#!/usr/bin/perl
# Copyright (C) 2016 and later: Unicode, Inc. and others.
# License & terms of use: http://www.unicode.org/copyright.html
# ********************************************************************
# * COPYRIGHT:
# * Copyright (c) 2002-2016, International Business Machines Corporation and
# * others. All Rights Reserved.
# ********************************************************************
#
# regexcst.pl
# Compile the regular expression paser state table data into initialized C data.
# Usage:
# cd icu/source/i18n
# perl regexcst.pl < regexcst.txt > regexcst.h
#
# The output file, regexcst.h, is included by some of the .cpp regex
# implementation files. This perl script is NOT run as part
# of a normal ICU build. It is run by hand when needed, and the
# regexcst.h generated file is put back into cvs.
#
# See regexcst.txt for a description of the input format for this script.
#
# This script is derived from rbbicst.pl, which peforms the same function
# for the Rule Based Break Iterator Rule Parser. Perhaps they could be
# merged?
#
$num_states = 1; # Always the state number for the line being compiled.
$line_num = 0; # The line number in the input file.
$states{"pop"} = 255; # Add the "pop" to the list of defined state names.
# This prevents any state from being labelled with "pop",
# and resolves references to "pop" in the next state field.
line_loop: while (<>) {
chomp();
$line = $_;
@fields = split();
$line_num++;
# Remove # comments, which are any fields beginning with a #, plus all
# that follow on the line.
for ($i=0; $i<@fields; $i++) {
if ($fields[$i] =~ /^#/) {
@fields = @fields[0 .. $i-1];
last;
}
}
# ignore blank lines, and those with no fields left after stripping comments..
if (@fields == 0) {
next;
}
#
# State Label: handling.
# Does the first token end with a ":"? If so, it's the name of a state.
# Put in a hash, together with the current state number,
# so that we can later look up the number from the name.
#
if (@fields[0] =~ /.*:$/) {
$state_name = @fields[0];
$state_name =~ s/://; # strip off the colon from the state name.
if ($states{$state_name} != 0) {
print " rbbicst: at line $line-num duplicate definition of state $state_name\n";
}
$states{$state_name} = $num_states;
$stateNames[$num_states] = $state_name;
# if the label was the only thing on this line, go on to the next line,
# otherwise assume that a state definition is on the same line and fall through.
if (@fields == 1) {
next line_loop;
}
shift @fields; # shift off label field in preparation
# for handling the rest of the line.
}
#
# State Transition line.
# syntax is this,
# character [n] target-state [^push-state] [function-name]
# where
# [something] is an optional something
# character is either a single quoted character e.g. '['
# or a name of a character class, e.g. white_space
#
$state_line_num[$num_states] = $line_num; # remember line number with each state
# so we can make better error messages later.
#
# First field, character class or literal character for this transition.
#
if ($fields[0] =~ /^'.'$/) {
# We've got a quoted literal character.
$state_literal_chars[$num_states] = $fields[0];
$state_literal_chars[$num_states] =~ s/'//g;
} else {
# We've got the name of a character class.
$state_char_class[$num_states] = $fields[0];
if ($fields[0] =~ /[\W]/) {
print " rbbicsts: at line $line_num, bad character literal or character class name.\n";
print " scanning $fields[0]\n";
exit(-1);
}
}
shift @fields;
#
# do the 'n' flag
#
$state_flag[$num_states] = "FALSE";
if ($fields[0] eq "n") {
$state_flag[$num_states] = "TRUE";
shift @fields;
}
#
# do the destination state.
#
$state_dest_state[$num_states] = $fields[0];
if ($fields[0] eq "") {
print " rbbicsts: at line $line_num, destination state missing.\n";
exit(-1);
}
shift @fields;
#
# do the push state, if present.
#
if ($fields[0] =~ /^\^/) {
$fields[0] =~ s/^\^//;
$state_push_state[$num_states] = $fields[0];
if ($fields[0] eq "" ) {
print " rbbicsts: at line $line_num, expected state after ^ (no spaces).\n";
exit(-1);
}
shift @fields;
}
#
# Lastly, do the optional action name.
#
if ($fields[0] ne "") {
$state_func_name[$num_states] = $fields[0];
shift @fields;
}
#
# There should be no fields left on the line at this point.
#
if (@fields > 0) {
print " rbbicsts: at line $line_num, unexpected extra stuff on input line.\n";
print " scanning $fields[0]\n";
}
$num_states++;
}
#
# We've read in the whole file, now go back and output the
# C source code for the state transition table.
#
# We read all states first, before writing anything, so that the state numbers
# for the destination states are all available to be written.
#
#
# Make hashes for the names of the character classes and
# for the names of the actions that appeared.
#
for ($state=1; $state < $num_states; $state++) {
if ($state_char_class[$state] ne "") {
if ($charClasses{$state_char_class[$state]} == 0) {
$charClasses{$state_char_class[$state]} = 1;
}
}
if ($state_func_name[$state] eq "") {
$state_func_name[$state] = "doNOP";
}
if ($actions{$state_action_name[$state]} == 0) {
$actions{$state_func_name[$state]} = 1;
}
}
#
# Check that all of the destination states have been defined
#
#
$states{"exit"} = 0; # Predefined state name, terminates state machine.
for ($state=1; $state<$num_states; $state++) {
if ($states{$state_dest_state[$state]} == 0 && $state_dest_state[$state] ne "exit") {
print "Error at line $state_line_num[$state]: target state \"$state_dest_state[$state]\" is not defined.\n";
$errors++;
}
if ($state_push_state[$state] ne "" && $states{$state_push_state[$state]} == 0) {
print "Error at line $state_line_num[$state]: target state \"$state_push_state[$state]\" is not defined.\n";
$errors++;
}
}
die if ($errors>0);
print "//---------------------------------------------------------------------------------\n";
print "//\n";
print "// Generated Header File. Do not edit by hand.\n";
print "// This file contains the state table for the ICU Regular Expression Pattern Parser\n";
print "// It is generated by the Perl script \"regexcst.pl\" from\n";
print "// the rule parser state definitions file \"regexcst.txt\".\n";
print "//\n";
print "// Copyright (C) 2002-2016 International Business Machines Corporation \n";
print "// and others. All rights reserved. \n";
print "//\n";
print "//---------------------------------------------------------------------------------\n";
print "#ifndef RBBIRPT_H\n";
print "#define RBBIRPT_H\n";
print "\n";
print "#include \"unicode/utypes.h\"\n";
print "\n";
print "U_NAMESPACE_BEGIN\n";
#
# Emit the constants for indicies of Unicode Sets
# Define one constant for each of the character classes encountered.
# At the same time, store the index corresponding to the set name back into hash.
#
print "//\n";
print "// Character classes for regex pattern scanning.\n";
print "//\n";
$i = 128; # State Table values for Unicode char sets range from 128-250.
# Sets "default", "quoted", etc. get special handling.
# They have no corresponding UnicodeSet object in the state machine,
# but are handled by special case code. So we emit no reference
# to a UnicodeSet object to them here.
foreach $setName (keys %charClasses) {
if ($setName eq "default") {
$charClasses{$setName} = 255;}
elsif ($setName eq "quoted") {
$charClasses{$setName} = 254;}
elsif ($setName eq "eof") {
$charClasses{$setName} = 253;}
else {
# Normal character class. Fill in array with a ptr to the corresponding UnicodeSet in the state machine.
print " static const uint8_t kRuleSet_$setName = $i;\n";
$charClasses{$setName} = $i;
$i++;
}
}
print "\n\n";
#
# Emit the enum for the actions to be performed.
#
print "enum Regex_PatternParseAction {\n";
foreach $act (keys %actions) {
print " $act,\n";
}
print " rbbiLastAction};\n\n";
#
# Emit the struct definition for transtion table elements.
#
print "//-------------------------------------------------------------------------------\n";
print "//\n";
print "// RegexTableEl represents the structure of a row in the transition table\n";
print "// for the pattern parser state machine.\n";
print "//-------------------------------------------------------------------------------\n";
print "struct RegexTableEl {\n";
print " Regex_PatternParseAction fAction;\n";
print " uint8_t fCharClass; // 0-127: an individual ASCII character\n";
print " // 128-255: character class index\n";
print " uint8_t fNextState; // 0-250: normal next-state numbers\n";
print " // 255: pop next-state from stack.\n";
print " uint8_t fPushState;\n";
print " UBool fNextChar;\n";
print "};\n\n";
#
# emit the state transition table
#
print "static const struct RegexTableEl gRuleParseStateTable[] = {\n";
print " {doNOP, 0, 0, 0, TRUE}\n"; # State 0 is a dummy. Real states start with index = 1.
for ($state=1; $state < $num_states; $state++) {
print " , {$state_func_name[$state],";
if ($state_literal_chars[$state] ne "") {
$c = $state_literal_chars[$state];
printf(" %d /* $c */,", ord($c)); # use numeric value, so EBCDIC machines are ok.
}else {
print " $charClasses{$state_char_class[$state]},";
}
print " $states{$state_dest_state[$state]},";
# The push-state field is optional. If omitted, fill field with a zero, which flags
# the state machine that there is no push state.
if ($state_push_state[$state] eq "") {
print "0, ";
} else {
print " $states{$state_push_state[$state]},";
}
print " $state_flag[$state]} ";
# Put out a C++ comment showing the number (index) of this state row,
# and, if this is the first row of the table for this state, the state name.
print " // $state ";
if ($stateNames[$state] ne "") {
print " $stateNames[$state]";
}
print "\n";
};
print " };\n";
#
# emit a mapping array from state numbers to state names.
#
# This array is used for producing debugging output from the pattern parser.
#
print "static const char * const RegexStateNames[] = {";
for ($state=0; $state<$num_states; $state++) {
if ($stateNames[$state] ne "") {
print " \"$stateNames[$state]\",\n";
} else {
print " 0,\n";
}
}
print " 0};\n\n";
print "U_NAMESPACE_END\n";
print "#endif\n";