From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 29 Dec 2019 15:18:39 +0000 (+0000)
Subject: Syntax: Rescope effect of &:local+global
X-Git-Tag: subdirmk/0.3~9
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=commitdiff_plain;h=4f0ba0e06ccac804cf0dcc9b9d8c3628e35d2336;hp=f2f72a3200b1d81fa84232c03834addbe1bc3547

Syntax: Rescope effect of &:local+global

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

diff --git a/README b/README
index 2f1a1ce..415913b 100644
--- a/README
+++ b/README
@@ -175,9 +175,9 @@ So pathname syntax is a subset of:
 	input files (including Final.sd.mk).
 
 &:local+global [&]VARIABLE ...
-	Suppresses the warning about seeing both VARIABLE and
-	&VARIABLE.  Any & specified in the RHS is redundant: this
-	always affects both versions identically.
+	Suppresses any warnings relating to forthcoming mentions
+	to VARIABLE or &VARIABLE, as applicable.  Scope ends at
+	the end of the current directory's Suffix.sd.mk.
 
 &:changequote NEWQUOTE
 	changes the escape sequence from & to literally NEWQUOTE
diff --git a/generate b/generate
index f91cba8..2278928 100755
--- a/generate
+++ b/generate
@@ -153,6 +153,7 @@ END
 }
 
 our %varref;
+our %varref_exp;
 
 our ($dir_prefix, $dir_suffix, $dir_name,
      $var_prefix, $var_prefix_name);
@@ -262,6 +263,7 @@ sub process_input_mk ($$$$) {
     # accurate, since it is only going to be used for advice to the user.
     my $note_varref = sub {
 	my ($vn,$amp) = @_;
+	return if $varref_exp{$vn}{$amp};
 	$varref{$vn}{$amp}{"$f:$."} = 1;
     };
 
@@ -294,8 +296,8 @@ sub process_input_mk ($$$$) {
 	    next;
 	} elsif (s#^\s*$esc\:local\+global\s+(\S.*)$##) {
 	    foreach my $vn (split /\s+/, $1) {
-		$vn =~ s{^$esc}{};
-		$varref{$vn}{NoWarn} = 1;
+		my $amp = $vn =~ s{^$esc}{};
+		$varref_exp{$vn}{!!$amp} = 1;
 	    }
 	    next;
 	} elsif (s#^\s*$esc\:(?=(-?)include|macro)##) {
@@ -435,6 +437,8 @@ sub process_subtree ($$) {
     #use Data::Dumper;
     #print STDERR Dumper(\@_);
 
+    local %varref_exp;
+
     my $dir_prefix = dir_prefix($path);
     # ^ this is the only var which we need before we come back from
     #   the recursion.
@@ -526,7 +530,6 @@ sub print_varref_warnings () {
     foreach my $vn (sort keys %varref) {
 	my $vv = $varref{$vn};
 	next unless $vv->{''} && $vv->{1};
-	next if $vv->{NoWarn};
 	wrncore 'local+global', "saw both $vn and &$vn" or return;
 	foreach my $amp ('', 1) {
 	    printf STDERR " saw %s%s at %s\n",
diff --git a/tests/filter/stderr.expected b/tests/filter/stderr.expected
index 76e32dd..0b4f656 100644
--- a/tests/filter/stderr.expected
+++ b/tests/filter/stderr.expected
@@ -4,7 +4,10 @@ subdirmk: warning (broken-var-ref): ./Dir.sd.mk:19: broken $&... expansion; you
 subdirmk: warning (local+global): saw both WARN and &WARN
  saw WARN at ./Dir.sd.mk:6
  saw WARN at ./Dir.sd.mk:9
+ saw WARN at ./sub/dir/Dir.sd.mk:16
+ saw WARN at ./sub/dir/Dir.sd.mk:19
  saw &WARN at ./Dir.sd.mk:7
  saw &WARN at ./Dir.sd.mk:10
  saw &WARN at ./Dir.sd.mk:11
+ saw &WARN at ./sub/dir/Dir.sd.mk:15
 subdirmk: warning (unknown-warning): ./sub/dir/Dir.sd.mk:3: attempt to suppress unknown warning(s) `some-unknown-warning'
diff --git a/tests/filter/sub/dir/Dir.mk.expected b/tests/filter/sub/dir/Dir.mk.expected
index 812e51b..f545495 100644
--- a/tests/filter/sub/dir/Dir.mk.expected
+++ b/tests/filter/sub/dir/Dir.mk.expected
@@ -11,6 +11,11 @@ sub_dir_TARGETS_sometarget2
 
 line joining
 
+sub_dir_WARN += 4
+WARN += 4
+sub_dir_WARN += 5 # this warning suppressed, precisely
+WARN += 5
+
 # doctests:
 # Suffix in sub/dir
 
diff --git a/tests/filter/sub/dir/Dir.sd.mk b/tests/filter/sub/dir/Dir.sd.mk
index 4b5a50c..a939bbf 100644
--- a/tests/filter/sub/dir/Dir.sd.mk
+++ b/tests/filter/sub/dir/Dir.sd.mk
@@ -12,5 +12,11 @@
 line &\
 joining
 
+&WARN += 4
+WARN += 4
+&:local+global &WARN
+&WARN += 5 # this warning suppressed, precisely
+WARN += 5
+
 # doctests:
 &:include &doctests.sd.mk