cflow(1)                                                 cflow(1)



NAME
     cflow - generates a C flowgraph

SYNOPSIS
     cflow [-dnum] [-i_] [-ix] [-r] file...

ARGUMENTS
     -dnum
          Specifies the depth (num) at which the flowgraph is cut
          off.  By default this is a very large number.  Any
          attempts to set the cutoff depth to a nonpositive
          integer will be met with contempt.

     file Specifies the file to be analyzed.

     -i_  Includes names that begin with an underscore.  The
          default is to exclude these functions (and data if -ix
          is used).

     -ix  Includes external and static data symbols.  The default
          is to include only functions in the flowgraph.

     -r   Reverses the caller:callee relationship producing an
          inverted listing showing the callers of each function.
          The listing is also sorted in lexicographical order by
          callee.

DESCRIPTION
     cflow analyzes a collection of C, yacc, lex, assembler, and
     object files and attempts to build a graph charting the
     external references.  Files suffixed in .y, .l, .c, and .i
     are yacc'd, lex'd, and C-preprocessed (bypassed for .i
     files) as appropriate and then run through the first pass of
     lint(1).  (The -I, -D, and -U options of the C-preprocessor
     are also understood.)  Files suffixed with .s are assembled
     and information is extracted (as in .o files) from the
     symbol table.  The output is collected and turned into a
     graph of external references, which is displayed upon the
     standard output.

     Each line of output begins with a reference (i.e., line)
     number, followed by a suitable number of tabs indicating the
     level.  Then the name of the global (normally only a
     function not defined as an external or beginning with an
     underscore; see below for the -i inclusion option), a colon,
     and its definition.  For information extracted from C
     source, the definition consists of an abstract type
     declaration (e.g., char *), and, delimited by angle
     brackets, the name of the source file and the line number
     where the definition was found.  Definitions extracted from
     object files indicate the filename and location counter
     under which the symbol appeared (e.g., text).  Leading



January 1992                                                    1

cflow(1)                                                 cflow(1)



     underscores in C-style external names are deleted.

     Once a definition of a name has been printed, subsequent
     references to that name contain only the reference number of
     the line where the definition may be found.  For undefined
     references, only <> is printed.

     When the nesting level becomes too deep, the -e option of
     pr(1) can be used to compress the tab expansion to something
     less than every eight spaces.

EXAMPLES
     Given the following in file.c:

        int  i;

        main()
        {
             f();
             g();
             f();
        }

        f()
        {
             i = h();
        }

     the command:

        cflow -ix file.c

     produces the output:

        1    main: int(), <file.c 4>
        2         f: int(), <file.c 11>
        3              h: <>
        4              i:int, <file.c 1>
        5         g: <>


STATUS MESSAGES AND VALUES
     Complains about bad options.  Complains about multiple
     definitions and only believes the first.  Other messages may
     come from the various programs used (such as the C-
     preprocessor).

LIMITATIONS
     Files produced by lex(1) and yacc(1) cause the reordering of
     line number declarations, which can confuse cflow.  To get
     proper results, feed cflow the yacc or lex input.




2                                                    January 1992

cflow(1)                                                 cflow(1)



FILES
     /usr/bin/cflow
          Executable file
     /usr/lib/lpfx
          File that filters line(1) output into dag input
     /usr/lib/nmf
          File that converts nm output into dag input
     /usr/lib/dag
          File containing a graph maker
     /usr/lib/flip
          File containing a reverser

SEE ALSO
     as(1), cc(1), cpp(1), lex(1), lint(1), nm(1), pr(1), yacc(1)









































January 1992                                                    3