Fix cygwin builds #121

Cygwin claims to be POSIX but only implementes part of
the dl_open interface.

For this usage, we revert to win32 interface when building on
Cygwin.

CMakeLists.txt

@@ -147,7 +147,7 @@ endif()
 
 # limitations in MinGW require us to make an optimized build
 # for the sake of object sizes or something
-if(MINGW)
+if(MINGW OR CYGWIN)
   add_definitions(-O3)
 endif()
 

include/chaiscript/chaiscript_defines.hpp

@@ -12,7 +12,7 @@
 #define CHAISCRIPT_HAS_DECLSPEC
 #endif
 
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__CYGWIN__)
 #define CHAISCRIPT_WINDOWS
 #endif
 

include/chaiscript/language/chaiscript_engine.hpp

@@ -34,7 +34,7 @@
 #include <unistd.h>
 #endif
 
-#ifdef _POSIX_VERSION
+#if defined(_POSIX_VERSION) && !defined(__CYGWIN__) 
 #include <dlfcn.h>
 #else
 #ifdef CHAISCRIPT_WINDOWS
@@ -69,7 +69,7 @@ namespace chaiscript
 
   namespace detail
   {
-#ifdef _POSIX_VERSION
+#if defined(_POSIX_VERSION) && !defined(__CYGWIN__) 
     struct Loadable_Module
     {
       struct DLModule
@@ -438,8 +438,7 @@ namespace chaiscript
         m_usepaths.push_back("");
       }
 
-
-#ifdef _POSIX_VERSION
+#if defined(_POSIX_VERSION) && !defined(__CYGWIN__) 
       // If on Unix, add the path of the current executable to the module search path
       // as windows would do
 
@@ -704,6 +703,7 @@ namespace chaiscript
 
       std::vector<std::string> prefixes;
       prefixes.push_back("lib");
+      prefixes.push_back("cyg");
       prefixes.push_back("");
 
       std::vector<std::string> postfixes;