Error handling: Trim the `bad escape' message.e

[subdirmk.git] / generate

diff --git a/generate b/generate
index 84572edc2ef842e0ceffacd884aa306851518831..62e915fb35df1065f466a1c25b5f4312b52bc726 100755 (executable)
--- a/generate
+++ b/generate
@@ -26,8 +26,11 @@ our $srcdir='.';
 #         err "message";
 #
 # Other input or usage errors:
-#         die "$0: $file:$lno: problem\n";
-#         die "$0: some problem not locatable in that way\n";
+#         die "subdirmk: $file:$lno: problem\n";
+#         die "subdirmk: some problem not locatable in that way\n";
+#
+# Usage error:
+#         die "subdirmk $0: explanation of problem\n";
 #
 # System call error (not ENOENT) accessing input/output files:
 #         die "description of problem eg maybe erbing noun: $!\n";
@@ -41,7 +44,7 @@ while (@ARGV && $ARGV[0] =~ m/^-/) {
     if (s/^--srcdir=//) {
        $srcdir=$';
     } else {
-       die "$0: unknown option \`$_'\n";
+       die "subdirmk $0: unknown option \`$_'\n";
     }
 }
 our @subdirs = @ARGV;
@@ -86,7 +89,7 @@ sub close_any_output_file() {
 }
 
 sub oraw {
-    die unless defined $writing_output;
+    die 'internal error' unless defined $writing_output;
     print O @_ or die "error writing $writing_output.tmp: $!\n";
 }
 
@@ -115,7 +118,8 @@ sub od { # maybe $-doubled
 sub start_output_file ($) {
     close_any_output_file();
     ($writing_output) = @_;
-    die "$writing_output ?" if $output_files{$writing_output}++;
+    die "internal error ($writing_output?)"
+       if $output_files{$writing_output}++;
     my $tmp = "$writing_output.tmp";
     open O, ">", $tmp or die "create $tmp: $!\n";
     oraw "# autogenerated - do not edit\n";
@@ -169,7 +173,7 @@ our $err_file;
 
 sub err ($) {
     my ($m) = @_;
-    die "$0: ${err_file}:$.: $m\n";
+    die "subdirmk: ${err_file}:$.: $m\n";
 }
 
 sub ddbl_only ($) {
@@ -194,7 +198,7 @@ sub process_input_mk ($$$$) {
 
     my $input = new IO::File $f, '<';
     if (!$input) {
-       die "open $f: $!\n" unless $!==ENOENT && $enoent_ok;
+       err "open $f: $!" unless $!==ENOENT && $enoent_ok;
        return;
     }
     $input_files{$f}++;
@@ -214,13 +218,14 @@ sub process_input_mk ($$$$) {
     my @nest = (['']);
 
     my $push_nest = sub {
-       my ($nk, $nndbl) = @_;
-       unshift @nest, [ $nk, $ddbl ];
+       my ($nk, $nndbl, $what) = @_;
+       unshift @nest, [ $nk, $ddbl, $what, $. ];
        $ddbl = $nndbl;
     };
     my $pop_nest = sub {
        my ($nk) = @_;
-       die unless $nest[0][0] eq $nk;
+       err "unexpectedly closed $nk in middle of $nest[0][0] ($nest[0][2])"
+           unless $nest[0][0] eq $nk;
        $ddbl = (shift @nest)[1];
     };
 
@@ -236,14 +241,15 @@ sub process_input_mk ($$$$) {
        } elsif (s#^\s*$esc\:(?=(-?)include|macro)##) {
            $buffering_output='';
        } elsif (m#^\s*$esc\:([a-z][-0-9a-z_]*)#) {
-           die "unknown directive $1";
+           err "unknown directive &:$1";
        } elsif (s{^\s*${esc}TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
            my $t = $1 // 'all';
            od target_varname($var_prefix, $t);
            $targets->{$t} //= [ ];
        }
        for (;;) {
-           die if $ddbl && defined $buffering_output;
+           err 'cannot $-double &-processed RHS of directive'
+               if $ddbl && defined $buffering_output;
            unless ($nest[0][0] eq 'Eval'
                    ? s{^(.*?)($esc|[{}])}{}
                    : s{^(.*?)($esc)}{}) { od $_; last; }
@@ -271,14 +277,14 @@ sub process_input_mk ($$$$) {
            elsif (s{^([~^])\.}{}) { od $srcdirmap{$1} }
            elsif (s{^\$\-}{}) { $ddbl=undef; }
            elsif (s{^\$\+}{}) { $ddbl=1; }
-           elsif (s{^\$\(}{}) { die unless $ddbl; oud "\$("; }
-           elsif (s{^\$(\d+)}{}) { die unless $ddbl; oud "\$($1)"; }
+           elsif (s{^\$\(}{}) { ddbl_only($&); oud "\$("; }
+           elsif (s{^\$(\d+)}{}) { ddbl_only($&); oud "\$($1)"; }
            elsif (s{^\$\{}{}) {
-               die if $ddbl;
+               err 'macro invocation cannot be re-$-doubled' if $ddbl;
                od '${eval ${call ';
-               $push_nest->('Eval',1);
+               $push_nest->('Eval',1, '&${...}');
            } elsif (s{^([~^]?)(?=[ \t])}{}) {
-               my $prefix = $pfxmap{$1} // die;
+               my $prefix = $pfxmap{$1} // die "internal error ($1?)";
                my $after='';
                if (m{([ \t])$esc}) { ($_,$after) = ($`, $1.$'); }
                s{(?<=[ \t])(?=\S)(?!\\\s*$)}{$prefix}g;
@@ -290,7 +296,8 @@ sub process_input_mk ($$$$) {
                od $_;
                $_ = '';
            } else {
-               die "bad escape $$esclitr$_ ";
+               m{^.{0,5}};
+               err "bad &-escape \`$$esclitr$&'";
            }
        }
        if (defined $buffering_output) {
@@ -304,11 +311,12 @@ sub process_input_mk ($$$$) {
                od "define $1\n";
                $push_nest->('Macro', 1);
            } else {
-               die "internal error buffering directive $_ ";
+               die "internal error ($_?)";
            }
        }
     }
-    die "unclosed $nest[0][0]" if $nest[0][0];
+    die "subdirmk: $f:$nest[0][3]: unclosed $nest[0][0] ($nest[0][2])\n"
+       if $nest[0][0];
     $input->error and die "read $f: $!\n";
     close $input or die "close $f: $!\n";
 }
@@ -350,7 +358,7 @@ sub process_subtree ($$) {
     foreach my $child (@{ $node->[1] }) {
        my @childpath = (@$path, $child->[0]);
        my $child_subdir = join '/', @childpath;
-       mkdir $child_subdir or $!==EEXIST or die "mkdir $child_subdir: $!";
+       mkdir $child_subdir or $!==EEXIST or die "mkdir $child_subdir: $!\n";
        push @{ $targets{$_} }, $child_subdir foreach
            process_subtree($child, \@childpath);
     }
@@ -363,10 +371,11 @@ sub process_subtree ($$) {
     } else {
        my $sdmk = "${dir_prefix}Subdir.sd.mk";
        if (stat $sdmk) {
-           die "$sdmk unexpectedly exists (${dir_prefix} not mentioned)";
+           die
+ "subdirmk: $sdmk unexpectedly exists (${dir_prefix} not mentioned on subdirmk/generate command line, maybe directory is missing from SUBDIRMK_SUBDIRS)";
        } elsif ($!==ENOENT) {
        } else {
-           die "stat $sdmk: $!";
+           die "stat $sdmk: $!\n";
        }
     }
 
@@ -400,7 +409,8 @@ sub process_final ($) {
     process_input_mk(\%ntargets, "${srcdir}/Final.sd.mk", \$esclit, 1);
     delete $ntargets{$_} foreach @$otargets;
     my @ntargets = sort keys %ntargets;
-    die "late new targets @ntargets" if @ntargets;
+    die "subdirmk: Final.sd.mk may not introduce new top-level targets".
+       " (@ntargets)\n" if @ntargets;
 }
 
 sub process_tree() {