perldb.pl

早期freebsd实现

package DB;

# modified Perl debugger, to be run from Emacs in perldb-mode
# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
# Johan Vromans -- upgrade to 4.0 pl 10

$header = '$RCSfile: perldb.pl,v $$Revision: 4.0.1.3 $$Date: 92/06/08 13:43:57 $';
#
# This file is automatically included if you do perl -d.
# It's probably not useful to include this yourself.
#
# Perl supplies the values for @line and %sub.  It effectively inserts
# a do DB'DB(<linenum>); in front of every place that can
# have a breakpoint.  It also inserts a do 'perldb.pl' before the first line.
#
# $Log:	perldb.pl,v $
# Revision 4.0.1.3  92/06/08  13:43:57  lwall
# patch20: support for MSDOS folded into perldb.pl
# patch20: perldb couldn't debug file containing '-', such as STDIN designator
# 
# Revision 4.0.1.2  91/11/05  17:55:58  lwall
# patch11: perldb.pl modified to run within emacs in perldb-mode
# 
# Revision 4.0.1.1  91/06/07  11:17:44  lwall
# patch4: added $^P variable to control calling of perldb routines
# patch4: debugger sometimes listed wrong number of lines for a statement
# 
# Revision 4.0  91/03/20  01:25:50  lwall
# 4.0 baseline.
# 
# Revision 3.0.1.6  91/01/11  18:08:58  lwall
# patch42: @_ couldn't be accessed from debugger
# 
# Revision 3.0.1.5  90/11/10  01:40:26  lwall
# patch38: the debugger wouldn't stop correctly or do action routines
# 
# Revision 3.0.1.4  90/10/15  17:40:38  lwall
# patch29: added caller
# patch29: the debugger now understands packages and evals
# patch29: scripts now run at almost full speed under the debugger
# patch29: more variables are settable from debugger
# 
# Revision 3.0.1.3  90/08/09  04:00:58  lwall
# patch19: debugger now allows continuation lines
# patch19: debugger can now dump lists of variables
# patch19: debugger can now add aliases easily from prompt
# 
# Revision 3.0.1.2  90/03/12  16:39:39  lwall
# patch13: perl -d didn't format stack traces of *foo right
# patch13: perl -d wiped out scalar return values of subroutines
# 
# Revision 3.0.1.1  89/10/26  23:14:02  lwall
# patch1: RCS expanded an unintended $Header in lib/perldb.pl
# 
# Revision 3.0  89/10/18  15:19:46  lwall
# 3.0 baseline
# 
# Revision 2.0  88/06/05  00:09:45  root
# Baseline version 2.0.
# 
#

if (-e "/dev/tty") {
    $console = "/dev/tty";
    $rcfile=".perldb";
}
else {
    $console = "con";
    $rcfile="perldb.ini";
}

open(IN, "<$console") || open(IN,  "<&STDIN");	# so we don't dingle stdin
open(OUT,">$console") || open(OUT, ">&STDOUT");	# so we don't dongle stdout
select(OUT);
$| = 1;				# for DB'OUT
select(STDOUT);
$| = 1;				# for real STDOUT
$sub = '';

# Is Perl being run from Emacs?
$emacs = $main'ARGV[$[] eq '-emacs';
shift(@main'ARGV) if $emacs;

$header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
print OUT "\nLoading DB routines from $header\n";
print OUT ("Emacs support ",
	   $emacs ? "enabled" : "available",
	   ".\n");
print OUT "\nEnter h for help.\n\n";

sub DB {
    &save;
    ($package, $filename, $line) = caller;
    $usercontext = '($@, $!, $[, $,, $/, $\) = @saved;' .
	"package $package;";		# this won't let them modify, alas
    local($^P) = 0;			# don't debug our own evals
    local(*dbline) = "_<$filename";
    $max = $#dbline;
    if (($stop,$action) = split(/\0/,$dbline{$line})) {
	if ($stop eq '1') {
	    $signal |= 1;
	}
	else {
	    $evalarg = "\$DB'signal |= do {$stop;}"; &eval;
	    $dbline{$line} =~ s/;9($|\0)/$1/;
	}
    }
    if ($single || $trace || $signal) {
	if ($emacs) {
	    print OUT "\032\032$filename:$line:0\n";
	} else {
	    print OUT "$package'" unless $sub =~ /'/;
	    print OUT "$sub($filename:$line):\t",$dbline[$line];
	    for ($i = $line + 1; $i <= $max && $dbline[$i] == 0; ++$i) {
		last if $dbline[$i] =~ /^\s*(}|#|\n)/;
		print OUT "$sub($filename:$i):\t",$dbline[$i];
	    }
	}
    }
    $evalarg = $action, &eval if $action;
    if ($single || $signal) {
	$evalarg = $pre, &eval if $pre;
	print OUT $#stack . " levels deep in subroutine calls!\n"
	    if $single & 4;
	$start = $line;
      CMD:
	while ((print OUT "  DB<", $#hist+1, "> "), $cmd=&gets) {
	    {
		$single = 0;
		$signal = 0;
		$cmd eq '' && exit 0;
		chop($cmd);
		$cmd =~ s/\\$// && do {
		    print OUT "  cont: ";
		    $cmd .= &gets;
		    redo CMD;
		};
		$cmd =~ /^q$/ && exit 0;
		$cmd =~ /^$/ && ($cmd = $laststep);
		push(@hist,$cmd) if length($cmd) > 1;
		($i) = split(/\s+/,$cmd);
		eval "\$cmd =~ $alias{$i}", print OUT $@ if $alias{$i};
		$cmd =~ /^h$/ && do {
		    print OUT "
T		Stack trace.
s		Single step.
n		Next, steps over subroutine calls.
r		Return from current subroutine.
c [line]	Continue; optionally inserts a one-time-only breakpoint 
		at the specified line.
<CR>		Repeat last n or s.
l min+incr	List incr+1 lines starting at min.
l min-max	List lines.
l line		List line;
l		List next window.
-		List previous window.
w line		List window around line.
l subname	List subroutine.
f filename	Switch to filename.
/pattern/	Search forwards for pattern; final / is optional.
?pattern?	Search backwards for pattern.
L		List breakpoints and actions.
S		List subroutine names.
t		Toggle trace mode.
b [line] [condition]
		Set breakpoint; line defaults to the current execution line; 
		condition breaks if it evaluates to true, defaults to \'1\'.
b subname [condition]
		Set breakpoint at first line of subroutine.
d [line]	Delete breakpoint.
D		Delete all breakpoints.
a [line] command
		Set an action to be done before the line is executed.
		Sequence is: check for breakpoint, print line if necessary,
		do action, prompt user if breakpoint or step, evaluate line.
A		Delete all actions.
V [pkg [vars]]	List some (default all) variables in package (default current).
X [vars]	Same as \"V currentpackage [vars]\".
< command	Define command before prompt.
> command	Define command after prompt.
! number	Redo command (default previous command).
! -number	Redo number\'th to last command.
H -number	Display last number commands (default all).
q or ^D		Quit.
p expr		Same as \"print DB'OUT expr\" in current package.
= [alias value]	Define a command alias, or list current aliases.
command		Execute as a perl statement in current package.

";
		    next CMD; };
		$cmd =~ /^t$/ && do {
		    $trace = !$trace;
		    print OUT "Trace = ".($trace?"on":"off")."\n";
		    next CMD; };
		$cmd =~ /^S$/ && do {
		    foreach $subname (sort(keys %sub)) {
			print OUT $subname,"\n";
		    }
		    next CMD; };
		$cmd =~ s/^X\b/V $package/;
		$cmd =~ /^V$/ && do {
		    $cmd = 'V $package'; };
		$cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
		    $packname = $1;
		    @vars = split(' ',$2);
		    do 'dumpvar.pl' unless defined &main'dumpvar;
		    if (defined &main'dumpvar) {
			&main'dumpvar($packname,@vars);
		    }
		    else {
			print DB'OUT "dumpvar.pl not available.\n";
		    }
		    next CMD; };
		$cmd =~ /^f\b\s*(.*)/ && do {
		    $file = $1;
		    if (!$file) {
			print OUT "The old f command is now the r command.\n";
			print OUT "The new f command switches filenames.\n";
			next CMD;
		    }
		    if (!defined $_main{'_<' . $file}) {
			if (($try) = grep(m#^_<.*$file#, keys %_main)) {
			    $file = substr($try,2);
			    print "\n$file:\n";
			}
		    }
		    if (!defined $_main{'_<' . $file}) {
			print OUT "There's no code here anything matching $file.\n";
			next CMD;
		    }
		    elsif ($file ne $filename) {
			*dbline = "_<$file";
			$max = $#dbline;
			$filename = $file;
			$start = 1;
			$cmd = "l";
		    } };
		$cmd =~ /^l\b\s*(['A-Za-z_]['\w]*)/ && do {
		    $subname = $1;
		    $subname = "main'" . $subname unless $subname =~ /'/;
		    $subname = "main" . $subname if substr($subname,0,1) eq "'";
		    ($file,$subrange) = split(/:/,$sub{$subname});
		    if ($file ne $filename) {
			*dbline = "_<$file";
			$max = $#dbline;
			$filename = $file;
		    }
		    if ($subrange) {
			if (eval($subrange) < -$window) {
			    $subrange =~ s/-.*/+/;
			}
			$cmd = "l $subrange";
		    } else {
			print OUT "Subroutine $1 not found.\n";
			next CMD;
		    } };
		$cmd =~ /^w\b\s*(\d*)$/ && do {
		    $incr = $window - 1;
		    $start = $1 if $1;
		    $start -= $preview;
		    $cmd = 'l ' . $start . '-' . ($start + $incr); };
		$cmd =~ /^-$/ && do {
		    $incr = $window - 1;
		    $cmd = 'l ' . ($start-$window*2) . '+'; };
		$cmd =~ /^l$/ && do {
		    $incr = $window - 1;
		    $cmd = 'l ' . $start . '-' . ($start + $incr); };
		$cmd =~ /^l\b\s*(\d*)\+(\d*)$/ && do {
		    $start = $1 if $1;
		    $incr = $2;
		    $incr = $window - 1 unless $incr;
		    $cmd = 'l ' . $start . '-' . ($start + $incr); };
		$cmd =~ /^l\b\s*(([\d\$\.]+)([-,]([\d\$\.]+))?)?/ && do {
		    $end = (!$2) ? $max : ($4 ? $4 : $2);
		    $end = $max if $end > $max;
		    $i = $2;
		    $i = $line if $i eq '.';
		    $i = 1 if $i < 1;
		    if ($emacs) {
			print OUT "\032\032$filename:$i:0\n";
			$i = $end;
		    } else {
			for (; $i <= $end; $i++) {
			    print OUT "$i:\t", $dbline[$i];
			    last if $signal;
			}
		    }
		    $start = $i;	# remember in case they want more
		    $start = $max if $start > $max;
		    next CMD; };
		$cmd =~ /^D$/ && do {
		    print OUT "Deleting all breakpoints...\n";
		    for ($i = 1; $i <= $max ; $i++) {
			if (defined $dbline{$i}) {
			    $dbline{$i} =~ s/^[^\0]+//;
			    if ($dbline{$i} =~ s/^\0?$//) {
				delete $dbline{$i};
			    }