[SR-1837] test/Runtime/backtrace.swift should be disabled on Android

[modocache]

Previous ID	SR-1837
Radar	None
Original Reporter	@modocache
Type	Task

Additional Detail from JIRA

Votes	0
Component/s
Labels	Task, Android, StarterBug
Assignee	None
Priority	Medium

md5: 39669a7192d32d5afd9e59590d8db749

Issue Description:

As far as I recall, libunwind isn't available as part of the Android NDK, so the part of the Swift runtime that normally emits backtraces is ifdef'd out when compiling for Android. As a result, I assume the test/Runtime/backtrace.swift would almost certainly fail on Android – it should be disabled.

Prerequisites:

• An Ubuntu 15.10 development environment capable of building Swift from source.

• A physical Android device.

Helpful skills:
Basic knowledge of C++ would help, but isn't necessary.

Starting point:

1. Follow the instructions in docs/Android.md to build and run the test suite on a physical Android device. Confirm this test still fails.

2. Backtraces appear to be disabled on Android: https://github.com/apple/swift/blob/91ffcd79a7765f631f2aef207167f5da5792cfc5/stdlib/public/runtime/Errors.cpp#L17-L21 – Confirm this is still the case by reading through how that macro is used in that file.

3. Read through test/Runtime/backtrace.swift, confirm that it does indeed test backtraces. If it does, add an unsupported: or requires: flag to the top of test/Runtime/backtrace.swift to keep it from running on platforms that don't support backtraces.