARD="ESP32_DEV" -DARDUINO_VARIANT="esp32" -DESP32)
-endif()
-if(IDF_TARGET STREQUAL "esp32s2")
-target_compile_options(${COMPONENT_TARGET} PUBLIC -DARDUINO=10812 -DARDUINO_ESP32S2_DEV -DARDUINO_ARCH_ESP32 -DARDUINO_BOARD="ESP32S2_DEV" -DARDUINO_VARIANT="esp32s2" -DESP32)
-endif()
+string(TOUPPER ${CONFIG_IDF_TARGET} idf_target_caps)
+target_compile_options(${COMPONENT_TARGET} PUBLIC
+    -DARDUINO=10812
+    -DARDUINO_${idf_target_caps}_DEV
+    -DARDUINO_ARCH_ESP32
+    -DARDUINO_BOARD="${idf_target_caps}_DEV"
+    -DARDUINO_VARIANT="${CONFIG_IDF_TARGET}"
+    -DESP32)
 
 if(CONFIG_AUTOSTART_ARDUINO)
     # in autostart mode, arduino-esp32 contains app_main() function and needs to
@@ -195,3 +185,22 @@ if(CONFIG_AUTOSTART_ARDUINO)
     # (As they are C++ symbol, we need to add the C++ mangled names.)
     target_link_libraries(${COMPONENT_LIB} INTERFACE "-u _Z5setupv -u _Z4loopv")
 endif()
+
+# This function adds a dependency on the given component if the component is included into the build.
+function(maybe_add_component component_name)
+    idf_build_get_property(components BUILD_COMPONENTS)
+    if (${component_name} IN_LIST components)
+        idf_component_get_property(lib_name ${component_name} COMPONENT_LIB)
+        target_link_libraries(${COMPONENT_LIB} PUBLIC ${lib_name})
+    endif()
+endfunction()
+
+if(IDF_TARGET MATCHES "esp32s2|esp32s3" AND CONFIG_TINYUSB_ENABLED)
+    maybe_add_component(arduino_tinyusb)
+endif()
+if(NOT CONFIG_ARDUINO_SELECTIVE_COMPILATION OR CONFIG_ARDUINO_SELECTIVE_ArduinoOTA)
+    maybe_add_component(esp_https_ota)
+endif()
+if(NOT CONFIG_ARDUINO_SELECTIVE_COMPILATION OR CONFIG_ARDUINO_SELECTIVE_LITTLEFS)
+    maybe_add_component(esp_littlefs)
+endif()