Now that the autodifferentiation support is being upstreamed, add an
option to enable building the TensorFlow swift-apis package optionally.
This enables easier development cycles for the engineers working on it.
This migrates the playground support out of the build-script-impl and
into the python based build system. This makes it build more similarly
to the Swift Package Manager and SourceKit-LSP. More importantly, it
reduces the dependency on build-script-impl.
The build scripts assume Android cross-compilation using the NDK, so avoid
that configuration if building on an Android host. Fix or disable some tests,
and don't install a glibc.modulemap without a native sysroot prefix.
This option configures the build directories without building any
targets. Splitting configuration from build allows for the decoupling
of build products. This decoupling is essential for the enlightened
way of developing Swift where the build-script is never actually used
to build anything, and build products can be independently
configured. When fully supported, this avoids many unnecessary
full/clean rebuilds and enables debugging by mixing-and-matching
configurations and rebuilding only select products after a change.
Sadly, the option has degraded, and a recent commit rendered it fully broken:
commit 34848e6026
Author: Alex Langford <apl@fb.com>
Date: Wed Jan 22 19:27:44 2020
[build] Unify logic to skip building projects in build-script-impl
The breaking commit was itself a reasonable cleanup. The underlying
problem was the original --skip-build was implemented using hacks that
conflated configuration with build.
This fix reinstates a reasonable situation:
--skip-build has no effect on configuration, as documented. It merely
skips building the targets. This is how it must behave to work as
intended.
--skip-build-{product} and its inverse --build-{product} controls
which products will be configured. These options are in heavy use
throughout the scripts, so changing the name (e.g. to --skip-config)
would be disruptive and of questionable benefit.
None of this changes the fact that any required build logic that
people have dumped into build-script-impl still effectively breaks the
enlightened way of building Swift, particularly when building
toolchain components.
Add support for testing with macCatalyst to lit.cfg and the test CMake.
This adds lit test features for whether the standard library and runtime was
built with macCatalyst support:
REQUIRES: maccatalyst_support
The test suite can also be run in two modes: one where the macOS tests
are run as usual (against a zippered standard library, runtime, and overlays)
and another where iOS tests are compiled with the macCatalyst target
triple and executed as macCatalyst processes.
The iOS tests for macCatalyst can be run by passing `--maccatalyst-ios-tests`
to build-script. There are new lit test features to enable a test to specify
whether it supports that environment:
REQUIRES: OS=maccatalyst
UNSUPPORTED: OS=macCatalyst
This commit adds initial build system support for macCatalyst,
an Apple technology that enables code targeting iOS
to be recompiled so that it can be executed on macOS while still using
iOS APIs. This is the first in a series of commits building out support for
macCatalyst in the compiler, runtime, standard library, and overlays. Swift
for macCatalyst represents the work of multiple people, including
Devin Coughlin, Ross Bayer, and Brent Royal-Gordon.
Under macCatalyst, compiler-provided shared libraries (including overlays)
are built as one of four kinds (or "flavors") of libraries,
each with different install names and Mach-O load commands. This commit
adds the build system infrastructure to produce these different
library flavors.
**macOS-like Libraries**
A "macOS-like" library (such as the GLKit overlay) is a plain-old macOS library
that can only be loaded into regular macOS processes. It has a macOS slice with
a single load command allowing it to be loaded into normal macOS processes.
**iOS-like Libraries**
An "iOS-like" library, such as the UIKit overlay, is a library with a
macOS slice but with a load command that only allows it be loaded into
macCatalyst processes. iOS-like libraries are produced by passing a new
target tuple to the compiler:
swiftc ... -target x86_64-apple-ios13.0-macabi ...
Here 'ios' (and an iOS version number) is used for OS portion
of the triple, but the 'macabi' environment tells the compiler
that the library is intended for macCatalyst.
**Zippered Libraries**
A "zippered" library can be loaded into either a macCatalyst process or
a standard macOS process. Since macCatalyst does not introduce a new Mach-O
slice, the same code is shared between both processes. Zippered libraries
are usually relatively low level and with an API surface that is similar
between macOS and iOS (for example, both the Foundation overlay and the Swift
Standard Library/Runtime itself are zippered).
Zippered libraries are created by passing both the usual `-target`
flag to the compiler and an additional `-target-variant` flag:
swiftc ... -target x86_64-apple-macos10.15 \
-target-variant x86_64-apple-ios13.0-macabi
Just like the -target flag, -target-variant takes a target tuple.
This tells the compiler to compile the library for the -target tuple but
to add an extra load command, allowing the library to be loaded into processes
of the -target-variant flavor as well.
While a single zippered library and slice is shared between macOS and
macCatalyst, zippered libraries require two separate .swiftinterface/.swiftmodule
files, one for macOS and one for macCatalyst. When a macOS or macCatalyst client
imports the library, it will use module file for its flavor to determine what
symbols are present. This enables a zippered library to expose a subset of its
target APIs to its target-variant.
**Unzippered-Twin Libraries**
"Unzippered Twins" are pairs of libraries with the same name but different
contents and install locations, one for use from macOS processes and one for
use from macCatalyst processes. Unzippered twins are usually libraries that
depend on AppKit on macOS and UIKit on iOS (for example, the MapKit overlay)
and so do not share a common implementation between macOS and macCatalyst.
The macCatalyst version of an unzippered twin is installed in a parallel
directory hierarchy rooted at /System/iOSSupport/. So, for example, while macOS
and zippered Swift overlays are installed in /usr/lib/swift/, iOS-like and
the macCatalyst side of unzippered twins are installed in
/System/iOSSupport/usr/lib/swift. When building for macCatalyst, the build system
passes additional search paths so that the macCatalyst version of libraries is
found before macOS versions.
The add_swift_target_library() funciton now take an
optional MACCATALYST_BUILD_FLAVOR, which enables swift libraries to indicate
which flavor of library they are.
The Version object used __slots__ instead of __dict__, so it was not serializable. Update JSONDumper to stringify objects if vars() won’t work.
This change does not update any tests because build-script does not currently have a way to write full-script integration tests.
Previously, you were to check if a build/test/install is necessary in
the builds/test/install method which is easy to miss. This gives the
check more visibility.
- For Linux only, if the checked out CMake repository is a newer version
than the installed CMake version or CMake is not installed, build and
use CMake from source.
- This does not affect macOS build or set any minimum required CMake
version in CMakeLists.txt
- For Linux only, if the checked out CMake repository is a newer version
than the installed CMake version or CMake is not installed, build and
use CMake from source.
- This does not affect macOS build or set any minimum required CMake
version in CMakeLists.txt
