One of Cygwin's goals is to build projects using the POSIX API with no
Windows awareness. Many CMake-built projects have been written to test
for UNIX and WIN32 but not CYGWIN. The preferred behavior under Cygwin
in such projects is to take the UNIX path but not the WIN32 path.
Unfortunately this change is BACKWARDS INCOMPATIBLE for Cygwin-aware
CMake projects! Some projects that previously built under Cygwin and
are Cygwin-aware when they test for WIN32 may now behave differently.
Eventually these projects will need to be updated, but to help users
build them in the meantime we print a warning about the change in
behavior. Furthermore, one may set CMAKE_LEGACY_CYGWIN_WIN32 to request
old behavior during the transition.
Normally we avoid backwards incompatible changes, but we make an
exception in this case for a few reasons:
(1) This behavior is preferred by Cygwin's design goals.
(2) A warning provides a clear path forward for everyone who may see
incompatible behavior, and CMAKE_LEGACY_CYGWIN_WIN32 provides a
compatibility option. The warning and compatibility option both
disappear when the minimum required version of CMake in a project is
sufficiently new, so this issue will simply go away over time as
projects are updated to account for the change.
(3) The fixes required to update projects are fairly insignificant.
Furthermore, the Cygwin distribution has no releases itself so project
versions that predate said fixes tend to be difficult to build anyway.
(4) This change enables many CMake-built projects that did not
previously build under Cygwin to work out-of-the-box. From bug #10122:
"I have built over 120 different source packages with (my patched)
CMake, including most of KDE4, and have found that NOT defining
WIN32 on Cygwin is much more accurate." -- Yaakov Selkowitz
A fully compatible change would require patches on top of these project
releases for Cygwin even though they otherwise need not be aware of it.
(5) Yaakov has been maintaining a fork of CMake with this change for the
Cygwin Ports distribution. It works well in practice. By accepting the
change in upstream CMake we avoid confusion between the versions.
CMake itself builds without WIN32 defined on Cygwin. Simply disable
CMAKE_LEGACY_CYGWIN_WIN32 explicitly in our own CMakeLists.txt file.
The Mac linker defines -headerpad_max_install_names and the GCC
front-end passes this flag through. The PGI compiler does not know
about this flag, so we must use -Wl,-headerpad_max_install_names to pass
it to the linker instead.
Use a combination of response files and the archiver to support long
object file lists that do not fit in the Windows command-line length
limit. This can work only with GCC >= 4 because the MinGW GCC 3.x
front-ends do not support response-file syntax.
Set CMAKE_PLATFORM_REQUIRED_RUNTIME_PATH in the HP-UX platform file to
tell CMake to pass -Wl,+b,/usr/lib no matter whether RPATH is enabled or
not. This corrects the behavior of -Wl,+nodefaultrpath to look in this
default library path as documented.
Include this prefix in CMAKE_SYSTEM_PREFIX_PATH so that it will be used
for all find* commands. Previously only find_library and find_path
would look under /opt/local/lib and /opt/local/include, respectively.
BlueGeneP-base: Internal base shared by static and dynamic files
BlueGeneP-static: Platform file for all-static builds
BlueGeneP-dynamic: Platform file for "default" dynamic builds
Use response files for C and CXX languages with the Intel compiler on
Windows. We already used them for Fortran. This enables creation of
libraries and executables with a very large number of object files.
Tru64's make(1) resolves relative paths in "include" directives with
respect to the includer. This is inconsistent with all other known make
tools. Note that this make tool treats the path literally so we cannot
use our standard FULL path code which escapes spaces. Instead qualify
the paths with $(CMAKE_BINARY_DIR) to avoid the problem.
Commit 82c081ba (Fix rpath-link flag for SunPro C++ on Linux,
2009-07-13) taught CMake to pass '-rpath-link' because SunPro C++ 5.9
does not support '-Wl,'. Now SunPro C++ 5.11 does not recognize the
option without using '-Wl,'. Detect whether to use '-Wl,' based on the
output of "sunCC -flags".
The ENABLE_EXPORTS property exports all symbols from executables on
UNIX-like platforms, typically for use by plugins. Honor this behavior
on Cygwin. See issue #10122.
Map to the platform and compiler information for GNU because the
compilers are command-line compatible for common operations. Later we
can add Clang-specific features as necessary. We honor the preferred
capitalization is "Clang", not the common mis-spelling "CLang".
The expectation of users of the MSVC60, MSVC70, MSVC71, MSVC80, MSVC90
and the new MSVC10 variables is that at most one of them will be set
for any given build tree. This change enforces that expectation for
build trees using Makefile generators. It also fixes the one mismatch
in that expectation to be found in the Visual Studio generator world:
previously, the VS 7.1 generator would set *both* MSVC70 and MSVC71;
now, it only sets MSVC71.
With these changes, user expectations are now met, and the recently
introduced CheckCompilerRelatedVariables test should pass everywhere.
As reported on the mailing list, find_path/file/library/program() basically don't work
at all if CMAKE_FIND_ROOT_PATH is set and searching in the host system directories
is disabled. This patch adds /include, /lib and /bin to the search directories, so they
will be appended to CMAKE_FIND_ROOT_PATH so this will work for the "Generic" platform (embedded
systems without OS)
Alex
Detect the runtime linker's search path and add to the compile time
linker's search path. This is needed because OpenBSD's static linker
does not search for shared library dependencies in the same places as
the runtime linker.
Commit "Modernize GNU compiler info on Windows" (2009-12-02) reorganized
GNU flags on Windows but let -fPIC slip through for compilation of
objects in shared libraries. While this flag is valid on most GNU
compiler platforms we need to suppress it in Windows-GNU.cmake just as
we already do in CYGWIN-GNU.cmake.
In commit "use export all symbols on cygwin" (2003-01-21) we started
passing -Wl,--export-all-symbols when linking shared libraries. Now
cygwin exports all symbols automatically if no symbols are explicitly
exported. When symbols are explicitly exported we want to honor that
narrow interface. Therefore this flag should not be passed.
Change based on patch from issue #10122.
The variable should contain the name of a library needed to link the
symbol equivalent to dlopen. On Cygwin no special library is needed,
and certainly not "gdi32".
Change based on patch from issue #10122.
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.
Commit "Find locally installed software first" made /usr/local the first
prefix searched to be consistent with the Filesystem Hierarchy Standard:
http://www.pathname.com/fhs/
The standard also implies that the root prefix "/" should not have any
package or development files. The "/bin" and "/lib" directories should
have only minimal contents to boot the system. No "/include" ever
exists. This commit re-orders the search path prefix list from
/usr/local
/
/usr
to
/usr/local
/usr
/
to prefer package and development files over low-level system files.
See issue #10136.
On Cygwin /usr/lib == /lib and /usr/bin == /bin. This change also makes
search results report locations as "/usr/..." instead of "/lib/...".
See issue #10122.
The commit "Drop -rdynamic from Linux build rules" removed default use
of the flag on Linux. It was expected to be compatible because any
project using plugins should set ENABLE_EXPORTS on its executables to
export their symbols for use by the plugins in a cross-platform way.
However, it is possible to build without ENABLE_EXPORTS and load plugins
that do not link to any symbols from the executable explicitly. These
plugins may need to see RTTI and other executable symbols needed by the
language implementation. Executables using such plugins were broken by
the change.
If we want to remove the -rdynamic flag in the future we should do so in
a compatible way. At that time we should also remove equivalent flags
on other platforms (like -bexpall on AIX). We will either need a policy
or an explicit API to disable symbol exports on executables.
The primary purpose of the above-mentioned commit was to avoid passing
the -rdynamic flag to compilers on Linux that do not support it. In
this commit we restore the flag but only on GNU and Intel compilers
which are known to support it.
See issue #9985.
Default to "" for CMAKE_OSX_DEPLOYMENT_TARGET if CMAKE_OSX_SYSROOT is set. Also, add new error message to detect the case where there is a deployment target, but no SDK has been set. Fix args to STRING REGEX call so that it works even if _sdk_path variable is empty inside sanity check function.
We remove the shared library compile/link flags "-fPIC" and "-shared"
because they are not provided by all compilers on Linux. This allows us
to drop code from the Linux-XL-*.cmake files that erases the bad flags.
All other supported compilers already provide their correct flags for
Linux in their own platform information files.
We factor flags from Platform/Linux-PGI-Fortran.cmake into language
independent helper modules
Compiler/PGI.cmake
Platform/Linux-PGI.cmake
and invoke the macros from
Compiler/PGI-<lang>.cmake
Platform/Linux-PGI-<lang>.cmake
This enables general support for the PGI compilers.
Brad King
Yaakov Selkowitz
Bill Hoffman
Todd Gamblin
Arjen Verweij
Pino Toscano
David Cole
Alex Neundorf
Chuck Atkins