Keep get_name() working on ESP8266 with a RAM copy made on first use

esphome/components/mqtt/mqtt_component.cpp

@@ -413,9 +413,10 @@ void MQTTComponent::schedule_resend_state() { this->resend_state_ = true; }
 bool MQTTComponent::is_connected_() const { return global_mqtt_client->is_connected(); }
 
 // Pull these properties from EntityBase if not overridden
-#ifndef USE_ESP8266
-const StringRef &MQTTComponent::friendly_name_() const { return this->get_entity()->get_name_progmem().ram_ref(); }
-#endif
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+const StringRef &MQTTComponent::friendly_name_() const { return this->get_entity()->get_name(); }
+#pragma GCC diagnostic pop
 const LogString *MQTTComponent::log_name_() const { return this->get_entity()->get_log_name(); }
 StringRef MQTTComponent::get_default_object_id_to_(std::span<char, OBJECT_ID_MAX_LEN> buf) const {
   return this->get_entity()->get_object_id_to(buf);

esphome/components/mqtt/mqtt_component.h

@@ -300,10 +300,8 @@ class MQTTComponent : public Component {
 
   /// Entity name for a "%s" log argument.
   const LogString *log_name_() const;
-#ifndef USE_ESP8266
   ESPDEPRECATED("Use log_name_() for logging. Removed in 2027.5.0", "2026.11.0")
   const StringRef &friendly_name_() const;
-#endif
 
   /// Get the icon field of this component into a stack buffer
   const char *get_icon_to_(std::span<char, MAX_ICON_LENGTH> buf) const { return this->get_entity()->get_icon_to(buf); }

esphome/components/sprinkler/sprinkler.cpp

@@ -870,14 +870,15 @@ void Sprinkler::reset_resume() {
   this->resume_duration_.reset();
 }
 
-#ifndef USE_ESP8266
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 const char *Sprinkler::valve_name(const size_t valve_number) {
   if (this->is_a_valid_valve(valve_number)) {
-    return this->valve_[valve_number].controller_switch->get_name_progmem().ram_ref().c_str();
+    return this->valve_[valve_number].controller_switch->get_name().c_str();
   }
   return nullptr;
 }
-#endif
+#pragma GCC diagnostic pop
 
 const LogString *Sprinkler::valve_log_name(const size_t valve_number) {
   if (this->is_a_valid_valve(valve_number)) {

esphome/components/sprinkler/sprinkler.h

@@ -335,17 +335,9 @@ class Sprinkler final : public Component {
   /// resets resume state
   void reset_resume();
 
-#ifdef USE_ESP8266
-  template<typename T = int> const char *valve_name(size_t /*valve_number*/) {
-    static_assert(sizeof(T) == 0, "valve_name() unavailable on ESP8266 (name is in flash). Use valve_log_name() "
-                                  "for logging, or valve_switch()->get_name_to() for a copy.");
-    return nullptr;
-  }
-#else
   /// returns a pointer to a valve's name string object; returns nullptr if valve_number is invalid
   ESPDEPRECATED("Use valve_log_name() or valve_switch()->get_name_to() instead. Removed in 2027.5.0", "2026.11.0")
   const char *valve_name(size_t valve_number);
-#endif
   /// returns a valve's name for a "%s" log argument; returns nullptr if valve_number is invalid
   const LogString *valve_log_name(size_t valve_number);
 

esphome/core/entity_base.cpp

@@ -9,6 +9,38 @@ namespace esphome {
 
 ESPHOME_LOG_TAG(TAG, "entity_base");
 
+#ifdef USE_ESP8266
+namespace {
+// RAM copies made by the deprecated get_name(), only for entities whose name is asked for. Remove before 2027.5.0
+struct NameCopy {
+  NameCopy *next;
+  const char *key;
+  StringRef ref;
+};
+NameCopy *name_copies = nullptr;  // NOLINT(cppcoreguidelines-avoid-non-const-global-variables)
+const StringRef EMPTY_NAME;
+}  // namespace
+
+const StringRef &EntityBase::get_name() const {
+  const char *key = this->name_.progmem_ptr();
+  for (NameCopy *copy = name_copies; copy != nullptr; copy = copy->next) {
+    if (copy->key == key)
+      return copy->ref;
+  }
+  size_t len = this->name_.size();
+  auto *copy = static_cast<NameCopy *>(malloc(sizeof(NameCopy) + len + 1));  // NOLINT(cppcoreguidelines-no-malloc)
+  if (copy == nullptr)
+    return EMPTY_NAME;
+  char *buf = reinterpret_cast<char *>(copy + 1);
+  this->name_.write_to(buf, len + 1);
+  copy->next = name_copies;
+  copy->key = key;
+  copy->ref = StringRef(buf, len);
+  name_copies = copy;
+  return copy->ref;
+}
+#endif
+
 void EntityBase::configure_entity_(const char *name, uint32_t object_id_hash, uint32_t entity_fields) {
   this->name_ = ProgmemStringRef(name, ESPHOME_strlen_P(name));
   if (this->name_.empty()) {

esphome/core/entity_base.h

@@ -73,19 +73,16 @@ static constexpr uint8_t ENTITY_FIELD_ENTITY_CATEGORY_SHIFT = 26;
 // The generic Entity base class that provides an interface common to all Entities.
 class EntityBase {
  public:
+  // Remove before 2027.5.0
+  ESPDEPRECATED("Use get_name_to() or get_log_name() instead. Will be removed in ESPHome 2027.5.0", "2026.11.0")
 #ifdef USE_ESP8266
-  // On ESP8266 the name is in flash and cannot be read as a plain string.
-  template<typename T = int> StringRef get_name() const {
-    static_assert(sizeof(T) == 0, "get_name() unavailable on ESP8266 (name is in flash). "
-                                  "Use get_name_to() with a stack buffer, or get_log_name() for logging.");
-    return {};
-  }
+  /// The name is in flash here; the first call makes a RAM copy that is kept for the life of the device.
+  const StringRef &get_name() const;
   /// Get the name of this Entity, copied out of flash into buffer.
   StringRef get_name_to(std::span<char, ENTITY_NAME_BUF_SIZE> buffer) const {
     return StringRef(buffer.data(), this->write_name_to(buffer.data(), buffer.size()));
   }
 #else
-  ESPDEPRECATED("Use get_name_to() or get_log_name() instead. Will be removed in ESPHome 2027.5.0", "2026.11.0")
   const StringRef &get_name() const { return this->name_.ram_ref(); }
   const StringRef &get_name_to(std::span<char, ENTITY_NAME_BUF_SIZE> /*buffer*/) const { return this->name_.ram_ref(); }
 #endif