X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=blobdiff_plain;f=README;h=e3259c0924414e19770c5fa42007646696ddbdab;hp=67ce6cc17c8fd3755ecddf39a675a073850f11ff;hb=033421585dfa781211b558d7acc310b8540ba60e;hpb=503a7e5169b4a18e2ad2569daeb9e13a99f21070

diff --git a/README b/README
index 67ce6cc..e3259c0 100644
--- 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