Like switch cases, a catch clause may now include a comma-
separated list of patterns. The body will be executed if any
one of those patterns is matched.
This patch replaces `CatchStmt` with `CaseStmt` as the children
of `DoCatchStmt` in the AST. This necessitates a number of changes
throughout the compiler, including:
- Parser & libsyntax support for the new syntax and AST structure
- Typechecking of multi-pattern catches, including those which
contain bindings.
- SILGen support
- Code completion updates
- Profiler updates
- Name lookup changes
When printing the generated interface of a module, also print the decls from
any underscored cross-import overlays it is the direct, or indirect underlying
module of. Declarations are grouped by overlay, with a descriptive `MARK:`
comment introducing each overlay, and a regular comment above each decl listing
the required bystander modules that must be imported for the decl to be
available.
In addition in each overlay:
- import declarations of any underlying modules are filtered out, since they
are either other underscored cross-import overlays, or the target module they
are being presented as being part of.
- import declarations that are also in the target module are filtered out, since
the overlay is being presented as a conditional part of the target module.
Resolves rdar://problem/59445385
When we are printing Swift interface, we have to skip the override keyword
if the overriden decl is invisible from the interface. Otherwise, an error
will occur while building the Swift module because the overriding decl
doesn't override anything.
We couldn't skip every `override` keywords because they change the
ABI if the overriden decl is also publicly visible.
For public-override-internal case, having `override` doesn't have ABI
implication. Thus we can skip them.
rdar://58562780
The design implemented in this patch is that we lower the types of accessors with pattern substitutions when lowering them against a different accessor, which happens with class overrides and protocol witnesses, and that we introduce pattern substitutions when substituting into a non-patterned coroutine type. This seems to achieve consistent abstraction without introduce a ton of new complexity.
An earlier version of this patch tried to define witness thunks (conservatively, just for accessors) by simply applying the requirement substitutions directly to the requirement. Conceptually that should work, but I ran into a lot of trouble with things that assumed that pattern substitutions didn't conceal significant substitution work. for example, resolving a dependent member in a component type could find a new use of an opaque archetype when the code assumed that such types had already been substituted away. So while I think that is definiteely a promising direction, I had to back that out in order to make the number of changes manageable for a single PR.
As part of this, I had to fix a number of little bugs here and there, some of which I just introduced. One of these bugfixes is a place where the substitution code was trying to improperly abstract function types when substituting them in for a type parameter, and it's been in the code for a really long time, and I'm really not sure how it's never blown up before.
I'm increasingly of the opinion that invocation substitutions are not actually necessary, but that --- after we've solved the substitution issues above --- we may want the ability to build multiple levels of pattern substitution so that we can guarantee that e.g. witness thunks always have the exact component structure of the requirement before a certain level of substitution, thus allowing the witness substitutions to be easily extracted.
In order to allow this, I've had to rework the syntax of substituted function types; what was previously spelled `<T> in () -> T for <X>` is now spelled `@substituted <T> () -> T for <X>`. I think this is a nice improvement for readability, but it did require me to churn a lot of test cases.
Distinguishing the substitutions has two chief advantages over the existing representation. First, the semantics seem quite a bit clearer at use points; the `implicit` bit was very subtle and not always obvious how to use. More importantly, it allows the expression of generic function types that must satisfy a particular generic abstraction pattern, which was otherwise impossible to express.
As an example of the latter, consider the following protocol conformance:
```
protocol P { func foo() }
struct A<T> : P { func foo() {} }
```
The lowered signature of `P.foo` is `<Self: P> (@in_guaranteed Self) -> ()`. Without this change, the lowered signature of `A.foo`'s witness would be `<T> (@in_guaranteed A<T>) -> ()`, which does not preserve information about the conformance substitution in any useful way. With this change, the lowered signature of this witness could be `<T> @substituted <Self: P> (@in_guaranteed Self) -> () for <A<T>>`, which nicely preserves the exact substitutions which relate the witness to the requirement.
When we adopt this, it will both obviate the need for the special witness-table conformance field in SILFunctionType and make it far simpler for the SILOptimizer to devirtualize witness methods. This patch does not actually take that step, however; it merely makes it possible to do so.
As another piece of unfinished business, while `SILFunctionType::substGenericArgs()` conceptually ought to simply set the given substitutions as the invocation substitutions, that would disturb a number of places that expect that method to produce an unsubstituted type. This patch only set invocation arguments when the generic type is a substituted type, which we currently never produce in type-lowering.
My plan is to start by producing substituted function types for accessors. Accessors are an important case because the coroutine continuation function is essentially an implicit component of the function type which the current substitution rules simply erase the intended abstraction of. They're also used in narrower ways that should exercise less of the optimizer.
The `@noDerivative` attribute marks the non-differentiability parameters of a
`@differentiable` function type. All parameters except those marked with
`@noDerivative` are differentiability parameters.
For example, `@differentiable (Float, @noDerivative Float) -> Float` is only
differentiable with respect to its first parameter.
The `@noDerivative` attribute is represented as a
`SILParameterDifferentiability` bit on `SILParameterInfo`.
Add round-trip serialization tests.
Resolves TF-872.
Adds a tool `swift-symbolgraph-extract` that reads an existing Swift
module and prints a platform- and language-agnostic JSON description of
the module, primarly for documentation.
Adds a small sub-library `SymbolGraphGen` which houses the core
implementation for collecting relevant information about declarations.
The main entry point is integrated directly into the driver as a mode:
the tool is meant to be run outside of the normal edit-compile-run/test
workflow to avoid impacting build times.
Along with common options for other tools, unique options include
`pretty-print` for debugging, and a `minimum-access-level` options for
including internal documentation.
A symbol graph is a directed graph where the nodes are symbols in a
module and the edges are relationships between them. For example, a
`struct S` may have a member `var x`. The graph would have two nodes for
`S` and `x`, and one "member-of" relationship edge. Other relationship
kinds include "inherits-from" or "conforms to". The data format for a
symbol graph is still under development and may change without notice
until a specificiation and versioning scheme is published.
Various aspects about a symbol are recorded in the nodes, such as
availability, documentation comments, or data needed for printing the
shapes of declarations without having to understand specifics about the
langauge.
Implicit and public-underscored stdlib declarations are not included by
default.
rdar://problem/55346798
instead of AssociatedTypeDecl::getInherited() when checking if the
return type should be suggested as "opaque result type" in override
completion.
AssociatedTypeDecl::getInherited() is not serialized. So if the protocol
is declared in a module, it was never suggested as 'some' result.
rdar://problem/57245073
This reverts commit e805fe486e, which reverted
the change earlier. The problem was caused due to a simultaneous change to some
code by the PR with parsing and printing for Clang function types (#28737)
and the PR which introduced Located<T> (#28643).
This commit also includes a small change to make sure the intersecting region
is fixed: the change is limited to using the fields of Located<T> in the
`tryParseClangType` lambda.
This type wraps a DeclName, indicating that it is a reference to a declaration that exists somewhere else and it requires slightly “fuzzy” comparison (i.e. if it’s not compound, only the base names should be compared). DeclName::matchesRef() and MemberLookupTable::find() both now take a DeclNameRef instead of a DeclName.
This commit temporarily allows implicit conversion from DeclName; I’ll flip the switch on that in a later commit.
Replaces `ComponentIdentTypeRepr::getIdentifier()` and `getIdLoc()` with `getNameRef()` and `getNameLoc()`, which use `DeclName` and `DeclNameRef` respectively.
Previously, we would print
```swift
public private(set) var x: Int
```
as
```swift
@_hasStorage public var x: Swift.Int {
get
}
```
which is a) incorrectly indented, and b) shouldn't have newlines in part
of the Generated Interface.
Fixes [SR-9816](https://bugs.swift.org/browse/SR-9816)
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.
This commit introduces a request to type-check a
default argument expression and splits
`getDefaultValue` into 2 accessors:
- `getStructuralDefaultExpr` which retrieves the
potentially un-type-checked default argument
expression.
- `getTypeCheckedDefaultExpr` which retrieves a
fully type-checked default argument expression.
In addition, this commit adds `hasDefaultExpr`,
which allows checking for a default expr without
kicking off a request.
