Interface: Rename Perdir to Suffix; provide Prefix

[subdirmk.git] / README

diff --git a/README b/README
index 67ce6cc17c8fd3755ecddf39a675a073850f11ff..e3259c0924414e19770c5fa42007646696ddbdab 100644 (file)
--- a/README
+++ b/README
@@ -90,20 +90,21 @@ Unlike `all', these other targets only exist in areas of the project
 where at least something mentions them.  So for example, if
 &TARGETS_zonk is mentioned in src but not lib, `make zonk' in
 lib will fail.  If you want to make a target exist everywhere,
-mention its name in Perdir.sd.mk (see below).
+mention its name in Prefix.sd.mk or Suffix.sd.mk (see below).
 
-Perdir.sd.mk, inclusion
------------------------
+Prefix.sd.mk, Suffix.sd.mk, inclusion
+-------------------------------------
 
-The file Perdir.sd.mk in the toplevel of the source is automatically
-processed after each individual directory's Subdir.sd.mk, and the
-&-substituted contents therefore appear once for each subdirectory.
+The files Prefix.sd.mk and Suffix.sd.mk in the toplevel of the source
+are automatically processed before and after each individual
+directory's Subdir.sd.mk, and the &-substituted contents therefore
+appear once for each subdirectory.
 
 This lets you do per-directory boilerplate.  Some useful boilerplate
 is already provided in subdirmk, for you to reference like this:
   &:include subdirmk/cdeps.sd.mk
   &:include subdirmk/clean.sd.mk
-For example you could put that in Perdir.sd.mk.
+For example you could put that in Suffix.sd.mk.
 
 The top-level Subdir.sd.mk is the first makefile included after the
 autogenerated `main.mk' which merely has some basic settings and
@@ -147,7 +148,7 @@ There are two kinds of template files.
  How to include           `&:include foo.sd.mk'   `include foo.mk'
                          in all relevant .sd.mk  in only one
                           (but not needed for     Subdir.sd.mk
-                           Subdir and Perdir)
+                           Prefix, Suffix)
 
 If you `include subdirmk/regen.mk', dependency management and
 automatic regeneration for all of this template substitution, and for
@@ -247,7 +248,13 @@ So pathname syntax is a subset of:
     '&' [ '^' | '~' ] [ lc | '/' | '.' | '=' ]
 
 &&             =>      &&              for convenience in shell runes
-\&             =>      &               general escaping mechanism
+
+&\&            =>      &               general escaping mechanism
+&\$            =>      $
+&\NEWLINE                              eats the newline and vanishes
+
+&$VARIABLE     =>      $(sub_dir_VARIABLE)     or $(TOP_VARIABLE)
+       VARIABLE is ASCII starting with a letter and matching \w+
 
 & thing thing... &
 &^ thing thing... &
@@ -261,35 +268,37 @@ So pathname syntax is a subset of:
 
 &:<directive> <args>....
        recognised at start of line only (possibly after lwsp)
-       args are processed for &
 
-&:include filename             filename should usually be foo.sd.mk
+&:include filename             filename should usually be [&]foo.sd.mk
 &:-include filename            tolerate nonexistent file
        filenames are relative to $(top_srcdir)
+       RHS is &-expanded
 
 &!<lwsp>       disables & until EOL (and then disappears)
 
 &#     delete everything to end of line
        (useful if the RHS contains unrecognised & constructions)
 
-&:changequote STUFF
-       changes the escape sequence from & to literally STUFF
-       STUFF may be any series of of non-whitespace characters,
+&:changequote NEWQUOTE
+       changes the escape sequence from & to literally NEWQUOTE
+       NEWQUOTE may be any series of of non-whitespace characters,
        and is terminated by EOL or lwsp.  The whole line is
        discarded.
 
-       After this, write STUFF instead of &, everywhere.
+       After this, write NEWQUOTE instead of &, everywhere.
        The effect is global and lasts until the next setting.
        It takes effect on &:include'd files too, so maybe set
        it back before using &:include.
 
        Notably
-               STUFFSTUFF              => STUFFSTUFF
-               \STUFF                  => STUFF
-               STUFF:changequote &     => set escape back to &
+               NEWQUOTENEWQUOTE        => NEWQUOTENEWQUOTE
+               NEWQUOTE\NEWQUOTE       => NEWQUOTE
+               NEWQUOTE\$              => $
+               NEWQUOTE:changequote &  set escape back to &
 
 &TARGETS_things
-       Handled specially.  If mentioned, declares that this
+       Handled specially.  If mentioned at the start of a line
+       (possibly following whitespace), declares that this
        subdir ought to have a target `things'.  The rule will be
                &/things:: $(&TARGETS_things)
 
@@ -303,9 +312,9 @@ So pathname syntax is a subset of:
        which recursively implies this directory's `things'.
 
        Must be spelled exactly &TARGETS_things.  &_TARGETS_things,
-       for example, is not magic.  But mentioning &TARGETS_things in
-       a #-comment *does* work because the & filter does not care
-       about comments.
+       for example, is not magic.  To make the target exist
+       without providing any prerequisites for it, write a line
+       containing just `&TARGETS_things +='.
 
        `all' is extra special: every directory has an `all'
        target, which corresponds to &TARGETS.
@@ -346,7 +355,7 @@ probably contain:
   include subdirmk/usual.mk
   include subdirmk/regen.mk
 
-Write a Perdir.sd.mk in the toplevel, if you want.  It should probably
+Write a Suffix.sd.mk in the toplevel, if you want.  It should probably
 have:
 
   &:include subdirmk/cdeps.sd.mk