In postfix completion, for operator completion, we do:
1. Type check the operand without applying it, but set the resolved
type to the root of the expression.
2. For each possible operators:
i. Build temporary binary/postfix expression
ii. Perform type checking to see whether the operator is applicable
This could be very slow especially if the operand is complex.
* Introduce `ReusePrecheckedType` option to constraint system. With
this option, CSGen respects pre-stored types in expressions and doesn't
take its sub-expressions into account.
* Improve type checking performance because type variables aren't
generated for sub-expressions of LHS (45511835)
* Guarantee that the operand is not modified by the type checker because
expression walkers in `CSGen` doesn't walk into the operand.
* Introduce `TypeChecker::findLHS()` to find LHS for a infix operator from
pre-folded expression. We used to `foldSequence()` temporary
`SequenceExpr` and find 'CodeCompletionExpr' for each attempt.
* No need to flatten folded expression after initial type-checking.
* Save memory of temporary `BinaryExpr` which used to be allocated by
`foldSequence()`.
* Improve accuracy of the completion. `foldSequence()` recovers invalid
combination of operators by `left` associative manner (with
diagnostics). This used to cause false-positive results. For instance,
`a == b <HERE>` used to suggest `==` operator. `findLHS()` returns
`nullptr` for such invalid combination.
rdar://problem/45511835
https://bugs.swift.org/browse/SR-9061
We try to work more-or-less bottom up in the expression when we
attempt apply disjunctions first. This is very helpful to get good
results with designated types enabled in the solver. Rather than
forcing tests to specify both `-swift-version 5` (which also enables
this bottom-up behavior) and enabling designated types, allow them to
just enable the later to get the behavior.
We'll eventually have to revisit this when we decide the specific
conditions that we'll enable the use of designated types under.
We want removing a property override to be a resilient change, so
keypaths should not reference them, preferring to reference the
base declaration instead.
Instead of passing in a DeclContext, which we don't have when emitting a keypath
accessor, pass in a ModuleDecl and ResilienceExpansion.
Keypaths now work well enough in inlinable contexts that we can check in an
end-to-end resilience test.
We now have plenty of extra inhabitants in the variant enum, so we can get rid of the 7-bit hack.
It’d also be possible now to increase small string capacity to a spacious 11 bytes; however this needs a full overhaul of the 32-bit representation, so it needs a little bit more time in the oven.
Also add overloads for these operators to an extension of Array.
This allows us to typecheck array concatenation quickly with
designated type support enabled and the remaining type checker hacks
disabled.
This allows us to skip attempting actual conversions.
This speeds up one of our slow test cases, and perturbs the output of
another test. In the latter case, we stop emitting conversions as part
of the non-semantic piece of the array_expr. The fact that we're not
putting conversions in on that path is something I've seen before in
other instances. I'll open a bug if I cannot find one for it, although
I believe it's entirely cosmetic in this case since we don't rely on
the conversion being there.
This allows us to skip attempting actual conversions.
This speeds up one of our slow test cases, and perturbs the output of
another test. In the latter case, we stop emitting conversions as part
of the non-semantic piece of the array_expr. The fact that we're not
putting conversions in on that path is something I've seen before in
other instances. I'll open a bug if I cannot find one for it, although
I believe it's entirely cosmetic in this case since we don't rely on
the conversion being there.
A resilient change should not *remove* previously-public symbols.
Note that currently, the test_superclass_properties test does not
meet this critierion, because we always emit keypath property
descriptors, even when the property is an override. Fixing this
is a larger change that I'll address in a follow-on PR, so for now
I'm just going to disable the symbol check for this one test only.
Part of <rdar://problem/40432647>.
Previously, they would forward their unused spare bits to be used by other multi-payload enums, but
did not implement anything for single-payload extra inhabitants.
The standard library never ended up needing the low extra inhabitants (<4G on 64-bit Darwin,
<4K elsewhere), so BridgeObject can have the same set of extra inhabitants as the other refcounted
types, allowing `String?????` and `Array??????????` to still use optimized representations.
rdar://problem/45881464
Let's keep track of type mismatch between type deduced
for the body of the closure vs. what is requested
contextually, it makes it much easier to diagnose
problems like:
```swift
func foo(_: () -> Int) {}
foo { "hello" }
```
Because we can pin-point problematic area of the source
when the rest of the system is consistent.
Resolves: rdar://problem/40537960
