Commit for CMake and build scripts to recognize OpenBSD. To keep this
commit relatively short, this just deals with the rather simple and
uncontroversial changes to the build system.
Note that OpenBSD calls "x86_64" as "amd64", Since the Swift stdlib will
be put in a subdirectory named after ARCH, to ensure the standard
library is properly found later, we use the native architecture name for
OpenBSD in the build system rather than trying to deal with the
difference the other way around.
- Get rid of the singular (*_INCLUDE_DIR and *_LIBRARY) variables and
standardize on the plural ones, since that's also what's used by
CMake's FindICU module (which was added in 3.7).
- Use PKG_CONFIG_FOUND instead of PKGCONFIG_FOUND, since that's what's
documented in CMake's FindPkgConfig module. (The latter will be set by
the find_package call, so it's not incorrect, but it's clearer to use
the documented variable.)
- Search for the headers and libraries even if pkg-config can't find the
module, since e.g. we might have ICU somewhere in our CMake search
path but might not have the pkg-config module for it. We're only using
the pkg-config results as search hints anyway. (This might result in
an empty HINTS argument to find_path and find_library, but CMake seems
to handle that fine.) *This should be the only functional change.*
- Remove ICU_${MODULE}_DEFINITIONS, since it's never used anywhere.
- Don't add the *_INCLUDEDIR and *_LIBDIR variables to the hints, since
they should be the same as the corresponding *_INCLUDE_DIRS and
*_LIBRARY_DIRS variables (since we're only searching for a single
module).
The only intended functional change, as mentioned above, is that we can
now successfully find ICU if its include and library directories are in
the CMake search path but its pkg-config module isn't, which might be
the case in certain cross-compilation or hermetic build scenarios. (It's
compounded by CMake only looking for pkg-config modules in
CMAKE_PREFIX_PATH and not CMAKE_SYSTEM_PREFIX_PATH, which I asked about
in https://cmake.org/pipermail/cmake/2018-August/068109.html).
This is needed to support cross-compilation on targets which do not
support FAT binaries (i.e. non-MachO targets). The primary user of this
functionality right now is Windows, but this support is needed for Linux
and android as well.
If you don't have PkgConfig, you'll need to pass the following to CMake:
```
-DICU_UC_INCLUDE_DIRS="%swift_source_dir%/icu/include"^
-DICU_UC_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
-DICU_I18N_INCLUDE_DIRS="%swift_source_dir%/icu/include"^
-DICU_I18N_LIBRARY_DIRS="%swift_source_dir%/icu/lib64"^
-DICU_UC_LIB_NAME="icuuc"^
-DICU_I18N_LIB_NAME="icuin"
```
icu
Fixes the Android build, and makes some adjustments for Android NDK r13.
* Fix FindICU.cmake to properly set the `SWIFT_${sdk}_ICU_UC` and
`SWIFT_${sdk}_ICU_I18N` values. These were not properly set because
"uc" and "i18n" were lowercase.
* Adapt `add_swift_library` to parse `ICU_UC` and `ICU_I18N` for
private link libraries and use the proper `SWIFT_${sdk}_ICU_*` values.
* NDK r13 removes a subdirectory from the llvm-libc++ includes path.
Adapt to this change, and add a FIXME to address this issue before it
may break again.
* Update the documentation to point to a new libicu download for NDK 13.
This allows us to cross-compile the standard library to foreign targets on a
single host. The ICU dependencies can be specified on the command line on a
per-target basis. If one is not specified, we fall back to the default search
path and use that for the other targets.
Special thanks to Dimitri Gribenko for the various hints in getting this wired
up.
This adds an Android target for the stdlib. It is also the first
example of cross-compiling outside of Darwin.
Mailing list discussions:
1. https://lists.swift.org/pipermail/swift-dev/Week-of-Mon-20151207/000171.html
2. https://lists.swift.org/pipermail/swift-dev/Week-of-Mon-20151214/000492.html
The Android variant of Swift may be built using the following `build-script`
invocation:
```
$ utils/build-script \
-R \ # Build in ReleaseAssert mode.
--android \ # Build for Android.
--android-ndk ~/android-ndk-r10e \ # Path to an Android NDK.
--android-ndk-version 21 \
--android-icu-uc ~/libicu-android/armeabi-v7a/libicuuc.so \
--android-icu-uc-include ~/libicu-android/armeabi-v7a/icu/source/common \
--android-icu-i18n ~/libicu-android/armeabi-v7a/libicui18n.so \
--android-icu-i18n-include ~/libicu-android/armeabi-v7a/icu/source/i18n/
```
Android builds have the following dependencies, as can be seen in
the build script invocation:
1. An Android NDK of version 21 or greater, available to download
here: http://developer.android.com/ndk/downloads/index.html.
2. A libicu compatible with android-armv7.
