Recoving dup tests for VMS
[p5sagit/p5-mst-13.2.git] / ext / DynaLoader / README
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a0d0e21e 1Perl 5 DynaLoader
2
3b35bae3 3See DynaLoader.pm for detailed specification.
a0d0e21e 4
5This module is very similar to the other Perl 5 modules except that
6Configure selects which dl_*.xs file to use.
7
3b35bae3 8After Configure has been run the Makefile.PL will generate a Makefile
a0d0e21e 9which will run xsubpp on a specific dl_*.xs file and write the output
10to DynaLoader.c
11
12After that the processing is the same as any other module.
13
14Note that, to be effective, the DynaLoader module must be _statically_
15linked into perl! Configure should arrange this.
16
17This interface is based on the work and comments of (in no particular
18order): Larry Wall, Robert Sanders, Dean Roehrich, Jeff Okamoto, Anno
19Siegel, Thomas Neumann, Paul Marquess, Charles Bailey and others.
20
21The dl_*.xs files should either be named after the dynamic linking
22operating system interface used if that interface is available on more
23than one type of system, e.g.:
24 dlopen for dlopen()/dlsym() type functions (SunOS, BSD)
25 dld for the GNU dld library functions (linux, ?)
26or else the osname, e.g., hpux, next, vms etc.
27
28Both are determined by Configure and so only those specific names that
29Configure knows/uses will work.
30
31If porting the DynaLoader to a platform that has a core dynamic linking
32interface similar to an existing generic type, e.g., dlopen or dld,
33please try to port the corresponding dl_*.xs file (using #ifdef's if
34required).
35
36Otherwise, or if that proves too messy, create a new dl_*.xs file named
37after your osname. Configure will give preference to a dl_$osname.xs
38file if one exists.
39
40The file dl_dlopen.xs is a reference implementation by Paul Marquess
41which is a good place to start if porting from scratch. For more complex
42platforms take a look at dl_dld.xs. The dlutils.c file holds some
43common definitions that are #included into the dl_*.xs files.
44
3b35bae3 45After the initial implementation of a new DynaLoader dl_*.xs file you
46may need to edit or create ext/MODULE/MODULE.bs files (library bootstrap
47files) to reflect the needs of your platform and linking software.
a0d0e21e 48
3b35bae3 49Refer to DynaLoader.pm, lib/ExtUtils/MakeMaker.pm and any existing
a0d0e21e 50ext/MODULE/MODULE.bs files for more information.
51
52Tim Bunce.
53August 1994