@maindex PROG_INSTALL
Set @code{make} variable @code{INSTALL} to @samp{install -c} if
@code{install} is found and is compatible with the BSD and GNU versions.
-Otherwise, set @code{INSTALL} to @samp{@var{srcdir}/install.sh -c} if that
+Otherwise, set @code{INSTALL} to @samp{@@top_srcdir@@/install.sh -c} if that
script exists, or to @samp{cp} as a last resort. Screens out the
false matches @file{/etc/install}, @file{/usr/sbin/install}, and other
instances of @code{install} known not to work. Also sets the variable
@xref{Installation Prefixes}, for an alternate way to set this variable.
@end defvar
+@defvar top_srcdir
+The top-level source code directory for the package. In the top-level
+directory, this is the same as @code{srcdir}.
+@end defvar
+
@defvar DEFS
@samp{-D} options to pass to the C compiler. If @code{AC_CONFIG_HEADER}
is called, @code{configure} replaces @samp{@@DEFS@@} with
@maindex PROG_INSTALL
Set @code{make} variable @code{INSTALL} to @samp{install -c} if
@code{install} is found and is compatible with the BSD and GNU versions.
-Otherwise, set @code{INSTALL} to @samp{@var{srcdir}/install.sh -c} if that
+Otherwise, set @code{INSTALL} to @samp{@@top_srcdir@@/install.sh -c} if that
script exists, or to @samp{cp} as a last resort. Screens out the
false matches @file{/etc/install}, @file{/usr/sbin/install}, and other
instances of @code{install} known not to work. Also sets the variable
@xref{Installation Prefixes}, for an alternate way to set this variable.
@end defvar
+@defvar top_srcdir
+The top-level source code directory for the package. In the top-level
+directory, this is the same as @code{srcdir}.
+@end defvar
+
@defvar DEFS
@samp{-D} options to pass to the C compiler. If @code{AC_CONFIG_HEADER}
is called, @code{configure} replaces @samp{@@DEFS@@} with