automatic regeneration for all of this template substitution, and for
config.status etc. is done for you.
+Summary of recommended directory reference syntaxes
+---------------------------------------------------
+
+Path construction &-expansions, meanings summary:
+
+ In build tree In source tree
+ This directory just & &,
+ Top level &. implies absolute &;
+
+Adding `@' means "absolute path". This is not needed with &. because
+there is never any need to use &. since it would expand to nothing.
+`/' terminates the escape (needed if the next thing is not a lowercase
+character, or space). `=' means "just the value, no /". Space starts
+multi-word processing.
+
+ Recommended In build tree In source tree
+ when Relative Absolute Relative Absolute
+
+ This lc &file &@file &,file &@,file
+ directory any &/file &@/file &,/file &@,/file
+ several & f g h &@ f g h &, f g h &@, f g h
+
+ Top lc &.file &;file &@;file
+ level any file &./file &;/file &@;/file
+ several f g h &. f g h &; f g h &@; f g h
+ .mk.in file $(abs)/file $(src)/file $(abs_src)/file
+
Substitution syntax
-------------------
&^ => $(top_srcdir)/sub/dir or $(top_srcdir)
&~ => $(abs_top_srcdir)/sub/dir or $(abs_top_srcdir)
+In general:
+ ^ filenames in source tree rather than build tree
+ ~ filenames are absolute rather than relative
+ @ filenames do not contain subdir (useful with the above)
+
&& => && for convenience in shell runes
\& => & general escaping mechanism