#! /usr/bin/perl -w
# -*- Perl -*-
#
# afblue.pl
#
# Process a blue zone character data file.
#
# Copyright (C) 2013-2021 by
# David Turner, Robert Wilhelm, and Werner Lemberg.
#
# This file is part of the FreeType project, and may only be used,
# modified, and distributed under the terms of the FreeType project
# license, LICENSE.TXT. By continuing to use, modify, or distribute
# this file you indicate that you have read the license and
# understand and accept it fully.
use strict;
use warnings;
use English '-no_match_vars';
use open ':std', ':encoding(UTF-8)';
my $prog = $PROGRAM_NAME;
$prog =~ s| .* / ||x; # Remove path.
die "usage: $prog datafile < infile > outfile\n" if $#ARGV != 0;
my $datafile = $ARGV[0];
my %diversions; # The extracted and massaged data from `datafile'.
my @else_stack; # Booleans to track else-clauses.
my @name_stack; # Stack of integers used for names of aux. variables.
my $curr_enum; # Name of the current enumeration.
my $curr_array; # Name of the current array.
my $curr_max; # Name of the current maximum value.
my $curr_enum_element; # Name of the current enumeration element.
my $curr_offset; # The offset relative to current aux. variable.
my $curr_elem_size; # The number of non-space characters in the current string or
# the number of elements in the current block.
my $have_sections = 0; # Boolean; set if start of a section has been seen.
my $have_strings; # Boolean; set if current section contains strings.
my $have_blocks; # Boolean; set if current section contains blocks.
my $have_enum_element; # Boolean; set if we have an enumeration element.
my $in_string; # Boolean; set if a string has been parsed.
my $num_sections = 0; # Number of sections seen so far.
my $last_aux; # Name of last auxiliary variable.
# Regular expressions.
# [<ws>] <enum_name> <ws> <array_name> <ws> <max_name> [<ws>] ':' [<ws>] '\n'
my $section_re = qr/ ^ \s* (\S+) \s+ (\S+) \s+ (\S+) \s* : \s* $ /x;
# [<ws>] <enum_element_name> [<ws>] '\n'
my $enum_element_re = qr/ ^ \s* ( [A-Za-z0-9_]+ ) \s* $ /x;
# '#' <preprocessor directive> '\n'
my $preprocessor_re = qr/ ^ \# /x;
# [<ws>] '/' '/' <comment> '\n'
my $comment_re = qr| ^ \s* // |x;
# empty line
my $whitespace_only_re = qr/ ^ \s* $ /x;
# [<ws>] '"' <string> '"' [<ws>] '\n' (<string> doesn't contain newlines)
my $string_re = qr/ ^ \s*
" ( (?> (?: (?> [^"\\]+ ) | \\. )* ) ) "
\s* $ /x;
# [<ws>] '{' <block> '}' [<ws>] '\n' (<block> can contain newlines)
my $block_start_re = qr/ ^ \s* \{ /x;
# We need the capturing group for `split' to make it return the separator
# tokens (i.e., the opening and closing brace) also.
my $brace_re = qr/ ( [{}] ) /x;
sub Warn
{
my $message = shift;
warn "$datafile:$INPUT_LINE_NUMBER: warning: $message\n";
}
sub Die
{
my $message = shift;
die "$datafile:$INPUT_LINE_NUMBER: error: $message\n";
}
my $warned_before = 0;
sub warn_before
{
Warn("data before first section gets ignored") unless $warned_before;
$warned_before = 1;
}
sub strip_newline
{
chomp;
s/ \x0D $ //x;
}
sub end_curr_string
{
# Append final null byte to string.
if ($have_strings)
{
push @{$diversions{$curr_array}}, " '\\0',\n" if $in_string;
$curr_offset++;
$in_string = 0;
}
}
sub update_max_elem_size
{
if ($curr_elem_size)
{
my $max = pop @{$diversions{$curr_max}};
$max = $curr_elem_size if $curr_elem_size > $max;
push @{$diversions{$curr_max}}, $max;
}
}
sub convert_non_ascii_char
{
# A UTF-8 character outside of the printable ASCII range, with possibly a
# leading backslash character.
my $s = shift;
# Here we count characters, not bytes.
$curr_elem_size += length $s;
utf8::encode($s);
$s = uc unpack 'H*', $s;
$curr_offset += $s =~ s/\G(..)/'\\x$1', /sg;
return $s;
}
sub convert_ascii_chars
{
# A series of ASCII characters in the printable range.
my $s = shift;
# We reduce multiple space characters to a single one.
$s =~ s/ +/ /g;
# Count all non-space characters. Note that `()' applies a list context
# to the capture that is used to count the elements.
$curr_elem_size += () = $s =~ /[^ ]/g;
$curr_offset += $s =~ s/\G(.)/'$1', /g;
return $s;
}
sub convert_literal
{
my $s = shift;
my $orig = $s;
# ASCII printables and space
my $safe_re = '\x20-\x7E';
# ASCII printables and space, no backslash
my $safe_no_backslash_re = '\x20-\x5B\x5D-\x7E';
$s =~ s{
(?: \\? ( [^$safe_re] )
| ( (?: [$safe_no_backslash_re]
| \\ [$safe_re] )+ ) )
}
{
defined($1) ? convert_non_ascii_char($1)
: convert_ascii_chars($2)
}egx;
# We assume that `$orig' doesn't contain `*/'
return $s . " /* $orig */";
}
sub aux_name
{
return "af_blue_" . $num_sections. "_" . join('_', @name_stack);
}
sub aux_name_next
{
$name_stack[$#name_stack]++;
my $name = aux_name();
$name_stack[$#name_stack]--;
return $name;
}
sub enum_val_string
{
# Build string that holds code to save the current offset in an
# enumeration element.
my $aux = shift;
my $add = ($last_aux eq "af_blue_" . $num_sections . "_0" )
? ""
: "$last_aux + ";
return " $aux = $add$curr_offset,\n";
}
# Process data file.
open(DATA, $datafile) || die "$prog: can't open \`$datafile': $OS_ERROR\n";
while (<DATA>)
{
strip_newline();
next if /$comment_re/;
next if /$whitespace_only_re/;
if (/$section_re/)
{
Warn("previous section is empty") if ($have_sections
&& !$have_strings
&& !$have_blocks);
end_curr_string();
update_max_elem_size();
# Save captured groups from `section_re'.
$curr_enum = $1;
$curr_array = $2;
$curr_max = $3;
$curr_enum_element = "";
$curr_offset = 0;
Warn("overwriting already defined enumeration \`$curr_enum'")
if exists($diversions{$curr_enum});
Warn("overwriting already defined array \`$curr_array'")
if exists($diversions{$curr_array});
Warn("overwriting already defined maximum value \`$curr_max'")
if exists($diversions{$curr_max});
$diversions{$curr_enum} = [];
$diversions{$curr_array} = [];
$diversions{$curr_max} = [];
push @{$diversions{$curr_max}}, 0;
@name_stack = ();
push @name_stack, 0;
$have_sections = 1;
$have_strings = 0;
$have_blocks = 0;
$have_enum_element = 0;
$in_string = 0;
$num_sections++;
$curr_elem_size = 0;
$last_aux = aux_name();
next;
}
if (/$preprocessor_re/)
{
if ($have_sections)
{
# Having preprocessor conditionals complicates the computation of
# correct offset values. We have to introduce auxiliary enumeration
# elements with the name `af_blue_<s>_<n1>_<n2>_...' that store
# offsets to be used in conditional clauses. `<s>' is the number of
# sections seen so far, `<n1>' is the number of `#if' and `#endif'
# conditionals seen so far in the topmost level, `<n2>' the number of
# `#if' and `#endif' conditionals seen so far one level deeper, etc.
# As a consequence, uneven values are used within a clause, and even
# values after a clause, since the C standard doesn't allow the
# redefinition of an enumeration value. For example, the name
# `af_blue_5_1_6' is used to construct enumeration values in the fifth
# section after the third (second-level) if-clause within the first
# (top-level) if-clause. After the first top-level clause has
# finished, `af_blue_5_2' is used. The current offset is then
# relative to the value stored in the current auxiliary element.
if (/ ^ \# \s* if /x)
{
push @else_stack, 0;
$name_stack[$#name_stack]++;
push @{$diversions{$curr_enum}}, enum_val_string(aux_name());
$last_aux = aux_name();
push @name_stack, 0;
$curr_offset = 0;
}
elsif (/ ^ \# \s* elif /x)
{
Die("unbalanced #elif") unless @else_stack;
pop @name_stack;
push @{$diversions{$curr_enum}}, enum_val_string(aux_name_next());
$last_aux = aux_name();
push @name_stack, 0;
$curr_offset = 0;
}
elsif (/ ^ \# \s* else /x)
{
my $prev_else = pop @else_stack;
Die("unbalanced #else") unless defined($prev_else);
Die("#else already seen") if $prev_else;
push @else_stack, 1;
pop @name_stack;
push @{$diversions{$curr_enum}}, enum_val_string(aux_name_next());
$last_aux = aux_name();
push @name_stack, 0;
$curr_offset = 0;
}
elsif (/ ^ (\# \s*) endif /x)
{
my $prev_else = pop @else_stack;
Die("unbalanced #endif") unless defined($prev_else);
pop @name_stack;
# If there is no else-clause for an if-clause, we add one. This is
# necessary to have correct offsets.
if (!$prev_else)
{
# Use amount of whitespace from `endif'.
push @{$diversions{$curr_enum}}, enum_val_string(aux_name_next())
. $1 . "else\n";
$last_aux = aux_name();
$curr_offset = 0;
}
$name_stack[$#name_stack]++;
push @{$diversions{$curr_enum}}, enum_val_string(aux_name());
$last_aux = aux_name();
$curr_offset = 0;
}
# Handle (probably continued) preprocessor lines.
CONTINUED_LOOP:
{
do
{
strip_newline();
push @{$diversions{$curr_enum}}, $ARG . "\n";
push @{$diversions{$curr_array}}, $ARG . "\n";
last CONTINUED_LOOP unless / \\ $ /x;
} while (<DATA>);
}
}
else
{
warn_before();
}
next;
}
if (/$enum_element_re/)
{
end_curr_string();
update_max_elem_size();
$curr_enum_element = $1;
$have_enum_element = 1;
$curr_elem_size = 0;
next;
}
if (/$string_re/)
{
if ($have_sections)
{
Die("strings and blocks can't be mixed in a section") if $have_blocks;
# Save captured group from `string_re'.
my $string = $1;
if ($have_enum_element)
{
push @{$diversions{$curr_enum}}, enum_val_string($curr_enum_element);
$have_enum_element = 0;
}
$string = convert_literal($string);
push @{$diversions{$curr_array}}, " $string\n";
$have_strings = 1;
$in_string = 1;
}
else
{
warn_before();
}
next;
}
if (/$block_start_re/)
{
if ($have_sections)
{
Die("strings and blocks can't be mixed in a section") if $have_strings;
my $depth = 0;
my $block = "";
my $block_end = 0;
# Count braces while getting the block.
BRACE_LOOP:
{
do
{
strip_newline();
foreach my $substring (split(/$brace_re/))
{
if ($block_end)
{
Die("invalid data after last matching closing brace")
if $substring !~ /$whitespace_only_re/;
}
$block .= $substring;
if ($substring eq '{')
{
$depth++;
}
elsif ($substring eq '}')
{
$depth--;
$block_end = 1 if $depth == 0;
}
}
# If we are here, we have run out of substrings, so get next line
# or exit.
last BRACE_LOOP if $block_end;
$block .= "\n";
} while (<DATA>);
}
if ($have_enum_element)
{
push @{$diversions{$curr_enum}}, enum_val_string($curr_enum_element);
$have_enum_element = 0;
}
push @{$diversions{$curr_array}}, $block . ",\n";
$curr_offset++;
$curr_elem_size++;
$have_blocks = 1;
}
else
{
warn_before();
}
next;
}
# Garbage. We weren't able to parse the data.
Die("syntax error");
}
# Finalize data.
end_curr_string();
update_max_elem_size();
# Filter stdin to stdout, replacing `@...@' templates.
sub emit_diversion
{
my $diversion_name = shift;
return (exists($diversions{$1})) ? "@{$diversions{$1}}"
: "@" . $diversion_name . "@";
}
$LIST_SEPARATOR = '';
my $s1 = "This file has been generated by the Perl script \`$prog',";
my $s1len = length $s1;
my $s2 = "using data from file \`$datafile'.";
my $s2len = length $s2;
my $slen = ($s1len > $s2len) ? $s1len : $s2len;
print "/* " . $s1 . " " x ($slen - $s1len) . " */\n"
. "/* " . $s2 . " " x ($slen - $s2len) . " */\n"
. "\n";
while (<STDIN>)
{
s/ @ ( [A-Za-z0-9_]+? ) @ / emit_diversion($1) /egx;
print;
}
# EOF
