in reply to [XS on Win32] How to have the extension's dll export its symbols.

Two ways I know of:

  1. Add the functions to be exported to the .def file.
  2. Add __declspec(dllexport) inline with each exported function definition.

Update: See for pros and cons

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Re^2: [XS on Win32] How to have the extension's dll export its symbols.
by syphilis (Archbishop) on Mar 05, 2008 at 12:37 UTC
    As regards point 1 :
    The def file is auto-generated during the 'make' process - which is 'dmake', in my case. How does one influence the contents of the def file that is created by that automated procedure ?

    As regards point 2 :
    I changed Foo.xs so that it now has: 
    #include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

int __declspec(dllexport) foo(int x, int y) {
    return x + y;
}

MODULE = Foo    PACKAGE = Foo    

PROTOTYPES: DISABLE


int
foo (x, y)
    int    x
    int    y

    [download]
    But, according to dumpbin /exports, 'Foo.dll' still exports only '_boot_Foo' and 'boot_Foo'.

    I'm using the MinGW compiler - don't know if that has any bearing on the matter ... apologies if I'm being dense.

    Cheers,
    Rob
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      I'm using the MinGW compiler ...

      If you follow the link I belatedly added to my response you'll see that dllexport is an MS specific extension. Presumably the __declspec() bit is a part of some standard otherwise you'd be getting an error.

      Whether MinGW supports a similar extension I don't know. They can build .sos an .dlls so must have encountered similar problems.

      1. How does one influence the contents of the def file that is created by that automated procedure ?

        I looked that up a while ago. There is mention in the pod for E::MM of a coniguration attribute DL_FUNCS which seems to be something to do with it.

      2. I changed Foo.xs so that it now has:

        See above:)

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
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        There is mention in the pod for E::MM of a coniguration attribute DL_FUNCS which seems to be something to do with it

        Yes - that's probberly the way to go. I tried inserting 'DL_FUNCS' => {'Foo' => ['boot_Foo', 'foo']}, into WriteMakefile() of the Makefile.PL. Having done that, dumpbin reports that Foo.dll exports XS_Foo_foo, _XS_Foo_foo, boot_Foo and _boot_Foo. I'm wanting to see that foo, _foo, boot_Foo, and _boot_Foo are exported. (I've just got to work out how to remove that "XS_Foo_" prefix.)

        Cheers,
        Rob
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