[time] Skip automation.cpp when no on_time or on_time_sync automation is configured (#18750)

esphome/components/time/__init__.py

@@ -426,7 +426,12 @@ async def setup_time_core_(time_var, config):
             raise EsphomeError(f"Invalid timezone: {timezone}") from e
         _emit_parsed_timezone_fields(parsed)
 
-    for conf in config.get(CONF_ON_TIME, []):
+    on_time = config.get(CONF_ON_TIME, [])
+    on_time_sync = config.get(CONF_ON_TIME_SYNC, [])
+    if on_time or on_time_sync:
+        cg.add_define("USE_TIME_TRIGGERS")
+
+    for conf in on_time:
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], time_var)
 
         seconds = conf.get(CONF_SECONDS, list(range(61)))
@@ -445,7 +450,7 @@ async def setup_time_core_(time_var, config):
         await cg.register_component(trigger, conf)
         await automation.build_automation(trigger, [], conf)
 
-    for conf in config.get(CONF_ON_TIME_SYNC, []):
+    for conf in on_time_sync:
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], time_var)
 
         await cg.register_component(trigger, conf)
@@ -479,7 +484,11 @@ async def time_has_time_to_code(config, condition_id, template_arg, args):
 
 
 # posix_tz.cpp is fully #ifdef'd on USE_TIME_TIMEZONE, set only when a
-# timezone is configured or detected.
+# timezone is configured or detected; automation.cpp holds the on_time and
+# on_time_sync triggers and is #ifdef'd on USE_TIME_TRIGGERS.
 FILTER_SOURCE_FILES = filter_source_files_from_defines(
-    {"posix_tz.cpp": "USE_TIME_TIMEZONE"}
+    {
+        "posix_tz.cpp": "USE_TIME_TIMEZONE",
+        "automation.cpp": "USE_TIME_TRIGGERS",
+    }
 )

esphome/components/time/automation.cpp

@@ -1,4 +1,5 @@
 #include "automation.h"
+#ifdef USE_TIME_TRIGGERS
 
 #include "esphome/core/log.h"
 
@@ -98,3 +99,5 @@ SyncTrigger::SyncTrigger(RealTimeClock *rtc) : rtc_(rtc) {
 }
 
 }  // namespace esphome::time
+
+#endif  // USE_TIME_TRIGGERS

esphome/components/time/automation.h

@@ -1,5 +1,8 @@
 #pragma once
 
+#include "esphome/core/defines.h"
+#ifdef USE_TIME_TRIGGERS
+
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/time.h"
@@ -49,3 +52,5 @@ class SyncTrigger final : public Trigger<>, public Component {
   RealTimeClock *rtc_;
 };
 }  // namespace esphome::time
+
+#endif  // USE_TIME_TRIGGERS

esphome/core/defines.h

@@ -188,6 +188,7 @@
 #define USE_TEXT_SENSOR
 #define USE_TEXT_SENSOR_FILTER
 #define USE_TIME
+#define USE_TIME_TRIGGERS
 #define USE_TOUCHSCREEN
 #define USE_UART_DEBUGGER
 #define USE_UART_WAKE_LOOP_ON_RX

tests/component_tests/time/config/no_triggers.yaml

@@ -0,0 +1,15 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+wifi:
+  ssid: "test_ssid"
+  password: "test_password"
+
+time:
+  - platform: sntp
+    id: sntp_time

tests/component_tests/time/config/on_time.yaml

@@ -0,0 +1,21 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+wifi:
+  ssid: "test_ssid"
+  password: "test_password"
+
+logger:
+
+time:
+  - platform: sntp
+    id: sntp_time
+    on_time:
+      - seconds: 0
+        then:
+          - logger.log: tick

tests/component_tests/time/config/on_time_sync.yaml

@@ -0,0 +1,20 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  framework:
+    type: esp-idf
+
+wifi:
+  ssid: "test_ssid"
+  password: "test_password"
+
+logger:
+
+time:
+  - platform: sntp
+    id: sntp_time
+    on_time_sync:
+      then:
+        - logger.log: synced

tests/component_tests/time/test_triggers.py

@@ -0,0 +1,28 @@
+"""automation.cpp (CronTrigger and SyncTrigger) is only compiled when an
+on_time or on_time_sync automation exists, so the define must follow them."""
+
+from collections.abc import Callable
+from pathlib import Path
+
+import pytest
+
+from esphome.core import CORE
+
+
+@pytest.mark.parametrize(
+    ("fixture", "emits"),
+    [
+        ("no_triggers.yaml", False),
+        ("on_time.yaml", True),
+        ("on_time_sync.yaml", True),
+    ],
+)
+def test_triggers_define_follows_automations(
+    fixture: str,
+    emits: bool,
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    generate_main(component_config_path(fixture))
+    defines = {define.name for define in CORE.defines}
+    assert ("USE_TIME_TRIGGERS" in defines) is emits