I've put these fields on the class object for now, just
so we can at least theoretically update them. A superclass
that grew left rather than right could maybe even be made
to work with this schema, but probably not.
rdar://16705821
Swift SVN r16880
We really don't need to support individual objects
this large, much less more than 4 billion fields in
a single type.
Also rearrange the fields to bring the instance
size/alignment fields closer to the class header,
just for a minor locality win.
Swift SVN r16879
We need them for reflection, and we always emit them for structs, so for consistency, always emitting them for classes isn't the worst thing.
Swift SVN r15214
This switches property/subscript dispatch to use virtual dispatch instead of static
dispatch. This currently only works for computed properties (and subscripts of
course), not stored ones yet.
Long story short, this:
class Base {
subscript() -> Int {
return 42
}
}
class Derived : Base {
@override
subscript() -> Int {
return 9
}
}
var a : Base = Derived()
print(a[])
now prints 9 instead of 42.
Swift SVN r15142
Inherited initializers are now functional: one can use an inherited
initializer to construct an object of a subclass type, and we properly
handle delegation to overridden complete object or subobject
initializers as appropriate. See the executable test.
This commit also contains various fixes for the IRGen side of vtable
emission and use. Proper IRGen tests still to come.
For now, we're still performing peer delegation from a subobject
initializer to another subobject initializer, hence the SILGen hack
for identifying when we're in a complete object vs. a subobject
initializer. We'll be banning delegation from subobject initializers,
so this hack---along with the peer_method instruction---will be going
away in the near future.
Swift SVN r14571
Emit vtable entries for abstract initializers. When we're constructing
an object using an abstract initializer based on a metatype value that
is not statically derivable, use the vtable entry to call the
subclass's allocating constructor.
Most of the IRGen work here is hacking around the lossy SILDeclRef ->
(Code|Function)Ref -> SILDeclRef conversion. I'd feel bad about this
if John hadn't already agreed to clean this up at some point.
Swift SVN r14238
with two kinds, and some more specific predicates that clients can use.
The notion of 'computed or not' isn't specific enough for how properties
are accessed. We already have problems with ObjC properties that are
stored but usually accessed through getters and setters, and a bool here
isn't helping matters.
NFC.
Swift SVN r12593
Build a nominal type descriptor when we emit the metadata or generic metadata pattern for a nominal type, and put a reference into the formerly null slot in the struct or enum metadata. We need to make a place for them in class metadata; that'll come next.
Swift SVN r9492
In the fill function for a generic subclass metadata pattern, arrange to memcpy the field offset vectors from all of the ancestor classes into the newly-instantiated class metadata, before laying out the subclass's own fields.
Swift SVN r9299
In particular, when a nongeneric class inherits a fragile generic class, we need to populate the field offsets for the instantiated base class because we can't rely on the runtime to populate it for us.
Swift SVN r9258
We need these for dependent-layout generic classes so we know the allocation/deallocation size and alignment. When I figure out ObjC interop with generic subclasses these should move to the rodata so they get handled resiliently by the ObjC runtime, but for generic class bringup this is convenient.
Swift SVN r9249
These are the terms sent out in the proposal last week and described in
StoredAndComputedVariables.rst.
variable
anything declared with 'var'
member variable
a variable inside a nominal type (may be an instance variable or not)
property
another term for "member variable"
computed variable
a variable with a custom getter or setter
stored variable
a variable with backing storage; any non-computed variable
These terms pre-exist in SIL and IRGen, so I only attempted to solidify
their definitions. Other than the use of "field" for "tuple element",
none of these should be exposed to users.
field
a tuple element, or
the underlying storage for a stored variable in a struct or class
physical
describes an entity whose value can be accessed directly
logical
describes an entity whose value must be accessed through some accessor
Swift SVN r8698
Standardize on the more-common "superclass" and "subclass" terminology
throughout the compiler, rather than the odd mix of base/derived and
super/sub.
Also, have ClassDecl only store the Type of the superclass. Location
information will be part of the inheritance clause for parsed classes.
Swift SVN r6687
ObjC methods always need to be invoked through objc_msgSend, so they shouldn't have vtable slots, and Swift subclasses that override ObjC methods should always insert override slots into their vtables.
Swift SVN r3889
The principal difficulty here is that we need accessing the
value witness table for a type to be an efficient operation,
but there (obviously) isn't a VWT field for ObjC classes.
Placing this field after the metatype would tend to bloat
metatypes by quite a bit. Placing it before is best, but
it introduces an unfortunate difference between the address
point of a metatype and the address of the global symbol.
That, however, can be fixed with appropriate linker support.
Still, for now this is rather unfortunately over-subtle.
Swift SVN r3307
of a class is part of the class members section and is not
global to the entire class metadata. This is crucial for
correct operation of functions expecting a base-class
metadata object.
That gives us the correct foundation to implement an
optimization under which generic arguments that can be
inferred from the 'this' pointer need not actually be
separately passed. This has the important result of
making all class member functions with the same signature
up to abstraction actually have the same physical
signature.
Swift SVN r2936
uncurrying level, which is something I find myself passing around
quite a bit. Make sure that it can propagate getter/setter
references in the same way.
Swift SVN r2902
the metadata objects for classes. This is currently only
done for methods defined in the main class body, and it's
(naturally) totally fragile, and it's screwed up in a
couple known ways w.r.t. generic classes: there's no
thunking when the overrider differs by abstraction from
the overridden method, and methods on classes currently
expect to get all the type arguments passed directly
and thus will disagree in signature from members of
non-generic classes. Also, of course, we're not using
any of this in the call infrastructure. But it's progress.
Swift SVN r2901
