Commit dac78148 (...makes the mingw cross compiler work out of the
box..., 2007-08-02) added to CMAKE_SYSTEM_PROGRAM_PATH and
CMAKE_SYSTEM_LIBRARY_PATH paths like "/bin" and "/lib" with no Windows
drive letter so that cross-compiling to Windows from Linux would search
these paths under CMAKE_FIND_ROOT_PATH. Later commit 2a782880 (...use
CMAKE_SYSTEM_PREFIX_PATH when possible, 2008-01-16) generalized this
approach by instead adding "/" to CMAKE_SYSTEM_PREFIX_PATH.
Both commits assumed that the paths would never match anything on
Windows hosts without a drive letter. However, Windows evaluates these
paths relative to the current working drive letter so find_* commands
may report paths like "/lib/..." when paths like "c:/lib/..." exist on
what happens to be current drive. Such drive-less paths are not
reliable when the working drive changes, so we should not use them.
Fix WindowsPaths.cmake to add '/' to CMAKE_SYSTEM_PREFIX_PATH only when
cross-compiling to Windows from a non-Windows host. This will avoid
searching and finding local paths without a drive letter on Windows.
Block multiple inclusion because "Modules/CMakeCInformation.cmake"
includes "Platform/${CMAKE_SYSTEM_NAME}" even though the generic
module "CMakeSystemSpecificInformation.cmake" already included it.
The extra inclusion is a work-around to address issue #4772 without
intrusive platform file changes. Once those changes are made the
work-around and these include blockers can be removed. See issue #9656.
On 64-bit Windows there may be two Program Files folders, one for 32-bit
binaries and one for 64-bit binaries. When we compute
CMAKE_SYSTEM_PREFIX_PATH we should put both folders in the path.
-add /usr/openwin/include and /usr/openwin/lib to the default search paths
-add /${CMAKE_INSTALL_PREFIX}/(lib|bin|include) to the default cmake search
paths -> this should help users who install stuff in their home
Alex