m4sugar update

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Now that my copyright papers are complete, I rebased my m4sugar patches to
the current HEAD and verified that they allow operation with what will
become m4 1.6, whereas without the patch it failed.  Is it okay to commit
these three patches?  Once committed, I don't know of any show-stoppers
from the m4 side of things with releasing bison 2.4.

$ git fetch git://repo.or.cz/bison/ericb.git m4sugar

Eric Blake (3):
~      Fix comments in m4sugar.
~      Partial m4sugar merge from autoconf: builtins, version.m4.
~      Partial m4sugar merge from autoconf: m4_wrap vs. m4 1.6.

Still on my TODO list - figure out how to import the rest of m4sugar
improvements (it looks like there are some semantic changes in how m4_join
and m4_map are used that need adjusting before the testsuite will pass);
but those can be post 2.4 if I don't get them done soon.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

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>From a30e920d175dc87911322fc791a9f919ffa4cc82 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Wed, 16 Jul 2008 08:39:53 -0600
Subject: [PATCH] Fix comments in m4sugar.

* data/m4sugar/m4sugar.m4: Comment changes, borrowed from autoconf.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog               |    5 ++
 data/m4sugar/m4sugar.m4 |  155 +++++++++++++++++++++++++---------------------
 2 files changed, 89 insertions(+), 71 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a5df756..7c06eb0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-08-05  Eric Blake  <address@hidden>
+
+       Fix comments in m4sugar.
+       * data/m4sugar/m4sugar.m4: Comment changes, borrowed from autoconf.
+
 2008-08-02  Joel E. Denny  <address@hidden>
 
        Update for recent .gitignore fix in Gnulib.
diff --git a/data/m4sugar/m4sugar.m4 b/data/m4sugar/m4sugar.m4
index f3a0901..bc68ac2 100644
--- a/data/m4sugar/m4sugar.m4
+++ b/data/m4sugar/m4sugar.m4
@@ -3,8 +3,8 @@ divert(-1)#                                                  
-*- Autoconf -*-
 # Base M4 layer.
 # Requires GNU M4.
 #
-# Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005 Free Software
-# Foundation, Inc.
+# 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
@@ -88,28 +88,28 @@ m4_undefine([undefine])
 # 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 will certainly prefer to see `to'.
+# 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 as 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 as 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 as MACRO-NAME.
+# Copy m4_MACRO-NAME to MACRO-NAME.
 m4_define([m4_copy_unm4],
 [m4_copy([$1], m4_bpatsubst([$1], [^m4_\(.*\)], [[\1]]))])
 
@@ -210,6 +210,9 @@ m4_define([m4_assert],
 # 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], [])
 
 
@@ -219,7 +222,7 @@ m4_define([_m4_warn], [])
 m4_define([m4_warn],
 [_m4_warn([$1], [$2],
 m4_ifdef([m4_expansion_stack],
-         [m4_defn([m4_expansion_stack])
+        [m4_defn([m4_expansion_stack])
 m4_location[: the top level]]))dnl
 ])
 
@@ -232,8 +235,8 @@ m4_location[: the top level]]))dnl
 
 # 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
-# quite nobody quotes the first argument of m4_define.
+# 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])
@@ -253,7 +256,7 @@ m4_define([m4_include($1)])])
 
 # m4_include(FILE)
 # ----------------
-# As the builtin include, but warns against multiple inclusions.
+# Like the builtin include, but warns against multiple inclusions.
 m4_define([m4_include],
 [m4_include_unique([$1])dnl
 m4_builtin([include], [$1])])
@@ -261,7 +264,7 @@ m4_builtin([include], [$1])])
 
 # m4_sinclude(FILE)
 # -----------------
-# As the builtin sinclude, but warns against multiple inclusions.
+# Like the builtin sinclude, but warns against multiple inclusions.
 m4_define([m4_sinclude],
 [m4_include_unique([$1])dnl
 m4_builtin([sinclude], [$1])])
@@ -275,15 +278,15 @@ m4_builtin([sinclude], [$1])])
 # 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 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 a variation of `m4_ifset' that expects a macro name as $[1].
+# 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.
+# it runs TRUE, etc.
 
 
 # m4_ifval(COND, [IF-TRUE], [IF-FALSE])
@@ -529,9 +532,12 @@ m4_define([m4_dquote],  address@hidden)
 # m4_noquote(STRING)
 # ------------------
 # Return the result of ignoring all quotes in STRING and invoking the
-# macros it contains.  Amongst other things useful for enabling macro
-# invocations inside strings with [] blocks (for instance regexps and
-# help-strings).
+# 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([,])])
 
@@ -560,13 +566,14 @@ m4_builtin([undefine], $@)])
 
 
 ## -------------------------- ##
-## 7. Implementing m4 loops.  ##
+## 8. Implementing m4 loops.  ##
 ## -------------------------- ##
 
 
 # m4_for(VARIABLE, FIRST, LAST, [STEP = +/-1], EXPRESSION)
 # --------------------------------------------------------
-# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO.
+# Expand EXPRESSION defining VARIABLE to FROM, FROM + 1, ..., TO with
+# increments of STEP.
 # Both limits are included, and bounds are checked for consistency.
 m4_define([m4_for],
 [m4_case(m4_sign(m4_eval($3 - $2)),
@@ -589,21 +596,16 @@ m4_if($1, [$2], [],
 
 
 # Implementing `foreach' loops in m4 is much more tricky than it may
-# seem.  Actually, the example of a `foreach' loop in the m4
-# documentation is wrong: it does not quote the arguments properly,
-# which leads to undesirable expansions.
-#
-# The example in the documentation is:
+# 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_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],
-# |                                                        (shift$2),
-# |                                                        [$3])])])
+# |   [m4_if([$2], [()], ,
+# |     [m4_define([$1], _arg1$2)$3[]_foreach([$1], (m4_shift$2), [$3])])])
 #
 # But then if you run
 #
@@ -631,9 +633,7 @@ m4_if($1, [$2], [],
 # | m4_define([_arg1], [[$1]])
 # | m4_define([_foreach],
 # |  [m4_if($2, [()], ,
-# |         [m4_define([$1], [_arg1$2])$3[]_foreach([$1],
-# |                                                 [(shift$2)],
-# |                                                 [$3])])])
+# |    [m4_define([$1], [_arg1$2])$3[]_foreach([$1], [(m4_shift$2)], [$3])])])
 #
 # which this time answers
 #
@@ -656,14 +656,23 @@ m4_if($1, [$2], [],
 # | m4_define([_arg1], [$1])
 # | m4_define([_foreach],
 # |  [m4_if($2, [], ,
-# |         [m4_define([$1], [_arg1($2)])$3[]_foreach([$1],
-# |                                                   [shift($2)],
-# |                                                   [$3])])])
+# |    [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 quite satisfactory
-# implementation.
+# 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.
 
 
 # m4_foreach(VARIABLE, LIST, EXPRESSION)
@@ -710,7 +719,7 @@ m4_define([m4_foreach_w],
 
 
 ## --------------------------- ##
-## 8. More diversion support.  ##
+## 9. More diversion support.  ##
 ## --------------------------- ##
 
 
@@ -761,7 +770,7 @@ m4_builtin([divert], _m4_divert([$1]))dnl
 # 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_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
@@ -787,22 +796,23 @@ m4_divert_pop([$1])dnl
 
 # m4_divert_once(DIVERSION-NAME, CONTENT)
 # ---------------------------------------
-# Output once CONTENT into DIVERSION-NAME (which may be a number
-# actually).  An end of line is appended for free to 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.
+# 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]))])
 
 
-## -------------------------------------------- ##
-## 8. Defining macros with bells and whistles.  ##
-## -------------------------------------------- ##
+## --------------------------------------------- ##
+## 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
@@ -826,8 +836,8 @@ m4_define([m4_undivert],
 # the previous macros (by Axel Thimm).
 #
 #
-# The first idea: why using diversions?
-# -------------------------------------
+# 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
@@ -840,7 +850,7 @@ m4_define([m4_undivert],
 # | 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 level of m4_require separated.
+# 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
@@ -903,14 +913,14 @@ m4_define([m4_undivert],
 # i.e., TEST2a is expanded after TEST3 although the latter required the
 # former.
 #
-# Starting from 2.50, uses an implementation provided by Axel Thimm.
+# 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 macro are expanded.  (The bug above can
-# indeed be described as: a macro has been AC_PROVIDE'd, but it is
-# emitted after: the lack of correlation between emission and expansion
-# order is guilty).
+# 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 keeping the stack of diversions to elaborate the
+# 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
@@ -1182,25 +1192,26 @@ m4_define([$1],
 
 # m4_pattern_forbid(ERE, [WHY])
 # -----------------------------
-# Declare that no token matching the extended regular expression ERE
-# should be seen in the output but if...
+# 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)
 # ---------------------
-# ... but if that token matches the extended regular expression ERE.
+# ... that token also matches the allowed extended regular expression ERE.
 # Both used via traces.
 m4_define([m4_pattern_allow], [])
 
 
-## ----------------------------- ##
-## Dependencies between macros.  ##
-## ----------------------------- ##
+## --------------------------------- ##
+## 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])])])
@@ -1300,9 +1311,9 @@ m4_define([m4_provide_if],
          [$2], [$3])])
 
 
-## -------------------- ##
-## 9. Text processing.  ##
-## -------------------- ##
+## --------------------- ##
+## 12. Text processing.  ##
+## --------------------- ##
 
 
 # m4_cr_letters
@@ -1625,7 +1636,7 @@ m4_define([m4_qdelta],
 
 
 ## ----------------------- ##
-## 10. Number processing.  ##
+## 13. Number processing.  ##
 ## ----------------------- ##
 
 # m4_sign(A)
@@ -1640,8 +1651,7 @@ m4_define([m4_sign],
 
 # m4_cmp(A, B)
 # ------------
-#
-# Compare two integers.
+# Compare two integer expressions.
 # A < B -> -1
 # A = B ->  0
 # A > B ->  1
@@ -1672,7 +1682,7 @@ m4_define([m4_list_cmp],
 
 
 ## ------------------------ ##
-## 11. Version processing.  ##
+## 14. Version processing.  ##
 ## ------------------------ ##
 
 
@@ -1714,7 +1724,9 @@ m4_define([m4_version_compare],
 # m4_PACKAGE_STRING
 # m4_PACKAGE_BUGREPORT
 # --------------------
-#m4_include([m4sugar/version.m4]) # This is needed for Autoconf, but not Bison.
+# 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])
@@ -1731,13 +1743,13 @@ m4_define([m4_version_prereq],
 
 
 ## ------------------- ##
-## 12. File handling.  ##
+## 15. 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 that we should.
+# fragile than we should.
 
 
 # m4_file_append(FILE-NAME, CONTENT)
@@ -1753,12 +1765,13 @@ m4_if(m4_sysval, [0], [],
 
 
 ## ------------------------ ##
-## 13. Setting M4sugar up.  ##
+## 16. 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.
-- 
1.5.6.4


>From dfcc5959446a87785cad51a5c5fa7d0cca6b6373 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Wed, 16 Jul 2008 09:04:26 -0600
Subject: [PATCH] Partial m4sugar merge from autoconf: builtins, version.m4.

* data/m4sugar/m4sugar.m4 (changeword): Nuke.
(m4_prepend): Remove, as it is unused and inherently quadratic,
whereas m4_append is linear in newer m4.
(m4_mkstemp): New builtin.
(m4_symbols): Make rename conditional.
(m4_version_prereq): Ensure fatal error if used in bison, which
intentionally lacks version.m4.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog               |    9 +++++++++
 data/m4sugar/m4sugar.m4 |   41 +++++++++++++++++++++++------------------
 2 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 7c06eb0..f17e07f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2008-08-05  Eric Blake  <address@hidden>
 
+       Partial m4sugar merge from autoconf: builtins, version.m4.
+       * data/m4sugar/m4sugar.m4 (changeword): Nuke.
+       (m4_prepend): Remove, as it is unused and inherently quadratic,
+       whereas m4_append is linear in newer m4.
+       (m4_mkstemp): New builtin.
+       (m4_symbols): Make rename conditional.
+       (m4_version_prereq): Ensure fatal error if used in bison, which
+       intentionally lacks version.m4.
+
        Fix comments in m4sugar.
        * data/m4sugar/m4sugar.m4: Comment changes, borrowed from autoconf.
 
diff --git a/data/m4sugar/m4sugar.m4 b/data/m4sugar/m4sugar.m4
index bc68ac2..3ac4e00 100644
--- a/data/m4sugar/m4sugar.m4
+++ b/data/m4sugar/m4sugar.m4
@@ -115,10 +115,16 @@ m4_define([m4_copy_unm4],
 
 
 # Some m4 internals have names colliding with tokens we might use.
-# Rename them a` la `m4 --prefix-builtins'.
+# 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])
@@ -129,8 +135,6 @@ m4_rename_m4([errprint])
 m4_rename_m4([esyscmd])
 m4_rename_m4([eval])
 m4_rename_m4([format])
-m4_rename_m4([ifdef])
-m4_rename([ifelse], [m4_if])
 m4_undefine([include])
 m4_rename_m4([incr])
 m4_rename_m4([index])
@@ -138,7 +142,12 @@ m4_rename_m4([indir])
 m4_rename_m4([len])
 m4_rename([m4exit], [m4_exit])
 m4_rename([m4wrap], [m4_wrap])
-m4_rename_m4([maketemp])
+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_undefine([popdef])
 m4_rename_m4([pushdef])
@@ -146,7 +155,8 @@ m4_rename([regexp], [m4_bregexp])
 m4_rename_m4([shift])
 m4_undefine([sinclude])
 m4_rename_m4([substr])
-m4_rename_m4([symbols])
+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])
@@ -1524,13 +1534,6 @@ m4_define([m4_append],
 [m4_define([$1],
           m4_ifdef([$1], [m4_defn([$1])$3])[$2])])
 
-# m4_prepend(MACRO-NAME, STRING, [SEPARATOR])
-# -------------------------------------------
-# Same, but prepend.
-m4_define([m4_prepend],
-[m4_define([$1],
-          [$2]m4_ifdef([$1], [$3[]m4_defn([$1])]))])
-
 # m4_append_uniq(MACRO-NAME, STRING, [SEPARATOR])
 # -----------------------------------------------
 # As `m4_append', but append only if not yet present.
@@ -1733,12 +1736,14 @@ m4_sinclude([m4sugar/version.m4])
 # ----------------------------------------------------
 # Check this Autoconf version against VERSION.
 m4_define([m4_version_prereq],
-[m4_if(m4_version_compare(m4_defn([m4_PACKAGE_VERSION]), [$1]), -1,
-       [m4_default([$3],
-                  [m4_fatal([Autoconf version $1 or higher is required],
-                            63)])],
-       [$2])[]dnl
-])
+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])]]))
 
 
 
-- 
1.5.6.4


>From f989bf820715afe0ca768ddd56d8f119a096ff12 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Wed, 16 Jul 2008 12:47:48 -0600
Subject: [PATCH] Partial m4sugar merge from autoconf: m4_wrap vs. m4 1.6.

* data/m4sugar/m4sugar.m4 (m4_unquote, m4_wrap_lifo): New macros.
(m4_wrap): Guarantee FIFO order, in spite of m4 1.6.
(m4_init): Consolidate wrapped text into single m4_wrap.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog               |    5 +++++
 data/m4sugar/m4sugar.m4 |   46 +++++++++++++++++++++++++++++++++++++++++-----
 2 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f17e07f..8807725 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2008-08-05  Eric Blake  <address@hidden>
 
+       Partial m4sugar merge from autoconf: m4_wrap vs. m4 1.6.
+       * data/m4sugar/m4sugar.m4 (m4_unquote, m4_wrap_lifo): New macros.
+       (m4_wrap): Guarantee FIFO order, in spite of m4 1.6.
+       (m4_init): Consolidate wrapped text into single m4_wrap.
+
        Partial m4sugar merge from autoconf: builtins, version.m4.
        * data/m4sugar/m4sugar.m4 (changeword): Nuke.
        (m4_prepend): Remove, as it is unused and inherently quadratic,
diff --git a/data/m4sugar/m4sugar.m4 b/data/m4sugar/m4sugar.m4
index 3ac4e00..4fa54b3 100644
--- a/data/m4sugar/m4sugar.m4
+++ b/data/m4sugar/m4sugar.m4
@@ -141,7 +141,7 @@ m4_rename_m4([index])
 m4_rename_m4([indir])
 m4_rename_m4([len])
 m4_rename([m4exit], [m4_exit])
-m4_rename([m4wrap], [m4_wrap])
+m4_undefine([m4wrap])
 m4_ifdef([mkstemp],dnl added in M4 1.4.8
 [m4_rename_m4([mkstemp])
 m4_copy([m4_mkstemp], [m4_maketemp])
@@ -575,6 +575,41 @@ m4_define([m4_undefine],
 m4_builtin([undefine], $@)])
 
 
+# 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.
+m4_define([m4_unquote], [$*])
+
+# _m4_wrap(PRE, POST)
+# -------------------
+# Helper macro for m4_wrap and m4_wrap_lifo.  Allows nested calls to
+# m4_wrap within wrapped text.
+# Skip m4_defn and m4_popdef for speed.
+m4_define([_m4_wrap],
+[m4_ifdef([$0_text],
+         [m4_define([$0_text], [$1]m4_builtin([defn], [$0_text])[$2])],
+         [m4_builtin([m4wrap], [m4_unquote(m4_builtin([defn],
+  [$0_text])m4_builtin([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([$1[]])])
+
 ## -------------------------- ##
 ## 8. Implementing m4 loops.  ##
 ## -------------------------- ##
@@ -1783,10 +1818,11 @@ m4_define([m4_init],
 m4_pattern_forbid([^_?m4_])
 m4_pattern_forbid([^dnl$])
 
+# _m4_divert_diversion should be defined:
+m4_divert_push([KILL])
+
 # Check the divert push/pop perfect balance.
-m4_wrap([m4_ifdef([_m4_divert_diversion],
+m4_wrap([m4_divert_pop([])
+        m4_ifdef([_m4_divert_diversion],
           [m4_fatal([$0: unbalanced m4_divert_push:]_m4_divert_n_stack)])[]])
-
-m4_divert_push([KILL])
-m4_wrap([m4_divert_pop([KILL])[]])
 ])
-- 
1.5.6.4