From 1b6471f4b0ff273e15130bf5e77e1c31e577efdb Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Fri, 7 Nov 2025 16:30:38 -0600
Subject: [PATCH] cleanups

---
 esphome/components/api/__init__.py        | 3 +++
 esphome/components/web_server/__init__.py | 3 +++
 esphome/core/__init__.py                  | 5 +++++
 esphome/core/config.py                    | 9 +++++++++
 esphome/core/controller_registry.cpp      | 7 ++++++-
 esphome/core/controller_registry.h        | 9 +++++++--
 esphome/core/defines.h                    | 2 ++
 7 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/esphome/components/api/__init__.py b/esphome/components/api/__init__.py
index 449572c0e5..023e4bf115 100644
--- a/esphome/components/api/__init__.py
+++ b/esphome/components/api/__init__.py
@@ -244,6 +244,9 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID])
     await cg.register_component(var, config)
 
+    # Track controller registration for StaticVector sizing
+    CORE.register_controller()
+
     cg.add(var.set_port(config[CONF_PORT]))
     if config[CONF_PASSWORD]:
         cg.add_define("USE_API_PASSWORD")
diff --git a/esphome/components/web_server/__init__.py b/esphome/components/web_server/__init__.py
index a7fdf30eef..17ad496f30 100644
--- a/esphome/components/web_server/__init__.py
+++ b/esphome/components/web_server/__init__.py
@@ -289,6 +289,9 @@ async def to_code(config):
     var = cg.new_Pvariable(config[CONF_ID], paren)
     await cg.register_component(var, config)
 
+    # Track controller registration for StaticVector sizing
+    CORE.register_controller()
+
     version = config[CONF_VERSION]
 
     cg.add(paren.set_port(config[CONF_PORT]))
diff --git a/esphome/core/__init__.py b/esphome/core/__init__.py
index fed5265d6b..84c9e36002 100644
--- a/esphome/core/__init__.py
+++ b/esphome/core/__init__.py
@@ -910,6 +910,11 @@ class EsphomeCore:
         """
         self.platform_counts[platform_name] += 1
 
+    def register_controller(self) -> None:
+        """Track registration of a Controller for ControllerRegistry StaticVector sizing."""
+        controller_count = self.data.setdefault("controller_registry_count", 0)
+        self.data["controller_registry_count"] = controller_count + 1
+
     @property
     def cpp_main_section(self):
         from esphome.cpp_generator import statement
diff --git a/esphome/core/config.py b/esphome/core/config.py
index 2740453808..3d98eda8bb 100644
--- a/esphome/core/config.py
+++ b/esphome/core/config.py
@@ -462,6 +462,15 @@ async def _add_platform_defines() -> None:
             cg.add_define(f"USE_{platform_name.upper()}")
 
 
+@coroutine_with_priority(CoroPriority.FINAL)
+async def _add_controller_registry_define() -> None:
+    # Generate StaticVector size for ControllerRegistry
+    controller_count = CORE.data.get("controller_registry_count", 0)
+    if controller_count > 0:
+        cg.add_define("USE_CONTROLLER_REGISTRY")
+        cg.add_define("CONTROLLER_REGISTRY_MAX", controller_count)
+
+
 @coroutine_with_priority(CoroPriority.CORE)
 async def to_code(config: ConfigType) -> None:
     cg.add_global(cg.global_ns.namespace("esphome").using)
diff --git a/esphome/core/controller_registry.cpp b/esphome/core/controller_registry.cpp
index b3f4c646a3..b22ec487d5 100644
--- a/esphome/core/controller_registry.cpp
+++ b/esphome/core/controller_registry.cpp
@@ -1,9 +1,12 @@
 #include "esphome/core/controller_registry.h"
+
+#ifdef USE_CONTROLLER_REGISTRY
+
 #include "esphome/core/controller.h"
 
 namespace esphome {
 
-std::vector<Controller *> ControllerRegistry::controllers;
+StaticVector<Controller *, CONTROLLER_REGISTRY_MAX> ControllerRegistry::controllers;
 
 void ControllerRegistry::register_controller(Controller *controller) { controllers.push_back(controller); }
 
@@ -168,3 +171,5 @@ void ControllerRegistry::notify_update(update::UpdateEntity *obj) {
 #endif
 
 }  // namespace esphome
+
+#endif  // USE_CONTROLLER_REGISTRY
diff --git a/esphome/core/controller_registry.h b/esphome/core/controller_registry.h
index 72485c356b..640a276a0a 100644
--- a/esphome/core/controller_registry.h
+++ b/esphome/core/controller_registry.h
@@ -1,7 +1,10 @@
 #pragma once
 
 #include "esphome/core/defines.h"
-#include <vector>
+
+#ifdef USE_CONTROLLER_REGISTRY
+
+#include "esphome/core/helpers.h"
 
 // Forward declarations
 namespace esphome {
@@ -234,7 +237,9 @@ class ControllerRegistry {
 #endif
 
  protected:
-  static std::vector<Controller *> controllers;
+  static StaticVector<Controller *, CONTROLLER_REGISTRY_MAX> controllers;
 };
 
 }  // namespace esphome
+
+#endif  // USE_CONTROLLER_REGISTRY
diff --git a/esphome/core/defines.h b/esphome/core/defines.h
index 2be32058ea..8230518071 100644
--- a/esphome/core/defines.h
+++ b/esphome/core/defines.h
@@ -28,6 +28,7 @@
 #define USE_BUTTON
 #define USE_CAMERA
 #define USE_CLIMATE
+#define USE_CONTROLLER_REGISTRY
 #define USE_COVER
 #define USE_DATETIME
 #define USE_DATETIME_DATE
@@ -296,6 +297,7 @@
 #define USE_DASHBOARD_IMPORT
 
 // Default counts for static analysis
+#define CONTROLLER_REGISTRY_MAX 2
 #define ESPHOME_COMPONENT_COUNT 50
 #define ESPHOME_DEVICE_COUNT 10
 #define ESPHOME_AREA_COUNT 10