[gps] Size the listener list at compile time (#21201)

esphome/components/gps/__init__.py

@@ -16,6 +16,7 @@ from esphome.const import (
     UNIT_KILOMETER_PER_HOUR,
     UNIT_METER,
 )
+from esphome.cpp_generator import MockObj
 from esphome.types import ConfigType
 
 CONF_GPS_ID = "gps_id"
@@ -40,6 +41,16 @@ GPS = gps_ns.class_("GPS", cg.PollingComponent, uart.UARTDevice)
 GPSListener = gps_ns.class_("GPSListener")
 
 MULTI_CONF = True
+
+_request_listener_slot = cg.slot_counter("GPS_LISTENER_COUNT")
+
+
+async def register_listener(hub: MockObj, var: MockObj) -> None:
+    """Register a listener with its GPS and count it for the compile-time list size."""
+    _request_listener_slot(str(hub))
+    cg.add(hub.register_listener(var))
+
+
 CONFIG_SCHEMA = cv.All(
     cv.Schema(
         {

esphome/components/gps/gps.cpp

@@ -84,9 +84,11 @@ void GPS::loop() {
       ESP_LOGV(TAG, "HDOP: %.3f", this->hdop_);
     }
 
+#ifdef GPS_LISTENER_COUNT
     for (auto *listener : this->listeners_) {
       listener->on_update(this->tiny_gps_);
     }
+#endif
   }
 }
 

esphome/components/gps/gps.h

@@ -3,10 +3,9 @@
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/components/uart/uart.h"
 #include "esphome/core/component.h"
+#include "esphome/core/helpers.h"
 #include <TinyGPSPlus.h>
 
-#include <vector>
-
 namespace esphome::gps {
 
 class GPS;
@@ -32,10 +31,12 @@ class GPS final : public PollingComponent, public uart::UARTDevice {
   void set_satellites_sensor(sensor::Sensor *satellites_sensor) { this->satellites_sensor_ = satellites_sensor; }
   void set_hdop_sensor(sensor::Sensor *hdop_sensor) { this->hdop_sensor_ = hdop_sensor; }
 
+#ifdef GPS_LISTENER_COUNT
   void register_listener(GPSListener *listener) {
     listener->parent_ = this;
     this->listeners_.push_back(listener);
   }
+#endif
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
   void dump_config() override;
@@ -63,7 +64,9 @@ class GPS final : public PollingComponent, public uart::UARTDevice {
   sensor::Sensor *hdop_sensor_{nullptr};
 
   TinyGPSPlus tiny_gps_;
-  std::vector<GPSListener *> listeners_{};
+#ifdef GPS_LISTENER_COUNT
+  StaticVector<GPSListener *, GPS_LISTENER_COUNT> listeners_;
+#endif
 };
 
 }  // namespace esphome::gps

esphome/components/gps/time/__init__.py

@@ -4,7 +4,7 @@ import esphome.config_validation as cv
 from esphome.const import CONF_ID
 from esphome.types import ConfigType
 
-from .. import CONF_GPS_ID, GPS, GPSListener, gps_ns
+from .. import CONF_GPS_ID, GPS, GPSListener, gps_ns, register_listener
 
 DEPENDENCIES = ["gps"]
 
@@ -26,4 +26,4 @@ async def to_code(config: ConfigType) -> None:
     await cg.register_component(var, config)
 
     paren = await cg.get_variable(config[CONF_GPS_ID])
-    cg.add(paren.register_listener(var))
+    await register_listener(paren, var)

esphome/core/defines.h

@@ -162,6 +162,7 @@
 #define USE_LVGL_TOUCHSCREEN
 #define USE_MDNS
 #define USE_MDNS_STORE_SERVICES
+#define GPS_LISTENER_COUNT 1
 #define HDMI_CEC_MESSAGE_CALLBACK_COUNT 2
 #define I2C_PORT_FREQUENCY_COUNT 1
 #define MDNS_SERVICE_COUNT 3