imake
IMAKE(1) IMAKE(1)
NAME
imake - C preprocessor interface to the make utility
SYNOPSIS
imake [ -Ddefine ] [ -Idir ] [ -Udefine ] [ -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
descriptions 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 typically used
to set directory-specific variables. For example, the X Win-
dow System uses this flag to set TOPDIR to the name of the
directory containing the top of the core distribution and CUR-
DIR to the name of the current directory, relative to the top.
-Idirectory
This option is passed directly to cpp. It is typically used
to indicate the directory in which the imake template and con-
figuration files may be found.
-Udefine
This option is passed directly to cpp. It is typically used
to unset variables when debugging imake configuration files.
-Ttemplate
This option specifies the name of the master template file
(which is usually located in the directory specified with -I)
used by cpp. The default is Imake.tmpl.
-f filename
This option specifies the name of the per-directory input
file. The default is Imakefile.
-C filename
This option specifies the name of the .c file that is con-
structed in the current directory. The default is Imake-
file.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 com-
mand options, respectively.
The IMAKE_TEMPLATE typically reads in a file containing machine-depen-
dent 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 Imakefile uses the
macro functions to indicate what targets should be built; imake takes
care of generating the appropriate rules.
Imake configuration files contain two types of variables, imake vari-
ables and make variables. The imake variables are interpreted by cpp
when imake is run. By convention they are mixed case. The make vari-
ables are written into the Makefile for later interpretation by make.
By convention make variables are upper case.
The rules file (usually named Imake.rules in the configuration direc-
tory) contains a variety of cpp macro functions that are configured
according to the current platform. 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 generated 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 special symbol
UseInstalled is defined and TOPDIR and CURDIR are omitted. If the
configuration files have been properly 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 inden-
tation 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 customizations 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 variable AfterVendorCF is defined.
All code in site.def should be inside an #ifdef for one of these sym-
bols.
FILES
Imakefile.c temporary input file for cpp
/tmp/Imf.XXXXXX temporary Makefile for -s
/tmp/IIf.XXXXXX temporary Imakefile if specified Imake-
file uses # comments
"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 dependencies 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 preprocessor pro-
gram. E.g., ‘‘/usr/local/cpp’’. By default, imake will use cc
-E or "cpp", depending on the OS specific configuration.
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 Fulton, MIT X
Consortium
IMAKE(1)
