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Diffstat (limited to 'gnuwin32/bin/data/m4sugar/foreach.m4')
| -rw-r--r-- | gnuwin32/bin/data/m4sugar/foreach.m4 | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/gnuwin32/bin/data/m4sugar/foreach.m4 b/gnuwin32/bin/data/m4sugar/foreach.m4 new file mode 100644 index 00000000..f6a63944 --- /dev/null +++ b/gnuwin32/bin/data/m4sugar/foreach.m4 @@ -0,0 +1,362 @@ +# -*- Autoconf -*- +# This file is part of Autoconf. +# foreach-based replacements for recursive functions. +# Speeds up GNU M4 1.4.x by avoiding quadratic $@ recursion, but penalizes +# GNU M4 1.6 by requiring more memory and macro expansions. +# +# Copyright (C) 2008-2013 Free Software Foundation, Inc. + +# This file is part of Autoconf. 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. +# +# Under Section 7 of GPL version 3, you are granted additional +# permissions described in the Autoconf Configure Script Exception, +# version 3.0, as published by the Free Software Foundation. +# +# You should have received a copy of the GNU General Public License +# and a copy of the Autoconf Configure Script Exception along with +# this program; see the files COPYINGv3 and COPYING.EXCEPTION +# respectively. If not, see <http://www.gnu.org/licenses/>. + +# Written by Eric Blake. + +# In M4 1.4.x, every byte of $@ is rescanned. This means that an +# algorithm on n arguments that recurses with one less argument each +# iteration will scan n * (n + 1) / 2 arguments, for O(n^2) time. In +# M4 1.6, this was fixed so that $@ is only scanned once, then +# back-references are made to information stored about the scan. +# Thus, n iterations need only scan n arguments, for O(n) time. +# Additionally, in M4 1.4.x, recursive algorithms did not clean up +# memory very well, requiring O(n^2) memory rather than O(n) for n +# iterations. +# +# This file is designed to overcome the quadratic nature of $@ +# recursion by writing a variant of m4_foreach that uses m4_for rather +# than $@ recursion to operate on the list. This involves more macro +# expansions, but avoids the need to rescan a quadratic number of +# arguments, making these replacements very attractive for M4 1.4.x. +# On the other hand, in any version of M4, expanding additional macros +# costs additional time; therefore, in M4 1.6, where $@ recursion uses +# fewer macros, these replacements actually pessimize performance. +# Additionally, the use of $10 to mean the tenth argument violates +# POSIX; although all versions of m4 1.4.x support this meaning, a +# future m4 version may switch to take it as the first argument +# concatenated with a literal 0, so the implementations in this file +# are not future-proof. Thus, this file is conditionally included as +# part of m4_init(), only when it is detected that M4 probably has +# quadratic behavior (ie. it lacks the macro __m4_version__). +# +# Please keep this file in sync with m4sugar.m4. + +# _m4_foreach(PRE, POST, IGNORED, ARG...) +# --------------------------------------- +# Form the common basis of the m4_foreach and m4_map macros. For each +# ARG, expand PRE[ARG]POST[]. The IGNORED argument makes recursion +# easier, and must be supplied rather than implicit. +# +# This version minimizes the number of times that $@ is evaluated by +# using m4_for to generate a boilerplate into _m4_f then passing $@ to +# that temporary macro. Thus, the recursion is done in m4_for without +# reparsing any user input, and is not quadratic. For an idea of how +# this works, note that m4_foreach(i,[1,2],[i]) calls +# _m4_foreach([m4_define([i],],[)i],[],[1],[2]) +# which defines _m4_f: +# $1[$4]$2[]$1[$5]$2[]_m4_popdef([_m4_f]) +# then calls _m4_f([m4_define([i],],[)i],[],[1],[2]) for a net result: +# m4_define([i],[1])i[]m4_define([i],[2])i[]_m4_popdef([_m4_f]). +m4_define([_m4_foreach], +[m4_if([$#], [3], [], + [m4_pushdef([_m4_f], _m4_for([4], [$#], [1], + [$0_([1], [2],], [)])[_m4_popdef([_m4_f])])_m4_f($@)])]) + +m4_define([_m4_foreach_], +[[$$1[$$3]$$2[]]]) + +# m4_case(SWITCH, VAL1, IF-VAL1, VAL2, IF-VAL2, ..., DEFAULT) +# ----------------------------------------------------------- +# Find the first VAL that SWITCH matches, and expand the corresponding +# IF-VAL. If there are no matches, expand DEFAULT. +# +# Use m4_for to create a temporary macro in terms of a boilerplate +# m4_if with final cleanup. If $# is even, we have DEFAULT; if it is +# odd, then rounding the last $# up in the temporary macro is +# harmless. For example, both m4_case(1,2,3,4,5) and +# m4_case(1,2,3,4,5,6) result in the intermediate _m4_case being +# m4_if([$1],[$2],[$3],[$1],[$4],[$5],_m4_popdef([_m4_case])[$6]) +m4_define([m4_case], +[m4_if(m4_eval([$# <= 2]), [1], [$2], +[m4_pushdef([_$0], [m4_if(]_m4_for([2], m4_eval([($# - 1) / 2 * 2]), [2], + [_$0_(], [)])[_m4_popdef( + [_$0])]m4_dquote($m4_eval([($# + 1) & ~1]))[)])_$0($@)])]) + +m4_define([_m4_case_], +[$0_([1], [$1], m4_incr([$1]))]) + +m4_define([_m4_case__], +[[[$$1],[$$2],[$$3],]]) + +# m4_bmatch(SWITCH, RE1, VAL1, RE2, VAL2, ..., DEFAULT) +# ----------------------------------------------------- +# m4 equivalent of +# +# if (SWITCH =~ RE1) +# VAL1; +# elif (SWITCH =~ RE2) +# VAL2; +# elif ... +# ... +# else +# DEFAULT +# +# We build the temporary macro _m4_b: +# m4_define([_m4_b], _m4_defn([_m4_bmatch]))_m4_b([$1], [$2], [$3])... +# _m4_b([$1], [$m-1], [$m])_m4_b([], [], [$m+1]_m4_popdef([_m4_b])) +# then invoke m4_unquote(_m4_b($@)), for concatenation with later text. +m4_define([m4_bmatch], +[m4_if([$#], 0, [m4_fatal([$0: too few arguments: $#])], + [$#], 1, [m4_fatal([$0: too few arguments: $#: $1])], + [$#], 2, [$2], + [m4_pushdef([_m4_b], [m4_define([_m4_b], + _m4_defn([_$0]))]_m4_for([3], m4_eval([($# + 1) / 2 * 2 - 1]), + [2], [_$0_(], [)])[_m4_b([], [],]m4_dquote([$]m4_eval( + [($# + 1) / 2 * 2]))[_m4_popdef([_m4_b]))])m4_unquote(_m4_b($@))])]) + +m4_define([_m4_bmatch], +[m4_if(m4_bregexp([$1], [$2]), [-1], [], [[$3]m4_define([$0])])]) + +m4_define([_m4_bmatch_], +[$0_([1], m4_decr([$1]), [$1])]) + +m4_define([_m4_bmatch__], +[[_m4_b([$$1], [$$2], [$$3])]]) + + +# m4_cond(TEST1, VAL1, IF-VAL1, TEST2, VAL2, IF-VAL2, ..., [DEFAULT]) +# ------------------------------------------------------------------- +# Similar to m4_if, except that each TEST is expanded when encountered. +# If the expansion of TESTn matches the string VALn, the result is IF-VALn. +# The result is DEFAULT if no tests passed. This macro allows +# short-circuiting of expensive tests, where it pays to arrange quick +# filter tests to run first. +# +# m4_cond already guarantees either 3*n or 3*n + 1 arguments, 1 <= n. +# We only have to speed up _m4_cond, by building the temporary _m4_c: +# m4_define([_m4_c], _m4_defn([m4_unquote]))_m4_c([m4_if(($1), [($2)], +# [[$3]m4_define([_m4_c])])])_m4_c([m4_if(($4), [($5)], +# [[$6]m4_define([_m4_c])])])..._m4_c([m4_if(($m-2), [($m-1)], +# [[$m]m4_define([_m4_c])])])_m4_c([[$m+1]]_m4_popdef([_m4_c])) +# We invoke m4_unquote(_m4_c($@)), for concatenation with later text. +m4_define([_m4_cond], +[m4_pushdef([_m4_c], [m4_define([_m4_c], + _m4_defn([m4_unquote]))]_m4_for([2], m4_eval([$# / 3 * 3 - 1]), [3], + [$0_(], [)])[_m4_c(]m4_dquote(m4_dquote( + [$]m4_eval([$# / 3 * 3 + 1])))[_m4_popdef([_m4_c]))])m4_unquote(_m4_c($@))]) + +m4_define([_m4_cond_], +[$0_(m4_decr([$1]), [$1], m4_incr([$1]))]) + +m4_define([_m4_cond__], +[[_m4_c([m4_if(($$1), [($$2)], [[$$3]m4_define([_m4_c])])])]]) + +# m4_bpatsubsts(STRING, RE1, SUBST1, RE2, SUBST2, ...) +# ---------------------------------------------------- +# m4 equivalent of +# +# $_ = STRING; +# s/RE1/SUBST1/g; +# s/RE2/SUBST2/g; +# ... +# +# m4_bpatsubsts already validated an odd number of arguments; we only +# need to speed up _m4_bpatsubsts. To avoid nesting, we build the +# temporary _m4_p: +# m4_define([_m4_p], [$1])m4_define([_m4_p], +# m4_bpatsubst(m4_dquote(_m4_defn([_m4_p])), [$2], [$3]))m4_define([_m4_p], +# m4_bpatsubst(m4_dquote(_m4_defn([_m4_p])), [$4], [$5]))m4_define([_m4_p],... +# m4_bpatsubst(m4_dquote(_m4_defn([_m4_p])), [$m-1], [$m]))m4_unquote( +# _m4_defn([_m4_p])_m4_popdef([_m4_p])) +m4_define([_m4_bpatsubsts], +[m4_pushdef([_m4_p], [m4_define([_m4_p], + ]m4_dquote([$]1)[)]_m4_for([3], [$#], [2], [$0_(], + [)])[m4_unquote(_m4_defn([_m4_p])_m4_popdef([_m4_p]))])_m4_p($@)]) + +m4_define([_m4_bpatsubsts_], +[$0_(m4_decr([$1]), [$1])]) + +m4_define([_m4_bpatsubsts__], +[[m4_define([_m4_p], +m4_bpatsubst(m4_dquote(_m4_defn([_m4_p])), [$$1], [$$2]))]]) + +# m4_shiftn(N, ...) +# ----------------- +# Returns ... shifted N times. Useful for recursive "varargs" constructs. +# +# m4_shiftn already validated arguments; we only need to speed up +# _m4_shiftn. If N is 3, then we build the temporary _m4_s, defined as +# ,[$5],[$6],...,[$m]_m4_popdef([_m4_s]) +# before calling m4_shift(_m4_s($@)). +m4_define([_m4_shiftn], +[m4_if(m4_incr([$1]), [$#], [], [m4_pushdef([_m4_s], + _m4_for(m4_eval([$1 + 2]), [$#], [1], + [[,]m4_dquote($], [)])[_m4_popdef([_m4_s])])m4_shift(_m4_s($@))])]) + +# 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. +# +# Here, we use the temporary macro _m4_do, defined as +# $1[]$2[]...[]$n[]_m4_popdef([_m4_do]) +m4_define([m4_do], +[m4_if([$#], [0], [], + [m4_pushdef([_$0], _m4_for([1], [$#], [1], + [$], [[[]]])[_m4_popdef([_$0])])_$0($@)])]) + +# m4_dquote_elt(ARGS) +# ------------------- +# Return ARGS as an unquoted list of double-quoted arguments. +# +# _m4_foreach to the rescue. +m4_define([m4_dquote_elt], +[m4_if([$#], [0], [], [[[$1]]_m4_foreach([,m4_dquote(], [)], $@)])]) + +# m4_reverse(ARGS) +# ---------------- +# Output ARGS in reverse order. +# +# Invoke _m4_r($@) with the temporary _m4_r built as +# [$m], [$m-1], ..., [$2], [$1]_m4_popdef([_m4_r]) +m4_define([m4_reverse], +[m4_if([$#], [0], [], [$#], [1], [[$1]], +[m4_pushdef([_m4_r], [[$$#]]_m4_for(m4_decr([$#]), [1], [-1], + [[, ]m4_dquote($], [)])[_m4_popdef([_m4_r])])_m4_r($@)])]) + + +# m4_map_args_pair(EXPRESSION, [END-EXPR = EXPRESSION], ARG...) +# ------------------------------------------------------------- +# Perform a pairwise grouping of consecutive ARGs, by expanding +# EXPRESSION([ARG1], [ARG2]). If there are an odd number of ARGs, the +# final argument is expanded with END-EXPR([ARGn]). +# +# Build the temporary macro _m4_map_args_pair, with the $2([$m+1]) +# only output if $# is odd: +# $1([$3], [$4])[]$1([$5], [$6])[]...$1([$m-1], +# [$m])[]m4_default([$2], [$1])([$m+1])[]_m4_popdef([_m4_map_args_pair]) +m4_define([m4_map_args_pair], +[m4_if([$#], [0], [m4_fatal([$0: too few arguments: $#])], + [$#], [1], [m4_fatal([$0: too few arguments: $#: $1])], + [$#], [2], [], + [$#], [3], [m4_default([$2], [$1])([$3])[]], + [m4_pushdef([_$0], _m4_for([3], + m4_eval([$# / 2 * 2 - 1]), [2], [_$0_(], [)])_$0_end( + [1], [2], [$#])[_m4_popdef([_$0])])_$0($@)])]) + +m4_define([_m4_map_args_pair_], +[$0_([1], [$1], m4_incr([$1]))]) + +m4_define([_m4_map_args_pair__], +[[$$1([$$2], [$$3])[]]]) + +m4_define([_m4_map_args_pair_end], +[m4_if(m4_eval([$3 & 1]), [1], [[m4_default([$$2], [$$1])([$$3])[]]])]) + +# 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. +# +# Use a self-modifying separator, since we don't know how many +# arguments might be skipped before a separator is first printed, but +# be careful if the separator contains $. _m4_foreach to the rescue. +m4_define([m4_join], +[m4_pushdef([_m4_sep], [m4_define([_m4_sep], _m4_defn([m4_echo]))])]dnl +[_m4_foreach([_$0([$1],], [)], $@)_m4_popdef([_m4_sep])]) + +m4_define([_m4_join], +[m4_if([$2], [], [], [_m4_sep([$1])[$2]])]) + +# 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. +# +# A bit easier than m4_join. _m4_foreach to the rescue. +m4_define([m4_joinall], +[[$2]m4_if(m4_eval([$# <= 2]), [1], [], + [_m4_foreach([$1], [], m4_shift($@))])]) + +# m4_list_cmp(A, B) +# ----------------- +# Compare the two lists of integer expressions A and B. +# +# m4_list_cmp takes care of any side effects; we only override +# _m4_list_cmp_raw, where we can safely expand lists multiple times. +# First, insert padding so that both lists are the same length; the +# trailing +0 is necessary to handle a missing list. Next, create a +# temporary macro to perform pairwise comparisons until an inequality +# is found. For example, m4_list_cmp([1], [1,2]) creates _m4_cmp as +# m4_if(m4_eval([($1) != ($3)]), [1], [m4_cmp([$1], [$3])], +# m4_eval([($2) != ($4)]), [1], [m4_cmp([$2], [$4])], +# [0]_m4_popdef([_m4_cmp])) +# then calls _m4_cmp([1+0], [0*2], [1], [2+0]) +m4_define([_m4_list_cmp_raw], +[m4_if([$1], [$2], 0, + [_m4_list_cmp($1+0_m4_list_pad(m4_count($1), m4_count($2)), + $2+0_m4_list_pad(m4_count($2), m4_count($1)))])]) + +m4_define([_m4_list_pad], +[m4_if(m4_eval($1 < $2), [1], + [_m4_for(m4_incr([$1]), [$2], [1], [,0*])])]) + +m4_define([_m4_list_cmp], +[m4_pushdef([_m4_cmp], [m4_if(]_m4_for( + [1], m4_eval([$# >> 1]), [1], [$0_(], [,]m4_eval([$# >> 1])[)])[ + [0]_m4_popdef([_m4_cmp]))])_m4_cmp($@)]) + +m4_define([_m4_list_cmp_], +[$0_([$1], m4_eval([$1 + $2]))]) + +m4_define([_m4_list_cmp__], +[[m4_eval([($$1) != ($$2)]), [1], [m4_cmp([$$1], [$$2])], +]]) + +# m4_max(EXPR, ...) +# m4_min(EXPR, ...) +# ----------------- +# Return the decimal value of the maximum (or minimum) in a series of +# integer expressions. +# +# _m4_foreach to the rescue; we only need to replace _m4_minmax. Here, +# we need a temporary macro to track the best answer so far, so that +# the foreach expression is tractable. +m4_define([_m4_minmax], +[m4_pushdef([_m4_best], m4_eval([$2]))_m4_foreach( + [m4_define([_m4_best], $1(_m4_best,], [))], m4_shift($@))]dnl +[_m4_best[]_m4_popdef([_m4_best])]) + +# 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. +# +# _m4_foreach to the rescue. If no deletions have occurred, then +# avoid the speed penalty of m4_set_add. +m4_define([m4_set_add_all], +[m4_if([$#], [0], [], [$#], [1], [], + [m4_define([_m4_set_size($1)], m4_eval(m4_set_size([$1]) + + m4_len(_m4_foreach(m4_ifdef([_m4_set_cleanup($1)], + [[m4_set_add]], [[_$0]])[([$1],], [)], $@))))])]) + +m4_define([_m4_set_add_all], +[m4_ifdef([_m4_set([$1],$2)], [], + [m4_define([_m4_set([$1],$2)], + [1])m4_pushdef([_m4_set([$1])], [$2])-])]) |