534 lines
14 KiB
Perl
Executable File
534 lines
14 KiB
Perl
Executable File
package diagnostics;
|
|
|
|
=head1 NAME
|
|
|
|
diagnostics - Perl compiler pragma to force verbose warning diagnostics
|
|
|
|
splain - standalone program to do the same thing
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
As a pragma:
|
|
|
|
use diagnostics;
|
|
use diagnostics -verbose;
|
|
|
|
enable diagnostics;
|
|
disable diagnostics;
|
|
|
|
Aa a program:
|
|
|
|
perl program 2>diag.out
|
|
splain [-v] [-p] diag.out
|
|
|
|
|
|
=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 with the more
|
|
explicative and endearing descriptions found in L<perldiag>. Like the
|
|
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
|
|
|
|
use diagnostics;
|
|
|
|
at the start (or near the start) of your program. (Note
|
|
that this I<does> enable perl's B<-w> flag.) Your whole
|
|
compilation will then be subject(ed :-) to the enhanced diagnostics.
|
|
These still go out B<STDERR>.
|
|
|
|
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
|
|
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 variable can generate nicer
|
|
escape sequences for pagers.
|
|
|
|
=head2 The I<splain> Program
|
|
|
|
While apparently a whole nuther program, I<splain> is actually nothing
|
|
more than a link to the (executable) F<diagnostics.pm> module, as well as
|
|
a link to the F<diagnostics.pod> documentation. The B<-v> flag is like
|
|
the C<use diagnostics -verbose> directive.
|
|
The B<-p> flag is like the
|
|
$diagnostics::PRETTY variable. Since you're post-processing with
|
|
I<splain>, there's no sense in being able to enable() or disable() processing.
|
|
|
|
Output from I<splain> is directed to B<STDOUT>, unlike the pragma.
|
|
|
|
=head1 EXAMPLES
|
|
|
|
The following file is certain to trigger a few errors at both
|
|
runtime and compiletime:
|
|
|
|
use diagnostics;
|
|
print NOWHERE "nothing\n";
|
|
print STDERR "\n\tThis message should be unadorned.\n";
|
|
warn "\tThis is a user warning";
|
|
print "\nDIAGNOSTIC TESTER: Please enter a <CR> here: ";
|
|
my $a, $b = scalar <STDIN>;
|
|
print "\n";
|
|
print $x/$y;
|
|
|
|
If you prefer to run your program first and look at its problem
|
|
afterwards, do this:
|
|
|
|
perl -w test.pl 2>test.out
|
|
./splain < test.out
|
|
|
|
Note that this is not in general possible in shells of more dubious heritage,
|
|
as the theoretical
|
|
|
|
(perl -w test.pl >/dev/tty) >& test.out
|
|
./splain < test.out
|
|
|
|
Because you just moved the existing B<stdout> to somewhere else.
|
|
|
|
If you don't want to modify your source code, but still have on-the-fly
|
|
warnings, do this:
|
|
|
|
exec 3>&1; perl -w test.pl 2>&1 1>&3 3>&- | splain 1>&2 3>&-
|
|
|
|
Nifty, eh?
|
|
|
|
If you want to control warnings on the fly, do something like this.
|
|
Make sure you do the C<use> first, or you won't be able to get
|
|
at the enable() or disable() methods.
|
|
|
|
use diagnostics; # checks entire compilation phase
|
|
print "\ntime for 1st bogus diags: SQUAWKINGS\n";
|
|
print BOGUS1 'nada';
|
|
print "done with 1st bogus\n";
|
|
|
|
disable diagnostics; # only turns off runtime warnings
|
|
print "\ntime for 2nd bogus: (squelched)\n";
|
|
print BOGUS2 'nada';
|
|
print "done with 2nd bogus\n";
|
|
|
|
enable diagnostics; # turns back on runtime warnings
|
|
print "\ntime for 3rd bogus: SQUAWKINGS\n";
|
|
print BOGUS3 'nada';
|
|
print "done with 3rd bogus\n";
|
|
|
|
disable diagnostics;
|
|
print "\ntime for 4th bogus: (squelched)\n";
|
|
print BOGUS4 'nada';
|
|
print "done with 4th bogus\n";
|
|
|
|
=head1 INTERNALS
|
|
|
|
Diagnostic messages derive from the F<perldiag.pod> file when available at
|
|
runtime. Otherwise, they may be embedded in the file itself when the
|
|
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 diagnostics::splainthis() function
|
|
(the module's $SIG{__WARN__} interceptor) has had its way with your
|
|
warnings.
|
|
|
|
There is a $diagnostics::DEBUG variable you may set if you're desperately
|
|
curious what sorts of things are being intercepted.
|
|
|
|
BEGIN { $diagnostics::DEBUG = 1 }
|
|
|
|
|
|
=head1 BUGS
|
|
|
|
Not being able to say "no diagnostics" is annoying, but may not be
|
|
insurmountable.
|
|
|
|
The C<-pretty> directive is called too late to affect matters.
|
|
You have to do this instead, and I<before> you load the module.
|
|
|
|
BEGIN { $diagnostics::PRETTY = 1 }
|
|
|
|
I could start up faster by delaying compilation until it should be
|
|
needed, but this gets a "panic: top_level" when using the pragma form
|
|
in Perl 5.001e.
|
|
|
|
While it's true that this documentation is somewhat subserious, if you use
|
|
a program named I<splain>, you should expect a bit of whimsy.
|
|
|
|
=head1 AUTHOR
|
|
|
|
Tom Christiansen <F<tchrist@mox.perl.com>>, 25 June 1995.
|
|
|
|
=cut
|
|
|
|
require 5.001;
|
|
use Carp;
|
|
|
|
use Config;
|
|
($privlib, $archlib) = @Config{qw(privlibexp archlibexp)};
|
|
if ($^O eq 'VMS') {
|
|
require VMS::Filespec;
|
|
$privlib = VMS::Filespec::unixify($privlib);
|
|
$archlib = VMS::Filespec::unixify($archlib);
|
|
}
|
|
@trypod = ("$archlib/pod/perldiag.pod",
|
|
"$privlib/pod/perldiag-$].pod",
|
|
"$privlib/pod/perldiag.pod");
|
|
# handy for development testing of new warnings etc
|
|
unshift @trypod, "./pod/perldiag.pod" if -e "pod/perldiag.pod";
|
|
($PODFILE) = ((grep { -e } @trypod), $trypod[$#trypod])[0];
|
|
|
|
$DEBUG ||= 0;
|
|
my $WHOAMI = ref bless []; # nobody's business, prolly not even mine
|
|
|
|
$| = 1;
|
|
|
|
local $_;
|
|
|
|
CONFIG: {
|
|
$opt_p = $opt_d = $opt_v = $opt_f = '';
|
|
%HTML_2_Troff = %HTML_2_Latin_1 = %HTML_2_ASCII_7 = ();
|
|
%exact_duplicate = ();
|
|
|
|
unless (caller) {
|
|
$standalone++;
|
|
require Getopt::Std;
|
|
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;
|
|
last CONFIG;
|
|
}
|
|
|
|
if (caller) {
|
|
INCPATH: {
|
|
for $file ( (map { "$_/$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/;
|
|
print STDERR "podfile is $file\n" if $DEBUG;
|
|
last INCPATH;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
print STDERR "podfile is <DATA>\n" if $DEBUG;
|
|
*POD_DIAG = *main::DATA;
|
|
}
|
|
}
|
|
if (eof(POD_DIAG)) {
|
|
die "couldn't find diagnostic data in $PODFILE @INC $0";
|
|
}
|
|
|
|
|
|
%HTML_2_Troff = (
|
|
'amp' => '&', # ampersand
|
|
'lt' => '<', # left chevron, less-than
|
|
'gt' => '>', # right chevron, greater-than
|
|
'quot' => '"', # double quote
|
|
|
|
"Aacute" => "A\\*'", # capital A, acute accent
|
|
# etc
|
|
|
|
);
|
|
|
|
%HTML_2_Latin_1 = (
|
|
'amp' => '&', # ampersand
|
|
'lt' => '<', # left chevron, less-than
|
|
'gt' => '>', # right chevron, greater-than
|
|
'quot' => '"', # double quote
|
|
|
|
"Aacute" => "\xC1" # capital A, acute accent
|
|
|
|
# etc
|
|
);
|
|
|
|
%HTML_2_ASCII_7 = (
|
|
'amp' => '&', # ampersand
|
|
'lt' => '<', # left chevron, less-than
|
|
'gt' => '>', # right chevron, greater-than
|
|
'quot' => '"', # double quote
|
|
|
|
"Aacute" => "A" # capital A, acute accent
|
|
# etc
|
|
);
|
|
|
|
*HTML_Escapes = do {
|
|
if ($standalone) {
|
|
$PRETTY ? \%HTML_2_Latin_1 : \%HTML_2_ASCII_7;
|
|
} else {
|
|
\%HTML_2_Latin_1;
|
|
}
|
|
};
|
|
|
|
*THITHER = $standalone ? *STDOUT : *STDERR;
|
|
|
|
$transmo = <<EOFUNC;
|
|
sub transmo {
|
|
local \$^W = 0; # recursive warnings we do NOT need!
|
|
study;
|
|
EOFUNC
|
|
|
|
### sub finish_compilation { # 5.001e panic: top_level for embedded version
|
|
print STDERR "FINISHING COMPILATION for $_\n" if $DEBUG;
|
|
### local
|
|
$RS = '';
|
|
local $_;
|
|
while (<POD_DIAG>) {
|
|
#s/(.*)\n//;
|
|
#$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/[LIF]<(.*?)>/italic($1)/ges;
|
|
} else {
|
|
s/[BC]<(.*?)>/$1/gs;
|
|
s/[LIF]<(.*?)>/$1/gs;
|
|
}
|
|
unless (/^=/) {
|
|
if (defined $header) {
|
|
if ( $header eq 'DESCRIPTION' &&
|
|
( /Optional warnings are enabled/
|
|
|| /Some of these messages are generic./
|
|
) )
|
|
{
|
|
next;
|
|
}
|
|
s/^/ /gm;
|
|
$msg{$header} .= $_;
|
|
}
|
|
next;
|
|
}
|
|
unless ( s/=item (.*)\s*\Z//) {
|
|
|
|
if ( s/=head1\sDESCRIPTION//) {
|
|
$msg{$header = 'DESCRIPTION'} = '';
|
|
}
|
|
next;
|
|
}
|
|
|
|
# strip formatting directives in =item line
|
|
($header = $1) =~ s/[A-Z]<(.*?)>/$1/g;
|
|
|
|
if ($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;
|
|
$lhs =~ s/\.\*\?$/.*/; # Allow %s at the end to eat it all
|
|
}
|
|
$transmo .= " s{^$lhs}\n {\Q$rhs\E}s\n\t&& return 1;\n";
|
|
} else {
|
|
$transmo .= " m{^\Q$header\E} && return 1;\n";
|
|
}
|
|
|
|
print STDERR "$WHOAMI: Duplicate entry: \"$header\"\n"
|
|
if $msg{$header};
|
|
|
|
$msg{$header} = '';
|
|
}
|
|
|
|
|
|
close POD_DIAG unless *main::DATA eq *POD_DIAG;
|
|
|
|
die "No diagnostics?" unless %msg;
|
|
|
|
$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 "$0: Reading from STDIN\n" }
|
|
while (defined ($error = <>)) {
|
|
splainthis($error) || print THITHER $error;
|
|
}
|
|
exit;
|
|
} else {
|
|
$old_w = 0; $oldwarn = ''; $olddie = '';
|
|
}
|
|
|
|
sub import {
|
|
shift;
|
|
$old_w = $^W;
|
|
$^W = 1; # yup, clobbered the global variable; tough, if you
|
|
# want diags, you want diags.
|
|
return if $SIG{__WARN__} eq \&warn_trap;
|
|
|
|
for (@_) {
|
|
|
|
/^-d(ebug)?$/ && do {
|
|
$DEBUG++;
|
|
next;
|
|
};
|
|
|
|
/^-v(erbose)?$/ && do {
|
|
$VERBOSE++;
|
|
next;
|
|
};
|
|
|
|
/^-p(retty)?$/ && do {
|
|
print STDERR "$0: I'm afraid it's too late for prettiness.\n";
|
|
$PRETTY++;
|
|
next;
|
|
};
|
|
|
|
warn "Unknown flag: $_";
|
|
}
|
|
|
|
$oldwarn = $SIG{__WARN__};
|
|
$olddie = $SIG{__DIE__};
|
|
$SIG{__WARN__} = \&warn_trap;
|
|
$SIG{__DIE__} = \&death_trap;
|
|
}
|
|
|
|
sub enable { &import }
|
|
|
|
sub disable {
|
|
shift;
|
|
$^W = $old_w;
|
|
return unless $SIG{__WARN__} eq \&warn_trap;
|
|
$SIG{__WARN__} = $oldwarn;
|
|
$SIG{__DIE__} = $olddie;
|
|
}
|
|
|
|
sub warn_trap {
|
|
my $warning = $_[0];
|
|
if (caller eq $WHOAMI or !splainthis($warning)) {
|
|
print STDERR $warning;
|
|
}
|
|
&$oldwarn if defined $oldwarn and $oldwarn and $oldwarn ne \&warn_trap;
|
|
};
|
|
|
|
sub death_trap {
|
|
my $exception = $_[0];
|
|
|
|
# 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 (1) {
|
|
my $caller = (caller($i++))[3] or last;
|
|
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;
|
|
|
|
# We don't want to unset these if we're coming from an eval because
|
|
# then we've turned off diagnostics. (Actually what does this next
|
|
# line do? -PSeibel)
|
|
$SIG{__DIE__} = $SIG{__WARN__} = '' unless $in_eval;
|
|
local($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
|
|
};
|
|
|
|
sub splainthis {
|
|
local $_ = shift;
|
|
local $\;
|
|
### &finish_compilation unless %msg;
|
|
s/\.?\n+$//;
|
|
my $orig = $_;
|
|
# return unless defined;
|
|
if ($exact_duplicate{$_}++) {
|
|
return 1;
|
|
}
|
|
s/, <.*?> (?:line|chunk).*$//;
|
|
$real = s/(.*?) at .*? (?:line|chunk) \d+.*/$1/;
|
|
s/^\((.*)\)$/$1/;
|
|
return 0 unless &transmo;
|
|
$orig = shorten($orig);
|
|
if ($old_diag{$_}) {
|
|
autodescribe();
|
|
print THITHER "$orig (#$old_diag{$_})\n";
|
|
$wantspace = 1;
|
|
} else {
|
|
autodescribe();
|
|
$old_diag{$_} = ++$count;
|
|
print THITHER "\n" if $wantspace;
|
|
$wantspace = 0;
|
|
print THITHER "$orig (#$old_diag{$_})\n";
|
|
if ($msg{$_}) {
|
|
print THITHER $msg{$_};
|
|
} else {
|
|
if (0 and $standalone) {
|
|
print THITHER " **** Error #$old_diag{$_} ",
|
|
($real ? "is" : "appears to be"),
|
|
" an unknown diagnostic message.\n\n";
|
|
}
|
|
return 0;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
sub autodescribe {
|
|
if ($VERBOSE and not $count) {
|
|
print THITHER &{$PRETTY ? \&bold : \&noop}("DESCRIPTION OF DIAGNOSTICS"),
|
|
"\n$msg{DESCRIPTION}\n";
|
|
}
|
|
}
|
|
|
|
sub unescape {
|
|
s {
|
|
E<
|
|
( [A-Za-z]+ )
|
|
>
|
|
} {
|
|
do {
|
|
exists $HTML_Escapes{$1}
|
|
? do { $HTML_Escapes{$1} }
|
|
: do {
|
|
warn "Unknown escape: E<$1> in $_";
|
|
"E<$1>";
|
|
}
|
|
}
|
|
}egx;
|
|
}
|
|
|
|
sub shorten {
|
|
my $line = $_[0];
|
|
if (length($line) > 79 and index($line, "\n") == -1) {
|
|
my $space_place = rindex($line, ' ', 79);
|
|
if ($space_place != -1) {
|
|
substr($line, $space_place, 1) = "\n\t";
|
|
}
|
|
}
|
|
return $line;
|
|
}
|
|
|
|
|
|
# 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
|