`ArgumentAttribute` points to a particular attribute associated
with one of the arguments e.g. `inout` or its type e.g. `@escaping`.
This is very useful when dealing with argument-to-parameter
failures because it allows to express in the locator kind
of a problem.
Extend the constraint system’s diagnostics with specific handling for
matching an enum element pattern that has a subpattern (i.e., to capture
associated values) against an enum case that does not have any associated
value. This brings diagnostics for the new code path on par with the existing
diagnostics of coercePatternToType.
Generate a complete set of constraints for EnumElement patterns, e.g.,
case let .something(x, y)
Most of the complication here comes from the implicit injection of optionals,
e.g., this case can be matched to an optional of the enum type of which
`something` is a member. To effect this change, introduce a locator for
pattern matching and use it to permit implicit unwrapping during member
lookup without triggering an error.
Note also labels are dropped completely when performing the match,
because labels can be added or removed when pattern matching. Label
conflict are currently diagnosed as part of coercePatternToType, which
suffices so long as overloading cases based on argument labels is not
permitted.
The primary observable change from this commit is in diagnostics: rather
than diagnostics being triggered by `TypeChecker::coercePatternToType`,
diagnostics for matching failures here go through the diagnostics machinery
of the constraint solver. This is currently a regression, because
there are no custom diagnostics for pattern match failures within the
constraint system. This regression will be addressed in a subsequent
commit; for now, leave those tests failing.
Introduce a `ImplicitCallAsFunction` locator path
element to represent an implicit member reference
to `callAsFunction`. Then adjust CSApply a little
to check whether it's finishing an apply for a
callable type, and if so build the implicit member
access.
An awful pattern we use throughout the compiler is to save and restore global flags just for little things. In this case, it was just to turn on some extra options in AST printing for type variables. The kicker is that the ASTDumper doesn't even respect this flag. Add this as a PrintOption and remove the offending save-and-restores.
This doesn't quite get them all: we appear to have productized this pattern in the REPL.
Diagnose ephemeral conversions that are passed to @_nonEphemeral
parameters. Currently, this defaults to a warning with a frontend flag
to upgrade to an error. Hopefully this will become an error by default
in a future language version.
This non-user-facing attribute is used to denote pointer parameters
which do not accept pointers produced from temporary pointer conversions
such as array-to-pointer, string-to-pointer, and in some cases
inout-to-pointer.
By convention, most structs and classes in the Swift compiler include a `dump()` method which prints debugging information. This method is meant to be called only from the debugger, but this means they’re often unused and may be eliminated from optimized binaries. On the other hand, some parts of the compiler call `dump()` methods directly despite them being intended as a pure debugging aid. clang supports attributes which can be used to avoid these problems, but they’re used very inconsistently across the compiler.
This commit adds `SWIFT_DEBUG_DUMP` and `SWIFT_DEBUG_DUMPER(<name>(<params>))` macros to declare `dump()` methods with the appropriate set of attributes and adopts this macro throughout the frontend. It does not pervasively adopt this macro in SILGen, SILOptimizer, or IRGen; these components use `dump()` methods in a different way where they’re frequently called from debugging code. Nor does it adopt it in runtime components like swiftRuntime and swiftReflection, because I’m a bit worried about size.
Despite the large number of files and lines affected, this change is NFC.
"Condition" path element is used to represent a condition expression
associated with `if` expression or ternary operator `? :`.
Locator has been changed in the way that it's now anchored from `if`
itself which simplifies down to condition expression it needed.
This commit replaces the `getValue()` and `getValue2()` members on
`ConstraintLocator::PathElement` with specific accessors for each
expected path component kind. IMO this adds some clarity to the call
sites, especially for `getArgIdx()` and `getParamIdx()`.
In addition, this commit adds a private `getValue` member that can
access a value at a given index, which will make it easier to add a
third value in the future.
Instead of keeping two locators in the fix let's store only the
original locator and simplify it later in process of emitting
a diagnostic. That helps to avoid some duplicate work as well
as makes sure that locators supplied to the diagnostic always
have an anchor.
Resolves: rdar://problem/53344815
We would previously fail to match something like (C<$T1> & P) against
(C<Int> & P) when the constraint kind was <= Subtype, because we would
fall back to a type equality test in that case.
However, this was only valid for protocol compositions without superclass
constraints since the superclass could contain a type variable on one
side of the constraint.
Fix this by adding support for protocol composition types to
matchDeepEqualityTypes().
It's only needed in one place in the constraint solver to allow
`() -> T` to `() -> ()` and `() -> Never` to `() -> T` for expressions
representing return of a single expression functions, so to simplify
contextual type handling in diagnostic and other places it would be
better to replace dedicated locator kind with a flag on existing `ContextualType`.
Resolves: rdar://problem/51641323
KeyPath dynamic member lookup is limited to what key path itself
could do, so let's detect and diagnose invalid references just
like we do for regular key path expressions.
Resolves: rdar://problem/50376224
