IMAKE(1)
NAME
imake - C preprocessor interface to the make utility
SYNOPSIS
imake [ -Ddefine ] [ -Idir ] [ -Ttemplate ] [ -f filename
] [ -C filename ] [ -s filename ] [ -e ] [ -v ]
DESCRIPTION
Imake is used to generate Makefiles from a template, a set
of cpp macro functions, and a per-directory input file
called an Imakefile. This allows machine dependencies
(such as compiler options, alternate command names, and
special make rules) to be kept separate from the descrip-
tions of the various items to be built.
OPTIONS
The following command line options may be passed to imake:
-Ddefine
This option is passed directly to cpp. It is typ-
ically used to set directory-specific variables.
For example, the X Window System uses this flag to
set TOPDIR to the name of the directory containing
the top of the core distribution and CURDIR to the
name of the current directory, relative to the
top.
-Idirectory
This option is passed directly to cpp. It is typ-
ically used to indicate the directory in which the
imake template and configuration files may be
found.
-Ttemplate
This option specifies the name of the master tem-
plate file (which is usually located in the direc-
tory specified with -I) used by cpp. The default
is Imake.tmpl.
-f filename
This option specifies the name of the per-direc-
tory input file. The default is Imakefile.
-C filename
This option specifies the name of the .c file that
is constructed in the current directory. The
default is Imakefile.c.
-s filename
This option specifies the name of the make
description file to be generated but make should
not be invoked. If the filename is a dash (-),
the output is written to stdout. The default is
to generate, but not execute, a Makefile.
-e This option indicates the imake should execute the
generated Makefile. The default is to leave this
to the user.
-v This option indicates that imake should print the
cpp command line that it is using to generate the
Makefile.
HOW IT WORKS
Imake invokes cpp with any -I or -D flags passed on the
command line and passes the name of a file containing the
following 3 lines:
#define IMAKE_TEMPLATE "Imake.tmpl"
#define INCLUDE_IMAKEFILE <Imakefile>
#include IMAKE_TEMPLATE
where Imake.tmpl and Imakefile may be overridden by the -T
and -f command options, respectively.
The IMAKE_TEMPLATE typically reads in a file containing
machine-dependent parameters (specified as cpp symbols), a
site-specific parameters file, a file defining variables,
a file containing cpp macro functions for generating make
rules, and finally the Imakefile (specified by
INCLUDE_IMAKEFILE) in the current directory. The Imake-
file uses the macro functions to indicate what targets
should be built; imake takes care of generating the appro-
priate rules.
Imake configuration files contain two types of variables,
imake variables and make variables. The imake variables
are interpreted by cpp when imake is run. By convention
they are mixed case. The make variables are written into
the Makefile for later interpretation by make. By conven-
tion make variables are upper case.
The rules file (usually named Imake.rules in the configu-
ration directory) contains a variety of cpp macro func-
tions that are configured according to the current plat-
form. Imake replaces any occurrences of the string ``@@''
with a newline to allow macros that generate more than one
line of make rules. For example, the macro
#define program_target(program, objlist) @@\
program: objlist @@\
$(CC) -o $@ objlist $(LDFLAGS)
when called with program_target(foo, foo1.o foo2.o) will
expand to
foo: foo1.o foo2.o
$(CC) -o $@ foo1.o foo2.o $(LDFLAGS)
Imake also replaces any occurrences of the word ``XCOMM''
with the character ``#'' to permit placing comments in the
Makefile without causing ``invalid directive'' errors from
the preprocessor.
Some complex imake macros require generated make variables
local to each invocation of the macro, often because their
value depends on parameters passed to the macro. Such
variables can be created by using an imake variable of the
form XVARdefn, where n is a single digit. A unique make
variable will be substituted. Later occurrences of the
variable XVARusen will be replaced by the variable created
by the corresponding XVARdefn.
On systems whose cpp reduces multiple tabs and spaces to a
single space, imake attempts to put back any necessary
tabs (make is very picky about the difference between tabs
and spaces). For this reason, colons (:) in command lines
must be preceded by a backslash (\).
USE WITH THE X WINDOW SYSTEM
The X Window System uses imake extensively, for both full
builds within the source tree and external software. As
mentioned above, two special variables, TOPDIR and CURDIR,
are set to make referencing files using relative path
names easier. For example, the following command is gen-
erated automatically to build the Makefile in the direc-
tory lib/X/ (relative to the top of the sources):
% ../.././config/imake -I../.././config \
-DTOPDIR=../../. -DCURDIR=./lib/X
When building X programs outside the source tree, a spe-
cial symbol UseInstalled is defined and TOPDIR and CURDIR
are omitted. If the configuration files have been prop-
erly installed, the script xmkmf(1) may be used.
INPUT FILES
Here is a summary of the files read by imake as used by X.
The indentation shows what files include what other files.
Imake.tmpl generic variables
site.def site-specific, BeforeVendorCF defined
*.cf machine-specific
*Lib.rules shared library rules
site.def site-specific, AfterVendorCF defined
Imake.rules rules
Project.tmpl X-specific variables
*Lib.tmpl shared library variables
Imakefile
Library.tmpl library rules
Server.tmpl server rules
Threads.tmpl multi-threaded rules
Note that site.def gets included twice, once before the
*.cf file and once after. Although most site customiza-
tions should be specified after the *.cf file, some, such
as the choice of compiler, need to be specified before,
because other variable settings may depend on them.
The first time site.def is included, the variable
BeforeVendorCF is defined, and the second time, the vari-
able AfterVendorCF is defined. All code in site.def
should be inside an #ifdef for one of these symbols.
FILES
Imakefile.c temporary input file for cpp
/tmp/Imf.XXXXXX temporary Makefile for -s
/tmp/IIf.XXXXXX temporary Imakefile if spec-
ified Imakefile uses # comments
/lib/cpp default C preprocessor
SEE ALSO
make(1) xmkmf(1)
S. I. Feldman, Make -- A Program for Maintaining Computer
Programs
ENVIRONMENT VARIABLES
The following environment variables may be set, however
their use is not recommended as they introduce dependen-
cies that are not readily apparent when imake is run:
IMAKEINCLUDE
If defined, this specifies a ``-I'' include argument
to pass to the C preprocessor. E.g.,
``-I/usr/X11/config''.
IMAKECPP
If defined, this should be a valid path to a prepro-
cessor program. E.g., ``/usr/local/cpp''. By
default, imake will use /lib/cpp.
IMAKEMAKE
If defined, this should be a valid path to a make
program, such as ``/usr/local/make''. By default,
imake will use whatever make program is found using
execvp(3). This variable is only used if the ``-e''
option is specified.
AUTHOR
Todd Brunhoff, Tektronix and MIT Project Athena; Jim Ful-
ton, MIT X Consortium