compile the c++ amqp-cpp demo program err, make err

Question

I want to write a test program with amqpcppCopernicaMarketingSoftware/AMQP-CPP. But the compiler(g++) complains:

g++ main.cpp rabbitmq_handler.cpp -std=c++11 -lamqpcpp -lpthread -ldl
In file included from /usr/local/include/amqpcpp/linux_tcp.h:2:0,
             from /usr/local/include/amqpcpp/libevent.h:23,
             from rabbitmq_handler.h:6,
             from main.cpp:1:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:30:30: error: expected class-name before ‘,’ token
     private ConnectionHandler,
                          ^
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:32:1: error: expected class-name before ‘{’ token
 {
 ^
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:39:10: error: ‘shared_ptr’ in namespace ‘std’ does not name a template type
     std::shared_ptr<TcpState> _state;
          ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:45:5: error: ‘Connection’ does not name a type; did you mean ‘TcpConnection’?
     Connection _connection;
     ^~~~~~~~~~
     TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:53:34: error: ‘Connection’ has not been declared
     virtual uint16_t onNegotiate(Connection *connection, uint16_t interval) override;
                                  ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:61:25: error: ‘Connection’ has not been declared
     virtual void onData(Connection *connection, const char *buffer, size_t size) override;
                         ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:67:30: error: ‘Connection’ has not been declared
     virtual void onHeartbeat(Connection *connection) override;
                              ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:74:26: error: ‘Connection’ has not been declared
     virtual void onError(Connection *connection, const char *message) override;
                          ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:80:30: error: ‘Connection’ has not been declared
     virtual void onConnected(Connection *connection) override;
                              ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:86:27: error: ‘Connection’ has not been declared
     virtual void onClosed(Connection *connection) override;
                           ^~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:92:26: error: ‘Buffer’ does not name a type
     uint64_t parse(const Buffer &buffer)
                          ^~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:112:46: error: ‘Address’ does not name a type
     TcpConnection(TcpHandler *handler, const Address &address);
                                              ^~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:53:22: error: ‘virtual uint16_t AMQP::TcpConnection::onNegotiate(int*, uint16_t)’ marked ‘override’, but does not override
     virtual uint16_t onNegotiate(Connection *connection, uint16_t interval) override;
                      ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:61:18: error: ‘virtual void AMQP::TcpConnection::onData(int*, const char*, size_t)’ marked ‘override’, but does not override
     virtual void onData(Connection *connection, const char *buffer, size_t size) override;
                  ^~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:67:18: error: ‘virtual void AMQP::TcpConnection::onHeartbeat(int*)’ marked ‘override’, but does not override
     virtual void onHeartbeat(Connection *connection) override;
                  ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:74:18: error: ‘virtual void AMQP::TcpConnection::onError(int*, const char*)’ marked ‘override’, but does not override
     virtual void onError(Connection *connection, const char *message) override;
                  ^~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:80:18: error: ‘virtual void AMQP::TcpConnection::onConnected(int*)’ marked ‘override’, but does not override
     virtual void onConnected(Connection *connection) override;
                  ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:86:18: error: ‘virtual void AMQP::TcpConnection::onClosed(int*)’ marked ‘override’, but does not override
     virtual void onClosed(Connection *connection) override;
                  ^~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘uint64_t AMQP::TcpConnection::parse(const int&)’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:95:16: error: ‘_connection’ was not declared in this scope
         return _connection.parse(buffer);
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:95:16: note: suggested alternative: ‘TcpConnection’
         return _connection.parse(buffer);
                ^~~~~~~~~~~
                TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘bool AMQP::TcpConnection::close()’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:154:16: error: ‘_connection’ was not declared in this scope
         return _connection.close();
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:154:16: note: suggested alternative: ‘TcpConnection’
         return _connection.close();
                ^~~~~~~~~~~
                TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘uint32_t AMQP::TcpConnection::maxFrame() const’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:163:16: error: ‘_connection’ was not declared in this scope
         return _connection.maxFrame();
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:163:16: note: suggested alternative: ‘TcpConnection’
         return _connection.maxFrame();
                ^~~~~~~~~~~
                TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘uint32_t AMQP::TcpConnection::expected() const’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:172:16: error: ‘_connection’ was not declared in this scope
         return _connection.expected();
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:172:16: note: suggested alternative: ‘TcpConnection’
         return _connection.expected();
                ^~~~~~~~~~~
                TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘std::size_t AMQP::TcpConnection::channels() const’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:182:16: error: ‘_connection’ was not declared in this scope
         return _connection.channels();
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:182:16: note: suggested alternative: ‘TcpConnection’
         return _connection.channels();
                ^~~~~~~~~~~
                TcpConnection
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h: In member function ‘bool AMQP::TcpConnection::heartbeat()’:
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:197:16: error: ‘_connection’ was not declared in this scope
         return _connection.heartbeat();
                ^~~~~~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpconnection.h:197:16: note: suggested alternative: ‘TcpConnection’
         return _connection.heartbeat();
                ^~~~~~~~~~~
                TcpConnection
In file included from /usr/local/include/amqpcpp/linux_tcp.h:3:0,
                 from /usr/local/include/amqpcpp/libevent.h:23,
                 from rabbitmq_handler.h:6,
                 from main.cpp:1:
/usr/local/include/amqpcpp/linux_tcp/tcpchannel.h: At global scope:
/usr/local/include/amqpcpp/linux_tcp/tcpchannel.h:24:1: error: expected class-name before ‘{’ token
 {
 ^
/usr/local/include/amqpcpp/linux_tcp/tcpchannel.h: In constructor ‘AMQP::TcpChannel::TcpChannel(AMQP::TcpConnection*)’:
/usr/local/include/amqpcpp/linux_tcp/tcpchannel.h:35:9: error: class ‘AMQP::TcpChannel’ does not have any field named ‘Channel’
         Channel(&connection->_connection) {}
         ^~~~~~~
/usr/local/include/amqpcpp/linux_tcp/tcpchannel.h:35:30: error: ‘class AMQP::TcpConnection’ has no member named ‘_connection’; did you mean ‘TcpConnection’?
         Channel(&connection->_connection) {}
                              ^~~~~~~~~~~
                              TcpConnection
In file included from rabbitmq_handler.h:6:0,
                 from main.cpp:1:
/usr/local/include/amqpcpp/libevent.h: At global scope:
/usr/local/include/amqpcpp/libevent.h:140:10: error: ‘map’ in namespace ‘std’ does not name a template type
     std::map<int,std::unique_ptr<Watcher>> _watchers;
          ^~~
/usr/local/include/amqpcpp/libevent.h: In member function ‘virtual void AMQP::LibEventHandler::monitor(AMQP::TcpConnection*, int, int)’:
/usr/local/include/amqpcpp/libevent.h:152:21: error: ‘_watchers’ was not declared in this scope
         auto iter = _watchers.find(fd);
                     ^~~~~~~~~
/usr/local/include/amqpcpp/libevent.h:152:21: note: suggested alternative: ‘Watcher’
         auto iter = _watchers.find(fd);
                     ^~~~~~~~~
                     Watcher
/usr/local/include/amqpcpp/libevent.h:161:34: error: ‘unique_ptr’ is not a member of ‘std’
             _watchers[fd] = std::unique_ptr<Watcher>(new Watcher(_evbase, connection, fd, flags));
                                  ^~~~~~~~~~
/usr/local/include/amqpcpp/libevent.h:161:52: error: expected primary-expression before ‘>’ token
             _watchers[fd] = std::unique_ptr<Watcher>(new Watcher(_evbase, connection, fd, flags));

The g++ version is 7.3.0, the system is ubuntu16.04, amqpcpp version is 3.1.0.

My code is as below, there are 3 files, rabbitmq_handler.h, rabbitmq_handler.cpp and main.cc.

rabbitmq_handler.h

#pragma once

#include <functional>
#include <unistd.h>
#include <event2/event.h>
#include <amqpcpp/libevent.h>
#include <amqpcpp/linux_tcp.h>

class LibEventHandlerMyError : public AMQP::LibEventHandler
{
public:
    LibEventHandlerMyError(struct event_base* evbase) : LibEventHandler(evbase), evbase_(evbase) {}
    void onError(AMQP::TcpConnection *connection, const char *message) override
    {
        event_base_loopbreak(evbase_);
    }
private:
    struct event_base* evbase_ {nullptr};
};


int init_rabbitmq_conn();

rabbitmq_handler.cpp

#include <iostream>
#include <amqpcpp.h>
#include "rabbitmq_handler.h"


int init_rabbitmq_conn()
{
    auto evbase = event_base_new();
    LibEventHandlerMyError hndl(evbase);

    AMQP::TcpConnection connection(&hndl, AMQP::Address("amqp://localhost:5672/"));
    AMQP::TcpChannel channel(&connection);
    channel.onError([&evbase](const char* message)
        {
            std::cout << "Channel error: " << message << std::endl;
            event_base_loopbreak(evbase);
        });
    channel.declareQueue("hello", AMQP::exclusive)
        .onSuccess
        (
            [&connection](const std::string &name,
                          uint32_t messagecount,
                          uint32_t consumercount)
            { 
                std::cout << "Queue: " << name << std::endl;
            } 
        )
        .onFinalize
        (    
            [&connection]()
            {
                std::cout << "Finalize." << std::endl;
                connection.close();
            }
        );
    channel.publish("", "hello", "Hello, world!");

    event_base_dispatch(evbase);
    event_base_free(evbase);

    return 0;
}

main.cpp

#include "rabbitmq_handler.h"

int main(){
    init_rabbitmq_conn();   
    return 0;
}

General rule if you are struggling is address the first error. The following errors may be because of the first one. The error is reported in /usr/local/include/amqpcpp/linux_tcp/tcpconnection.h. Yo need to look at this file to work out what has gone wrong. With include files often a mistake in a previous include file can cause an error reported in a following one. I do not see any errors in the files you have provided. I would guess it is in one of the "system" files <...>. It could be an environment issue where you do not have the correct defines on the compile line. You need to dig. — William J Bagshaw, Jun 15 '18 at 13:24
If you are struggling with include files giving error one tool to debug is to keep pre-processed files. Its a massive file with everything that the compiler sees once all #defs and includes have been resolved. — William J Bagshaw, Jun 15 '18 at 13:26

score 1 · Accepted Answer · answered Jun 15 '18 at 13:22

You violate the rule in the manual:

After building there are two relevant files to include when using the library.

+-----------+---------------+
|   File    | Include when? |
+-----------+---------------+
| amqpcpp.h |    Always     |
+-----------+---------------+

You must #include <amqpcpp.h> before any #include <amqpcpp/...> in your rabbitmq_handler.h.

score 0 · Answer 2 · answered Jun 15 '18 at 13:34

I don't think you have included a definition for the class ConnectionHandler found in AMQP-CPP/include/amqpcpp/connectionhandler.h**

Sometimes you are expected to include a single include file that itself includes all the include files you need. You need to find that file and include it, or keep adding missing include files until it compiles. Do you have an example? Which include files does it include? A big list or just one that includes everything else?

compile the c++ amqp-cpp demo program err, make err

2 Answers2