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005c1a0e |
1 | package ExtUtils::Liblist; |
8a1da95f |
2 | use vars qw($VERSION); |
005c1a0e |
3 | # Broken out of MakeMaker from version 4.11 |
4 | |
84902520 |
5 | $VERSION = substr q$Revision: 1.25 $, 10; |
f1387719 |
6 | |
005c1a0e |
7 | use Config; |
8f1aa56b |
8 | use Cwd 'cwd'; |
4633a7c4 |
9 | use File::Basename; |
10 | |
005c1a0e |
11 | sub ext { |
3e3baf6d |
12 | if ($^O eq 'VMS') { return &_vms_ext; } |
13 | elsif($^O eq 'MSWin32') { return &_win32_ext; } |
14 | else { return &_unix_os2_ext; } |
55497cff |
15 | } |
16 | |
17 | sub _unix_os2_ext { |
e611f912 |
18 | my($self,$potential_libs, $verbose) = @_; |
f1387719 |
19 | if ($^O =~ 'os2' and $Config{libs}) { |
4e68a208 |
20 | # Dynamic libraries are not transitive, so we may need including |
21 | # the libraries linked against perl.dll again. |
22 | |
23 | $potential_libs .= " " if $potential_libs; |
24 | $potential_libs .= $Config{libs}; |
25 | } |
4633a7c4 |
26 | return ("", "", "", "") unless $potential_libs; |
fb73857a |
27 | warn "Potential libraries are '$potential_libs':\n" if $verbose; |
005c1a0e |
28 | |
29 | my($so) = $Config{'so'}; |
30 | my($libs) = $Config{'libs'}; |
55497cff |
31 | my $Config_libext = $Config{lib_ext} || ".a"; |
32 | |
005c1a0e |
33 | |
34 | # compute $extralibs, $bsloadlibs and $ldloadlibs from |
35 | # $potential_libs |
36 | # this is a rewrite of Andy Dougherty's extliblist in perl |
005c1a0e |
37 | |
38 | my(@searchpath); # from "-L/path" entries in $potential_libs |
39 | my(@libpath) = split " ", $Config{'libpth'}; |
4633a7c4 |
40 | my(@ldloadlibs, @bsloadlibs, @extralibs, @ld_run_path, %ld_run_path_seen); |
005c1a0e |
41 | my($fullname, $thislib, $thispth, @fullname); |
8f1aa56b |
42 | my($pwd) = cwd(); # from Cwd.pm |
005c1a0e |
43 | my($found) = 0; |
44 | |
45 | foreach $thislib (split ' ', $potential_libs){ |
46 | |
47 | # Handle possible linker path arguments. |
48 | if ($thislib =~ s/^(-[LR])//){ # save path flag type |
49 | my($ptype) = $1; |
50 | unless (-d $thislib){ |
fb73857a |
51 | warn "$ptype$thislib ignored, directory does not exist\n" |
e611f912 |
52 | if $verbose; |
005c1a0e |
53 | next; |
54 | } |
f1387719 |
55 | unless ($self->file_name_is_absolute($thislib)) { |
fb73857a |
56 | warn "Warning: $ptype$thislib changed to $ptype$pwd/$thislib\n"; |
f1387719 |
57 | $thislib = $self->catdir($pwd,$thislib); |
005c1a0e |
58 | } |
59 | push(@searchpath, $thislib); |
60 | push(@extralibs, "$ptype$thislib"); |
61 | push(@ldloadlibs, "$ptype$thislib"); |
62 | next; |
63 | } |
64 | |
65 | # Handle possible library arguments. |
66 | unless ($thislib =~ s/^-l//){ |
fb73857a |
67 | warn "Unrecognized argument in LIBS ignored: '$thislib'\n"; |
005c1a0e |
68 | next; |
69 | } |
70 | |
71 | my($found_lib)=0; |
72 | foreach $thispth (@searchpath, @libpath){ |
73 | |
74 | # Try to find the full name of the library. We need this to |
75 | # determine whether it's a dynamically-loadable library or not. |
76 | # This tends to be subject to various os-specific quirks. |
77 | # For gcc-2.6.2 on linux (March 1995), DLD can not load |
78 | # .sa libraries, with the exception of libm.sa, so we |
79 | # deliberately skip them. |
4e1fac24 |
80 | if (@fullname = |
81 | $self->lsdir($thispth,"^\Qlib$thislib.$so.\E[0-9]+")){ |
005c1a0e |
82 | # Take care that libfoo.so.10 wins against libfoo.so.9. |
83 | # Compare two libraries to find the most recent version |
84 | # number. E.g. if you have libfoo.so.9.0.7 and |
85 | # libfoo.so.10.1, first convert all digits into two |
86 | # decimal places. Then we'll add ".00" to the shorter |
87 | # strings so that we're comparing strings of equal length |
88 | # Thus we'll compare libfoo.so.09.07.00 with |
89 | # libfoo.so.10.01.00. Some libraries might have letters |
90 | # in the version. We don't know what they mean, but will |
91 | # try to skip them gracefully -- we'll set any letter to |
92 | # '0'. Finally, sort in reverse so we can take the |
93 | # first element. |
94 | |
95 | #TODO: iterate through the directory instead of sorting |
96 | |
97 | $fullname = "$thispth/" . |
98 | (sort { my($ma) = $a; |
99 | my($mb) = $b; |
100 | $ma =~ tr/A-Za-z/0/s; |
101 | $ma =~ s/\b(\d)\b/0$1/g; |
102 | $mb =~ tr/A-Za-z/0/s; |
103 | $mb =~ s/\b(\d)\b/0$1/g; |
104 | while (length($ma) < length($mb)) { $ma .= ".00"; } |
105 | while (length($mb) < length($ma)) { $mb .= ".00"; } |
106 | # Comparison deliberately backwards |
107 | $mb cmp $ma;} @fullname)[0]; |
108 | } elsif (-f ($fullname="$thispth/lib$thislib.$so") |
109 | && (($Config{'dlsrc'} ne "dl_dld.xs") || ($thislib eq "m"))){ |
4633a7c4 |
110 | } elsif (-f ($fullname="$thispth/lib${thislib}_s$Config_libext") |
005c1a0e |
111 | && ($thislib .= "_s") ){ # we must explicitly use _s version |
4633a7c4 |
112 | } elsif (-f ($fullname="$thispth/lib$thislib$Config_libext")){ |
864a5fa8 |
113 | } elsif (-f ($fullname="$thispth/$thislib$Config_libext")){ |
4633a7c4 |
114 | } elsif (-f ($fullname="$thispth/Slib$thislib$Config_libext")){ |
8f1aa56b |
115 | } elsif ($^O eq 'dgux' |
c07a80fd |
116 | && -l ($fullname="$thispth/lib$thislib$Config_libext") |
117 | && readlink($fullname) =~ /^elink:/) { |
118 | # Some of DG's libraries look like misconnected symbolic |
119 | # links, but development tools can follow them. (They |
120 | # look like this: |
121 | # |
122 | # libm.a -> elink:${SDE_PATH:-/usr}/sde/\ |
123 | # ${TARGET_BINARY_INTERFACE:-m88kdgux}/usr/lib/libm.a |
124 | # |
125 | # , the compilation tools expand the environment variables.) |
005c1a0e |
126 | } else { |
fb73857a |
127 | warn "$thislib not found in $thispth\n" if $verbose; |
005c1a0e |
128 | next; |
129 | } |
fb73857a |
130 | warn "'-l$thislib' found at $fullname\n" if $verbose; |
4633a7c4 |
131 | my($fullnamedir) = dirname($fullname); |
132 | push @ld_run_path, $fullnamedir unless $ld_run_path_seen{$fullnamedir}++; |
005c1a0e |
133 | $found++; |
134 | $found_lib++; |
135 | |
136 | # Now update library lists |
137 | |
138 | # what do we know about this library... |
4633a7c4 |
139 | my $is_dyna = ($fullname !~ /\Q$Config_libext\E$/); |
4e68a208 |
140 | my $in_perl = ($libs =~ /\B-l\Q$ {thislib}\E\b/s); |
005c1a0e |
141 | |
142 | # Do not add it into the list if it is already linked in |
143 | # with the main perl executable. |
974f612f |
144 | # We have to special-case the NeXT, because math and ndbm |
145 | # are both in libsys_s |
005c1a0e |
146 | unless ($in_perl || |
974f612f |
147 | ($Config{'osname'} eq 'next' && |
148 | ($thislib eq 'm' || $thislib eq 'ndbm')) ){ |
005c1a0e |
149 | push(@extralibs, "-l$thislib"); |
150 | } |
151 | |
152 | # We might be able to load this archive file dynamically |
974f612f |
153 | if ( ($Config{'dlsrc'} =~ /dl_next/ && $Config{'osvers'} lt '4_0') |
154 | || ($Config{'dlsrc'} =~ /dl_dld/) ) |
155 | { |
005c1a0e |
156 | # We push -l$thislib instead of $fullname because |
157 | # it avoids hardwiring a fixed path into the .bs file. |
158 | # Mkbootstrap will automatically add dl_findfile() to |
159 | # the .bs file if it sees a name in the -l format. |
160 | # USE THIS, when dl_findfile() is fixed: |
161 | # push(@bsloadlibs, "-l$thislib"); |
162 | # OLD USE WAS while checking results against old_extliblist |
163 | push(@bsloadlibs, "$fullname"); |
164 | } else { |
165 | if ($is_dyna){ |
166 | # For SunOS4, do not add in this shared library if |
167 | # it is already linked in the main perl executable |
168 | push(@ldloadlibs, "-l$thislib") |
8f1aa56b |
169 | unless ($in_perl and $^O eq 'sunos'); |
005c1a0e |
170 | } else { |
171 | push(@ldloadlibs, "-l$thislib"); |
172 | } |
173 | } |
174 | last; # found one here so don't bother looking further |
175 | } |
fb73857a |
176 | warn "Note (probably harmless): " |
f3d9a6ba |
177 | ."No library found for -l$thislib\n" |
005c1a0e |
178 | unless $found_lib>0; |
179 | } |
4633a7c4 |
180 | return ('','','','') unless $found; |
181 | ("@extralibs", "@bsloadlibs", "@ldloadlibs",join(":",@ld_run_path)); |
005c1a0e |
182 | } |
183 | |
3e3baf6d |
184 | sub _win32_ext { |
e611f912 |
185 | my($self, $potential_libs, $verbose) = @_; |
3e3baf6d |
186 | |
187 | # If user did not supply a list, we punt. |
188 | # (caller should probably use the list in $Config{libs}) |
189 | return ("", "", "", "") unless $potential_libs; |
190 | |
191 | my($so) = $Config{'so'}; |
192 | my($libs) = $Config{'libs'}; |
193 | my($libpth) = $Config{'libpth'}; |
194 | my($libext) = $Config{'lib_ext'} || ".lib"; |
195 | |
196 | if ($libs and $potential_libs !~ /:nodefault/i) { |
197 | # If Config.pm defines a set of default libs, we always |
198 | # tack them on to the user-supplied list, unless the user |
199 | # specified :nodefault |
200 | |
201 | $potential_libs .= " " if $potential_libs; |
202 | $potential_libs .= $libs; |
203 | } |
fb73857a |
204 | warn "Potential libraries are '$potential_libs':\n" if $verbose; |
3e3baf6d |
205 | |
206 | # compute $extralibs from $potential_libs |
207 | |
208 | my(@searchpath); # from "-L/path" entries in $potential_libs |
209 | my(@libpath) = split " ", $libpth; |
210 | my(@extralibs); |
211 | my($fullname, $thislib, $thispth); |
212 | my($pwd) = cwd(); # from Cwd.pm |
213 | my($lib) = ''; |
214 | my($found) = 0; |
215 | |
216 | foreach $thislib (split ' ', $potential_libs){ |
217 | |
218 | # Handle possible linker path arguments. |
219 | if ($thislib =~ s/^-L// and not -d $thislib) { |
fb73857a |
220 | warn "-L$thislib ignored, directory does not exist\n" |
e611f912 |
221 | if $verbose; |
3e3baf6d |
222 | next; |
223 | } |
224 | elsif (-d $thislib) { |
225 | unless ($self->file_name_is_absolute($thislib)) { |
fb73857a |
226 | warn "Warning: -L$thislib changed to -L$pwd/$thislib\n"; |
3e3baf6d |
227 | $thislib = $self->catdir($pwd,$thislib); |
228 | } |
229 | push(@searchpath, $thislib); |
230 | next; |
231 | } |
232 | |
233 | # Handle possible library arguments. |
234 | $thislib =~ s/^-l//; |
235 | $thislib .= $libext if $thislib !~ /\Q$libext\E$/i; |
236 | |
237 | my($found_lib)=0; |
238 | foreach $thispth (@searchpath, @libpath){ |
239 | unless (-f ($fullname="$thispth\\$thislib")) { |
fb73857a |
240 | warn "$thislib not found in $thispth\n" if $verbose; |
3e3baf6d |
241 | next; |
242 | } |
fb73857a |
243 | warn "'$thislib' found at $fullname\n" if $verbose; |
3e3baf6d |
244 | $found++; |
245 | $found_lib++; |
246 | push(@extralibs, $fullname); |
247 | last; |
248 | } |
fb73857a |
249 | warn "Note (probably harmless): " |
3e3baf6d |
250 | ."No library found for '$thislib'\n" |
251 | unless $found_lib>0; |
252 | } |
253 | return ('','','','') unless $found; |
254 | $lib = join(' ',@extralibs); |
fb73857a |
255 | warn "Result: $lib\n" if $verbose; |
3e3baf6d |
256 | wantarray ? ($lib, '', $lib, '') : $lib; |
257 | } |
258 | |
55497cff |
259 | |
260 | sub _vms_ext { |
261 | my($self, $potential_libs,$verbose) = @_; |
262 | return ('', '', '', '') unless $potential_libs; |
263 | |
264 | my(@dirs,@libs,$dir,$lib,%sh,%olb,%obj); |
265 | my $cwd = cwd(); |
266 | my($so,$lib_ext,$obj_ext) = @Config{'so','lib_ext','obj_ext'}; |
267 | # List of common Unix library names and there VMS equivalents |
268 | # (VMS equivalent of '' indicates that the library is automatially |
269 | # searched by the linker, and should be skipped here.) |
270 | my %libmap = ( 'm' => '', 'f77' => '', 'F77' => '', 'V77' => '', 'c' => '', |
271 | 'malloc' => '', 'crypt' => '', 'resolv' => '', 'c_s' => '', |
272 | 'socket' => '', 'X11' => 'DECW$XLIBSHR', |
273 | 'Xt' => 'DECW$XTSHR', 'Xm' => 'DECW$XMLIBSHR', |
274 | 'Xmu' => 'DECW$XMULIBSHR'); |
275 | if ($Config{'vms_cc_type'} ne 'decc') { $libmap{'curses'} = 'VAXCCURSE'; } |
276 | |
fb73857a |
277 | warn "Potential libraries are '$potential_libs'\n" if $verbose; |
55497cff |
278 | |
279 | # First, sort out directories and library names in the input |
280 | foreach $lib (split ' ',$potential_libs) { |
281 | push(@dirs,$1), next if $lib =~ /^-L(.*)/; |
282 | push(@dirs,$lib), next if $lib =~ /[:>\]]$/; |
283 | push(@dirs,$lib), next if -d $lib; |
284 | push(@libs,$1), next if $lib =~ /^-l(.*)/; |
285 | push(@libs,$lib); |
286 | } |
287 | push(@dirs,split(' ',$Config{'libpth'})); |
288 | |
289 | # Now make sure we've got VMS-syntax absolute directory specs |
290 | # (We don't, however, check whether someone's hidden a relative |
291 | # path in a logical name.) |
292 | foreach $dir (@dirs) { |
293 | unless (-d $dir) { |
fb73857a |
294 | warn "Skipping nonexistent Directory $dir\n" if $verbose > 1; |
55497cff |
295 | $dir = ''; |
296 | next; |
297 | } |
fb73857a |
298 | warn "Resolving directory $dir\n" if $verbose; |
55497cff |
299 | if ($self->file_name_is_absolute($dir)) { $dir = $self->fixpath($dir,1); } |
300 | else { $dir = $self->catdir($cwd,$dir); } |
301 | } |
302 | @dirs = grep { length($_) } @dirs; |
303 | unshift(@dirs,''); # Check each $lib without additions first |
304 | |
305 | LIB: foreach $lib (@libs) { |
306 | if (exists $libmap{$lib}) { |
307 | next unless length $libmap{$lib}; |
308 | $lib = $libmap{$lib}; |
309 | } |
310 | |
311 | my(@variants,$variant,$name,$test,$cand); |
312 | my($ctype) = ''; |
313 | |
314 | # If we don't have a file type, consider it a possibly abbreviated name and |
315 | # check for common variants. We try these first to grab libraries before |
316 | # a like-named executable image (e.g. -lperl resolves to perlshr.exe |
317 | # before perl.exe). |
318 | if ($lib !~ /\.[^:>\]]*$/) { |
319 | push(@variants,"${lib}shr","${lib}rtl","${lib}lib"); |
320 | push(@variants,"lib$lib") if $lib !~ /[:>\]]/; |
321 | } |
322 | push(@variants,$lib); |
fb73857a |
323 | warn "Looking for $lib\n" if $verbose; |
55497cff |
324 | foreach $variant (@variants) { |
325 | foreach $dir (@dirs) { |
326 | my($type); |
327 | |
328 | $name = "$dir$variant"; |
fb73857a |
329 | warn "\tChecking $name\n" if $verbose > 2; |
55497cff |
330 | if (-f ($test = VMS::Filespec::rmsexpand($name))) { |
331 | # It's got its own suffix, so we'll have to figure out the type |
332 | if ($test =~ /(?:$so|exe)$/i) { $type = 'sh'; } |
333 | elsif ($test =~ /(?:$lib_ext|olb)$/i) { $type = 'olb'; } |
334 | elsif ($test =~ /(?:$obj_ext|obj)$/i) { |
fb73857a |
335 | warn "Note (probably harmless): " |
f3d9a6ba |
336 | ."Plain object file $test found in library list\n"; |
55497cff |
337 | $type = 'obj'; |
338 | } |
339 | else { |
fb73857a |
340 | warn "Note (probably harmless): " |
f3d9a6ba |
341 | ."Unknown library type for $test; assuming shared\n"; |
55497cff |
342 | $type = 'sh'; |
343 | } |
344 | } |
345 | elsif (-f ($test = VMS::Filespec::rmsexpand($name,$so)) or |
346 | -f ($test = VMS::Filespec::rmsexpand($name,'.exe'))) { |
347 | $type = 'sh'; |
348 | $name = $test unless $test =~ /exe;?\d*$/i; |
349 | } |
350 | elsif (not length($ctype) and # If we've got a lib already, don't bother |
351 | ( -f ($test = VMS::Filespec::rmsexpand($name,$lib_ext)) or |
352 | -f ($test = VMS::Filespec::rmsexpand($name,'.olb')))) { |
353 | $type = 'olb'; |
354 | $name = $test unless $test =~ /olb;?\d*$/i; |
355 | } |
356 | elsif (not length($ctype) and # If we've got a lib already, don't bother |
357 | ( -f ($test = VMS::Filespec::rmsexpand($name,$obj_ext)) or |
358 | -f ($test = VMS::Filespec::rmsexpand($name,'.obj')))) { |
fb73857a |
359 | warn "Note (probably harmless): " |
f3d9a6ba |
360 | ."Plain object file $test found in library list\n"; |
55497cff |
361 | $type = 'obj'; |
362 | $name = $test unless $test =~ /obj;?\d*$/i; |
363 | } |
364 | if (defined $type) { |
365 | $ctype = $type; $cand = $name; |
366 | last if $ctype eq 'sh'; |
367 | } |
368 | } |
369 | if ($ctype) { |
370 | eval '$' . $ctype . "{'$cand'}++"; |
371 | die "Error recording library: $@" if $@; |
fb73857a |
372 | warn "\tFound as $cand (really $test), type $ctype\n" if $verbose > 1; |
55497cff |
373 | next LIB; |
374 | } |
375 | } |
fb73857a |
376 | warn "Note (probably harmless): " |
f3d9a6ba |
377 | ."No library found for $lib\n"; |
55497cff |
378 | } |
379 | |
380 | @libs = sort keys %obj; |
381 | # This has to precede any other CRTLs, so just make it first |
382 | if ($olb{VAXCCURSE}) { |
383 | push(@libs,"$olb{VAXCCURSE}/Library"); |
384 | delete $olb{VAXCCURSE}; |
385 | } |
386 | push(@libs, map { "$_/Library" } sort keys %olb); |
387 | push(@libs, map { "$_/Share" } sort keys %sh); |
388 | $lib = join(' ',@libs); |
fb73857a |
389 | warn "Result: $lib\n" if $verbose; |
55497cff |
390 | wantarray ? ($lib, '', $lib, '') : $lib; |
391 | } |
392 | |
005c1a0e |
393 | 1; |
c2e89b3d |
394 | |
864a5fa8 |
395 | __END__ |
cb1a09d0 |
396 | |
864a5fa8 |
397 | =head1 NAME |
398 | |
399 | ExtUtils::Liblist - determine libraries to use and how to use them |
400 | |
401 | =head1 SYNOPSIS |
402 | |
403 | C<require ExtUtils::Liblist;> |
404 | |
e611f912 |
405 | C<ExtUtils::Liblist::ext($self, $potential_libs, $verbose);> |
864a5fa8 |
406 | |
407 | =head1 DESCRIPTION |
408 | |
409 | This utility takes a list of libraries in the form C<-llib1 -llib2 |
410 | -llib3> and prints out lines suitable for inclusion in an extension |
411 | Makefile. Extra library paths may be included with the form |
412 | C<-L/another/path> this will affect the searches for all subsequent |
413 | libraries. |
414 | |
415 | It returns an array of four scalar values: EXTRALIBS, BSLOADLIBS, |
3e3baf6d |
416 | LDLOADLIBS, and LD_RUN_PATH. Some of these don't mean anything |
417 | on VMS and Win32. See the details about those platform specifics |
418 | below. |
864a5fa8 |
419 | |
420 | Dependent libraries can be linked in one of three ways: |
421 | |
422 | =over 2 |
423 | |
424 | =item * For static extensions |
425 | |
426 | by the ld command when the perl binary is linked with the extension |
427 | library. See EXTRALIBS below. |
428 | |
429 | =item * For dynamic extensions |
430 | |
431 | by the ld command when the shared object is built/linked. See |
432 | LDLOADLIBS below. |
433 | |
434 | =item * For dynamic extensions |
435 | |
436 | by the DynaLoader when the shared object is loaded. See BSLOADLIBS |
437 | below. |
438 | |
439 | =back |
440 | |
441 | =head2 EXTRALIBS |
442 | |
443 | List of libraries that need to be linked with when linking a perl |
444 | binary which includes this extension Only those libraries that |
445 | actually exist are included. These are written to a file and used |
446 | when linking perl. |
447 | |
448 | =head2 LDLOADLIBS and LD_RUN_PATH |
449 | |
450 | List of those libraries which can or must be linked into the shared |
451 | library when created using ld. These may be static or dynamic |
452 | libraries. LD_RUN_PATH is a colon separated list of the directories |
453 | in LDLOADLIBS. It is passed as an environment variable to the process |
454 | that links the shared library. |
455 | |
456 | =head2 BSLOADLIBS |
457 | |
458 | List of those libraries that are needed but can be linked in |
459 | dynamically at run time on this platform. SunOS/Solaris does not need |
460 | this because ld records the information (from LDLOADLIBS) into the |
461 | object file. This list is used to create a .bs (bootstrap) file. |
462 | |
463 | =head1 PORTABILITY |
464 | |
465 | This module deals with a lot of system dependencies and has quite a |
466 | few architecture specific B<if>s in the code. |
467 | |
55497cff |
468 | =head2 VMS implementation |
469 | |
470 | The version of ext() which is executed under VMS differs from the |
471 | Unix-OS/2 version in several respects: |
472 | |
473 | =over 2 |
474 | |
475 | =item * |
476 | |
477 | Input library and path specifications are accepted with or without the |
478 | C<-l> and C<-L> prefices used by Unix linkers. If neither prefix is |
479 | present, a token is considered a directory to search if it is in fact |
480 | a directory, and a library to search for otherwise. Authors who wish |
481 | their extensions to be portable to Unix or OS/2 should use the Unix |
482 | prefixes, since the Unix-OS/2 version of ext() requires them. |
483 | |
484 | =item * |
485 | |
486 | Wherever possible, shareable images are preferred to object libraries, |
487 | and object libraries to plain object files. In accordance with VMS |
488 | naming conventions, ext() looks for files named I<lib>shr and I<lib>rtl; |
489 | it also looks for I<lib>lib and libI<lib> to accomodate Unix conventions |
490 | used in some ported software. |
491 | |
492 | =item * |
493 | |
494 | For each library that is found, an appropriate directive for a linker options |
495 | file is generated. The return values are space-separated strings of |
496 | these directives, rather than elements used on the linker command line. |
497 | |
498 | =item * |
499 | |
500 | LDLOADLIBS and EXTRALIBS are always identical under VMS, and BSLOADLIBS |
501 | and LD_RIN_PATH are always empty. |
502 | |
503 | =back |
504 | |
505 | In addition, an attempt is made to recognize several common Unix library |
506 | names, and filter them out or convert them to their VMS equivalents, as |
507 | appropriate. |
508 | |
509 | In general, the VMS version of ext() should properly handle input from |
510 | extensions originally designed for a Unix or VMS environment. If you |
511 | encounter problems, or discover cases where the search could be improved, |
512 | please let us know. |
513 | |
3e3baf6d |
514 | =head2 Win32 implementation |
515 | |
516 | The version of ext() which is executed under Win32 differs from the |
517 | Unix-OS/2 version in several respects: |
518 | |
519 | =over 2 |
520 | |
521 | =item * |
522 | |
523 | Input library and path specifications are accepted with or without the |
524 | C<-l> and C<-L> prefices used by Unix linkers. C<-lfoo> specifies the |
525 | library C<foo.lib> and C<-Ls:ome\dir> specifies a directory to look for |
526 | the libraries that follow. If neither prefix is present, a token is |
527 | considered a directory to search if it is in fact a directory, and a |
528 | library to search for otherwise. The C<$Config{lib_ext}> suffix will |
529 | be appended to any entries that are not directories and don't already |
530 | have the suffix. Authors who wish their extensions to be portable to |
531 | Unix or OS/2 should use the Unix prefixes, since the Unix-OS/2 version |
532 | of ext() requires them. |
533 | |
534 | =item * |
535 | |
536 | Entries cannot be plain object files, as many Win32 compilers will |
537 | not handle object files in the place of libraries. |
538 | |
539 | =item * |
540 | |
541 | If C<$potential_libs> is empty, the return value will be empty. |
542 | Otherwise, the libraries specified by C<$Config{libs}> (see Config.pm) |
543 | will be appended to the list of C<$potential_libs>. The libraries |
544 | will be searched for in the directories specified in C<$potential_libs> |
545 | as well as in C<$Config{libpth}>. For each library that is found, a |
546 | space-separated list of fully qualified library pathnames is generated. |
547 | You may specify an entry that matches C</:nodefault/i> in |
548 | C<$potential_libs> to disable the appending of default libraries |
549 | found in C<$Config{libs}> (this should be only needed very rarely). |
550 | |
551 | =item * |
552 | |
553 | The libraries specified may be a mixture of static libraries and |
554 | import libraries (to link with DLLs). Since both kinds are used |
555 | pretty transparently on the win32 platform, we do not attempt to |
556 | distinguish between them. |
557 | |
558 | =item * |
559 | |
560 | LDLOADLIBS and EXTRALIBS are always identical under Win32, and BSLOADLIBS |
561 | and LD_RUN_PATH are always empty (this may change in future). |
562 | |
563 | =back |
564 | |
565 | |
864a5fa8 |
566 | =head1 SEE ALSO |
567 | |
568 | L<ExtUtils::MakeMaker> |
569 | |
570 | =cut |
571 | |