The
ccmakedep
program calls a C compiler to preprocess each
sourcefile,
and uses the output to construct
makefile
rules describing their dependencies.
These rules instruct
make(1)
on which object files must be recompiled when a dependency has changed.
By default,
ccmakedep
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 a line beginning with
# DO NOT DELETE
or one provided with the
-s
option, as a delimiter for the dependency output.
If it finds it, it will delete everything following this up 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 makefile
and place the output after that.
EXAMPLE
Normally,
ccmakedep
will be used in a makefile target so that typing 'make depend' will bring
the dependencies up to date for the makefile.
For example,
The program will ignore any option that it does not understand, so you may
use the same arguments that you would for
cc(1),
including
-D
and
-U
options to define and undefine symbols and
-I
to set the include path.
-a
Append the dependencies to the file instead of replacing existing
dependencies.
-cccompiler
Use this compiler to generate dependencies.
-fmakefile
Filename.
This allows you to specify an alternate makefile in which
ccmakedep
can place its output.
Specifying lq-rq as the file name (that is,
-f-)
sends the output to standard output instead of modifying an existing file.
-sstring
Starting string delimiter.
This option permits you to specify a different string for
ccmakedep
to look for in the makefile.
The default is lq# DO NOT DELETErq.
-v
Be verbose: display the C compiler command before running it.
-- options --
If
ccmakedep
encounters a double hyphen (--) in the argument list, then any
unrecognized arguments following it will be silently ignored.
A second double hyphen terminates this special treatment.
In this way,
ccmakedep
can be made to safely ignore esoteric compiler arguments that might
normally be found in a CFLAGS
make
macro (see the
EXAMPLE
section above).
-D,
-I,
and
-U
options appearing between the pair of double hyphens are still processed
normally.