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.
An upcoming change has the SIL Optimizer drop the [fragile]
attribute from the specialized callee, unless the caller
is itself [fragile].
Since we need to distinguish specializations from fragile
and non-fragile contexts, add a new mangling node to
represent this concept.
initialization in-place on demand. Initialize parent metadata
references correctly on struct and enum metadata.
Also includes several minor improvements related to relative
pointers that I was using before deciding to simply switch the
parent reference to an absolute reference to get better access
patterns.
Includes a fix since the earlier commit to make enum metadata
writable if they have an unfilled payload size. This didn't show
up on Darwin because "constant" is currently unenforced there in
global data containing relocations.
This patch requires an associated LLDB change which is being
submitted in parallel.
Rename BlotMapVector's template typenames: MapTy -> MapT and VectorTy -> VectorT. This is consistent both with BlotMapVector's other template typename KeyT and ValueT, and with SmallBlotMapVector's MapT and VectorT template typenames.
Before the refactor, a dangling reference to a string may be stored in a DemanglePrinter in at least the following cases:
1) If an lvalue DemanglePrinter is initialized with an rvalue string:
DemanglePrinter printer("abc");
2) If an lvalue DemanglePrinter is initialized with an lvalue string which doesn't live as long as the printer:
unique_ptr<DemanglePrinter> printer;
{
std::string s = "abc";
printer = make_unique<DemanglePrinter>(s);
}
// Reference stored in printer is dangling
In addition, in all existing cases in the code where an lvalue DemanglePrinter is used, an empty string is initialized just before it, which isn't DRY, and is related to the previous problem - the coder shouldn't be expected to maintain the lifetime of a string separate from the DemanglePrinter which references it.
In addition, before the refactor, in any in-line use of DemanglePrinter it is constructed with an empty string parameter (in which to construct the string), but this doesn't look very clean.
The refactor solves the above issues by maintaining its own string as a member, while still enabling the original intent of being able to use DemanglePrinter both as an lvalue constructively before getting its value, and in-line as an rvalue.
Add the constexpr version of max which is only available in std since c++14.
Besides being a logical addition next to the already implemented constexpr version of min, there are actually other files, even in Swift/Basic itself, which re-implement this functionality, such as PrefixMap.h. Once this is implemented here, the functionality can be re-used in those other locations, instead of re-implemented each time.
