-#!/usr/local/bin/perl
-eval 'exec perl -S $0 ${1+"$@"}'
- if 0;
-
-use Config;
-if ($Config{'osname'} eq 'VMS') {
- $diagnostics::PODFILE = VMS::Filespec::unixify($Config{'privlib'}) .
- '/pod/perldiag.pod';
-}
-else { $diagnostics::PODFILE= $Config{privlib} . "/pod/perldiag.pod"; }
-
package diagnostics;
-require 5.001;
-use English;
-use Carp;
=head1 NAME
-diagnostics - Perl compiler pragma to force verbose warning diagnostics
-
-splain - standalone program to do the same thing
+diagnostics, splain - produce verbose warning diagnostics
=head1 SYNOPSIS
-As a pragma:
+Using the C<diagnostics> pragma:
use diagnostics;
use diagnostics -verbose;
enable diagnostics;
disable diagnostics;
-Aa a program:
+Using the C<splain> standalone filter program:
perl program 2>diag.out
splain [-v] [-p] diag.out
+Using diagnostics to get stack traces from a misbehaving script:
+
+ perl -Mdiagnostics=-traceonly my_script.pl
=head1 DESCRIPTION
=head2 The C<diagnostics> Pragma
This module extends the terse diagnostics normally emitted by both the
-perl compiler and the perl interpeter, augmenting them wtih the more
+perl compiler and the perl interpreter (from running perl with a -w
+switch or C<use warnings>), augmenting them with the more
explicative and endearing descriptions found in L<perldiag>. Like the
-other pragmata, it affects to compilation phase of your program rather
+other pragmata, it affects the compilation phase of your program rather
than merely the execution phase.
To use in your program as a pragma, merely invoke
Due to the interaction between runtime and compiletime issues,
and because it's probably not a very good idea anyway,
you may not use C<no diagnostics> to turn them off at compiletime.
-However, you may control there behaviour at runtime using the
+However, you may control their behaviour at runtime using the
disable() and enable() methods to turn them off and on respectively.
The B<-verbose> flag first prints out the L<perldiag> introduction before
-any other diagnostics. The $diagnostics::PRETTY can generate nicer escape
-sequences for pgers.
+any other diagnostics. The $diagnostics::PRETTY variable can generate nicer
+escape sequences for pagers.
+
+Warnings dispatched from perl itself (or more accurately, those that match
+descriptions found in L<perldiag>) are only displayed once (no duplicate
+descriptions). User code generated warnings a la warn() are unaffected,
+allowing duplicate user messages to be displayed.
+
+This module also adds a stack trace to the error message when perl dies.
+This is useful for pinpointing what caused the death. The B<-traceonly> (or
+just B<-t>) flag turns off the explanations of warning messages leaving just
+the stack traces. So if your script is dieing, run it again with
+
+ perl -Mdiagnostics=-traceonly my_bad_script
+
+to see the call stack at the time of death. By supplying the B<-warntrace>
+(or just B<-w>) flag, any warnings emitted will also come with a stack
+trace.
=head2 The I<splain> Program
./splain < test.out
Note that this is not in general possible in shells of more dubious heritage,
-as the theorectical
+as the theoretical
(perl -w test.pl >/dev/tty) >& test.out
./splain < test.out
splain package is built. See the F<Makefile> for details.
If an extant $SIG{__WARN__} handler is discovered, it will continue
-to be honored, but only after the diagnostic::splainthis() function
+to be honored, but only after the diagnostics::splainthis() function
(the module's $SIG{__WARN__} interceptor) has had its way with your
warnings.
insurmountable.
The C<-pretty> directive is called too late to affect matters.
-You have to to this instead, and I<before> you load the module.
+You have to do this instead, and I<before> you load the module.
BEGIN { $diagnostics::PRETTY = 1 }
I could start up faster by delaying compilation until it should be
-needed, but this gets a "panic: top_level"
-when using the pragma form in 5.001e.
+needed, but this gets a "panic: top_level" when using the pragma form
+in Perl 5.001e.
While it's true that this documentation is somewhat subserious, if you use
a program named I<splain>, you should expect a bit of whimsy.
=head1 AUTHOR
-Tom Christiansen F<E<lt>tchrist@mox.perl.comE<gt>>, 25 June 1995.
+Tom Christiansen <F<tchrist@mox.perl.com>>, 25 June 1995.
=cut
+use strict;
+use 5.009001;
+use Carp;
+$Carp::Internal{__PACKAGE__.""}++;
+
+our $VERSION = 1.17;
+our $DEBUG;
+our $VERBOSE;
+our $PRETTY;
+our $TRACEONLY = 0;
+our $WARNTRACE = 0;
+
+use Config;
+my($privlib, $archlib) = @Config{qw(privlibexp archlibexp)};
+if ($^O eq 'VMS') {
+ require VMS::Filespec;
+ $privlib = VMS::Filespec::unixify($privlib);
+ $archlib = VMS::Filespec::unixify($archlib);
+}
+my @trypod = (
+ "$archlib/pod/perldiag.pod",
+ "$privlib/pod/perldiag-$Config{version}.pod",
+ "$privlib/pod/perldiag.pod",
+ "$archlib/pods/perldiag.pod",
+ "$privlib/pods/perldiag-$Config{version}.pod",
+ "$privlib/pods/perldiag.pod",
+ );
+# handy for development testing of new warnings etc
+unshift @trypod, "./pod/perldiag.pod" if -e "pod/perldiag.pod";
+(my $PODFILE) = ((grep { -e } @trypod), $trypod[$#trypod])[0];
+
+if ($^O eq 'MacOS') {
+ # just updir one from each lib dir, we'll find it ...
+ ($PODFILE) = grep { -e } map { "$_:pod:perldiag.pod" } @INC;
+}
+
+
$DEBUG ||= 0;
my $WHOAMI = ref bless []; # nobody's business, prolly not even mine
-$OUTPUT_AUTOFLUSH = 1;
+local $| = 1;
+my $_;
-local $_;
+my $standalone;
+my(%HTML_2_Troff, %HTML_2_Latin_1, %HTML_2_ASCII_7);
CONFIG: {
- $opt_p = $opt_d = $opt_v = $opt_f = '';
- %HTML_2_Troff = %HTML_2_Latin_1 = %HTML_2_ASCII_7 = ();
- %exact_duplicate = ();
+ our $opt_p = our $opt_d = our $opt_v = our $opt_f = '';
- unless (caller) {
+ unless (caller) {
$standalone++;
require Getopt::Std;
- Getopt::Std::getopts('pdvf:') || die "Usage: $0 [-v] [-p] [-f splainpod]";
+ Getopt::Std::getopts('pdvf:')
+ or die "Usage: $0 [-v] [-p] [-f splainpod]";
$PODFILE = $opt_f if $opt_f;
$DEBUG = 2 if $opt_d;
$VERBOSE = $opt_v;
$PRETTY = $opt_p;
- }
+ }
if (open(POD_DIAG, $PODFILE)) {
warn "Happy happy podfile from real $PODFILE\n" if $DEBUG;
if (caller) {
INCPATH: {
- for $file ( (map { "$_/$WHOAMI.pm" } @INC), $0) {
+ for my $file ( (map { "$_/$WHOAMI.pm" } @INC), $0) {
warn "Checking $file\n" if $DEBUG;
if (open(POD_DIAG, $file)) {
while (<POD_DIAG>) {
- next unless /^__END__\s*# wish diag dbase were more accessible/;
+ next unless
+ /^__END__\s*# wish diag dbase were more accessible/;
print STDERR "podfile is $file\n" if $DEBUG;
last INCPATH;
}
# etc
);
+our %HTML_Escapes;
*HTML_Escapes = do {
if ($standalone) {
$PRETTY ? \%HTML_2_Latin_1 : \%HTML_2_ASCII_7;
*THITHER = $standalone ? *STDOUT : *STDERR;
-$transmo = <<EOFUNC;
+my %transfmt = ();
+my $transmo = <<EOFUNC;
sub transmo {
- local \$^W = 0; # recursive warnings we do NOT need!
+ #local \$^W = 0; # recursive warnings we do NOT need!
study;
EOFUNC
-### sub finish_compilation { # 5.001e panic: top_level for embedded version
+my %msg;
+{
print STDERR "FINISHING COMPILATION for $_\n" if $DEBUG;
- ### local
- $RS = '';
- local $_;
+ local $/ = '';
+ my $header;
+ my $for_item;
while (<POD_DIAG>) {
- #s/(.*)\n//;
- #$header = $1;
unescape();
if ($PRETTY) {
sub noop { return $_[0] } # spensive for a noop
sub bold { my $str =$_[0]; $str =~ s/(.)/$1\b$1/g; return $str; }
sub italic { my $str = $_[0]; $str =~ s/(.)/_\b$1/g; return $str; }
- s/[BC]<(.*?)>/bold($1)/ges;
+ s/C<<< (.*?) >>>|C<< (.*?) >>|[BC]<(.*?)>/bold($+)/ges;
s/[LIF]<(.*?)>/italic($1)/ges;
} else {
- s/[BC]<(.*?)>/$1/gs;
+ s/C<<< (.*?) >>>|C<< (.*?) >>|[BC]<(.*?)>/$+/gs;
s/[LIF]<(.*?)>/$1/gs;
}
unless (/^=/) {
) )
{
next;
- }
+ }
s/^/ /gm;
$msg{$header} .= $_;
+ undef $for_item;
}
next;
}
- unless ( s/=item (.*)\s*\Z//) {
+ unless ( s/=item (.*?)\s*\z//) {
if ( s/=head1\sDESCRIPTION//) {
$msg{$header = 'DESCRIPTION'} = '';
+ undef $for_item;
}
+ elsif( s/^=for\s+diagnostics\s*\n(.*?)\s*\z// ) {
+ $for_item = $1;
+ }
next;
}
- $header = $1;
-
- if ($header =~ /%[sd]/) {
- $rhs = $lhs = $header;
- #if ($lhs =~ s/(.*?)%d(?!%d)(.*)/\Q$1\E\\d+\Q$2\E\$/g) {
- if ($lhs =~ s/(.*?)%d(?!%d)(.*)/\Q$1\E\\d+\Q$2\E/g) {
- $lhs =~ s/\\%s/.*?/g;
- } else {
- # if i had lookbehind negations, i wouldn't have to do this \377 noise
- $lhs =~ s/(.*?)%s/\Q$1\E.*?\377/g;
- #$lhs =~ s/\377([^\377]*)$/\Q$1\E\$/;
- $lhs =~ s/\377([^\377]*)$/\Q$1\E/;
- $lhs =~ s/\377//g;
- }
- $transmo .= " s{^$lhs}\n {\Q$rhs\E}\n\t&& return 1;\n";
+
+ if( $for_item ) { $header = $for_item; undef $for_item }
+ else {
+ $header = $1;
+ while( $header =~ /[;,]\z/ ) {
+ <POD_DIAG> =~ /^\s*(.*?)\s*\z/;
+ $header .= ' '.$1;
+ }
+ }
+
+ # strip formatting directives from =item line
+ $header =~ s/[A-Z]<(.*?)>/$1/g;
+
+ my @toks = split( /(%l?[dx]|%c|%(?:\.\d+)?s)/, $header );
+ if (@toks > 1) {
+ my $conlen = 0;
+ for my $i (0..$#toks){
+ if( $i % 2 ){
+ if( $toks[$i] eq '%c' ){
+ $toks[$i] = '.';
+ } elsif( $toks[$i] eq '%d' ){
+ $toks[$i] = '\d+';
+ } elsif( $toks[$i] eq '%s' ){
+ $toks[$i] = $i == $#toks ? '.*' : '.*?';
+ } elsif( $toks[$i] =~ '%.(\d+)s' ){
+ $toks[$i] = ".{$1}";
+ } elsif( $toks[$i] =~ '^%l*x$' ){
+ $toks[$i] = '[\da-f]+';
+ }
+ } elsif( length( $toks[$i] ) ){
+ $toks[$i] = quotemeta $toks[$i];
+ $conlen += length( $toks[$i] );
+ }
+ }
+ my $lhs = join( '', @toks );
+ $transfmt{$header}{pat} =
+ " s{^$lhs}\n {\Q$header\E}s\n\t&& return 1;\n";
+ $transfmt{$header}{len} = $conlen;
} else {
- $transmo .= " m{^\Q$header\E} && return 1;\n";
+ $transfmt{$header}{pat} =
+ " m{^\Q$header\E} && return 1;\n";
+ $transfmt{$header}{len} = length( $header );
}
- print STDERR "Already saw $header" if $msg{$header};
+ print STDERR "$WHOAMI: Duplicate entry: \"$header\"\n"
+ if $msg{$header};
$msg{$header} = '';
}
die "No diagnostics?" unless %msg;
+ # Apply patterns in order of decreasing sum of lengths of fixed parts
+ # Seems the best way of hitting the right one.
+ for my $hdr ( sort { $transfmt{$b}{len} <=> $transfmt{$a}{len} }
+ keys %transfmt ){
+ $transmo .= $transfmt{$hdr}{pat};
+ }
$transmo .= " return 0;\n}\n";
print STDERR $transmo if $DEBUG;
eval $transmo;
die $@ if $@;
- $RS = "\n";
-### }
+}
if ($standalone) {
if (!@ARGV and -t STDIN) { print STDERR "$0: Reading from STDIN\n" }
- while ($error = <>) {
+ while (defined (my $error = <>)) {
splainthis($error) || print THITHER $error;
}
exit;
-} else {
- $old_w = 0; $oldwarn = ''; $olddie = '';
-}
+}
+
+my $olddie;
+my $oldwarn;
sub import {
shift;
- $old_w = $^W;
- $^W = 1; # yup, clobbered the global variable; tough, if you
- # want diags, you want diags.
- return if $SIG{__WARN__} eq \&warn_trap;
+ $^W = 1; # yup, clobbered the global variable;
+ # tough, if you want diags, you want diags.
+ return if defined $SIG{__WARN__} && ($SIG{__WARN__} eq \&warn_trap);
for (@_) {
$PRETTY++;
next;
};
+ # matches trace and traceonly for legacy doc mixup reasons
+ /^-t(race(only)?)?$/ && do {
+ $TRACEONLY++;
+ next;
+ };
+ /^-w(arntrace)?$/ && do {
+ $WARNTRACE++;
+ next;
+ };
warn "Unknown flag: $_";
}
sub disable {
shift;
- $^W = $old_w;
return unless $SIG{__WARN__} eq \&warn_trap;
- $SIG{__WARN__} = $oldwarn;
- $SIG{__DIE__} = $olddie;
+ $SIG{__WARN__} = $oldwarn || '';
+ $SIG{__DIE__} = $olddie || '';
}
sub warn_trap {
my $warning = $_[0];
if (caller eq $WHOAMI or !splainthis($warning)) {
- print STDERR $warning;
+ if ($WARNTRACE) {
+ print STDERR Carp::longmess($warning);
+ } else {
+ print STDERR $warning;
+ }
}
- &$oldwarn if defined $oldwarn and $oldwarn and $oldwarn ne \&warn_trap;
+ goto &$oldwarn if defined $oldwarn and $oldwarn and $oldwarn ne \&warn_trap;
};
sub death_trap {
my $exception = $_[0];
- splainthis($exception);
+
+ # See if we are coming from anywhere within an eval. If so we don't
+ # want to explain the exception because it's going to get caught.
+ my $in_eval = 0;
+ my $i = 0;
+ while (my $caller = (caller($i++))[3]) {
+ if ($caller eq '(eval)') {
+ $in_eval = 1;
+ last;
+ }
+ }
+
+ splainthis($exception) unless $in_eval;
if (caller eq $WHOAMI) { print STDERR "INTERNAL EXCEPTION: $exception"; }
&$olddie if defined $olddie and $olddie and $olddie ne \&death_trap;
+
+ return if $in_eval;
+
+ # We don't want to unset these if we're coming from an eval because
+ # then we've turned off diagnostics.
+
+ # Switch off our die/warn handlers so we don't wind up in our own
+ # traps.
$SIG{__DIE__} = $SIG{__WARN__} = '';
+
+ # Have carp skip over death_trap() when showing the stack trace.
local($Carp::CarpLevel) = 1;
+
confess "Uncaught exception from user code:\n\t$exception";
# up we go; where we stop, nobody knows, but i think we die now
# but i'm deeply afraid of the &$olddie guy reraising and us getting
# into an indirect recursion loop
};
+my %exact_duplicate;
+my %old_diag;
+my $count;
+my $wantspace;
sub splainthis {
- local $_ = shift;
+ return 0 if $TRACEONLY;
+ $_ = shift;
+ local $\;
+ local $!;
### &finish_compilation unless %msg;
s/\.?\n+$//;
my $orig = $_;
# return unless defined;
- if ($exact_duplicate{$_}++) {
- return 1;
- }
+
+ # get rid of the where-are-we-in-input part
s/, <.*?> (?:line|chunk).*$//;
- $real = s/(.*?) at .*? (?:line|chunk) \d+.*/$1/;
+
+ # Discard 1st " at <file> line <no>" and all text beyond
+ # but be aware of messsages containing " at this-or-that"
+ my $real = 0;
+ my @secs = split( / at / );
+ return unless @secs;
+ $_ = $secs[0];
+ for my $i ( 1..$#secs ){
+ if( $secs[$i] =~ /.+? (?:line|chunk) \d+/ ){
+ $real = 1;
+ last;
+ } else {
+ $_ .= ' at ' . $secs[$i];
+ }
+ }
+
+ # remove parenthesis occurring at the end of some messages
s/^\((.*)\)$/$1/;
- return 0 unless &transmo;
+
+ if ($exact_duplicate{$orig}++) {
+ return &transmo;
+ } else {
+ return 0 unless &transmo;
+ }
+
$orig = shorten($orig);
if ($old_diag{$_}) {
autodescribe();
exists $HTML_Escapes{$1}
? do { $HTML_Escapes{$1} }
: do {
- warn "Unknown escape: $& in $_";
+ warn "Unknown escape: E<$1> in $_";
"E<$1>";
}
}
sub shorten {
my $line = $_[0];
- if (length $line > 79) {
+ if (length($line) > 79 and index($line, "\n") == -1) {
my $space_place = rindex($line, ' ', 79);
if ($space_place != -1) {
substr($line, $space_place, 1) = "\n\t";
}
-# have to do this: RS isn't set until run time, but we're executing at compile time
-$RS = "\n";
-
1 unless $standalone; # or it'll complain about itself
__END__ # wish diag dbase were more accessible