References to functions that take inout parameters crash the compiler
because InOutType isn't a "real" type in itself and has no special type
metadata to emit. It merely further qualifies the function's input
types.
For example, we would like to have a unique entry in the cache for:
var f: (T, T) -> ()
and
var f2: (inout T, T) -> ()
For each argument type metadata pointer in the function's input, take
advantage of pointer alignment and mark the lowest bit if it is inout.
Since the metadata cache uses pointers to create the key, this creates a
unique entry while still being able to extract the actual pointer.
This fixes <rdar://problem/17655125>, and a couple of other similar
crashes.
Swift SVN r23557
This works by loading the protocols from a specially named symbol,
which is generated by the linker through the help of a linker script
that merges all of the protocol conformance blocks into one section
with its size at the start of it and points a global symbol at
the section.
We do all this because unlike MachO, section information does not
survive to be loaded into memory with ELF binaries. Instead,
the mappings that survive are 'segments', which contain one or
more sections. Information about how these relate to their original
sections is difficult, if not impossible, to obtain at runtime.
Swift SVN r23518
This works by loading the protocols from a specially named symbol,
which is generated by the linker through the help of a linker script
that merges all of the protocol conformance blocks into one section
with its size at the start of it and points a global symbol at
the section.
We do all this because unlike MachO, section information does not
survive to be loaded into memory with ELF binaries. Instead,
the mappings that survive are 'segments', which contain one or
more sections. Information about how these relate to their original
sections is difficult, if not impossible, to obtain at runtime.
Swift SVN r23475
This is acting as a temporary work around until the more general
getTypeKind() is finalized from an API perspective.
The reason that removing this now instead of waiting makes sense is:
1. The previous way playgrounds was performing this check was using the runtime
c++ implementation of swift_isClassOrObjCExistential via @asmname. We
want to move away from the @asmname approach in general since it is
brittle since it leads to loose cupling of dependencies.
2. The @asmname version in playgrounds caused the deserializer to assert since
the c++ version of swift_isClassOrObjCExistential() does not match the signature
of the swift declaration of swift_isClassOrObjCExistential().
This allows us to avoid the aforementioned issues and make forward
progress on re-enabling the playground logger with optimization.
rdar://18841292
Swift SVN r23307
Handle a null conformances pointer in _conformsToProtocol, and when we want to overwrite a metatype, pass a correct conformances pointer for the existential metatype value.
Swift SVN r23304
These always fail, and it doesn't make sense to inline this check into the cast site, so provide additional runtime functions for metatype-to-objc-existential casts.
Swift SVN r23237
This exposes an issue with CF types. Looking up their dynamic types gives us an ObjC class, which doesn't necessarily have the same protocol conformances (and for non-bridged types is just NSObject).
Swift SVN r23153
Another thread could pull enqueued records into the cache while we're waiting on the lock, leaving us with an empty queue but an updated cache. Recognize this by sticking a generation on the cache and retrying instead of failing if the generation increased while we waited. Fixes rdar://problem/18856858.
Swift SVN r23091
Move the uniquing information for ForeignTypeMetadata behind the address point so we can share the layout between foreign classes and the existing layout for struct and enum metadata. Emit metadata records for imported structs and enums as foreign metadata candidates, and dynamically unique references to the metadata by calling swift_getForeignTypeMetadata.
Swift SVN r23081
As a stopgap till IRGen properly emits indirected class references, support direct class reference protocol conformance records. This should get us to the point we can replace the dlsym hack with the new implementation.
Swift SVN r23073
We should unique foreign struct/enum metadata the same way we do CF foreign class metadata, but for now, treat them as direct references like we do in IRGen.
Swift SVN r23072
We can share a lookup cache entry under the generic metadata pattern when the witness table for a protocol conformance is shared among all instances of the type. (This happens to always be the case currently.)
Swift SVN r23062
Set up the basic logic for first looking into a cache then pulling in conformances from enqueued images and trying again for exact-matchable types (pretty much just nongeneric native value types).
Swift SVN r23053
Set up lazy registration of a dyld add image callback that looks up the "__DATA,__swift1_proto" section in the loaded image. As a first-pass sanity check, just walk the section and dump the records.
Swift SVN r23025
Rename the existing misleadingly-named "isClassType" to "isClassObject", and document that it refers to (swift or ObjC) class objects, the latter of which aren't always type metadata.
Swift SVN r22153
