From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sat, 28 Dec 2019 00:27:13 +0000 (+0000)
Subject: Error handling: Replace or update many calls to `die'
X-Git-Tag: subdirmk/0.3~56
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ian/git?p=subdirmk.git;a=commitdiff_plain;h=4110b41e20eb2c12fe68cdcb994ee47e7e25ec18;ds=sidebyside

Error handling: Replace or update many calls to `die'

To conform to new approach.

The `ending wrong kind of nest' error will be dealt with in a moment.

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

diff --git a/generate b/generate
index 84572ed..2a65d99 100755
--- a/generate
+++ b/generate
@@ -86,7 +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";
 }
 
@@ -115,7 +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";
@@ -194,7 +195,7 @@ 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}++;
@@ -221,6 +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];
     };
 
@@ -236,14 +238,15 @@ sub process_input_mk ($$$$) {
 	} elsif (s#^\s*$esc\:(?=(-?)include|macro)##) {
 	    $buffering_output='';
 	} elsif (m#^\s*$esc\:([a-z][-0-9a-z_]*)#) {
-	    die "unknown directive $1";
+	    err "unknown directive &:$1";
 	} elsif (s{^\s*${esc}TARGETS(?:_([0-9a-zA-Z_]+))?(?=\W)}{}) {
 	    my $t = $1 // 'all';
 	    od target_varname($var_prefix, $t);
 	    $targets->{$t} //= [ ];
 	}
 	for (;;) {
-	    die if $ddbl && defined $buffering_output;
+	    err 'cannot $-double &-processed RHS of directive'
+		if $ddbl && defined $buffering_output;
 	    unless ($nest[0][0] eq 'Eval'
 		    ? s{^(.*?)($esc|[{}])}{}
 		    : s{^(.*?)($esc)}{}) { od $_; last; }
@@ -271,14 +274,14 @@ sub process_input_mk ($$$$) {
 	    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;
@@ -290,7 +293,7 @@ sub process_input_mk ($$$$) {
 		od $_;
 		$_ = '';
 	    } else {
-		die "bad escape $$esclitr$_ ";
+		err "bad &-escape \`$$esclitr$_'";
 	    }
 	}
 	if (defined $buffering_output) {
@@ -304,7 +307,7 @@ sub process_input_mk ($$$$) {
 		od "define $1\n";
 		$push_nest->('Macro', 1);
 	    } else {
-		die "internal error buffering directive $_ ";
+		die "internal error ($_?)";
 	    }
 	}
     }
@@ -350,7 +353,7 @@ sub process_subtree ($$) {
     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);
     }
@@ -363,10 +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";
 	}
     }
 
@@ -400,7 +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() {