Handle the case where the user changes the DEFINE_SYMBOL property.

This eases porting of KDE code.

Tests/Module/GenerateExportHeader/CMakeLists.txt

@@ -107,6 +107,8 @@ macro_add_test_library(libstatic)
 add_subdirectory(lib_shared_and_static)
 add_subdirectory(lib_shared_and_statictest)
 
+add_subdirectory(override_symbol)
+
 if (CMAKE_COMPILER_IS_GNUCXX)
   # We deliberately call deprecated methods, and test for that elsewhere.
   # No need to clutter the test output with warnings.

Tests/Module/GenerateExportHeader/override_symbol/CMakeLists.txt

@@ -0,0 +1,11 @@
+project(override_symbol)
+
+add_library(somelib SHARED someclass.cpp)
+
+set_target_properties(somelib PROPERTIES DEFINE_SYMBOL SOMELIB_MAKEDLL)
+
+generate_export_header(somelib)
+
+add_executable(consumer main.cpp)
+
+target_link_libraries(consumer somelib)

Tests/Module/GenerateExportHeader/override_symbol/main.cpp

@@ -0,0 +1,9 @@
+
+#include "someclass.h"
+
+int main(int, char**)
+{
+  SomeClass sc;
+  sc.someMethod();
+  return 0;
+}

Tests/Module/GenerateExportHeader/override_symbol/someclass.cpp

@@ -0,0 +1,7 @@
+
+#include "someclass.h"
+
+void SomeClass::someMethod() const
+{
+
+}

Tests/Module/GenerateExportHeader/override_symbol/someclass.h

@@ -0,0 +1,8 @@
+
+#include "somelib_export.h"
+
+class SOMELIB_EXPORT SomeClass
+{
+public:
+  void someMethod() const;
+};