From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Mon, 9 Dec 2019 15:05:22 +0000 (+0000)
Subject: Syntax: Refine &TARGETS_things, mostly to avoid # wrinkle
X-Git-Tag: subdirmk/0.3~97
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=commitdiff_plain;h=74b432cc45d829f428a713800ec007dbdf666c37;ds=sidebyside

Syntax: Refine &TARGETS_things, mostly to avoid # wrinkle

We will add a test case in a moment, since it is quite a noisy diff.

We have to upate clean.sd.mk, which uses this feature.

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>
---

diff --git a/README b/README
index 63e4188..fd10056 100644
--- a/README
+++ b/README
@@ -295,7 +295,8 @@ So pathname syntax is a subset of:
 		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)
 
@@ -309,9 +310,9 @@ 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.
diff --git a/clean.sd.mk b/clean.sd.mk
index 045561c..80c40bc 100644
--- a/clean.sd.mk
+++ b/clean.sd.mk
@@ -19,7 +19,7 @@
 &CLEAN += $(&OBJECTS)
 &CLEAN += $(&TARGETS)
 
-# &TARGETS_clean
+&TARGETS_clean +=
 
 &/clean::
 	$(RM) $(&CLEAN)
diff --git a/generate b/generate
index e1efc06..e853912 100755
--- a/generate
+++ b/generate
@@ -155,6 +155,10 @@ sub process_input_mk ($$$$$$$$$) {
 	    $buffering_output='';
 	} elsif (m#^\s*$esc\:([a-z][-0-9a-z_]*)#) {
 	    die "unknown directive $1";
+	} elsif (s{^\s*${esc}TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
+	    my $t = $1 // 'all';
+	    o target_varname($var_prefix, $t);
+	    $targets->{$t} //= [ ];
 	}
 	for (;;) {
 	    unless (s{^(.*?)$esc}{}) { o $_; last; }
@@ -162,11 +166,6 @@ sub process_input_mk ($$$$$$$$$) {
 	    if (s{^\\$esc}{}) { o "$$esclitr" }
 	    elsif (s{^\\\$}{}) { o '$' }
 	    elsif (s{^$esc}{}) { o "$$esclitr$$esclitr" }
-	    elsif (s{^TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
-		my $t = $1 // 'all';
-		o target_varname($var_prefix, $t);
-		$targets->{$t} //= [ ];
-	    }
 	    elsif (m{^(?=$caps_re)}) { o $var_prefix }
 	    elsif (s{^\$([A-Za-z]\w+)}{}) { o "\$(${var_prefix}$1)" }
 	    elsif (s{^([~^]?)(?=$lc_re)}{}) { o $pfxmap{$1} }