The descriptor map is keyed by a simplified mangling that canonicalizes the differences that we accept in _contextDescriptorMatchesMangling, such as the ability to specify any kind of type with an OtherNominalType node.
This simplified mangling is not necessarily unique, but we use _contextDescriptorMatchesMangling for the final equality checking when looking up entries in the map, so occasional collisions are acceptable and get resolved when probing the table.
The table is meant to be comprehensive, so it includes all descriptors that can be looked up by name, and a negative result means the descriptor does not exist in the shared cache. We add a flag to the options that can mark it as non-definitive in case we ever need to degrade this, and fall back to a full search after a negative result.
The map encompasses the entire shared cache but we need to reject lookups for types in images that aren't loaded. The map includes an image index which allows us to cheaply query whether a given descriptor is in a loaded image or not, so we can ignore ones which are not.
TypeMetadataPrivateState now has a separate sections array for sections within the shared cache. _searchTypeMetadataRecords consults the map first. If no result is found in the map and the map is marked as comprehensive, then only the sections outside the shared cache need to be scanned.
Replace the SWIFT_DEBUG_ENABLE_LIB_PRESPECIALIZED environment variable with one specifically for metadata and one for descriptor lookup so they can be controlled independently. Also add SWIFT_DEBUG_VALIDATE_LIB_PRESPECIALIZED_DESCRIPTOR_LOOKUP which consults the map and does the full scan, and ensures they produce the same result, for debugging purposes.
Enhance the environment variable code to track whether a variable was set at all. This allows SWIFT_DEBUG_ENABLE_LIB_PRESPECIALIZED to override the default in either direction.
Remove the disablePrespecializedMetadata global and instead modify the mapConfiguration to disable prespecialized metadata when an image is loaded that overrides one in the shared cache.
rdar://113059233
This library uses GenericMetadataBuilder with a ReaderWriter that can read data and resolve pointers from MachO files, and emit a JSON representation of a dylib containing the built metadata.
We use LLVM's binary file readers to parse the MachO files and resolve fixups so we can follow pointers. This code is somewhat MachO specific, but could be generalized to other formats that LLVM supports.
rdar://116592577
We need to be able to locate `swift-backtrace` relative to the current
location of the runtime library.
This needs to work:
* In a Swift build directory.
* On Darwin, where we're installed in /usr/lib/swift and /usr/libexec/swift.
* On Linux, where we're in /usr/lib/swift/linux and /usr/libexec/swift/linux.
* On Windows, where we may be in a flat directory layout (because of limitations
of Windows DLL lookups).
rdar://103071801
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
Moved all the threading code to one place. Added explicit support for
Darwin, Linux, Pthreads, C11 threads and Win32 threads, including new
implementations of Once for Linux, Pthreads, C11 and Win32.
rdar://90776105
Fill out the metadata for Job to have a Dispatch-compatible vtable. When available, use the dispatch_enqueue_onto_queue_4Swift to enqueue Jobs directly onto queues. Otherwise, keep using dispatch_async_f as we have been.
rdar://75227953
There are a few environment variables used to enable debugging options in the
runtime, and we'll likely add more over time. These are implemented with
scattered getenv() calls at the point of use. This is inefficient, as most/all
OSes have to do a linear scan of the environment for each call. It's also not
discoverable, since the only way to find these variables is to inspect the
source.
This commit places all of these variables in a central location.
stdlib/public/runtime/EnvironmentVariables.def defines all of the debug
variables including their name, type, default value, and a help string. On OSes
which make an `environ` array available, the entire array is scanned in a single
pass the first time any debug variable is requested. By quickly rejecting
variables that do not start with `SWIFT_`, we optimize for the common case where
no debug variables are set. We also have a fallback to repeated `getenv()` calls
when a full scan is not possible.
Setting `SWIFT_HELP=YES` will print out all available debug variables along with
a brief description of what they do.
