Warning reporting: Warning suppression system

[subdirmk.git] / generate

diff --git a/generate b/generate
index 4014471a43019cec4e683d1d3ab60e4b82e6edc8..3caf4e65a0bac0d559c7d891904cefae29584179 100755 (executable)
--- a/generate
+++ b/generate
@@ -152,6 +152,8 @@ Makefile run-main.mk:
 END
 }
 
+our %varref;
+
 our ($dir_prefix, $dir_suffix, $dir_name,
      $var_prefix, $var_prefix_name);
 
@@ -171,11 +173,34 @@ sub set_dir_vars ($) {
 
 our $err_file;
 
+our @warn_ena_dfl = map { $_ => 1 } qw(
+    local+global
+    single-char-var
+    unknown-warning
+);
+our %warn_ena = @warn_ena_dfl;
+
+our $warned;
+our %warn_unk;
+
 sub err ($) {
     my ($m) = @_;
     die "subdirmk: ${err_file}:$.: $m\n";
 }
 
+sub wrncore ($$) {
+    my ($wk,$m) = @_;
+    return 0 unless $warn_ena{$wk} // warn "internal error $wk ?";
+    $warned++;
+    print STDERR "subdirmk: warning ($wk): $m\n";
+    return 1;
+}
+
+sub wrn ($$) {
+    my ($wk,$m) = @_;
+    wrncore($wk, "${err_file}:$.: $m");
+}
+
 sub ddbl_only ($) {
     my ($e) = @_;
     return if $ddbl;
@@ -216,6 +241,7 @@ sub process_input_mk ($$$$) {
 
     local $ddbl;
     my @nest = (['']);
+    my $evalcall_brackets;
 
     my $push_nest = sub {
        my ($nk, $nndbl, $what) = @_;
@@ -229,7 +255,18 @@ sub process_input_mk ($$$$) {
        $ddbl = (shift @nest)[1];
     };
 
+    # Our detection of variable settings does not have to be completely
+    # accurate, since it is only going to be used for advice to the user.
+    my $note_varref = sub {
+       my ($vn,$amp) = @_;
+       $varref{$vn}{$amp}{"$f:$."} = 1;
+    };
+
     while (<$input>) {
+       if (m#^\s*($esc)?(\w+)\s*(?:=|\+=|\?=|:=)# ||
+           m#^\s*(?:$esc\:macro|define)\s+($esc)?(\S+)\s#) {
+           $note_varref->($2,!!$1);
+       }
        if (s#^\s*$esc\:changequote\s+(\S+)\s+$##) {
            $$esclitr = $1;
            $set_esc->();
@@ -238,29 +275,59 @@ sub process_input_mk ($$$$) {
            $pop_nest->('macro');
            od "endef\n";
            next;
+       } elsif (s#^\s*$esc\:warn\s+(\S.*)$##) {
+           foreach my $wk (split /\s+/, $1) {
+               my $yes = $wk !~ s{^!}{};
+               if (defined $warn_ena{$wk}) {
+                   $warn_ena{$wk} = $yes;
+                   next;
+               } elsif ($yes) {
+                   wrn 'unknown-warning',
+                       "unknown warning $wk requested";
+               } else {
+                   $warn_unk{$wk} //= "$f:$.";
+               }
+           }
+           next;
        } elsif (s#^\s*$esc\:(?=(-?)include|macro)##) {
            $buffering_output='';
        } elsif (m#^\s*$esc\:([a-z][-0-9a-z_]*)#) {
            err "unknown directive &:$1 or bad argumnt syntax";
        } elsif (s{^\s*${esc}TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
            my $t = $1 // 'all';
-           od target_varname($var_prefix, $t);
+           my $vn = target_varname($var_prefix, $t);
+           $note_varref->($vn,1);
+           od $vn;
            $targets->{$t} //= [ ];
        }
        for (;;) {
            err 'cannot $-double &-processed RHS of directive'
                if $ddbl && defined $buffering_output;
            unless ($nest[0][0] eq 'eval'
-                   ? s{^(.*?)($esc|[{}])}{}
-                   : s{^(.*?)($esc)}{}) { od $_; last; }
+                   ? s{^(.*?)($esc|\$|[{}])}{}
+                   : s{^(.*?)($esc|\$)}{}) { od $_; last; }
            od $1;
            if ($2 eq '{') {
-               $ddbl++;
+               od $2;
+               $evalcall_brackets++;
                next;
            } elsif ($2 eq '}') {
-               next if --$ddbl;
+               od $2;
+               next if --$evalcall_brackets;
                $pop_nest->('eval');
-               od '}}';
+               od '}';
+               next;
+           } elsif ($2 eq '$') {
+               od $2;
+               if (s{^\$}{}) { od $&; }
+               elsif (m{^[a-zA-Z]\w}) {
+                   wrn 'single-char-var',
+                   'possibly confusing unbracketed single-char $-expansion';
+               }
+               elsif (m{^\(($esc)?([^()\$]+)\)} ||
+                      m{^\{($esc)?([^{}\$]+)\}}) {
+                   $note_varref->($2,!!$1);
+               }
                next;
            }
            if (s{^\\$esc}{}) { od "$$esclitr" }
@@ -268,7 +335,10 @@ sub process_input_mk ($$$$) {
            elsif (s{^\\\s+$}{}) { }
            elsif (s{^$esc}{}) { od "$$esclitr$$esclitr" }
            elsif (m{^(?=$caps_re)}) { od $var_prefix }
-           elsif (s{^\$([A-Za-z]\w+)}{}) { od "\$(${var_prefix}$1)" }
+           elsif (s{^\$([A-Za-z]\w+)}{}) {
+               $note_varref->($1,1);
+               od "\$(${var_prefix}$1)";
+           }
            elsif (s{^([~^]?)(?=$lc_re)}{}) { od $pfxmap{$1} }
            elsif (s{^_}{}) { od $var_prefix }
            elsif (s{^=}{}) { od $var_prefix_name }
@@ -277,12 +347,17 @@ sub process_input_mk ($$$$) {
            elsif (s{^([~^])\.}{}) { od $srcdirmap{$1} }
            elsif (s{^\$\-}{}) { $ddbl=undef; }
            elsif (s{^\$\+}{}) { $ddbl=1; }
-           elsif (s{^\$\(}{}) { ddbl_only($&); oud "\$("; }
+           elsif (s{^\$\(}{}) {
+               ddbl_only($&); oud "\$(";
+               $note_varref->($2,!!$1) if m{^($esc)?([^()\$]+\))};
+           }
            elsif (s{^\$(\d+)}{}) { ddbl_only($&); oud "\$($1)"; }
            elsif (s{^\$\{}{}) {
                err 'macro invocation cannot be re-$-doubled' if $ddbl;
                od '${eval ${call ';
+               $evalcall_brackets = 1;
                $push_nest->('eval',1, '&${...}');
+               $note_varref->($2,!!$1) if m{^\s*($esc)?([^,{}\$]+)};
            } elsif (s{^([~^]?)(?=[ \t])}{}) {
                my $prefix = $pfxmap{$1} // die "internal error ($1?)";
                my $after='';
@@ -359,6 +434,7 @@ sub process_subtree ($$) {
        my @childpath = (@$path, $child->[0]);
        my $child_subdir = join '/', @childpath;
        mkdir $child_subdir or $!==EEXIST or die "mkdir $child_subdir: $!\n";
+       local %warn_ena = @warn_ena_dfl;
        push @{ $targets{$_} }, $child_subdir foreach
            process_subtree($child, \@childpath);
     }
@@ -431,6 +507,33 @@ sub process_tree() {
     oraw "include \$(SUBDIRMK_MAKEFILES)\n";
 }
 
+sub flmap ($) { local ($_) = @_; s{:(\d+)$}{ sprintf ":%10d", $1 }e; $_; }
+
+sub print_varref_warnings () {
+    foreach my $vn (sort keys %varref) {
+       my $vv = $varref{$vn};
+       next unless $vv->{''} && $vv->{1};
+       wrncore 'local+global', "saw both $vn and &$vn" or return;
+       foreach my $amp ('', 1) {
+           printf STDERR " saw %s%s at %s\n",
+               ($amp ? '&' : ''), $vn, $_
+               foreach
+               sort { flmap($a) cmp flmap($b) }
+               keys %{ $vv->{$amp} };
+       }
+    }
+}
+
+sub print_warning_warnings () {
+    return unless $warned;
+    foreach my $wk (sort keys %warn_unk) {
+       wrncore 'unknown-warning',
+           "$warn_unk{$wk}: attempt to suppress unknown warning(s) \`$wk'";
+    }
+}
+
 build_tree();
 process_tree();
+print_varref_warnings();
+print_warning_warnings();
 install_output_files();