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#if defined _WIN32 || defined __CYGWIN__
#define DLL_PUBLIC __declspec(dllexport)
#else
#if defined __GNUC__
#define DLL_PUBLIC __attribute__ ((visibility("default")))
#else
#pragma message ("Compiler does not support symbol visibility.")
#define DLL_PUBLIC
#endif
#endif
#if defined(_WIN32) || defined(__CYGWIN__)
#include <stdio.h>
typedef int (*fptr) (void);
#ifdef __CYGWIN__
#include <dlfcn.h>
fptr find_any_f (const char *name) {
return (fptr) dlsym(RTLD_DEFAULT, name);
}
#else /* _WIN32 */
#include <windows.h>
#include <tlhelp32.h>
static wchar_t*
win32_get_last_error (void)
{
wchar_t *msg = NULL;
FormatMessageW (FORMAT_MESSAGE_ALLOCATE_BUFFER
| FORMAT_MESSAGE_IGNORE_INSERTS
| FORMAT_MESSAGE_FROM_SYSTEM,
NULL, GetLastError (), 0,
(LPWSTR) &msg, 0, NULL);
return msg;
}
/* Unlike Linux and OS X, when a library is loaded, all the symbols aren't
* loaded into a single namespace. You must fetch the symbol by iterating over
* all loaded modules. Code for finding the function from any of the loaded
* modules is taken from gmodule.c in glib */
fptr find_any_f (const char *name) {
fptr f;
HANDLE snapshot;
MODULEENTRY32 me32;
snapshot = CreateToolhelp32Snapshot (TH32CS_SNAPMODULE, 0);
if (snapshot == (HANDLE) -1) {
wchar_t *msg = win32_get_last_error();
printf("Could not get snapshot: %S\n", msg);
return 0;
}
me32.dwSize = sizeof (me32);
f = NULL;
if (Module32First (snapshot, &me32)) {
do {
if ((f = (fptr) GetProcAddress (me32.hModule, name)) != NULL)
break;
} while (Module32Next (snapshot, &me32));
}
CloseHandle (snapshot);
return f;
}
#endif
int DLL_PUBLIC func(void) {
fptr f;
f = find_any_f ("func_from_language_runtime");
if (f != NULL)
return f();
printf ("Could not find function\n");
return 1;
}
#else
/*
* Shared modules often have references to symbols that are not defined
* at link time, but which will be provided from deps of the executable that
* dlopens it. We need to make sure that this works, i.e. that we do
* not pass -Wl,--no-undefined when linking modules.
*/
int func_from_language_runtime(void);
int DLL_PUBLIC func(void) {
return func_from_language_runtime();
}
#endif
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