We've had a rash of bugs due to inconsistencies between how IRGen and the runtime think types are laid out. Add a '-verify-type-layout' mode to the frontend that causes IRGen to emit a bunch of code that compares its static assumptions against what the runtime value witness does.
Swift SVN r24918
Teach IRGen and the runtime about the extra inhabitants
of function pointers, and take advantage of that in
thin and thick function types.
Also add runtime entrypoints for thin function type
metadata.
Swift SVN r24346
We were using std::function that allocated memory. Unfortunately c++ lambdas
don't have a type so I had to make the function findOrAdd templated on the
type of the callback. This is not a big deal since the class is already
templated and there is a single call site.
Swift SVN r23919
swift_retain and objc_retain both handle nil already, so we can bypass the generic Optional value witnesses when instantiating Optional on a class type, which happens kind of a lot.
Swift SVN r23613
If, after layout, we recognize that a generic struct or enum instance is POD, we can replace the generic value witnesses in the image with POD ones.
Swift SVN r23609
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
When there's no init function, we can do relaxed loads and stores, because the metadata record will not change in the course of canonicalization. However, if there is initialization, we need to do a release-consume in order to ensure the initialization is visible to readers.
Swift SVN r23119
The race here was benign--we just end up writing the same uniqued value twice to the invasive cache. Relax the assertion that this used to trip.
Swift SVN r23098
The AtomicInt validation test exposed a race here when multiple threads fell into the slow path. Avoid this in the expedient way by locking before the fast path, which sucks but is at least correct.
Swift SVN r23086
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
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
layouts. Introduce new SIL instructions to initialize
and open existential metatype values.
Don't actually, y'know, lift any of the restriction on
existential metatypes; just pointlessly burn extra
memory storing them.
Swift SVN r22592
- A spot fix in SILGen for reabstracting the result of a downcast, which fixes checked casts to function types.
- Associate the layout information in type metadata records with the most abstract representation of the type. This is the correct thing to do in cases where we need the metadata as a tag for an opaque value--if we store a value in an Any, or pass it as an unconstrained generic parameter, we must maximally reabstract it. This fixes the value semantics of existentials containing trivial metatypes.
- To ensure that we get runtime layout of structs and enums correct when they contain reabstractable types, introduce a "metadata for layout" concept, which doesn't need to describe the canonical metadata for the type, but only needs to describe a type with equivalent layout and value semantics. This is a correctness fix that allows us to correctly lay out generic types containing dependent tuples and functions, and although we don't really take advantage of it here, it's also a potential runtime performance win down the road, because we could potentially produce direct metadata for a primitive type that's layout-equivalent with a runtime-instantiated type. To aid in type safety here, push SILType deeper into IRGen in places where we potentially care about specific representations of types.
- Finally, fix an inconsistency between the runtime and IRGen's concept of what spare bits unmanaged references and thick metatypes have.
Together, these fixes address rdar://problem/16406907, rdar://problem/17822208, rdar://problem/18189508, and likely many other related issues, and also fixes crash suite cases 012 and 024.
Swift SVN r21963
pass the size and alignment of each field. Take advantage
of this to pass a constant size and alignment when
possible.
This avoids the need to recursively find type metadata for
every field type, allowing generic recursively-structured
classes to be built. There are a number of more complicated
cases that this approach isn't good enough for, but this
is good enough for now to fix rdar://18067671.
Also make an effort to properly support generic subclasses
of Objective-C classes.
Swift SVN r21506
The allocator's crimes include:
* It uses OS SPI that must not be used by non-OS apps.
* It does not play well with memory debugging tools like Instruments.
* It does not return memory to the OS in response to memory pressure.
* It is less tested than we would like because many configurations
inadvertently turn it off (such as running from Xcode).
* Its per-thread magazine implementation does not actually work.
* Its "try alloc" flag is incompletely implemented and never used.
* Its "zero fill" flag is unimplemented and inconsistently used.
Swift SVN r20757
initializeBufferWithTakeOfBuffer value witness.
Attempt to use initializeBufferWithTakeOfBuffer in
some appropriate places.
There are some changes enabled by this which are
coming in a follow-up patch.
Swift SVN r20741
unexpected forematter from the superclass.
This requires a pretty substantial shift in the
generic-metadata allocation/initialization dance
because (1) we can't allocate class metadata without
knowing what the superclass is and (2) the offset
from the metadata cache entry to the address point is
no longer determined solely by the metadata pattern.
While I'm making invasive changes to metadata, fix
two race conditions in metadata creation. The first
is that we need to ensure that only one thread succeeds
at lazily creating a generic-metadata cache. The second
is that we need to ensure that only one thread actually
attempts to create a particular metadata; any others
should block until the metadata is successfully built.
This commit finishes rdar://17776354. LLDB will
need to adjust to the runtime-private metadata layout
changes.
Swift SVN r20537
Narrowly address the problem of downcasting an array to an array of
Objective-C existentials by checking conformance for Objective-C
protocols. Addresses <rdar://problem/17165071>, but this area still
needs a lot of work.
Swift SVN r18745
Blocks need their own type metadata with value witnesses appropriate to the block representation. Fixes <rdar://problem/16918740> and <rdar://problem/16981126>.
Swift SVN r18508
UIViewController is able to find nib files that have names derived from the
UIViewController subclass's name. This change modifies UIViewController's
lookup so it is able to find nib files for Swift class names.
Swift SVN r18470
This not only removes some code, but should allow more optimization and
inlining in the common case where the Swift type is a class or @objc
existential such as AnyObject
Swift SVN r18237
