Makefile is a configuration file for the program make, it contains instructions for compiling one or more programs)

Here is an example of C++ Makefile named progC. This program calls Cplex libraries

Makefile

# Example of makefile For a Cplex in C++
CFLAGS=-Wall -O
#CFLAGS=-Wall -g
CPPFLAGS=-DNDEBUG -DIL_STD
CXX=g++
OBJ=progC.o progC2.o
 
progC: $(OBJ)
	$(CXX) $(CFLAGS) -o progC $(OBJ)  -lm -lilocplex -lconcert -lcplex -lpthread
# ^ TAB obligatoire en début de ligne
#                                             ----- librairies pour CPLEX ----------
 
progC.o: progC.cpp
	$(CXX) $(CFLAGS) $(CPPFLAGS) -c progC.cpp
 
progC2.o: progC2.cpp
	$(CXX) $(CFLAGS) $(CPPFLAGS) -c progC2.cpp
 
clean:
	rm -f progC progC.o

hash character (#) indicates that the line is a comments line, and will not be executed.

CFLAGS=-Wall -O: The variable CFLAGS will be assigned the value -Wall -O. Later you can call this variable in your program with the following syntax : $(CFLAGS). In this case the variable CFLAG corresponds to Warning and optimization options for the compiler. The instruction CPPFLAGS=-DNDEBUG -DIL_STD,is another assigned variable containing other parameter for the C++ preprocessor. in this case, it indicates to the preprocessor to define NDEBUG and IL_STD. These definitions are necessary in order for CPLEX to compile.

CXX=g++, assign the g++ compiler. . OBJ=progC.o progC2.o, here we define the variable OBJ which will include progC.o and progC2.o

progC: $(OBJ)

      $(CXX) $(CFLAGS) -o progC $(OBJ)  -lm -lilocplex -lconcert -lcplex -lpthread

progC.o: progC.cpp

      $(CXX) $(CFLAGS) $(CPPFLAGS) -c progC.cpp 
      

progC2.o: progC2.cpp

      $(CXX) $(CFLAGS) $(CPPFLAGS) -c progC2.cpp
      

clean:

      rm -f progC progC.o
      
      
      
      

Source code file : progC.cpp

C++

#include "progC2.h"
 
int main(int argc, char **argv)
{
  int  n;
 
  if (argc < 2)
    {
      printf("Usage: ./progC n \n");
      exit(1);
    }
 
  n = atoi(argv[1]);
 
  Fibonacci(n);
  return(1);
}

Here is the c++ source code file called progC2.cpp

c++

#include "progC2.h"
/* Print the nth number of Fibonacci's suite where n is a user input */
 
void Fibonacci(int n)
{
  int count, t1=0, t2=1, display=0;
  printf("Fibonacci Series: %d - %d - ", t1, t2); /* Print the 2 first numbers */
  count=2;    /* count=2 because the 2 first numbers are already printed */
  while (count<n)
  {
      display=t1+t2;
      t1=t2;
      t2=display;
      ++count;
      printf("%d - ",display);
  }
  printf("\n");
}

Finally, here is the source code for the header file ,,.h <file make c++> #include <cstdio> #include <cstdlib> #include <cmath> void Fibonacci(int n); </file> a Makefile file is composed of rules that have the following syntax Target: dependencies command Avant chaque commande il y a un TAB (caractère de tabulation). To execute the Makefile file, you need to type make The standard output when executing make >make g++ -Wall -O -DNDEBUG -DIL_STD -c progC.cpp g++ -Wall -O -o progC progC.o progC2.o -lm -lilocplex -lconcert -lcplex -lpthread Here are the files that are called when typing the command make is called makefile makefile~ progC progC2.cpp progC2.cpp~ progC2.h progC2.h~ progC2.o progC.cpp progC.cpp~ progC.o This is how to execute the program >./progC 14 Fibonacci Series: 0 - 1 - 1 - 2 - 3 - 5 - 8 - 13 - 21 - 34 - 55 - 89 - 144 - 233 - This how you use make clean'' command (defined in Makefile)

   >make clean
   rm -f progC progC.o