While Cygwin supports linking directly to .dll files, the behavior is
now discouraged. All Cygwin packages now provide import libraries of
the form lib*.dll.a and CMake has built the import libraries for years.
We believe it is now safe to stop explicitly searching for .dll files
because their import libraries will always be available when the
corresponding header files are available. Users can always set
find_library cache entries to point at a .dll file by hand if they
really must use one.
Change based on patch from issue #10122.
This moves GNU compiler flags into new-style modules
Compiler/GNU-<lang>.cmake
Platform/<os>-GNU-<lang>.cmake
We use language-independent helper modules
Compiler/GNU.cmake
Platform/<os>-GNU.cmake
to define macros consolidating the information.
This enables the --enable-auto-import linker flag on Cygwin when linking
executables. It works with the old gcc 3.x compiler and is necessary
for the new gcc 4.x compiler. See issue #9071.
cmMakefile.cxx, but now in the platform files and are now valid for the
target platform, not the host platform.
New variables CMAKE_HOST_WIN32, CMAKE_HOST_UNIX, CMAKE_HOST_APPLE and
CMAKE_HOST_CYGWIN have been added in cmMakefile.cxx (...and have now to be
used in all cmake files which are executed before
CMakeSystemSpecificInformation.cmake is loaded). For compatibility the old
set is set to the new one in CMakeDetermineSystem.cmake and reset before the
system platform files are loaded, so custom language or compiler modules
which use these should still work.
Alex