post  Compiling multiple cpp files (abstract factory pattern).

satyr (2)   Link to this post
Hi,

I have been working with java for awhile and because of my school projects I needed to switch C++. I tried to implement some patterns in C++ but unfortunately I couldn't. Specifically, I tried to implement abstract factory pattern but since I used separated files (habitual behavior from java:)) I got errors in compilation. Could you give me some tips about the compilation and modeling(if I should use .h files instead of .cpp files or not) of my code?

Here is my code:

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//run.cpp
#include <iostream>

using namespace std;

int main(){
        HFact* fact;
#ifdef LINUX
        HFact* fact = new HelloLinFact;
#elif WINDOWS
        //HFact* fact = new HelloWinFact;
        cout<<"At the moment this implementation is not valid..."<<endl;
#endif

        CHello* hello = fact->getHelloNormal();
        hello->say();
        hello = fact->getHelloReversed();
        hello->say();
        hello = fact->getHelloWorld();
        hello->say();

        return 0;

}

//HFact.cpp
class HFact {
        public:
                extern virtual CHello* sayHelloNormal() = 0;
                extern virtual CHello* sayHelloRev() = 0;
                extern virtual CHello* sayHelloWorld() = 0;
};

//CHello.cpp
class CHello{
        public:
                virtual void say() = 0;
};

//HelloLinFact.cpp
class HelloLinFact : public HFact {
        public:
                CHello* getHelloNormal() {
                        return new HelloLinNormal;
                }

                CHello* getHelloReversed(){
                        return new HelloLinReversed;
                }

                CHello* getHelloWorld(){
                        return new HelloLinWorld;
                }
};

//HelloLinNormal.cpp
#include <iostream>

class HelloLinNormal : public CHello(){
        public:
                void say(){
                        cout>>"HelloNormal class says: Hello!";
                }
}

//HelloLinReversed.cpp
#include <iostream>

class HelloLinReversed : public CHello{
        public:
                void say(){
                        cout<<"HelloLinReversed says: olleH";
                }
}

//HelloLinWorld.cpp
#include <iostream>

class HelloLinWorld : CHello{
        public:
                void say(){
                        cout<<"HelloLinWorld says: Hello World!";
                }
}


I put all the classes in separate .cpp files. I will appreciate if you give me the compilation instructions for this code (I think I should link the object files to each other with gcc's -LObjName command but I couldn't do it). Additionally, any advice (putting classes to headers etc.) about the model is welcome.

Thanks for your helps in advance.

Duoas (3497)   Link to this post
The main file should follow this pattern:
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#include <standard-stuff>
...

#include "project-stuff.hpp"
...

void stuff_only_main_uses() ...
...

int main() {
  ...
  }


Include files typically follow this pattern:
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#ifndef MY_INCLUDE_HPP
#define MY_INCLUDE_HPP

#include <standard-stuff-needed-by-the-interface>
...

#include "project-stuff-needed-by-the-interface.hpp"
...

namespace my_include_hpp
  {

  class interface-class-definitions ...
  void interface-function-prototype-definitions ...
  extern const int interface-constant-definitions ...
  ...

  }

#endif


And finally, module files typically follow this format:
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#include <standard-stuff-needed-by-this-module-but-not-in-the-include-file>
...

#include "project-stuff-needed-by-this-module-but-not-in-the-include-file.hpp"
...

#include "my-include.hpp"

namespace my_include_hpp
  {

  // functions, etc. that are unique to this module
  // (wrap it in a namespace to avoid linker name collisions with other libraries)

  // definitions for everything declared in the hpp file

  }


Finally, to compile everything together, there are several options. But in one shot it is:

gcc -Wall -pedantic -o my-prog my-prog.cpp my-module1.cpp my-module2.cpp [ -llibrary1 ...]

If you use the standard math routines you'll have to link with the math library:
-lm

If you use other specialty libraries you'll have to link with them also. For example, using the PDCurses on Windows:
-lpdcurses

Hope this helps.
Last edited on
satyr (2)   Link to this post
Thanks for the response Duoas. Great tips.
Duoas (3497)   Link to this post
I'm glad that helped. :-)
Last edited on

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