Makefiles

• I have been using the make utility in class all along.
• It is a rule based system for compiling programs.
• It has a number of default rules for building c, fortran, c++ ... executables
• We can provide additional rules.
• We put these in a file called Makefile
  • Format is just a bit tricky, but not too bad for what we want to do.
  • add a single line

    all:: program1, program2, program3
    	

  • When you type make, it will build program1, program2 and program3 if it can and if it needs to.
  • In addition add a single line

    CPPFLAGS = -g
    	

  • All c++ programs will be compiled with the debugging information.

Debugger

• If you compile your program with a -g you can run the interactive debugger on it.
• For example to compile the program myprog.C

  g++ -o myprog -g myprog.C
  

• gdb executable
• For example, do debug the program myprog

  gdb myprog
  

• Some commands

  Command	Action
  l	list 10 lines of the program.
  l n	list 10 lines, near line n.
  b n	set a breakpoint at line n.
  b proc_name	break when procedure proc_name is called.
  r	run the program.
  p var	print the value of the variable var.
  s	step to the next instruction, going into procedures.
  n	step to the next line, but don't go into procedures.
  q	quit the program.