This is better than the `alternativePaths` mechanism because it means that
a client of the `Runtime` module can do its own thing, which might even
mean fetching things from a remote server or decompressing files or any
other thing we might find useful.
rdar://170642627
Instead of the symbolication method being decided by what platform the symbolication code is running on, use a parameter passed to the symbolication function, defaulted to the current platform for backward compatibility.
Useful for the upcoming offline symbolicator.
rdar://168769519
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---------
Co-authored-by: Carl Peto <carlpeto@Carls-MacBook-Pro.local>
This doesn't have a working symbolicator yet, but it does build and
it can obtain a basic backtrace.
It also doesn't include a working `swift-backtrace` program yet.
rdar://101623384
Added some explanatory text to the Compact Backtrace Format
documentation, and also to the `CMakeLists.txt` for the runtime.
Tweaked the conversions for `Backtrace.Address` to truncate, which
should result in reasonable behaviour for negative fixed-width
integers.
Use a constant for the ASCII values for `/` and `\` in the Compact
Image Format encoder/decoder.
Make the TSD key for `ElfImageCache` non-optional, and call
`fatalError()` if we don't get one.
rdar://124913332
Move the backtracing code into a new Runtime module. This means renaming
the Swift Runtime's CMake target because otherwise there will be a name
clash.
rdar://124913332
