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Diffstat (limited to 'gnuwin32/share/bison/m4sugar/m4sugar.m4')
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diff --git a/gnuwin32/share/bison/m4sugar/m4sugar.m4 b/gnuwin32/share/bison/m4sugar/m4sugar.m4 deleted file mode 100644 index 6fbd3431..00000000 --- a/gnuwin32/share/bison/m4sugar/m4sugar.m4 +++ /dev/null @@ -1,2789 +0,0 @@ -divert(-1)# -*- Autoconf -*- -# This file is part of Autoconf. -# Base M4 layer. -# Requires GNU M4. -# -# Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, -# 2008 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 3 of the License, 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, see <http://www.gnu.org/licenses/>. - -# 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 Akim Demaille. -# - -# Set the quotes, whatever the current quoting system. -changequote() -changequote([, ]) - -# Some old m4's don't support m4exit. But they provide -# equivalent functionality by core dumping because of the -# long macros we define. -ifdef([__gnu__], , -[errprint(M4sugar requires GNU M4. Install it before installing M4sugar or -set the M4 environment variable to its absolute file name.) -m4exit(2)]) - - -## ------------------------------- ## -## 1. Simulate --prefix-builtins. ## -## ------------------------------- ## - -# m4_define -# m4_defn -# m4_undefine -define([m4_define], defn([define])) -define([m4_defn], defn([defn])) -define([m4_undefine], defn([undefine])) - -m4_undefine([define]) -m4_undefine([defn]) -m4_undefine([undefine]) - - -# m4_copy(SRC, DST) -# ----------------- -# Define DST as the definition of SRC. -# What's the difference between: -# 1. m4_copy([from], [to]) -# 2. m4_define([to], [from($@)]) -# Well, obviously 1 is more expensive in space. Maybe 2 is more expensive -# in time, but because of the space cost of 1, it's not that obvious. -# Nevertheless, one huge difference is the handling of `$0'. If `from' -# uses `$0', then with 1, `to''s `$0' is `to', while it is `from' in 2. -# The user would certainly prefer to see `to'. -m4_define([m4_copy], -[m4_define([$2], m4_defn([$1]))]) - - -# m4_rename(SRC, DST) -# ------------------- -# Rename the macro SRC to DST. -m4_define([m4_rename], -[m4_copy([$1], [$2])m4_undefine([$1])]) - - -# m4_rename_m4(MACRO-NAME) -# ------------------------ -# Rename MACRO-NAME to m4_MACRO-NAME. -m4_define([m4_rename_m4], -[m4_rename([$1], [m4_$1])]) - - -# m4_copy_unm4(m4_MACRO-NAME) -# --------------------------- -# Copy m4_MACRO-NAME to MACRO-NAME. -m4_define([m4_copy_unm4], -[m4_copy([$1], m4_bpatsubst([$1], [^m4_\(.*\)], [[\1]]))]) - - -# Some m4 internals have names colliding with tokens we might use. -# Rename them a` la `m4 --prefix-builtins'. Conditionals first, since -# some subsequent renames are conditional. -m4_rename_m4([ifdef]) -m4_rename([ifelse], [m4_if]) - -m4_rename_m4([builtin]) -m4_rename_m4([changecom]) -m4_rename_m4([changequote]) -m4_ifdef([changeword],dnl conditionally available in 1.4.x -[m4_undefine([changeword])]) -m4_rename_m4([debugfile]) -m4_rename_m4([debugmode]) -m4_rename_m4([decr]) -m4_undefine([divert]) -m4_rename_m4([divnum]) -m4_rename_m4([dumpdef]) -m4_rename_m4([errprint]) -m4_rename_m4([esyscmd]) -m4_rename_m4([eval]) -m4_rename_m4([format]) -m4_undefine([include]) -m4_rename_m4([incr]) -m4_rename_m4([index]) -m4_rename_m4([indir]) -m4_rename_m4([len]) -m4_rename([m4exit], [m4_exit]) -m4_undefine([m4wrap]) -m4_ifdef([mkstemp],dnl added in M4 1.4.8 -[m4_rename_m4([mkstemp]) -m4_copy([m4_mkstemp], [m4_maketemp]) -m4_undefine([maketemp])], -[m4_rename_m4([maketemp]) -m4_copy([m4_maketemp], [m4_mkstemp])]) -m4_rename([patsubst], [m4_bpatsubst]) -m4_rename_m4([popdef]) -m4_rename_m4([pushdef]) -m4_rename([regexp], [m4_bregexp]) -m4_rename_m4([shift]) -m4_undefine([sinclude]) -m4_rename_m4([substr]) -m4_ifdef([symbols],dnl present only in alpha-quality 1.4o -[m4_rename_m4([symbols])]) -m4_rename_m4([syscmd]) -m4_rename_m4([sysval]) -m4_rename_m4([traceoff]) -m4_rename_m4([traceon]) -m4_rename_m4([translit]) -m4_undefine([undivert]) - - -## ------------------- ## -## 2. Error messages. ## -## ------------------- ## - - -# m4_location -# ----------- -m4_define([m4_location], -[__file__:__line__]) - - -# m4_errprintn(MSG) -# ----------------- -# Same as `errprint', but with the missing end of line. -m4_define([m4_errprintn], -[m4_errprint([$1 -])]) - - -# m4_warning(MSG) -# --------------- -# Warn the user. -m4_define([m4_warning], -[m4_errprintn(m4_location[: warning: $1])]) - - -# m4_fatal(MSG, [EXIT-STATUS]) -# ---------------------------- -# Fatal the user. :) -m4_define([m4_fatal], -[m4_errprintn(m4_location[: error: $1])dnl -m4_expansion_stack_dump()dnl -m4_exit(m4_if([$2],, 1, [$2]))]) - - -# m4_assert(EXPRESSION, [EXIT-STATUS = 1]) -# ---------------------------------------- -# This macro ensures that EXPRESSION evaluates to true, and exits if -# EXPRESSION evaluates to false. -m4_define([m4_assert], -[m4_if(m4_eval([$1]), 0, - [m4_fatal([assert failed: $1], [$2])])]) - - - -## ------------- ## -## 3. Warnings. ## -## ------------- ## - - -# _m4_warn(CATEGORY, MESSAGE, STACK-TRACE) -# ---------------------------------------- -# Report a MESSAGE to the user if the CATEGORY of warnings is enabled. -# This is for traces only. -# The STACK-TRACE is a \n-separated list of "LOCATION: MESSAGE". -# -# Within m4, the macro is a no-op. This macro really matters -# when autom4te post-processes the trace output. -m4_define([_m4_warn], []) - - -# m4_warn(CATEGORY, MESSAGE) -# -------------------------- -# Report a MESSAGE to the user if the CATEGORY of warnings is enabled. -m4_define([m4_warn], -[_m4_warn([$1], [$2], -m4_ifdef([m4_expansion_stack], - [_m4_defn([m4_expansion_stack]) -m4_location[: the top level]]))dnl -]) - - - -## ------------------- ## -## 4. File inclusion. ## -## ------------------- ## - - -# We also want to neutralize include (and sinclude for symmetry), -# but we want to extend them slightly: warn when a file is included -# several times. This is, in general, a dangerous operation, because -# too many people forget to quote the first argument of m4_define. -# -# For instance in the following case: -# m4_define(foo, [bar]) -# then a second reading will turn into -# m4_define(bar, [bar]) -# which is certainly not what was meant. - -# m4_include_unique(FILE) -# ----------------------- -# Declare that the FILE was loading; and warn if it has already -# been included. -m4_define([m4_include_unique], -[m4_ifdef([m4_include($1)], - [m4_warn([syntax], [file `$1' included several times])])dnl -m4_define([m4_include($1)])]) - - -# m4_include(FILE) -# ---------------- -# Like the builtin include, but warns against multiple inclusions. -m4_define([m4_include], -[m4_include_unique([$1])dnl -m4_builtin([include], [$1])]) - - -# m4_sinclude(FILE) -# ----------------- -# Like the builtin sinclude, but warns against multiple inclusions. -m4_define([m4_sinclude], -[m4_include_unique([$1])dnl -m4_builtin([sinclude], [$1])]) - - - -## ------------------------------------ ## -## 5. Additional branching constructs. ## -## ------------------------------------ ## - -# Both `m4_ifval' and `m4_ifset' tests against the empty string. The -# difference is that `m4_ifset' is specialized on macros. -# -# In case of arguments of macros, eg. $1, it makes little difference. -# In the case of a macro `FOO', you don't want to check `m4_ifval(FOO, -# TRUE)', because if `FOO' expands with commas, there is a shifting of -# the arguments. So you want to run `m4_ifval([FOO])', but then you just -# compare the *string* `FOO' against `', which, of course fails. -# -# So you want the variation `m4_ifset' that expects a macro name as $1. -# If this macro is both defined and defined to a non empty value, then -# it runs TRUE, etc. - - -# m4_ifval(COND, [IF-TRUE], [IF-FALSE]) -# ------------------------------------- -# If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE. -# Comparable to m4_ifdef. -m4_define([m4_ifval], -[m4_if([$1], [], [$3], [$2])]) - - -# m4_n(TEXT) -# ---------- -# If TEXT is not empty, return TEXT and a new line, otherwise nothing. -m4_define([m4_n], -[m4_if([$1], - [], [], - [$1 -])]) - - -# m4_ifvaln(COND, [IF-TRUE], [IF-FALSE]) -# -------------------------------------- -# Same as `m4_ifval', but add an extra newline to IF-TRUE or IF-FALSE -# unless that argument is empty. -m4_define([m4_ifvaln], -[m4_if([$1], - [], [m4_n([$3])], - [m4_n([$2])])]) - - -# m4_ifset(MACRO, [IF-TRUE], [IF-FALSE]) -# -------------------------------------- -# If MACRO has no definition, or of its definition is the empty string, -# expand IF-FALSE, otherwise IF-TRUE. -m4_define([m4_ifset], -[m4_ifdef([$1], - [m4_ifval(_m4_defn([$1]), [$2], [$3])], - [$3])]) - - -# m4_ifndef(NAME, [IF-NOT-DEFINED], [IF-DEFINED]) -# ----------------------------------------------- -m4_define([m4_ifndef], -[m4_ifdef([$1], [$3], [$2])]) - - -# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT) -# ----------------------------------------------------------- -# m4 equivalent of -# switch (SWITCH) -# { -# case VAL1: -# IF-VAL1; -# break; -# case VAL2: -# IF-VAL2; -# break; -# ... -# default: -# DEFAULT; -# break; -# }. -# All the values are optional, and the macro is robust to active -# symbols properly quoted. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_case], -[m4_if([$#], 0, [], - [$#], 1, [], - [$#], 2, [$2], - [$1], [$2], [$3], - [$0([$1], m4_shift3($@))])]) - - -# m4_bmatch(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT) -# ----------------------------------------------------- -# m4 equivalent of -# -# if (SWITCH =~ RE1) -# VAL1; -# elif (SWITCH =~ RE2) -# VAL2; -# elif ... -# ... -# else -# DEFAULT -# -# All the values are optional, and the macro is robust to active symbols -# properly quoted. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_bmatch], -[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])], - [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])], - [$#], 2, [$2], - [m4_if(m4_bregexp([$1], [$2]), -1, [$0([$1], m4_shift3($@))], - [$3])])]) - - -# m4_car(LIST) -# m4_cdr(LIST) -# ------------ -# Manipulate m4 lists. -m4_define([m4_car], [[$1]]) -m4_define([m4_cdr], -[m4_if([$#], 0, [m4_fatal([$0: cannot be called without arguments])], - [$#], 1, [], - [m4_dquote(m4_shift($@))])]) - -# _m4_cdr(LIST) -# ------------- -# Like m4_cdr, except include a leading comma unless only one element -# remains. Why? Because comparing a large list against [] is more -# expensive in expansion time than comparing the number of arguments; so -# _m4_cdr can be used to reduce the number of arguments when it is time -# to end recursion. -m4_define([_m4_cdr], -[m4_if([$#], 1, [], - [, m4_dquote(m4_shift($@))])]) - - - -# m4_cond(TEST1, VAL1, IF-VAL1, TEST2, VAL2, IF-VAL2, ..., [DEFAULT]) -# ------------------------------------------------------------------- -# Similar to m4_if, except that each TEST is expanded when encountered. -# If the expansion of TESTn matches the string VALn, the result is IF-VALn. -# The result is DEFAULT if no tests passed. This macro allows -# short-circuiting of expensive tests, where it pays to arrange quick -# filter tests to run first. -# -# For an example, consider a previous implementation of _AS_QUOTE_IFELSE: -# -# m4_if(m4_index([$1], [\]), [-1], [$2], -# m4_eval(m4_index([$1], [\\]) >= 0), [1], [$2], -# m4_eval(m4_index([$1], [\$]) >= 0), [1], [$2], -# m4_eval(m4_index([$1], [\`]) >= 0), [1], [$3], -# m4_eval(m4_index([$1], [\"]) >= 0), [1], [$3], -# [$2]) -# -# Here, m4_index is computed 5 times, and m4_eval 4, even if $1 contains -# no backslash. It is more efficient to do: -# -# m4_cond([m4_index([$1], [\])], [-1], [$2], -# [m4_eval(m4_index([$1], [\\]) >= 0)], [1], [$2], -# [m4_eval(m4_index([$1], [\$]) >= 0)], [1], [$2], -# [m4_eval(m4_index([$1], [\`]) >= 0)], [1], [$3], -# [m4_eval(m4_index([$1], [\"]) >= 0)], [1], [$3], -# [$2]) -# -# In the common case of $1 with no backslash, only one m4_index expansion -# occurs, and m4_eval is avoided altogether. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_cond], -[m4_if([$#], [0], [m4_fatal([$0: cannot be called without arguments])], - [$#], [1], [$1], - m4_eval([$# % 3]), [2], [m4_fatal([$0: missing an argument])], - [_$0($@)])]) - -m4_define([_m4_cond], -[m4_if(($1), [($2)], [$3], - [$#], [3], [], - [$#], [4], [$4], - [$0(m4_shift3($@))])]) - - -## ---------------------------------------- ## -## 6. Enhanced version of some primitives. ## -## ---------------------------------------- ## - -# m4_bpatsubsts(STRING, RE1, SUBST1, RE2, SUBST2, ...) -# ---------------------------------------------------- -# m4 equivalent of -# -# $_ = STRING; -# s/RE1/SUBST1/g; -# s/RE2/SUBST2/g; -# ... -# -# All the values are optional, and the macro is robust to active symbols -# properly quoted. -# -# I would have liked to name this macro `m4_bpatsubst', unfortunately, -# due to quotation problems, I need to double quote $1 below, therefore -# the anchors are broken :( I can't let users be trapped by that. -# -# Recall that m4_shift3 always results in an argument. Hence, we need -# to distinguish between a final deletion vs. ending recursion. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_bpatsubsts], -[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])], - [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])], - [$#], 2, [m4_unquote(m4_builtin([patsubst], [[$1]], [$2]))], - [$#], 3, [m4_unquote(m4_builtin([patsubst], [[$1]], [$2], [$3]))], - [_$0($@m4_if(m4_eval($# & 1), 0, [,]))])]) -m4_define([_m4_bpatsubsts], -[m4_if([$#], 2, [$1], - [$0(m4_builtin([patsubst], [[$1]], [$2], [$3]), - m4_shift3($@))])]) - - -# m4_define_default(MACRO, VALUE) -# ------------------------------- -# If MACRO is undefined, set it to VALUE. -m4_define([m4_define_default], -[m4_ifndef([$1], [m4_define($@)])]) - - -# m4_default(EXP1, EXP2) -# ---------------------- -# Returns EXP1 if non empty, otherwise EXP2. -# -# This macro is called on hot paths, so inline the contents of m4_ifval, -# for one less round of expansion. -m4_define([m4_default], -[m4_if([$1], [], [$2], [$1])]) - - -# m4_defn(NAME) -# ------------- -# Like the original, except guarantee a warning when using something which is -# undefined (unlike M4 1.4.x). This replacement is not a full-featured -# replacement: if any of the defined macros contain unbalanced quoting, but -# when pasted together result in a well-quoted string, then only native m4 -# support is able to get it correct. But that's where quadrigraphs come in -# handy, if you really need unbalanced quotes inside your macros. -# -# This macro is called frequently, so minimize the amount of additional -# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists, -# (added in M4 1.6), then let m4 do the job for us (see m4_init). -# -# _m4_defn is for internal use only - it bypasses the wrapper, so it -# must only be used on one argument at a time, and only on macros -# known to be defined. Make sure this still works if the user renames -# m4_defn but not _m4_defn. -m4_copy([m4_defn], [_m4_defn]) -m4_define([m4_defn], -[m4_if([$#], [0], [[$0]], - [$#], [1], [m4_ifdef([$1], [_m4_defn([$1])], - [m4_fatal([$0: undefined macro: $1])])], - [m4_foreach([_m4_macro], [$@], [$0(_m4_defn([_m4_macro]))])])]) - - -# _m4_dumpdefs_up(NAME) -# --------------------- -m4_define([_m4_dumpdefs_up], -[m4_ifdef([$1], - [m4_pushdef([_m4_dumpdefs], _m4_defn([$1]))dnl -m4_dumpdef([$1])dnl -_m4_popdef([$1])dnl -_m4_dumpdefs_up([$1])])]) - - -# _m4_dumpdefs_down(NAME) -# ----------------------- -m4_define([_m4_dumpdefs_down], -[m4_ifdef([_m4_dumpdefs], - [m4_pushdef([$1], _m4_defn([_m4_dumpdefs]))dnl -_m4_popdef([_m4_dumpdefs])dnl -_m4_dumpdefs_down([$1])])]) - - -# m4_dumpdefs(NAME) -# ----------------- -# Similar to `m4_dumpdef(NAME)', but if NAME was m4_pushdef'ed, display its -# value stack (most recent displayed first). -m4_define([m4_dumpdefs], -[_m4_dumpdefs_up([$1])dnl -_m4_dumpdefs_down([$1])]) - - -# m4_popdef(NAME) -# --------------- -# Like the original, except guarantee a warning when using something which is -# undefined (unlike M4 1.4.x). -# -# This macro is called frequently, so minimize the amount of additional -# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists, -# (added in M4 1.6), then let m4 do the job for us (see m4_init). -# -# _m4_popdef is for internal use only - it bypasses the wrapper, so it -# must only be used on macros known to be defined. Make sure this -# still works if the user renames m4_popdef but not _m4_popdef. -m4_copy([m4_popdef], [_m4_popdef]) -m4_define([m4_popdef], -[m4_if([$#], [0], [[$0]], - [$#], [1], [m4_ifdef([$1], [_m4_popdef([$1])], - [m4_fatal([$0: undefined macro: $1])])], - [m4_foreach([_m4_macro], [$@], [$0(_m4_defn([_m4_macro]))])])]) - - -# m4_shiftn(N, ...) -# ----------------- -# Returns ... shifted N times. Useful for recursive "varargs" constructs. -# -# Autoconf does not use this macro, because it is inherently slower than -# calling the common cases of m4_shift2 or m4_shift3 directly. But it -# might as well be fast for other clients, such as Libtool. One way to -# do this is to expand $@ only once in _m4_shiftn (otherwise, for long -# lists, the expansion of m4_if takes twice as much memory as what the -# list itself occupies, only to throw away the unused branch). The end -# result is strictly equivalent to -# m4_if([$1], 1, [m4_shift(,m4_shift(m4_shift($@)))], -# [_m4_shiftn(m4_decr([$1]), m4_shift(m4_shift($@)))]) -# but with the final `m4_shift(m4_shift($@)))' shared between the two -# paths. The first leg uses a no-op m4_shift(,$@) to balance out the (). -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_shiftn], -[m4_assert(0 < $1 && $1 < $#)_$0($@)]) - -m4_define([_m4_shiftn], -[m4_if([$1], 1, [m4_shift(], - [$0(m4_decr([$1])]), m4_shift(m4_shift($@)))]) - -# m4_shift2(...) -# m4_shift3(...) -# ----------------- -# Returns ... shifted twice, and three times. Faster than m4_shiftn. -m4_define([m4_shift2], [m4_shift(m4_shift($@))]) -m4_define([m4_shift3], [m4_shift(m4_shift(m4_shift($@)))]) - -# _m4_shift2(...) -# _m4_shift3(...) -# --------------- -# Like m4_shift2 or m4_shift3, except include a leading comma unless shifting -# consumes all arguments. Why? Because in recursion, it is nice to -# distinguish between 1 element left and 0 elements left, based on how many -# arguments this shift expands to. -m4_define([_m4_shift2], -[m4_if([$#], [2], [], - [, m4_shift(m4_shift($@))])]) -m4_define([_m4_shift3], -[m4_if([$#], [3], [], - [, m4_shift(m4_shift(m4_shift($@)))])]) - - -# m4_undefine(NAME) -# ----------------- -# Like the original, except guarantee a warning when using something which is -# undefined (unlike M4 1.4.x). -# -# This macro is called frequently, so minimize the amount of additional -# expansions by skipping m4_ifndef. Better yet, if __m4_version__ exists, -# (added in M4 1.6), then let m4 do the job for us (see m4_init). -# -# _m4_undefine is for internal use only - it bypasses the wrapper, so -# it must only be used on macros known to be defined. Make sure this -# still works if the user renames m4_undefine but not _m4_undefine. -m4_copy([m4_undefine], [_m4_undefine]) -m4_define([m4_undefine], -[m4_if([$#], [0], [[$0]], - [$#], [1], [m4_ifdef([$1], [_m4_undefine([$1])], - [m4_fatal([$0: undefined macro: $1])])], - [m4_foreach([_m4_macro], [$@], [$0(_m4_defn([_m4_macro]))])])]) - -# _m4_wrap(PRE, POST) -# ------------------- -# Helper macro for m4_wrap and m4_wrap_lifo. Allows nested calls to -# m4_wrap within wrapped text. Use _m4_defn and _m4_popdef for speed. -m4_define([_m4_wrap], -[m4_ifdef([$0_text], - [m4_define([$0_text], [$1]_m4_defn([$0_text])[$2])], - [m4_builtin([m4wrap], [m4_unquote( - _m4_defn([$0_text])_m4_popdef([$0_text]))])m4_define([$0_text], [$1$2])])]) - -# m4_wrap(TEXT) -# ------------- -# Append TEXT to the list of hooks to be executed at the end of input. -# Whereas the order of the original may be LIFO in the underlying m4, -# this version is always FIFO. -m4_define([m4_wrap], -[_m4_wrap([], [$1[]])]) - -# m4_wrap_lifo(TEXT) -# ------------------ -# Prepend TEXT to the list of hooks to be executed at the end of input. -# Whereas the order of m4_wrap may be FIFO in the underlying m4, this -# version is always LIFO. -m4_define([m4_wrap_lifo], -[_m4_wrap([$1[]])]) - -## ------------------------- ## -## 7. Quoting manipulation. ## -## ------------------------- ## - - -# m4_apply(MACRO, LIST) -# --------------------- -# Invoke MACRO, with arguments provided from the quoted list of -# comma-separated quoted arguments. If LIST is empty, invoke MACRO -# without arguments. The expansion will not be concatenated with -# subsequent text. -m4_define([m4_apply], -[m4_if([$2], [], [$1], [$1($2)])[]]) - -# _m4_apply(MACRO, LIST) -# ---------------------- -# Like m4_apply, except do nothing if LIST is empty. -m4_define([_m4_apply], -[m4_if([$2], [], [], [$1($2)[]])]) - - -# m4_count(ARGS) -# -------------- -# Return a count of how many ARGS are present. -m4_define([m4_count], [$#]) - - -# m4_do(STRING, ...) -# ------------------ -# This macro invokes all its arguments (in sequence, of course). It is -# useful for making your macros more structured and readable by dropping -# unnecessary dnl's and have the macros indented properly. No concatenation -# occurs after a STRING; use m4_unquote(m4_join(,STRING)) for that. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_do], -[m4_if([$#], 0, [], - [$#], 1, [$1[]], - [$1[]$0(m4_shift($@))])]) - - -# m4_dquote(ARGS) -# --------------- -# Return ARGS as a quoted list of quoted arguments. -m4_define([m4_dquote], [[$@]]) - - -# m4_dquote_elt(ARGS) -# ------------------- -# Return ARGS as an unquoted list of double-quoted arguments. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_dquote_elt], -[m4_if([$#], [0], [], - [$#], [1], [[[$1]]], - [[[$1]],$0(m4_shift($@))])]) - - -# m4_echo(ARGS) -# ------------- -# Return the ARGS, with the same level of quoting. Whitespace after -# unquoted commas are consumed. -m4_define([m4_echo], [$@]) - - -# m4_expand(ARG) -# -------------- -# Return the expansion of ARG as a single string. Unlike m4_quote($1), this -# correctly preserves whitespace following single-quoted commas that appeared -# within ARG. -# -# m4_define([active], [ACT, IVE]) -# m4_define([active2], [[ACT, IVE]]) -# m4_quote(active, active2) -# => ACT,IVE,ACT, IVE -# m4_expand([active, active2]) -# => ACT, IVE, ACT, IVE -# -# Unfortunately, due to limitations in m4, ARG must expand to something -# with balanced quotes (use quadrigraphs to get around this). The input -# is not likely to have unbalanced -=<{(/)}>=- quotes, and it is possible -# to have unbalanced (), provided it was specified with proper [] quotes. -# -# Exploit that extra () will group unquoted commas and the following -# whitespace, then convert () to []. m4_bpatsubst can't handle newlines -# inside $1, and m4_substr strips quoting. So we (ab)use m4_changequote. -m4_define([m4_expand], [_$0(-=<{($1)}>=-)]) -m4_define([_m4_expand], -[m4_changequote([-=<{(], [)}>=-])$1m4_changequote([, ])]) - - -# m4_ignore(ARGS) -# --------------- -# Expands to nothing. Useful for conditionally ignoring an arbitrary -# number of arguments (see _m4_list_cmp for an example). -m4_define([m4_ignore]) - - -# m4_make_list(ARGS) -# ------------------ -# Similar to m4_dquote, this creates a quoted list of quoted ARGS. This -# version is less efficient than m4_dquote, but separates each argument -# with a comma and newline, rather than just comma, for readability. -# When developing an m4sugar algorithm, you could temporarily use -# m4_pushdef([m4_dquote],m4_defn([m4_make_list])) -# around your code to make debugging easier. -m4_define([m4_make_list], [m4_join([, -], m4_dquote_elt($@))]) - - -# m4_noquote(STRING) -# ------------------ -# Return the result of ignoring all quotes in STRING and invoking the -# macros it contains. Amongst other things, this is useful for enabling -# macro invocations inside strings with [] blocks (for instance regexps -# and help-strings). On the other hand, since all quotes are disabled, -# any macro expanded during this time that relies on nested [] quoting -# will likely crash and burn. This macro is seldom useful; consider -# m4_unquote or m4_expand instead. -m4_define([m4_noquote], -[m4_changequote([-=<{(],[)}>=-])$1-=<{()}>=-m4_changequote([,])]) - - -# m4_quote(ARGS) -# -------------- -# Return ARGS as a single argument. Any whitespace after unquoted commas -# is stripped. There is always output, even when there were no arguments. -# -# It is important to realize the difference between `m4_quote(exp)' and -# `[exp]': in the first case you obtain the quoted *result* of the -# expansion of EXP, while in the latter you just obtain the string -# `exp'. -m4_define([m4_quote], [[$*]]) - - -# _m4_quote(ARGS) -# --------------- -# Like m4_quote, except that when there are no arguments, there is no -# output. For conditional scenarios (such as passing _m4_quote as the -# macro name in m4_mapall), this feature can be used to distinguish between -# one argument of the empty string vs. no arguments. However, in the -# normal case with arguments present, this is less efficient than m4_quote. -m4_define([_m4_quote], -[m4_if([$#], [0], [], [[$*]])]) - - -# m4_reverse(ARGS) -# ---------------- -# Output ARGS in reverse order. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_reverse], -[m4_if([$#], [0], [], [$#], [1], [[$1]], - [$0(m4_shift($@)), [$1]])]) - - -# m4_unquote(ARGS) -# ---------------- -# Remove one layer of quotes from each ARG, performing one level of -# expansion. For one argument, m4_unquote([arg]) is more efficient than -# m4_do([arg]), but for multiple arguments, the difference is that -# m4_unquote separates arguments with commas while m4_do concatenates. -# Follow this macro with [] if concatenation with subsequent text is -# undesired. -m4_define([m4_unquote], [$*]) - - -## -------------------------- ## -## 8. Implementing m4 loops. ## -## -------------------------- ## - - -# m4_for(VARIABLE, FIRST, LAST, [STEP = +/-1], EXPRESSION) -# -------------------------------------------------------- -# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO with -# increments of STEP. Both limits are included, and bounds are -# checked for consistency. The algorithm is robust to indirect -# VARIABLE names. Changing VARIABLE inside EXPRESSION will not impact -# the number of iterations. -# -# Uses _m4_defn for speed, and avoid dnl in the macro body. -m4_define([m4_for], -[m4_pushdef([$1], m4_eval([$2]))]dnl -[m4_cond([m4_eval(([$3]) > ([$2]))], 1, - [m4_pushdef([_m4_step], m4_eval(m4_default([$4], - 1)))m4_assert(_m4_step > 0)_$0([$1], _m4_defn([$1]), - m4_eval((([$3]) - ([$2])) / _m4_step * _m4_step + ([$2])), - _m4_step, [$5])], - [m4_eval(([$3]) < ([$2]))], 1, - [m4_pushdef([_m4_step], m4_eval(m4_default([$4], - -1)))m4_assert(_m4_step < 0)_$0([$1], _m4_defn([$1]), - m4_eval((([$2]) - ([$3])) / -(_m4_step) * _m4_step + ([$2])), - _m4_step, [$5])], - [m4_pushdef([_m4_step])$5])[]]dnl -[m4_popdef([_m4_step], [$1])]) - - -# _m4_for(VARIABLE, COUNT, LAST, STEP, EXPRESSION) -# ------------------------------------------------ -# Core of the loop, no consistency checks, all arguments are plain -# numbers. Define VARIABLE to COUNT, expand EXPRESSION, then alter -# COUNT by STEP and iterate if COUNT is not LAST. -m4_define([_m4_for], -[m4_define([$1], [$2])$5[]m4_if([$2], [$3], [], - [$0([$1], m4_eval([$2 + $4]), [$3], [$4], [$5])])]) - - -# Implementing `foreach' loops in m4 is much more tricky than it may -# seem. For example, the old M4 1.4.4 manual had an incorrect example, -# which looked like this (when translated to m4sugar): -# -# | # foreach(VAR, (LIST), STMT) -# | m4_define([foreach], -# | [m4_pushdef([$1])_foreach([$1], [$2], [$3])m4_popdef([$1])]) -# | m4_define([_arg1], [$1]) -# | m4_define([_foreach], -# | [m4_if([$2], [()], , -# | [m4_define([$1], _arg1$2)$3[]_foreach([$1], (m4_shift$2), [$3])])]) -# -# But then if you run -# -# | m4_define(a, 1) -# | m4_define(b, 2) -# | m4_define(c, 3) -# | foreach([f], [([a], [(b], [c)])], [echo f -# | ]) -# -# it gives -# -# => echo 1 -# => echo (2,3) -# -# which is not what is expected. -# -# Of course the problem is that many quotes are missing. So you add -# plenty of quotes at random places, until you reach the expected -# result. Alternatively, if you are a quoting wizard, you directly -# reach the following implementation (but if you really did, then -# apply to the maintenance of m4sugar!). -# -# | # foreach(VAR, (LIST), STMT) -# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])]) -# | m4_define([_arg1], [[$1]]) -# | m4_define([_foreach], -# | [m4_if($2, [()], , -# | [m4_define([$1], [_arg1$2])$3[]_foreach([$1], [(m4_shift$2)], [$3])])]) -# -# which this time answers -# -# => echo a -# => echo (b -# => echo c) -# -# Bingo! -# -# Well, not quite. -# -# With a better look, you realize that the parens are more a pain than -# a help: since anyway you need to quote properly the list, you end up -# with always using an outermost pair of parens and an outermost pair -# of quotes. Rejecting the parens both eases the implementation, and -# simplifies the use: -# -# | # foreach(VAR, (LIST), STMT) -# | m4_define([foreach], [m4_pushdef([$1])_foreach($@)m4_popdef([$1])]) -# | m4_define([_arg1], [$1]) -# | m4_define([_foreach], -# | [m4_if($2, [], , -# | [m4_define([$1], [_arg1($2)])$3[]_foreach([$1], [m4_shift($2)], [$3])])]) -# -# -# Now, just replace the `$2' with `m4_quote($2)' in the outer `m4_if' -# to improve robustness, and you come up with a nice implementation -# that doesn't require extra parentheses in the user's LIST. -# -# But wait - now the algorithm is quadratic, because every recursion of -# the algorithm keeps the entire LIST and merely adds another m4_shift to -# the quoted text. If the user has a lot of elements in LIST, you can -# bring the system to its knees with the memory m4 then requires, or trip -# the m4 --nesting-limit recursion factor. The only way to avoid -# quadratic growth is ensure m4_shift is expanded prior to the recursion. -# Hence the design below. -# -# The M4 manual now includes a chapter devoted to this issue, with -# the lessons learned from m4sugar. And still, this design is only -# optimal for M4 1.6; see foreach.m4 for yet more comments on why -# M4 1.4.x uses yet another implementation. - - -# m4_foreach(VARIABLE, LIST, EXPRESSION) -# -------------------------------------- -# -# Expand EXPRESSION assigning each value of the LIST to VARIABLE. -# LIST should have the form `item_1, item_2, ..., item_n', i.e. the -# whole list must *quoted*. Quote members too if you don't want them -# to be expanded. -# -# This macro is robust to active symbols: -# | m4_define(active, [ACT, IVE]) -# | m4_foreach(Var, [active, active], [-Var-]) -# => -ACT--IVE--ACT--IVE- -# -# | m4_foreach(Var, [[active], [active]], [-Var-]) -# => -ACT, IVE--ACT, IVE- -# -# | m4_foreach(Var, [[[active]], [[active]]], [-Var-]) -# => -active--active- -# -# This macro is called frequently, so avoid extra expansions such as -# m4_ifval and dnl. Also, since $2 might be quite large, try to use it -# as little as possible in _m4_foreach; each extra use requires that much -# more memory for expansion. So, rather than directly compare $2 against -# [] and use m4_car/m4_cdr for recursion, we instead unbox the list (which -# requires swapping the argument order in the helper), insert an ignored -# third argument, and use m4_shift3 to detect when recursion is complete. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_foreach], -[m4_if([$2], [], [], - [m4_pushdef([$1])_$0([$1], [$3], [], $2)m4_popdef([$1])])]) - -m4_define([_m4_foreach], -[m4_if([$#], [3], [], - [m4_define([$1], [$4])$2[]$0([$1], [$2], m4_shift3($@))])]) - - -# m4_foreach_w(VARIABLE, LIST, EXPRESSION) -# ---------------------------------------- -# -# Like m4_foreach, but the list is whitespace separated. -# -# This macro is robust to active symbols: -# m4_foreach_w([Var], [ active -# b act\ -# ive ], [-Var-])end -# => -active--b--active-end -# -m4_define([m4_foreach_w], -[m4_foreach([$1], m4_split(m4_normalize([$2]), [ ]), [$3])]) - - -# m4_map(MACRO, LIST) -# m4_mapall(MACRO, LIST) -# ---------------------- -# Invoke MACRO($1), MACRO($2) etc. where $1, $2... are the elements of -# LIST. $1, $2... must in turn be lists, appropriate for m4_apply. -# If LIST contains an empty sublist, m4_map skips the expansion of -# MACRO, while m4_mapall expands MACRO with no arguments. -# -# Since LIST may be quite large, we want to minimize how often it -# appears in the expansion. Rather than use m4_car/m4_cdr iteration, -# we unbox the list, ignore the second argument, and use m4_shift2 to -# detect the end of recursion. The mismatch in () is intentional; see -# _m4_map. For m4_map, an empty list behaves like an empty sublist -# and gets ignored; for m4_mapall, we must special-case the empty -# list. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_map], -[_m4_map([_m4_apply([$1]], [], $2)]) - -m4_define([m4_mapall], -[m4_if([$2], [], [], - [_m4_map([m4_apply([$1]], [], $2)])]) - - -# m4_map_sep(MACRO, SEPARATOR, LIST) -# m4_mapall_sep(MACRO, SEPARATOR, LIST) -# ------------------------------------- -# Invoke MACRO($1), SEPARATOR, MACRO($2), ..., MACRO($N) where $1, -# $2... $N are the elements of LIST, and are in turn lists appropriate -# for m4_apply. SEPARATOR is expanded, in order to allow the creation -# of a list of arguments by using a single-quoted comma as the -# separator. For each empty sublist, m4_map_sep skips the expansion -# of MACRO and SEPARATOR, while m4_mapall_sep expands MACRO with no -# arguments. -# -# For m4_mapall_sep, merely expand the first iteration without the -# separator, then include separator as part of subsequent recursion; -# but avoid extra expansion of LIST's side-effects via a helper macro. -# For m4_map_sep, things are trickier - we don't know if the first -# list element is an empty sublist, so we must define a self-modifying -# helper macro and use that as the separator instead. -m4_define([m4_map_sep], -[m4_pushdef([m4_Sep], [m4_define([m4_Sep], _m4_defn([m4_unquote]))])]dnl -[_m4_map([_m4_apply([m4_Sep([$2])[]$1]], [], $3)m4_popdef([m4_Sep])]) - -m4_define([m4_mapall_sep], -[m4_if([$3], [], [], [_$0([$1], [$2], $3)])]) - -m4_define([_m4_mapall_sep], -[m4_apply([$1], [$3])_m4_map([m4_apply([$2[]$1]], m4_shift2($@))]) - -# _m4_map(PREFIX, IGNORED, SUBLIST, ...) -# -------------------------------------- -# Common implementation for all four m4_map variants. The mismatch in -# the number of () is intentional. PREFIX must supply a form of -# m4_apply, the open `(', and the MACRO to be applied. Each iteration -# then appends `,', the current SUBLIST and the closing `)', then -# recurses to the next SUBLIST. IGNORED is an aid to ending recursion -# efficiently. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([_m4_map], -[m4_if([$#], [2], [], - [$1, [$3])$0([$1], m4_shift2($@))])]) - -# m4_transform(EXPRESSION, ARG...) -# -------------------------------- -# Expand EXPRESSION([ARG]) for each argument. More efficient than -# m4_foreach([var], [ARG...], [EXPRESSION(m4_defn([var]))]) -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_transform], -[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])], - [$#], [1], [], - [$#], [2], [$1([$2])[]], - [$1([$2])[]$0([$1], m4_shift2($@))])]) - - -# m4_transform_pair(EXPRESSION, [END-EXPR = EXPRESSION], ARG...) -# -------------------------------------------------------------- -# Perform a pairwise grouping of consecutive ARGs, by expanding -# EXPRESSION([ARG1], [ARG2]). If there are an odd number of ARGs, the -# final argument is expanded with END-EXPR([ARGn]). -# -# For example: -# m4_define([show], [($*)m4_newline])dnl -# m4_transform_pair([show], [], [a], [b], [c], [d], [e])dnl -# => (a,b) -# => (c,d) -# => (e) -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_transform_pair], -[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])], - [$#], [1], [m4_fatal([$0: too few arguments: $#: $1])], - [$#], [2], [], - [$#], [3], [m4_default([$2], [$1])([$3])[]], - [$#], [4], [$1([$3], [$4])[]], - [$1([$3], [$4])[]$0([$1], [$2], m4_shift(m4_shift3($@)))])]) - - -## --------------------------- ## -## 9. More diversion support. ## -## --------------------------- ## - - -# _m4_divert(DIVERSION-NAME or NUMBER) -# ------------------------------------ -# If DIVERSION-NAME is the name of a diversion, return its number, -# otherwise if it is a NUMBER return it. -m4_define([_m4_divert], -[m4_ifdef([_m4_divert($1)], - [m4_indir([_m4_divert($1)])], - [$1])]) - -# KILL is only used to suppress output. -m4_define([_m4_divert(KILL)], -1) - -# The empty diversion name is a synonym for 0. -m4_define([_m4_divert()], 0) - - -# _m4_divert_n_stack -# ------------------ -# Print m4_divert_stack with newline prepended, if it's nonempty. -m4_define([_m4_divert_n_stack], -[m4_ifdef([m4_divert_stack], [ -_m4_defn([m4_divert_stack])])]) - - -# m4_divert(DIVERSION-NAME) -# ------------------------- -# Change the diversion stream to DIVERSION-NAME. -m4_define([m4_divert], -[m4_define([m4_divert_stack], m4_location[: $0: $1]_m4_divert_n_stack)]dnl -[m4_builtin([divert], _m4_divert([$1]))]) - - -# m4_divert_push(DIVERSION-NAME) -# ------------------------------ -# Change the diversion stream to DIVERSION-NAME, while stacking old values. -m4_define([m4_divert_push], -[m4_pushdef([m4_divert_stack], m4_location[: $0: $1]_m4_divert_n_stack)]dnl -[m4_pushdef([_m4_divert_diversion], [$1])]dnl -[m4_builtin([divert], _m4_divert([$1]))]) - - -# m4_divert_pop([DIVERSION-NAME]) -# ------------------------------- -# Change the diversion stream to its previous value, unstacking it. -# If specified, verify we left DIVERSION-NAME. -# When we pop the last value from the stack, we divert to -1. -m4_define([m4_divert_pop], -[m4_ifndef([_m4_divert_diversion], - [m4_fatal([too many m4_divert_pop])])]dnl -[m4_if([$1], [], [], - [$1], _m4_defn([_m4_divert_diversion]), [], - [m4_fatal([$0($1): diversion mismatch: ]_m4_divert_n_stack)])]dnl -[_m4_popdef([m4_divert_stack], [_m4_divert_diversion])]dnl -[m4_builtin([divert], - m4_ifdef([_m4_divert_diversion], - [_m4_divert(_m4_defn([_m4_divert_diversion]))], - -1))]) - - -# m4_divert_text(DIVERSION-NAME, CONTENT) -# --------------------------------------- -# Output CONTENT into DIVERSION-NAME (which may be a number actually). -# An end of line is appended for free to CONTENT. -m4_define([m4_divert_text], -[m4_divert_push([$1])$2 -m4_divert_pop([$1])]) - - -# m4_divert_once(DIVERSION-NAME, CONTENT) -# --------------------------------------- -# Output CONTENT into DIVERSION-NAME once, if not already there. -# An end of line is appended for free to CONTENT. -m4_define([m4_divert_once], -[m4_expand_once([m4_divert_text([$1], [$2])])]) - - -# m4_undivert(DIVERSION-NAME) -# --------------------------- -# Undivert DIVERSION-NAME. Unlike the M4 version, this only takes a single -# diversion identifier, and should not be used to undivert files. -m4_define([m4_undivert], -[m4_builtin([undivert], _m4_divert([$1]))]) - - -## --------------------------------------------- ## -## 10. Defining macros with bells and whistles. ## -## --------------------------------------------- ## - -# `m4_defun' is basically `m4_define' but it equips the macro with the -# needed machinery for `m4_require'. A macro must be m4_defun'd if -# either it is m4_require'd, or it m4_require's. -# -# Two things deserve attention and are detailed below: -# 1. Implementation of m4_require -# 2. Keeping track of the expansion stack -# -# 1. Implementation of m4_require -# =============================== -# -# Of course m4_defun AC_PROVIDE's the macro, so that a macro which has -# been expanded is not expanded again when m4_require'd, but the -# difficult part is the proper expansion of macros when they are -# m4_require'd. -# -# The implementation is based on two ideas, (i) using diversions to -# prepare the expansion of the macro and its dependencies (by Franc,ois -# Pinard), and (ii) expand the most recently m4_require'd macros _after_ -# the previous macros (by Axel Thimm). -# -# -# The first idea: why use diversions? -# ----------------------------------- -# -# When a macro requires another, the other macro is expanded in new -# diversion, GROW. When the outer macro is fully expanded, we first -# undivert the most nested diversions (GROW - 1...), and finally -# undivert GROW. To understand why we need several diversions, -# consider the following example: -# -# | m4_defun([TEST1], [Test...REQUIRE([TEST2])1]) -# | m4_defun([TEST2], [Test...REQUIRE([TEST3])2]) -# | m4_defun([TEST3], [Test...3]) -# -# Because m4_require is not required to be first in the outer macros, we -# must keep the expansions of the various levels of m4_require separated. -# Right before executing the epilogue of TEST1, we have: -# -# GROW - 2: Test...3 -# GROW - 1: Test...2 -# GROW: Test...1 -# BODY: -# -# Finally the epilogue of TEST1 undiverts GROW - 2, GROW - 1, and -# GROW into the regular flow, BODY. -# -# GROW - 2: -# GROW - 1: -# GROW: -# BODY: Test...3; Test...2; Test...1 -# -# (The semicolons are here for clarification, but of course are not -# emitted.) This is what Autoconf 2.0 (I think) to 2.13 (I'm sure) -# implement. -# -# -# The second idea: first required first out -# ----------------------------------------- -# -# The natural implementation of the idea above is buggy and produces -# very surprising results in some situations. Let's consider the -# following example to explain the bug: -# -# | m4_defun([TEST1], [REQUIRE([TEST2a])REQUIRE([TEST2b])]) -# | m4_defun([TEST2a], []) -# | m4_defun([TEST2b], [REQUIRE([TEST3])]) -# | m4_defun([TEST3], [REQUIRE([TEST2a])]) -# | -# | AC_INIT -# | TEST1 -# -# The dependencies between the macros are: -# -# 3 --- 2b -# / \ is m4_require'd by -# / \ left -------------------- right -# 2a ------------ 1 -# -# If you strictly apply the rules given in the previous section you get: -# -# GROW - 2: TEST3 -# GROW - 1: TEST2a; TEST2b -# GROW: TEST1 -# BODY: -# -# (TEST2a, although required by TEST3 is not expanded in GROW - 3 -# because is has already been expanded before in GROW - 1, so it has -# been AC_PROVIDE'd, so it is not expanded again) so when you undivert -# the stack of diversions, you get: -# -# GROW - 2: -# GROW - 1: -# GROW: -# BODY: TEST3; TEST2a; TEST2b; TEST1 -# -# i.e., TEST2a is expanded after TEST3 although the latter required the -# former. -# -# Starting from 2.50, we use an implementation provided by Axel Thimm. -# The idea is simple: the order in which macros are emitted must be the -# same as the one in which macros are expanded. (The bug above can -# indeed be described as: a macro has been AC_PROVIDE'd before its -# dependent, but it is emitted after: the lack of correlation between -# emission and expansion order is guilty). -# -# How to do that? You keep the stack of diversions to elaborate the -# macros, but each time a macro is fully expanded, emit it immediately. -# -# In the example above, when TEST2a is expanded, but it's epilogue is -# not run yet, you have: -# -# GROW - 2: -# GROW - 1: TEST2a -# GROW: Elaboration of TEST1 -# BODY: -# -# The epilogue of TEST2a emits it immediately: -# -# GROW - 2: -# GROW - 1: -# GROW: Elaboration of TEST1 -# BODY: TEST2a -# -# TEST2b then requires TEST3, so right before the epilogue of TEST3, you -# have: -# -# GROW - 2: TEST3 -# GROW - 1: Elaboration of TEST2b -# GROW: Elaboration of TEST1 -# BODY: TEST2a -# -# The epilogue of TEST3 emits it: -# -# GROW - 2: -# GROW - 1: Elaboration of TEST2b -# GROW: Elaboration of TEST1 -# BODY: TEST2a; TEST3 -# -# TEST2b is now completely expanded, and emitted: -# -# GROW - 2: -# GROW - 1: -# GROW: Elaboration of TEST1 -# BODY: TEST2a; TEST3; TEST2b -# -# and finally, TEST1 is finished and emitted: -# -# GROW - 2: -# GROW - 1: -# GROW: -# BODY: TEST2a; TEST3; TEST2b: TEST1 -# -# The idea is simple, but the implementation is a bit evolved. If you -# are like me, you will want to see the actual functioning of this -# implementation to be convinced. The next section gives the full -# details. -# -# -# The Axel Thimm implementation at work -# ------------------------------------- -# -# We consider the macros above, and this configure.ac: -# -# AC_INIT -# TEST1 -# -# You should keep the definitions of _m4_defun_pro, _m4_defun_epi, and -# m4_require at hand to follow the steps. -# -# This implements tries not to assume that the current diversion is -# BODY, so as soon as a macro (m4_defun'd) is expanded, we first -# record the current diversion under the name _m4_divert_dump (denoted -# DUMP below for short). This introduces an important difference with -# the previous versions of Autoconf: you cannot use m4_require if you -# are not inside an m4_defun'd macro, and especially, you cannot -# m4_require directly from the top level. -# -# We have not tried to simulate the old behavior (better yet, we -# diagnose it), because it is too dangerous: a macro m4_require'd from -# the top level is expanded before the body of `configure', i.e., before -# any other test was run. I let you imagine the result of requiring -# AC_STDC_HEADERS for instance, before AC_PROG_CC was actually run.... -# -# After AC_INIT was run, the current diversion is BODY. -# * AC_INIT was run -# DUMP: undefined -# diversion stack: BODY |- -# -# * TEST1 is expanded -# The prologue of TEST1 sets _m4_divert_dump, which is the diversion -# where the current elaboration will be dumped, to the current -# diversion. It also m4_divert_push to GROW, where the full -# expansion of TEST1 and its dependencies will be elaborated. -# DUMP: BODY -# BODY: empty -# diversions: GROW, BODY |- -# -# * TEST1 requires TEST2a -# _m4_require_call m4_divert_pushes another temporary diversion, -# GROW - 1, and expands TEST2a in there. -# DUMP: BODY -# BODY: empty -# GROW - 1: TEST2a -# diversions: GROW - 1, GROW, BODY |- -# Than the content of the temporary diversion is moved to DUMP and the -# temporary diversion is popped. -# DUMP: BODY -# BODY: TEST2a -# diversions: GROW, BODY |- -# -# * TEST1 requires TEST2b -# Again, _m4_require_call pushes GROW - 1 and heads to expand TEST2b. -# DUMP: BODY -# BODY: TEST2a -# diversions: GROW - 1, GROW, BODY |- -# -# * TEST2b requires TEST3 -# _m4_require_call pushes GROW - 2 and expands TEST3 here. -# (TEST3 requires TEST2a, but TEST2a has already been m4_provide'd, so -# nothing happens.) -# DUMP: BODY -# BODY: TEST2a -# GROW - 2: TEST3 -# diversions: GROW - 2, GROW - 1, GROW, BODY |- -# Than the diversion is appended to DUMP, and popped. -# DUMP: BODY -# BODY: TEST2a; TEST3 -# diversions: GROW - 1, GROW, BODY |- -# -# * TEST1 requires TEST2b (contd.) -# The content of TEST2b is expanded... -# DUMP: BODY -# BODY: TEST2a; TEST3 -# GROW - 1: TEST2b, -# diversions: GROW - 1, GROW, BODY |- -# ... and moved to DUMP. -# DUMP: BODY -# BODY: TEST2a; TEST3; TEST2b -# diversions: GROW, BODY |- -# -# * TEST1 is expanded: epilogue -# TEST1's own content is in GROW... -# DUMP: BODY -# BODY: TEST2a; TEST3; TEST2b -# GROW: TEST1 -# diversions: BODY |- -# ... and it's epilogue moves it to DUMP and then undefines DUMP. -# DUMP: undefined -# BODY: TEST2a; TEST3; TEST2b; TEST1 -# diversions: BODY |- -# -# -# 2. Keeping track of the expansion stack -# ======================================= -# -# When M4 expansion goes wrong it is often extremely hard to find the -# path amongst macros that drove to the failure. What is needed is -# the stack of macro `calls'. One could imagine that GNU M4 would -# maintain a stack of macro expansions, unfortunately it doesn't, so -# we do it by hand. This is of course extremely costly, but the help -# this stack provides is worth it. Nevertheless to limit the -# performance penalty this is implemented only for m4_defun'd macros, -# not for define'd macros. -# -# The scheme is simplistic: each time we enter an m4_defun'd macros, -# we prepend its name in m4_expansion_stack, and when we exit the -# macro, we remove it (thanks to pushdef/popdef). -# -# In addition, we want to detect circular m4_require dependencies. -# Each time we expand a macro FOO we define _m4_expanding(FOO); and -# m4_require(BAR) simply checks whether _m4_expanding(BAR) is defined. - - -# m4_expansion_stack_push(TEXT) -# ----------------------------- -m4_define([m4_expansion_stack_push], -[m4_pushdef([m4_expansion_stack], - [$1]m4_ifdef([m4_expansion_stack], [ -_m4_defn([m4_expansion_stack])]))]) - - -# m4_expansion_stack_pop -# ---------------------- -m4_define([m4_expansion_stack_pop], -[m4_popdef([m4_expansion_stack])]) - - -# m4_expansion_stack_dump -# ----------------------- -# Dump the expansion stack. -m4_define([m4_expansion_stack_dump], -[m4_ifdef([m4_expansion_stack], - [m4_errprintn(_m4_defn([m4_expansion_stack]))])dnl -m4_errprintn(m4_location[: the top level])]) - - -# _m4_divert(GROW) -# ---------------- -# This diversion is used by the m4_defun/m4_require machinery. It is -# important to keep room before GROW because for each nested -# AC_REQUIRE we use an additional diversion (i.e., two m4_require's -# will use GROW - 2. More than 3 levels has never seemed to be -# needed.) -# -# ... -# - GROW - 2 -# m4_require'd code, 2 level deep -# - GROW - 1 -# m4_require'd code, 1 level deep -# - GROW -# m4_defun'd macros are elaborated here. - -m4_define([_m4_divert(GROW)], 10000) - - -# _m4_defun_pro(MACRO-NAME) -# ------------------------- -# The prologue for Autoconf macros. -# -# This is called frequently, so minimize the number of macro invocations -# by avoiding dnl and m4_defn overhead. -m4_define([_m4_defun_pro], -m4_do([[m4_ifdef([m4_expansion_stack], [], [_m4_defun_pro_outer[]])]], - [[m4_expansion_stack_push(_m4_defn( - [m4_location($1)])[: $1 is expanded from...])]], - [[m4_pushdef([_m4_expanding($1)])]])) - -m4_define([_m4_defun_pro_outer], -[m4_copy([_m4_divert_diversion], [_m4_divert_dump])m4_divert_push([GROW])]) - -# _m4_defun_epi(MACRO-NAME) -# ------------------------- -# The Epilogue for Autoconf macros. MACRO-NAME only helps tracing -# the PRO/EPI pairs. -# -# This is called frequently, so minimize the number of macro invocations -# by avoiding dnl and m4_popdef overhead. -m4_define([_m4_defun_epi], -m4_do([[_m4_popdef([_m4_expanding($1)])]], - [[m4_expansion_stack_pop()]], - [[m4_ifdef([m4_expansion_stack], [], [_m4_defun_epi_outer[]])]], - [[m4_provide([$1])]])) - -m4_define([_m4_defun_epi_outer], -[_m4_undefine([_m4_divert_dump])m4_divert_pop([GROW])m4_undivert([GROW])]) - - -# m4_defun(NAME, EXPANSION) -# ------------------------- -# Define a macro which automatically provides itself. Add machinery -# so the macro automatically switches expansion to the diversion -# stack if it is not already using it. In this case, once finished, -# it will bring back all the code accumulated in the diversion stack. -# This, combined with m4_require, achieves the topological ordering of -# macros. We don't use this macro to define some frequently called -# macros that are not involved in ordering constraints, to save m4 -# processing. -m4_define([m4_defun], -[m4_define([m4_location($1)], m4_location)dnl -m4_define([$1], - [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])]) - - -# m4_defun_once(NAME, EXPANSION) -# ------------------------------ -# As m4_defun, but issues the EXPANSION only once, and warns if used -# several times. -m4_define([m4_defun_once], -[m4_define([m4_location($1)], m4_location)dnl -m4_define([$1], - [m4_provide_if([$1], - [m4_warn([syntax], [$1 invoked multiple times])], - [_m4_defun_pro([$1])$2[]_m4_defun_epi([$1])])])]) - - -# m4_pattern_forbid(ERE, [WHY]) -# ----------------------------- -# Declare that no token matching the forbidden extended regular -# expression ERE should be seen in the output unless... -m4_define([m4_pattern_forbid], []) - - -# m4_pattern_allow(ERE) -# --------------------- -# ... that token also matches the allowed extended regular expression ERE. -# Both used via traces. -m4_define([m4_pattern_allow], []) - - -## --------------------------------- ## -## 11. Dependencies between macros. ## -## --------------------------------- ## - - -# m4_before(THIS-MACRO-NAME, CALLED-MACRO-NAME) -# --------------------------------------------- -# Issue a warning if CALLED-MACRO-NAME was called before THIS-MACRO-NAME. -m4_define([m4_before], -[m4_provide_if([$2], - [m4_warn([syntax], [$2 was called before $1])])]) - - -# m4_require(NAME-TO-CHECK, [BODY-TO-EXPAND = NAME-TO-CHECK]) -# ----------------------------------------------------------- -# If NAME-TO-CHECK has never been expanded (actually, if it is not -# m4_provide'd), expand BODY-TO-EXPAND *before* the current macro -# expansion. Once expanded, emit it in _m4_divert_dump. Keep track -# of the m4_require chain in m4_expansion_stack. -# -# The normal cases are: -# -# - NAME-TO-CHECK == BODY-TO-EXPAND -# Which you can use for regular macros with or without arguments, e.g., -# m4_require([AC_PROG_CC], [AC_PROG_CC]) -# m4_require([AC_CHECK_HEADERS(limits.h)], [AC_CHECK_HEADERS(limits.h)]) -# which is just the same as -# m4_require([AC_PROG_CC]) -# m4_require([AC_CHECK_HEADERS(limits.h)]) -# -# - BODY-TO-EXPAND == m4_indir([NAME-TO-CHECK]) -# In the case of macros with irregular names. For instance: -# m4_require([AC_LANG_COMPILER(C)], [indir([AC_LANG_COMPILER(C)])]) -# which means `if the macro named `AC_LANG_COMPILER(C)' (the parens are -# part of the name, it is not an argument) has not been run, then -# call it.' -# Had you used -# m4_require([AC_LANG_COMPILER(C)], [AC_LANG_COMPILER(C)]) -# then m4_require would have tried to expand `AC_LANG_COMPILER(C)', i.e., -# call the macro `AC_LANG_COMPILER' with `C' as argument. -# -# You could argue that `AC_LANG_COMPILER', when it receives an argument -# such as `C' should dispatch the call to `AC_LANG_COMPILER(C)'. But this -# `extension' prevents `AC_LANG_COMPILER' from having actual arguments that -# it passes to `AC_LANG_COMPILER(C)'. -# -# This is called frequently, so minimize the number of macro invocations -# by avoiding dnl and other overhead on the common path. -m4_define([m4_require], -m4_do([[m4_ifdef([_m4_expanding($1)], - [m4_fatal([$0: circular dependency of $1])])]], - [[m4_ifdef([_m4_divert_dump], [], - [m4_fatal([$0($1): cannot be used outside of an ]dnl -m4_bmatch([$0], [^AC_], [[AC_DEFUN]], [[m4_defun]])['d macro])])]], - [[m4_provide_if([$1], - [], - [_m4_require_call([$1], [$2])])]])) - - -# _m4_require_call(NAME-TO-CHECK, [BODY-TO-EXPAND = NAME-TO-CHECK]) -# ----------------------------------------------------------------- -# If m4_require decides to expand the body, it calls this macro. -# -# This is called frequently, so minimize the number of macro invocations -# by avoiding dnl and other overhead on the common path. -m4_define([_m4_require_call], -m4_do([[m4_define([_m4_divert_grow], m4_decr(_m4_divert_grow))]], - [[m4_divert_push(_m4_divert_grow)]], - [[m4_default([$2], [$1]) -m4_provide_if([$1], - [], - [m4_warn([syntax], - [$1 is m4_require'd but not m4_defun'd])])]], - [[m4_divert(_m4_defn([_m4_divert_dump]))]], - [[m4_undivert(_m4_divert_grow)]], - [[m4_divert_pop(_m4_divert_grow)]], - [[m4_define([_m4_divert_grow], m4_incr(_m4_divert_grow))]])) - - -# _m4_divert_grow -# --------------- -# The counter for _m4_require_call. -m4_define([_m4_divert_grow], _m4_divert([GROW])) - - -# m4_expand_once(TEXT, [WITNESS = TEXT]) -# -------------------------------------- -# If TEXT has never been expanded, expand it *here*. Use WITNESS as -# as a memory that TEXT has already been expanded. -m4_define([m4_expand_once], -[m4_provide_if(m4_ifval([$2], [[$2]], [[$1]]), - [], - [m4_provide(m4_ifval([$2], [[$2]], [[$1]]))[]$1])]) - - -# m4_provide(MACRO-NAME) -# ---------------------- -m4_define([m4_provide], -[m4_define([m4_provide($1)])]) - - -# m4_provide_if(MACRO-NAME, IF-PROVIDED, IF-NOT-PROVIDED) -# ------------------------------------------------------- -# If MACRO-NAME is provided do IF-PROVIDED, else IF-NOT-PROVIDED. -# The purpose of this macro is to provide the user with a means to -# check macros which are provided without letting her know how the -# information is coded. -m4_define([m4_provide_if], -[m4_ifdef([m4_provide($1)], - [$2], [$3])]) - - -## --------------------- ## -## 12. Text processing. ## -## --------------------- ## - - -# m4_cr_letters -# m4_cr_LETTERS -# m4_cr_Letters -# ------------- -m4_define([m4_cr_letters], [abcdefghijklmnopqrstuvwxyz]) -m4_define([m4_cr_LETTERS], [ABCDEFGHIJKLMNOPQRSTUVWXYZ]) -m4_define([m4_cr_Letters], -m4_defn([m4_cr_letters])dnl -m4_defn([m4_cr_LETTERS])dnl -) - - -# m4_cr_digits -# ------------ -m4_define([m4_cr_digits], [0123456789]) - - -# m4_cr_alnum -# ----------- -m4_define([m4_cr_alnum], -m4_defn([m4_cr_Letters])dnl -m4_defn([m4_cr_digits])dnl -) - - -# m4_cr_symbols1 -# m4_cr_symbols2 -# ------------------------------- -m4_define([m4_cr_symbols1], -m4_defn([m4_cr_Letters])dnl -_) - -m4_define([m4_cr_symbols2], -m4_defn([m4_cr_symbols1])dnl -m4_defn([m4_cr_digits])dnl -) - -# m4_cr_all -# --------- -# The character range representing everything, with `-' as the last -# character, since it is special to m4_translit. Use with care, because -# it contains characters special to M4 (fortunately, both ASCII and EBCDIC -# have [] in order, so m4_defn([m4_cr_all]) remains a valid string). It -# also contains characters special to terminals, so it should never be -# displayed in an error message. Also, attempts to map [ and ] to other -# characters via m4_translit must deal with the fact that m4_translit does -# not add quotes to the output. -# -# It is mainly useful in generating inverted character range maps, for use -# in places where m4_translit is faster than an equivalent m4_bpatsubst; -# the regex `[^a-z]' is equivalent to: -# m4_translit(m4_dquote(m4_defn([m4_cr_all])), [a-z]) -m4_define([m4_cr_all], -m4_translit(m4_dquote(m4_format(m4_dquote(m4_for( - ,1,255,,[[%c]]))m4_for([i],1,255,,[,i]))), [-])-) - - -# _m4_define_cr_not(CATEGORY) -# --------------------------- -# Define m4_cr_not_CATEGORY as the inverse of m4_cr_CATEGORY. -m4_define([_m4_define_cr_not], -[m4_define([m4_cr_not_$1], - m4_translit(m4_dquote(m4_defn([m4_cr_all])), - m4_defn([m4_cr_$1])))]) - - -# m4_cr_not_letters -# m4_cr_not_LETTERS -# m4_cr_not_Letters -# m4_cr_not_digits -# m4_cr_not_alnum -# m4_cr_not_symbols1 -# m4_cr_not_symbols2 -# ------------------ -# Inverse character sets -_m4_define_cr_not([letters]) -_m4_define_cr_not([LETTERS]) -_m4_define_cr_not([Letters]) -_m4_define_cr_not([digits]) -_m4_define_cr_not([alnum]) -_m4_define_cr_not([symbols1]) -_m4_define_cr_not([symbols2]) - - -# m4_newline -# ---------- -# Expands to a newline. Exists for formatting reasons. -m4_define([m4_newline], [ -]) - - -# m4_re_escape(STRING) -# -------------------- -# Escape RE active characters in STRING. -m4_define([m4_re_escape], -[m4_bpatsubst([$1], - [[][*+.?\^$]], [\\\&])]) - - -# m4_re_string -# ------------ -# Regexp for `[a-zA-Z_0-9]*' -# m4_dquote provides literal [] for the character class. -m4_define([m4_re_string], -m4_dquote(m4_defn([m4_cr_symbols2]))dnl -[*]dnl -) - - -# m4_re_word -# ---------- -# Regexp for `[a-zA-Z_][a-zA-Z_0-9]*' -m4_define([m4_re_word], -m4_dquote(m4_defn([m4_cr_symbols1]))dnl -m4_defn([m4_re_string])dnl -) - - -# m4_tolower(STRING) -# m4_toupper(STRING) -# ------------------ -# These macros convert STRING to lowercase or uppercase. -# -# Rather than expand the m4_defn each time, we inline them up front. -m4_define([m4_tolower], -[m4_translit([$1], ]m4_dquote(m4_defn([m4_cr_LETTERS]))[, - ]m4_dquote(m4_defn([m4_cr_letters]))[)]) -m4_define([m4_toupper], -[m4_translit([$1], ]m4_dquote(m4_defn([m4_cr_letters]))[, - ]m4_dquote(m4_defn([m4_cr_LETTERS]))[)]) - - -# m4_split(STRING, [REGEXP]) -# -------------------------- -# -# Split STRING into an m4 list of quoted elements. The elements are -# quoted with [ and ]. Beginning spaces and end spaces *are kept*. -# Use m4_strip to remove them. -# -# REGEXP specifies where to split. Default is [\t ]+. -# -# If STRING is empty, the result is an empty list. -# -# Pay attention to the m4_changequotes. When m4 reads the definition of -# m4_split, it still has quotes set to [ and ]. Luckily, these are matched -# in the macro body, so the definition is stored correctly. Use the same -# alternate quotes as m4_noquote; it must be unlikely to appear in $1. -# -# Also, notice that $1 is quoted twice, since we want the result to -# be quoted. Then you should understand that the argument of -# patsubst is -=<{(STRING)}>=- (i.e., with additional -=<{( and )}>=-). -# -# This macro is safe on active symbols, i.e.: -# m4_define(active, ACTIVE) -# m4_split([active active ])end -# => [active], [active], []end -# -# Optimize on regex of ` ' (space), since m4_foreach_w already guarantees -# that the list contains single space separators, and a common case is -# splitting a single-element list. This macro is called frequently, -# so avoid unnecessary dnl inside the definition. -m4_define([m4_split], -[m4_if([$1], [], [], - [$2], [ ], [m4_if(m4_index([$1], [ ]), [-1], [[[$1]]], [_$0($@)])], - [$2], [], [_$0([$1], [[ ]+])], - [_$0($@)])]) - -m4_define([_m4_split], -[m4_changequote([-=<{(],[)}>=-])]dnl -[[m4_bpatsubst(-=<{(-=<{($1)}>=-)}>=-, -=<{($2)}>=-, - -=<{(], [)}>=-)]m4_changequote([, ])]) - - - -# m4_flatten(STRING) -# ------------------ -# If STRING contains end of lines, replace them with spaces. If there -# are backslashed end of lines, remove them. This macro is safe with -# active symbols. -# m4_define(active, ACTIVE) -# m4_flatten([active -# act\ -# ive])end -# => active activeend -# -# In m4, m4_bpatsubst is expensive, so first check for a newline. -m4_define([m4_flatten], -[m4_if(m4_index([$1], [ -]), [-1], [[$1]], - [m4_translit(m4_bpatsubst([[[$1]]], [\\ -]), [ -], [ ])])]) - - -# m4_strip(STRING) -# ---------------- -# Expands into STRING with tabs and spaces singled out into a single -# space, and removing leading and trailing spaces. -# -# This macro is robust to active symbols. -# m4_define(active, ACTIVE) -# m4_strip([ active <tab> <tab>active ])end -# => active activeend -# -# First, notice that we guarantee trailing space. Why? Because regular -# expressions are greedy, and `.* ?' would always group the space into the -# .* portion. The algorithm is simpler by avoiding `?' at the end. The -# algorithm correctly strips everything if STRING is just ` '. -# -# Then notice the second pattern: it is in charge of removing the -# leading/trailing spaces. Why not just `[^ ]'? Because they are -# applied to over-quoted strings, i.e. more or less [STRING], due -# to the limitations of m4_bpatsubsts. So the leading space in STRING -# is the *second* character; equally for the trailing space. -m4_define([m4_strip], -[m4_bpatsubsts([$1 ], - [[ ]+], [ ], - [^. ?\(.*\) .$], [[[\1]]])]) - - -# m4_normalize(STRING) -# -------------------- -# Apply m4_flatten and m4_strip to STRING. -# -# The argument is quoted, so that the macro is robust to active symbols: -# -# m4_define(active, ACTIVE) -# m4_normalize([ act\ -# ive -# active ])end -# => active activeend - -m4_define([m4_normalize], -[m4_strip(m4_flatten([$1]))]) - - - -# m4_join(SEP, ARG1, ARG2...) -# --------------------------- -# Produce ARG1SEPARG2...SEPARGn. Avoid back-to-back SEP when a given ARG -# is the empty string. No expansion is performed on SEP or ARGs. -# -# Since the number of arguments to join can be arbitrarily long, we -# want to avoid having more than one $@ in the macro definition; -# otherwise, the expansion would require twice the memory of the already -# long list. Hence, m4_join merely looks for the first non-empty element, -# and outputs just that element; while _m4_join looks for all non-empty -# elements, and outputs them following a separator. The final trick to -# note is that we decide between recursing with $0 or _$0 based on the -# nested m4_if ending with `_'. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_join], -[m4_if([$#], [1], [], - [$#], [2], [[$2]], - [m4_if([$2], [], [], [[$2]_])$0([$1], m4_shift2($@))])]) -m4_define([_m4_join], -[m4_if([$#$2], [2], [], - [m4_if([$2], [], [], [[$1$2]])$0([$1], m4_shift2($@))])]) - -# m4_joinall(SEP, ARG1, ARG2...) -# ------------------------------ -# Produce ARG1SEPARG2...SEPARGn. An empty ARG results in back-to-back SEP. -# No expansion is performed on SEP or ARGs. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_joinall], [[$2]_$0([$1], m4_shift($@))]) -m4_define([_m4_joinall], -[m4_if([$#], [2], [], [[$1$3]$0([$1], m4_shift2($@))])]) - -# m4_combine([SEPARATOR], PREFIX-LIST, [INFIX], SUFFIX...) -# -------------------------------------------------------- -# Produce the pairwise combination of every element in the quoted, -# comma-separated PREFIX-LIST with every element from the SUFFIX arguments. -# Each pair is joined with INFIX, and pairs are separated by SEPARATOR. -# No expansion occurs on SEPARATOR, INFIX, or elements of either list. -# -# For example: -# m4_combine([, ], [[a], [b], [c]], [-], [1], [2], [3]) -# => a-1, a-2, a-3, b-1, b-2, b-3, c-1, c-2, c-3 -# -# In order to have the correct number of SEPARATORs, we use a temporary -# variable that redefines itself after the first use. We must use defn -# rather than overquoting in case PREFIX or SUFFIX contains $1, but use -# _m4_defn for speed. Likewise, we compute the m4_shift3 only once, -# rather than in each iteration of the outer m4_foreach. -m4_define([m4_combine], -[m4_if(m4_eval([$# > 3]), [1], - [m4_pushdef([m4_Separator], [m4_define([m4_Separator], - _m4_defn([m4_echo]))])]]dnl -[[m4_foreach([m4_Prefix], [$2], - [m4_foreach([m4_Suffix], ]m4_dquote(m4_dquote(m4_shift3($@)))[, - [m4_Separator([$1])[]_m4_defn([m4_Prefix])[$3]_m4_defn( - [m4_Suffix])])])]]dnl -[[_m4_popdef([m4_Separator])])]) - - -# m4_append(MACRO-NAME, STRING, [SEPARATOR]) -# ------------------------------------------ -# Redefine MACRO-NAME to hold its former content plus `SEPARATOR`'STRING' -# at the end. It is valid to use this macro with MACRO-NAME undefined, -# in which case no SEPARATOR is added. Be aware that the criterion is -# `not being defined', and not `not being empty'. -# -# Note that neither STRING nor SEPARATOR are expanded here; rather, when -# you expand MACRO-NAME, they will be expanded at that point in time. -# -# This macro is robust to active symbols. It can be used to grow -# strings. -# -# | m4_define(active, ACTIVE)dnl -# | m4_append([sentence], [This is an])dnl -# | m4_append([sentence], [ active ])dnl -# | m4_append([sentence], [symbol.])dnl -# | sentence -# | m4_undefine([active])dnl -# | sentence -# => This is an ACTIVE symbol. -# => This is an active symbol. -# -# It can be used to define hooks. -# -# | m4_define(active, ACTIVE)dnl -# | m4_append([hooks], [m4_define([act1], [act2])])dnl -# | m4_append([hooks], [m4_define([act2], [active])])dnl -# | m4_undefine([active])dnl -# | act1 -# | hooks -# | act1 -# => act1 -# => -# => active -# -# It can also be used to create lists, although this particular usage was -# broken prior to autoconf 2.62. -# | m4_append([list], [one], [, ])dnl -# | m4_append([list], [two], [, ])dnl -# | m4_append([list], [three], [, ])dnl -# | list -# | m4_dquote(list) -# => one, two, three -# => [one],[two],[three] -# -# Note that m4_append can benefit from amortized O(n) m4 behavior, if -# the underlying m4 implementation is smart enough to avoid copying existing -# contents when enlarging a macro's definition into any pre-allocated storage -# (m4 1.4.x unfortunately does not implement this optimization). We do -# not implement m4_prepend, since it is inherently O(n^2) (pre-allocated -# storage only occurs at the end of a macro, so the existing contents must -# always be moved). -# -# Use _m4_defn for speed. -m4_define([m4_append], -[m4_define([$1], m4_ifdef([$1], [_m4_defn([$1])[$3]])[$2])]) - - -# m4_append_uniq(MACRO-NAME, STRING, [SEPARATOR], [IF-UNIQ], [IF-DUP]) -# -------------------------------------------------------------------- -# Like `m4_append', but append only if not yet present. Additionally, -# expand IF-UNIQ if STRING was appended, or IF-DUP if STRING was already -# present. Also, warn if SEPARATOR is not empty and occurs within STRING, -# as the algorithm no longer guarantees uniqueness. -# -# Note that while m4_append can be O(n) (depending on the quality of the -# underlying M4 implementation), m4_append_uniq is inherently O(n^2) -# because each append operation searches the entire string. -m4_define([m4_append_uniq], -[m4_ifval([$3], [m4_if(m4_index([$2], [$3]), [-1], [], - [m4_warn([syntax], - [$0: `$2' contains `$3'])])])_$0($@)]) -m4_define([_m4_append_uniq], -[m4_ifdef([$1], - [m4_if(m4_index([$3]_m4_defn([$1])[$3], [$3$2$3]), [-1], - [m4_append([$1], [$2], [$3])$4], [$5])], - [m4_define([$1], [$2])$4])]) - -# m4_append_uniq_w(MACRO-NAME, STRINGS) -# ------------------------------------- -# For each of the words in the whitespace separated list STRINGS, append -# only the unique strings to the definition of MACRO-NAME. -# -# Use _m4_defn for speed. -m4_define([m4_append_uniq_w], -[m4_foreach_w([m4_Word], [$2], - [_m4_append_uniq([$1], _m4_defn([m4_Word]), [ ])])]) - - -# m4_text_wrap(STRING, [PREFIX], [FIRST-PREFIX], [WIDTH]) -# ------------------------------------------------------- -# Expands into STRING wrapped to hold in WIDTH columns (default = 79). -# If PREFIX is given, each line is prefixed with it. If FIRST-PREFIX is -# specified, then the first line is prefixed with it. As a special case, -# if the length of FIRST-PREFIX is greater than that of PREFIX, then -# FIRST-PREFIX will be left alone on the first line. -# -# No expansion occurs on the contents STRING, PREFIX, or FIRST-PREFIX, -# although quadrigraphs are correctly recognized. -# -# Typical outputs are: -# -# m4_text_wrap([Short string */], [ ], [/* ], 20) -# => /* Short string */ -# -# m4_text_wrap([Much longer string */], [ ], [/* ], 20) -# => /* Much longer -# => string */ -# -# m4_text_wrap([Short doc.], [ ], [ --short ], 30) -# => --short Short doc. -# -# m4_text_wrap([Short doc.], [ ], [ --too-wide ], 30) -# => --too-wide -# => Short doc. -# -# m4_text_wrap([Super long documentation.], [ ], [ --too-wide ], 30) -# => --too-wide -# => Super long -# => documentation. -# -# FIXME: there is no checking of a longer PREFIX than WIDTH, but do -# we really want to bother with people trying each single corner -# of a software? -# -# This macro does not leave a trailing space behind the last word of a line, -# which complicates it a bit. The algorithm is otherwise stupid and simple: -# all the words are preceded by m4_Separator which is defined to empty for -# the first word, and then ` ' (single space) for all the others. -# -# The algorithm uses a helper that uses $2 through $4 directly, rather than -# using local variables, to avoid m4_defn overhead, or expansion swallowing -# any $. It also bypasses m4_popdef overhead with _m4_popdef since no user -# macro expansion occurs in the meantime. Also, the definition is written -# with m4_do, to avoid time wasted on dnl during expansion (since this is -# already a time-consuming macro). -m4_define([m4_text_wrap], -[_$0([$1], [$2], m4_if([$3], [], [[$2]], [[$3]]), - m4_if([$4], [], [79], [[$4]]))]) -m4_define([_m4_text_wrap], -m4_do(dnl set up local variables, to avoid repeated calculations -[[m4_pushdef([m4_Indent], m4_qlen([$2]))]], -[[m4_pushdef([m4_Cursor], m4_qlen([$3]))]], -[[m4_pushdef([m4_Separator], [m4_define([m4_Separator], [ ])])]], -dnl expand the first prefix, then check its length vs. regular prefix -dnl same length: nothing special -dnl prefix1 longer: output on line by itself, and reset cursor -dnl prefix1 shorter: pad to length of prefix, and reset cursor -[[[$3]m4_cond([m4_Cursor], m4_Indent, [], - [m4_eval(m4_Cursor > m4_Indent)], [1], [ -[$2]m4_define([m4_Cursor], m4_Indent)], - [m4_format([%*s], m4_max([0], - m4_eval(m4_Indent - m4_Cursor)), [])m4_define([m4_Cursor], m4_Indent)])]], -dnl now, for each word, compute the curser after the word is output, then -dnl check if the cursor would exceed the wrap column -dnl if so, reset cursor, and insert newline and prefix -dnl if not, insert the separator (usually a space) -dnl either way, insert the word -[[m4_foreach_w([m4_Word], [$1], - [m4_define([m4_Cursor], - m4_eval(m4_Cursor + m4_qlen(_m4_defn([m4_Word])) - + 1))m4_if(m4_eval(m4_Cursor > ([$4])), - [1], [m4_define([m4_Cursor], - m4_eval(m4_Indent + m4_qlen(_m4_defn([m4_Word])) + 1)) -[$2]], - [m4_Separator[]])_m4_defn([m4_Word])])]], -dnl finally, clean up the local variabls -[[_m4_popdef([m4_Separator], [m4_Cursor], [m4_Indent])]])) - - -# m4_text_box(MESSAGE, [FRAME-CHARACTER = `-']) -# --------------------------------------------- -# Turn MESSAGE into: -# ## ------- ## -# ## MESSAGE ## -# ## ------- ## -# using FRAME-CHARACTER in the border. -m4_define([m4_text_box], -[m4_pushdef([m4_Border], - m4_translit(m4_format([%*s], m4_qlen(m4_expand([$1])), []), - [ ], m4_if([$2], [], [[-]], [[$2]])))dnl -@%:@@%:@ m4_Border @%:@@%:@ -@%:@@%:@ $1 @%:@@%:@ -@%:@@%:@ m4_Border @%:@@%:@_m4_popdef([m4_Border])dnl -]) - - -# m4_qlen(STRING) -# --------------- -# Expands to the length of STRING after autom4te converts all quadrigraphs. -# -# Avoid bpatsubsts for the common case of no quadrigraphs. -m4_define([m4_qlen], -[m4_if(m4_index([$1], [@]), [-1], [m4_len([$1])], - [m4_len(m4_bpatsubst([[$1]], - [@\(\(<:\|:>\|S|\|%:\|\{:\|:\}\)\(@\)\|&t@\)], - [\3]))])]) - - -# m4_qdelta(STRING) -# ----------------- -# Expands to the net change in the length of STRING from autom4te converting the -# quadrigraphs in STRING. This number is always negative or zero. -m4_define([m4_qdelta], -[m4_eval(m4_qlen([$1]) - m4_len([$1]))]) - - - -## ----------------------- ## -## 13. Number processing. ## -## ----------------------- ## - -# m4_cmp(A, B) -# ------------ -# Compare two integer expressions. -# A < B -> -1 -# A = B -> 0 -# A > B -> 1 -m4_define([m4_cmp], -[m4_eval((([$1]) > ([$2])) - (([$1]) < ([$2])))]) - - -# m4_list_cmp(A, B) -# ----------------- -# -# Compare the two lists of integer expressions A and B. For instance: -# m4_list_cmp([1, 0], [1]) -> 0 -# m4_list_cmp([1, 0], [1, 0]) -> 0 -# m4_list_cmp([1, 2], [1, 0]) -> 1 -# m4_list_cmp([1, 2, 3], [1, 2]) -> 1 -# m4_list_cmp([1, 2, -3], [1, 2]) -> -1 -# m4_list_cmp([1, 0], [1, 2]) -> -1 -# m4_list_cmp([1], [1, 2]) -> -1 -# m4_define([xa], [oops])dnl -# m4_list_cmp([[0xa]], [5+5]) -> 0 -# -# Rather than face the overhead of m4_case, we use a helper function whose -# expansion includes the name of the macro to invoke on the tail, either -# m4_ignore or m4_unquote. This is particularly useful when comparing -# long lists, since less text is being expanded for deciding when to end -# recursion. The recursion is between a pair of macros that alternate -# which list is trimmed by one element; this is more efficient than -# calling m4_cdr on both lists from a single macro. Guarantee exactly -# one expansion of both lists' side effects. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_list_cmp], -[_$0_raw(m4_dquote($1), m4_dquote($2))]) - -m4_define([_m4_list_cmp_raw], -[m4_if([$1], [$2], [0], [_m4_list_cmp_1([$1], $2)])]) - -m4_define([_m4_list_cmp], -[m4_if([$1], [], [0m4_ignore], [$2], [0], [m4_unquote], [$2m4_ignore])]) - -m4_define([_m4_list_cmp_1], -[_m4_list_cmp_2([$2], [m4_shift2($@)], $1)]) - -m4_define([_m4_list_cmp_2], -[_m4_list_cmp([$1$3], m4_cmp([$3+0], [$1+0]))( - [_m4_list_cmp_1(m4_dquote(m4_shift3($@)), $2)])]) - -# m4_max(EXPR, ...) -# m4_min(EXPR, ...) -# ----------------- -# Return the decimal value of the maximum (or minimum) in a series of -# integer expressions. -# -# M4 1.4.x doesn't provide ?:. Hence this huge m4_eval. Avoid m4_eval -# if both arguments are identical, but be aware of m4_max(0xa, 10) (hence -# the use of <=, not just <, in the second multiply). -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_max], -[m4_if([$#], [0], [m4_fatal([too few arguments to $0])], - [$#], [1], [m4_eval([$1])], - [$#$1], [2$2], [m4_eval([$1])], - [$#], [2], [_$0($@)], - [_m4_minmax([_$0], $@)])]) - -m4_define([_m4_max], -[m4_eval((([$1]) > ([$2])) * ([$1]) + (([$1]) <= ([$2])) * ([$2]))]) - -m4_define([m4_min], -[m4_if([$#], [0], [m4_fatal([too few arguments to $0])], - [$#], [1], [m4_eval([$1])], - [$#$1], [2$2], [m4_eval([$1])], - [$#], [2], [_$0($@)], - [_m4_minmax([_$0], $@)])]) - -m4_define([_m4_min], -[m4_eval((([$1]) < ([$2])) * ([$1]) + (([$1]) >= ([$2])) * ([$2]))]) - -# _m4_minmax(METHOD, ARG1, ARG2...) -# --------------------------------- -# Common recursion code for m4_max and m4_min. METHOD must be _m4_max -# or _m4_min, and there must be at least two arguments to combine. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([_m4_minmax], -[m4_if([$#], [3], [$1([$2], [$3])], - [$0([$1], $1([$2], [$3]), m4_shift3($@))])]) - - -# m4_sign(A) -# ---------- -# The sign of the integer expression A. -m4_define([m4_sign], -[m4_eval((([$1]) > 0) - (([$1]) < 0))]) - - - -## ------------------------ ## -## 14. Version processing. ## -## ------------------------ ## - - -# m4_version_unletter(VERSION) -# ---------------------------- -# Normalize beta version numbers with letters to numeric expressions, which -# can then be handed to m4_eval for the purpose of comparison. -# -# Nl -> (N+1).-1.(l#) -# -# for example: -# [2.14a] -> [2.14+1.-1.[0r36:a]] -> 2.15.-1.10 -# [2.14b] -> [2.15+1.-1.[0r36:b]] -> 2.15.-1.11 -# [2.61aa.b] -> [2.61+1.-1.[0r36:aa],+1.-1.[0r36:b]] -> 2.62.-1.370.1.-1.11 -# -# This macro expects reasonable version numbers, but can handle double -# letters and does not expand any macros. Original version strings can -# use both `.' and `-' separators. -# -# Inline constant expansions, to avoid m4_defn overhead. -# _m4_version_unletter is the real workhorse used by m4_version_compare, -# but since [0r36:a] is less readable than 10, we provide a wrapper for -# human use. -m4_define([m4_version_unletter], -[m4_map_sep([m4_eval], [.], - m4_dquote(m4_dquote_elt(m4_unquote(_$0([$1])))))]) -m4_define([_m4_version_unletter], -[m4_bpatsubst(m4_translit([[[$1]]], [.-], [,,]),]dnl -m4_dquote(m4_dquote(m4_defn([m4_cr_Letters])))[[+], - [+1,-1,[0r36:\&]])]) - - -# m4_version_compare(VERSION-1, VERSION-2) -# ---------------------------------------- -# Compare the two version numbers and expand into -# -1 if VERSION-1 < VERSION-2 -# 0 if = -# 1 if > -# -# Since _m4_version_unletter does not output side effects, we can -# safely bypass the overhead of m4_version_cmp. -m4_define([m4_version_compare], -[_m4_list_cmp_raw(_m4_version_unletter([$1]), _m4_version_unletter([$2]))]) - - -# m4_PACKAGE_NAME -# m4_PACKAGE_TARNAME -# m4_PACKAGE_VERSION -# m4_PACKAGE_STRING -# m4_PACKAGE_BUGREPORT -# -------------------- -# If m4sugar/version.m4 is present, then define version strings. This -# file is optional, provided by Autoconf but absent in Bison. -m4_sinclude([m4sugar/version.m4]) - - -# m4_version_prereq(VERSION, [IF-OK], [IF-NOT = FAIL]) -# ---------------------------------------------------- -# Check this Autoconf version against VERSION. -m4_define([m4_version_prereq], -m4_ifdef([m4_PACKAGE_VERSION], -[[m4_if(m4_version_compare(]m4_dquote(m4_defn([m4_PACKAGE_VERSION]))[, [$1]), - [-1], - [m4_default([$3], - [m4_fatal([Autoconf version $1 or higher is required], - [63])])], - [$2])]], -[[m4_fatal([m4sugar/version.m4 not found])]])) - - -## ------------------ ## -## 15. Set handling. ## -## ------------------ ## - -# Autoconf likes to create arbitrarily large sets; for example, as of -# this writing, the configure.ac for coreutils tracks a set of more -# than 400 AC_SUBST. How do we track all of these set members, -# without introducing duplicates? We could use m4_append_uniq, with -# the set NAME residing in the contents of the macro NAME. -# Unfortunately, m4_append_uniq is quadratic for set creation, because -# it costs O(n) to search the string for each of O(n) insertions; not -# to mention that with m4 1.4.x, even using m4_append is slow, costing -# O(n) rather than O(1) per insertion. Other set operations, not used -# by Autoconf but still possible by manipulation of the definition -# tracked in macro NAME, include O(n) deletion of one element and O(n) -# computation of set size. Because the set is exposed to the user via -# the definition of a single macro, we cannot cache any data about the -# set without risking the cache being invalidated by the user -# redefining NAME. -# -# Can we do better? Yes, because m4 gives us an O(1) search function -# for free: ifdef. Additionally, even m4 1.4.x gives us an O(1) -# insert operation for free: pushdef. But to use these, we must -# represent the set via a group of macros; to keep the set consistent, -# we must hide the set so that the user can only manipulate it through -# accessor macros. The contents of the set are maintained through two -# access points; _m4_set([name]) is a pushdef stack of values in the -# set, useful for O(n) traversal of the set contents; while the -# existence of _m4_set([name],value) with no particular value is -# useful for O(1) querying of set membership. And since the user -# cannot externally manipulate the set, we are free to add additional -# caching macros for other performance improvements. Deletion can be -# O(1) per element rather than O(n), by reworking the definition of -# _m4_set([name],value) to be 0 or 1 based on current membership, and -# adding _m4_set_cleanup(name) to defer the O(n) cleanup of -# _m4_set([name]) until we have another reason to do an O(n) -# traversal. The existence of _m4_set_cleanup(name) can then be used -# elsewhere to determine if we must dereference _m4_set([name],value), -# or assume that definition implies set membership. Finally, size can -# be tracked in an O(1) fashion with _m4_set_size(name). -# -# The quoting in _m4_set([name],value) is chosen so that there is no -# ambiguity with a set whose name contains a comma, and so that we can -# supply the value via _m4_defn([_m4_set([name])]) without needing any -# quote manipulation. - -# m4_set_add(SET, VALUE, [IF-UNIQ], [IF-DUP]) -# ------------------------------------------- -# Add VALUE as an element of SET. Expand IF-UNIQ on the first -# addition, and IF-DUP if it is already in the set. Addition of one -# element is O(1), such that overall set creation is O(n). -# -# We do not want to add a duplicate for a previously deleted but -# unpruned element, but it is just as easy to check existence directly -# as it is to query _m4_set_cleanup($1). -m4_define([m4_set_add], -[m4_ifdef([_m4_set([$1],$2)], - [m4_if(m4_indir([_m4_set([$1],$2)]), [0], - [m4_define([_m4_set([$1],$2)], - [1])_m4_set_size([$1], [m4_incr])$3], [$4])], - [m4_define([_m4_set([$1],$2)], - [1])m4_pushdef([_m4_set([$1])], - [$2])_m4_set_size([$1], [m4_incr])$3])]) - -# m4_set_add_all(SET, VALUE...) -# ----------------------------- -# Add each VALUE into SET. This is O(n) in the number of VALUEs, and -# can be faster than calling m4_set_add for each VALUE. -# -# Implement two recursion helpers; the check variant is slower but -# handles the case where an element has previously been removed but -# not pruned. The recursion helpers ignore their second argument, so -# that we can use the faster m4_shift2 and 2 arguments, rather than -# _m4_shift2 and one argument, as the signal to end recursion. -# -# Please keep foreach.m4 in sync with any adjustments made here. -m4_define([m4_set_add_all], -[m4_define([_m4_set_size($1)], m4_eval(m4_set_size([$1]) - + m4_len(m4_ifdef([_m4_set_cleanup($1)], [_$0_check], [_$0])([$1], $@))))]) - -m4_define([_m4_set_add_all], -[m4_if([$#], [2], [], - [m4_ifdef([_m4_set([$1],$3)], [], - [m4_define([_m4_set([$1],$3)], [1])m4_pushdef([_m4_set([$1])], - [$3])-])$0([$1], m4_shift2($@))])]) - -m4_define([_m4_set_add_all_check], -[m4_if([$#], [2], [], - [m4_set_add([$1], [$3])$0([$1], m4_shift2($@))])]) - -# m4_set_contains(SET, VALUE, [IF-PRESENT], [IF-ABSENT]) -# ------------------------------------------------------ -# Expand IF-PRESENT if SET contains VALUE, otherwise expand IF-ABSENT. -# This is always O(1). -m4_define([m4_set_contains], -[m4_ifdef([_m4_set_cleanup($1)], - [m4_if(m4_ifdef([_m4_set([$1],$2)], - [m4_indir([_m4_set([$1],$2)])], [0]), [1], [$3], [$4])], - [m4_ifdef([_m4_set([$1],$2)], [$3], [$4])])]) - -# m4_set_contents(SET, [SEP]) -# --------------------------- -# Expand to a single string containing all the elements in SET, -# separated by SEP, without modifying SET. No provision is made for -# disambiguating set elements that contain non-empty SEP as a -# sub-string, or for recognizing a set that contains only the empty -# string. Order of the output is not guaranteed. If any elements -# have been previously removed from the set, this action will prune -# the unused memory. This is O(n) in the size of the set before -# pruning. -# -# Use _m4_popdef for speed. The existence of _m4_set_cleanup($1) -# determines which version of _1 helper we use. -m4_define([m4_set_contents], -[m4_ifdef([_m4_set_cleanup($1)], [_$0_1c], [_$0_1])([$1])_$0_2([$1], - [_m4_defn([_m4_set_($1)])], [[$2]])]) - -# _m4_set_contents_1(SET) -# _m4_set_contents_1c(SET) -# _m4_set_contents_2(SET, SEP, PREP) -# ---------------------------------- -# Expand to a list of quoted elements currently in the set, separated -# by SEP, and moving PREP in front of SEP on recursion. To avoid -# nesting limit restrictions, the algorithm must be broken into two -# parts; _1 destructively copies the stack in reverse into -# _m4_set_($1), producing no output; then _2 destructively copies -# _m4_set_($1) back into the stack in reverse. SEP is expanded while -# _m4_set_($1) contains the current element, so a SEP containing -# _m4_defn([_m4_set_($1)]) can produce output in the order the set was -# created. Behavior is undefined if SEP tries to recursively list or -# modify SET in any way other than calling m4_set_remove on the -# current element. Use _1 if all entries in the stack are guaranteed -# to be in the set, and _1c to prune removed entries. Uses _m4_defn -# and _m4_popdef for speed. -m4_define([_m4_set_contents_1], -[m4_ifdef([_m4_set([$1])], [m4_pushdef([_m4_set_($1)], - _m4_defn([_m4_set([$1])]))_m4_popdef([_m4_set([$1])])$0([$1])])]) - -m4_define([_m4_set_contents_1c], -[m4_ifdef([_m4_set([$1])], - [m4_set_contains([$1], _m4_defn([_m4_set([$1])]), - [m4_pushdef([_m4_set_($1)], _m4_defn([_m4_set([$1])]))], - [_m4_popdef([_m4_set([$1],]_m4_defn( - [_m4_set([$1])])[)])])_m4_popdef([_m4_set([$1])])$0([$1])], - [_m4_popdef([_m4_set_cleanup($1)])])]) - -m4_define([_m4_set_contents_2], -[m4_ifdef([_m4_set_($1)], [m4_pushdef([_m4_set([$1])], - _m4_defn([_m4_set_($1)]))$2[]_m4_popdef([_m4_set_($1)])$0([$1], [$3$2])])]) - -# m4_set_delete(SET) -# ------------------ -# Delete all elements in SET, and reclaim any memory occupied by the -# set. This is O(n) in the set size. -# -# Use _m4_defn and _m4_popdef for speed. -m4_define([m4_set_delete], -[m4_ifdef([_m4_set([$1])], - [_m4_popdef([_m4_set([$1],]_m4_defn([_m4_set([$1])])[)], - [_m4_set([$1])])$0([$1])], - [m4_ifdef([_m4_set_cleanup($1)], - [_m4_popdef([_m4_set_cleanup($1)])])m4_ifdef( - [_m4_set_size($1)], - [_m4_popdef([_m4_set_size($1)])])])]) - -# m4_set_difference(SET1, SET2) -# ----------------------------- -# Produce a LIST of quoted elements that occur in SET1 but not SET2. -# Output a comma prior to any elements, to distinguish the empty -# string from no elements. This can be directly used as a series of -# arguments, such as for m4_join, or wrapped inside quotes for use in -# m4_foreach. Order of the output is not guaranteed. -# -# Short-circuit the idempotence relation. Use _m4_defn for speed. -m4_define([m4_set_difference], -[m4_if([$1], [$2], [], - [m4_set_foreach([$1], [_m4_element], - [m4_set_contains([$2], _m4_defn([_m4_element]), [], - [,_m4_defn([_m4_element])])])])]) - -# m4_set_dump(SET, [SEP]) -# ----------------------- -# Expand to a single string containing all the elements in SET, -# separated by SEP, then delete SET. In general, if you only need to -# list the contents once, this is faster than m4_set_contents. No -# provision is made for disambiguating set elements that contain -# non-empty SEP as a sub-string. Order of the output is not -# guaranteed. This is O(n) in the size of the set before pruning. -# -# Use _m4_popdef for speed. Use existence of _m4_set_cleanup($1) to -# decide if more expensive recursion is needed. -m4_define([m4_set_dump], -[m4_ifdef([_m4_set_size($1)], - [_m4_popdef([_m4_set_size($1)])])m4_ifdef([_m4_set_cleanup($1)], - [_$0_check], [_$0])([$1], [], [$2])]) - -# _m4_set_dump(SET, SEP, PREP) -# _m4_set_dump_check(SET, SEP, PREP) -# ---------------------------------- -# Print SEP and the current element, then delete the element and -# recurse with empty SEP changed to PREP. The check variant checks -# whether the element has been previously removed. Use _m4_defn and -# _m4_popdef for speed. -m4_define([_m4_set_dump], -[m4_ifdef([_m4_set([$1])], - [[$2]_m4_defn([_m4_set([$1])])_m4_popdef([_m4_set([$1],]_m4_defn( - [_m4_set([$1])])[)], [_m4_set([$1])])$0([$1], [$2$3])])]) - -m4_define([_m4_set_dump_check], -[m4_ifdef([_m4_set([$1])], - [m4_set_contains([$1], _m4_defn([_m4_set([$1])]), - [[$2]_m4_defn([_m4_set([$1])])])_m4_popdef( - [_m4_set([$1],]_m4_defn([_m4_set([$1])])[)], - [_m4_set([$1])])$0([$1], [$2$3])], - [_m4_popdef([_m4_set_cleanup($1)])])]) - -# m4_set_empty(SET, [IF-EMPTY], [IF-ELEMENTS]) -# -------------------------------------------- -# Expand IF-EMPTY if SET has no elements, otherwise IF-ELEMENTS. -m4_define([m4_set_empty], -[m4_ifdef([_m4_set_size($1)], - [m4_if(m4_indir([_m4_set_size($1)]), [0], [$2], [$3])], [$2])]) - -# m4_set_foreach(SET, VAR, ACTION) -# -------------------------------- -# For each element of SET, define VAR to the element and expand -# ACTION. ACTION should not recursively list SET's contents, add -# elements to SET, nor delete any element from SET except the one -# currently in VAR. The order that the elements are visited in is not -# guaranteed. This is faster than the corresponding m4_foreach([VAR], -# m4_indir([m4_dquote]m4_set_listc([SET])), [ACTION]) -m4_define([m4_set_foreach], -[m4_pushdef([$2])m4_ifdef([_m4_set_cleanup($1)], - [_m4_set_contents_1c], [_m4_set_contents_1])([$1])_m4_set_contents_2([$1], - [m4_define([$2], _m4_defn([_m4_set_($1)]))$3[]])m4_popdef([$2])]) - -# m4_set_intersection(SET1, SET2) -# ------------------------------- -# Produce a LIST of quoted elements that occur in both SET1 or SET2. -# Output a comma prior to any elements, to distinguish the empty -# string from no elements. This can be directly used as a series of -# arguments, such as for m4_join, or wrapped inside quotes for use in -# m4_foreach. Order of the output is not guaranteed. -# -# Iterate over the smaller set, and short-circuit the idempotence -# relation. Use _m4_defn for speed. -m4_define([m4_set_intersection], -[m4_if([$1], [$2], [m4_set_listc([$1])], - m4_eval(m4_set_size([$2]) < m4_set_size([$1])), [1], [$0([$2], [$1])], - [m4_set_foreach([$1], [_m4_element], - [m4_set_contains([$2], _m4_defn([_m4_element]), - [,_m4_defn([_m4_element])])])])]) - -# m4_set_list(SET) -# m4_set_listc(SET) -# ----------------- -# Produce a LIST of quoted elements of SET. This can be directly used -# as a series of arguments, such as for m4_join or m4_set_add_all, or -# wrapped inside quotes for use in m4_foreach or m4_map. With -# m4_set_list, there is no way to distinguish an empty set from a set -# containing only the empty string; with m4_set_listc, a leading comma -# is output if there are any elements. -m4_define([m4_set_list], -[m4_ifdef([_m4_set_cleanup($1)], [_m4_set_contents_1c], - [_m4_set_contents_1])([$1])_m4_set_contents_2([$1], - [_m4_defn([_m4_set_($1)])], [,])]) - -m4_define([m4_set_listc], -[m4_ifdef([_m4_set_cleanup($1)], [_m4_set_contents_1c], - [_m4_set_contents_1])([$1])_m4_set_contents_2([$1], - [,_m4_defn([_m4_set_($1)])])]) - -# m4_set_remove(SET, VALUE, [IF-PRESENT], [IF-ABSENT]) -# ---------------------------------------------------- -# If VALUE is an element of SET, delete it and expand IF-PRESENT. -# Otherwise expand IF-ABSENT. Deleting a single value is O(1), -# although it leaves memory occupied until the next O(n) traversal of -# the set which will compact the set. -# -# Optimize if the element being removed is the most recently added, -# since defining _m4_set_cleanup($1) slows down so many other macros. -# In particular, this plays well with m4_set_foreach. -m4_define([m4_set_remove], -[m4_set_contains([$1], [$2], [_m4_set_size([$1], - [m4_decr])m4_if(_m4_defn([_m4_set([$1])]), [$2], - [_m4_popdef([_m4_set([$1],$2)], [_m4_set([$1])])], - [m4_define([_m4_set_cleanup($1)])m4_define( - [_m4_set([$1],$2)], [0])])$3], [$4])]) - -# m4_set_size(SET) -# ---------------- -# Expand to the number of elements currently in SET. This operation -# is O(1), and thus more efficient than m4_count(m4_set_list([SET])). -m4_define([m4_set_size], -[m4_ifdef([_m4_set_size($1)], [m4_indir([_m4_set_size($1)])], [0])]) - -# _m4_set_size(SET, ACTION) -# ------------------------- -# ACTION must be either m4_incr or m4_decr, and the size of SET is -# changed accordingly. If the set is empty, ACTION must not be -# m4_decr. -m4_define([_m4_set_size], -[m4_define([_m4_set_size($1)], - m4_ifdef([_m4_set_size($1)], [$2(m4_indir([_m4_set_size($1)]))], - [1]))]) - -# m4_set_union(SET1, SET2) -# ------------------------ -# Produce a LIST of double quoted elements that occur in either SET1 -# or SET2, without duplicates. Output a comma prior to any elements, -# to distinguish the empty string from no elements. This can be -# directly used as a series of arguments, such as for m4_join, or -# wrapped inside quotes for use in m4_foreach. Order of the output is -# not guaranteed. -# -# We can rely on the fact that m4_set_listc prunes SET1, so we don't -# need to check _m4_set([$1],element) for 0. Use _m4_defn for speed. -# Short-circuit the idempotence relation. -m4_define([m4_set_union], -[m4_set_listc([$1])m4_if([$1], [$2], [], [m4_set_foreach([$2], [_m4_element], - [m4_ifdef([_m4_set([$1],]_m4_defn([_m4_element])[)], [], - [,_m4_defn([_m4_element])])])])]) - - -## ------------------- ## -## 16. File handling. ## -## ------------------- ## - - -# It is a real pity that M4 comes with no macros to bind a diversion -# to a file. So we have to deal without, which makes us a lot more -# fragile than we should. - - -# m4_file_append(FILE-NAME, CONTENT) -# ---------------------------------- -m4_define([m4_file_append], -[m4_syscmd([cat >>$1 <<_m4eof -$2 -_m4eof -]) -m4_if(m4_sysval, [0], [], - [m4_fatal([$0: cannot write: $1])])]) - - - -## ------------------------ ## -## 17. Setting M4sugar up. ## -## ------------------------ ## - - -# m4_init -# ------- -# Initialize the m4sugar language. -m4_define([m4_init], -[# All the M4sugar macros start with `m4_', except `dnl' kept as is -# for sake of simplicity. -m4_pattern_forbid([^_?m4_]) -m4_pattern_forbid([^dnl$]) - -# If __m4_version__ is defined, we assume that we are being run by M4 -# 1.6 or newer, and thus that $@ recursion is linear and debugmode(d) -# is available for faster checks of dereferencing undefined macros. -# But if it is missing, we assume we are being run by M4 1.4.x, that -# $@ recursion is quadratic, and that we need foreach-based -# replacement macros. Use the raw builtin to avoid tripping up -# include tracing. -m4_ifdef([__m4_version__], -[m4_debugmode([+d]) -m4_copy([_m4_defn], [m4_defn]) -m4_copy([_m4_popdef], [m4_popdef]) -m4_copy([_m4_undefine], [m4_undefine])], -[m4_builtin([include], [m4sugar/foreach.m4])]) - -# _m4_divert_diversion should be defined: -m4_divert_push([KILL]) - -# Check the divert push/pop perfect balance. -m4_wrap([m4_divert_pop([]) - m4_ifdef([_m4_divert_diversion], - [m4_fatal([$0: unbalanced m4_divert_push:]_m4_divert_n_stack)])[]]) -]) |