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1 | package ExtUtils::Constant; |
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2 | use vars qw (@ISA $VERSION %XS_Constant %XS_TypeSet @EXPORT_OK %EXPORT_TAGS); |
3 | $VERSION = '0.05'; |
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4 | |
5 | =head1 NAME |
6 | |
7 | ExtUtils::Constant - generate XS code to import C header constants |
8 | |
9 | =head1 SYNOPSIS |
10 | |
11 | use ExtUtils::Constant qw (constant_types C_constant XS_constant); |
12 | print constant_types(); # macro defs |
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13 | foreach (C_constant ("Foo", undef, "IV", undef, undef, undef, |
14 | @names) ) { |
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15 | print $_, "\n"; # C constant subs |
16 | } |
17 | print "MODULE = Foo PACKAGE = Foo\n"; |
18 | print XS_constant ("Foo", {NV => 1, IV => 1}); # XS for Foo::constant |
19 | |
20 | =head1 DESCRIPTION |
21 | |
22 | ExtUtils::Constant facilitates generating C and XS wrapper code to allow |
23 | perl modules to AUTOLOAD constants defined in C library header files. |
24 | It is principally used by the C<h2xs> utility, on which this code is based. |
25 | It doesn't contain the routines to scan header files to extract these |
26 | constants. |
27 | |
28 | =head1 USAGE |
29 | |
30 | Generally one only needs to call the 3 functions shown in the synopsis, |
31 | C<constant_types()>, C<C_constant> and C<XS_constant>. |
32 | |
33 | Currently this module understands the following types. h2xs may only know |
34 | a subset. The sizes of the numeric types are chosen by the C<Configure> |
35 | script at compile time. |
36 | |
37 | =over 4 |
38 | |
39 | =item IV |
40 | |
41 | signed integer, at least 32 bits. |
42 | |
43 | =item UV |
44 | |
45 | unsigned integer, the same size as I<IV> |
46 | |
47 | =item NV |
48 | |
49 | floating point type, probably C<double>, possibly C<long double> |
50 | |
51 | =item PV |
52 | |
53 | NUL terminated string, length will be determined with C<strlen> |
54 | |
55 | =item PVN |
56 | |
57 | A fixed length thing, given as a [pointer, length] pair. If you know the |
58 | length of a string at compile time you may use this instead of I<PV> |
59 | |
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60 | =item YES |
61 | |
62 | Truth. (C<PL_sv_yes>) The value is not needed (and ignored). |
63 | |
64 | =item NO |
65 | |
66 | Defined Falsehood. (C<PL_sv_no>) The value is not needed (and ignored). |
67 | |
68 | =item UNDEF |
69 | |
70 | C<undef>. The value of the macro is not needed. |
71 | |
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72 | =back |
73 | |
74 | =head1 FUNCTIONS |
75 | |
76 | =over 4 |
77 | |
78 | =cut |
79 | |
80 | require 5.006; # I think, for [:cntrl:] in REGEXP |
81 | use warnings; |
82 | use strict; |
83 | use Carp; |
84 | |
85 | use Exporter; |
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86 | use Text::Wrap; |
87 | $Text::Wrap::huge = 'overflow'; |
88 | $Text::Wrap::columns = 80; |
89 | |
90 | @ISA = 'Exporter'; |
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91 | |
92 | %EXPORT_TAGS = ( 'all' => [ qw( |
93 | XS_constant constant_types return_clause memEQ_clause C_stringify |
94 | C_constant autoload |
95 | ) ] ); |
96 | |
97 | @EXPORT_OK = ( @{ $EXPORT_TAGS{'all'} } ); |
98 | |
99 | %XS_Constant = ( |
100 | IV => 'PUSHi(iv)', |
101 | UV => 'PUSHu((UV)iv)', |
102 | NV => 'PUSHn(nv)', |
103 | PV => 'PUSHp(pv, strlen(pv))', |
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104 | PVN => 'PUSHp(pv, iv)', |
105 | YES => 'PUSHs(&PL_sv_yes)', |
106 | NO => 'PUSHs(&PL_sv_no)', |
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107 | UNDEF => '', # implicit undef |
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108 | ); |
109 | |
110 | %XS_TypeSet = ( |
111 | IV => '*iv_return =', |
112 | UV => '*iv_return = (IV)', |
113 | NV => '*nv_return =', |
114 | PV => '*pv_return =', |
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115 | PVN => ['*pv_return =', '*iv_return = (IV)'], |
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116 | YES => undef, |
117 | NO => undef, |
118 | UNDEF => undef, |
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119 | ); |
120 | |
121 | |
122 | =item C_stringify NAME |
123 | |
124 | A function which returns a correctly \ escaped version of the string passed |
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125 | suitable for C's "" or ''. It will also be valid as a perl "" string. |
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126 | |
127 | =cut |
128 | |
129 | # Hopefully make a happy C identifier. |
130 | sub C_stringify { |
131 | local $_ = shift; |
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132 | return unless defined $_; |
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133 | s/\\/\\\\/g; |
134 | s/([\"\'])/\\$1/g; # Grr. fix perl mode. |
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135 | s/\n/\\n/g; # Ensure newlines don't end up in octal |
136 | s/\r/\\r/g; |
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137 | s/\t/\\t/g; |
138 | s/\f/\\f/g; |
139 | s/\a/\\a/g; |
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140 | s/([[:cntrl:]])/sprintf "\\%03o", ord $1/ge; |
141 | s/\177/\\177/g; # DEL doesn't seem to be a [:cntrl:] |
142 | $_; |
143 | } |
144 | |
145 | =item constant_types |
146 | |
147 | A function returning a single scalar with C<#define> definitions for the |
148 | constants used internally between the generated C and XS functions. |
149 | |
150 | =cut |
151 | |
152 | sub constant_types () { |
153 | my $start = 1; |
154 | my @lines; |
155 | push @lines, "#define PERL_constant_NOTFOUND\t$start\n"; $start++; |
156 | push @lines, "#define PERL_constant_NOTDEF\t$start\n"; $start++; |
157 | foreach (sort keys %XS_Constant) { |
158 | push @lines, "#define PERL_constant_IS$_\t$start\n"; $start++; |
159 | } |
160 | push @lines, << 'EOT'; |
161 | |
162 | #ifndef NVTYPE |
163 | typedef double NV; /* 5.6 and later define NVTYPE, and typedef NV to it. */ |
164 | #endif |
165 | EOT |
166 | |
167 | return join '', @lines; |
168 | } |
169 | |
170 | =item memEQ_clause NAME, CHECKED_AT, INDENT |
171 | |
172 | A function to return a suitable C C<if> statement to check whether I<NAME> |
173 | is equal to the C variable C<name>. If I<CHECKED_AT> is defined, then it |
174 | is used to avoid C<memEQ> for short names, or to generate a comment to |
175 | highlight the position of the character in the C<switch> statement. |
176 | |
177 | =cut |
178 | |
179 | sub memEQ_clause { |
180 | # if (memEQ(name, "thingy", 6)) { |
181 | # Which could actually be a character comparison or even "" |
182 | my ($name, $checked_at, $indent) = @_; |
183 | $indent = ' ' x ($indent || 4); |
184 | my $len = length $name; |
185 | |
186 | if ($len < 2) { |
187 | return $indent . "{\n" if (defined $checked_at and $checked_at == 0); |
188 | # We didn't switch, drop through to the code for the 2 character string |
189 | $checked_at = 1; |
190 | } |
191 | if ($len < 3 and defined $checked_at) { |
192 | my $check; |
193 | if ($checked_at == 1) { |
194 | $check = 0; |
195 | } elsif ($checked_at == 0) { |
196 | $check = 1; |
197 | } |
198 | if (defined $check) { |
199 | my $char = C_stringify (substr $name, $check, 1); |
200 | return $indent . "if (name[$check] == '$char') {\n"; |
201 | } |
202 | } |
203 | # Could optimise a memEQ on 3 to 2 single character checks here |
204 | $name = C_stringify ($name); |
205 | my $body = $indent . "if (memEQ(name, \"$name\", $len)) {\n"; |
206 | $body .= $indent . "/* ". (' ' x $checked_at) . '^' |
207 | . (' ' x ($len - $checked_at + length $len)) . " */\n" |
208 | if defined $checked_at; |
209 | return $body; |
210 | } |
211 | |
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212 | =item assign INDENT, TYPE, VALUE... |
213 | |
214 | A function to return a suitable assignment clause. If I<TYPE> is aggregate |
215 | (eg I<PVN> expects both pointer and length) then there should be multiple |
216 | I<VALUE>s for the components. |
217 | |
218 | =cut |
219 | |
220 | # Hmm. value undef to to NOTDEF? value () to do NOTFOUND? |
221 | |
222 | sub assign { |
223 | my $indent = shift; |
224 | my $type = shift; |
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225 | my $clause; |
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226 | die "Can't generate code for type $type" unless exists $XS_TypeSet{$type}; |
227 | my $typeset = $XS_TypeSet{$type}; |
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228 | if (ref $typeset) { |
229 | die "Type $type is aggregate, but only single value given" |
230 | if @_ == 1; |
231 | foreach (0 .. $#$typeset) { |
232 | $clause .= $indent . "$typeset->[$_] $_[$_];\n"; |
233 | } |
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234 | } elsif (defined $typeset) { |
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235 | die "Aggregate value given for type $type" |
236 | if @_ > 1; |
237 | $clause .= $indent . "$typeset $_[0];\n"; |
238 | } |
239 | $clause .= "${indent}return PERL_constant_IS$type;\n"; |
240 | return $clause; |
241 | } |
242 | |
243 | =item return_clause VALUE, TYPE, INDENT, MACRO, DEFAULT |
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244 | |
245 | A function to return a suitable C<#ifdef> clause. I<MACRO> defaults to |
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246 | I<VALUE> when not defined. If I<TYPE> is aggregate (eg I<PVN> expects both |
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247 | pointer and length) then I<VALUE> should be a reference to an array of |
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248 | values in the order expected by the type. C<C_constant> will always call |
249 | this function with I<MACRO> defined, defaulting to the constant's name. |
250 | I<DEFAULT> if defined is an array reference giving default type and and |
251 | value(s) if the clause generated by I<MACRO> doesn't evaluate to true. |
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252 | |
253 | =cut |
254 | |
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255 | sub return_clause ($$$$$) { |
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256 | ##ifdef thingy |
257 | # *iv_return = thingy; |
258 | # return PERL_constant_ISIV; |
259 | ##else |
260 | # return PERL_constant_NOTDEF; |
261 | ##endif |
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262 | my ($value, $type, $indent, $macro, $default) = @_; |
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263 | $macro = $value unless defined $macro; |
264 | $indent = ' ' x ($indent || 6); |
265 | |
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266 | my $clause; |
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267 | |
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268 | ##ifdef thingy |
269 | if (ref $macro) { |
270 | $clause = $macro->[0]; |
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271 | } else { |
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272 | $clause = "#ifdef $macro\n"; |
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273 | } |
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274 | |
275 | # *iv_return = thingy; |
276 | # return PERL_constant_ISIV; |
277 | $clause .= assign ($indent, $type, ref $value ? @$value : $value); |
278 | |
279 | ##else |
280 | $clause .= "#else\n"; |
281 | |
282 | # return PERL_constant_NOTDEF; |
283 | if (!defined $default) { |
284 | $clause .= "${indent}return PERL_constant_NOTDEF;\n"; |
285 | } else { |
286 | $clause .= assign ($indent, ref $default ? @$default : $default); |
287 | } |
288 | |
289 | ##endif |
290 | if (ref $macro) { |
291 | $clause .= $macro->[1]; |
292 | } else { |
293 | $clause .= "#endif\n"; |
294 | } |
295 | return $clause |
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296 | } |
297 | |
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298 | =item switch_clause INDENT, NAMELEN, ITEMHASH, ITEM... |
299 | |
300 | An internal function to generate a suitable C<switch> clause, called by |
301 | C<C_constant> I<ITEM>s are in the hash ref format as given in the description |
302 | of C<C_constant>, and must all have the names of the same length, given by |
303 | I<NAMELEN> (This is not checked). I<ITEMHASH> is a reference to a hash, |
304 | keyed by name, values being the hashrefs in the I<ITEM> list. |
305 | (No parameters are modified, and there can be keys in the I<ITEMHASH> that |
306 | are not in the list of I<ITEM>s without causing problems). |
307 | |
308 | =cut |
309 | |
310 | sub switch_clause { |
311 | my ($indent, $comment, $namelen, $items, @items) = @_; |
312 | $indent = ' ' x ($indent || 2); |
313 | |
314 | my @names = sort map {$_->{name}} @items; |
315 | my $leader = $indent . '/* '; |
316 | my $follower = ' ' x length $leader; |
317 | my $body = $indent . "/* Names all of length $namelen. */\n"; |
318 | if ($comment) { |
319 | $body = wrap ($leader, $follower, $comment) . "\n"; |
320 | $leader = $follower; |
321 | } |
322 | $body .= wrap ($leader, $follower, join (" ", @names) . " */") . "\n"; |
323 | # Figure out what to switch on. |
324 | # (RMS, Spread of jump table, Position, Hashref) |
325 | my @best = (1e38, ~0); |
326 | foreach my $i (0 .. ($namelen - 1)) { |
327 | my ($min, $max) = (~0, 0); |
328 | my %spread; |
329 | foreach (@names) { |
330 | my $char = substr $_, $i, 1; |
331 | my $ord = ord $char; |
332 | $max = $ord if $ord > $max; |
333 | $min = $ord if $ord < $min; |
334 | push @{$spread{$char}}, $_; |
335 | # warn "$_ $char"; |
336 | } |
337 | # I'm going to pick the character to split on that minimises the root |
338 | # mean square of the number of names in each case. Normally this should |
339 | # be the one with the most keys, but it may pick a 7 where the 8 has |
340 | # one long linear search. I'm not sure if RMS or just sum of squares is |
341 | # actually better. |
342 | # $max and $min are for the tie-breaker if the root mean squares match. |
343 | # Assuming that the compiler may be building a jump table for the |
344 | # switch() then try to minimise the size of that jump table. |
345 | # Finally use < not <= so that if it still ties the earliest part of |
346 | # the string wins. Because if that passes but the memEQ fails, it may |
347 | # only need the start of the string to bin the choice. |
348 | # I think. But I'm micro-optimising. :-) |
349 | my $ss; |
350 | $ss += @$_ * @$_ foreach values %spread; |
351 | my $rms = sqrt ($ss / keys %spread); |
352 | if ($rms < $best[0] || ($rms == $best[0] && ($max - $min) < $best[1])) { |
353 | @best = ($rms, $max - $min, $i, \%spread); |
354 | } |
355 | } |
356 | die "Internal error. Failed to pick a switch point for @names" |
357 | unless defined $best[2]; |
358 | # use Data::Dumper; print Dumper (@best); |
359 | my ($offset, $best) = @best[2,3]; |
360 | $body .= $indent . "/* Offset $offset gives the best switch position. */\n"; |
361 | $body .= $indent . "switch (name[$offset]) {\n"; |
362 | foreach my $char (sort keys %$best) { |
363 | $body .= $indent . "case '" . C_stringify ($char) . "':\n"; |
364 | foreach my $name (sort @{$best->{$char}}) { |
365 | my $thisone = $items->{$name}; |
366 | my ($value, $macro, $default) = @$thisone{qw (value macro default)}; |
367 | $value = $name unless defined $value; |
368 | $macro = $name unless defined $macro; |
369 | |
370 | # We have checked this offset. |
371 | $body .= memEQ_clause ($name, $offset, 2 + length $indent); |
372 | $body .= return_clause ($value, $thisone->{type}, 4 + length $indent, |
373 | $macro, $default); |
374 | $body .= $indent . " }\n"; |
375 | } |
376 | $body .= $indent . " break;\n"; |
377 | } |
378 | $body .= $indent . "}\n"; |
379 | return $body; |
380 | } |
381 | |
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382 | =item params WHAT |
383 | |
384 | An internal function. I<WHAT> should be a hashref of types the constant |
385 | function will return. I<params> returns the list of flags C<$use_iv, $use_nv, |
386 | $use_pv> to show which combination of pointers will be needed in the C |
387 | argument list. |
388 | |
389 | =cut |
390 | |
391 | sub params { |
392 | my $what = shift; |
393 | foreach (sort keys %$what) { |
394 | warn "ExtUtils::Constant doesn't know how to handle values of type $_" unless defined $XS_Constant{$_}; |
395 | } |
396 | my $use_iv = $what->{IV} || $what->{UV} || $what->{PVN}; |
397 | my $use_nv = $what->{NV}; |
398 | my $use_pv = $what->{PV} || $what->{PVN}; |
399 | return ($use_iv, $use_nv, $use_pv); |
400 | } |
401 | |
0addb26a |
402 | =item dump_names |
403 | |
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404 | dump_names PACKAGE, SUBNAME, DEFAULT_TYPE, TYPES, INDENT, BREAKOUT, ITEM... |
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405 | |
406 | An internal function to generate the embedded perl code that will regenerate |
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407 | the constant subroutines. Parameters are the same as for C_constant. |
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408 | |
409 | =cut |
410 | |
411 | sub dump_names { |
8ac27563 |
412 | my ($package, $subname, $default_type, $what, $indent, $breakout, @items) |
413 | = @_; |
6d79cad2 |
414 | my (@simple, @complex); |
415 | foreach (@items) { |
416 | my $type = $_->{type} || $default_type; |
417 | if ($type eq $default_type and 0 == ($_->{name} =~ tr/A-Za-z0-9_//c) |
418 | and !defined ($_->{macro}) and !defined ($_->{value}) |
419 | and !defined ($_->{default})) { |
420 | # It's the default type, and the name consists only of A-Za-z0-9_ |
421 | push @simple, $_->{name}; |
422 | } else { |
423 | push @complex, $_; |
424 | } |
425 | } |
426 | my $result = <<"EOT"; |
427 | /* When generated this function returned values for the list of names given |
428 | in this section of perl code. Rather than manually editing these functions |
429 | to add or remove constants, which would result in this comment and section |
430 | of code becoming inaccurate, we recommend that you edit this section of |
431 | code, and use it to regenerate a new set of constant functions which you |
432 | then use to replace the originals. |
433 | |
434 | Regenerate these constant functions by feeding this entire source file to |
435 | perl -x |
436 | |
437 | #!$^X -w |
438 | use ExtUtils::Constant qw (constant_types C_constant XS_constant); |
439 | |
440 | EOT |
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441 | $result .= 'my $types = {map {($_, 1)} qw(' . join (" ", sort keys %$what) |
442 | . ")};\n"; |
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443 | $result .= wrap ("my \@names = (qw(", |
444 | " ", join (" ", sort @simple) . ")"); |
445 | if (@complex) { |
446 | foreach my $item (sort {$a->{name} cmp $b->{name}} @complex) { |
447 | my $name = C_stringify $item->{name}; |
448 | my ($macro, $value, $default) = @$item{qw (macro value default)}; |
449 | my $line = ",\n {name=>\"$name\""; |
450 | $line .= ", type=>\"$item->{type}\"" if defined $item->{type}; |
451 | if (defined $macro) { |
452 | if (ref $macro) { |
453 | $line .= ', macro=>["'. join ('", "', map {C_stringify $_} @$macro) |
454 | . '"]'; |
455 | } else { |
456 | $line .= ", macro=>\"" . C_stringify($macro) . "\""; |
457 | } |
458 | } |
459 | if (defined $value) { |
460 | if (ref $value) { |
461 | $line .= ', value=>["'. join ('", "', map {C_stringify $_} @$value) |
462 | . '"]'; |
463 | } else { |
464 | $line .= ", value=>\"" . C_stringify($value) . "\""; |
465 | } |
466 | } |
467 | if (defined $default) { |
468 | if (ref $default) { |
469 | $line .= ', default=>["'. join ('", "', map {C_stringify $_} |
470 | @$default) |
471 | . '"]'; |
472 | } else { |
473 | $line .= ", default=>\"" . C_stringify($default) . "\""; |
474 | } |
475 | } |
476 | $line .= "}"; |
477 | # Ensure that the enclosing C comment doesn't end |
478 | # by turning */ into *" . "/ |
479 | $line =~ s!\*\/!\*" . "/!gs; |
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480 | # gcc -Wall doesn't like finding /* inside a comment |
481 | $line =~ s!\/\*!/" . "\*!gs; |
6d79cad2 |
482 | $result .= $line; |
483 | } |
484 | } |
485 | $result .= ");\n"; |
486 | |
487 | $result .= <<'EOT'; |
488 | |
489 | print constant_types(); # macro defs |
490 | EOT |
491 | $package = C_stringify($package); |
492 | $result .= |
493 | "foreach (C_constant (\"$package\", '$subname', '$default_type', \$types, "; |
494 | # The form of the indent parameter isn't defined. (Yet) |
495 | if (defined $indent) { |
496 | require Data::Dumper; |
497 | $Data::Dumper::Terse=1; |
8ac27563 |
498 | $Data::Dumper::Terse=1; # Not used once. :-) |
6d79cad2 |
499 | chomp ($indent = Data::Dumper::Dumper ($indent)); |
500 | $result .= $indent; |
501 | } else { |
502 | $result .= 'undef'; |
503 | } |
8ac27563 |
504 | $result .= ", $breakout" . ', @names) ) { |
6d79cad2 |
505 | print $_, "\n"; # C constant subs |
506 | } |
507 | print "#### XS Section:\n"; |
508 | print XS_constant ("' . $package . '", $types); |
509 | __END__ |
510 | */ |
511 | |
512 | '; |
513 | |
514 | $result; |
515 | } |
516 | |
0addb26a |
517 | =item C_constant |
518 | |
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519 | C_constant PACKAGE, SUBNAME, DEFAULT_TYPE, TYPES, INDENT, BREAKOUT, ITEM... |
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520 | |
521 | A function that returns a B<list> of C subroutine definitions that return |
522 | the value and type of constants when passed the name by the XS wrapper. |
523 | I<ITEM...> gives a list of constant names. Each can either be a string, |
524 | which is taken as a C macro name, or a reference to a hash with the following |
525 | keys |
526 | |
527 | =over 8 |
528 | |
529 | =item name |
530 | |
531 | The name of the constant, as seen by the perl code. |
532 | |
533 | =item type |
534 | |
535 | The type of the constant (I<IV>, I<NV> etc) |
536 | |
537 | =item value |
538 | |
539 | A C expression for the value of the constant, or a list of C expressions if |
540 | the type is aggregate. This defaults to the I<name> if not given. |
541 | |
542 | =item macro |
543 | |
544 | The C pre-processor macro to use in the C<#ifdef>. This defaults to the |
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545 | I<name>, and is mainly used if I<value> is an C<enum>. If a reference an |
546 | array is passed then the first element is used in place of the C<#ifdef> |
547 | line, and the second element in place of the C<#endif>. This allows |
548 | pre-processor constructions such as |
549 | |
550 | #if defined (foo) |
551 | #if !defined (bar) |
552 | ... |
553 | #endif |
554 | #endif |
555 | |
556 | to be used to determine if a constant is to be defined. |
557 | |
558 | =item default |
559 | |
560 | Default value to use (instead of C<croak>ing with "your vendor has not |
561 | defined...") to return if the macro isn't defined. Specify a reference to |
562 | an array with type followed by value(s). |
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563 | |
564 | =back |
565 | |
6d79cad2 |
566 | I<PACKAGE> is the name of the package, and is only used in comments inside the |
567 | generated C code. |
568 | |
569 | The next 5 arguments can safely be given as C<undef>, and are mainly used |
af6c647e |
570 | for recursion. I<SUBNAME> defaults to C<constant> if undefined. |
571 | |
572 | I<DEFAULT_TYPE> is the type returned by C<ITEM>s that don't specify their |
573 | type. In turn it defaults to I<IV>. I<TYPES> should be given either as a comma |
574 | separated list of types that the C subroutine C<constant> will generate or as |
575 | a reference to a hash. I<DEFAULT_TYPE> will be added to the list if not |
576 | present, as will any types given in the list of I<ITEM>s. The resultant list |
577 | should be the same list of types that C<XS_constant> is given. [Otherwise |
578 | C<XS_constant> and C<C_constant> may differ in the number of parameters to the |
579 | constant function. I<INDENT> is currently unused and ignored. In future it may |
580 | be used to pass in information used to change the C indentation style used.] |
581 | The best way to maintain consistency is to pass in a hash reference and let |
582 | this function update it. |
583 | |
8ac27563 |
584 | I<BREAKOUT> governs when child functions of I<SUBNAME> are generated. If there |
585 | are I<BREAKOUT> or more I<ITEM>s with the same length of name, then the code |
586 | to switch between them is placed into a function named I<SUBNAME>_I<LEN>, for |
587 | example C<constant_5> for names 5 characters long. The default I<BREAKOUT> is |
588 | 3. A single C<ITEM> is always inlined. |
af6c647e |
589 | |
590 | =cut |
591 | |
8ac27563 |
592 | # The parameter now BREAKOUT was previously documented as: |
593 | # |
594 | # I<NAMELEN> if defined signals that all the I<name>s of the I<ITEM>s are of |
595 | # this length, and that the constant name passed in by perl is checked and |
596 | # also of this length. It is used during recursion, and should be C<undef> |
597 | # unless the caller has checked all the lengths during code generation, and |
598 | # the generated subroutine is only to be called with a name of this length. |
599 | # |
600 | # As you can see it now performs this function during recursion by being a |
601 | # scalar reference. |
602 | |
af6c647e |
603 | sub C_constant { |
8ac27563 |
604 | my ($package, $subname, $default_type, $what, $indent, $breakout, @items) |
605 | = @_; |
606 | my $namelen; |
607 | if (ref $breakout) { |
608 | $namelen = $$breakout; |
609 | } else { |
610 | $breakout ||= 3; |
611 | } |
6d79cad2 |
612 | $package ||= 'Foo'; |
af6c647e |
613 | $subname ||= 'constant'; |
614 | # I'm not using this. But a hashref could be used for full formatting without |
615 | # breaking this API |
6d79cad2 |
616 | # $indent ||= 0; |
af6c647e |
617 | $default_type ||= 'IV'; |
618 | if (!ref $what) { |
619 | # Convert line of the form IV,UV,NV to hash |
620 | $what = {map {$_ => 1} split /,\s*/, ($what || '')}; |
621 | # Figure out what types we're dealing with, and assign all unknowns to the |
622 | # default type |
623 | } |
624 | my %items; |
625 | foreach (@items) { |
626 | my $name; |
627 | if (ref $_) { |
6d79cad2 |
628 | # Make a copy which is a normalised version of the ref passed in. |
af6c647e |
629 | $name = $_->{name}; |
6d79cad2 |
630 | my ($type, $macro, $value, $default) = @$_{qw (type macro value default)}; |
631 | $type ||= $default_type; |
632 | $what->{$type} = 1; |
633 | $_ = {name=>$name, type=>$type}; |
634 | |
635 | undef $macro if defined $macro and $macro eq $name; |
636 | $_->{macro} = $macro if defined $macro; |
637 | undef $value if defined $value and $value eq $name; |
638 | $_->{value} = $value if defined $value; |
639 | $_->{default} = $default if defined $default; |
af6c647e |
640 | } else { |
641 | $name = $_; |
642 | $_ = {name=>$_, type=>$default_type}; |
643 | $what->{$default_type} = 1; |
644 | } |
645 | warn "ExtUtils::Constant doesn't know how to handle values of type $_ used in macro $name" unless defined $XS_Constant{$_->{type}}; |
646 | if (exists $items{$name}) { |
647 | die "Multiple definitions for macro $name"; |
648 | } |
649 | $items{$name} = $_; |
650 | } |
651 | my ($use_iv, $use_nv, $use_pv) = params ($what); |
652 | |
653 | my ($body, @subs) = "static int\n$subname (const char *name"; |
654 | $body .= ", STRLEN len" unless defined $namelen; |
655 | $body .= ", IV *iv_return" if $use_iv; |
656 | $body .= ", NV *nv_return" if $use_nv; |
657 | $body .= ", const char **pv_return" if $use_pv; |
658 | $body .= ") {\n"; |
659 | |
6d79cad2 |
660 | if (defined $namelen) { |
661 | # We are a child subroutine. Print the simple description |
8ac27563 |
662 | my $comment = 'When generated this function returned values for the list' |
663 | . ' of names given here. However, subsequent manual editing may have' |
664 | . ' added or removed some.'; |
665 | $body .= switch_clause (2, $comment, $namelen, \%items, @items); |
af6c647e |
666 | } else { |
667 | # We are the top level. |
668 | $body .= " /* Initially switch on the length of the name. */\n"; |
6d79cad2 |
669 | $body .= dump_names ($package, $subname, $default_type, $what, $indent, |
8ac27563 |
670 | $breakout, @items); |
af6c647e |
671 | $body .= " switch (len) {\n"; |
672 | # Need to group names of the same length |
673 | my @by_length; |
674 | foreach (@items) { |
675 | push @{$by_length[length $_->{name}]}, $_; |
676 | } |
677 | foreach my $i (0 .. $#by_length) { |
678 | next unless $by_length[$i]; # None of this length |
679 | $body .= " case $i:\n"; |
680 | if (@{$by_length[$i]} == 1) { |
681 | my $thisone = $by_length[$i]->[0]; |
6d79cad2 |
682 | my ($name, $value, $macro, $default) |
683 | = @$thisone{qw (name value macro default)}; |
af6c647e |
684 | $value = $name unless defined $value; |
685 | $macro = $name unless defined $macro; |
686 | |
687 | $body .= memEQ_clause ($name); |
6d79cad2 |
688 | $body .= return_clause ($value, $thisone->{type}, undef, $macro, |
689 | $default); |
af6c647e |
690 | $body .= " }\n"; |
8ac27563 |
691 | } elsif (@{$by_length[$i]} < $breakout) { |
692 | $body .= switch_clause (4, '', $i, \%items, @{$by_length[$i]}); |
af6c647e |
693 | } else { |
6d79cad2 |
694 | push @subs, C_constant ($package, "${subname}_$i", $default_type, |
8ac27563 |
695 | $what, $indent, \$i, @{$by_length[$i]}); |
af6c647e |
696 | $body .= " return ${subname}_$i (name"; |
697 | $body .= ", iv_return" if $use_iv; |
698 | $body .= ", nv_return" if $use_nv; |
699 | $body .= ", pv_return" if $use_pv; |
700 | $body .= ");\n"; |
701 | } |
702 | $body .= " break;\n"; |
703 | } |
704 | $body .= " }\n"; |
705 | } |
706 | $body .= " return PERL_constant_NOTFOUND;\n}\n"; |
707 | return (@subs, $body); |
708 | } |
709 | |
710 | =item XS_constant PACKAGE, TYPES, SUBNAME, C_SUBNAME |
711 | |
712 | A function to generate the XS code to implement the perl subroutine |
713 | I<PACKAGE>::constant used by I<PACKAGE>::AUTOLOAD to load constants. |
714 | This XS code is a wrapper around a C subroutine usually generated by |
715 | C<C_constant>, and usually named C<constant>. |
716 | |
717 | I<TYPES> should be given either as a comma separated list of types that the |
718 | C subroutine C<constant> will generate or as a reference to a hash. It should |
719 | be the same list of types as C<C_constant> was given. |
720 | [Otherwise C<XS_constant> and C<C_constant> may have different ideas about |
721 | the number of parameters passed to the C function C<constant>] |
722 | |
723 | You can call the perl visible subroutine something other than C<constant> if |
724 | you give the parameter I<SUBNAME>. The C subroutine it calls defaults to the |
725 | the name of the perl visible subroutine, unless you give the parameter |
726 | I<C_SUBNAME>. |
727 | |
728 | =cut |
729 | |
730 | sub XS_constant { |
731 | my $package = shift; |
732 | my $what = shift; |
733 | my $subname = shift; |
734 | my $C_subname = shift; |
735 | $subname ||= 'constant'; |
736 | $C_subname ||= $subname; |
737 | |
738 | if (!ref $what) { |
739 | # Convert line of the form IV,UV,NV to hash |
740 | $what = {map {$_ => 1} split /,\s*/, ($what)}; |
741 | } |
742 | my ($use_iv, $use_nv, $use_pv) = params ($what); |
743 | my $type; |
744 | |
745 | my $xs = <<"EOT"; |
746 | void |
747 | $subname(sv) |
748 | PREINIT: |
749 | #ifdef dXSTARG |
750 | dXSTARG; /* Faster if we have it. */ |
751 | #else |
752 | dTARGET; |
753 | #endif |
754 | STRLEN len; |
755 | int type; |
756 | EOT |
757 | |
758 | if ($use_iv) { |
759 | $xs .= " IV iv;\n"; |
760 | } else { |
761 | $xs .= " /* IV\t\tiv;\tUncomment this if you need to return IVs */\n"; |
762 | } |
763 | if ($use_nv) { |
764 | $xs .= " NV nv;\n"; |
765 | } else { |
766 | $xs .= " /* NV\t\tnv;\tUncomment this if you need to return NVs */\n"; |
767 | } |
768 | if ($use_pv) { |
769 | $xs .= " const char *pv;\n"; |
770 | } else { |
771 | $xs .= |
772 | " /* const char\t*pv;\tUncomment this if you need to return PVs */\n"; |
773 | } |
774 | |
775 | $xs .= << 'EOT'; |
776 | INPUT: |
777 | SV * sv; |
778 | const char * s = SvPV(sv, len); |
779 | PPCODE: |
780 | EOT |
781 | |
782 | if ($use_iv xor $use_nv) { |
783 | $xs .= << "EOT"; |
784 | /* Change this to $C_subname(s, len, &iv, &nv); |
785 | if you need to return both NVs and IVs */ |
786 | EOT |
787 | } |
788 | $xs .= " type = $C_subname(s, len"; |
789 | $xs .= ', &iv' if $use_iv; |
790 | $xs .= ', &nv' if $use_nv; |
791 | $xs .= ', &pv' if $use_pv; |
792 | $xs .= ");\n"; |
793 | |
794 | $xs .= << "EOT"; |
795 | /* Return 1 or 2 items. First is error message, or undef if no error. |
796 | Second, if present, is found value */ |
797 | switch (type) { |
798 | case PERL_constant_NOTFOUND: |
799 | sv = sv_2mortal(newSVpvf("%s is not a valid $package macro", s)); |
6d79cad2 |
800 | PUSHs(sv); |
af6c647e |
801 | break; |
802 | case PERL_constant_NOTDEF: |
803 | sv = sv_2mortal(newSVpvf( |
8ac27563 |
804 | "Your vendor has not defined $package macro %s, used", s)); |
6d79cad2 |
805 | PUSHs(sv); |
af6c647e |
806 | break; |
807 | EOT |
808 | |
809 | foreach $type (sort keys %XS_Constant) { |
810 | $xs .= "\t/* Uncomment this if you need to return ${type}s\n" |
811 | unless $what->{$type}; |
8ac27563 |
812 | $xs .= " case PERL_constant_IS$type:\n"; |
813 | if (length $XS_Constant{$type}) { |
814 | $xs .= << "EOT"; |
af6c647e |
815 | EXTEND(SP, 1); |
816 | PUSHs(&PL_sv_undef); |
817 | $XS_Constant{$type}; |
af6c647e |
818 | EOT |
8ac27563 |
819 | } else { |
820 | # Do nothing. return (), which will be correctly interpreted as |
821 | # (undef, undef) |
822 | } |
823 | $xs .= " break;\n"; |
af6c647e |
824 | unless ($what->{$type}) { |
825 | chop $xs; # Yes, another need for chop not chomp. |
826 | $xs .= " */\n"; |
827 | } |
828 | } |
829 | $xs .= << "EOT"; |
830 | default: |
831 | sv = sv_2mortal(newSVpvf( |
8ac27563 |
832 | "Unexpected return type %d while processing $package macro %s, used", |
af6c647e |
833 | type, s)); |
6d79cad2 |
834 | PUSHs(sv); |
af6c647e |
835 | } |
836 | EOT |
837 | |
838 | return $xs; |
839 | } |
840 | |
841 | |
6d79cad2 |
842 | =item autoload PACKAGE, VERSION, AUTOLOADER |
af6c647e |
843 | |
844 | A function to generate the AUTOLOAD subroutine for the module I<PACKAGE> |
845 | I<VERSION> is the perl version the code should be backwards compatible with. |
6d79cad2 |
846 | It defaults to the version of perl running the subroutine. If I<AUTOLOADER> |
847 | is true, the AUTOLOAD subroutine falls back on AutoLoader::AUTOLOAD for all |
848 | names that the constant() routine doesn't recognise. |
af6c647e |
849 | |
850 | =cut |
851 | |
6d79cad2 |
852 | # ' # Grr. syntax highlighters that don't grok pod. |
853 | |
af6c647e |
854 | sub autoload { |
6d79cad2 |
855 | my ($module, $compat_version, $autoloader) = @_; |
af6c647e |
856 | $compat_version ||= $]; |
857 | croak "Can't maintain compatibility back as far as version $compat_version" |
858 | if $compat_version < 5; |
6d79cad2 |
859 | my $func = "sub AUTOLOAD {\n" |
860 | . " # This AUTOLOAD is used to 'autoload' constants from the constant()\n" |
861 | . " # XS function."; |
862 | $func .= " If a constant is not found then control is passed\n" |
863 | . " # to the AUTOLOAD in AutoLoader." if $autoloader; |
864 | |
865 | |
866 | $func .= "\n\n" |
867 | . " my \$constname;\n"; |
868 | $func .= |
869 | " our \$AUTOLOAD;\n" if ($compat_version >= 5.006); |
870 | |
871 | $func .= <<"EOT"; |
af6c647e |
872 | (\$constname = \$AUTOLOAD) =~ s/.*:://; |
873 | croak "&${module}::constant not defined" if \$constname eq 'constant'; |
874 | my (\$error, \$val) = constant(\$constname); |
6d79cad2 |
875 | EOT |
876 | |
877 | if ($autoloader) { |
878 | $func .= <<'EOT'; |
879 | if ($error) { |
880 | if ($error =~ /is not a valid/) { |
881 | $AutoLoader::AUTOLOAD = $AUTOLOAD; |
af6c647e |
882 | goto &AutoLoader::AUTOLOAD; |
883 | } else { |
6d79cad2 |
884 | croak $error; |
af6c647e |
885 | } |
886 | } |
6d79cad2 |
887 | EOT |
888 | } else { |
889 | $func .= |
890 | " if (\$error) { croak \$error; }\n"; |
891 | } |
892 | |
893 | $func .= <<'END'; |
af6c647e |
894 | { |
895 | no strict 'refs'; |
896 | # Fixed between 5.005_53 and 5.005_61 |
6d79cad2 |
897 | #XXX if ($] >= 5.00561) { |
898 | #XXX *$AUTOLOAD = sub () { $val }; |
af6c647e |
899 | #XXX } |
900 | #XXX else { |
6d79cad2 |
901 | *$AUTOLOAD = sub { $val }; |
af6c647e |
902 | #XXX } |
903 | } |
6d79cad2 |
904 | goto &$AUTOLOAD; |
af6c647e |
905 | } |
906 | |
907 | END |
908 | |
6d79cad2 |
909 | return $func; |
af6c647e |
910 | } |
911 | 1; |
912 | __END__ |
913 | |
914 | =back |
915 | |
916 | =head1 AUTHOR |
917 | |
918 | Nicholas Clark <nick@ccl4.org> based on the code in C<h2xs> by Larry Wall and |
919 | others |
920 | |
921 | =cut |