- Continue adding support for checked downcasts of array types (rdar://problem/16535104)
- Fix non-bridged array conversions post-r17868
- Fix rdar://problem/16773693
- Add tests for NSArray coercions to and from Array<T>
Swift SVN r17957
when resolving identifiers into types. This will eventually allow us to
solve annoying issues like rdar://15295763&15588967 by better modeling
what we already have.
Swift SVN r16620
Teach SILGen to handle function representation changes as part of function conversion instead of needing to be spoonfed a special expr for the purpose. Handle representation changes in both directions to and from blocks using the same logic as the bridging conversions.
Swift SVN r16318
Add a third branch to the constraint system for '&x' expressions that allows conversion from an lvalue to a type via an additional writeback step:
- Add an LValueConversionExpr node that converts from @lvalue T to @lvalue U, given a pair of functions that convert T -> U and U -> T, to represent the writeback temporary.
- Allow conversion in an inout expression from @lvalue T to a type U that has the following members:
static func __writeback_conversion(Builtin.RawPointer, T.Type) -> U
static func __writeback_conversion_get(T) -> V
static func __writeback_conversion_set(V) -> T
which builds a solution that produces an LValueConversion from the get/set pair before passing the pointer to the writeback temporary off to the conversion function.
Swift SVN r15764
Add two new AST node types:
- InOutConversionExpr, which represents an '&x' expression that involves inout conversion. This will be a signal to SILGen not to introduce a writeback scope for the nested conversion call.
- LValueToPointerExpr, which represents the primitive '@lvalue T' to 'RawPointer' conversion that produces the argument to the inout conversion.
Build an InOutConversionExpr AST when an inout expression is resolved by a conversion to an BuiltinInOutAddressConvertible type.
Swift SVN r15594
Factor an IdentityExpr base class out of ParenExpr, and migrate most of the logic to see through ParenExprs to see through IdentityExprs instead. Add DotSelfExpr as a new subclass of IdentityExpr, produced by parsing 'x.self'.
Swift SVN r14381
When applying a function that was produced via a covariant function
conversion, strip off that covariant function conversion and introduce
a covariant (function or return) conversion outside of the
application. This allows us to perform the covariant conversion very
late, eliminating the need to produce reabstraction thunks for any
call to a DynamicSelf method.
Swift SVN r13779
Introduce a new expression kind, OpenExistentialExpr, that "opens" up
an existential value into a value of a fresh archetype type that
represents the dynamic type of the existential. That value can be
referenced (via an OpaqueValueExpr) within the within the
subexpression of OpenExistentialExpr. For example, a call to a
DynamicSelf method on an existential looks something like this:
(open_existential_expr implicit type='P'
(opaque_value_expr implicit type='opened P' @ 0x7fd95207c290
unique)
(load_expr implicit type='P'
(declref_expr type='@lvalue P' decl=t.(file).func
decl.p@t.swift:5:37 specialized=no))
(erasure_expr implicit type='P'
(call_expr type='opened P'
(archetype_member_ref_expr type='() -> opened P'
decl=t.(file).P.f@t.swift:2:8 [with Self=opened P]
(opaque_value_expr implicit type='opened P' @
0x7fd95207c290 unique))
(tuple_expr type='()')))))
Note that we're using archetype_member_ref_expr rather than
existential_member_ref_expr, because the call is operating on the
opaque_value_expr of archetype type. The outer erasure turns the
archetype value back into an existential value.
The SILGen side of this is somewhat incomplete; we're using
project_existential[_ref] to open the existential, which is almost
correct: it gives us access to the value as an archetype, but IRGen
doesn't know to treat the archetype type as a fresh archetype whose
conformances come from the existential. Additionally, the output of
the opened type is not properly parsable. I'll fix this in follow-on
commits.
Finally, the type checker very narrowly introduces support for
OpenExistentialExpr as it pertains to DynamicSelf. However, this can
generalize to support all accesses into existentials, eliminating the
need for ExistentialMemberRef and ExistentialSubscript in the AST and
protocol_method in SIL, as well as enabling more advanced existential
features should we want them later.
Swift SVN r13740
Introduce a new AST node to capture the covariant function type
conversion for DynamicSelf. This conversion differs from the normal
function-conversion expressions because it isn't inherently type-safe;
type safety is assured through DynamicSelf.
On the SIL side, map DynamicSelf down to the type of the declaring
class to keep the SIL type system consistent. Map the new
CovariantFunctionConversionExpr down to a convert_function
instruction, slightly loosening the constraints on convert_function to
allow for this (it's always been ABI-compatible-only conversions
anyway).
We currently generate awful SIL when calling a DynamicSelf method,
because SILGenApply doesn't know how to deal with the implicit return
type adjustment associated with the covariant function
conversion. That optimization will follow; at least what we have here
is (barely) functional.
Swift SVN r13286
Introduce a new AST node to capture the covariant function type
conversion for DynamicSelf. This conversion differs from the normal
function-conversion expressions because it isn't inherently type-safe;
type safety is assured through DynamicSelf.
On the SIL side, map DynamicSelf down to the type of the declaring
class to keep the SIL type system consistent. Map the new
CovariantFunctionConversionExpr down to a convert_function
instruction, slightly loosening the constraints on convert_function to
allow for this (it's always been ABI-compatible-only conversions
anyway).
We currently generate awful SIL when calling a DynamicSelf method,
because SILGenApply doesn't know how to deal with the implicit return
type adjustment associated with the covariant function
conversion. That optimization will follow; at least what we have here
is (barely) functional.
Swift SVN r13269
Now that we have a solid Optional-based story for dynamic casts, it's no longer needed, and can be expressed as '(x as T)!'. Future refinement of the 'as' syntax will deal with the unfortunate extra parens.
Swift SVN r9181
As with the monadic '?', we treat any left-bound '!' as a postfix
operator. Currently, it extracts the value of its optional
subexpression, failing at run-time if the optional is empty.
Swift SVN r8948
Parse '_' as a DiscardAssignmentExpr. Type-check it as an lvalue, and check that it only appears in the LHS of AssignExprs. During matching pattern resolution, convert it into an AnyPattern. In SILGen, when we see '_' in the LHS of an assignment, ignore the corresponding RHS rvalue.
Swift SVN r8848
Though we plan to revamp the casting syntax, our general plan is for this form of cast, which does a conditional cast and returns an Optional<T> result, to be the one that survives. Parse the status-quo syntax 'x as? T' and type-check it. While we're here, refresh some fixits for redundant casts that referred to the now defunct 'as T' coercion syntax to completely remove whatever cast was in the source code.
Swift SVN r8805
AnyFunctionRef is a universal function reference that can wrap all AST nodes
that represent functions and exposes a common interface to them. Use it in two
places in SIL where CapturingExpr was used previously.
AnyFunctionRef allows further simplifications in other places, but these will
be done separately.
Swift SVN r8239
These helper expressions will eventually be used by SILGen to help
package up the optional values. I expect that we'll eventually have
library builtins for this, so consider this a stop-gap until those
appear.
As part of this, make OpaqueValueExpr a bit more usable: it can now
persist in the AST as a placeholder, but its uses must be within AST
subtrees of some specific introduction point (similarly to how Clang's
OpaqueValueExpr works).
Swift SVN r8051
MemberRefExpr now uses ConcreteDeclRef to refer to its member, which
includes the substitutions and obviates the need for
GenericMemberRefExpr.
Swift SVN r7842
When performing member lookup into an existential that involves the
DynamicLookup protocol, look into all classes and protocols for that
member. References to anything found via this lookup mechanism are
returned as instances of Optional.
This introduces the basic lookup mechanics into the type
checker. There are still numerous issues to work through:
- Subscripting isn't supported yet
- There's no SILGen or IRGen support
- The ASTs probably aren't good enough for the above anyway
- References to generics will be broken
- Ambiguity resolution or non-resolution
Thanks to Jordan for the patch wiring up DynamicLookup.
Swift SVN r7689
This was not likely an error-free change. Where you see problems
please correct them. This went through a fairly tedious audit
before committing, but comments might have been changed incorrectly,
not changed at all, etc.
Swift SVN r7631
Because of '~=' lookahead and precedence parsing, we need to be able to parse pattern productions in expression position and validate them after name binding. Add an unresolved Expr node that can hold a subpattern for this purpose.
Swift SVN r5825
Improve our representations of casts in the AST and SIL so that 'as!' and 'is' (and eventually 'as?') can share almost all of the same type-checking, SILGen, and IRGen code.
In the AST, we now represent 'as!' and 'is' as UnconditionalCheckedCastExpr and IsaExpr, respectively, with the semantic variations of cast (downcast, super-to-archetype, archetype-to-concrete, etc.) discriminated by an enum field. This keeps the user-visible syntactic and type behavior differences of the two forms cleanly separated for AST consumers.
At the SIL level, we transpose the representation so that the different cast semantics get their own instructions and the conditional/unconditional cast behavior is indicated by an enum, making it easy for IRGen to discriminate the different code paths for the different semantics. We also add an 'IsNonnull' instruction to cover the conditional-cast-result-to-boolean conversion common to all the forms of 'is'.
The upshot of all this is that 'x is T' now works for all the new archetype and existential cast forms supported by 'as!'.
Swift SVN r5737
