cleanup

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

esphome/__main__.py

@@ -1,5 +1,6 @@
 # PYTHON_ARGCOMPLETE_OK
 import argparse
+from collections.abc import Callable
 from datetime import datetime
 import functools
 import getpass
@@ -936,11 +937,21 @@ def command_dashboard(args: ArgsProtocol) -> int | None:
     return dashboard.start_dashboard(args)
 
 
-def command_update_all(args: ArgsProtocol) -> int | None:
+def run_multiple_configs(
+    files: list, command_builder: Callable[[str], list[str]]
+) -> int:
+    """Run a command for each configuration file in a subprocess.
+
+    Args:
+        files: List of configuration files to process.
+        command_builder: Callable that takes a file path and returns a command list.
+
+    Returns:
+        Number of failed files.
+    """
     import click
 
     success = {}
-    files = list_yaml_files(args.configuration)
     twidth = 60
 
     def print_bar(middle_text):
@@ -950,17 +961,19 @@ def command_update_all(args: ArgsProtocol) -> int | None:
         safe_print(f"{half_line}{middle_text}{half_line}")
 
     for f in files:
-        safe_print(f"Updating {color(AnsiFore.CYAN, str(f))}")
+        f_path = Path(f) if not isinstance(f, Path) else f
+
+        if any(f_path.name == x for x in SECRETS_FILES):
+            _LOGGER.warning("Skipping secrets file %s", f_path)
+            continue
+
+        safe_print(f"Processing {color(AnsiFore.CYAN, str(f))}")
         safe_print("-" * twidth)
         safe_print()
-        if CORE.dashboard:
-            rc = run_external_process(
-                "esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"
-            )
-        else:
-            rc = run_external_process(
-                "esphome", "run", f, "--no-logs", "--device", "OTA"
-            )
+
+        cmd = command_builder(f)
+        rc = run_external_process(*cmd)
+
         if rc == 0:
             print_bar(f"[{color(AnsiFore.BOLD_GREEN, 'SUCCESS')}] {str(f)}")
             success[f] = True
@@ -975,6 +988,8 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     print_bar(f"[{color(AnsiFore.BOLD_WHITE, 'SUMMARY')}]")
     failed = 0
     for f in files:
+        if f not in success:
+            continue  # Skipped file
         if success[f]:
             safe_print(f"  - {str(f)}: {color(AnsiFore.GREEN, 'SUCCESS')}")
         else:
@@ -983,6 +998,17 @@ def command_update_all(args: ArgsProtocol) -> int | None:
     return failed
 
 
+def command_update_all(args: ArgsProtocol) -> int | None:
+    files = list_yaml_files(args.configuration)
+
+    def build_command(f):
+        if CORE.dashboard:
+            return ["esphome", "--dashboard", "run", f, "--no-logs", "--device", "OTA"]
+        return ["esphome", "run", f, "--no-logs", "--device", "OTA"]
+
+    return run_multiple_configs(files, build_command)
+
+
 def command_idedata(args: ArgsProtocol, config: ConfigType) -> int:
     import json
 
@@ -1533,38 +1559,48 @@ def run_esphome(argv):
 
     _LOGGER.info("ESPHome %s", const.__version__)
 
-    for conf_path in args.configuration:
-        conf_path = Path(conf_path)
-        if any(conf_path.name == x for x in SECRETS_FILES):
-            _LOGGER.warning("Skipping secrets file %s", conf_path)
-            continue
+    # Multiple configurations: use subprocesses to avoid state leakage
+    # between compilations (e.g., LVGL touchscreen state in module globals)
+    if len(args.configuration) > 1:
+        # Build command by reusing argv, replacing all configs with single file
+        # argv[0] is the program path, skip it since we prefix with "esphome"
+        def build_command(f):
+            return (
+                ["esphome"]
+                + [arg for arg in argv[1:] if arg not in args.configuration]
+                + [str(f)]
+            )
 
-        CORE.config_path = conf_path
-        CORE.dashboard = args.dashboard
+        return run_multiple_configs(args.configuration, build_command)
 
-        # For logs command, skip updating external components
-        skip_external = args.command == "logs"
-        config = read_config(
-            dict(args.substitution) if args.substitution else {},
-            skip_external_update=skip_external,
-        )
-        if config is None:
-            return 2
-        CORE.config = config
+    # Single configuration
+    conf_path = Path(args.configuration[0])
+    if any(conf_path.name == x for x in SECRETS_FILES):
+        _LOGGER.warning("Skipping secrets file %s", conf_path)
+        return 0
 
-        if args.command not in POST_CONFIG_ACTIONS:
-            safe_print(f"Unknown command {args.command}")
+    CORE.config_path = conf_path
+    CORE.dashboard = args.dashboard
 
-        try:
-            rc = POST_CONFIG_ACTIONS[args.command](args, config)
-        except EsphomeError as e:
-            _LOGGER.error(e, exc_info=args.verbose)
-            return 1
-        if rc != 0:
-            return rc
+    # For logs command, skip updating external components
+    skip_external = args.command == "logs"
+    config = read_config(
+        dict(args.substitution) if args.substitution else {},
+        skip_external_update=skip_external,
+    )
+    if config is None:
+        return 2
+    CORE.config = config
 
-        CORE.reset()
-    return 0
+    if args.command not in POST_CONFIG_ACTIONS:
+        safe_print(f"Unknown command {args.command}")
+        return 1
+
+    try:
+        return POST_CONFIG_ACTIONS[args.command](args, config)
+    except EsphomeError as e:
+        _LOGGER.error(e, exc_info=args.verbose)
+        return 1
 
 
 def main():

esphome/codegen.py

@@ -69,6 +69,7 @@ from esphome.cpp_types import (  # noqa: F401
     JsonObjectConst,
     Parented,
     PollingComponent,
+    StringRef,
     arduino_json_ns,
     bool_,
     const_char_ptr,

esphome/components/anova/anova_base.cpp

@@ -18,31 +18,31 @@ AnovaPacket *AnovaCodec::clean_packet_() {
 
 AnovaPacket *AnovaCodec::get_read_device_status_request() {
   this->current_query_ = READ_DEVICE_STATUS;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DEVICE_STATUS);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DEVICE_STATUS);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_target_temp_request() {
   this->current_query_ = READ_TARGET_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_TARGET_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_TARGET_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_current_temp_request() {
   this->current_query_ = READ_CURRENT_TEMPERATURE;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_CURRENT_TEMP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_CURRENT_TEMP);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_unit_request() {
   this->current_query_ = READ_UNIT;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_UNIT);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_UNIT);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_read_data_request() {
   this->current_query_ = READ_DATA;
-  sprintf((char *) this->packet_.data, "%s", CMD_READ_DATA);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_READ_DATA);
   return this->clean_packet_();
 }
 
@@ -50,25 +50,25 @@ AnovaPacket *AnovaCodec::get_set_target_temp_request(float temperature) {
   this->current_query_ = SET_TARGET_TEMPERATURE;
   if (this->fahrenheit_)
     temperature = ctof(temperature);
-  sprintf((char *) this->packet_.data, CMD_SET_TARGET_TEMP, temperature);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TARGET_TEMP, temperature);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_set_unit_request(char unit) {
   this->current_query_ = SET_UNIT;
-  sprintf((char *) this->packet_.data, CMD_SET_TEMP_UNIT, unit);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), CMD_SET_TEMP_UNIT, unit);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_start_request() {
   this->current_query_ = START;
-  sprintf((char *) this->packet_.data, CMD_START);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_START);
   return this->clean_packet_();
 }
 
 AnovaPacket *AnovaCodec::get_stop_request() {
   this->current_query_ = STOP;
-  sprintf((char *) this->packet_.data, CMD_STOP);
+  snprintf((char *) this->packet_.data, sizeof(this->packet_.data), "%s", CMD_STOP);
   return this->clean_packet_();
 }
 

esphome/components/api/api_connection.cpp

@@ -1715,7 +1715,7 @@ void APIConnection::on_home_assistant_state_response(const HomeAssistantStateRes
     // HA state max length is 255 characters, but attributes can be much longer
     // Use stack buffer for common case (states), heap fallback for large attributes
     size_t state_len = msg.state.size();
-    SmallBufferWithHeapFallback<256> state_buf_alloc(state_len + 1);
+    SmallBufferWithHeapFallback<MAX_STATE_LEN + 1> state_buf_alloc(state_len + 1);
     char *state_buf = reinterpret_cast<char *>(state_buf_alloc.get());
     if (state_len > 0) {
       memcpy(state_buf, msg.state.c_str(), state_len);

esphome/components/cse7766/cse7766.cpp

@@ -207,20 +207,24 @@ void CSE7766Component::parse_data_() {
 
 #if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERY_VERBOSE
   {
-    std::string buf = "Parsed:";
+    // Buffer: 7 + 15 + 33 + 15 + 25 = 95 chars max + null, rounded to 128 for safety margin.
+    // Float sizes with %.4f can be up to 11 chars for large values (e.g., 999999.9999).
+    char buf[128];
+    size_t pos = buf_append_printf(buf, sizeof(buf), 0, "Parsed:");
     if (have_voltage) {
-      buf += str_sprintf(" V=%fV", voltage);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " V=%.4fV", voltage);
     }
     if (have_current) {
-      buf += str_sprintf(" I=%fmA (~%fmA)", current * 1000.0f, calculated_current * 1000.0f);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " I=%.4fmA (~%.4fmA)", current * 1000.0f,
+                              calculated_current * 1000.0f);
     }
     if (have_power) {
-      buf += str_sprintf(" P=%fW", power);
+      pos = buf_append_printf(buf, sizeof(buf), pos, " P=%.4fW", power);
     }
     if (energy != 0.0f) {
-      buf += str_sprintf(" E=%fkWh (%u)", energy, cf_pulses);
+      buf_append_printf(buf, sizeof(buf), pos, " E=%.4fkWh (%u)", energy, cf_pulses);
     }
-    ESP_LOGVV(TAG, "%s", buf.c_str());
+    ESP_LOGVV(TAG, "%s", buf);
   }
 #endif
 }

esphome/components/dfrobot_sen0395/commands.cpp

@@ -127,7 +127,9 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->min2_ = min2 = this->max2_ = max2 = this->min3_ = min3 = this->max3_ = max3 = this->min4_ = min4 =
         this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 %.0f %.0f", min1 / 0.15, max1 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f", min1 / 0.15, max1 / 0.15);
+    this->cmd_ = buf;
   } else if (min3 < 0 || max3 < 0) {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -135,7 +137,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->max2_ = max2 = round(max2 / 0.15) * 0.15;
     this->min3_ = min3 = this->max3_ = max3 = this->min4_ = min4 = this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15,
+             max2 / 0.15);
+    this->cmd_ = buf;
   } else if (min4 < 0 || max4 < 0) {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -145,9 +150,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->max3_ = max3 = round(max3 / 0.15) * 0.15;
     this->min4_ = min4 = this->max4_ = max4 = -1;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 "
-                             "%.0f %.0f %.0f %.0f %.0f %.0f",
-                             min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15, min2 / 0.15,
+             max2 / 0.15, min3 / 0.15, max3 / 0.15);
+    this->cmd_ = buf;
   } else {
     this->min1_ = min1 = round(min1 / 0.15) * 0.15;
     this->max1_ = max1 = round(max1 / 0.15) * 0.15;
@@ -158,10 +164,10 @@ DetRangeCfgCommand::DetRangeCfgCommand(float min1, float max1, float min2, float
     this->min4_ = min4 = round(min4 / 0.15) * 0.15;
     this->max4_ = max4 = round(max4 / 0.15) * 0.15;
 
-    this->cmd_ = str_sprintf("detRangeCfg -1 "
-                             "%.0f %.0f %.0f %.0f %.0f %.0f %.0f %.0f",
-                             min1 / 0.15, max1 / 0.15, min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15, min4 / 0.15,
-                             max4 / 0.15);
+    char buf[72];  // max 72: "detRangeCfg -1 "(15) + 8 * (float(5) + space(1)) + null
+    snprintf(buf, sizeof(buf), "detRangeCfg -1 %.0f %.0f %.0f %.0f %.0f %.0f %.0f %.0f", min1 / 0.15, max1 / 0.15,
+             min2 / 0.15, max2 / 0.15, min3 / 0.15, max3 / 0.15, min4 / 0.15, max4 / 0.15);
+    this->cmd_ = buf;
   }
 
   this->min1_ = min1;
@@ -203,7 +209,10 @@ SetLatencyCommand::SetLatencyCommand(float delay_after_detection, float delay_af
   delay_after_disappear = std::round(delay_after_disappear / 0.025f) * 0.025f;
   this->delay_after_detection_ = clamp(delay_after_detection, 0.0f, 1638.375f);
   this->delay_after_disappear_ = clamp(delay_after_disappear, 0.0f, 1638.375f);
-  this->cmd_ = str_sprintf("setLatency %.03f %.03f", this->delay_after_detection_, this->delay_after_disappear_);
+  // max 32: "setLatency "(11) + float(8) + " "(1) + float(8) + null, rounded to 32
+  char buf[32];
+  snprintf(buf, sizeof(buf), "setLatency %.03f %.03f", this->delay_after_detection_, this->delay_after_disappear_);
+  this->cmd_ = buf;
 };
 
 uint8_t SetLatencyCommand::on_message(std::string &message) {

esphome/components/dfrobot_sen0395/commands.h

@@ -75,8 +75,8 @@ class SetLatencyCommand : public Command {
 class SensorCfgStartCommand : public Command {
  public:
   SensorCfgStartCommand(bool startup_mode) : startup_mode_(startup_mode) {
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "sensorCfgStart %d", startup_mode);
+    char tmp_cmd[20];  // "sensorCfgStart " (15) + "0/1" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "sensorCfgStart %d", startup_mode);
     cmd_ = std::string(tmp_cmd);
   }
   uint8_t on_message(std::string &message) override;
@@ -142,8 +142,8 @@ class SensitivityCommand : public Command {
   SensitivityCommand(uint8_t sensitivity) : sensitivity_(sensitivity) {
     if (sensitivity > 9)
       sensitivity_ = sensitivity = 9;
-    char tmp_cmd[20] = {0};
-    sprintf(tmp_cmd, "setSensitivity %d", sensitivity);
+    char tmp_cmd[20];  // "setSensitivity " (15) + "0-9" (1) + null = 17
+    buf_append_printf(tmp_cmd, sizeof(tmp_cmd), 0, "setSensitivity %d", sensitivity);
     cmd_ = std::string(tmp_cmd);
   };
   uint8_t on_message(std::string &message) override;

esphome/components/event/__init__.py

@@ -90,9 +90,7 @@ async def setup_event_core_(var, config, *, event_types: list[str]):
 
     for conf in config.get(CONF_ON_EVENT, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(
-            trigger, [(cg.std_string, "event_type")], conf
-        )
+        await automation.build_automation(trigger, [(cg.StringRef, "event_type")], conf)
 
     cg.add(var.set_event_types(event_types))
 

esphome/components/event/automation.h

@@ -14,10 +14,10 @@ template<typename... Ts> class TriggerEventAction : public Action<Ts...>, public
   void play(const Ts &...x) override { this->parent_->trigger(this->event_type_.value(x...)); }
 };
 
-class EventTrigger : public Trigger<std::string> {
+class EventTrigger : public Trigger<StringRef> {
  public:
   EventTrigger(Event *event) {
-    event->add_on_event_callback([this](const std::string &event_type) { this->trigger(event_type); });
+    event->add_on_event_callback([this](StringRef event_type) { this->trigger(event_type); });
   }
 };
 

esphome/components/event/event.cpp

@@ -23,7 +23,7 @@ void Event::trigger(const std::string &event_type) {
   }
   this->last_event_type_ = found;
   ESP_LOGD(TAG, "'%s' >> '%s'", this->get_name().c_str(), this->last_event_type_);
-  this->event_callback_.call(event_type);
+  this->event_callback_.call(StringRef(found));
 #if defined(USE_EVENT) && defined(USE_CONTROLLER_REGISTRY)
   ControllerRegistry::notify_event(this);
 #endif
@@ -45,7 +45,7 @@ void Event::set_event_types(const std::vector<const char *> &event_types) {
   this->last_event_type_ = nullptr;  // Reset when types change
 }
 
-void Event::add_on_event_callback(std::function<void(const std::string &event_type)> &&callback) {
+void Event::add_on_event_callback(std::function<void(StringRef event_type)> &&callback) {
   this->event_callback_.add(std::move(callback));
 }
 

esphome/components/event/event.h

@@ -70,10 +70,10 @@ class Event : public EntityBase, public EntityBase_DeviceClass {
   /// Check if an event has been triggered.
   bool has_event() const { return this->last_event_type_ != nullptr; }
 
-  void add_on_event_callback(std::function<void(const std::string &event_type)> &&callback);
+  void add_on_event_callback(std::function<void(StringRef event_type)> &&callback);
 
  protected:
-  LazyCallbackManager<void(const std::string &event_type)> event_callback_;
+  LazyCallbackManager<void(StringRef event_type)> event_callback_;
   FixedVector<const char *> types_;
 
  private:

esphome/components/ezo/ezo.cpp

@@ -160,7 +160,7 @@ void EZOSensor::loop() {
   this->commands_.pop_front();
 }
 
-void EZOSensor::add_command_(const std::string &command, EzoCommandType command_type, uint16_t delay_ms) {
+void EZOSensor::add_command_(const char *command, EzoCommandType command_type, uint16_t delay_ms) {
   std::unique_ptr<EzoCommand> ezo_command(new EzoCommand);
   ezo_command->command = command;
   ezo_command->command_type = command_type;
@@ -169,13 +169,17 @@ void EZOSensor::add_command_(const std::string &command, EzoCommandType command_
 }
 
 void EZOSensor::set_calibration_point_(EzoCalibrationType type, float value) {
-  std::string payload = str_sprintf("Cal,%s,%0.2f", EZO_CALIBRATION_TYPE_STRINGS[type], value);
+  // max 21: "Cal,"(4) + type(4) + ","(1) + float(11) + null; use 24 for safety
+  char payload[24];
+  snprintf(payload, sizeof(payload), "Cal,%s,%0.2f", EZO_CALIBRATION_TYPE_STRINGS[type], value);
   this->add_command_(payload, EzoCommandType::EZO_CALIBRATION, 900);
 }
 
 void EZOSensor::set_address(uint8_t address) {
   if (address > 0 && address < 128) {
-    std::string payload = str_sprintf("I2C,%u", address);
+    // max 8: "I2C,"(4) + uint8(3) + null
+    char payload[8];
+    snprintf(payload, sizeof(payload), "I2C,%u", address);
     this->new_address_ = address;
     this->add_command_(payload, EzoCommandType::EZO_I2C);
   } else {
@@ -194,7 +198,9 @@ void EZOSensor::get_slope() { this->add_command_("Slope,?", EzoCommandType::EZO_
 void EZOSensor::get_t() { this->add_command_("T,?", EzoCommandType::EZO_T); }
 
 void EZOSensor::set_t(float value) {
-  std::string payload = str_sprintf("T,%0.2f", value);
+  // max 14 bytes: "T,"(2) + float with "%0.2f" (up to 11 chars) + null(1); use 16 for alignment
+  char payload[16];
+  snprintf(payload, sizeof(payload), "T,%0.2f", value);
   this->add_command_(payload, EzoCommandType::EZO_T);
 }
 
@@ -215,7 +221,9 @@ void EZOSensor::set_calibration_point_high(float value) {
 }
 
 void EZOSensor::set_calibration_generic(float value) {
-  std::string payload = str_sprintf("Cal,%0.2f", value);
+  // exact 16 bytes: "Cal," (4) + float with "%0.2f" (up to 11 chars, e.g. "-9999999.99") + null (1) = 16
+  char payload[16];
+  snprintf(payload, sizeof(payload), "Cal,%0.2f", value);
   this->add_command_(payload, EzoCommandType::EZO_CALIBRATION, 900);
 }
 
@@ -223,13 +231,11 @@ void EZOSensor::clear_calibration() { this->add_command_("Cal,clear", EzoCommand
 
 void EZOSensor::get_led_state() { this->add_command_("L,?", EzoCommandType::EZO_LED); }
 
-void EZOSensor::set_led_state(bool on) {
-  std::string to_send = "L,";
-  to_send += on ? "1" : "0";
-  this->add_command_(to_send, EzoCommandType::EZO_LED);
-}
+void EZOSensor::set_led_state(bool on) { this->add_command_(on ? "L,1" : "L,0", EzoCommandType::EZO_LED); }
 
-void EZOSensor::send_custom(const std::string &to_send) { this->add_command_(to_send, EzoCommandType::EZO_CUSTOM); }
+void EZOSensor::send_custom(const std::string &to_send) {
+  this->add_command_(to_send.c_str(), EzoCommandType::EZO_CUSTOM);
+}
 
 }  // namespace ezo
 }  // namespace esphome

esphome/components/ezo/ezo.h

@@ -92,7 +92,7 @@ class EZOSensor : public sensor::Sensor, public PollingComponent, public i2c::I2
   std::deque<std::unique_ptr<EzoCommand>> commands_;
   int new_address_;
 
-  void add_command_(const std::string &command, EzoCommandType command_type, uint16_t delay_ms = 300);
+  void add_command_(const char *command, EzoCommandType command_type, uint16_t delay_ms = 300);
 
   void set_calibration_point_(EzoCalibrationType type, float value);
 

esphome/components/fan/__init__.py

@@ -77,7 +77,7 @@ FanSpeedSetTrigger = fan_ns.class_(
     "FanSpeedSetTrigger", automation.Trigger.template(cg.int_)
 )
 FanPresetSetTrigger = fan_ns.class_(
-    "FanPresetSetTrigger", automation.Trigger.template(cg.std_string)
+    "FanPresetSetTrigger", automation.Trigger.template(cg.StringRef)
 )
 
 FanIsOnCondition = fan_ns.class_("FanIsOnCondition", automation.Condition.template())
@@ -287,7 +287,7 @@ async def setup_fan_core_(var, config):
         await automation.build_automation(trigger, [(cg.int_, "x")], conf)
     for conf in config.get(CONF_ON_PRESET_SET, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
-        await automation.build_automation(trigger, [(cg.std_string, "x")], conf)
+        await automation.build_automation(trigger, [(cg.StringRef, "x")], conf)
 
 
 async def register_fan(var, config):

esphome/components/fan/automation.h

@@ -208,7 +208,7 @@ class FanSpeedSetTrigger : public Trigger<int> {
   int last_speed_;
 };
 
-class FanPresetSetTrigger : public Trigger<std::string> {
+class FanPresetSetTrigger : public Trigger<StringRef> {
  public:
   FanPresetSetTrigger(Fan *state) {
     state->add_on_state_callback([this, state]() {
@@ -216,7 +216,7 @@ class FanPresetSetTrigger : public Trigger<std::string> {
       auto should_trigger = preset_mode != this->last_preset_mode_;
       this->last_preset_mode_ = preset_mode;
       if (should_trigger) {
-        this->trigger(std::string(preset_mode));
+        this->trigger(preset_mode);
       }
     });
     this->last_preset_mode_ = state->get_preset_mode();

esphome/components/gdk101/gdk101.cpp

@@ -163,9 +163,10 @@ bool GDK101Component::read_fw_version_(uint8_t *data) {
       return false;
     }
 
-    const std::string fw_version_str = str_sprintf("%d.%d", data[0], data[1]);
-
-    this->fw_version_text_sensor_->publish_state(fw_version_str);
+    // max 8: "255.255" (7 chars) + null
+    char buf[8];
+    snprintf(buf, sizeof(buf), "%d.%d", data[0], data[1]);
+    this->fw_version_text_sensor_->publish_state(buf);
   }
 #endif  // USE_TEXT_SENSOR
   return true;

esphome/components/mipi_spi/mipi_spi.h

@@ -224,12 +224,9 @@ class MipiSpi : public display::Display,
                     this->madctl_ & MADCTL_BGR ? "BGR" : "RGB", DISPLAYPIXEL * 8, IS_BIG_ENDIAN ? "Big" : "Little");
     if (this->brightness_.has_value())
       esph_log_config(TAG, "  Brightness: %u", this->brightness_.value());
-    if (this->cs_ != nullptr)
-      esph_log_config(TAG, "  CS Pin: %s", this->cs_->dump_summary().c_str());
-    if (this->reset_pin_ != nullptr)
-      esph_log_config(TAG, "  Reset Pin: %s", this->reset_pin_->dump_summary().c_str());
-    if (this->dc_pin_ != nullptr)
-      esph_log_config(TAG, "  DC Pin: %s", this->dc_pin_->dump_summary().c_str());
+    log_pin(TAG, "  CS Pin: ", this->cs_);
+    log_pin(TAG, "  Reset Pin: ", this->reset_pin_);
+    log_pin(TAG, "  DC Pin: ", this->dc_pin_);
     esph_log_config(TAG,
                     "  SPI Mode: %d\n"
                     "  SPI Data rate: %dMHz\n"

esphome/components/mipi_spi/models/adafruit.py

@@ -26,5 +26,3 @@ ST7789V.extend(
     reset_pin=40,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mipi_spi/models/amoled.py

@@ -105,6 +105,3 @@ CO5300 = DriverChip(
         (WCE, 0x00),
     ),
 )
-
-
-models = {}

esphome/components/mipi_spi/models/cyd.py

@@ -1,10 +1,45 @@
-from .ili import ILI9341
+from .ili import ILI9341, ILI9342, ST7789V
 
 ILI9341.extend(
+    # ESP32-2432S028 CYD board with Micro USB, has ILI9341 controller
     "ESP32-2432S028",
     data_rate="40MHz",
-    cs_pin=15,
-    dc_pin=2,
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
 )
 
-models = {}
+ST7789V.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ST7789V controller
+    "ESP32-2432S028-7789",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+)
+
+# fmt: off
+
+ILI9342.extend(
+    # ESP32-2432S028 CYD board with USB C + Micro USB, has ILI9342 controller
+    "ESP32-2432S028-9342",
+    data_rate="40MHz",
+    cs_pin={"number": 15, "ignore_strapping_warning": True},
+    dc_pin={"number": 2, "ignore_strapping_warning": True},
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x00, 0x0C, 0x11, 0x04, 0x11, 0x08, 0x37, 0x89, 0x4C, 0x06, 0x0C, 0x0A, 0x2E, 0x34, 0x0F),  # Positive Gamma Correction
+        (0xE1, 0x00, 0x0B, 0x11, 0x05, 0x13, 0x09, 0x33, 0x67, 0x48, 0x07, 0x0E, 0x0B, 0x23, 0x33, 0x0F),  # Negative Gamma Correction
+    )
+)

esphome/components/mipi_spi/models/ili.py

@@ -148,6 +148,34 @@ ILI9341 = DriverChip(
         ),
     ),
 )
+
+# fmt: off
+
+ILI9342 = DriverChip(
+    "ILI9342",
+    width=320,
+    height=240,
+    mirror_x=True,
+    initsequence=(
+        (0xCB, 0x39, 0x2C, 0x00, 0x34, 0x02),  # Power Control A
+        (0xCF, 0x00, 0xC1, 0x30),  # Power Control B
+        (0xE8, 0x85, 0x00, 0x78),  # Driver timing control A
+        (0xEA, 0x00, 0x00),  # Driver timing control B
+        (0xED, 0x64, 0x03, 0x12, 0x81),  # Power on sequence control
+        (0xF7, 0x20),  # Pump ratio control
+        (0xC0, 0x23),  # Power Control 1
+        (0xC1, 0x10),  # Power Control 2
+        (0xC5, 0x3E, 0x28),  # VCOM Control 1
+        (0xC7, 0x86),  # VCOM Control 2
+        (0xB1, 0x00, 0x1B),  # Frame Rate Control
+        (0xB6, 0x0A, 0xA2, 0x27, 0x00),  # Display Function Control
+        (0xF2, 0x00),  # Enable 3G
+        (0x26, 0x01),  # Gamma Set
+        (0xE0, 0x0F, 0x1F, 0x1C, 0x0C, 0x0F, 0x08, 0x48, 0x98, 0x37, 0x0A, 0x13, 0x04, 0x11, 0x0D, 0x00),  # Positive Gamma
+        (0xE1, 0x0F, 0x32, 0x2E, 0x0B, 0x0D, 0x05, 0x47, 0x75, 0x37, 0x06, 0x10, 0x03, 0x24, 0x20, 0x00),  # Negative Gamma
+    ),
+)
+
 # M5Stack Core2 uses ILI9341 chip - mirror_x disabled for correct orientation
 ILI9341.extend(
     "M5CORE2",
@@ -758,5 +786,3 @@ ST7796.extend(
     dc_pin=0,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mipi_spi/models/jc.py

@@ -588,5 +588,3 @@ DriverChip(
         (0x29, 0x00),
     ),
 )
-
-models = {}

esphome/components/mipi_spi/models/lanbon.py

@@ -11,5 +11,3 @@ ST7789V.extend(
     dc_pin=21,
     reset_pin=18,
 )
-
-models = {}

esphome/components/mipi_spi/models/lilygo.py

@@ -56,5 +56,3 @@ ST7796.extend(
     backlight_pin=48,
     invert_colors=True,
 )
-
-models = {}

esphome/components/mqtt/custom_mqtt_device.cpp

@@ -18,7 +18,7 @@ bool CustomMQTTDevice::publish(const std::string &topic, float value, int8_t num
 }
 bool CustomMQTTDevice::publish(const std::string &topic, int value) {
   char buffer[24];
-  size_t len = buf_append_printf(buffer, sizeof(buffer), 0, "%d", value);
+  int len = snprintf(buffer, sizeof(buffer), "%d", value);
   return global_mqtt_client->publish(topic, buffer, len);
 }
 bool CustomMQTTDevice::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos, bool retain) {

esphome/components/mqtt/mqtt_client.cpp

@@ -5,6 +5,7 @@
 #include <utility>
 #include "esphome/components/network/util.h"
 #include "esphome/core/application.h"
+#include "esphome/core/entity_base.h"
 #include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include "esphome/core/version.h"
@@ -66,10 +67,13 @@ void MQTTClientComponent::setup() {
         "esphome/discover", [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); },
         2);
 
-    std::string topic = "esphome/ping/";
-    topic.append(App.get_name());
+    // Format topic on stack - subscribe() copies it
+    // "esphome/ping/" (13) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+    constexpr size_t ping_topic_buffer_size = 13 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+    char ping_topic[ping_topic_buffer_size];
+    buf_append_printf(ping_topic, sizeof(ping_topic), 0, "esphome/ping/%s", App.get_name().c_str());
     this->subscribe(
-        topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
+        ping_topic, [this](const std::string &topic, const std::string &payload) { this->send_device_info_(); }, 2);
   }
 
   if (this->enable_on_boot_) {
@@ -81,8 +85,11 @@ void MQTTClientComponent::send_device_info_() {
   if (!this->is_connected() or !this->is_discovery_ip_enabled()) {
     return;
   }
-  std::string topic = "esphome/discover/";
-  topic.append(App.get_name());
+  // Format topic on stack to avoid heap allocation
+  // "esphome/discover/" (17) + name (ESPHOME_DEVICE_NAME_MAX_LEN) + null (1)
+  constexpr size_t topic_buffer_size = 17 + ESPHOME_DEVICE_NAME_MAX_LEN + 1;
+  char topic[topic_buffer_size];
+  buf_append_printf(topic, sizeof(topic), 0, "esphome/discover/%s", App.get_name().c_str());
 
   // NOLINTBEGIN(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   this->publish_json(
@@ -91,17 +98,7 @@ void MQTTClientComponent::send_device_info_() {
         uint8_t index = 0;
         for (auto &ip : network::get_ip_addresses()) {
           if (ip.is_set()) {
-            char key[8];  // "ip" + up to 3 digits + null
-            char ip_buf[network::IP_ADDRESS_BUFFER_SIZE];
-            if (index == 0) {
-              key[0] = 'i';
-              key[1] = 'p';
-              key[2] = '\0';
-            } else {
-              buf_append_printf(key, sizeof(key), 0, "ip%u", index);
-            }
-            ip.str_to(ip_buf);
-            root[key] = ip_buf;
+            root["ip" + (index == 0 ? "" : esphome::to_string(index))] = ip.str();
             index++;
           }
         }
@@ -510,39 +507,49 @@ bool MQTTClientComponent::publish(const std::string &topic, const std::string &p
 
 bool MQTTClientComponent::publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos,
                                   bool retain) {
-  return publish({.topic = topic, .payload = std::string(payload, payload_length), .qos = qos, .retain = retain});
+  return this->publish(topic.c_str(), payload, payload_length, qos, retain);
 }
 
 bool MQTTClientComponent::publish(const MQTTMessage &message) {
+  return this->publish(message.topic.c_str(), message.payload.c_str(), message.payload.length(), message.qos,
+                       message.retain);
+}
+bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
+                                       bool retain) {
+  return this->publish_json(topic.c_str(), f, qos, retain);
+}
+
+bool MQTTClientComponent::publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos,
+                                  bool retain) {
   if (!this->is_connected()) {
-    // critical components will re-transmit their messages
     return false;
   }
-  bool logging_topic = this->log_message_.topic == message.topic;
-  bool ret = this->mqtt_backend_.publish(message);
+  size_t topic_len = strlen(topic);
+  bool logging_topic = (topic_len == this->log_message_.topic.size()) &&
+                       (memcmp(this->log_message_.topic.c_str(), topic, topic_len) == 0);
+  bool ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
   delay(0);
   if (!ret && !logging_topic && this->is_connected()) {
     delay(0);
-    ret = this->mqtt_backend_.publish(message);
+    ret = this->mqtt_backend_.publish(topic, payload, payload_length, qos, retain);
     delay(0);
   }
 
   if (!logging_topic) {
     if (ret) {
-      ESP_LOGV(TAG, "Publish(topic='%s' payload='%s' retain=%d qos=%d)", message.topic.c_str(), message.payload.c_str(),
-               message.retain, message.qos);
+      ESP_LOGV(TAG, "Publish(topic='%s' retain=%d qos=%d)", topic, retain, qos);
+      ESP_LOGVV(TAG, "Publish payload (len=%u): '%.*s'", payload_length, static_cast<int>(payload_length), payload);
     } else {
-      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", message.topic.c_str(),
-               message.payload.length());
+      ESP_LOGV(TAG, "Publish failed for topic='%s' (len=%u). Will retry", topic, payload_length);
       this->status_momentary_warning("publish", 1000);
     }
   }
   return ret != 0;
 }
-bool MQTTClientComponent::publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos,
-                                       bool retain) {
+
+bool MQTTClientComponent::publish_json(const char *topic, const json::json_build_t &f, uint8_t qos, bool retain) {
   std::string message = json::build_json(f);
-  return this->publish(topic, message, qos, retain);
+  return this->publish(topic, message.c_str(), message.length(), qos, retain);
 }
 
 void MQTTClientComponent::enable() {

esphome/components/mqtt/mqtt_client.h

@@ -229,6 +229,9 @@ class MQTTClientComponent : public Component
   bool publish(const std::string &topic, const char *payload, size_t payload_length, uint8_t qos = 0,
                bool retain = false);
 
+  /// Publish directly without creating MQTTMessage (avoids heap allocation for topic)
+  bool publish(const char *topic, const char *payload, size_t payload_length, uint8_t qos = 0, bool retain = false);
+
   /** Construct and send a JSON MQTT message.
    *
    * @param topic The topic.
@@ -237,6 +240,9 @@ class MQTTClientComponent : public Component
    */
   bool publish_json(const std::string &topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
 
+  /// Publish JSON directly without heap allocation for topic
+  bool publish_json(const char *topic, const json::json_build_t &f, uint8_t qos = 0, bool retain = false);
+
   /// Setup the MQTT client, registering a bunch of callbacks and attempting to connect.
   void setup() override;
   void dump_config() override;

esphome/components/mqtt/mqtt_component.cpp

@@ -190,37 +190,27 @@ bool MQTTComponent::send_discovery_() {
         StringRef object_id = this->get_default_object_id_to_(object_id_buf);
         if (discovery_info.unique_id_generator == MQTT_MAC_ADDRESS_UNIQUE_ID_GENERATOR) {
           char friendly_name_hash[9];
-          buf_append_printf(friendly_name_hash, sizeof(friendly_name_hash), 0, "%08" PRIx32,
-                            fnv1_hash(this->friendly_name_()));
+          snprintf(friendly_name_hash, sizeof(friendly_name_hash), "%08" PRIx32, fnv1_hash(this->friendly_name_()));
           // Format: mac-component_type-hash (e.g. "aabbccddeeff-sensor-12345678")
           // MAC (12) + "-" (1) + domain (max 20) + "-" (1) + hash (8) + null (1) = 43
           char unique_id[MAC_ADDRESS_BUFFER_SIZE + ESPHOME_DOMAIN_MAX_LEN + 11];
           char mac_buf[MAC_ADDRESS_BUFFER_SIZE];
           get_mac_address_into_buffer(mac_buf);
-          buf_append_printf(unique_id, sizeof(unique_id), 0, "%s-%s-%s", mac_buf, this->component_type(),
-                            friendly_name_hash);
+          snprintf(unique_id, sizeof(unique_id), "%s-%s-%s", mac_buf, this->component_type(), friendly_name_hash);
           root[MQTT_UNIQUE_ID] = unique_id;
         } else {
           // default to almost-unique ID. It's a hack but the only way to get that
           // gorgeous device registry view.
-          // "ESP" (3) + component_type (max 20) + object_id (max 128) + null
-          char unique_id_buf[3 + MQTT_COMPONENT_TYPE_MAX_LEN + OBJECT_ID_MAX_LEN + 1];
-          buf_append_printf(unique_id_buf, sizeof(unique_id_buf), 0, "ESP%s%s", this->component_type(),
-                            object_id.c_str());
-          root[MQTT_UNIQUE_ID] = unique_id_buf;
+          root[MQTT_UNIQUE_ID] = "ESP" + std::string(this->component_type()) + object_id.c_str();
         }
 
         const std::string &node_name = App.get_name();
-        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR) {
-          // node_name (max 31) + "_" (1) + object_id (max 128) + null
-          char object_id_full[ESPHOME_DEVICE_NAME_MAX_LEN + 1 + OBJECT_ID_MAX_LEN + 1];
-          buf_append_printf(object_id_full, sizeof(object_id_full), 0, "%s_%s", node_name.c_str(), object_id.c_str());
-          root[MQTT_OBJECT_ID] = object_id_full;
-        }
+        if (discovery_info.object_id_generator == MQTT_DEVICE_NAME_OBJECT_ID_GENERATOR)
+          root[MQTT_OBJECT_ID] = node_name + "_" + object_id.c_str();
 
         const std::string &friendly_name_ref = App.get_friendly_name();
         const std::string &node_friendly_name = friendly_name_ref.empty() ? node_name : friendly_name_ref;
-        const char *node_area = App.get_area();
+        std::string node_area = App.get_area();
 
         JsonObject device_info = root[MQTT_DEVICE].to<JsonObject>();
         char mac[MAC_ADDRESS_BUFFER_SIZE];
@@ -231,29 +221,18 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_SW_VERSION] = ESPHOME_PROJECT_VERSION " (ESPHome " ESPHOME_VERSION ")";
         const char *model = std::strchr(ESPHOME_PROJECT_NAME, '.');
         device_info[MQTT_DEVICE_MODEL] = model == nullptr ? ESPHOME_BOARD : model + 1;
-        if (model == nullptr) {
-          device_info[MQTT_DEVICE_MANUFACTURER] = ESPHOME_PROJECT_NAME;
-        } else {
-          // Extract manufacturer (part before '.') using stack buffer to avoid heap allocation
-          // memcpy is used instead of strncpy since we know the exact length and strncpy
-          // would still require manual null-termination
-          char manufacturer[sizeof(ESPHOME_PROJECT_NAME)];
-          size_t len = model - ESPHOME_PROJECT_NAME;
-          memcpy(manufacturer, ESPHOME_PROJECT_NAME, len);
-          manufacturer[len] = '\0';
-          device_info[MQTT_DEVICE_MANUFACTURER] = manufacturer;
-        }
+        device_info[MQTT_DEVICE_MANUFACTURER] =
+            model == nullptr ? ESPHOME_PROJECT_NAME : std::string(ESPHOME_PROJECT_NAME, model - ESPHOME_PROJECT_NAME);
 #else
         static const char ver_fmt[] PROGMEM = ESPHOME_VERSION " (config hash 0x%08" PRIx32 ")";
-        // Buffer sized for format string expansion: ~4 bytes net growth from format specifier to 8 hex digits, plus
-        // safety margin
-        char version_buf[sizeof(ver_fmt) + 8];
 #ifdef USE_ESP8266
-        snprintf_P(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
+        char fmt_buf[sizeof(ver_fmt)];
+        strcpy_P(fmt_buf, ver_fmt);
+        const char *fmt = fmt_buf;
 #else
-        snprintf(version_buf, sizeof(version_buf), ver_fmt, App.get_config_hash());
+        const char *fmt = ver_fmt;
 #endif
-        device_info[MQTT_DEVICE_SW_VERSION] = version_buf;
+        device_info[MQTT_DEVICE_SW_VERSION] = str_sprintf(fmt, App.get_config_hash());
         device_info[MQTT_DEVICE_MODEL] = ESPHOME_BOARD;
 #if defined(USE_ESP8266) || defined(USE_ESP32)
         device_info[MQTT_DEVICE_MANUFACTURER] = "Espressif";
@@ -267,7 +246,7 @@ bool MQTTComponent::send_discovery_() {
         device_info[MQTT_DEVICE_MANUFACTURER] = "Host";
 #endif
 #endif
-        if (node_area[0] != '\0') {
+        if (!node_area.empty()) {
           device_info[MQTT_DEVICE_SUGGESTED_AREA] = node_area;
         }
 

esphome/components/mqtt/mqtt_fan.cpp

@@ -175,7 +175,7 @@ bool MQTTFanComponent::publish_state() {
   auto traits = this->state_->get_traits();
   if (traits.supports_speed()) {
     char buf[12];
-    size_t len = buf_append_printf(buf, sizeof(buf), 0, "%d", this->state_->speed);
+    int len = snprintf(buf, sizeof(buf), "%d", this->state_->speed);
     bool success = this->publish(this->get_speed_level_state_topic(), buf, len);
     failed = failed || !success;
   }

esphome/components/mqtt/mqtt_number.cpp

@@ -75,7 +75,7 @@ bool MQTTNumberComponent::send_initial_state() {
 }
 bool MQTTNumberComponent::publish_state(float value) {
   char buffer[64];
-  buf_append_printf(buffer, sizeof(buffer), 0, "%f", value);
+  snprintf(buffer, sizeof(buffer), "%f", value);
   return this->publish(this->get_state_topic_(), buffer);
 }
 

esphome/components/pipsolar/output/pipsolar_output.cpp

@@ -8,7 +8,7 @@ namespace pipsolar {
 static const char *const TAG = "pipsolar.output";
 
 void PipsolarOutput::write_state(float state) {
-  char tmp[10];
+  char tmp[16];
   snprintf(tmp, sizeof(tmp), this->set_command_, state);
 
   if (std::find(this->possible_values_.begin(), this->possible_values_.end(), state) != this->possible_values_.end()) {

esphome/components/select/__init__.py

@@ -33,7 +33,7 @@ SelectPtr = Select.operator("ptr")
 # Triggers
 SelectStateTrigger = select_ns.class_(
     "SelectStateTrigger",
-    automation.Trigger.template(cg.std_string, cg.size_t),
+    automation.Trigger.template(cg.StringRef, cg.size_t),
 )
 
 # Actions
@@ -100,7 +100,7 @@ async def setup_select_core_(var, config, *, options: list[str]):
     for conf in config.get(CONF_ON_VALUE, []):
         trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
         await automation.build_automation(
-            trigger, [(cg.std_string, "x"), (cg.size_t, "i")], conf
+            trigger, [(cg.StringRef, "x"), (cg.size_t, "i")], conf
         )
 
     if (mqtt_id := config.get(CONF_MQTT_ID)) is not None:

esphome/components/select/automation.h

@@ -6,11 +6,11 @@
 
 namespace esphome::select {
 
-class SelectStateTrigger : public Trigger<std::string, size_t> {
+class SelectStateTrigger : public Trigger<StringRef, size_t> {
  public:
   explicit SelectStateTrigger(Select *parent) : parent_(parent) {
     parent->add_on_state_callback(
-        [this](size_t index) { this->trigger(std::string(this->parent_->option_at(index)), index); });
+        [this](size_t index) { this->trigger(StringRef(this->parent_->option_at(index)), index); });
   }
 
  protected:

esphome/components/sim800l/sim800l.cpp

@@ -1,4 +1,5 @@
 #include "sim800l.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 #include <cstring>
 
@@ -50,8 +51,8 @@ void Sim800LComponent::update() {
   } else if (state_ == STATE_RECEIVED_SMS) {
     // Serial Buffer should have flushed.
     // Send cmd to delete received sms
-    char delete_cmd[20];
-    sprintf(delete_cmd, "AT+CMGD=%d", this->parse_index_);
+    char delete_cmd[20];  // "AT+CMGD=" (8) + uint8_t (max 3) + null = 12 <= 20
+    buf_append_printf(delete_cmd, sizeof(delete_cmd), 0, "AT+CMGD=%d", this->parse_index_);
     this->send_cmd_(delete_cmd);
     this->state_ = STATE_CHECK_SMS;
     this->expect_ack_ = true;

esphome/components/template/select/__init__.py

@@ -88,5 +88,5 @@ async def to_code(config):
 
     if CONF_SET_ACTION in config:
         await automation.build_automation(
-            var.get_set_trigger(), [(cg.std_string, "x")], config[CONF_SET_ACTION]
+            var.get_set_trigger(), [(cg.StringRef, "x")], config[CONF_SET_ACTION]
         )

esphome/components/template/select/template_select.cpp

@@ -41,7 +41,7 @@ void TemplateSelect::update() {
 }
 
 void TemplateSelect::control(size_t index) {
-  this->set_trigger_->trigger(std::string(this->option_at(index)));
+  this->set_trigger_->trigger(StringRef(this->option_at(index)));
 
   if (this->optimistic_)
     this->publish_state(index);

esphome/components/template/select/template_select.h

@@ -4,6 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/string_ref.h"
 #include "esphome/core/template_lambda.h"
 
 namespace esphome::template_ {
@@ -17,7 +18,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   void dump_config() override;
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
-  Trigger<std::string> *get_set_trigger() const { return this->set_trigger_; }
+  Trigger<StringRef> *get_set_trigger() const { return this->set_trigger_; }
   void set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
   void set_initial_option_index(size_t initial_option_index) { this->initial_option_index_ = initial_option_index; }
   void set_restore_value(bool restore_value) { this->restore_value_ = restore_value; }
@@ -27,7 +28,7 @@ class TemplateSelect final : public select::Select, public PollingComponent {
   bool optimistic_ = false;
   size_t initial_option_index_{0};
   bool restore_value_ = false;
-  Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
+  Trigger<StringRef> *set_trigger_ = new Trigger<StringRef>();
   TemplateLambda<std::string> f_;
 
   ESPPreferenceObject pref_;

esphome/components/toshiba/toshiba.cpp

@@ -1,5 +1,6 @@
 #include "toshiba.h"
 #include "esphome/components/remote_base/toshiba_ac_protocol.h"
+#include "esphome/core/helpers.h"
 
 #include <vector>
 
@@ -427,10 +428,17 @@ void ToshibaClimate::setup() {
   // Never send nan to HA
   if (std::isnan(this->target_temperature))
     this->target_temperature = 24;
+#if ESPHOME_LOG_LEVEL >= ESPHOME_LOG_LEVEL_VERBOSE
   // Log final state for debugging HA errors
-  ESP_LOGV(TAG, "Setup complete - Mode: %d, Fan: %s, Swing: %d, Temp: %.1f", static_cast<int>(this->mode),
-           this->fan_mode.has_value() ? std::to_string(static_cast<int>(this->fan_mode.value())).c_str() : "NONE",
+  const char *fan_mode_str = "NONE";
+  char fan_mode_buf[4];  // max 3 digits for fan mode enum + null
+  if (this->fan_mode.has_value()) {
+    buf_append_printf(fan_mode_buf, sizeof(fan_mode_buf), 0, "%d", static_cast<int>(this->fan_mode.value()));
+    fan_mode_str = fan_mode_buf;
+  }
+  ESP_LOGV(TAG, "Setup complete - Mode: %d, Fan: %s, Swing: %d, Temp: %.1f", static_cast<int>(this->mode), fan_mode_str,
            static_cast<int>(this->swing_mode), this->target_temperature);
+#endif
 }
 
 void ToshibaClimate::transmit_state() {

esphome/components/wl_134/wl_134.cpp

@@ -1,4 +1,5 @@
 #include "wl_134.h"
+#include "esphome/core/helpers.h"
 #include "esphome/core/log.h"
 
 #include <cinttypes>
@@ -78,8 +79,8 @@ Wl134Component::Rfid134Error Wl134Component::read_packet_() {
            reading.id, reading.country, reading.isData ? "true" : "false", reading.isAnimal ? "true" : "false",
            reading.reserved0, reading.reserved1);
 
-  char buf[20];
-  sprintf(buf, "%03d%012lld", reading.country, reading.id);
+  char buf[20];  // "%03d" (3) + "%012" PRId64 (12) + null = 16 max
+  buf_append_printf(buf, sizeof(buf), 0, "%03d%012" PRId64, reading.country, reading.id);
   this->publish_state(buf);
   if (this->do_reset_) {
     this->set_timeout(1000, [this]() { this->publish_state(""); });

esphome/core/scheduler.h

@@ -403,7 +403,9 @@ class Scheduler {
       for (size_t i = 0; i < remaining; i++) {
         this->defer_queue_[i] = std::move(this->defer_queue_[this->defer_queue_front_ + i]);
       }
-      this->defer_queue_.resize(remaining);
+      // Use erase() instead of resize() to avoid instantiating _M_default_append
+      // (saves ~156 bytes flash). Erasing from the end is O(1) - no shifting needed.
+      this->defer_queue_.erase(this->defer_queue_.begin() + remaining, this->defer_queue_.end());
     }
     this->defer_queue_front_ = 0;
   }

esphome/core/string_ref.h

@@ -72,6 +72,7 @@ class StringRef {
 
   constexpr const char *c_str() const { return base_; }
   constexpr size_type size() const { return len_; }
+  constexpr size_type length() const { return len_; }
   constexpr bool empty() const { return len_ == 0; }
   constexpr const_reference operator[](size_type pos) const { return *(base_ + pos); }
 
@@ -80,6 +81,32 @@ class StringRef {
 
   operator std::string() const { return str(); }
 
+  /// Find first occurrence of substring, returns std::string::npos if not found.
+  /// Note: Requires the underlying string to be null-terminated.
+  size_type find(const char *s, size_type pos = 0) const {
+    if (pos >= len_)
+      return std::string::npos;
+    const char *result = std::strstr(base_ + pos, s);
+    // Verify entire match is within bounds (strstr searches to null terminator)
+    if (result && result + std::strlen(s) <= base_ + len_)
+      return static_cast<size_type>(result - base_);
+    return std::string::npos;
+  }
+  size_type find(char c, size_type pos = 0) const {
+    if (pos >= len_)
+      return std::string::npos;
+    const void *result = std::memchr(base_ + pos, static_cast<unsigned char>(c), len_ - pos);
+    return result ? static_cast<size_type>(static_cast<const char *>(result) - base_) : std::string::npos;
+  }
+
+  /// Return substring as std::string
+  std::string substr(size_type pos = 0, size_type count = std::string::npos) const {
+    if (pos >= len_)
+      return std::string();
+    size_type actual_count = (count == std::string::npos || pos + count > len_) ? len_ - pos : count;
+    return std::string(base_ + pos, actual_count);
+  }
+
  private:
   const char *base_;
   size_type len_;
@@ -160,6 +187,43 @@ inline std::string operator+(const std::string &lhs, const StringRef &rhs) {
   str.append(rhs.c_str(), rhs.size());
   return str;
 }
+// String conversion functions for ADL compatibility (allows stoi(x) where x is StringRef)
+// Must be in esphome namespace for ADL to find them. Uses strtol/strtod directly to avoid heap allocation.
+namespace internal {
+// NOLINTBEGIN(google-runtime-int)
+template<typename R, typename F> inline R parse_number(const StringRef &str, size_t *pos, F conv) {
+  char *end;
+  R result = conv(str.c_str(), &end);
+  // Set pos to 0 on conversion failure (when no characters consumed), otherwise index after number
+  if (pos)
+    *pos = (end == str.c_str()) ? 0 : static_cast<size_t>(end - str.c_str());
+  return result;
+}
+template<typename R, typename F> inline R parse_number(const StringRef &str, size_t *pos, int base, F conv) {
+  char *end;
+  R result = conv(str.c_str(), &end, base);
+  // Set pos to 0 on conversion failure (when no characters consumed), otherwise index after number
+  if (pos)
+    *pos = (end == str.c_str()) ? 0 : static_cast<size_t>(end - str.c_str());
+  return result;
+}
+// NOLINTEND(google-runtime-int)
+}  // namespace internal
+// NOLINTBEGIN(readability-identifier-naming,google-runtime-int)
+inline int stoi(const StringRef &str, size_t *pos = nullptr, int base = 10) {
+  return static_cast<int>(internal::parse_number<long>(str, pos, base, std::strtol));
+}
+inline long stol(const StringRef &str, size_t *pos = nullptr, int base = 10) {
+  return internal::parse_number<long>(str, pos, base, std::strtol);
+}
+inline float stof(const StringRef &str, size_t *pos = nullptr) {
+  return internal::parse_number<float>(str, pos, std::strtof);
+}
+inline double stod(const StringRef &str, size_t *pos = nullptr) {
+  return internal::parse_number<double>(str, pos, std::strtod);
+}
+// NOLINTEND(readability-identifier-naming,google-runtime-int)
+
 #ifdef USE_JSON
 // NOLINTNEXTLINE(readability-identifier-naming)
 inline void convertToJson(const StringRef &src, JsonVariant dst) { dst.set(src.c_str()); }

esphome/cpp_types.py

@@ -44,3 +44,4 @@ gpio_Flags = gpio_ns.enum("Flags", is_class=True)
 EntityCategory = esphome_ns.enum("EntityCategory")
 Parented = esphome_ns.class_("Parented")
 ESPTime = esphome_ns.struct("ESPTime")
+StringRef = esphome_ns.class_("StringRef")

tests/integration/fixtures/select_stringref_trigger.yaml

@@ -0,0 +1,85 @@
+esphome:
+  name: select-stringref-test
+  friendly_name: Select StringRef Test
+
+host:
+
+logger:
+  level: DEBUG
+
+api:
+
+select:
+  - platform: template
+    name: "Test Select"
+    id: test_select
+    optimistic: true
+    options:
+      - "Option A"
+      - "Option B"
+      - "Option C"
+    initial_option: "Option A"
+    on_value:
+      then:
+        # Test 1: Log the value directly (StringRef -> const char* via c_str())
+        - logger.log:
+            format: "Select value: %s"
+            args: ['x.c_str()']
+        # Test 2: String concatenation (StringRef + const char* -> std::string)
+        - lambda: |-
+            std::string with_suffix = x + " selected";
+            ESP_LOGI("test", "Concatenated: %s", with_suffix.c_str());
+        # Test 3: Comparison (StringRef == const char*)
+        - lambda: |-
+            if (x == "Option B") {
+              ESP_LOGI("test", "Option B was selected");
+            }
+        # Test 4: Use index parameter (variable name is 'i')
+        - lambda: |-
+            ESP_LOGI("test", "Select index: %d", (int)i);
+        # Test 5: StringRef.length() method
+        - lambda: |-
+            ESP_LOGI("test", "Length: %d", (int)x.length());
+        # Test 6: StringRef.find() method with substring
+        - lambda: |-
+            if (x.find("Option") != std::string::npos) {
+              ESP_LOGI("test", "Found 'Option' in value");
+            }
+        # Test 7: StringRef.find() method with character
+        - lambda: |-
+            size_t space_pos = x.find(' ');
+            if (space_pos != std::string::npos) {
+              ESP_LOGI("test", "Space at position: %d", (int)space_pos);
+            }
+        # Test 8: StringRef.substr() method
+        - lambda: |-
+            std::string prefix = x.substr(0, 6);
+            ESP_LOGI("test", "Substr prefix: %s", prefix.c_str());
+
+  # Second select with numeric options to test ADL functions
+  - platform: template
+    name: "Baud Rate"
+    id: baud_select
+    optimistic: true
+    options:
+      - "9600"
+      - "115200"
+    initial_option: "9600"
+    on_value:
+      then:
+        # Test 9: stoi via ADL
+        - lambda: |-
+            int baud = stoi(x);
+            ESP_LOGI("test", "stoi result: %d", baud);
+        # Test 10: stol via ADL
+        - lambda: |-
+            long baud_long = stol(x);
+            ESP_LOGI("test", "stol result: %ld", baud_long);
+        # Test 11: stof via ADL
+        - lambda: |-
+            float baud_float = stof(x);
+            ESP_LOGI("test", "stof result: %.0f", baud_float);
+        # Test 12: stod via ADL
+        - lambda: |-
+            double baud_double = stod(x);
+            ESP_LOGI("test", "stod result: %.0f", baud_double);

tests/integration/test_select_stringref_trigger.py

@@ -0,0 +1,143 @@
+"""Integration test for select on_value trigger with StringRef parameter."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_select_stringref_trigger(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test select on_value trigger passes StringRef that works with string operations."""
+    loop = asyncio.get_running_loop()
+
+    # Track log messages to verify StringRef operations work
+    value_logged_future = loop.create_future()
+    concatenated_future = loop.create_future()
+    comparison_future = loop.create_future()
+    index_logged_future = loop.create_future()
+    length_future = loop.create_future()
+    find_substr_future = loop.create_future()
+    find_char_future = loop.create_future()
+    substr_future = loop.create_future()
+    # ADL functions
+    stoi_future = loop.create_future()
+    stol_future = loop.create_future()
+    stof_future = loop.create_future()
+    stod_future = loop.create_future()
+
+    # Patterns to match in logs
+    value_pattern = re.compile(r"Select value: Option B")
+    concatenated_pattern = re.compile(r"Concatenated: Option B selected")
+    comparison_pattern = re.compile(r"Option B was selected")
+    index_pattern = re.compile(r"Select index: 1")
+    length_pattern = re.compile(r"Length: 8")  # "Option B" is 8 chars
+    find_substr_pattern = re.compile(r"Found 'Option' in value")
+    find_char_pattern = re.compile(r"Space at position: 6")  # space at index 6
+    substr_pattern = re.compile(r"Substr prefix: Option")
+    # ADL function patterns (115200 from baud rate select)
+    stoi_pattern = re.compile(r"stoi result: 115200")
+    stol_pattern = re.compile(r"stol result: 115200")
+    stof_pattern = re.compile(r"stof result: 115200")
+    stod_pattern = re.compile(r"stod result: 115200")
+
+    def check_output(line: str) -> None:
+        """Check log output for expected messages."""
+        if not value_logged_future.done() and value_pattern.search(line):
+            value_logged_future.set_result(True)
+        if not concatenated_future.done() and concatenated_pattern.search(line):
+            concatenated_future.set_result(True)
+        if not comparison_future.done() and comparison_pattern.search(line):
+            comparison_future.set_result(True)
+        if not index_logged_future.done() and index_pattern.search(line):
+            index_logged_future.set_result(True)
+        if not length_future.done() and length_pattern.search(line):
+            length_future.set_result(True)
+        if not find_substr_future.done() and find_substr_pattern.search(line):
+            find_substr_future.set_result(True)
+        if not find_char_future.done() and find_char_pattern.search(line):
+            find_char_future.set_result(True)
+        if not substr_future.done() and substr_pattern.search(line):
+            substr_future.set_result(True)
+        # ADL functions
+        if not stoi_future.done() and stoi_pattern.search(line):
+            stoi_future.set_result(True)
+        if not stol_future.done() and stol_pattern.search(line):
+            stol_future.set_result(True)
+        if not stof_future.done() and stof_pattern.search(line):
+            stof_future.set_result(True)
+        if not stod_future.done() and stod_pattern.search(line):
+            stod_future.set_result(True)
+
+    async with (
+        run_compiled(yaml_config, line_callback=check_output),
+        api_client_connected() as client,
+    ):
+        # Verify device info
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "select-stringref-test"
+
+        # List entities to find our select
+        entities, _ = await client.list_entities_services()
+
+        select_entity = next(
+            (e for e in entities if hasattr(e, "options") and e.name == "Test Select"),
+            None,
+        )
+        assert select_entity is not None, "Test Select entity not found"
+
+        baud_entity = next(
+            (e for e in entities if hasattr(e, "options") and e.name == "Baud Rate"),
+            None,
+        )
+        assert baud_entity is not None, "Baud Rate entity not found"
+
+        # Change select to Option B - this should trigger on_value with StringRef
+        client.select_command(select_entity.key, "Option B")
+        # Change baud to 115200 - this tests ADL functions (stoi, stol, stof, stod)
+        client.select_command(baud_entity.key, "115200")
+
+        # Wait for all log messages confirming StringRef operations work
+        try:
+            await asyncio.wait_for(
+                asyncio.gather(
+                    value_logged_future,
+                    concatenated_future,
+                    comparison_future,
+                    index_logged_future,
+                    length_future,
+                    find_substr_future,
+                    find_char_future,
+                    substr_future,
+                    stoi_future,
+                    stol_future,
+                    stof_future,
+                    stod_future,
+                ),
+                timeout=5.0,
+            )
+        except TimeoutError:
+            results = {
+                "value_logged": value_logged_future.done(),
+                "concatenated": concatenated_future.done(),
+                "comparison": comparison_future.done(),
+                "index_logged": index_logged_future.done(),
+                "length": length_future.done(),
+                "find_substr": find_substr_future.done(),
+                "find_char": find_char_future.done(),
+                "substr": substr_future.done(),
+                "stoi": stoi_future.done(),
+                "stol": stol_future.done(),
+                "stof": stof_future.done(),
+                "stod": stod_future.done(),
+            }
+            pytest.fail(f"StringRef operations failed - received: {results}")

tests/unit_tests/test_main.py

@@ -34,6 +34,7 @@ from esphome.__main__ import (
     has_non_ip_address,
     has_resolvable_address,
     mqtt_get_ip,
+    run_esphome,
     run_miniterm,
     show_logs,
     upload_program,
@@ -1988,7 +1989,7 @@ esp32:
     clean_output = strip_ansi_codes(captured.out)
 
     assert "test-device_123.yaml" in clean_output
-    assert "Updating" in clean_output
+    assert "Processing" in clean_output
     assert "SUCCESS" in clean_output
     assert "SUMMARY" in clean_output
 
@@ -3172,3 +3173,66 @@ def test_run_miniterm_buffer_limit_prevents_unbounded_growth() -> None:
     x_count = printed_line.count("X")
     assert x_count < 150, f"Expected truncation but got {x_count} X's"
     assert x_count == 95, f"Expected 95 X's after truncation but got {x_count}"
+
+
+def test_run_esphome_multiple_configs_with_secrets(
+    tmp_path: Path,
+    mock_run_external_process: Mock,
+    capfd: CaptureFixture[str],
+    caplog: pytest.LogCaptureFixture,
+) -> None:
+    """Test run_esphome with multiple configs and secrets file.
+
+    Verifies:
+    - Multiple configs use subprocess isolation
+    - Secrets files are skipped with warning
+    - Secrets files don't appear in summary
+    """
+    # Create two config files and a secrets file
+    yaml_file1 = tmp_path / "device1.yaml"
+    yaml_file1.write_text("""
+esphome:
+  name: device1
+
+esp32:
+  board: nodemcu-32s
+""")
+    yaml_file2 = tmp_path / "device2.yaml"
+    yaml_file2.write_text("""
+esphome:
+  name: device2
+
+esp32:
+  board: nodemcu-32s
+""")
+    secrets_file = tmp_path / "secrets.yaml"
+    secrets_file.write_text("wifi_password: secret123\n")
+
+    setup_core(tmp_path=tmp_path)
+    mock_run_external_process.return_value = 0
+
+    # run_esphome expects argv[0] to be the program name (gets sliced off by parse_args)
+    with caplog.at_level(logging.WARNING):
+        result = run_esphome(
+            ["esphome", "compile", str(yaml_file1), str(secrets_file), str(yaml_file2)]
+        )
+
+    assert result == 0
+
+    # Check secrets file was skipped with warning
+    assert "Skipping secrets file" in caplog.text
+    assert "secrets.yaml" in caplog.text
+
+    captured = capfd.readouterr()
+    clean_output = strip_ansi_codes(captured.out)
+
+    # Both config files should be processed
+    assert "device1.yaml" in clean_output
+    assert "device2.yaml" in clean_output
+    assert "SUMMARY" in clean_output
+
+    # Secrets should not appear in summary
+    summary_section = (
+        clean_output.split("SUMMARY")[1] if "SUMMARY" in clean_output else ""
+    )
+    assert "secrets.yaml" not in summary_section