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.
There is currently a great deal of duplication across the
`GenericUnix` and `Windows` toolchains. The Android port will
add even more duplication.
To mitigate this, have `Windows` inherit from `GenericUnix`, and
have them share most of their implementation.
In addition, rename `Windows` to `Cygwin` (it would be pretty strange
to have a `Windows` toolchain inherit from something named `*Unix`).
That's DYLD_LIBRARY_PATH on OS X and LD_LIBRARY_PATH on Linux for -L,
and DYLD_FRAMEWORK_PATH on OS X for -F.
Note that this commit doesn't actually include the setenv calls yet, so an
end-to-end test is coming in the next commit.
Part of rdar://problem/23588774
The "Tool" abstraction wasn't buying us enough to deserve the added
complexity. Now a ToolChain turns Actions into Jobs, and every helper
tool is searched for relative to Swift first. Much simpler.
Swift SVN r31563
- Added a couple of new targets:
- libswiftDriver, which contains most of the driver implementation
- swift_driver, which produces the actual executable
- Added centralized version information into libswiftBasic.
- Added a new "Driver Design & Internals" document, which currently describes
the high-level design of the Swift driver.
- Implemented an early version of the functionality of the driver, including
versions of the Parse, Pipeline, Bind, Translate, and Execute driver stages.
Parse, Pipeline, and Bind are largely implemented; Translate and Execute are
early placeholders. (Translate produces "swift_driver --version" and "ld -v"
commands, while Execute performs all subtasks sequentially, rather than in
parallel.)
This is just the starting point for the Swift driver. Tests for the existing
behavior are forthcoming.
Swift SVN r10933
