The <LANG>_VISIBILITY_PRESET and VISIBILITY_INLINES_HIDDEN were first
merged in commit v2.8.12~322 (Merge topic 'VISIBILITY_PRESET-property',
2013-06-05) but worked only for shared libraries and executables with
exports. Prior to commit v3.0.0-rc1~581^2 (GenerateExportHeader:
Deprecate add_compiler_export_flags function., 2013-09-02) the
add_compiler_export_flags function was used to add visibility flags to
all targets.
The visibility flags are useful for sources in all target types because
they may be later linked into shared libraries or executables with
exports. Introduce policy CMP0063 to enable them for all target types
while preserving compatibility with existing projects that do not expect
this.
Enable languages only in the individual test case. Enable the test
everywhere except Visual Studio generators (which do not implement the
properties) and just set fake flags as needed to activate relevant code
paths. Drop unneeded CMAKE_SUPPRESS_REGENERATION which seems to have
been copied from an unrelated test when this test was created.
Set the minimum required version of CMake high enough to avoid the
warning for CMAKE_LEGACY_CYGWIN_WIN32. The warning appears on stderr
and breaks the expected output matching.
This is initialized by CMAKE_<LANG>_VISIBILITY_PRESET. The target
property is used as the operand to the -fvisibility= compile option
with GNU compilers and clang.
Stephen Kelly
Brad King