cmake: Cygwin dllexport/dllimport

[Yaakov Selkowitz]

Tony,

Could you please include the attached patch (created wrt 3.2.3) with the
next release of cmake?  It is required for building KF5.

TIA,

Yaakov



--- origsrc/cmake-3.2.3/Modules/GenerateExportHeader.cmake	2015-06-01 10:56:08.000000000 -0500
+++ src/cmake-3.2.3/Modules/GenerateExportHeader.cmake	2015-07-21 17:03:05.027228100 -0500
@@ -268,7 +268,7 @@ macro(_DO_SET_MACRO_VALUES TARGET_LIBRAR
   get_property(type TARGET ${TARGET_LIBRARY} PROPERTY TYPE)
 
   if(NOT ${type} STREQUAL "STATIC_LIBRARY")
-    if(WIN32)
+    if(WIN32 OR CYGWIN)
       set(DEFINE_EXPORT "__declspec(dllexport)")
       set(DEFINE_IMPORT "__declspec(dllimport)")
     elseif(COMPILER_HAS_HIDDEN_VISIBILITY AND USE_COMPILER_HIDDEN_VISIBILITY)