imake

IMAKE(1)                    General Commands Manual                   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  com-
       mand  names,  and  special make rules) to be kept separate from the de-
       scriptions 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  direc-
               tory  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 configu-
               ration 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 construc-
               ted 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 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 IN-
       CLUDE_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 ac-
       cording 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 pa-
       rameters 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 cor-
       responding 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 re-
       lease, for both full builds within the source tree and  external  soft-
       ware.   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 con-
       verted.

       As mentioned above, two special variables, TOPDIR and CURDIR,  are  set
       to  make referencing files using relative path names easier.  For exam-
       ple, 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 Use-
       Installed is defined and TOPDIR and CURDIR are omitted.  If the config-
       uration  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  af-
       ter  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 de-
       fined, 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

SEE ALSO
       make(1), xmkmf(1)

       Paul DuBois
              imake-Related        Software         and         Documentation,
              http://www.snake.net/software/imake-stuff/

       Paul DuBois
              Software  Portability with imake, Second Edition, O'Reilly & As-
              sociates, 1996.

       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 ap-
       parent 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 Con-
       sortium

X Version 11                      imake 1.0.7                         IMAKE(1)