ESP32-S3 Won't Compile in Arduino 2.2.1

[vicatcu]

The following sketch

#include <SoftwareSerial.h>

EspSoftwareSerial::UART testSerial;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  testSerial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:

}

Results in the following verbose compiler error outut:

In file included from /home/vic/Arduino/libraries/EspSoftwareSerial/src/SoftwareSerial.h:25,
                 from /tmp/.arduinoIDE-unsaved202391-25181-wzr2t0.fwh5m/sketch_oct1a/sketch_oct1a.ino:1:
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h: In constructor 'circular_queue<T, ForEachArg>::circular_queue(size_t)':
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:69:85: error: 'make_unique' is not a member of 'std'
     circular_queue(const size_t capacity) : m_bufSize(capacity + 1), m_buffer{ std::make_unique<T[]>(m_bufSize) }
                                                                                     ^~~~~~~~~~~
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:69:85: note: 'std::make_unique' is only available from C++14 onwards
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:69:98: error: expected primary-expression before '[' token
     circular_queue(const size_t capacity) : m_bufSize(capacity + 1), m_buffer{ std::make_unique<T[]>(m_bufSize) }
                                                                                                  ^
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:69:99: error: expected primary-expression before ']' token
     circular_queue(const size_t capacity) : m_bufSize(capacity + 1), m_buffer{ std::make_unique<T[]>(m_bufSize) }
                                                                                                   ^
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h: In member function 'bool circular_queue<T, ForEachArg>::capacity(size_t)':
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:270:40: error: 'make_unique' is not a member of 'std'
     std::unique_ptr<T[] > buffer{ std::make_unique<T[]>(cap + 1) };
                                        ^~~~~~~~~~~
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:270:40: note: 'std::make_unique' is only available from C++14 onwards
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:270:53: error: expected primary-expression before '[' token
     std::unique_ptr<T[] > buffer{ std::make_unique<T[]>(cap + 1) };
                                                     ^
/home/vic/Arduino/libraries/EspSoftwareSerial/src/circular_queue/circular_queue.h:270:54: error: expected primary-expression before ']' token
     std::unique_ptr<T[] > buffer{ std::make_unique<T[]>(cap + 1) };
                                                      ^

Using library EspSoftwareSerial at version 8.1.0 in folder: /home/vic/Arduino/libraries/EspSoftwareSerial 
exit status 1

Compilation error: exit status 1

[vicatcu]

I did some Googling and then decided to try some stuff. I was able to make a basic example compile by including the following code in a file called _make_unique.h in the circular_queue folder:

#ifndef ___MY_MAKE_UNIQUE___
#define ___MY_MAKE_UNIQUE___

#include <cstddef>
#include <memory>
#include <type_traits>
#include <utility>

namespace std {
    template<class T> struct _Unique_if {
        typedef unique_ptr<T> _Single_object;
    };

    template<class T> struct _Unique_if<T[]> {
        typedef unique_ptr<T[]> _Unknown_bound;
    };

    template<class T, size_t N> struct _Unique_if<T[N]> {
        typedef void _Known_bound;
    };

    template<class T, class... Args>
        typename _Unique_if<T>::_Single_object
        make_unique(Args&&... args) {
            return unique_ptr<T>(new T(std::forward<Args>(args)...));
        }

    template<class T>
        typename _Unique_if<T>::_Unknown_bound
        make_unique(size_t n) {
            typedef typename remove_extent<T>::type U;
            return unique_ptr<T>(new U[n]());
        }

    template<class T, class... Args>
        typename _Unique_if<T>::_Known_bound
        make_unique(Args&&...) = delete;
}
#endif

...and then adding #include "_make_unique.h" at the top of circular_queue/circular_queue.h.

The example that I wrote to see if it would compile is this:

#include <SoftwareSerial.h>
EspSoftwareSerial::UART swSerial;
EspSoftwareSerial::Config swSerialConfig = EspSoftwareSerial::SWSERIAL_8E1;

void setup() {
  Serial.begin(115200);
  swSerial.begin(9600, swSerialConfig, 10, 9, false, 128);
  delay(2000);
  Serial.println("Hello World");
}

void loop() {
  // put your main code here, to run repeatedly:
  if(Serial.available() > 0) {
    swSerial.write(Serial.read());
  }

  if(swSerial.available() > 0) {
    Serial.write(swSerial.read());
  }
}

I took inspiration from this SO post: https://stackoverflow.com/questions/24609271/errormake-unique-is-not-a-member-of-std which pointed me to this implementation https://en.cppreference.com/w/cpp/memory/unique_ptr/make_unique.

I'm not sure this is how you'd like to see this fixed, but let me know if you'd like me to make a PR.

[dok-net]

I'm sorry, I can't confirm. Currently, EspSoftwareSerial is ahead of the upcoming update of all ESP32 cores to IDF 5.1. I don't know which of the new chips are and which are not supported prior to IDF 5.1 anyway. As things are, the ghostl-async implementation that I'm focussed on is a part of EspSoftwareSerial, so if you think you needed to update EspSoftwareSerial - which you didn't as far as features are concerned - please checkout one of the latest IDF 5.1 based cores from Github, update the toolchains manually, and everything should compile just fine. I have built for ESP32S3 Dev Module successfully just this minute.

[vicatcu]

I've been advised that SoftwareSerial should be generally be avoided in ESP32 by Espressif folks in arduino-esp gitter.

[dok-net]

@vicatcu On what grounds, if I may ask? Generally speaking, it's always wrong to use SW serial unless it offers features that you don't get from the HW UARTs. Like, being available at all :-)

[dok-net]

HW serial doesn't work on ESP32 with current IDF 5.1 based Arduino core. Reverting to release 2.0.14 of course yields the make_unique issue you noticed.
I am reverting to the new operator in HEAD.

[vicatcu]

On the basis that there are 3 multiplexed hardware UARTs on the ESP32-S3 and if you only need to talk to one Serial input at a time you can just switch the pins a hardware UART at runtime by doing Serial.end followed by Serial.begin