Store in new platform variables
CMAKE_${lang}_COMPILE_OPTIONS_PIC
CMAKE_${lang}_COMPILE_OPTIONS_PIE
flags for position independent code generation.
In almost all cases, this means duplication of the
CMAKE_SHARED_LIBRARY_${lang}_FLAGS for the _PIC case and using the
assumed pie equivalent for the _PIE case. Note that the GNU compiler
has supported -fPIE since 3.4 and that there is no -fPIC on GNU for
Windows or Cygwin.
There is a possibility that the _PIE variables are not correct.
However, as there is no backwards compatibility to be concerned about
(as the POSITION_INDEPENDENT_CODE property is not used anywhere yet),
the current state suffices.
Several platform-wide linker flag variables are defined in
Modules/Platform/<os>.cmake files for C and then copied by the
Modules/CMake<lang>Information.cmake file for each language.
We now use this approach for the variables
CMAKE_EXE_EXPORTS_${lang}_FLAG
CMAKE_SHARED_LIBRARY_SONAME_${lang}_FLAG
CMAKE_SHARED_LIBRARY_CREATE_${lang}_FLAGS
to avoid duplication for multiple languages in each platform file.
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.
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
Stephen Kelly
Brad King
Alexander Neundorf
Bill Hoffman