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.\"     @(#)mkdep.1	8.1 (Berkeley) 6/6/93
.\" $FreeBSD$
.\"
.Dd June 6, 1993
.Dt MKDEP 1
.Os
.Sh NAME
.Nm mkdep
.Nd construct Makefile dependency list
.Sh SYNOPSIS
.Nm
.Op Fl ap
.Op Fl f Ar file
.Op Ar flags
.Ar
.Sh DESCRIPTION
The
.Nm
utility takes a set of flags for the C compiler and a list
of C source files as arguments and constructs a set of include
file dependencies which are written into the file ``.depend''.
An example of its use in a Makefile might be:
.Bd -literal -offset indent
CFLAGS= -O -I../include
SRCS= file1.c file2.c

depend:
	mkdep ${CFLAGS} ${SRCS}
.Ed
.Pp
where the macro SRCS is the list of C source files and the macro
CFLAGS is the list of flags for the C compiler.
.Pp
The user has the ability to change the preprocessor and preprocessor options
used.
For instance, to use gcc as the preprocessor and to ignore system
headers, one would use
.Bd -literal -offset indent
depend:
	env MKDEP_CPP="gcc -E" MKDEP_CPP_OPTS=-MM mkdep \\
		${CFLAGS} ${SRCS}
.Ed
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl a
Append to the output file,
so that multiple
.Nm Ns 's
may be run from a single Makefile.
.It Fl f
Write the include file dependencies to
.Ar file ,
instead of the default ``.depend''.
.It Fl p
Cause
.Nm
to produce dependencies of the form:
.Bd -literal -offset indent
program: program.c
.Ed
.Pp
so that subsequent makes will produce
.Ar program
directly from its C module rather than using an intermediate
.Pa \&.o
module.
This is useful for programs whose source is contained in a single
module.
.El
.Sh ENVIRONMENT
.Bl -tag -width MKDEP_CPP_OPTS
.It Ev CC
Specifies the C compiler to use.
The specified compiler is expected to have
options consistent with the GNU C compiler.
.It Ev MKDEP_CPP
Specifies the preprocessor to use.
The default is "${CC} -E".
.It Ev MKDEP_CPP_OPTS
Specifies the non-CFLAGS options for the preprocessor.
The default is
"-M".
.El
.Sh FILES
.Bl -tag -width .depend -compact
.It Pa .depend
File containing list of dependencies.
.El
.Sh SEE ALSO
.Xr cc 1 ,
.Xr cpp 1 ,
.Xr make 1
.Sh HISTORY
The
.Nm
command appeared in
.Bx 4.3 Tahoe .