Recommend `sh -n' debugging, and public result variables for macros.

* doc/autoconf.texi (Debugging): Recommend to use "bash -n
configure".  Recommend the use of result variables as an
alternative to run-if-true/run-if-false parameters.

Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

diff --git a/ChangeLog b/ChangeLog
index 21a5a6e46abffee696a6b9bc40979b631163e93e..82d131c48e79e3c2128d448ad933af1cc13472ba 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-10-09  Bruno Haible  <bruno@clisp.org>
+           Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
+
+       Recommend `sh -n' debugging, and public result variables for macros.
+       * doc/autoconf.texi (Debugging): Recommend to use "bash -n
+       configure".  Recommend the use of result variables as an
+       alternative to run-if-true/run-if-false parameters.
+
 2009-10-05  Bruno Haible  <bruno@clisp.org>
 
        * doc/autoconf.texi (Particular Functions): Swap sections about

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index 6a31a21f275f28c62e287e5be9b3e771cc8d6d07..fd761502e02b85eb7d1708d04603ce41b3786623 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -24279,6 +24279,13 @@ possibility is to sprinkle pairs of @code{m4_traceon} and
 or listing some macro names and watch @command{m4} expand its input
 verbosely (@pxref{Debugging via autom4te}).
 
+@item
+Sometimes @command{autoconf} succeeds but the generated
+@command{configure} script has invalid shell syntax.  You can detect this
+case by running @samp{bash -n configure} or @samp{sh -n configure}.
+If this command fails, the same tips apply, as if @command{autoconf} had
+failed.
+
 @item
 Debugging @command{configure} script execution may be done by sprinkling
 pairs of @code{set -x} and @code{set +x} into the shell script before
@@ -24339,7 +24346,8 @@ tests,
 @item
 by not requiring users of your macro to use the cache variables.
 Instead, expose the result of the test via @var{run-if-true} and
-@var{run-if-false} parameters.
+@var{run-if-false} parameters.  If the result is not a boolean,
+then provide it through documented shell variables.
 @end itemize