#!/usr/bin/perl
# $Id: genxref,v 1.5 1998/04/22 12:16:12 pergj Exp $

# genxref.pl --	Finds identifiers in a set of C files using an
#		extremely fuzzy algorithm.  It sort of works.
#
#	Arne Georg Gleditsch <argggh@ifi.uio.no>
#	Per Kristian Gjermshus <pergj@ifi.uio.no>
#
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

# TODO: ns/cmd/xfe/src/MozillaApp.h, XFE_MozillaApp

######################################################################

use lib 'lib/';
use integer;
use DB_File;


%itype = (('macro',	'M'),
	  ('typedef',	'T'),
	  ('struct',	'S'),
	  ('enum',	'E'),
	  ('union',	'U'),
	  ('function',	'F'),
	  ('funcprot',	'f'),
	  ('class',	'C'),	# (C++)
	  ('classforw',	'c'),	# (C++)
	  ('var',	'V'));
#         ('reference', 'R')

@reserved = ('auto', 'break', 'case', 'char', 'const', 'continue',
	     'default', 'do', 'double', 'else', 'enum', 'extern',
	     'float', 'for', 'goto', 'if', 'int', 'long', 'register',
	     'return', 'short', 'signed', 'sizeof', 'static',
	     'struct', 'switch', 'typedef', 'union', 'unsigned',
	     'void', 'volatile', 'while', 'fortran', 'asm',
	     'inline', 'operator',
	     'class',		# (C++)
# Her bør vi ha flere av disse: 
	     '__asm__','__inline__');


$ident = '\~?_*[a-zA-Z][a-zA-Z0-9_]*';


$realpath = $ARGV[0];
$realpath ||= '.';
$realpath .= '/';


sub wash {
    my $towash = $_[0];
    $towash =~ s/[^\n]+//gs;
    return($towash);
}

sub stripodd {
    my $tostrip = $_[0];
    while ($tostrip =~ s/\{([^\{\}]*)\}/
	   "\05".&wash($1)/ges) {}
    $tostrip =~ s/\05/\{\}/gs;
    $tostrip =~ s/[\{\}]//gs;
    return($tostrip);
}

sub classes {
    my @c = (shift =~ /($ident)\s*(?:$|,)/gm);
    if (@c) {
	return(join(":", @c)."::");
    } else {
	return('');
    }
}

sub findident {
    print(STDERR "Starting pass 1: Collect identifier definitions.\n");

    $start = time;
    $fnum = 0; $defs = 0;

    foreach $f (@f) {
	$f =~ s/^$realpath//o;
	$fileidx{++$fnum} = $f;

	open(SRCFILE, $realpath.$f);
	$_ = $/; undef($/); $contents = <SRCFILE>; $/ = $_;
	close(SRCFILE);

	print(STDERR 
	      "(Pass 1) $f (",length($contents),
	      "), file $fnum of ",$#f+1,"...\n");

	# Remove comments.
	$contents =~ s/\/\*(.*?)\*\//&wash($1)/ges;
	$contents =~ s/\/\/[^\n]*//g; # C++

	# Unwrap continunation lines.
	$contents =~ s/\\\s*\n/$1\05/gs;
	while ($contents =~ s/\05([^\n\05]+)\05/$1\05\05/gs) {}
	$contents =~ s/(\05+)([^\n]*)/"$2"."\n" x length($1)/gse;

	# Find macro (un)definitions.
	$l = 0;
	foreach ($contents =~ /^(.*)/gm) {
	    $l++;
	    if (/^[ \t]*\#\s*(define|undef)\s+($ident)/o) {
		$xref{$2} .= "$itype{'macro'}$fnum:$l\t";
		$defs++;
	    }
	}

	# We want to do some funky heuristics with preprocessor blocks
	# later, so mark them. (FIXME: #elif)
	$contents =~ s/^[ \t]*\#\s*if.*/\01/gm;
	$contents =~ s/^[ \t]*\#\s*else.*/\02/gm;
	$contents =~ s/^[ \t]*\#\s*endif.*/\03/gm;

	# Strip all preprocessor directives.
	$contents =~ s/^[ \t]*\#(.*)//gm;

	# Now, remove all odd block markers ({,}) we find inside
	# #else..#endif blocks.  (And pray they matched one in the
	# preceding #if..#else block.)
	while ($contents =~ s/\02([^\01\02\03]*\03)/&stripodd($1)/ges ||
	       $contents =~ s/\01([^\01\02\03]*)\03/$1/gs) {}

	while ($contents =~ /([\01\02\03\04\05])/gs) {
	    print(STDERR "\t ** stray ".($1 eq "\01"  
					 ? "#if"
					 : ($1 eq "\02"
					    ? "#else"
					    : ($1 eq "\03"
					       ? "#endif"
					       : "control sequence"
					       )
					    )
					 )." found.\n");
	}
	$contents =~ s/[\01\02\03\04\05]//gs;

	# Remove all but outermost blocks.  (No local variables.)
	while ($contents =~ s/\{([^\{\}]*)\}/
	       "\05".&wash($1)/ges) {}
	$contents =~ s/\05/\{\}/gs;

	# Remove nested parentheses.
	while ($contents =~ s/\(([^\)]*)\(/\($1\05/g ||
	       $contents =~ s/\05([^\(\)]*)\)/ $1 /g) {}
	
	# Some heuristics here: Try to recognize "code" and delete
	# everything up to the next block delimiter.
	# $contents =~ s/([\;\}\{])(\s*$ident\s*\([^\)]*\)[^\{\}]*)/
	# 	"$1".&wash($2)/goes;
	# $contents =~ s/([\;\{])(\s*\**$ident\s*\=[^\{\}]*)/
	# 	"$1".&wash($2)/goes;

	# Parentheses containing commas are probably not interesting.
	$contents =~ s/\(([^\)]*\,[^\)]*)\)/
	    "()".&wash($1)/ges;


	# This operator-stuff messes things up. (C++)
	$contents =~ s/operator[\<\>\=\!\+\-\*\%\/]{1,2}/operator/g;

	# Ranges are uninteresting (and confusing).
	$contents =~ s/\[.*?\]//gs;

	# And so are assignments.
	$contents =~ s/\=(.*?);/";".&wash($1)/ges;

	# From here on, \01 and \02 are used to encapsulate found
	# identifiers,

	# Find struct, enum and union definitions.
	$contents =~ s/((struct|enum|union)\s+($ident|)\s*({}|(;)))/
	    "$2 ".($3 ? "\01".$itype{$2}.$3."\02 " : "").$5.&wash($1)/goes;

	# Find class definitions. (C++)
	$contents =~ s/((class)\s+($ident)\s*(:[^;\{]*|)({}|(;)))/
	    "$2 "."\01".$itype{$2.($6 ? 'forw' : '')}.
		&classes($4).$3."\02 ".$6.&wash($1)/goes;

	@contents = split(/[;\}]/, $contents);
	$contents = '';

	foreach (@contents) {
	    s/^(\s*)(struct|enum|union|inline)/$1/;

	    if (/$ident[^a-zA-Z0-9_]+$ident/) { # It takes two, baby.

		$t = /^\s*typedef/s;	# Is this a type definition?

		s/($ident(?:\s*::\s*$ident|))	# ($1) Match the identifier
		    ([\s\)]*		# ($2) Tokens allowed after identifier
		     (\([^\)]*\)	# ($3) Function parameters?
		      (?:\s*:[^\{]*|)	# inheritage specification (C++)
		      |)		# No function parameters
		     \s*($|,|\{))/	# ($4) Allowed termination chars.
		  "\01".		# identifier marker
		   ($t			# if type definition...
		    ? $itype{'typedef'} # ..mark as such
		    : ($3		# $3 is empty unless function definition.
		       ? ($4 eq '{' 		# Terminating token indicates 
			  ? $itype{'function'} 	# function or
			  : $itype{'funcprot'}) # function prototype.
		       : $itype{'var'}) 	# Variable.
		    )."$1\02 ".&wash($2)/goesx;
	       }

	    $contents .= $_;
	}

	$l = 0; 
	foreach ($contents =~ /^(.*)/gm) {
	    $l++;
	    while (/\01(.)(?:(.+?)\s*::\s*|)($ident)\02/go) {
		$xref{$3} .= "$1$fnum:$l".($2 ? ":$2" : "")."\t";
		$defs++;
	    }
	}
    }

    # Så juksar me litt.
    foreach (@reserved) {
	delete($xref{$_});
    }

    print(STDERR 
	  "Completed pass 1 (",(time-$start),"s):",
	  " $defs definitions found.\n\n");
}	


sub findusage {
    print(STDERR "Starting pass 2: Generate reference statistics.\n");

    $start = time;
    $fnum = 0; $refs = 0;

    foreach $f (@f) {
	$f =~ s/^$realpath//o;
	$fnum++;
	$lcount = 0;
	%tref = ();

	open(SRCFILE, $realpath.$f);
	$_ = $/; undef($/); $contents = <SRCFILE>; $/ = $_;
	close(SRCFILE);

	print(STDERR 
	      "(Pass 2) $f (",length($contents),
	      "), file $fnum of ",$#f+1,"...\n");

	# Remove comments
	$contents =~ s/\/\*(.*?)\*\//&wash($1)/ges; 
	$contents =~ s/\/\/[^\n]*//g;

	# Remove include statements
	$contents =~ s/^[ \t]*\#include[ \t]+[^\n]*//gm;

	# FIXME: "var"

	@lines = split(/\n/, $contents);

	foreach $line (@lines) {
	    $lcount++;
	    foreach ($line =~ /(?:^|[^a-zA-Z_\#])($ident)\b/og) {
		$tref{$_} .= "$lcount," if $xref{$_};
	    }
	}

	while (($a, $b) = each(%tref)) {
	    chop($b);
	    $xref{$a} .= "R$fnum:$b\t";
	    $refs++;
	}
    }
    print(STDERR 
	  "Completed pass 2 (",(time-$start),"s):",
	  "$refs references to known identifiers found.\n\n");
}


sub dumpdb {
    print(STDERR "Starting pass 3: Dump database to disk.\n");

    $start = time;
    tie (%xrefdb, "DB_File" , "xref", O_RDWR|O_CREAT, 0664, $DB_HASH)
	|| die("Could not open \"xref\" for writing");

    $i = 0;
    while (($k, $v) = each(%xref)) {
	$i++;
	delete($xref{$k});
	$xrefdb{$k} = $v;
	unless ($i % 100) {
	    print(STDERR "(Pass 3) identifier $i of maximum $defs...\n");
	}
    }

    untie(%xrefdb);
    print(STDERR 
	  "Completed pass 3 (",(time-$start),"s):",
	  "Information on $i identifiers dumped to disk.\n\n");
}


tie (%fileidx, "DB_File", "fileidx", O_RDWR|O_CREAT, 0664, $DB_HASH)
    || die("Could not open \"fileidx\" for writing");

open(FILES, "find $realpath -print |");
while (<FILES>) {
    chop;
    push(@f, $_) if /\.([ch]|cpp?|cc)$/i; # Duplicated in lib/LXR/Common.pm
}
close(FILES);

&findident;
&findusage;
&dumpdb;

dbmclose(%fileidx);