Document that $srcdir can be used during configure.

* doc/autoconf.texi (Preset Output Variables): Add a paragraph.
* THANKS: Update.
Reported by Monty Taylor.

Signed-off-by: Eric Blake <ebb9@byu.net>

diff --git a/ChangeLog b/ChangeLog
index 26ddce08be160033e46a4f35c6797e8354dcd374..a2450bdea8876bb3684aa81496b74bf705cb1839 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2009-07-13  Eric Blake  <ebb9@byu.net>
+
+       Document that $srcdir can be used during configure.
+       * doc/autoconf.texi (Preset Output Variables): Add a paragraph.
+       * THANKS: Update.
+       Reported by Monty Taylor.
+
 2009-07-13  Eric Blake  <ebb9@byu.net>
 
        Disable asynchronous job notification for parallel tests.

diff --git a/THANKS b/THANKS
index 30f1b2d35db9c95521a2df5e8d32ccfb6c625d08..1c10fe438038bea173c8c1a7f6f32d89fe5b852c 100644 (file)
--- a/THANKS
+++ b/THANKS
@@ -257,6 +257,7 @@ Mikulas Patocka             ?
 Miles Bader                 miles@gnu.ai.mit.edu
 Mo DeJong                   mdejong@cygnus.com
 Momchil Velkov              velco@fadata.bg
+Monty Taylor                mordred@inaugust.com
 Morten Eriksen              mortene@sim.no
 Motoyuki Kasahara           m-kasahr@sra.co.jp
 Nathanael Nerode            neroden@gcc.gnu.org

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index cd2a65d5b501fbf1a3341f34eab43ca99c7bdae8..34df30b9c199cc3c70326e42f26aa5a0cd6aba74 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -2180,7 +2180,6 @@ is what the @command{configure} option @option{--srcdir} sets.
 The name of the top source directory, assuming that the working
 directory is the current build directory.
 
-
 @item ac_top_build_prefix
 The name of the top build directory, assuming that the working
 directory is the current build directory.
@@ -2332,6 +2331,15 @@ directories.  Below are listed the other preset ones, many of which are
 precious variables (@pxref{Setting Output Variables},
 @code{AC_ARG_VAR}).
 
+The preset variables which are available during @file{config.status}
+(@pxref{Configuration Actions}) may also be used during
+@command{configure} tests.  For example, it is permissible to reference
+@samp{$srcdir} when constructing a list of directories to pass via
+option @option{-I} during a compiler feature check.  When used in this
+manner, coupled with the fact that @command{configure} is always run
+from the top build directory, it is sufficient to use just
+@samp{$srcdir} instead of @samp{$top_srcdir}.
+
 @c Just say no to ASCII sorting!  We're humans, not computers.
 @c These variables are listed as they would be in a dictionary:
 @c actor