Ubuntu Manpage: imake - C preprocessor interface to the make utility

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 Window System used 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 typically used to indicate the directory in which
the imake template and configuration 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 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 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 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 convention make variables
are upper case.

The rules file (usually named Imake.rules in the configuration directory) 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 used imake extensively up through the X11R6.9 release, for both full builds within
       the source tree and external software.  X has since moved to GNU autoconf  and  automake  for  its  build
       system  in  X11R7.0 and later releases, but still maintains imake for building existing external software
       programs that have not yet converted.

       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 directory 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 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
       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
       symbols.

FILES

       Imakefile.c
              temporary input file for cpp

       /tmp/Imf.XXXXXX
              temporary Makefile for -s

       /tmp/IIf.XXXXXX
              temporary Imakefile if specified Imakefile uses # comments

       /usr/bin/cpp
              default C preprocessor

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 program.  E.g., ``/usr/local/cpp''.  By
            default, imake will use cc -E or /usr/bin/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

X Version 11                                      imake 1.0.10                                          IMAKE(1)