Re: m4_cond [was: [RFA] autotest speedup]

[Eric Blake]

Eric Blake <ebb9 <at> byu.net> writes:

> As it is, m4sugar is woefully underdocumented in the manual.  So I added
> m4_cond and a couple others in the process.
> 
>       Provide better short-circuiting operation.
>       * lib/m4sugar/m4sugar.m4 (m4_cond, m4_newline): New macros.
>       (m4_text_wrap): Use it.  Also avoid useless m4_for.


> @@ -1696,15 +1739,14 @@ m4_pushdef([m4_Width], m4_default([$4], 79))dnl
> +     [m4_define([m4_Cursor], m4_len(m4_Prefix))[]dnl
> +m4_format(%m4_eval(m4_len(m4_Prefix) - 1 - m4_qlen(m4_defn([m4_Prefix1])))
[s],
> +       [])])[]dnl

Oops - this broke the latest m4 git checkout.  If m4_len(m4_Prefix) - 1 - 
m4_qlen(m4_defn([m4_Prefix1])) is exactly 0, this results in m4_format(%0s), 
and newer versions of m4 correctly warn (it would make m4 try to invoke the 
undefined printf("%0s")).  Also, I intend on making m4 1.4.11 warn if m4_format 
is called with too few arguments for the number of arguments designated by % 
specifiers (whereas it now silently uses 0 or "" for the missing arguments as 
appropriate).

Applying this, since m4_format([%*s],0,) is well-defined:

2007-10-08  Eric Blake  <address@hidden>

        Avoid m4 warnings on bad m4_format usage.
        * lib/m4sugar/m4sugar.m4 (m4_text_wrap): Use %*s, in case width
        evaulates to 0.
        * lib/autotest/general.m4 (AT_ordinal): Likewise; also ensure that
        enough arguments are provided.

---

From: Eric Blake <address@hidden>
Date: Mon, 8 Oct 2007 10:46:21 -0600
Subject: [PATCH] Avoid m4 warnings on bad m4_format usage.

* lib/m4sugar/m4sugar.m4 (m4_text_wrap): Use %*s, in case width
evaulates to 0.
* lib/autotest/general.m4 (AT_ordinal): Likewise; also ensure that
enough arguments are provided.

Signed-off-by: Eric Blake <address@hidden>
---
 ChangeLog               |   12 ++++++++++--
 lib/autotest/general.m4 |    4 ++--
 lib/m4sugar/m4sugar.m4  |    3 ++-
 3 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 159ba5b..6d613c1 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,7 +1,15 @@
+2007-10-08  Eric Blake  <address@hidden>
+
+       Avoid m4 warnings on bad m4_format usage.
+       * lib/m4sugar/m4sugar.m4 (m4_text_wrap): Use %*s, in case width
+       evaulates to 0.
+       * lib/autotest/general.m4 (AT_ordinal): Likewise; also ensure that
+       enough arguments are provided.
+
 2007-10-06  Paolo Bonzini  <address@hidden>
 
-        * doc/autoconf.texi (Shell portability): Document shell function
-        portability.
+       * doc/autoconf.texi (Shell portability): Document shell function
+       portability.
 
 2007-10-06  Paolo Bonzini  <address@hidden>
 
diff --git a/lib/autotest/general.m4 b/lib/autotest/general.m4
index df74838..707c7db 100644
--- a/lib/autotest/general.m4
+++ b/lib/autotest/general.m4
@@ -1257,8 +1257,8 @@ m4_divert_push([TESTS])dnl
   AT_ordinal ) @%:@ AT_ordinal. m4_defn([AT_line]): m4_defn([AT_description])
     at_setup_line='m4_defn([AT_line])'
     at_desc="AS_ESCAPE(m4_dquote(m4_defn([AT_description])))"
-    $at_quiet AS_ECHO_N(["m4_format([%3d: ], AT_ordinal)$at_desc"]dnl
-["m4_format(%m4_eval(47 - m4_qlen(m4_defn([AT_description])))[s])"])
+    $at_quiet AS_ECHO_N([m4_format(["%3d: $at_desc%*s"], AT_ordinal,
+      m4_eval(47 - m4_qlen(m4_defn([AT_description]))), [])])
 m4_divert_push([TEST_SCRIPT])dnl
 ])
 
diff --git a/lib/m4sugar/m4sugar.m4 b/lib/m4sugar/m4sugar.m4
index 1da5220..5385b3f 100644
--- a/lib/m4sugar/m4sugar.m4
+++ b/lib/m4sugar/m4sugar.m4
@@ -1745,7 +1745,8 @@ m4_Prefix],
        [m4_eval(m4_qlen(m4_defn([m4_Prefix1])) < m4_len(m4_Prefix))],
        [0], [],
        [m4_define([m4_Cursor], m4_len(m4_Prefix))[]dnl
-m4_format(%m4_eval(m4_len(m4_Prefix) - 1 - m4_qlen(m4_defn([m4_Prefix1])))[s],
+m4_format([%*s],
+         m4_eval(m4_len(m4_Prefix) - 1 - m4_qlen(m4_defn([m4_Prefix1]))),
          [])])[]dnl
 m4_foreach_w([m4_Word], [$1],
 [m4_define([m4_Cursor], m4_eval(m4_Cursor + m4_qlen(m4_defn([m4_Word])) + 1))
dnl
-- 
1.5.3.2