the make utility helps us

compile
link
manage files in a directory
execute shell commands

the make utility

input is a file containing rules

the rules specify what to do
(and under what circumstances)

name the file containing the rules:
makefile or (preferred) Makefile

Format of a Makefile

target1:  list of dependencies
	command1
	command2
target2:  list of dependencies
	command3
	command4

Each command is preceded by a tab.

Sample Makefile

my_binary:  binary.o list.o stack.o
	g++ -o my_binary binary.o list.o stack.o

binary.o:  binary.cpp binary.h common.h
	g++ -c binary.cpp
list.o:  list.cpp list.h common.h
	g++ -c list.cpp
stack.o:  stack.cpp stack.h common.h
	g++ -c stack.cpp

clean:
	rm binary.o list.o stack.o
reallyclean:
	rm my_binary binary.o list.o stack.o

Defining macros (variables)

OBJ = binary.o list.o stack.o

my_binary:  $(OBJ)
	cc -o my_binary $(OBJ)

binary.o:  binary.cpp binary.h common.h
	g++ -c binary.cpp
list.o:  list.cpp list.h common.h
	g++ -c list.cpp
stack.o:  stack.cpp stack.h common.h
	g++ -c stack.cpp

clean:
	rm core $(OBJ)
reallyclean:
	rm my_binary core $(OBJ)

Other things that make does,
but we do not have time to discuss

defaults
predefined stuff

purify

helps find memory mismanagement

compile program for use with purify

   purify g++ -g one.cpp two.cpp

running instrumented program
reports errors encountered

purify on a small example

testObject.h

#ifndef TESTOBJECT_H
#define TESTOBJECT_H

using namespace std;

class testObject {
   public:
     testObject();   // constructor
     ~testObject();  // destructor
     void printObject();
   private:
     int * intptr;   // dynamically allocated
                     // integer, or array
     int   x;
};

#endif

testObject.cpp

#include <iostream>
#include "testObject.h"

using namespace std;

// constructor
testObject::testObject() {
   cout << "testObject constructor invoked" << endl;
   intptr = new int;
   *intptr = 65;
   x = 64;
}

// destructor
testObject::~testObject() {
   cout << "testObject destructor invoked" << endl;

   // code missing, which causes a memory leak:
   // delete intptr;
}

// print x and what intptr points to
void testObject::printObject() {
   cout << "*intptr is " << *intptr << endl;
   cout << "x is " << x << endl;
}

testpurify.cpp

#include 
#include "testObject.h"
using namespace std;

int main() {
   char temp;

   //  cause a memory leak
   cout << "memory leak test. Hit 'y' to continue:";
   cin >> temp;
   if ( temp == 'y' ) {
      testObject T1;
      T1.printObject();
   }

   return 0; 
}

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