makedepend(1X)                                     makedepend(1X)



NAME
     makedepend - creates dependencies in makefiles

SYNOPSIS
     makedepend [-Dname=def] [-Dname] [-Iincludedir] [-fmakefile]
     [-oobjsuffix] [-sstring] [-wwidth]
     [--options--] file...

DESCRIPTION
     makedepend reads each file in sequence and parses it like a
     C-preprocessor, processing all #include, #define, #undef,
     #ifdef, #ifndef, #endif, #if, and #else directives so that
     it can correctly tell which #include directives would be
     used in a compilation.  Any #include directives can refer-
     ence files having other #include directives, and parsing oc-
     curs in these files as well.

     Every file that file includes, directly or indirectly, is
     what
     makedepend calls a dependency.  These dependencies are then
     written to a make(1) description file in such a way that
     make knows which object files must be recompiled when a
     dependency has changed.

     By default, makedepend places its output in a file named
     makefile if it exists; otherwise makedepend places its out-
     put in a file named Makefile.  You can specify an alternate
     makefile by using the -f option.  The makedepend command
     first searches for a string that is a delimiter for the
     dependency output. It searchs the makefile for the string

     # DO NOT DELETE THIS LINE -- make depend depends on it.

     or searches for a string specified by the -s option.  If the
     string is found, makedepend deletes everything following the
     string and places its output after the string.  If the
     string is not found,
     makedepend appends the string to the end of the makefile and
     places its output after the string.  For each file appearing
     on the command line, makedepend puts lines in the makefile
     of the form

        file.o: dfile ...

     where file.o is file from the command line with its suffix
     replaced with .o, and dfile is a dependency discovered in a
     #include directive while parsing file or one of the files it
     includes.

   Options
     The makedepend command accepts the same options as cc(1) and
     ignores any options that it does not understand.



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makedepend(1X)                                     makedepend(1X)



     -fmakefile
             Specifies an alternate makefile in which makedepend
             can place its output.

     -Iincludedir
             Specifies a directory to search for include files.
             This option tells makedepend to prepend includedir
             to its list of directories to search when it en-
             counters a #include directive.  By default, mak-
             edepend only searches /usr/include.

     -Dname

     -Dname=def

             Specifies a definition for name in the makedepend

             symbol table.  If you omit =def, the symbol is de-

             fined as 1.


     -oobjsuffix

             Specifies an alternate object-file suffix.  Some

             systems may have object files whose suffix is some-

             thing other than .o.


     -sstring

             Specifies a string delimiter for makedepend to look

             for in the makefile.


     -wwidth Specifies a line width.  For the sake of readabili-

             ty,

             makedepend ensures that every output line that it

             writes is no wider than 78 characters.  This option

             allows you to change the default width.


     - - options - -

             Specifies a series of options for makedepend to

             silently ignore.  The second double hyphen ter-

             minates the series.  In this way, makedepend can be

             made to safely ignore esoteric compiler arguments

             that might normally be found in a CFLAGS make macro.

             See ``Examples'' later in this manual page.  All

             makedepend options that occur between a pair of dou-

             ble hyphens are processed normally.


   Algorithm

     The performance of makedepend relies on two assumptions:

     first, all files compiled by a single makefile are compiled

     with roughly the same -I and -D options; and second, most

     files in a single directory generally include the same

     files.


     Given these assumptions, makedepend expects to be called

     once for each makefile, with all source files that are main-

     tained by the makefile appearing on the command line.  It



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makedepend(1X)                                     makedepend(1X)



     parses each source and include file exactly once, maintain-
     ing an internal symbol table for each.  Thus, the first file
     on the command line takes an amount of time proportional to
     the amount of time that a normal C preprocessor takes.  If
     on subsequent files an include file that has already been
     parsed is encountered, makedepend does not parse the include
     file again.

     For example, imagine you are compiling two files, file1.c
     and file2.c.  Both files include the header file header.h,
     and header.h includes the files def1.h and def2.h.  When you
     run the command

        makedepend file1.c file2.c

     makedepend parses file1.c and consequently, header.h and
     then def1.h and def2.h.  The result is the following depen-
     dency:

            file1.o: header.h def1.h def2.h

     When makedepend parses file2.c, it discovers that file2.c
     also includes header.h.  There is no need to parse header.h,
     so makedepend simply adds header.h, def1.h, and def2.h to
     the list of dependencies for file2.o.

EXAMPLES
     Normally, makedepend is used in a makefile target so that
     the command

        make depend

     updates the dependencies in a makefile.  For example,

        SRCS = file1.c file2.c ...
        CFLAGS = -O -DHACK -I../foobar -xyz
        depend:
             makedepend -- $(CFLAGS) -- $(SRCS)


LIMITATIONS
     The makedepend command is compiled in such a way that all
     #if directives evaluate to TRUE regardless of their actual
     value.  This action may cause the wrong #include directives
     to be evaluated.  The makedepend command should simply have
     its own parser written for #if directives.

     Imagine you are parsing two files, file1.c and file2.c.
     Each includes the file def.h. The list of files that def.h
     includes might truly be different when def.h is included by
     file1.c than when it is included by file2.c. But once mak-
     edepend arrives at a list of dependencies for a file, the



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makedepend(1X)                                     makedepend(1X)



     list cannot be changed.

NOTES
     Author: Todd Brunhoff, Tektronix, Inc. and MIT Project Athe-
     na

SEE ALSO
     cc(1), make(1) in A/UX Command Reference















































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