src/tools/afblue.pl - third_party/freetype2 - Git at Google

 #! /usr/bin/perl -w
 # -*- Perl -*-
 #
 # afblue.pl
 #
 # Process a blue zone character data file.
 #
 # Copyright (C) 2013-2022 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
	#! /usr/bin/perl -w
	# -- Perl --
	#
	# afblue.pl
	#
	# Process a blue zone character data file.
	#
	# Copyright (C) 2013-2022 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