Index: doc/gdb.texinfo
===================================================================
RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v
retrieving revision 1.340
diff -u -p -r1.340 gdb.texinfo
--- doc/gdb.texinfo	21 Jun 2006 13:57:21 -0000	1.340
+++ doc/gdb.texinfo	7 Jul 2006 04:51:00 -0000
@@ -5033,6 +5033,23 @@ To add other directories, use the @code{
 The search path is used to find both program source files and @value{GDBN}
 script files (read using the @samp{-command} option and @samp{source} command).
 
+In addition to the source path, @value{GDBN} provides a set of commands
+that manage a source path substitution rule.  Instead of attempting to
+locate the source file using the original source path as described above,
+it will first apply the substitution rule to that source path, and use
+the resulting path instead.  By default, there is no substitution rule
+defined, but this can be very useful in the case when your source tree
+has been moved to a different location from the one where the sources
+were compiled. To define a source path substitution rule, use the
+@code{set substitute-path} command.
+
+Using the previous example, suppose the @file{foo-1.0} tree has been
+moved from @file{/usr/src} to @file{/mnt/cross}, then you can tell
+GDB to replace @file{/usr/src} in all source path names with
+@file{/mnt/cross}.  The first lookup will then be
+@file{/mnt/cross/foo-1.0/lib/foo.c} in place of the original location
+of @file{/usr/src/foo-1.0/lib/foo.c}.
+
 @table @code
 @item directory @var{dirname} @dots{}
 @item dir @var{dirname} @dots{}
@@ -5068,6 +5085,21 @@ Reset the source path to its default val
 @item show directories
 @kindex show directories
 Print the source path: show which directories it contains.
+
+@item set substitute-path @var{FROM} @var{TO}
+@kindex set substitute-path
+Define a source path substitution rule.  The new substitution rule
+replaces any rule previously defined.
+
+@item unset substitute-path
+@kindex unset substitute-path
+If a source path substitution rule is active, then cancel it.
+This command has no effect otherwise.
+
+@item show substitute-path
+@kindex show substitute-path
+Print the source path substitution rule if defined.
+
 @end table
 
 If your source path is cluttered with directories that are no longer of