ENH: Added -D(library_name)_EXPORTS to build rules for sources that are going to be linked into a shared library. This allows dllexport setup for DLL building on cygwin. It may also come in handy in unix in the future. This corresponds to the same definition added by the dll dsp template in windows.

Source/cmUnixMakefileGenerator.cxx

@@ -1173,6 +1173,11 @@ void cmUnixMakefileGenerator::OutputSourceObjectBuildRules(std::ostream& fout)
       target != targets.end(); ++target)
     {
     bool shared = (target->second.GetType() == cmTarget::SHARED_LIBRARY);
+    std::string exportsDef = "";
+    if(shared)
+      {
+      exportsDef = "-D"+target->first+"_EXPORTS ";
+      }
     // Iterate over every source for this target.
     const std::vector<cmSourceFile>& sources = target->second.GetSourceFiles();
     for(std::vector<cmSourceFile>::const_iterator source = sources.begin(); 
@@ -1217,12 +1222,12 @@ void cmUnixMakefileGenerator::OutputSourceObjectBuildRules(std::ostream& fout)
           std::string ext = source->GetSourceExtension();
           if ( ext == "cxx" || ext == "cc" || ext == "cpp" || ext == "C" )
             {
-            fout << "\t${CMAKE_CXX_COMPILER} ${CMAKE_CXXFLAGS} "
+            fout << "\t${CMAKE_CXX_COMPILER} ${CMAKE_CXXFLAGS} " << exportsDef.c_str()
                  << (shared? "${CMAKE_SHLIB_CFLAGS} ":"") << "${INCLUDE_FLAGS} -c $< -o $@\n\n";
             }
           else if ( ext == "c" )
             {
-            fout << "\t${CMAKE_C_COMPILER} ${CMAKE_CFLAGS} "
+            fout << "\t${CMAKE_C_COMPILER} ${CMAKE_CFLAGS} " << exportsDef.c_str()
                  << (shared? "${CMAKE_SHLIB_CFLAGS} ":"") << "${INCLUDE_FLAGS} -c $< -o $@\n\n";
             }
           }