cmake: enable WINDOWS_EXPORT_ALL_SYMBOLS

Enable the [`WINDOWS_EXPORT_ALL_SYMBOLS` CMake property][1],
which automatically exports all symbols into the `.dll` file.

This feature is available since [CMake 3.4][2], which is fine,
since the minimum version of CMake CMocka supports is CMake 3.5.

It is a bit slower, but it does mean that we no longer need to
manually create a `.def` file, as CMake will automatically create one
for us.

[1]: https://cmake.org/cmake/help/latest/prop_tgt/WINDOWS_EXPORT_ALL_SYMBOLS.html
[2]: https://www.kitware.com//create-dlls-on-windows-without-declspec-using-new-cmake-export-all-feature/

Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

src/CMakeLists.txt

@@ -12,13 +12,6 @@ set(cmocka_SRCS
     cmocka.c
 )
 
-if (WIN32)
-    set(cmocka_SRCS
-        ${cmocka_SRCS}
-        cmocka.def
-    )
-endif (WIN32)
-
 add_library(cmocka ${cmocka_SRCS})
 
 target_include_directories(cmocka
@@ -59,6 +52,8 @@ set_target_properties(cmocka PROPERTIES
                       C_STANDARD_REQUIRED   ON
                       # cmocka uses POSIX-2008 C extensions
                       C_EXTENSIONS          ON
+                      # automatically export all global objects into DLL on Windows
+                      WINDOWS_EXPORT_ALL_SYMBOLS ON
 )
 
 add_library(cmocka::cmocka ALIAS cmocka)

src/cmocka.def

@@ -1,62 +0,0 @@
-LIBRARY cmocka
-EXPORTS
-    _assert_double_equal
-    _assert_double_not_equal
-    _assert_float_equal
-    _assert_float_not_equal
-    _assert_int_equal
-    _assert_int_in_range
-    _assert_int_in_set
-    _assert_int_not_equal
-    _assert_int_not_in_range
-    _assert_int_not_in_set
-    _assert_memory_equal
-    _assert_memory_not_equal
-    _assert_not_in_set
-    _assert_return_code
-    _assert_string_equal
-    _assert_string_not_equal
-    _assert_true
-    _assert_uint_equal
-    _assert_uint_in_range
-    _assert_uint_in_set
-    _assert_uint_not_equal
-    _assert_uint_not_in_range
-    _assert_uint_not_in_set
-    _check_expected
-    _cmocka_run_group_tests
-    _expect_any
-    _expect_check
-    _expect_function_call
-    _expect_in_range
-    _expect_in_set
-    _expect_memory
-    _expect_not_in_range
-    _expect_not_in_set
-    _expect_not_memory
-    _expect_not_string
-    _expect_not_value
-    _expect_string
-    _expect_value
-    _fail
-    _function_called
-    _mock
-    _skip
-    _stop
-    _test_calloc
-    _test_free
-    _test_malloc
-    _test_realloc
-    _will_return
-    cmocka_print_error
-    cmocka_set_message_output
-    cmocka_set_test_filter
-    cmocka_set_skip_filter
-    global_expect_assert_env DATA
-    global_expecting_assert DATA
-    global_last_failed_assert DATA
-    mock_assert
-    print_error
-    print_message
-    vprint_error
-    vprint_message