[core] add support for custom platform (#7616)

Co-authored-by: Tomasz Duda <tomaszduda23@gmai.com>

esphome/components/bk72xx/__init__.py

@@ -19,6 +19,7 @@ from .boards import BK72XX_BOARD_PINS, BK72XX_BOARDS
 
 CODEOWNERS = ["@kuba2k2"]
 AUTO_LOAD = ["libretiny"]
+IS_TARGET_PLATFORM = True
 
 COMPONENT_DATA = LibreTinyComponent(
     name=COMPONENT_BK72XX,

esphome/components/esp32/__init__.py

@@ -64,6 +64,7 @@ from .gpio import esp32_pin_to_code  # noqa
 _LOGGER = logging.getLogger(__name__)
 CODEOWNERS = ["@esphome/core"]
 AUTO_LOAD = ["preferences"]
+IS_TARGET_PLATFORM = True
 
 CONF_RELEASE = "release"
 

esphome/components/esp8266/__init__.py

@@ -34,6 +34,7 @@ from .gpio import PinInitialState, add_pin_initial_states_array
 CODEOWNERS = ["@esphome/core"]
 _LOGGER = logging.getLogger(__name__)
 AUTO_LOAD = ["preferences"]
+IS_TARGET_PLATFORM = True
 
 
 def set_core_data(config):

esphome/components/host/__init__.py

@@ -17,6 +17,7 @@ from .gpio import host_pin_to_code  # noqa
 
 CODEOWNERS = ["@esphome/core", "@clydebarrow"]
 AUTO_LOAD = ["network", "preferences"]
+IS_TARGET_PLATFORM = True
 
 
 def set_core_data(config):

esphome/components/libretiny/__init__.py

@@ -47,6 +47,7 @@ from .const import (
 _LOGGER = logging.getLogger(__name__)
 CODEOWNERS = ["@kuba2k2"]
 AUTO_LOAD = ["preferences"]
+IS_TARGET_PLATFORM = True
 
 
 def _detect_variant(value):

esphome/components/rp2040/__init__.py

@@ -27,6 +27,7 @@ from .gpio import rp2040_pin_to_code  # noqa
 _LOGGER = logging.getLogger(__name__)
 CODEOWNERS = ["@jesserockz"]
 AUTO_LOAD = ["preferences"]
+IS_TARGET_PLATFORM = True
 
 
 def set_core_data(config):

esphome/components/rtl87xx/__init__.py

@@ -19,6 +19,8 @@ from .boards import RTL87XX_BOARD_PINS, RTL87XX_BOARDS
 
 CODEOWNERS = ["@kuba2k2"]
 AUTO_LOAD = ["libretiny"]
+IS_TARGET_PLATFORM = True
+
 
 COMPONENT_DATA = LibreTinyComponent(
     name=COMPONENT_RTL87XX,

esphome/config.py

@@ -22,7 +22,6 @@ from esphome.const import (
     CONF_PACKAGES,
     CONF_PLATFORM,
     CONF_SUBSTITUTIONS,
-    TARGET_PLATFORMS,
 )
 from esphome.core import CORE, DocumentRange, EsphomeError
 import esphome.core.config as core_config
@@ -833,7 +832,7 @@ def validate_config(
     result[CONF_ESPHOME] = config[CONF_ESPHOME]
     result.add_output_path([CONF_ESPHOME], CONF_ESPHOME)
     try:
-        core_config.preload_core_config(config, result)
+        target_platform = core_config.preload_core_config(config, result)
     except vol.Invalid as err:
         result.add_error(err)
         return result
@@ -845,9 +844,9 @@ def validate_config(
         cv.All(cv.version_number, cv.validate_esphome_version)(min_version)
 
     # First run platform validation steps
-    for key in TARGET_PLATFORMS:
-        if key in config:
-            result.add_validation_step(LoadValidationStep(key, config[key]))
+    result.add_validation_step(
+        LoadValidationStep(target_platform, config[target_platform])
+    )
     result.run_validation_steps()
 
     if result.errors:

esphome/const.py

@@ -15,15 +15,6 @@ PLATFORM_LIBRETINY_OLDSTYLE = "libretiny"
 PLATFORM_RP2040 = "rp2040"
 PLATFORM_RTL87XX = "rtl87xx"
 
-TARGET_PLATFORMS = [
-    PLATFORM_BK72XX,
-    PLATFORM_ESP32,
-    PLATFORM_ESP8266,
-    PLATFORM_HOST,
-    PLATFORM_LIBRETINY_OLDSTYLE,
-    PLATFORM_RP2040,
-    PLATFORM_RTL87XX,
-]
 
 SOURCE_FILE_EXTENSIONS = {".cpp", ".hpp", ".h", ".c", ".tcc", ".ino"}
 HEADER_FILE_EXTENSIONS = {".h", ".hpp", ".tcc"}

esphome/core/config.py

@@ -1,6 +1,7 @@
 import logging
 import multiprocessing
 import os
+from pathlib import Path
 
 from esphome import automation
 import esphome.codegen as cg
@@ -28,7 +29,6 @@ from esphome.const import (
     CONF_TRIGGER_ID,
     CONF_VERSION,
     KEY_CORE,
-    TARGET_PLATFORMS,
     __version__ as ESPHOME_VERSION,
 )
 from esphome.core import CORE, coroutine_with_priority
@@ -174,7 +174,31 @@ PRELOAD_CONFIG_SCHEMA = cv.Schema(
 )
 
 
-def preload_core_config(config, result):
+def _is_target_platform(name):
+    from esphome.loader import get_component
+
+    try:
+        if get_component(name, True).is_target_platform:
+            return True
+    except KeyError:
+        pass
+    return False
+
+
+def _list_target_platforms():
+    target_platforms = []
+    root = Path(__file__).parents[1]
+    for path in (root / "components").iterdir():
+        if not path.is_dir():
+            continue
+        if not (path / "__init__.py").is_file():
+            continue
+        if _is_target_platform(path.name):
+            target_platforms += [path.name]
+    return target_platforms
+
+
+def preload_core_config(config, result) -> str:
     with cv.prepend_path(CONF_ESPHOME):
         conf = PRELOAD_CONFIG_SCHEMA(config[CONF_ESPHOME])
 
@@ -187,12 +211,16 @@ def preload_core_config(config, result):
         conf[CONF_BUILD_PATH] = os.path.join(build_path, CORE.name)
     CORE.build_path = CORE.relative_internal_path(conf[CONF_BUILD_PATH])
 
-    target_platforms = [key for key in TARGET_PLATFORMS if key in config]
+    target_platforms = []
+
+    for domain, _ in config.items():
+        if _is_target_platform(domain):
+            target_platforms += [domain]
 
     if not target_platforms:
         raise cv.Invalid(
             "Platform missing. You must include one of the available platform keys: "
-            + ", ".join(TARGET_PLATFORMS),
+            + ", ".join(_list_target_platforms()),
             [CONF_ESPHOME],
         )
     if len(target_platforms) > 1:
@@ -202,6 +230,7 @@ def preload_core_config(config, result):
         )
 
     config[CONF_ESPHOME] = conf
+    return target_platforms[0]
 
 
 def include_file(path, basename):

esphome/loader.py

@@ -52,6 +52,10 @@ class ComponentManifest:
     def is_platform_component(self) -> bool:
         return getattr(self.module, "IS_PLATFORM_COMPONENT", False)
 
+    @property
+    def is_target_platform(self) -> bool:
+        return getattr(self.module, "IS_TARGET_PLATFORM", False)
+
     @property
     def config_schema(self) -> Optional[Any]:
         return getattr(self.module, "CONFIG_SCHEMA", None)
@@ -169,13 +173,15 @@ def install_custom_components_meta_finder():
     install_meta_finder(custom_components_dir)
 
 
-def _lookup_module(domain):
+def _lookup_module(domain, exception):
     if domain in _COMPONENT_CACHE:
         return _COMPONENT_CACHE[domain]
 
     try:
         module = importlib.import_module(f"esphome.components.{domain}")
     except ImportError as e:
+        if exception:
+            raise
         if "No module named" in str(e):
             _LOGGER.info(
                 "Unable to import component %s: %s", domain, str(e), exc_info=False
@@ -184,6 +190,8 @@ def _lookup_module(domain):
             _LOGGER.error("Unable to import component %s:", domain, exc_info=True)
         return None
     except Exception:  # pylint: disable=broad-except
+        if exception:
+            raise
         _LOGGER.error("Unable to load component %s:", domain, exc_info=True)
         return None
 
@@ -192,14 +200,14 @@ def _lookup_module(domain):
     return manif
 
 
-def get_component(domain):
+def get_component(domain, exception=False):
     assert "." not in domain
-    return _lookup_module(domain)
+    return _lookup_module(domain, exception)
 
 
 def get_platform(domain, platform):
     full = f"{platform}.{domain}"
-    return _lookup_module(full)
+    return _lookup_module(full, False)
 
 
 _COMPONENT_CACHE = {}