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MAKEDEPEND(1)							 MAKEDEPEND(1)

NAME
       makedepend - create dependencies	in makefiles

SYNOPSIS
       makedepend  [ -Dname=def	] [ -Dname ] [ -Iincludedir ] [	-Yincludedir ]
       [ -a ] [	-fmakefile ] [ -include	file ] [ -oobjsuffix ] [ -pobjprefix ]
       [  -sstring  ] [	-wwidth	] [ -v ] [ -m ]	[ -- otheroptions -- ] source-
       file ...

DESCRIPTION
       The makedepend program reads each sourcefile in sequence	and parses  it
       like  a	C-preprocessor,	 processing  all  #include,  #define,  #undef,
       #ifdef, #ifndef,	#endif,	#if, #elif and #else directives	so that	it can
       correctly  tell	which #include,	directives would be used in a compila-
       tion.  Any  #include,  directives  can  reference  files	 having	 other
       #include	directives, and	parsing	will occur in these files as well.

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

       By default, makedepend places its output	in the file named makefile  if
       it  exists, otherwise Makefile.	An alternate makefile may be specified
       with the	-f option.  It first searches the makefile for the line

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

       or one provided with the	-s option, as a	delimiter for  the  dependency
       output.	 If  it	 finds it, it will delete everything following this to
       the end of the makefile and put the output  after  this	line.	If  it
       doesn't	find  it, the program will append the string to	the end	of the
       makefile	and place the output  following	 that.	 For  each  sourcefile
       appearing on the	command	line, makedepend puts lines in the makefile of
       the form

	    sourcefile.o: dfile	...

       Where sourcefile.o is the name from the command line  with  its	suffix
       replaced	 with  ``.o'',	and  dfile  is	a  dependency  discovered in a
       #include	directive while	parsing	sourcefile or  one  of	the  files  it
       included.

EXAMPLE
       Normally,  makedepend  will be used in a	makefile target	so that	typing
       ``make depend'' will bring the dependencies up to date  for  the	 make-
       file.  For example,
	   SRCS	= file1.c file2.c ...
	   CFLAGS = -O -DHACK -I../foobar -xyz
	   depend:
		   makedepend -- $(CFLAGS) -- $(SRCS)

OPTIONS
       The  program will ignore	any option that	it does	not understand so that
       you may use the same arguments that you would for cc(1).

       -Dname=def or -Dname
	    Define.  This places a definition for name in makedepend's	symbol
	    table.  Without =def the symbol becomes defined as ``1''.

       -Iincludedir
	    Include  directory.	  This	option	tells  makedepend  to  prepend
	    includedir to its list of directories to search when it encounters
	    a  #include	 directive.   By default, makedepend only searches the
	    standard include directories (usually /usr/include and possibly  a
	    compiler-dependent directory).

       -Yincludedir
	    Replace  all  of  the standard include directories with the	single
	    specified include directory; you can omit the includedir to	simply
	    prevent searching the standard include directories.

       -a   Append  the	dependencies to	the end	of the file instead of replac-
	    ing	them.

       -fmakefile
	    Filename.  This allows you to specify  an  alternate  makefile  in
	    which  makedepend  can  place its output.  Specifying ``-''	as the
	    file name (i.e., -f-) sends	the output to standard output  instead
	    of modifying an existing file.

       -include	file
	    Process file as input, and include all the resulting output	before
	    processing the regular input file. This has	the same affect	as  if
	    the	specified file is an include statement that appears before the
	    very first line of the regular input file.

       -oobjsuffix
	    Object file	suffix.	 Some systems may have object files whose suf-
	    fix	 is  something	other  than ``.o''.  This option allows	you to
	    specify another suffix, such as ``.b'' with	-o.b or	``:obj''  with
	    -o:obj and so forth.

       -pobjprefix
	    Object  file  prefix.   The	prefix is prepended to the name	of the
	    object file. This is usually used to designate a different	direc-
	    tory for the object	file.  The default is the empty	string.

       -sstring
	    Starting  string  delimiter.  This option permits you to specify a
	    different string for makedepend to look for	in the makefile.

       -wwidth
	    Line width.	 Normally, makedepend will ensure  that	 every	output
	    line  that	it  writes will	be no wider than 78 characters for the
	    sake of readability.  This	option	enables	 you  to  change  this
	    width.

       -v   Verbose operation.	This option causes makedepend to emit the list
	    of files included by each input file.

       -m   Warn about multiple	inclusion.  This option	causes	makedepend  to
	    produce  a	warning	 if  any input file includes another file more
	    than once.	In  previous  versions	of  makedepend	this  was  the
	    default behavior; the default has been changed to better match the
	    behavior of	the C  compiler,  which	 does  not  consider  multiple
	    inclusion  to  be  an error.  This option is provided for backward
	    compatibility, and to aid in debugging problems related to	multi-
	    ple	inclusion.

       -- options --
	    If	makedepend  encounters	a  double  hyphen (--) in the argument
	    list, then any unrecognized	argument following it will be silently
	    ignored; a second double hyphen terminates this special treatment.
	    In this way, makedepend can	be made	to safely ignore esoteric com-
	    piler  arguments  that  might  normally  be	found in a CFLAGS make
	    macro (see the EXAMPLE section above).  All	options	 that  makede-
	    pend  recognizes and appear	between	the pair of double hyphens are
	    processed normally.

ALGORITHM
       The approach used in this program enables it to run an order of	magni-
       tude  faster  than any other ``dependency generator'' I have ever seen.
       Central to this performance are two assumptions:	that  all  files  com-
       piled  by  a  single makefile will be compiled with roughly the same -I
       and -D options; and that	most files in a	single directory will  include
       largely the same	files.

       Given  these assumptions, makedepend expects to be called once for each
       makefile, with all source files that are	 maintained  by	 the  makefile
       appearing  on the command line.	It parses each source and include file
       exactly once, maintaining an internal symbol table for each.  Thus, the
       first file on the command line will take	an amount of time proportional
       to the amount of	time that a normal C preprocessor takes.  But on  sub-
       sequent	files,	if  it	encounters an include file that	it has already
       parsed, it does not parse it again.

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

	   makedepend file1.c file2.c

       makedepend will parse  file1.c  and  consequently,  header.h  and  then
       def1.h and def2.h.  It then decides that	the dependencies for this file
       are

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

       But when	the  program  parses  file2.c  and  discovers  that  it,  too,
       includes	 header.h,  it	does  not  parse  the  file,  but  simply adds
       header.h, def1.h	and def2.h to the list of dependencies for file2.o.

SEE ALSO
       cc(1), make(1)

BUGS
       makedepend parses, but does not currently evaluate,  the	 SVR4  #predi-
       cate(token-list)	 preprocessor  expression; such	expressions are	simply
       assumed to be true.  This may cause the wrong #include directives to be
       evaluated.

       Imagine	you  are  parsing  two	files,	say  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 makedepend arrives at a list  of	depen-
       dencies for a file, it is cast in concrete.

AUTHOR
       Todd Brunhoff, Tektronix, Inc. and MIT Project Athena

4th Berkeley Distribution	 Version 4.7.0			 MAKEDEPEND(1)

NAME | SYNOPSIS | DESCRIPTION | EXAMPLE | OPTIONS | ALGORITHM | SEE ALSO | BUGS | AUTHOR

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