Although I don't plan to bring over new assertions wholesale
into the current qualification branch, it's entirely possible
that various minor changes in main will use the new assertions;
having this basic support in the release branch will simplify that.
(This is why I'm adding the includes as a separate pass from
rewriting the individual assertions)
If an expression refers to noncopyable storage, then default to performing
a borrowing switch, where `let` bindings in patterns borrow out of the
matched value. If an expression refers to a temporary value or explicitly
uses the `consume` keyword, then perform a consuming switch, where
`let` bindings take ownership of corresponding parts of the matched value.
Allow `_borrowing` to still be used to explicitly bind a pattern variable
as a borrow, with no-implicit-copy semantics for copyable values.
A `let` binding of a copyable subpattern can create an independent variable
which should be copyable and consumable without affecting a borrowed
move-only base. In the same way that `borrowing` parameters are
no-implicit-copy, though, explicitly `_borrowing` subpatterns of
copyable type should be no-implicit-copy as well.
When matching against a noncopyable value, whether the match operation can
borrow the value in-place or needs to take ownership of it is significant.
This can generally be determined from the kind of pattern being used, except
in the case of expr patterns, where it depends on type-checking the `~=`
operator that was used.
This is phase-1 of switching from llvm::Optional to std::optional in the
next rebranch. llvm::Optional was removed from upstream LLVM, so we need
to migrate off rather soon. On Darwin, std::optional, and llvm::Optional
have the same layout, so we don't need to be as concerned about ABI
beyond the name mangling. `llvm::Optional` is only returned from one
function in
```
getStandardTypeSubst(StringRef TypeName,
bool allowConcurrencyManglings);
```
It's the return value, so it should not impact the mangling of the
function, and the layout is the same as `std::optional`, so it should be
mostly okay. This function doesn't appear to have users, and the ABI was
already broken 2 years ago for concurrency and no one seemed to notice
so this should be "okay".
I'm doing the migration incrementally so that folks working on main can
cherry-pick back to the release/5.9 branch. Once 5.9 is done and locked
away, then we can go through and finish the replacement. Since `None`
and `Optional` show up in contexts where they are not `llvm::None` and
`llvm::Optional`, I'm preparing the work now by going through and
removing the namespace unwrapping and making the `llvm` namespace
explicit. This should make it fairly mechanical to go through and
replace llvm::Optional with std::optional, and llvm::None with
std::nullopt. It's also a change that can be brought onto the
release/5.9 with minimal impact. This should be an NFC change.
This replaces `synthesizeTildeEqualsOperatorApplication`,
and synthesizes the match expression and var
on-demand.
Additionally, it pushes the lookup logic into
pre-checking.
Provide ASTWalker with a customization point to specify whether to
check macro arguments (which are type checked but never emitted), the
macro expansion (which is the result of applying the macro and is
actually emitted into the source), or both. Provide answers for the
~115 different ASTWalker visitors throughout the code base.
Fixes rdar://104042945, which concerns checking of effects in
macro arguments---which we shouldn't do.
Rather than having Sema set the same Optional
some decl, let's just store a pointer to the
ASTContext and retrieve it on demand.
Additionally, add `create` and `createImplicit`
factory methods.
Replace the use of bool and pointer returns for
`walkToXXXPre`/`walkToXXXPost`, and instead use
explicit actions such as `Action::Continue(E)`,
`Action::SkipChildren(E)`, and `Action::Stop()`.
There are also conditional variants, e.g
`Action::SkipChildrenIf`, `Action::VisitChildrenIf`,
and `Action::StopIf`.
There is still more work that can be done here, in
particular:
- SourceEntityWalker still needs to be migrated.
- Some uses of `return false` in pre-visitation
methods can likely now be replaced by
`Action::Stop`.
- We still use bool and pointer returns internally
within the ASTWalker traversal, which could likely
be improved.
But I'm leaving those as future work for now as
this patch is already large enough.
These will never appear in the source language, but can arise
after substitution when the original type is a tuple type with
a pack expansion type.
Two examples:
- original type: (Int, T...), substitution T := {}
- original type: (T...), substitution T := {Int}
We need to model these correctly to maintain invariants.
Callers that previously used to rely on TupleType::get()
returning a ParenType now explicitly check for the one-element
case instead.
Many, many, many types in the Swift compiler are intended to only be allocated in the ASTContext. We have previously implemented this by writing several `operator new` and `operator delete` implementations into these types. Factor those out into a new base class instead.
LLVM, as of 77e0e9e17daf0865620abcd41f692ab0642367c4, now builds with
-Wsuggest-override. Let's clean up the swift sources rather than disable
the warning locally.
VarPattern is today used to implement both 'let' and 'var' pattern bindings, so
today is already misleading. The reason why the name Var was chosen was done b/c
it is meant to represent a pattern that performs 'variable binding'. Given that
I am going to add a new 'inout' pattern binding to this, it makes sense to
give it now a better fitting name before I make things more confusing.
Property wrappers are allowed to infer the type of a variable, but this
only worked when the property wrapper was provided with an explicit
initialization, e.g.,
@WrapsAnInt() var x // infers type Int from WrapsAnInt.wrappedValue
However, when default initialization is supported by the property wrapper,
dropping the parentheses would produce an error about the missing type
annotation
@WrapsAnInt var x
Make this second case behave like the first, so that default initialization
works consistently with the explicitly-specified version.
Fixes rdar://problem/59471019.
Contextual pattern describes a particular pattern with enough
contextual information to determine its type. Use this to simplify
TypeChecker::typeCheckPattern()'s interface in a manner that will
admit request'ification.
We've been running doxygen with the autobrief option for a couple of
years now. This makes the \brief markers into our comments
redundant. Since they are a visual distraction and we don't want to
encourage more \brief markers in new code either, this patch removes
them all.
Patch produced by
for i in $(git grep -l '\\brief'); do perl -pi -e 's/\\brief //g' $i & done
* [AST] Remove stored TypeLoc from TypedPattern
TypedPattern was only using this TypeLoc as a means to a TypeRepr, which
caused it to store the pattern type twice (through the superclass and through
the TypeLoc itself.)
This also fixes a bug where deserializing a TypedPattern doesn't store
the type correctly and generally cleans up TypedPattern initialization.
Resolves rdar://44144435
* Address review comments
Inline bitfields are a common design pattern in LLVM and derived
projects, but the associated boilerplate can be demotivating and
brittle. This new header makes it easier to define and use inline
bitfields in Swift.
This also reorders some fields for better code generation.
WalkToVarDecls should only walk within the current pattern, not into
any other nodes (especially not nodes that open a scope.)
Restricting this fixes the name lookup weirdness that caused the crash.
A lot of files transitively include Expr.h, because it was
included from SILInstruction.h, SILLocation.h and SILDeclRef.h.
However in reality most of these files don't do anything
with Exprs, especially not anything in IRGen or the SILOptimizer.
Now we're down to 171 files in the frontend which depend on
Expr.h, which is still a lot but much better than before.
In Swift 4 mode, no longer consider e.g. 'nsNumber as Int' or 'nsValue as NSRange' to be valid coercions. This would break compatibility with Swift 3, so in Swift 3 mode, accept the coercion, but *also* accept a checked cast without a warning, and raise a migration warning about the unchecked coercion.
Previously, bridging conversions were handled as a form of "explicit
conversion" that was treated along the same path as normal
conversions in matchTypes(). Historically, this made some
sense---bridging was just another form of conversion---however, Swift
now separates out bridging into a different kind of conversion that is
available only via an explicit "as". This change accomplishes a few
things:
* Improves type inference around "as" coercions. We were incorrectly
inferring type variables of the "x" in "x as T" in cases where a
bridging conversion was expected, which cause some type inference
failures (e.g., the SR-3319 regression).
* Detangles checking for bridging conversions from other conversions,
so it's easier to isolate when we're applying a bridging
conversion.
* Explicitly handle optionals when dealing with bridging conversions,
addressing a number of problems with incorrect diagnostics, e.g.,
complains about "unrelated type" cast failures that would succeed at
runtime.
Addresses rdar://problem/29496775 / SR-3319 / SR-2365.
- 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.
The ASTContext-level map of delayed pattern contexts is a DenseMap
that could get reallocated by lazy deserialization of generic
environments. Don't re-use an iterator across the potential lazy
deserialization.
When a pattern within a type context is serialized, serialize its
interface type (not its contextual type). When deserializing, record
the interface type and keep a side table of the associated
DeclContext, so that we can lazily map to the contextual type on first
access. This is designed to break recursion when we change the way
archetypes and generic environments are serialized.
