[safe_mode] Conditionally compile callback when on_safe_mode is configured

esphome/components/safe_mode/__init__.py

@@ -59,9 +59,11 @@ async def to_code(config):
         var = cg.new_Pvariable(config[CONF_ID])
         await cg.register_component(var, config)
 
-        for conf in config.get(CONF_ON_SAFE_MODE, []):
-            trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-            await automation.build_automation(trigger, [], conf)
+        if on_safe_mode_config := config.get(CONF_ON_SAFE_MODE):
+            cg.add_define("USE_SAFE_MODE_CALLBACK")
+            for conf in on_safe_mode_config:
+                trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+                await automation.build_automation(trigger, [], conf)
 
         condition = var.should_enter_safe_mode(
             config[CONF_NUM_ATTEMPTS],

esphome/components/safe_mode/automation.h

@@ -1,4 +1,7 @@
 #pragma once
+#include "esphome/core/defines.h"
+
+#ifdef USE_SAFE_MODE_CALLBACK
 #include "safe_mode.h"
 
 #include "esphome/core/automation.h"
@@ -15,3 +18,5 @@ class SafeModeTrigger : public Trigger<> {
 
 }  // namespace safe_mode
 }  // namespace esphome
+
+#endif  // USE_SAFE_MODE_CALLBACK

esphome/components/safe_mode/safe_mode.cpp

@@ -126,7 +126,9 @@ bool SafeModeComponent::should_enter_safe_mode(uint8_t num_attempts, uint32_t en
 
   ESP_LOGW(TAG, "SAFE MODE IS ACTIVE");
 
+#ifdef USE_SAFE_MODE_CALLBACK
   this->safe_mode_callback_.call();
+#endif
 
   return true;
 }

esphome/components/safe_mode/safe_mode.h

@@ -25,9 +25,11 @@ class SafeModeComponent : public Component {
 
   void on_safe_shutdown() override;
 
+#ifdef USE_SAFE_MODE_CALLBACK
   void add_on_safe_mode_callback(std::function<void()> &&callback) {
     this->safe_mode_callback_.add(std::move(callback));
   }
+#endif
 
  protected:
   void write_rtc_(uint32_t val);
@@ -43,7 +45,9 @@ class SafeModeComponent : public Component {
   uint8_t safe_mode_num_attempts_{0};
   // Larger objects at the end
   ESPPreferenceObject rtc_;
+#ifdef USE_SAFE_MODE_CALLBACK
   CallbackManager<void()> safe_mode_callback_{};
+#endif
 
   static const uint32_t ENTER_SAFE_MODE_MAGIC =
       0x5afe5afe;  ///< a magic number to indicate that safe mode should be entered on next boot

esphome/core/defines.h

@@ -100,6 +100,7 @@
 #define USE_OUTPUT
 #define USE_POWER_SUPPLY
 #define USE_QR_CODE
+#define USE_SAFE_MODE_CALLBACK
 #define USE_SELECT
 #define USE_SENSOR
 #define USE_STATUS_LED