New in version 3.4.

This property is implemented only for MS-compatible tools on Windows.

Enable this boolean property to automatically create a module definition (.def) file with all global symbols found in the input .obj files for a SHARED library (or executable with ENABLE_EXPORTS) on Windows. The module definition file will be passed to the linker causing all symbols to be exported from the .dll. For global data symbols, __declspec(dllimport) must still be used when compiling against the code in the .dll. All other function symbols will be automatically exported and imported by callers. This simplifies porting projects to Windows by reducing the need for explicit dllexport markup, even in C++ classes.

When this property is enabled, zero or more .def files may also be specified as source files of the target. The exports named by these files will be merged with those detected from the object files to generate a single module definition file to be passed to the linker. This can be used to export symbols from a .dll that are not in any of its object files but are added by the linker from dependencies (e.g. msvcrt.lib).

This property is initialized by the value of the CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS variable if it is set when a target is created.