Fix test cases/common/125 on Cygwin

test cases/common/125 shared module/meson.build

@@ -5,7 +5,8 @@ l = shared_library('runtime', 'runtime.c')
 # Do NOT link the module with the runtime library. This
 # is a common approach for plugins that are only used
 # with dlopen. Any symbols are resolved dynamically
-# at runtime
+# at runtime.  This requires extra help on Windows, so
+# should be avoided unless really neccessary.
 m = shared_module('mymodule', 'module.c')
 e = executable('prog', 'prog.c', link_with : l, dependencies : dl)
 test('import test', e, args : m)

test cases/common/125 shared module/module.c

@@ -9,14 +9,24 @@
   #endif
 #endif
 
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__CYGWIN__)
 
 #include <stdio.h>
-#include <windows.h>
-#include <tlhelp32.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>
+
 /* 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
@@ -45,6 +55,7 @@ fptr find_any_f (const char *name) {
     CloseHandle (snapshot);
     return f;
 }
+#endif
 
 int DLL_PUBLIC func() {
     fptr f;