(Programming in M4sh): Add AS_MKDIR_P.

(Limitations of Usual Tools): Add mkdir section.

diff --git a/doc/autoconf.texi b/doc/autoconf.texi
index abae42a5253881535c0bba3bbbcf91c3c1c70c17..90c9db4c501e60ff2f3635a73ac17c7724f54fd7 100644 (file)
--- a/doc/autoconf.texi
+++ b/doc/autoconf.texi
@@ -7419,6 +7419,13 @@ details about what this returns and why it is more portable than the
 @command{dirname} command.
 @end defmac
 
+@defmac AS_MKDIR_P (@var{filename})
+@msindex MKDIR_P
+Make the directory @var{filename}, including intervening directories
+as necessary.  This is equivalent to @samp{mkdir -p @var{filename}},
+except that it is portable to older versions of @command{mkdir} that
+lack support for the @option{-p} option.
+
 @c=================================================== Writing Autoconf Macros.
 
 @node Writing Autoconf Macros
@@ -9707,6 +9714,15 @@ works for executables, so @samp{cp -p} is used instead for these
 systems.  DJGPP versions 2.04 and later have full symlink support.
 
 
+@item @command{mkdir}
+@c ------------------
+@prindex @command{mkdir}
+@cindex Making directories
+None of @command{mkdir}'s options are portable.  Instead of
+@samp{mkdir -p @var{filename}}, you should use use
+@code{AS_MKDIR_P(@var{filename})} (@pxref{Programming in M4sh}).
+
+
 @item @command{mv}
 @c ---------------
 @prindex @command{mv}