makedepend(1X)makedepend(1X)NAMEmakedepend - create dependencies in makefiles
SYNOPSISmakedepend [-Dname=def] [-Dname] [-Iincludedir] [-Yincludedir] [-a]
[-fmakefile] [-oobjsuffix] [-pobjprefix] [-sstring] [-wwidth] [-v] [-m]
[-- otheroptions --] sourcefile ...
OPTIONS
Makedepend will ignore any option that it does not understand so that
you may use the same arguments that you would for cc(1). Define. This
places a definition for name in makedepend's symbol table. Without =def
the symbol becomes defined as "1". 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). Replace all of the stan‐
dard include directories with the single specified include directory;
you can omit the includedir to simply prevent searching the standard
include directories. Append the dependencies to the end of the file
instead of replacing them. Filename. This allows you to specify an
alternate makefile in which makedepend can place its output. Object
file suffix. Some systems may have object files whose suffix is some‐
thing other than ".o". This option allows you to specify another suf‐
fix, such as ".b" with -o.b or ":obj" with -o:obj and so forth. Object
file prefix. The prefix is prepended to the name of the object file.
This is usually used to designate a different directory for the object
file. The default is the empty string. Starting string delimiter. This
option permits you to specify a different string for makedepend to look
for in the makefile. 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. Verbose operation. This option causes makedepend to emit the
list of files included by each input file on standard output. 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 com‐
piler, 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 multiple inclusion. If makedepend encounters a
double hyphen (--) in the argument list, then any unrecognized argument
following it will be silently ignored; a second double hyphen termi‐
nates this special treatment. In this way, makedepend can be made to
safely ignore esoteric compiler arguments that might normally be found
in a CFLAGS make macro (see the EXAMPLE section below). All options
that makedepend recognizes and appear between the pair of double
hyphens are processed normally.
DESCRIPTIONmakedepend reads each sourcefile in sequence and parses it like a C-
preprocessor, processing all #include, #define, #undef, #ifdef, #ifn‐
def, #endif, #if and #else directives so that it can correctly tell
which #include, directives would be used in a compilation. Any
#include, directives can reference files having other #include direc‐
tives, 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 makefile.
For example,
SRCS = file1.c file2.c ...
CFLAGS = -O -DHACK -I../foobar -xyz
depend:
makedepend-- $(CFLAGS) -- $(SRCS)
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 subse‐
quent files, if it encounter's 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 com‐
mand
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.
BUGSmakedepend 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
dependencies for a file, it is cast in concrete.
SEE ALSOcc(1), make(1)AUTHOR
Todd Brunhoff, Tektronix, Inc., and MIT Project Athena
makedepend(1X)
