X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=generate;h=2a65d991ceb466d193002138abfab1f573d0f4b2;hb=4110b41e20eb2c12fe68cdcb994ee47e7e25ec18;hp=52a0ec8262522076de57b00cbe6013dd04a8d59d;hpb=8c3e6dc4a16406496aa6991f8dc2fb77a96359ea;p=subdirmk.git

diff --git a/generate b/generate
index 52a0ec8..2a65d99 100755
--- a/generate
+++ b/generate
@@ -19,6 +19,22 @@ print "$0 @ARGV\n" or die $!;
 
 our $srcdir='.';
 
+# error handling methods:
+#
+# Error in input file, while $err_file and $. set, eg in most of
+# process_input_mk:
+#         err "message";
+#
+# Other input or usage errors:
+#         die "$0: $file:$lno: problem\n";
+#         die "$0: some problem not locatable in that way\n";
+#
+# System call error (not ENOENT) accessing input/output files:
+#         die "description of problem eg maybe erbing noun: $!\n";
+#
+# Bug detedcted in `generate':
+#         die "internal error (some information)?"; # or similar
+
 while (@ARGV && $ARGV[0] =~ m/^-/) {
     $_ = shift @ARGV;
     last if $_ eq '--';
@@ -70,7 +86,7 @@ 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";
 }
 
@@ -99,7 +115,8 @@ 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: $!\n";
     oraw "# autogenerated - do not edit\n";
@@ -149,6 +166,19 @@ sub set_dir_vars ($) {
     $var_prefix = "${var_prefix_name}_";
 }
 
+our $err_file;
+
+sub err ($) {
+    my ($m) = @_;
+    die "$0: ${err_file}:$.: $m\n";
+}
+
+sub ddbl_only ($) {
+    my ($e) = @_;
+    return if $ddbl;
+    err "escape &$e is valid only during \$-doubling";
+}
+
 sub process_input_mk ($$$$);
 sub process_input_mk ($$$$) {
     my ($targets, $f, $esclitr, $enoent_ok) = @_;
@@ -165,11 +195,13 @@ sub process_input_mk ($$$$) {
 
     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}++;
 
+    local $err_file=$f;
+
     my %srcdirmap = (
 		  '^' => "\$(top_srcdir)${dir_suffix}",
 		  '~' => "\$(top_srcdir)",
@@ -180,7 +212,7 @@ sub process_input_mk ($$$$) {
     $pfxmap{$_} = $srcdirmap{$_}.'/' foreach keys %srcdirmap;
 
     local $ddbl;
-    my @nest;
+    my @nest = (['']);
 
     my $push_nest = sub {
 	my ($nk, $nndbl) = @_;
@@ -190,6 +222,7 @@ sub process_input_mk ($$$$) {
     my $pop_nest = sub {
 	my ($nk) = @_;
 	die unless $nest[0][0] eq $nk;
+	# ^ xxx need better message
 	$ddbl = (shift @nest)[1];
     };
 
@@ -205,15 +238,16 @@ sub process_input_mk ($$$$) {
 	} elsif (s#^\s*$esc\:(?=(-?)include|macro)##) {
 	    $buffering_output='';
 	} elsif (m#^\s*$esc\:([a-z][-0-9a-z_]*)#) {
-	    die "unknown directive $1";
+	    err "unknown directive &:$1";
 	} elsif (s{^\s*${esc}TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
 	    my $t = $1 // 'all';
 	    od target_varname($var_prefix, $t);
 	    $targets->{$t} //= [ ];
 	}
 	for (;;) {
-	    die if $ddbl && defined $buffering_output;
-	    unless (@nest && $nest[0][0] eq 'Eval'
+	    err 'cannot $-double &-processed RHS of directive'
+		if $ddbl && defined $buffering_output;
+	    unless ($nest[0][0] eq 'Eval'
 		    ? s{^(.*?)($esc|[{}])}{}
 		    : s{^(.*?)($esc)}{}) { od $_; last; }
 	    od $1;
@@ -240,14 +274,14 @@ sub process_input_mk ($$$$) {
 	    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);
 	    } 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;
@@ -259,7 +293,7 @@ sub process_input_mk ($$$$) {
 		od $_;
 		$_ = '';
 	    } else {
-		die "bad escape $$esclitr$_ ";
+		err "bad &-escape \`$$esclitr$_'";
 	    }
 	}
 	if (defined $buffering_output) {
@@ -273,10 +307,11 @@ sub process_input_mk ($$$$) {
 		od "define $1\n";
 		$push_nest->('Macro', 1);
 	    } else {
-		die "internal error buffering directive $_ ";
+		die "internal error ($_?)";
 	    }
 	}
     }
+    die "unclosed $nest[0][0]" if $nest[0][0];
     $input->error and die "read $f: $!\n";
     close $input or die "close $f: $!\n";
 }
@@ -318,7 +353,7 @@ sub process_subtree ($$) {
     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);
     }
@@ -331,10 +366,11 @@ sub process_subtree ($$) {
     } else {
 	my $sdmk = "${dir_prefix}Subdir.sd.mk";
 	if (stat $sdmk) {
-	    die "$sdmk unexpectedly exists (${dir_prefix} not mentioned)";
+	    die
+ "$0: $sdmk unexpectedly exists (${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";
 	}
     }
 
@@ -368,7 +404,8 @@ 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 "$0: Final.sd.mk may not introduce new top-level targets".
+	" (@ntargets)\n" if @ntargets;
 }
 
 sub process_tree() {