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.
Introduce Fix-Its to aid migration from selectors spelled as string
literals ("foo:bar:", which is deprecated), as well as from
construction of Selector instances from string literals
(Selector("foo:bar"), which is still acceptable but not recommended),
to the #selector syntax. Jump through some hoops to disambiguate
method references if there are overloads:
fixits.swift:51:7: warning: use of string literal for Objective-C
selectors is deprecated; use '#selector' instead
_ = "overloadedWithInt:" as Selector
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#selector(Bar.overloaded(_:) as (Bar) -> (Int) -> ())
In the cases where we cannot provide a Fix-It to a #selector
expression, we wrap the string literal in a Selector(...) construction
to suppress the deprecation warning. These are also easily searchable
in the code base.
This also means we're doing more validation of the string literals
that go into Selector, i.e., that they are well-formed selectors and
that we know about some method that is @objc and has that
selector. We'll warn if either is untrue.
Since resilience is a property of the module being compiled,
not decls being accessed, we need to record which types are
resilient as part of the module.
Previously we would only ever look at the @_fixed_layout
attribute on a type. If the flag was not specified, Sema
would slap this attribute on every type that gets validated.
This is wasteful for non-resilient builds, because there
all types get the attribute. It was also apparently wrong,
and I don't fully understand when Sema decides to validate
which decls.
It is much cleaner conceptually to just serialize this flag
with the module, and check for its presence if the
attribute was not found on a type.
If a BoundGenericType is unable to get a substitution for an archetype
it uses ErrorType as the replacement (Module.cpp:705). In such a case
we should report DoesNotConform in lookupConformance(), which ends up
generating reasonable error messages. Prior to this change the
conformance would succeed and then IRGen would crash on emitting an
ErrorType during emitForeignTypeMetadataRef().
Also added test that tickles crash near the same place as SR-427.
This eliminates some minor overheads, but mostly it eliminates
a lot of conceptual complexity due to the overhead basically
appearing outside of its context.
The main idea here is that we really, really want to be
able to recover the protocol requirement of a conformance
reference even if it's abstract due to the conforming type
being abstract (e.g. an archetype). I've made the conversion
from ProtocolConformance* explicit to discourage casual
contamination of the Ref with a null value.
As part of this change, always make conformance arrays in
Substitutions fully parallel to the requirements, as opposed
to occasionally being empty when the conformances are abstract.
As another part of this, I've tried to proactively fix
prospective bugs with partially-concrete conformances, which I
believe can happen with concretely-bound archetypes.
In addition to just giving us stronger invariants, this is
progress towards the removal of the archetype from Substitution.
This is necessary for some other work I'm doing, which really wants
paramdecls to have reasonable declcontexts. It is also a small step
towards generic subscripts.
This reflects the fact that the attribute's only for compiler-internal use, and isn't really equivalent to C's asm attribute, since it doesn't change the calling convention to be C-compatible.
The lookup cache isn't allocated in the ASTContext, so seting up a
destructor cleanup isn't sufficient to get the memory released. Luckily
SourceFile and BuiltinUnit already have their own destructor called, so
we can use std::unique_ptr.
rdar://problem/22387897
Swift SVN r31561
the regressions that r31105 introduced in the validation tests, as well as fixing a number
of other validation tests as well.
Introduce a new UnresolvedType to the type system, and have CSDiags start to use it
as a way to get more type information out of incorrect subexpressions. UnresolvedType
generally just propagates around the type system like a type variable:
- it magically conforms to all protocols
- it CSGens as an unconstrained type variable.
- it ASTPrints as _, just like a type variable.
The major difference is that UnresolvedType can be used outside the context of a
ConstraintSystem, which is useful for CSGen since it sets up several of them to
diagnose subexpressions w.r.t. their types.
For now, our use of this is extremely limited: when a closureexpr has no contextual
type available and its parameters are invalid, we wipe them out with UnresolvedType
(instead of the previous nulltype dance) to get ambiguities later on.
We also introduce a new FreeTypeVariableBinding::UnresolvedType approach for
constraint solving (and use this only in one place in CSDiags so far, to resolve
the callee of a CallExpr) which solves a system and rewrites any leftover type
variables as UnresolvedTypes. This allows us to get more precise information out,
for example, diagnosing:
func r22162441(lines: [String]) {
lines.map { line in line.fooBar() }
}
with: value of type 'String' has no member 'fooBar'
instead of: type of expression is ambiguous without more context
This improves a number of other diagnostics as well, but is just the infrastructural
stepping stone for greater things.
Swift SVN r31130
as a way to get more type information out of incorrect subexpressions. UnresolvedType
generally just propagates around the type system like a type variable:
- it magically conforms to all protocols
- it CSGens as an unconstrained type variable.
- it ASTPrints as _, just like a type variable.
The major difference is that UnresolvedType can be used outside the context of a
ConstraintSystem, which is useful for CSGen since it sets up several of them to
diagnose subexpressions w.r.t. their types.
For now, our use of this is extremely limited: when a closureexpr has no contextual
type available and its parameters are invalid, we wipe them out with UnresolvedType
(instead of the previous nulltype dance) to get ambiguities later on.
We also introduce a new FreeTypeVariableBinding::UnresolvedType approach for
constraint solving (and use this only in one place in CSDiags so far, to resolve
the callee of a CallExpr) which solves a system and rewrites any leftover type
variables as UnresolvedTypes. This allows us to get more precise information out,
for example, diagnosing:
func r22162441(lines: [String]) {
lines.map { line in line.fooBar() }
}
with: value of type 'String' has no member 'fooBar'
instead of: type of expression is ambiguous without more context
This improves a number of other diagnostics as well, but is just the infrastructural
stepping stone for greater things.
Swift SVN r31105
This changes the behavior to match NominalTypeDecls, which don't have a type
until everything is set up either. In a few places we construct TypeAliasDecls
from known types directly, and we have to call computeType().
Fixes <rdar://problem/19534837>.
Swift SVN r30386
Specifically track when we're resolving type witnesses for a given
conformance, and refuse to recursively attempt to resolve those type
witnesses. The standard library patch in rdar://problem/21789238
triggers this, and isolating it in a small test case has proven
illusive.
Swift SVN r30160
The isDependentType() query is woefully misunderstood. Some places
seem to want it to mean "a generic type parameter of dependent member
type", which corresponds to what is effectively a type parameter in
the language, while others want it to mean "contains a type parameter
anywhere in the type". Tease out these two meanings in
isTypeParameter() and hasTypeParameter(), respectively, and sort out
the callers.
Swift SVN r29945
It looks like we were checking in the wrong place, as a result we didn't
catch stuff like
class G<T : AnyObject> {}
_ = G<P>()
This would crash later in IRGen.
Make the conformsToProtocol() check do the right thing, and remove some
other miscellaneous diagnostics in the process. Also, make the
"type 'T' does not conform to protocol 'P'" diagnostic a bit more
detailed.
Unfortunately in a few instances we lose a more descriptive diagnostic to
a general 'cannot invoke 'foo' with argument list of type 'T'' error. The
argument matching diagnostics need to be addressed anyway though.
Fixes <rdar://problem/20311619>.
Swift SVN r29737
Rename existentialConformsToSelf() to existentialTypeSupported(). This
predicate is the "protocol has no Self or associated type requirements"
check, which is a looser condition than self-conformance. This was being
tested to see if the user could refer to the protocol via an existential
type.
The new existentialConformsToSelf() now checks for protocol being @objc,
and for the absence of static methods. This is used as part of the
argument type matching logic in matchType() to determine if the
existential can be bound to a generic type parameter.
The latter condition is stricter, for two reasons:
1) We allow binding existentials to multiple type parameters all sharing
the same generic type parameter T, so we don't want the user to be
able to see any static methods on T.
2) There is an IRGen limitation whereby only existentials without witness
tables can be passed in this manner.
Using the above, the representsNonTrivialGenericParameter() function
has been renamed to canBindGenericParamToExistential(). It now allows
an existential type to be bound to a generic type parameter only under
the following circumstances:
A) If the generic type parameter has no conformances, the match is allowed.
B) If the generic type parameter has at least one conformance, then all
of the conformances on the generic type parameter must be
existentialConformsToSelf() (condition 1 above), and all conformances
on the existential must be @objc (condition 2 above).
Fixes <rdar://problem/18378390> and <rdar://problem/18683843>, and lays
the groundwork for fixing a few other related issues.
Swift SVN r29337
This is a hack.
We currently don't put anything in Clang submodules; they're just wrappers
to track what is and isn't visible. All lookups happen through the top-
level module.
This commit adds a new API getImportedModulesForLookup, which is ONLY used
by top-level name lookup and forAllVisibleModules. It is identical to
getImportedModules for everything but ClangModuleUnits, which instead
compute and cache a list of their transitively imported top-level modules.
This speeds up building Foundation.swiftmodule with a release compiler by
a bit more than 5%, and makes a previously lookup-bound test case compile
a third faster than before.
This is a hack.
rdar://problem/20813240
Swift SVN r28598
Modules occupy a weird space in the AST now: they can be treated like
types (Swift.Int), which is captured by ModuleType. They can be
treated like values for disambiguation (Swift.print), which is
captured by ModuleExpr. And we jump through hoops in various places to
store "either a module or a decl".
Start cleaning this up by transforming Module into ModuleDecl, a
TypeDecl that's implicitly created to describe a module. Subsequent
changes will start folding away the special cases (ModuleExpr ->
DeclRefExpr, name lookup results stop having a separate Module case,
etc.).
Note that the Module -> ModuleDecl typedef is there to limit the
changes needed. Much of this patch is actually dealing with the fact
that Module used to have Ctx and Name public members that now need to
be accessed via getASTContext() and getName(), respectively.
Swift SVN r28284
Replace the 'ignoreMissing' boolean flag with a new option set type,
SubstOptions, which is easier to extend. It is not an OptionSet<>
because a follow-on commit will introduce a non-trivial option that
will require more storage.
Also eliminate the LazyResolver parameter, which is no longer
needed. Eliminate the silly TypeChecker::substType(), whose only
purpose was to provide the resolver.
Swift SVN r27656
This eliminates nonsensical recursion when working with protocol
conformances, and makes their checking more lazy. Start to improve
name lookup to deal with protocol witnesses more lazily, generalizing
the solution we had to all protocol conformances and making it more
directed. We're not done here, as the FIXMEs in the code completion
test imply: this replace-the-requirement-with-the-witness behavior
needs to be sunk down into the AST level so it also applies to
unqualified lookup, visible-decl lookup, etc.
Swift SVN r27639
LLDB asked for this to differentiate between modules loaded successfully and
modules that are correctly found but can't be loaded for some reason.
rdar://problem/19750055
Swift SVN r27041
getImportedModules is the canonical way to get imports, whether private,
public, or both. This is especially true now that we have more flags
for SourceFile imports that really shouldn't be consumed by anyone
outside of SourceFile.
In this same vein, provide addImports instead of setImports, since imports
are always additive.
No visible functionality change.
Swift SVN r26634
We can now use internal declarations safely and correctly in source files!
The remaining work is to make sure testable imports work reliably through
modules, which is important for debugging unit tests.
It's also possible this work will affect compile time, but for the most
part we don't have large quantities of internal declarations that are
being ignored, and some day we will strip them out of non-testable modules
altogether.
Part of rdar://problem/17732115
Swift SVN r26633
Currently a no-op, but effective access for entities within the current
module will soon need to take testability into account. This declaration:
internal func foo() {}
has a formal access of 'internal', but an effective access of 'public' if
we're in a testable mode.
Part of rdar://problem/17732115 (testability)
Swift SVN r26472
Replace the loop over all known protocols with a query into the
actual conformance lookup table, which more properly deals with
out-of-order conformance queries, inheritance of protocol
conformances, and conformance queries in multi-file situtations.
The SILGen test change is because we're no longer emitting redundant
conformances, while the slight diagnostic regression in
circular-inheritance cases is because we handle circular inheritance
very poorly throughout the compiler.
While not the end, this is a major step toward finishing
rdar://problem/18448811.
Swift SVN r26299
This flag indicates that internal APIs within the module should be made
available to client code for testing purposes. Currently does nothing.
Not ready for developer consumption yet, ergo a hidden frontend-only flag.
Part of testability (rdar://problem/17732115)
Swift SVN r26292
Previously, we would require the type checker to be able to build a
conformance, which meant we would actually have to lie in the AST
about having a conformance (or crash; we did the form). Now, we can
form the conformance in the AST and it will be checked in the type
checker when needed. The intent here is to push conformance creation
into the conformance lookup table.
To get here, we had to stop relying on the broken, awful,
ASTContext-wide conformance "cache". A proper cache can come back once
the model is sorted out.
Swift SVN r26250
Instead of relying on Sema to set the existential-conforms-to-self bit, compute it lazily in the AST. This is far cleaner and more dependable than the previous solution.
Swift SVN r26225
