Compiling with Multiple Files

• This material is in section 12.3
• Header files.
  • Guards

    • #ifndef SOMETHING
      #define SOMETHING
      
      c++ code here
      
      #endif
      

    • Prevents multiple definition of the objects
    • SOMETHING should not start with a _
  • Other things the "library" will provide to the outside world
    • Type definitions.
    • Constant definitions
    • function prototypes.
    • Any include files to define types needed for the above.
  • But not
    • Source code.
  • And possibly not
    • using namespace std;
• Implementation file
  • Include the header file in quotes, not angle brackets.

    #include "myheader.h"
    

  • implements everything promised in the header file.
  • Could have auxiliary routines not in the header file.
  • Compile with -c -o myfile.o flags
  • Or better in Makefile
• Files using the routines
  • Include the header files in quotes, not angle brackets.
  • Link with .o file produced above.
• An example:
  • Assume code has been decomposed into three files.
    • A set of files containing sorting routines, sort.h and sort.C
    • A set of files containing auxiliary routines, aux.h and aux.C
    • The main program main.C.
    • And the Makefile
• In the makefile, you describe this graph