Re: more efficient AS_EXIT

[Eric Blake]

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According to Eric Blake on 10/25/2008 6:11 AM:
> I'll try to split it, then, and provide the _AS_REQUIRE_SHELL_FN
> factorization first (it is useful in its own right, whether or not we
> change AS_EXIT).

> I'll keep the patch updated, but we'll re-evaluate it after applying the
> non-controversial improvements.
>

Here's what I'm pushing for now.  Adding AS_SET_STATUS or changing AS_EXIT
to use a function are still on hold.

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

Eric Blake             address@hidden
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>From 489b6dac8c6c037499908e17171b2fcc75aa7512 Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 25 Oct 2008 06:26:49 -0600
Subject: [PATCH] Use AS_EXIT in autoconf.as.

* bin/autoconf.as: Consistently use AS_EXIT.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog       |    5 +++++
 bin/autoconf.as |    8 ++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 6be628c..70cc6fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-10-25  Eric Blake  <address@hidden>
+
+       Use AS_EXIT in autoconf.as.
+       * bin/autoconf.as: Consistently use AS_EXIT.
+
 2008-10-24  Eric Blake  <address@hidden>
 
        Fix m4 underquoting in AC_PROG_INSTALL.
diff --git a/bin/autoconf.as b/bin/autoconf.as
index 6eab32a..c678e55 100644
--- a/bin/autoconf.as
+++ b/bin/autoconf.as
@@ -81,7 +81,7 @@ Try \`$as_me --help' for more information."
 exit_missing_arg='
   AS_ECHO(["$as_me: option \`$[1]'\'' requires an argument"]) >&2
   AS_ECHO(["$help"]) >&2
-  exit 1
+  AS_EXIT([1])
 ' # restore font-lock: "
 
 # Variables.
@@ -156,7 +156,7 @@ while test $# -gt 0 ; do
        exec >&2
        AS_ECHO(["$as_me: invalid option $[1]"])
        AS_ECHO(["$help"])
-       exit 1 ;;
+       AS_EXIT([1]) ;;
     * )
        break ;;
   esac
@@ -175,7 +175,7 @@ case $# in
       infile=configure.in
     else
       AS_ECHO(["$as_me: no input file"]) >&2
-      exit 1
+      AS_EXIT([1])
     fi
     test -z "$traces" && test -z "$outfile" && outfile=configure;;
   1)
@@ -183,7 +183,7 @@ case $# in
   *) exec >&2
      AS_ECHO(["$as_me: invalid number of arguments."])
      AS_ECHO(["$help"])
-     (exit 1); exit 1 ;;
+     AS_EXIT([1]) ;;
 esac
 
 # Unless specified, the output is stdout.
-- 
1.6.0.2


>From 5d9dae38a348f4e9cc827bed1e97b6b5a522dcfa Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 25 Oct 2008 06:29:37 -0600
Subject: [PATCH] Document AS_EXIT.

* doc/autoconf.texi (Common Shell Constructs) <AS_EXIT>: Document
this macro.
(Limitations of Builtins): Mention AS_EXIT.
* NEWS: Mention it.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog         |    6 ++++++
 NEWS              |    6 +++---
 doc/autoconf.texi |   11 ++++++++++-
 3 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 70cc6fc..a0f87ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2008-10-25  Eric Blake  <address@hidden>
 
+       Document AS_EXIT.
+       * doc/autoconf.texi (Common Shell Constructs) <AS_EXIT>: Document
+       this macro.
+       (Limitations of Builtins): Mention AS_EXIT.
+       * NEWS: Mention it.
+
        Use AS_EXIT in autoconf.as.
        * bin/autoconf.as: Consistently use AS_EXIT.
 
diff --git a/NEWS b/NEWS
index 496fac7..5bdff48 100644
--- a/NEWS
+++ b/NEWS
@@ -23,9 +23,9 @@ GNU Autoconf NEWS - User visible changes.
    AS_LINENO_PREPARE  AS_ME_PREPARE  AS_VAR_APPEND  AS_VAR_COPY
 
 ** The following m4sh macros are documented now:
-   AS_ECHO  AS_ECHO_N  AS_LITERAL_IF  AS_UNSET  AS_VAR_IF  AS_VAR_POPDEF
-   AS_VAR_PUSHDEF  AS_VAR_SET  AS_VAR_SET_IF  AS_VAR_TEST_SET
-   AS_VERSION_COMPARE
+   AS_ECHO  AS_ECHO_N  AS_EXIT  AS_LITERAL_IF  AS_UNSET  AS_VAR_IF
+   AS_VAR_POPDEF  AS_VAR_PUSHDEF  AS_VAR_SET  AS_VAR_SET_IF
+   AS_VAR_TEST_SET  AS_VERSION_COMPARE
 
 ** The m4sh macros AS_IF and AS_CASE can now be used in shell lists.
    The responsibility for supplying a trailing newline now belongs to
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 8509322..b89ce5b 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -11966,6 +11966,14 @@ Common Shell Constructs
 Redirections can be placed outside the macro invocation.
 @end defmac
 
address@hidden AS_EXIT (@dvar{status, 1})
address@hidden
+Emit code to exit the shell with @var{status}.  This works around shells
+that see the exit status of the command prior to @code{exit} inside a
address@hidden 0} handler (@pxref{Limitations of Builtins, , Limitations of
+Shell Builtins}).
address@hidden defmac
+
 @defmac AS_IF (@var{test1}, @ovar{run-if-true1}, @dots{}, @ovar{run-if-false})
 @asindex{IF}
 Run shell code @var{test1}.  If @var{test1} exits with a zero status then
@@ -15433,7 +15441,8 @@ Limitations of Builtins
 The portable solution is then simple: when you want to @samp{exit 42},
 run @samp{(exit 42); exit 42}, the first @command{exit} being used to
 set the exit status to 42 for Zsh, and the second to trigger the trap
-and pass 42 as exit status for Bash.
+and pass 42 as exit status for Bash.  In m4sh, this is covered by using
address@hidden
 
 The shell in address@hidden 4.0 has the following bug: @samp{$?} is
 reset to 0 by empty lines if the code is inside @command{trap}.
-- 
1.6.0.2


>From ce2d0f043cbe77a78fb1d0e2427543cf8cb9c9ca Mon Sep 17 00:00:00 2001
From: Eric Blake <address@hidden>
Date: Sat, 25 Oct 2008 06:37:43 -0600
Subject: [PATCH] Simplify _AS_PREPARE handling of functions.

* lib/m4sugar/m4sh.m4 (AS_REQUIRE_SHELL_FN): Factor...
(_AS_REQUIRE_SHELL_FN): ...into new helper macro.
(_AS_PREPARE): Temporarily redefine AS_REQUIRE_SHELL_FN to make
this task easier.
(_AS_LINENO_PREPARE): Make more efficient.
(_AS_MKDIR_P_PREPARE): Simplify use in _AS_PREPARE.
(_AS_UNSET_PREPARE): Avoid blank newline.
(AS_INIT): Emit as_func_unset alongside other functions.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog           |   12 ++++++++++++
 lib/m4sugar/m4sh.m4 |   49 +++++++++++++++++++++++++------------------------
 2 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a0f87ec..dab6a6e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,17 @@
 2008-10-25  Eric Blake  <address@hidden>
 
+       Simplify _AS_PREPARE handling of functions.
+       * lib/m4sugar/m4sh.m4 (AS_REQUIRE_SHELL_FN): Factor...
+       (_AS_REQUIRE_SHELL_FN): ...into new helper macro.
+       (_AS_PREPARE): Temporarily redefine AS_REQUIRE_SHELL_FN to make
+       this task easier.
+       (_AS_LINENO_PREPARE): Make more efficient.
+       (_AS_MKDIR_P_PREPARE): Simplify use in _AS_PREPARE.
+       (_AS_UNSET_PREPARE): Avoid blank newline.
+       (AS_INIT): Emit as_func_unset alongside other functions.
+
+2008-10-25  Eric Blake  <address@hidden>
+
        Document AS_EXIT.
        * doc/autoconf.texi (Common Shell Constructs) <AS_EXIT>: Document
        this macro.
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 6620a56..6124065 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -255,17 +255,17 @@ fi
 # and config.status.  Relying on AS_REQUIRE is of course fine for
 # configure, but fails for config.status (which is created by
 # configure).  So we need a means to force the inclusion of the
-# various _AS_PREPARE_* on top of config.status.  That's basically why
-# there are so many _AS_PREPARE_* below, and that's also why it is
+# various _AS_*_PREPARE on top of config.status.  That's basically why
+# there are so many _AS_*_PREPARE below, and that's also why it is
 # important not to forget some: config.status needs them.
+# List any preparations that create shell functions first, then
+# topologically sort the others by their dependencies.
 m4_defun([_AS_PREPARE],
-[m4_pushdef([AS_REQUIRE], [])]dnl
-[AS_FUNCTION_DESCRIBE([as_func_mkdir_p], [],
-[Create "$as_dir" as a directory, including parents if necessary.])
-as_func_mkdir_p ()
-{
-  _AS_MKDIR_P
-}
+[m4_pushdef([AS_REQUIRE])]dnl
+[m4_pushdef([AS_REQUIRE_SHELL_FN], _m4_defn([_AS_REQUIRE_SHELL_FN])
+)]dnl
+[_AS_UNSET_PREPARE
+_AS_VAR_APPEND_PREPARE
 
 _AS_EXPR_PREPARE
 _AS_BASENAME_PREPARE
@@ -278,9 +278,7 @@ _AS_MKDIR_P_PREPARE
 _AS_TEST_PREPARE
 _AS_TR_CPP_PREPARE
 _AS_TR_SH_PREPARE
-_AS_UNSET_PREPARE
-_AS_VAR_APPEND_PREPARE
-m4_popdef([AS_REQUIRE])])
+_m4_popdef([AS_REQUIRE], [AS_REQUIRE_SHELL_FN])])
 
 # AS_PREPARE
 # ----------
@@ -325,6 +323,14 @@ m4_defun([AS_REQUIRE],
        1, [m4_require(],
          [m4_divert_require(_m4_divert(_m4_divert_desired),]) [$1], [$2])])
 
+# _AS_REQUIRE_SHELL_FN(NAME-TO-CHECK, COMMENT, BODY-TO-EXPAND)
+# ------------------------------------------------------------
+# Core of AS_REQUIRE_SHELL_FN, but without diversion support.
+m4_define([_AS_REQUIRE_SHELL_FN], [
+m4_n([$2])$1 ()
+{
+$3
+} @%:@ $1[]])
 
 # AS_REQUIRE_SHELL_FN(NAME-TO-CHECK, COMMENT, BODY-TO-EXPAND,
 #                     [DIVERSION = M4SH-INIT-FN])
@@ -337,12 +343,8 @@ m4_defun([AS_REQUIRE],
 m4_define([AS_REQUIRE_SHELL_FN],
 [m4_provide_if([AS_SHELL_FN_$1], [],
 [AS_REQUIRE([AS_SHELL_FN_$1],
-[m4_provide([AS_SHELL_FN_$1])
-m4_n([$2])$1 ()
-{
-$3
-} [#] $1
-], m4_default_quoted([$4], [M4SH-INIT-FN]))])])
+[m4_provide([AS_SHELL_FN_$1])_$0($@)],
+m4_default_quoted([$4], [M4SH-INIT-FN]))])])
 
 
 # _AS_RUN(TEST, [SHELL])
@@ -555,8 +557,7 @@ as_func_unset ()
 {
   AS_UNSET([$[1]])
 }
-as_unset=as_func_unset
-])
+as_unset=as_func_unset])
 
 
 # AS_UNSET(VAR)
@@ -1001,7 +1002,7 @@ dnl Eggert wrote the scripts with optimization help from 
Paolo Bonzini).
   # Exit status is that of the last command.
   exit
 }
-m4_popdef([AS_MESSAGE_LOG_FD])])# _AS_LINENO_PREPARE
+_m4_popdef([AS_MESSAGE_LOG_FD])])# _AS_LINENO_PREPARE
 
 
 # _AS_LN_S_PREPARE
@@ -1090,8 +1091,8 @@ m4_defun([_AS_MKDIR_P_PREPARE],
     [Create "$as_dir" as a directory, including parents if necessary.])],
 [
   _AS_MKDIR_P
-])
-if mkdir -p . 2>/dev/null; then
+])]dnl
+[if mkdir -p . 2>/dev/null; then
   as_mkdir_p='mkdir -p "$as_dir"'
 else
   test -d ./-p && rmdir ./-p
@@ -1818,5 +1819,5 @@ m4_divert_pop([KILL])[]dnl
 m4_divert_push([BODY])
 m4_text_box([Main body of script.])
 _AS_DETECT_REQUIRED([_AS_SHELL_FN_WORK])dnl
-AS_REQUIRE([_AS_UNSET_PREPARE])dnl For backwards compatibility.
+AS_REQUIRE([_AS_UNSET_PREPARE], [], [M4SH-INIT-FN])dnl
 ])
-- 
1.6.0.2