We currently have an element in the solution score related to whether we
had a binding or equality constraint involving Any.
Doing this yields some strange results, e.g. if overload resolution
results in a property declared as Any we end up discarding that solution
in favor of solutions that involve other overloads that are not declared
as Any but are also not actually better solutions (e.g. overloads that
are declared as function types).
We really want to retain both solutions in this case and allow the
ranking step of the solver to decide on the better choice.
Fixes rdar://problem/29374163, rdar://problem/29691909.
- The DeclContext versions of these methods have equivalents
on the DeclContext class; use them instead.
- The GenericEnvironment versions of these methods are now
static methods on the GenericEnvironment class. Note that
these are not made redundant by the instance methods on
GenericEnvironment, since the static methods can also be
called with a null GenericEnvironment, in which case they
just assert that the type is fully concrete.
- Remove some unnecessary #includes of ArchetypeBuilder.h
and GenericEnvironment.h. Now changes to these files
result in a lot less recompilation.
Changes:
* Terminate all namespaces with the correct closing comment.
* Make sure argument names in comments match the corresponding parameter name.
* Remove redundant get() calls on smart pointers.
* Prefer using "override" or "final" instead of "virtual". Remove "virtual" where appropriate.
This function had a weird, pre-ProtocolConformanceRef interface that
returned true when the type conformed to the protocol, then had a
separate indirect return value for the concrete conformance (if there
is one). Refactor this API, and the similar
TypeChecker::containsProtocol(), to produce an optional
ProtocolConformanceRef, which is far more idiomatic and easier to
use. Push ProtocolConformanceRef into a few more places. Should be NFC
There's a bit of a hack to deal with generic typealiases, but
overall this makes things more logical.
This is the last big refactoring before we can allow constrained
extensions to make generic parameters concrete. All that remains
is a small set of changes to SIL type lowering, and retooling
some diagnostics in Sema.
Long term, we want to refactor the AST to reflect the current
programming model in Swift. This would include refactoring
FunctionType to take a list of ParameterTypeElt, or something with a
better name, that can contain both the type and flags/bits that are
only specific to types in parameter position, such as @autoclosure and
@escaping. At the same time, noescape-by-default has severely hurt our
ability to print types without significant context, as we either have
to choose to too aggressively print @escaping or not print it in every
situation it occurs, or both.
As a gentle step towards the final solution, without uprooting our
overall AST structure, and as a way towards fixing the @escaping
printing ails, put these bits on the TupleTypeElt and ParenType, which
will serve as a model for what ParameterTypeElt will be like in the
future. Re-use these flags on CallArgParam, to leverage shared
knowledge in the type system. It is a little painful to tack onto
these types, but it's minor and will be overhauled soon, which will
eventually result in size savings and less complexity overall.
This includes all the constraint system adjustments to make these
types work and influence type equality and overload resolution as
desired. They are encoded in the module format. Additional tests
added.
Now that TupleTypeElts are simpler in Swift 3 (though they're about to
become more complicated for other reasons), most of the cases where we
are explicitly constructing ones are really just plain copies or can
otherwise use existing helper functions.
NFC
This eliminates a pile of now-dead code in:
* The type checker, where we no longer have special cases for bridging conversions
* The expression ASTs, where we no longer need to distinguish bridging collection up/down casts
* SILGen, which no longer uses
Still to come is the removal of the
_(set|dictionary)Bridge(From|To)ObjectiveC(Conditional)? entrypoints
from the standard library. They're still used by some tests.
When referencing a function in the type checker, drop argument labels
when we don't need them to type-check an immediate call to that
function. This provides the semantic behavior of SE-0111, e.g.,
references to functions as values produce unlabeled function types,
without the representational change of actually dropping argument
labels from the type system.
At the moment, this only works for bare references to functions. It
still needs to be pushed through more of the type checker and more AST
nodes to work in the general case.
Keep this work behind the frontend flag
-suppress-argument-labels-in-types for now.
Rather than synthesizing a global operator '==' for Equatable enums,
synthesize a member operator, which is more idiomatic and much
cleaner.
To make sure that these synthesized operators can actually be found,
start considering operator requirements in protocols
more generally in the type checker, so that, e.g., "myEnum == myEnum"
will type-check against Equatable.== and, on successful type-check,
will call the (newly-synthesized) witness for '=='. This both makes it
easier to make sure we find the operators in, e.g., complex multi-file
and lazy-type checking scenarios, and is a step toward the
type-checking improvements described in SE-0091.
In Swift, default arguments are associated with a function or
initializer's declaration---not with its type. This was not always the
case, and TupleType's ability to store a default argument kind is a
messy holdover from those dark times.
Eliminate the default argument kind from TupleType, which involves
migrating a few more clients over to declaration-centric handling of
default arguments. Doing so is usually a bug-fix anyway: without the
declaration, one didn't really have
The SILGen test changes are due to a name-mangling fix that fell out
of this change: a tuple type is mangled differently than a non-tuple
type, and having a default argument would make the parameter list of a
single-parameter function into a tuple type. Hence,
func foo(x: Int = 5)
would get a different mangling from
func foo(x: Int)
even though we didn't actually allow overloading.
Fixes rdar://problem/24016341, and helps us along the way to SE-0111
(removing the significance of argument labels) because argument labels
are also declaration-centric, and need the same information.
- Change openGeneric() to take two DeclContexts, one is the generic
context for the signature and the second is the generic context
containing the declaration being opened
- This allows us to clean up the logic around skipProtocolSelfRequirement;
instead of testing both the DeclContext and its parent, we know
exactly what DeclContext to test. Also, use the right Self type here,
instead of always using (0, 0)
- Now that we have the right DeclContexts handy, we can move the
getGenericTypeContextDepth() call into openGeneric(), simplifying
callers
- Now that openType() no longer opens generic signatures, it takes fewer
parameters
Rather than relying on the embedding of default argument information
into tuple types (which is gross), make sure that the various clients
(type checker, type checker diagnostics, constraint application) can
dig out the callee declaration and retrieve that information from
there.
a generic function type during constraint solving, as opposed to
checking a bunch of implicit things that we already know. This
should significantly improve the efficiency of checking uses of
generic APIs by reducing the total number of type variables and
constraints.
It is becoming increasingly funny to refer to this minimized generic
signature as the "mangling" signature.
The test changes are kind of a wash: in one case, we've eliminated
a confusing extra error, but in another we've caused the confusing
extra error to refer to '<<error type>>'. Not worth fighting right
now. The reference-dependencies change is due to not needing to
pull in all of those associated types anymore, which seems correct.
There's a group of methods in `DeclContext` with names that start with *is*,
such as `isClassOrClassExtensionContext()`. These names suggests a boolean
return value, while the methods actually return a type declaration. This
patch replaces the *is* prefix with *getAs* to better reflect their interface.
When comparing two functions for overload resolution, break apart the
parameter lists to compare individual parameters rather than comparing
the tuples. This allows us to prefer functions with fewer arguments to
ones with more, defaulted or variadic arguments. That preference was
already encoded in the constraint optimizer, which led to some strange
behavior where the preference was expressed for function calls but not
for calls to initializers. Fixes rdar://problem/24128153.
The standard library change tweaks the anachronistic, unavailable
"print" variants somewhat. The only behavior change here is a slight
regression for cases like:
print(a: 1, b: 2)
where we used to produce a diagnostic:
Please wrap your tuple argument in parentheses: 'print((...))'
but we now get:
argument labels '(a:, b:)' do not match any available overloads
However, this regression will happen at some point *anyway*, if
SE-0029 (or anything else that removes the implicit tuple splat
operation) goes through.
Note that the typecheck perf for these kinds of expressions still isn't fantastic, but at least they're now computationally feasible. I have further improvements planned for this area which should bring performance in line with expectations.
isGenericContext() returning true doesn’t necessarily imply that getGenericSignature() returns non-null. getGenericSignatureOfContext() performs a traversal equivalent to isGenericContext(), so we use it instead.
Eliminate the last client of DependentTypeOpener,
RequirementTypeOpener, which tracked the opened Self type when doing
witness/requirement matching and substituted in the known type
witnesses for that protocol. It had a bunch of dead logic hanging
around from the days where we used the constraint system to deduce
type witnesses. Now, a simple substitution suffices.
With its last client gone, remove DependentTypeOpener as well.
The ArchetypeOpener was used only to replace dependent types with
archetypes (or concrete types) within the opening context. We can do
the same simply by letting the constraint system create type variables
and then binding those type variables to the appropriate
archetypes/concrete types in that context.
Eliminate the two DependentTypeOpener entry points that were only used
by the ArchetypeOpener.
Parameters (to methods, initializers, accessors, subscripts, etc) have always been represented
as Pattern's (of a particular sort), stemming from an early design direction that was abandoned.
Being built on top of patterns leads to patterns being overly complicated (e.g. tuple patterns
have to have varargs and default parameters) and make working on parameter lists complicated
and error prone. This might have been ok in 2015, but there is no way we can live like this in
2016.
Instead of using Patterns, carve out a new ParameterList and Parameter type to represent all the
parameter specific stuff. This simplifies many things and allows a lot of simplifications.
Unfortunately, I wasn't able to do this very incrementally, so this is a huge patch. The good
news is that it erases a ton of code, and the technical debt that went with it. Ignoring test
suite changes, we have:
77 files changed, 2359 insertions(+), 3221 deletions(-)
This patch also makes a bunch of wierd things dead, but I'll sweep those out in follow-on
patches.
Fixes <rdar://problem/22846558> No code completions in Foo( when Foo has error type
Fixes <rdar://problem/24026538> Slight regression in generated header, which I filed to go with 3a23d75.
Fixes an overloading bug involving default arguments and curried functions (see the diff to
Constraints/diagnostics.swift, which we now correctly accept).
Fixes cases where problems with parameters would get emitted multiple times, e.g. in the
test/Parse/subscripting.swift testcase.
The source range for ParamDecl now includes its type, which permutes some of the IDE / SourceModel tests
(for the better, I think).
Eliminates the bogus "type annotation missing in pattern" error message when a type isn't
specified for a parameter (see test/decl/func/functions.swift).
This now consistently parenthesizes argument lists in function types, which leads to many diffs in the
SILGen tests among others.
This does break the "sibling indentation" test in SourceKit/CodeFormat/indent-sibling.swift, and
I haven't been able to figure it out. Given that this is experimental functionality anyway,
I'm just XFAILing the test for now. i'll look at it separately from this mongo diff.
Previously, methods on DeclContext for getting generic parameters
and signatures did not walk up from type contexts to function
contexts, or function contexts to function contexts.
Presumably this is because SIL doesn't completely support nested
generics yet, instead only handling these two special cases:
- non-generic local function inside generic function
- generic method inside generic type
For local functions nested inside generic functions, SIL expects
the closure to not have an interface type or generic signature,
even if the contextual type signature contains archetypes.
This should probably be revisited some day.
Recall that these cases are explicitly rejected by Sema diagnostics
because they lack SIL support:
- generic function inside generic function
- generic type inside generic function
After the previous patches in this series, it becomes possible to
construct types that are the same as before for the supported uses of
nested generics, while introducing a more self-consistent conceptual
model for the unsupported cases.
Some new tests show we generate diagnotics in various cases that
used to crash.
The conceptual model might still not be completely right, and of
course SIL, IRGen and runtime support is still missing.
Now that generic signatures of types include generic parameters
introduced by outer generic functions, we need to know to skip
them when forming bound generic types or substitutions.
Add a function that computes the depth of the innermost generic
context that is not a generic type context.
My temporary hackery around inferring default arguments from imported
APIs was too horrible. Make it slightly more sane by:
1) Actually marking these as default arguments in the type system,
rather than doing everything outside of the type system. This is a
step closer to what we would really do, if we go in this
direction. Put it behind the new -frontend flag
-enable-infer-default-arguments.
2) Only inferring a default argument from option sets and from
explicitly "nullable" parameters, as stated in the (Objective-)C API
or API notes. This eliminates a pile of spurious, non-sensical "=
nil"'s in the resulting output.
Note that there is one ugly tweak to the overloading rules to prefer
declarations with fewer defaulted arguments. This is a bad
implementation of what is probably a reasonable rule (prefer to bind
fewer default arguments), which intentionally only kicks in when we're
dealing with imported APIs that have default arguments.
Swift SVN r32078
There's still work left to do. In terms of next steps, there's still rdar://problem/22126141, which covers removing the 'workaround' overloads for print (that prevent bogus overload resolution failures), as well as providing a decent diagnostic when users invoke print with 'appendNewline'.
Swift SVN r30976
