Problem: mingw static/shared builds have different preprocessor defines

Solution: remove objects optimisation in library build (similar to #2860)
and set PUBLIC compile definitions on all static builds instead of MSVC
only.

CMakeLists.txt

@@ -911,20 +911,27 @@ if (MSVC)
  DEBUG_POSTFIX "${MSVC_TOOLSET}-mt-sgd-${ZMQ_VERSION_MAJOR}_${ZMQ_VERSION_MINOR}_${ZMQ_VERSION_PATCH}"
  COMPILE_FLAGS "/DZMQ_STATIC"
  OUTPUT_NAME "libzmq")
-
- target_compile_definitions(libzmq-static
- PUBLIC ZMQ_STATIC
- )
-
  endif()
 else ()
  # avoid building everything twice for shared + static
  # only on *nix, as Windows needs different preprocessor defines in static builds
- add_library (objects OBJECT ${sources})
- set_property(TARGET objects PROPERTY POSITION_INDEPENDENT_CODE ON)
+ if (NOT MINGW)
+ add_library (objects OBJECT ${sources})
+ set_property(TARGET objects PROPERTY POSITION_INDEPENDENT_CODE ON)
+ target_include_directories (objects
+ PUBLIC
+ $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+ $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
+ $<INSTALL_INTERFACE:include>
+ )
+ endif ()
 
  if (BUILD_SHARED)
- add_library (libzmq SHARED $<TARGET_OBJECTS:objects> ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ if (MINGW)
+ add_library (libzmq SHARED ${sources} ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ else ()
+ add_library (libzmq SHARED $<TARGET_OBJECTS:objects> ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ endif ()
  # NOTE: the SOVERSION and VERSION MUST be the same as the one generated by libtool! It is NOT the same as the version of the package.
  set_target_properties (libzmq PROPERTIES
  COMPILE_DEFINITIONS "DLL_EXPORT"
@@ -949,19 +956,22 @@ else ()
  endif()
 
  if (BUILD_STATIC)
- add_library (libzmq-static STATIC $<TARGET_OBJECTS:objects> ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ if (MINGW)
+ add_library (libzmq-static STATIC ${sources} ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ else ()
+ add_library (libzmq-static STATIC $<TARGET_OBJECTS:objects> ${public_headers} ${html-docs} ${readme-docs} ${zmq-pkgconfig} ${CMAKE_CURRENT_BINARY_DIR}/version.rc)
+ endif ()
  set_target_properties (libzmq-static PROPERTIES
  PUBLIC_HEADER "${public_headers}"
- COMPILE_DEFINITIONS "ZMQ_STATIC"
  OUTPUT_NAME "zmq"
  PREFIX "lib")
  endif()
 
- target_include_directories (objects
- PUBLIC
- $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-  $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}>
-  $<INSTALL_INTERFACE:include>
+endif ()
+
+if (BUILD_STATIC)
+ target_compile_definitions(libzmq-static
+ PUBLIC ZMQ_STATIC
  )
 endif ()