-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
[adding autoconf-patches, replies can drop autoconf]
According to Eric Blake on 4/6/2009 8:25 PM:
> According to Mike Frysinger on 4/6/2009 3:43 PM:
> I'm also leaning towards omitting the else if $1 is provably blank,
> otherwise providing the : in case non-blank $1 ultimately expands to a
> blank (unless someone finds a shell where 'if false ; then :; fi; echo $?'
> fails to output 0). AS_CASE and AS_FOR are also candidates for this. And
> it will be easier with m4_ifblank. Stay tuned; I'll have a patch by the
> end of the week.
Here's what I'm about to apply.
- --
Don't work too hard, make some time for fun as well!
Eric Blake e...@byu.net
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org
iEYEARECAAYFAkneyqwACgkQ84KuGfSFAYA4xACeM27WusneT1UueEUy6khYtCCq
jDMAoNIacTpzZ+4wwaDXQrESVr6Ii7Z8
=yCfL
-----END PGP SIGNATURE-----
>From 709c9c86af078eefd4c44f3df3de52dda678794e Mon Sep 17 00:00:00 2001
From: Eric Blake <e...@byu.net>
Date: Thu, 9 Apr 2009 07:05:00 -0600
Subject: [PATCH 1/2] Add m4_blank and friends.
* lib/m4sugar/m4sugar.m4 (m4_blank, m4_nblank, m4_default_nblank)
(m4_default_nblank_quoted): New macros.
* NEWS: Document them.
* doc/autoconf.texi (Conditional constructs): Likewise.
* tests/m4sugar.at (m4sugar shorthand conditionals): New test.
Suggested by Mike Frysinger.
Signed-off-by: Eric Blake <e...@byu.net>
---
ChangeLog | 10 ++++++
NEWS | 3 ++
doc/autoconf.texi | 53 ++++++++++++++++++++++++++++-
lib/m4sugar/m4sugar.m4 | 47 +++++++++++++++++++++++---
tests/m4sugar.at | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 190 insertions(+), 8 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index be9ab98..4429431 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,15 @@
2009-04-09 Eric Blake <e...@byu.net>
+ Add m4_blank and friends.
+ * lib/m4sugar/m4sugar.m4 (m4_blank, m4_nblank, m4_default_nblank)
+ (m4_default_nblank_quoted): New macros.
+ * NEWS: Document them.
+ * doc/autoconf.texi (Conditional constructs): Likewise.
+ * tests/m4sugar.at (m4sugar shorthand conditionals): New test.
+ Suggested by Mike Frysinger.
+
+2009-04-09 Eric Blake <e...@byu.net>
+
Avoid problems caused by deleting in-use directory.
* lib/autotest/general.m4 (AT_INIT) <at_fn_group_prepare>: Only
remove the contents of $at_group_dir, not the directory itself.
diff --git a/NEWS b/NEWS
index e91fc39..0357cbd 100644
--- a/NEWS
+++ b/NEWS
@@ -7,6 +7,9 @@ GNU Autoconf NEWS - User visible changes.
proper m4 quoting. For shell comments, this is a new feature; for
non-shell comments, this fixes a regression introduced in 2.63b.
+** The following documented m4sugar macros are new:
+ m4_default_nblank m4_default_nblank_quoted m4_ifblank m4_ifnblank
+
* Major changes in Autoconf 2.63b (2009-03-31) [beta]
Released by Eric Blake, based on git versions 2.63.*.
diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 5e490fe..a47d3c8 100644
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -10987,25 +10987,74 @@ Conditional constructs
@defmac m4_default (@var{expr-1}, @var{expr-2})
@defmacx m4_default_quoted (@var{expr-1}, @var{expr-2})
+...@defmacx m4_default_nblank (@var{expr-1}, @ovar{expr-2})
+...@defmacx m4_default_nblank_quoted (@var{expr-1}, @ovar{expr-2})
@msindex{default}
@msindex{default_quoted}
-If @var{expr-1} is not empty, use it. Otherwise, select @var{expr-2}.
+...@msindex{default_nblank}
+...@msindex{default_nblank_quoted}
+If @var{expr-1} contains text, use it. Otherwise, select @var{expr-2}.
@code{m4_default} expands the result, while @code{m4_default_quoted}
does not. Useful for providing a fixed default if the expression that
-results in @var{expr-1} would otherwise be empty.
+results in @var{expr-1} would otherwise be empty. The difference
+between @code{m4_default} and @code{m4_default_nblank} is whether an
+argument consisting of just blanks (space, tab, newline) is
+significant. When using the expanding versions, note that an argument
+may contain text but still expand to an empty string.
@example
m4_define([active], [ACTIVE])dnl
+m4_define([empty], [])dnl
m4_define([demo1], [m4_default([$1], [$2])])dnl
m4_define([demo2], [m4_default_quoted([$1], [$2])])dnl
+m4_define([demo3], [m4_default_nblank([$1], [$2])])dnl
+m4_define([demo4], [m4_default_nblank_quoted([$1], [$2])])dnl
demo1([active], [default])
@result{}ACTIVE
demo1([], [active])
@result{}ACTIVE
+demo1([empty], [text])
+...@result{}
+-demo1([ ], [active])-
+...@result{}- -
demo2([active], [default])
@result{}active
demo2([], [active])
@result{}active
+demo2([empty], [text])
+...@result{}empty
+-demo2([ ], [active])-
+...@result{}- -
+demo3([active], [default])
+...@result{}active
+demo3([], [active])
+...@result{}active
+demo3([empty], [text])
+...@result{}
+-demo3([ ], [active])-
+...@result{}-active-
+demo4([active], [default])
+...@result{}active
+demo4([], [active])
+...@result{}active
+demo4([empty], [text])
+...@result{}empty
+-demo4([ ], [active])-
+...@result{}-active-
+...@end example
+...@end defmac
+
+...@defmac m4_ifblank (@var{cond}, @ovar{if-blank}, @ovar{if-text})
+...@defmacx m4_ifnblank (@var{cond}, @ovar{if-text}, @ovar{if-blank})
+...@msindex{ifblank}
+...@msindex{ifnblank}
+If @var{cond} is empty or consists only of blanks (space, tab, newline),
+then expand @var{if-blank}; otherwise, expand @var{if-text}. Two
+variants exist, in order to make it easier to select the correct logical
+sense when using only two parameters. Note that this is more efficient
+than the equivalent behavior of:
+...@example
+m4_ifval(m4_normalize([...@var{cond}]), @var{if-text}, @var{if-cond})
@end example
@end defmac
diff --git a/lib/m4sugar/m4sugar.m4 b/lib/m4sugar/m4sugar.m4
index 8356d08..420fd99 100644
--- a/lib/m4sugar/m4sugar.m4
+++ b/lib/m4sugar/m4sugar.m4
@@ -335,6 +335,29 @@ m4_builtin([sinclude], [$1])])
# it runs TRUE, etc.
+# m4_ifblank(COND, [IF-BLANK], [IF-TEXT])
+# m4_ifnblank(COND, [IF-TEXT], [IF-BLANK])
+# ----------------------------------------
+# If COND is empty, or consists only of blanks (space, tab, newline),
+# then expand IF-BLANK, otherwise expand IF-TEXT. This differs from
+# m4_ifval only if COND has just whitespace, but it helps optimize in
+# spite of users who mistakenly leave trailing space after what they
+# thought was an empty argument:
+# macro(
+# []
+# )
+#
+# Writing one macro in terms of the other causes extra overhead, so
+# we inline both definitions.
+m4_define([m4_ifblank],
+[m4_if(m4_translit([[$1]], [ ][ ][
+]), [], [$2], [$3])])
+
+m4_define([m4_ifnblank],
+[m4_if(m4_translit([[$1]], [ ][ ][
+]), [], [$3], [$2])])
+
+
# m4_ifval(COND, [IF-TRUE], [IF-FALSE])
# -------------------------------------
# If COND is not the empty string, expand IF-TRUE, otherwise IF-FALSE.
@@ -559,31 +582,43 @@ m4_define([m4_define_default],
# m4_default(EXP1, EXP2)
-# ----------------------
-# Returns EXP1 if non empty, otherwise EXP2. Expand the result.
+# m4_default_nblank(EXP1, EXP2)
+# -----------------------------
+# Returns EXP1 if not empty/blank, otherwise EXP2. Expand the result.
#
-# This macro is called on hot paths, so inline the contents of m4_ifval,
+# m4_default 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_define([m4_default_nblank],
+[m4_ifblank([$1], [$2], [$1])])
+
# m4_default_quoted(EXP1, EXP2)
-# -----------------------------
-# Returns EXP1 if non empty, otherwise EXP2. Leave the result quoted.
+# m4_default_nblank_quoted(EXP1, EXP2)
+# ------------------------------------
+# Returns EXP1 if non empty/blank, otherwise EXP2. Leave the result quoted.
#
# For comparison:
# m4_define([active], [ACTIVE])
# m4_default([active], [default]) => ACTIVE
# m4_default([], [active]) => ACTIVE
+# -m4_default([ ], [active])- => - -
+# -m4_default_nblank([ ], [active])- => -ACTIVE-
# m4_default_quoted([active], [default]) => active
# m4_default_quoted([], [active]) => active
+# -m4_default_quoted([ ], [active])- => - -
+# -m4_default_nblank_quoted([ ], [active])- => -active-
#
-# This macro is called on hot paths, so inline the contents of m4_ifval,
+# m4_default macro is called on hot paths, so inline the contents of m4_ifval,
# for one less round of expansion.
m4_define([m4_default_quoted],
[m4_if([$1], [], [[$2]], [[$1]])])
+m4_define([m4_default_nblank_quoted],
+[m4_ifblank([$1], [[$2]], [[$1]])])
+
# m4_defn(NAME)
# -------------
diff --git a/tests/m4sugar.at b/tests/m4sugar.at
index 6286af2..2dd81dc 100644
--- a/tests/m4sugar.at
+++ b/tests/m4sugar.at
@@ -649,6 +649,91 @@ m
AT_CLEANUP
+## ------------------------------------------------- ##
+## m4_ifval, m4_ifblank, m4_ifset, m4_default, etc. ##
+## ------------------------------------------------- ##
+
+AT_SETUP([m4sugar shorthand conditionals])
+AT_KEYWORDS([m4@&t...@_ifval m4@&t...@_ifblank m4@&t...@_ifnblank
m4@&t...@_ifset
+m4@&t...@_default m4@&t...@_default_quoted m4@&t...@_default_nblank
+m4@&t...@_default_nblank_quoted])
+
+AT_CHECK_M4SUGAR_TEXT([[m4_define([active], [ACTIVE])m4_define([empty])
+m4_ifval([active], [yes], [no])
+m4_ifval([empty], [yes], [no])
+m4_ifval([ ], [yes], [no])
+m4_ifval([], [yes], [no])
+m4_ifblank([active], [yes], [no])
+m4_ifblank([empty], [yes], [no])
+m4_ifblank([ ], [yes], [no])
+m4_ifblank([], [yes], [no])
+m4_ifnblank([active], [yes], [no])
+m4_ifnblank([empty], [yes], [no])
+m4_ifnblank([ ], [yes], [no])
+m4_ifnblank([], [yes], [no])
+m4_ifset([active], [yes], [no])
+m4_ifset([empty], [yes], [no])
+m4_ifset([ ], [yes], [no])
+m4_ifset([], [yes], [no])
+---
+m4_define([demo1], [m4_default([$1], [$2])])dnl
+m4_define([demo2], [m4_default_quoted([$1], [$2])])dnl
+m4_define([demo3], [m4_default_nblank([$1], [$2])])dnl
+m4_define([demo4], [m4_default_nblank_quoted([$1], [$2])])dnl
+demo1([active], [default])
+demo1([], [active])
+demo1([empty], [text])
+-demo1([ ], [active])-
+demo2([active], [default])
+demo2([], [active])
+demo2([empty], [text])
+-demo2([ ], [active])-
+demo3([active], [default])
+demo3([], [active])
+demo3([empty], [text])
+-demo3([ ], [active])-
+demo4([active], [default])
+demo4([], [active])
+demo4([empty], [text])
+-demo4([ ], [active])-
+]], [[
+yes
+yes
+yes
+no
+no
+no
+yes
+yes
+yes
+yes
+no
+no
+yes
+no
+no
+no
+---
+ACTIVE
+ACTIVE
+
+- -
+active
+active
+empty
+- -
+ACTIVE
+ACTIVE
+
+-ACTIVE-
+active
+active
+empty
+-active-
+]])
+
+AT_CLEANUP
+
## --------- ##
## m4_cond. ##
## --------- ##
--
1.6.1.2
>From 73b4250ff10680265b65215b5e72e41688f2308c Mon Sep 17 00:00:00 2001
From: Eric Blake <e...@byu.net>
Date: Thu, 9 Apr 2009 21:45:18 -0600
Subject: [PATCH 2/2] Make AS_IF, AS_CASE, and AS_FOR more robust to blank
arguments.
* lib/m4sugar/m4sh.m4 (_AS_CASE, _AS_CASE_DEFAULT, AS_FOR, _AS_IF)
(_AS_IF_ELSE, AS_IF): Avoid syntax error on blank argument.
* NEWS: Mention this.
* tests/m4sh.at (AS@&t...@_if and AS@&t...@_case, AS@&t...@_for): Update
tests.
Reported by Mike Frysinger.
Signed-off-by: Eric Blake <e...@byu.net>
---
ChangeLog | 8 ++++++++
NEWS | 3 +++
lib/m4sugar/m4sh.m4 | 29 ++++++++++++++++-------------
tests/m4sh.at | 11 ++++++++++-
4 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 4429431..071b418 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
2009-04-09 Eric Blake <e...@byu.net>
+ Make AS_IF, AS_CASE, and AS_FOR more robust to blank arguments.
+ * lib/m4sugar/m4sh.m4 (_AS_CASE, _AS_CASE_DEFAULT, AS_FOR, _AS_IF)
+ (_AS_IF_ELSE, AS_IF): Avoid syntax error on blank argument.
+ * NEWS: Mention this.
+ * tests/m4sh.at (AS@&t...@_if and AS@&t...@_case, AS@&t...@_for): Update
+ tests.
+ Reported by Mike Frysinger.
+
Add m4_blank and friends.
* lib/m4sugar/m4sugar.m4 (m4_blank, m4_nblank, m4_default_nblank)
(m4_default_nblank_quoted): New macros.
diff --git a/NEWS b/NEWS
index 0357cbd..8eb3a06 100644
--- a/NEWS
+++ b/NEWS
@@ -3,6 +3,9 @@ GNU Autoconf NEWS - User visible changes.
* Major changes in Autoconf 2.64 (2009-??-??) [stable]
Released by Eric Blake, based on git versions 2.63b.*.
+** AS_IF, AS_CASE, and AS_FOR have been taught to avoid syntax errors
+ even when given arguments that expand to just whitespace.
+
** Ensure AT_CHECK can support commands that include a # given with
proper m4 quoting. For shell comments, this is a new feature; for
non-shell comments, this fixes a regression introduced in 2.63b.
diff --git a/lib/m4sugar/m4sh.m4 b/lib/m4sugar/m4sh.m4
index 88881b1..b3dc63a 100644
--- a/lib/m4sugar/m4sh.m4
+++ b/lib/m4sugar/m4sh.m4
@@ -514,14 +514,16 @@ _AS_UNSET_PREPARE
# | esac
# The shell comments are intentional, to work around people who don't
# realize the impacts of using insufficient m4 quoting. This macro
-# always provides a default case, to work around a Solaris /bin/sh
-# bug regarding the exit status when no case matches.
+# always uses : and provides a default case, to work around Solaris
+# /bin/sh bugs regarding the exit status.
m4_define([_AS_CASE],
[ [...@%:@(]
- $1[)] m4_default([$2], [:]) ;;])
+ $1[)] :
+ $2 ;;])
m4_define([_AS_CASE_DEFAULT],
[ [...@%:@(]
- *[)] m4_default([$1], [:]) ;;])
+ *[)] :
+ $1 ;;])
m4_defun([AS_CASE],
[case $1 in[]m4_map_args_pair([_$0], [_$0_DEFAULT],
@@ -583,8 +585,8 @@ m4_defun([AS_FOR],
[m4_pushdef([$1], m4_if([$3], [], [[$$2]], m4_translit([$3], ]dnl
m4_dquote(_m4_defn([m4_cr_symbols2]))[[%+=:,./-]), [], [[$3]], [[$$2]]))]dnl
[for $2[]m4_ifval([$3], [ in $3])
-do
- m4_default([$4], [:])
+do :
+ $4
done[]_m4_popdef([$1])])
@@ -602,17 +604,18 @@ done[]_m4_popdef([$1])])
# with simplifications if IF-TRUE1 and/or IF-FALSE is empty.
#
m4_define([_AS_IF],
-[elif $1; then
- m4_default([$2], [:])
+[elif $1; then :
+ $2
])
m4_define([_AS_IF_ELSE],
-[m4_ifvaln([$1],
-[else
- $1])])
+[m4_ifnblank([$1],
+[else :
+ $1
+])])
m4_defun([AS_IF],
-[if $1; then
- m4_default([$2], [:])
+[if $1; then :
+ $2
m4_map_args_pair([_$0], [_$0_ELSE], m4_shift2($@))]dnl
[fi[]])# AS_IF
diff --git a/tests/m4sh.at b/tests/m4sh.at
index def63aa..fecb59a 100644
--- a/tests/m4sh.at
+++ b/tests/m4sh.at
@@ -859,6 +859,11 @@ rm -f file
AS_CASE([`touch file; false`]) && test -f file && echo fifteen
dnl The next line is badly underquoted; don't intentionally copy this style.
AS_CASE([foo], [foo], m4_do(AS_CASE([bar], [bar], [echo sixteen])))
+dnl Handle blank arguments.
+AS_IF([false], [:], [ ]) && AS_CASE([foo], [foo], []
+) && echo seventeen
+m4_define([empty])AS_IF([false], [:], [empty]
+) && AS_CASE([foo], [foo], [empty]) && echo eighteen
# check that require works correctly
m4_for([n], 1, 9, [],
@@ -911,6 +916,8 @@ thirteen
fourteen
fifteen
sixteen
+seventeen
+eighteen
foo1=1 bar1=1
foo2=2 bar2=
foo3=3 bar3=
@@ -979,13 +986,15 @@ AS_FOR([m4var], [shvar], ['$list'],
AS_FOR([m4var], [shvar], [\'],
[echo "m4var $shvar"])
-# Syntax checks: cope with empty arguments.
+# Syntax checks: cope with empty/blank arguments.
set f g
AS_FOR([], [shvar], [],
[echo "m4_defn([]) $shvar"])
rm -f file
AS_FOR([], [shvar], [`touch file`])
test -f file || exit 1
+AS_FOR([], [shvar], [], [ ])
+m4_define([empty])AS_FOR([], [shvar], [], [empty])
# Check that break works.
while :
--
1.6.1.2
