The Windows SDK provides headers which have incorrect cases. The
incorrect cases are in the SDK headers as well. On case sensitive file
systems this causes build issues due to the incorrect name. Use the
clang VFS overlay to avoid the need for providing copies to the expected
cases. This improves the cross-compilation on Linux to Windows.
When passing the linker search path options to the driver, ensure that
we quote the argument. We would previously incorrectly split the
arguments that were passed to the driver if there were spaces. This
would manifest as link failures on Linux when cross-compiling to
Windows.
The Windows ARM SDK is incomplete. However, the headers are complete
enough to support building the runtime. Add the necessary definitions
to permit the stdlib to be built.
Rather than use the `INCLUDE` and `LIB` environment variables to build
the Windows code, use the `UniversalCRTSdkDir`, `UCRTVersion`, and
`VCToolsInstallDir` variables. Using these we can compute the right set
of include directories and library search paths for the various
architectures. This will enable us to build multiple variants of the
Windows stdlib at the same time.
Additionally, rather than relying on the magic environment variables to
be processed by the driver, pass them explicitly to the driver through
the build system. This also is needed to allow parallel builds of
various architecture variants of the stdlib on Windows.
When building for Windows, when using `offsetof` in a C++ context, we
would use a `reinterpret_cast`, which is not permissible in the context
of a `constexpr` statement which we do use. Use a CRT specific macro to
use the `__builtin_offsetof` version of the implementation. Repairs the
Windows stdlib build with the new include path handling.
The file system layout on exherbo is different from most other Linux
distributions. Add an additional ignored case for the include paths for
when cross-compiling the stdlib to additional targets.
Introduce a new function `add_swift_tool_symlink`. Use this instead of the
`add_llvm_tool_symlink` and `install_in_swift_component`. This mimics the
behaviour in clang as well as the general pattern of renaming the functions from
the LLVM build infrastructure.
Adds the runtime implementation for copy-on-write existentials. This support is
enabled if SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS is defined. Focus is on
correctness -- not performance yet.
Don't use allocate/deallocate/projectBuffer witnesses for globals in cow
existential mode.
Use SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS configuration to set the default for
SILOptions.
This includes an IRGen fix to use the right projection in
emitMetatypeOfOpaqueExistential if SWIFT_RUNTIME_ENABLE_COW_EXISTENTIALS is set.
Use unknownRetain instead of native retain in dynamicCastToExistential.
The std::atomic implementation in MSVC broke ABI compatibility across a
minor update (VS2015U2). Permit the ABI breaking change for the use in
the runtime.
* Omit leaf frame pointers on i686 architectures
This is x86. See the root CMakeLists.txt file
```
elseif("${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "x86")
set(SWIFT_HOST_VARIANT_ARCH_default "i686")
```
* Use the correct flags to omit leaf frame pointers with clang-cl and MSVC
* Don't omit leaf frame pointers on 64 bit architectures
