1 | package ExtUtils::Constant::Base;
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2 |
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3 | use strict;
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4 | use vars qw($VERSION $is_perl56);
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5 | use Carp;
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6 | use Text::Wrap;
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7 | use ExtUtils::Constant::Utils qw(C_stringify perl_stringify);
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8 |
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9 | $VERSION = '0.01';
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10 |
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11 | $is_perl56 = ($] < 5.007 && $] > 5.005_50);
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12 |
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13 |
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14 | =head1 NAME
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15 |
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16 | ExtUtils::Constant::Base - base class for ExtUtils::Constant objects
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17 |
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18 | =head1 SYNOPSIS
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19 |
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20 | require ExtUtils::Constant::Base;
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21 | @ISA = 'ExtUtils::Constant::Base';
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22 |
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23 | =head1 DESCRIPTION
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24 |
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25 | ExtUtils::Constant::Base provides a base implementation of methods to
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26 | generate C code to give fast constant value lookup by named string. Currently
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27 | it's mostly used ExtUtils::Constant::XS, which generates the lookup code
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28 | for the constant() subroutine found in many XS modules.
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29 |
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30 | =head1 USAGE
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31 |
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32 | ExtUtils::Constant::Base exports no subroutines. The following methods are
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33 | available
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34 |
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35 | =over 4
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36 |
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37 | =cut
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38 |
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39 | sub valid_type {
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40 | # Default to assuming that you don't need different types of return data.
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41 | 1;
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42 | }
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43 | sub default_type {
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44 | '';
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45 | }
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46 |
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47 | =item header
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48 |
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49 | A method returning a scalar containing definitions needed, typically for a
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50 | C header file.
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51 |
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52 | =cut
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53 |
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54 | sub header {
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55 | ''
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56 | }
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57 |
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58 | # This might actually be a return statement. Note that you are responsible
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59 | # for any space you might need before your value, as it lets to perform
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60 | # "tricks" such as "return KEY_" and have strings appended.
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61 | sub assignment_clause_for_type;
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62 | # In which case this might be an empty string
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63 | sub return_statement_for_type {undef};
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64 | sub return_statement_for_notdef;
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65 | sub return_statement_for_notfound;
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66 |
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67 | # "#if 1" is true to a C pre-processor
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68 | sub macro_from_name {
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69 | 1;
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70 | }
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71 |
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72 | sub name_param {
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73 | 'name';
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74 | }
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75 |
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76 | # This is possibly buggy, in that it's not mandatory (below, in the main
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77 | # C_constant parameters, but is expected to exist here, if it's needed)
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78 | # Buggy because if you're definitely pure 8 bit only, and will never be
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79 | # presented with your constants in utf8, the default form of C_constant can't
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80 | # be told not to do the utf8 version.
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81 |
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82 | sub is_utf8_param {
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83 | 'utf8';
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84 | }
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85 |
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86 | sub memEQ {
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87 | "!memcmp";
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88 | }
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89 |
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90 | =item memEQ_clause args_hashref
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91 |
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92 | A method to return a suitable C C<if> statement to check whether I<name>
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93 | is equal to the C variable C<name>. If I<checked_at> is defined, then it
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94 | is used to avoid C<memEQ> for short names, or to generate a comment to
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95 | highlight the position of the character in the C<switch> statement.
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96 |
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97 | If i<checked_at> is a reference to a scalar, then instead it gives
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98 | the characters pre-checked at the beginning, (and the number of chars by
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99 | which the C variable name has been advanced. These need to be chopped from
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100 | the front of I<name>).
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101 |
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102 | =cut
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103 |
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104 | sub memEQ_clause {
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105 | # if (memEQ(name, "thingy", 6)) {
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106 | # Which could actually be a character comparison or even ""
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107 | my ($self, $args) = @_;
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108 | my ($name, $checked_at, $indent) = @{$args}{qw(name checked_at indent)};
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109 | $indent = ' ' x ($indent || 4);
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110 | my $front_chop;
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111 | if (ref $checked_at) {
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112 | # regexp won't work on 5.6.1 without use utf8; in turn that won't work
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113 | # on 5.005_03.
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114 | substr ($name, 0, length $$checked_at,) = '';
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115 | $front_chop = C_stringify ($$checked_at);
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116 | undef $checked_at;
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117 | }
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118 | my $len = length $name;
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119 |
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120 | if ($len < 2) {
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121 | return $indent . "{\n"
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122 | if (defined $checked_at and $checked_at == 0) or $len == 0;
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123 | # We didn't switch, drop through to the code for the 2 character string
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124 | $checked_at = 1;
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125 | }
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126 |
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127 | my $name_param = $self->name_param;
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128 |
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129 | if ($len < 3 and defined $checked_at) {
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130 | my $check;
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131 | if ($checked_at == 1) {
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132 | $check = 0;
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133 | } elsif ($checked_at == 0) {
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134 | $check = 1;
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135 | }
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136 | if (defined $check) {
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137 | my $char = C_stringify (substr $name, $check, 1);
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138 | # Placate 5.005 with a break in the string. I can't see a good way of
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139 | # getting it to not take [ as introducing an array lookup, even with
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140 | # ${name_param}[$check]
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141 | return $indent . "if ($name_param" . "[$check] == '$char') {\n";
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142 | }
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143 | }
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144 | if (($len == 2 and !defined $checked_at)
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145 | or ($len == 3 and defined ($checked_at) and $checked_at == 2)) {
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146 | my $char1 = C_stringify (substr $name, 0, 1);
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147 | my $char2 = C_stringify (substr $name, 1, 1);
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148 | return $indent .
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149 | "if ($name_param" . "[0] == '$char1' && $name_param" . "[1] == '$char2') {\n";
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150 | }
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151 | if (($len == 3 and defined ($checked_at) and $checked_at == 1)) {
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152 | my $char1 = C_stringify (substr $name, 0, 1);
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153 | my $char2 = C_stringify (substr $name, 2, 1);
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154 | return $indent .
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155 | "if ($name_param" . "[0] == '$char1' && $name_param" . "[2] == '$char2') {\n";
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156 | }
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157 |
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158 | my $pointer = '^';
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159 | my $have_checked_last = defined ($checked_at) && $len == $checked_at + 1;
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160 | if ($have_checked_last) {
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161 | # Checked at the last character, so no need to memEQ it.
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162 | $pointer = C_stringify (chop $name);
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163 | $len--;
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164 | }
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165 |
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166 | $name = C_stringify ($name);
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167 | my $memEQ = $self->memEQ();
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168 | my $body = $indent . "if ($memEQ($name_param, \"$name\", $len)) {\n";
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169 | # Put a little ^ under the letter we checked at
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170 | # Screws up for non printable and non-7 bit stuff, but that's too hard to
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171 | # get right.
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172 | if (defined $checked_at) {
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173 | $body .= $indent . "/* " . (' ' x length $memEQ)
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174 | . (' ' x length $name_param)
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175 | . (' ' x $checked_at) . $pointer
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176 | . (' ' x ($len - $checked_at + length $len)) . " */\n";
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177 | } elsif (defined $front_chop) {
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178 | $body .= $indent . "/* $front_chop"
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179 | . (' ' x ($len + 1 + length $len)) . " */\n";
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180 | }
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181 | return $body;
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182 | }
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183 |
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184 | =item dump_names arg_hashref, ITEM...
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185 |
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186 | An internal function to generate the embedded perl code that will regenerate
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187 | the constant subroutines. I<default_type>, I<types> and I<ITEM>s are the
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188 | same as for C_constant. I<indent> is treated as number of spaces to indent
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189 | by. If C<declare_types> is true a C<$types> is always declared in the perl
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190 | code generated, if defined and false never declared, and if undefined C<$types>
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191 | is only declared if the values in I<types> as passed in cannot be inferred from
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192 | I<default_types> and the I<ITEM>s.
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193 |
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194 | =cut
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195 |
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196 | sub dump_names {
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197 | my ($self, $args, @items) = @_;
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198 | my ($default_type, $what, $indent, $declare_types)
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199 | = @{$args}{qw(default_type what indent declare_types)};
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200 | $indent = ' ' x ($indent || 0);
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201 |
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202 | my $result;
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203 | my (@simple, @complex, %used_types);
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204 | foreach (@items) {
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205 | my $type;
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206 | if (ref $_) {
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207 | $type = $_->{type} || $default_type;
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208 | if ($_->{utf8}) {
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209 | # For simplicity always skip the bytes case, and reconstitute this entry
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210 | # from its utf8 twin.
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211 | next if $_->{utf8} eq 'no';
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212 | # Copy the hashref, as we don't want to mess with the caller's hashref.
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213 | $_ = {%$_};
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214 | unless ($is_perl56) {
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215 | utf8::decode ($_->{name});
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216 | } else {
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217 | $_->{name} = pack 'U*', unpack 'U0U*', $_->{name};
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218 | }
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219 | delete $_->{utf8};
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220 | }
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221 | } else {
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222 | $_ = {name=>$_};
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223 | $type = $default_type;
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224 | }
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225 | $used_types{$type}++;
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226 | if ($type eq $default_type
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227 | # grr 5.6.1
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228 | and length $_->{name}
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229 | and length $_->{name} == ($_->{name} =~ tr/A-Za-z0-9_//)
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230 | and !defined ($_->{macro}) and !defined ($_->{value})
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231 | and !defined ($_->{default}) and !defined ($_->{pre})
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232 | and !defined ($_->{post}) and !defined ($_->{def_pre})
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233 | and !defined ($_->{def_post}) and !defined ($_->{weight})) {
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234 | # It's the default type, and the name consists only of A-Za-z0-9_
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235 | push @simple, $_->{name};
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236 | } else {
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237 | push @complex, $_;
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238 | }
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239 | }
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240 |
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241 | if (!defined $declare_types) {
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242 | # Do they pass in any types we weren't already using?
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243 | foreach (keys %$what) {
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244 | next if $used_types{$_};
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245 | $declare_types++; # Found one in $what that wasn't used.
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246 | last; # And one is enough to terminate this loop
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247 | }
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248 | }
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249 | if ($declare_types) {
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250 | $result = $indent . 'my $types = {map {($_, 1)} qw('
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251 | . join (" ", sort keys %$what) . ")};\n";
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252 | }
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253 | local $Text::Wrap::huge = 'overflow';
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254 | local $Text::Wrap::columns = 80;
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255 | $result .= wrap ($indent . "my \@names = (qw(",
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256 | $indent . " ", join (" ", sort @simple) . ")");
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257 | if (@complex) {
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258 | foreach my $item (sort {$a->{name} cmp $b->{name}} @complex) {
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259 | my $name = perl_stringify $item->{name};
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260 | my $line = ",\n$indent {name=>\"$name\"";
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261 | $line .= ", type=>\"$item->{type}\"" if defined $item->{type};
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262 | foreach my $thing (qw (macro value default pre post def_pre def_post)) {
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263 | my $value = $item->{$thing};
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264 | if (defined $value) {
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265 | if (ref $value) {
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266 | $line .= ", $thing=>[\""
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267 | . join ('", "', map {perl_stringify $_} @$value) . '"]';
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268 | } else {
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269 | $line .= ", $thing=>\"" . perl_stringify($value) . "\"";
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270 | }
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271 | }
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272 | }
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273 | $line .= "}";
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274 | # Ensure that the enclosing C comment doesn't end
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275 | # by turning */ into *" . "/
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276 | $line =~ s!\*\/!\*" . "/!gs;
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277 | # gcc -Wall doesn't like finding /* inside a comment
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278 | $line =~ s!\/\*!/" . "\*!gs;
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279 | $result .= $line;
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280 | }
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281 | }
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282 | $result .= ");\n";
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283 |
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284 | $result;
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285 | }
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286 |
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287 | =item assign arg_hashref, VALUE...
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288 |
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289 | A method to return a suitable assignment clause. If I<type> is aggregate
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290 | (eg I<PVN> expects both pointer and length) then there should be multiple
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291 | I<VALUE>s for the components. I<pre> and I<post> if defined give snippets
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292 | of C code to proceed and follow the assignment. I<pre> will be at the start
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293 | of a block, so variables may be defined in it.
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294 |
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295 | =cut
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296 | # Hmm. value undef to to NOTDEF? value () to do NOTFOUND?
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297 |
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298 | sub assign {
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299 | my $self = shift;
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300 | my $args = shift;
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301 | my ($indent, $type, $pre, $post, $item)
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302 | = @{$args}{qw(indent type pre post item)};
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303 | $post ||= '';
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304 | my $clause;
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305 | my $close;
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306 | if ($pre) {
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307 | chomp $pre;
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308 | $close = "$indent}\n";
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309 | $clause = $indent . "{\n";
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310 | $indent .= " ";
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311 | $clause .= "$indent$pre";
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312 | $clause .= ";" unless $pre =~ /;$/;
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313 | $clause .= "\n";
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314 | }
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315 | confess "undef \$type" unless defined $type;
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316 | confess "Can't generate code for type $type"
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317 | unless $self->valid_type($type);
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318 |
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319 | $clause .= join '', map {"$indent$_\n"}
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320 | $self->assignment_clause_for_type({type=>$type,item=>$item}, @_);
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321 | chomp $post;
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322 | if (length $post) {
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323 | $clause .= "$post";
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324 | $clause .= ";" unless $post =~ /;$/;
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325 | $clause .= "\n";
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326 | }
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327 | my $return = $self->return_statement_for_type($type);
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328 | $clause .= "$indent$return\n" if defined $return;
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329 | $clause .= $close if $close;
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330 | return $clause;
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331 | }
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332 |
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333 | =item return_clause arg_hashref, ITEM
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334 |
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335 | A method to return a suitable C<#ifdef> clause. I<ITEM> is a hashref
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336 | (as passed to C<C_constant> and C<match_clause>. I<indent> is the number
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337 | of spaces to indent, defaulting to 6.
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338 |
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339 | =cut
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340 |
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341 | sub return_clause {
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342 |
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343 | ##ifdef thingy
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344 | # *iv_return = thingy;
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345 | # return PERL_constant_ISIV;
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346 | ##else
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347 | # return PERL_constant_NOTDEF;
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348 | ##endif
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349 | my ($self, $args, $item) = @_;
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350 | my $indent = $args->{indent};
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351 |
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352 | my ($name, $value, $macro, $default, $pre, $post, $def_pre, $def_post, $type)
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353 | = @$item{qw (name value macro default pre post def_pre def_post type)};
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354 | $value = $name unless defined $value;
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355 | $macro = $self->macro_from_name($item) unless defined $macro;
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356 | # "#if 1" is true to a C pre-processor
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357 | $macro = 1 if !defined $macro or $macro eq '';
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358 | $indent = ' ' x ($indent || 6);
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359 | unless (defined $type) {
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360 | # use Data::Dumper; print STDERR Dumper ($item);
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361 | confess "undef \$type";
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362 | }
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363 |
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364 | my $clause;
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365 |
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366 | ##ifdef thingy
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367 | if (ref $macro) {
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368 | $clause = $macro->[0];
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369 | } elsif ($macro ne "1") {
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370 | $clause = "#ifdef $macro\n";
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371 | }
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372 |
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373 | # *iv_return = thingy;
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374 | # return PERL_constant_ISIV;
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375 | $clause
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376 | .= $self->assign ({indent=>$indent, type=>$type, pre=>$pre, post=>$post,
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377 | item=>$item}, ref $value ? @$value : $value);
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378 |
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379 | if (ref $macro or $macro ne "1") {
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380 | ##else
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381 | $clause .= "#else\n";
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382 |
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383 | # return PERL_constant_NOTDEF;
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384 | if (!defined $default) {
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385 | my $notdef = $self->return_statement_for_notdef();
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386 | $clause .= "$indent$notdef\n" if defined $notdef;
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387 | } else {
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388 | my @default = ref $default ? @$default : $default;
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389 | $type = shift @default;
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390 | $clause .= $self->assign ({indent=>$indent, type=>$type, pre=>$pre,
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391 | post=>$post, item=>$item}, @default);
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392 | }
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393 |
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394 | ##endif
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395 | if (ref $macro) {
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396 | $clause .= $macro->[1];
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397 | } else {
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398 | $clause .= "#endif\n";
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399 | }
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400 | }
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401 | return $clause;
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402 | }
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403 |
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404 | sub match_clause {
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405 | # $offset defined if we have checked an offset.
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406 | my ($self, $args, $item) = @_;
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407 | my ($offset, $indent) = @{$args}{qw(checked_at indent)};
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408 | $indent = ' ' x ($indent || 4);
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409 | my $body = '';
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410 | my ($no, $yes, $either, $name, $inner_indent);
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411 | if (ref $item eq 'ARRAY') {
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412 | ($yes, $no) = @$item;
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413 | $either = $yes || $no;
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414 | confess "$item is $either expecting hashref in [0] || [1]"
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415 | unless ref $either eq 'HASH';
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416 | $name = $either->{name};
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417 | } else {
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418 | confess "$item->{name} has utf8 flag '$item->{utf8}', should be false"
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419 | if $item->{utf8};
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420 | $name = $item->{name};
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421 | $inner_indent = $indent;
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422 | }
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423 |
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424 | $body .= $self->memEQ_clause ({name => $name, checked_at => $offset,
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425 | indent => length $indent});
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426 | # If we've been presented with an arrayref for $item, then the user string
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427 | # contains in the range 128-255, and we need to check whether it was utf8
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428 | # (or not).
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429 | # In the worst case we have two named constants, where one's name happens
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430 | # encoded in UTF8 happens to be the same byte sequence as the second's
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431 | # encoded in (say) ISO-8859-1.
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432 | # In this case, $yes and $no both have item hashrefs.
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433 | if ($yes) {
|
---|
434 | $body .= $indent . " if (" . $self->is_utf8_param . ") {\n";
|
---|
435 | } elsif ($no) {
|
---|
436 | $body .= $indent . " if (!" . $self->is_utf8_param . ") {\n";
|
---|
437 | }
|
---|
438 | if ($either) {
|
---|
439 | $body .= $self->return_clause ({indent=>4 + length $indent}, $either);
|
---|
440 | if ($yes and $no) {
|
---|
441 | $body .= $indent . " } else {\n";
|
---|
442 | $body .= $self->return_clause ({indent=>4 + length $indent}, $no);
|
---|
443 | }
|
---|
444 | $body .= $indent . " }\n";
|
---|
445 | } else {
|
---|
446 | $body .= $self->return_clause ({indent=>2 + length $indent}, $item);
|
---|
447 | }
|
---|
448 | $body .= $indent . "}\n";
|
---|
449 | }
|
---|
450 |
|
---|
451 |
|
---|
452 | =item switch_clause arg_hashref, NAMELEN, ITEMHASH, ITEM...
|
---|
453 |
|
---|
454 | An internal method to generate a suitable C<switch> clause, called by
|
---|
455 | C<C_constant> I<ITEM>s are in the hash ref format as given in the description
|
---|
456 | of C<C_constant>, and must all have the names of the same length, given by
|
---|
457 | I<NAMELEN>. I<ITEMHASH> is a reference to a hash, keyed by name, values being
|
---|
458 | the hashrefs in the I<ITEM> list. (No parameters are modified, and there can
|
---|
459 | be keys in the I<ITEMHASH> that are not in the list of I<ITEM>s without
|
---|
460 | causing problems - the hash is passed in to save generating it afresh for
|
---|
461 | each call).
|
---|
462 |
|
---|
463 | =cut
|
---|
464 |
|
---|
465 | sub switch_clause {
|
---|
466 | my ($self, $args, $namelen, $items, @items) = @_;
|
---|
467 | my ($indent, $comment) = @{$args}{qw(indent comment)};
|
---|
468 | $indent = ' ' x ($indent || 2);
|
---|
469 |
|
---|
470 | local $Text::Wrap::huge = 'overflow';
|
---|
471 | local $Text::Wrap::columns = 80;
|
---|
472 |
|
---|
473 | my @names = sort map {$_->{name}} @items;
|
---|
474 | my $leader = $indent . '/* ';
|
---|
475 | my $follower = ' ' x length $leader;
|
---|
476 | my $body = $indent . "/* Names all of length $namelen. */\n";
|
---|
477 | if (defined $comment) {
|
---|
478 | $body = wrap ($leader, $follower, $comment) . "\n";
|
---|
479 | $leader = $follower;
|
---|
480 | }
|
---|
481 | my @safe_names = @names;
|
---|
482 | foreach (@safe_names) {
|
---|
483 | confess sprintf "Name '$_' is length %d, not $namelen", length
|
---|
484 | unless length == $namelen;
|
---|
485 | # Argh. 5.6.1
|
---|
486 | # next unless tr/A-Za-z0-9_//c;
|
---|
487 | next if tr/A-Za-z0-9_// == length;
|
---|
488 | $_ = '"' . perl_stringify ($_) . '"';
|
---|
489 | # Ensure that the enclosing C comment doesn't end
|
---|
490 | # by turning */ into *" . "/
|
---|
491 | s!\*\/!\*"."/!gs;
|
---|
492 | # gcc -Wall doesn't like finding /* inside a comment
|
---|
493 | s!\/\*!/"."\*!gs;
|
---|
494 | }
|
---|
495 | $body .= wrap ($leader, $follower, join (" ", @safe_names) . " */") . "\n";
|
---|
496 | # Figure out what to switch on.
|
---|
497 | # (RMS, Spread of jump table, Position, Hashref)
|
---|
498 | my @best = (1e38, ~0);
|
---|
499 | # Prefer the last character over the others. (As it lets us shorten the
|
---|
500 | # memEQ clause at no cost).
|
---|
501 | foreach my $i ($namelen - 1, 0 .. ($namelen - 2)) {
|
---|
502 | my ($min, $max) = (~0, 0);
|
---|
503 | my %spread;
|
---|
504 | if ($is_perl56) {
|
---|
505 | # Need proper Unicode preserving hash keys for bytes in range 128-255
|
---|
506 | # here too, for some reason. grr 5.6.1 yet again.
|
---|
507 | tie %spread, 'ExtUtils::Constant::Aaargh56Hash';
|
---|
508 | }
|
---|
509 | foreach (@names) {
|
---|
510 | my $char = substr $_, $i, 1;
|
---|
511 | my $ord = ord $char;
|
---|
512 | confess "char $ord is out of range" if $ord > 255;
|
---|
513 | $max = $ord if $ord > $max;
|
---|
514 | $min = $ord if $ord < $min;
|
---|
515 | push @{$spread{$char}}, $_;
|
---|
516 | # warn "$_ $char";
|
---|
517 | }
|
---|
518 | # I'm going to pick the character to split on that minimises the root
|
---|
519 | # mean square of the number of names in each case. Normally this should
|
---|
520 | # be the one with the most keys, but it may pick a 7 where the 8 has
|
---|
521 | # one long linear search. I'm not sure if RMS or just sum of squares is
|
---|
522 | # actually better.
|
---|
523 | # $max and $min are for the tie-breaker if the root mean squares match.
|
---|
524 | # Assuming that the compiler may be building a jump table for the
|
---|
525 | # switch() then try to minimise the size of that jump table.
|
---|
526 | # Finally use < not <= so that if it still ties the earliest part of
|
---|
527 | # the string wins. Because if that passes but the memEQ fails, it may
|
---|
528 | # only need the start of the string to bin the choice.
|
---|
529 | # I think. But I'm micro-optimising. :-)
|
---|
530 | # OK. Trump that. Now favour the last character of the string, before the
|
---|
531 | # rest.
|
---|
532 | my $ss;
|
---|
533 | $ss += @$_ * @$_ foreach values %spread;
|
---|
534 | my $rms = sqrt ($ss / keys %spread);
|
---|
535 | if ($rms < $best[0] || ($rms == $best[0] && ($max - $min) < $best[1])) {
|
---|
536 | @best = ($rms, $max - $min, $i, \%spread);
|
---|
537 | }
|
---|
538 | }
|
---|
539 | confess "Internal error. Failed to pick a switch point for @names"
|
---|
540 | unless defined $best[2];
|
---|
541 | # use Data::Dumper; print Dumper (@best);
|
---|
542 | my ($offset, $best) = @best[2,3];
|
---|
543 | $body .= $indent . "/* Offset $offset gives the best switch position. */\n";
|
---|
544 |
|
---|
545 | my $do_front_chop = $offset == 0 && $namelen > 2;
|
---|
546 | if ($do_front_chop) {
|
---|
547 | $body .= $indent . "switch (*" . $self->name_param() . "++) {\n";
|
---|
548 | } else {
|
---|
549 | $body .= $indent . "switch (" . $self->name_param() . "[$offset]) {\n";
|
---|
550 | }
|
---|
551 | foreach my $char (sort keys %$best) {
|
---|
552 | confess sprintf "'$char' is %d bytes long, not 1", length $char
|
---|
553 | if length ($char) != 1;
|
---|
554 | confess sprintf "char %#X is out of range", ord $char if ord ($char) > 255;
|
---|
555 | $body .= $indent . "case '" . C_stringify ($char) . "':\n";
|
---|
556 | foreach my $thisone (sort {
|
---|
557 | # Deal with the case of an item actually being an array ref to 1 or 2
|
---|
558 | # hashrefs. Don't assign to $a or $b, as they're aliases to the orignal
|
---|
559 | my $l = ref $a eq 'ARRAY' ? ($a->[0] || $->[1]) : $a;
|
---|
560 | my $r = ref $b eq 'ARRAY' ? ($b->[0] || $->[1]) : $b;
|
---|
561 | # Sort by weight first
|
---|
562 | ($r->{weight} || 0) <=> ($l->{weight} || 0)
|
---|
563 | # Sort equal weights by name
|
---|
564 | or $l->{name} cmp $r->{name}}
|
---|
565 | # If this looks evil, maybe it is. $items is a
|
---|
566 | # hashref, and we're doing a hash slice on it
|
---|
567 | @{$items}{@{$best->{$char}}}) {
|
---|
568 | # warn "You are here";
|
---|
569 | if ($do_front_chop) {
|
---|
570 | $body .= $self->match_clause ({indent => 2 + length $indent,
|
---|
571 | checked_at => \$char}, $thisone);
|
---|
572 | } else {
|
---|
573 | $body .= $self->match_clause ({indent => 2 + length $indent,
|
---|
574 | checked_at => $offset}, $thisone);
|
---|
575 | }
|
---|
576 | }
|
---|
577 | $body .= $indent . " break;\n";
|
---|
578 | }
|
---|
579 | $body .= $indent . "}\n";
|
---|
580 | return $body;
|
---|
581 | }
|
---|
582 |
|
---|
583 | sub C_constant_return_type {
|
---|
584 | "static int";
|
---|
585 | }
|
---|
586 |
|
---|
587 | sub C_constant_prefix_param {
|
---|
588 | '';
|
---|
589 | }
|
---|
590 |
|
---|
591 | sub C_constant_prefix_param_defintion {
|
---|
592 | '';
|
---|
593 | }
|
---|
594 |
|
---|
595 | sub name_param_definition {
|
---|
596 | "const char *" . $_[0]->name_param;
|
---|
597 | }
|
---|
598 |
|
---|
599 | sub namelen_param {
|
---|
600 | 'len';
|
---|
601 | }
|
---|
602 |
|
---|
603 | sub namelen_param_definition {
|
---|
604 | 'size_t ' . $_[0]->namelen_param;
|
---|
605 | }
|
---|
606 |
|
---|
607 | sub C_constant_other_params {
|
---|
608 | '';
|
---|
609 | }
|
---|
610 |
|
---|
611 | sub C_constant_other_params_defintion {
|
---|
612 | '';
|
---|
613 | }
|
---|
614 |
|
---|
615 | =item params WHAT
|
---|
616 |
|
---|
617 | An "internal" method, subject to change, currently called to allow an
|
---|
618 | overriding class to cache information that will then be passed into all
|
---|
619 | the C<*param*> calls. (Yes, having to read the source to make sense of this is
|
---|
620 | considered a known bug). I<WHAT> is be a hashref of types the constant
|
---|
621 | function will return. In ExtUtils::Constant::XS this method is used to
|
---|
622 | returns a hashref keyed IV NV PV SV to show which combination of pointers will
|
---|
623 | be needed in the C argument list generated by
|
---|
624 | C_constant_other_params_definition and C_constant_other_params
|
---|
625 |
|
---|
626 | =cut
|
---|
627 |
|
---|
628 | sub params {
|
---|
629 | '';
|
---|
630 | }
|
---|
631 |
|
---|
632 |
|
---|
633 | =item dogfood arg_hashref, ITEM...
|
---|
634 |
|
---|
635 | An internal function to generate the embedded perl code that will regenerate
|
---|
636 | the constant subroutines. Parameters are the same as for C_constant.
|
---|
637 |
|
---|
638 | Currently the base class does nothing and returns an empty string.
|
---|
639 |
|
---|
640 | =cut
|
---|
641 |
|
---|
642 | sub dogfood {
|
---|
643 | ''
|
---|
644 | }
|
---|
645 |
|
---|
646 | =item C_constant arg_hashref, ITEM...
|
---|
647 |
|
---|
648 | A function that returns a B<list> of C subroutine definitions that return
|
---|
649 | the value and type of constants when passed the name by the XS wrapper.
|
---|
650 | I<ITEM...> gives a list of constant names. Each can either be a string,
|
---|
651 | which is taken as a C macro name, or a reference to a hash with the following
|
---|
652 | keys
|
---|
653 |
|
---|
654 | =over 8
|
---|
655 |
|
---|
656 | =item name
|
---|
657 |
|
---|
658 | The name of the constant, as seen by the perl code.
|
---|
659 |
|
---|
660 | =item type
|
---|
661 |
|
---|
662 | The type of the constant (I<IV>, I<NV> etc)
|
---|
663 |
|
---|
664 | =item value
|
---|
665 |
|
---|
666 | A C expression for the value of the constant, or a list of C expressions if
|
---|
667 | the type is aggregate. This defaults to the I<name> if not given.
|
---|
668 |
|
---|
669 | =item macro
|
---|
670 |
|
---|
671 | The C pre-processor macro to use in the C<#ifdef>. This defaults to the
|
---|
672 | I<name>, and is mainly used if I<value> is an C<enum>. If a reference an
|
---|
673 | array is passed then the first element is used in place of the C<#ifdef>
|
---|
674 | line, and the second element in place of the C<#endif>. This allows
|
---|
675 | pre-processor constructions such as
|
---|
676 |
|
---|
677 | #if defined (foo)
|
---|
678 | #if !defined (bar)
|
---|
679 | ...
|
---|
680 | #endif
|
---|
681 | #endif
|
---|
682 |
|
---|
683 | to be used to determine if a constant is to be defined.
|
---|
684 |
|
---|
685 | A "macro" 1 signals that the constant is always defined, so the C<#if>/C<#endif>
|
---|
686 | test is omitted.
|
---|
687 |
|
---|
688 | =item default
|
---|
689 |
|
---|
690 | Default value to use (instead of C<croak>ing with "your vendor has not
|
---|
691 | defined...") to return if the macro isn't defined. Specify a reference to
|
---|
692 | an array with type followed by value(s).
|
---|
693 |
|
---|
694 | =item pre
|
---|
695 |
|
---|
696 | C code to use before the assignment of the value of the constant. This allows
|
---|
697 | you to use temporary variables to extract a value from part of a C<struct>
|
---|
698 | and return this as I<value>. This C code is places at the start of a block,
|
---|
699 | so you can declare variables in it.
|
---|
700 |
|
---|
701 | =item post
|
---|
702 |
|
---|
703 | C code to place between the assignment of value (to a temporary) and the
|
---|
704 | return from the function. This allows you to clear up anything in I<pre>.
|
---|
705 | Rarely needed.
|
---|
706 |
|
---|
707 | =item def_pre
|
---|
708 |
|
---|
709 | =item def_post
|
---|
710 |
|
---|
711 | Equivalents of I<pre> and I<post> for the default value.
|
---|
712 |
|
---|
713 | =item utf8
|
---|
714 |
|
---|
715 | Generated internally. Is zero or undefined if name is 7 bit ASCII,
|
---|
716 | "no" if the name is 8 bit (and so should only match if SvUTF8() is false),
|
---|
717 | "yes" if the name is utf8 encoded.
|
---|
718 |
|
---|
719 | The internals automatically clone any name with characters 128-255 but none
|
---|
720 | 256+ (ie one that could be either in bytes or utf8) into a second entry
|
---|
721 | which is utf8 encoded.
|
---|
722 |
|
---|
723 | =item weight
|
---|
724 |
|
---|
725 | Optional sorting weight for names, to determine the order of
|
---|
726 | linear testing when multiple names fall in the same case of a switch clause.
|
---|
727 | Higher comes earlier, undefined defaults to zero.
|
---|
728 |
|
---|
729 | =back
|
---|
730 |
|
---|
731 | In the argument hashref, I<package> is the name of the package, and is only
|
---|
732 | used in comments inside the generated C code. I<subname> defaults to
|
---|
733 | C<constant> if undefined.
|
---|
734 |
|
---|
735 | I<default_type> is the type returned by C<ITEM>s that don't specify their
|
---|
736 | type. It defaults to the value of C<default_type()>. I<types> should be given
|
---|
737 | either as a comma separated list of types that the C subroutine I<subname>
|
---|
738 | will generate or as a reference to a hash. I<default_type> will be added to
|
---|
739 | the list if not present, as will any types given in the list of I<ITEM>s. The
|
---|
740 | resultant list should be the same list of types that C<XS_constant> is
|
---|
741 | given. [Otherwise C<XS_constant> and C<C_constant> may differ in the number of
|
---|
742 | parameters to the constant function. I<indent> is currently unused and
|
---|
743 | ignored. In future it may be used to pass in information used to change the C
|
---|
744 | indentation style used.] The best way to maintain consistency is to pass in a
|
---|
745 | hash reference and let this function update it.
|
---|
746 |
|
---|
747 | I<breakout> governs when child functions of I<subname> are generated. If there
|
---|
748 | are I<breakout> or more I<ITEM>s with the same length of name, then the code
|
---|
749 | to switch between them is placed into a function named I<subname>_I<len>, for
|
---|
750 | example C<constant_5> for names 5 characters long. The default I<breakout> is
|
---|
751 | 3. A single C<ITEM> is always inlined.
|
---|
752 |
|
---|
753 | =cut
|
---|
754 |
|
---|
755 | # The parameter now BREAKOUT was previously documented as:
|
---|
756 | #
|
---|
757 | # I<NAMELEN> if defined signals that all the I<name>s of the I<ITEM>s are of
|
---|
758 | # this length, and that the constant name passed in by perl is checked and
|
---|
759 | # also of this length. It is used during recursion, and should be C<undef>
|
---|
760 | # unless the caller has checked all the lengths during code generation, and
|
---|
761 | # the generated subroutine is only to be called with a name of this length.
|
---|
762 | #
|
---|
763 | # As you can see it now performs this function during recursion by being a
|
---|
764 | # scalar reference.
|
---|
765 |
|
---|
766 | sub C_constant {
|
---|
767 | my ($self, $args, @items) = @_;
|
---|
768 | my ($package, $subname, $default_type, $what, $indent, $breakout) =
|
---|
769 | @{$args}{qw(package subname default_type types indent breakout)};
|
---|
770 | $package ||= 'Foo';
|
---|
771 | $subname ||= 'constant';
|
---|
772 | # I'm not using this. But a hashref could be used for full formatting without
|
---|
773 | # breaking this API
|
---|
774 | # $indent ||= 0;
|
---|
775 |
|
---|
776 | my ($namelen, $items);
|
---|
777 | if (ref $breakout) {
|
---|
778 | # We are called recursively. We trust @items to be normalised, $what to
|
---|
779 | # be a hashref, and pinch %$items from our parent to save recalculation.
|
---|
780 | ($namelen, $items) = @$breakout;
|
---|
781 | } else {
|
---|
782 | if ($is_perl56) {
|
---|
783 | # Need proper Unicode preserving hash keys.
|
---|
784 | require ExtUtils::Constant::Aaargh56Hash;
|
---|
785 | $items = {};
|
---|
786 | tie %$items, 'ExtUtils::Constant::Aaargh56Hash';
|
---|
787 | }
|
---|
788 | $breakout ||= 3;
|
---|
789 | $default_type ||= $self->default_type();
|
---|
790 | if (!ref $what) {
|
---|
791 | # Convert line of the form IV,UV,NV to hash
|
---|
792 | $what = {map {$_ => 1} split /,\s*/, ($what || '')};
|
---|
793 | # Figure out what types we're dealing with, and assign all unknowns to the
|
---|
794 | # default type
|
---|
795 | }
|
---|
796 | my @new_items;
|
---|
797 | foreach my $orig (@items) {
|
---|
798 | my ($name, $item);
|
---|
799 | if (ref $orig) {
|
---|
800 | # Make a copy which is a normalised version of the ref passed in.
|
---|
801 | $name = $orig->{name};
|
---|
802 | my ($type, $macro, $value) = @$orig{qw (type macro value)};
|
---|
803 | $type ||= $default_type;
|
---|
804 | $what->{$type} = 1;
|
---|
805 | $item = {name=>$name, type=>$type};
|
---|
806 |
|
---|
807 | undef $macro if defined $macro and $macro eq $name;
|
---|
808 | $item->{macro} = $macro if defined $macro;
|
---|
809 | undef $value if defined $value and $value eq $name;
|
---|
810 | $item->{value} = $value if defined $value;
|
---|
811 | foreach my $key (qw(default pre post def_pre def_post weight)) {
|
---|
812 | my $value = $orig->{$key};
|
---|
813 | $item->{$key} = $value if defined $value;
|
---|
814 | # warn "$key $value";
|
---|
815 | }
|
---|
816 | } else {
|
---|
817 | $name = $orig;
|
---|
818 | $item = {name=>$name, type=>$default_type};
|
---|
819 | $what->{$default_type} = 1;
|
---|
820 | }
|
---|
821 | warn +(ref ($self) || $self)
|
---|
822 | . "doesn't know how to handle values of type $_ used in macro $name"
|
---|
823 | unless $self->valid_type ($item->{type});
|
---|
824 | # tr///c is broken on 5.6.1 for utf8, so my original tr/\0-\177//c
|
---|
825 | # doesn't work. Upgrade to 5.8
|
---|
826 | # if ($name !~ tr/\0-\177//c || $] < 5.005_50) {
|
---|
827 | if ($name =~ tr/\0-\177// == length $name || $] < 5.005_50) {
|
---|
828 | # No characters outside 7 bit ASCII.
|
---|
829 | if (exists $items->{$name}) {
|
---|
830 | die "Multiple definitions for macro $name";
|
---|
831 | }
|
---|
832 | $items->{$name} = $item;
|
---|
833 | } else {
|
---|
834 | # No characters outside 8 bit. This is hardest.
|
---|
835 | if (exists $items->{$name} and ref $items->{$name} ne 'ARRAY') {
|
---|
836 | confess "Unexpected ASCII definition for macro $name";
|
---|
837 | }
|
---|
838 | # Again, 5.6.1 tr broken, so s/5\.6.*/5\.8\.0/;
|
---|
839 | # if ($name !~ tr/\0-\377//c) {
|
---|
840 | if ($name =~ tr/\0-\377// == length $name) {
|
---|
841 | # if ($] < 5.007) {
|
---|
842 | # $name = pack "C*", unpack "U*", $name;
|
---|
843 | # }
|
---|
844 | $item->{utf8} = 'no';
|
---|
845 | $items->{$name}[1] = $item;
|
---|
846 | push @new_items, $item;
|
---|
847 | # Copy item, to create the utf8 variant.
|
---|
848 | $item = {%$item};
|
---|
849 | }
|
---|
850 | # Encode the name as utf8 bytes.
|
---|
851 | unless ($is_perl56) {
|
---|
852 | utf8::encode($name);
|
---|
853 | } else {
|
---|
854 | # warn "Was >$name< " . length ${name};
|
---|
855 | $name = pack 'C*', unpack 'C*', $name . pack 'U*';
|
---|
856 | # warn "Now '${name}' " . length ${name};
|
---|
857 | }
|
---|
858 | if ($items->{$name}[0]) {
|
---|
859 | die "Multiple definitions for macro $name";
|
---|
860 | }
|
---|
861 | $item->{utf8} = 'yes';
|
---|
862 | $item->{name} = $name;
|
---|
863 | $items->{$name}[0] = $item;
|
---|
864 | # We have need for the utf8 flag.
|
---|
865 | $what->{''} = 1;
|
---|
866 | }
|
---|
867 | push @new_items, $item;
|
---|
868 | }
|
---|
869 | @items = @new_items;
|
---|
870 | # use Data::Dumper; print Dumper @items;
|
---|
871 | }
|
---|
872 | my $params = $self->params ($what);
|
---|
873 |
|
---|
874 | # Probably "static int"
|
---|
875 | my ($body, @subs);
|
---|
876 | $body = $self->C_constant_return_type($params) . "\n$subname ("
|
---|
877 | # Eg "pTHX_ "
|
---|
878 | . $self->C_constant_prefix_param_defintion($params)
|
---|
879 | # Probably "const char *name"
|
---|
880 | . $self->name_param_definition($params);
|
---|
881 | # Something like ", STRLEN len"
|
---|
882 | $body .= ", " . $self->namelen_param_definition($params)
|
---|
883 | unless defined $namelen;
|
---|
884 | $body .= $self->C_constant_other_params_defintion($params);
|
---|
885 | $body .= ") {\n";
|
---|
886 |
|
---|
887 | if (defined $namelen) {
|
---|
888 | # We are a child subroutine. Print the simple description
|
---|
889 | my $comment = 'When generated this function returned values for the list'
|
---|
890 | . ' of names given here. However, subsequent manual editing may have'
|
---|
891 | . ' added or removed some.';
|
---|
892 | $body .= $self->switch_clause ({indent=>2, comment=>$comment},
|
---|
893 | $namelen, $items, @items);
|
---|
894 | } else {
|
---|
895 | # We are the top level.
|
---|
896 | $body .= " /* Initially switch on the length of the name. */\n";
|
---|
897 | $body .= $self->dogfood ({package => $package, subname => $subname,
|
---|
898 | default_type => $default_type, what => $what,
|
---|
899 | indent => $indent, breakout => $breakout},
|
---|
900 | @items);
|
---|
901 | $body .= ' switch ('.$self->namelen_param().") {\n";
|
---|
902 | # Need to group names of the same length
|
---|
903 | my @by_length;
|
---|
904 | foreach (@items) {
|
---|
905 | push @{$by_length[length $_->{name}]}, $_;
|
---|
906 | }
|
---|
907 | foreach my $i (0 .. $#by_length) {
|
---|
908 | next unless $by_length[$i]; # None of this length
|
---|
909 | $body .= " case $i:\n";
|
---|
910 | if (@{$by_length[$i]} == 1) {
|
---|
911 | my $only_thing = $by_length[$i]->[0];
|
---|
912 | if ($only_thing->{utf8}) {
|
---|
913 | if ($only_thing->{utf8} eq 'yes') {
|
---|
914 | # With utf8 on flag item is passed in element 0
|
---|
915 | $body .= $self->match_clause (undef, [$only_thing]);
|
---|
916 | } else {
|
---|
917 | # With utf8 off flag item is passed in element 1
|
---|
918 | $body .= $self->match_clause (undef, [undef, $only_thing]);
|
---|
919 | }
|
---|
920 | } else {
|
---|
921 | $body .= $self->match_clause (undef, $only_thing);
|
---|
922 | }
|
---|
923 | } elsif (@{$by_length[$i]} < $breakout) {
|
---|
924 | $body .= $self->switch_clause ({indent=>4},
|
---|
925 | $i, $items, @{$by_length[$i]});
|
---|
926 | } else {
|
---|
927 | # Only use the minimal set of parameters actually needed by the types
|
---|
928 | # of the names of this length.
|
---|
929 | my $what = {};
|
---|
930 | foreach (@{$by_length[$i]}) {
|
---|
931 | $what->{$_->{type}} = 1;
|
---|
932 | $what->{''} = 1 if $_->{utf8};
|
---|
933 | }
|
---|
934 | $params = $self->params ($what);
|
---|
935 | push @subs, $self->C_constant ({package=>$package,
|
---|
936 | subname=>"${subname}_$i",
|
---|
937 | default_type => $default_type,
|
---|
938 | types => $what, indent => $indent,
|
---|
939 | breakout => [$i, $items]},
|
---|
940 | @{$by_length[$i]});
|
---|
941 | $body .= " return ${subname}_$i ("
|
---|
942 | # Eg "aTHX_ "
|
---|
943 | . $self->C_constant_prefix_param($params)
|
---|
944 | # Probably "name"
|
---|
945 | . $self->name_param($params);
|
---|
946 | $body .= $self->C_constant_other_params($params);
|
---|
947 | $body .= ");\n";
|
---|
948 | }
|
---|
949 | $body .= " break;\n";
|
---|
950 | }
|
---|
951 | $body .= " }\n";
|
---|
952 | }
|
---|
953 | my $notfound = $self->return_statement_for_notfound();
|
---|
954 | $body .= " $notfound\n" if $notfound;
|
---|
955 | $body .= "}\n";
|
---|
956 | return (@subs, $body);
|
---|
957 | }
|
---|
958 |
|
---|
959 | 1;
|
---|
960 | __END__
|
---|
961 |
|
---|
962 | =back
|
---|
963 |
|
---|
964 | =head1 BUGS
|
---|
965 |
|
---|
966 | Not everything is documented yet.
|
---|
967 |
|
---|
968 | Probably others.
|
---|
969 |
|
---|
970 | =head1 AUTHOR
|
---|
971 |
|
---|
972 | Nicholas Clark <[email protected]> based on the code in C<h2xs> by Larry Wall and
|
---|
973 | others
|
---|