general.m4

LINUX下的源码工具,可自己分析,或者直接装在系统上作为应用

# This file is part of Autoconf.                       -*- Autoconf -*-
# Parameterized macros.
# Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001, 2002
# Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
# 02111-1307, USA.

# As a special exception, the Free Software Foundation gives unlimited
# permission to copy, distribute and modify the configure scripts that
# are the output of Autoconf.  You need not follow the terms of the GNU
# General Public License when using or distributing such scripts, even
# though portions of the text of Autoconf appear in them.  The GNU
# General Public License (GPL) does govern all other use of the material
# that constitutes the Autoconf program.
#
# Certain portions of the Autoconf source text are designed to be copied
# (in certain cases, depending on the input) into the output of
# Autoconf.  We call these the "data" portions.  The rest of the Autoconf
# source text consists of comments plus executable code that decides which
# of the data portions to output in any given case.  We call these
# comments and executable code the "non-data" portions.  Autoconf never
# copies any of the non-data portions into its output.
#
# This special exception to the GPL applies to versions of Autoconf
# released by the Free Software Foundation.  When you make and
# distribute a modified version of Autoconf, you may extend this special
# exception to the GPL to apply to your modified version as well, *unless*
# your modified version has the potential to copy into its output some
# of the text that was the non-data portion of the version that you started
# with.  (In other words, unless your change moves or copies text from
# the non-data portions to the data portions.)  If your modification has
# such potential, you must delete any notice of this special exception
# to the GPL from your modified version.
#
# Written by David MacKenzie, with help from
# Franc,ois Pinard, Karl Berry, Richard Pixley, Ian Lance Taylor,
# Roland McGrath, Noah Friedman, david d zuhn, and many others.


## ---------------- ##
## The diversions.  ##
## ---------------- ##


# We heavily use m4's diversions both for the initializations and for
# required macros (see AC_REQUIRE), because in both cases we have to
# issue high in `configure' something which is discovered late.
#
# KILL is only used to suppress output.
#
# The layers of `configure'.  We let m4 undivert them by itself, when
# it reaches the end of `configure.ac'.
#
# - BINSH
#   #! /bin/sh
# - HEADER-REVISION
#   Sent by AC_REVISION
# - HEADER-COMMENT
#   Purpose of the script.
# - HEADER-COPYRIGHT
#   Copyright notice(s)
# - M4SH-INIT
#   Initialization of bottom layers.
#
# - DEFAULTS
#   early initializations (defaults)
# - PARSE_ARGS
#   initialization code, option handling loop.
#
# - HELP_BEGIN
#   Handling `configure --help'.
# - HELP_CANON
#   Help msg for AC_CANONICAL_*
# - HELP_ENABLE
#   Help msg from AC_ARG_ENABLE.
# - HELP_WITH
#   Help msg from AC_ARG_WITH.
# - HELP_VAR
#   Help msg from AC_ARG_VAR.
# - HELP_VAR_END
#   A small paragraph on the use of the variables.
# - HELP_END
#   Tail of the handling of --help.
#
# - VERSION_BEGIN
#   Head of the handling of --version.
# - VERSION_FSF
#   FSF copyright notice for --version.
# - VERSION_USER
#   User copyright notice for --version.
# - VERSION_END
#   Tail of the handling of --version.
#
# - INIT_PREPARE
#   Tail of initialization code.
#
# - BODY
#   the tests and output code
#


# _m4_divert(DIVERSION-NAME)
# --------------------------
# Convert a diversion name into its number.  Otherwise, return
# DIVERSION-NAME which is supposed to be an actual diversion number.
# Of course it would be nicer to use m4_case here, instead of zillions
# of little macros, but it then takes twice longer to run `autoconf'!
#
# From M4sugar:
#    -1. KILL
# 10000. GROW
#
# From M4sh:
#    0. BINSH
#    1. HEADER-REVISION
#    2. HEADER-COMMENT
#    3. HEADER-COPYRIGHT
#    4. M4SH-INIT
# 1000. BODY
m4_define([_m4_divert(DEFAULTS)],        10)
m4_define([_m4_divert(PARSE_ARGS)],      20)

m4_define([_m4_divert(HELP_BEGIN)],     100)
m4_define([_m4_divert(HELP_CANON)],     101)
m4_define([_m4_divert(HELP_ENABLE)],    102)
m4_define([_m4_divert(HELP_WITH)],      103)
m4_define([_m4_divert(HELP_VAR)],       104)
m4_define([_m4_divert(HELP_VAR_END)],   105)
m4_define([_m4_divert(HELP_END)],       106)

m4_define([_m4_divert(VERSION_BEGIN)],  200)
m4_define([_m4_divert(VERSION_FSF)],    201)
m4_define([_m4_divert(VERSION_USER)],   202)
m4_define([_m4_divert(VERSION_END)],    203)

m4_define([_m4_divert(INIT_PREPARE)],   300)



# AC_DIVERT_PUSH(DIVERSION-NAME)
# AC_DIVERT_POP
# ------------------------------
m4_copy([m4_divert_push],[AC_DIVERT_PUSH])
m4_copy([m4_divert_pop], [AC_DIVERT_POP])



## ------------------------------------ ##
## Defining/requiring Autoconf macros.  ##
## ------------------------------------ ##


# AC_DEFUN(NAME, EXPANSION)
# AC_DEFUN_ONCE(NAME, EXPANSION)
# AC_BEFORE(THIS-MACRO-NAME, CALLED-MACRO-NAME)
# AC_REQUIRE(STRING)
# AC_PROVIDE(MACRO-NAME)
# AC_PROVIDE_IFELSE(MACRO-NAME, IF-PROVIDED, IF-NOT-PROVIDED)
# -----------------------------------------------------------
m4_copy([m4_defun],       [AC_DEFUN])
m4_copy([m4_defun_once],  [AC_DEFUN_ONCE])
m4_copy([m4_before],      [AC_BEFORE])
m4_copy([m4_require],     [AC_REQUIRE])
m4_copy([m4_provide],     [AC_PROVIDE])
m4_copy([m4_provide_if],  [AC_PROVIDE_IFELSE])


# AC_OBSOLETE(THIS-MACRO-NAME, [SUGGESTION])
# ------------------------------------------
m4_define([AC_OBSOLETE],
[AC_DIAGNOSE([obsolete], [$1 is obsolete$2])])



## ----------------------------- ##
## Implementing Autoconf loops.  ##
## ----------------------------- ##


# AC_FOREACH(VARIABLE, LIST, EXPRESSION)
# --------------------------------------
#
# Compute EXPRESSION assigning to VARIABLE each value of the LIST.
# LIST is a /bin/sh list, i.e., it has the form ` item_1 item_2
# ... item_n ': white spaces are separators, and leading and trailing
# spaces are meaningless.
#
# This macro is robust to active symbols:
#    AC_FOREACH([Var], [ active
#    b	act\
#    ive  ], [-Var-])end
#    => -active--b--active-end
m4_define([AC_FOREACH],
[m4_foreach([$1], m4_split(m4_normalize([$2])), [$3])])




## ----------------------------------- ##
## Helping macros to display strings.  ##
## ----------------------------------- ##


# AC_HELP_STRING(LHS, RHS, [COLUMN])
# ----------------------------------
#
# Format an Autoconf macro's help string so that it looks pretty when
# the user executes "configure --help".  This macro takes three
# arguments, a "left hand side" (LHS), a "right hand side" (RHS), and
# the COLUMN which is a string of white spaces which leads to the
# the RHS column (default: 26 white spaces).
#
# The resulting string is suitable for use in other macros that require
# a help string (e.g. AC_ARG_WITH).
#
# Here is the sample string from the Autoconf manual (Node: External
# Software) which shows the proper spacing for help strings.
#
#    --with-readline         support fancy command line editing
#  ^ ^                       ^
#  | |                       |
#  | column 2                column 26
#  |
#  column 0
#
# A help string is made up of a "left hand side" (LHS) and a "right
# hand side" (RHS).  In the example above, the LHS is
# "--with-readline", while the RHS is "support fancy command line
# editing".
#
# If the LHS extends past column 24, then the LHS is terminated with a
# newline so that the RHS is on a line of its own beginning in column
# 26.
#
# Therefore, if the LHS were instead "--with-readline-blah-blah-blah",
# then the AC_HELP_STRING macro would expand into:
#
#
#    --with-readline-blah-blah-blah
#  ^ ^                       support fancy command line editing
#  | |                       ^
#  | column 2                |
#  column 0                  column 26
#
m4_define([AC_HELP_STRING],
[m4_pushdef([AC_Prefix], m4_default([$3], [                          ]))dnl
m4_pushdef([AC_Prefix_Format],
           [  %-]m4_eval(m4_len(AC_Prefix) - 3)[s ])dnl [  %-23s ]
m4_text_wrap([$2], AC_Prefix, m4_format(AC_Prefix_Format, [$1]))dnl
m4_popdef([AC_Prefix_Format])dnl
m4_popdef([AC_Prefix])dnl
])




## ---------------------------------------------- ##
## Information on the package being Autoconf'ed.  ##
## ---------------------------------------------- ##


# It is suggested that the macros in this section appear before
# AC_INIT in `configure.ac'.  Nevertheless, this is just stylistic,
# and from the implementation point of, AC_INIT *must* be expanded
# beforehand: it puts data in diversions which must appear before the
# data provided by the macros of this section.

# The solution is to require AC_INIT in each of these macros.  AC_INIT
# has the needed magic so that it can't be expanded twice.



# _AC_INIT_PACKAGE(PACKAGE-NAME, VERSION, BUG-REPORT, [TARNAME])
# --------------------------------------------------------------
m4_define([_AC_INIT_PACKAGE],
[AS_LITERAL_IF([$1], [], [m4_warn([syntax], [AC_INIT: not a literal: $1])])
AS_LITERAL_IF([$2], [],  [m4_warn([syntax], [AC_INIT: not a literal: $2])])
AS_LITERAL_IF([$3], [],  [m4_warn([syntax], [AC_INIT: not a literal: $3])])
m4_ifndef([AC_PACKAGE_NAME],
          [m4_define([AC_PACKAGE_NAME],     [$1])])
m4_ifndef([AC_PACKAGE_TARNAME],
          [m4_define([AC_PACKAGE_TARNAME],
                     m4_default([$4],
                                [m4_bpatsubst(m4_tolower(m4_bpatsubst([[[$1]]],
                                                                     [GNU ])),
                                 [[^_abcdefghijklmnopqrstuvwxyz0123456789]],
                                 [-])]))])
m4_ifndef([AC_PACKAGE_VERSION],
          [m4_define([AC_PACKAGE_VERSION],   [$2])])
m4_ifndef([AC_PACKAGE_STRING],
          [m4_define([AC_PACKAGE_STRING],    [$1 $2])])
m4_ifndef([AC_PACKAGE_BUGREPORT],
          [m4_define([AC_PACKAGE_BUGREPORT], [$3])])
])


# AC_COPYRIGHT(TEXT, [VERSION-DIVERSION = VERSION_USER])
# ------------------------------------------------------
# Append Copyright information in the top of `configure'.  TEXT is
# evaluated once, hence TEXT can use macros.  Note that we do not
# prepend `# ' but `@%:@ ', since m4 does not evaluate the comments.
# Had we used `# ', the Copyright sent in the beginning of `configure'
# would have not been evaluated.  Another solution, a bit fragile,
# would have be to use m4_quote to force an evaluation:
#
#     m4_bpatsubst(m4_quote($1), [^], [# ])
m4_define([AC_COPYRIGHT],
[m4_divert_text([HEADER-COPYRIGHT],
[m4_bpatsubst([
$1], [^], [@%:@ ])])dnl
m4_divert_text(m4_default([$2], [VERSION_USER]),
[
$1])dnl
])# AC_COPYRIGHT


# AC_REVISION(REVISION-INFO)
# --------------------------
# The second quote in the translit is just to cope with font-lock-mode
# which sees the opening of a string.
m4_define([AC_REVISION],
[m4_divert_text([HEADER-REVISION],
                [@%:@ From __file__ m4_translit([$1], [$""]).])dnl
])




## ---------------------------------------- ##
## Requirements over the Autoconf version.  ##
## ---------------------------------------- ##


# AU::AC_PREREQ(VERSION)
# ----------------------
# Update this `AC_PREREQ' statement to require the current version of
# Autoconf.  But fail if ever this autoupdate is too old.
#
# Note that `m4_defn([m4_PACKAGE_VERSION])' below are expanded before
# calling `AU_DEFUN', i.e., it is hard coded.  Otherwise it would be
# quite complex for autoupdate to import the value of
# `m4_PACKAGE_VERSION'.  We could `AU_DEFUN' `m4_PACKAGE_VERSION', but
# this would replace all its occurrences with the current version of
# Autoconf, which is certainly not what the user intended.
AU_DEFUN([AC_PREREQ],
[m4_version_prereq([$1])[]dnl
[AC_PREREQ(]]m4_defn([m4_PACKAGE_VERSION])[[)]])


# AC_PREREQ(VERSION)
# ------------------
# Complain and exit if the Autoconf version is less than VERSION.
m4_copy([m4_version_prereq], [AC_PREREQ])






## ---------------- ##
## Initialization.  ##
## ---------------- ##


# All the following macros are used by AC_INIT.  Ideally, they should
# be presented in the order in which they are output.  Please, help us
# sorting it, or at least, don't augment the entropy.


# _AC_INIT_NOTICE
# ---------------
m4_define([_AC_INIT_NOTICE],
[m4_divert_text([HEADER-COMMENT],
[@%:@ Guess values for system-dependent variables and create Makefiles.
@%:@ Generated by m4_PACKAGE_STRING[]dnl
m4_ifset([AC_PACKAGE_STRING], [ for AC_PACKAGE_STRING]).])

m4_ifset([AC_PACKAGE_BUGREPORT],
         [m4_divert_text([HEADER-COMMENT],
                         [@%:@
@%:@ Report bugs to <AC_PACKAGE_BUGREPORT>.])])
])


# _AC_INIT_COPYRIGHT
# ------------------
# We dump to VERSION_FSF to make sure we are inserted before the
# user copyrights, and after the setup of the --version handling.