A request is intended to be a pure function of its inputs. That function could, in theory, fail. In practice, there were basically no requests taking advantage of this ability - the few that were using it to explicitly detect cycles can just return reasonable defaults instead of forwarding the error on up the stack.
This is because cycles are checked by *the Evaluator*, and are unwound by the Evaluator.
Therefore, restore the idea that the evaluate functions are themselves pure, but keep the idea that *evaluation* of those requests may fail. This model enables the best of both worlds: we not only keep the evaluator flexible enough to handle future use cases like cancellation and diagnostic invalidation, but also request-based dependencies using the values computed at the evaluation points. These aforementioned use cases would use the llvm::Expected interface and the regular evaluation-point interface respectively.
Previously we had a request for this in
IDETypeChecking, but this wasn't used for queries
made from Sema. Move the request into Sema, and
move `hasDynamicMemberLookupAttribute` onto
TypeBase.
- No need to hash input values first
- Pass many values to a single hash_combine to save on intermediates
- Use hash_combine_range instead of a loop of hash_combines
No functionality change.
Use the delayed parsing of function bodies for source imports, and
switch source imports over to lazy type checking. There's no point in
doing a full type check for them.
Begin refactoring the request evaluator by swapping SWIFT_TYPEID for
SWIFT_REQUEST. Introduce the Zone of the request as a formal parameter
to the macro, then re-expand the request macro to get the type info
back.
SWIFT_REQUEST will eventually grow to encompass more information about
requests as we seek to reduce the boilerplate involved in their
definitions.
We used to have a function getRootAndResultTypeOfKeypathDynamicMember to return
both the root and result type of a subscript. This patch splits the function
into two functions returning root type and result type respectively. It also refactors
the implementation into the evaluator model.
IDE functionality needs some internal type checking logics, e.g. checking
whether an extension is applicable to a concrete type. We used to directly
expose an header from sema called IDETypeChecking.h so that IDE functionalities
could invoke these APIs. The goal of the commit and following commits is to
expose evaluator requests instead of directly exposing function entry points from
sema so that we could later move IDETypeChecking.h to libIDE and implement these functions
by internally evaluating these requests.
```swift
protocol Proto {}
struct ConcreteProto {}
struct MyStruct<T> {}
extension MyStruct where T: Proto {
static var option: MyStruct<ConcreteProto> { get }
}
func foo<T: Proto>(arg: MyStruct<T>) {}
func test() {
foo(arg: .#^HERE^#)
}
```
In this case, the type of `MyStruct.option` is `MyStruct<ConcreteProto>`
whereas the context type is `MyStruct<T> where T: Proto`.
When checking the convertibility of them , we need to "open archetype types".
rdar://problem/24570603
rdar://problem/51723460
This utility was defined in Sema, used in Sema and Index, declared in
two headers, and semi- copy-pasted into SILGen. Pull it into
VarDecl::isMemberwiseInitialized() and use it consistently.
Looks into the root type of the keypath to find additional members. This
does not currently map the type of the completion to the subscript's
return type.
rdar://49029126
The use of the reference to a private implementation caused a silent
use-after-free which would normally not trigger a problem as the use was
pretty close by. The reference would copy the pointer and the
destructor for the implementation would free the backing memory. We
would then continue to use the free'd memory to query the information.
The Windows heap allocator kindly scribbles over the memory which caused
an invalid memory access, helping isolate the use-after-free.
Instead of building ArgumentShuffleExprs, lets just build a TupleExpr,
with explicit representation of collected varargs and default
arguments.
This isn't quite as elegant as it should be, because when re-typechecking,
SanitizeExpr needs to restore the 'old' parameter list by stripping out
the nodes inserted by type checking. However that hackery is all isolated
in one place and will go away soon.
Note that there's a minor change the generated SIL. Caller default
arguments (#file, #line, etc) are no longer delayed and are instead
evaluated in their usual argument position. I don't believe this actually
results in an observable change in behavior, but if it turns out to be
a problem, we can pretty easily change it back to the old behavior with a
bit of extra work.
The client usually cares about a subset of all expressions. A way to differentiate
them is by the protocols these expressions' types conform to. This patch allows
the request to add a list of protocol USRs so that the response only includes those
interested expressions that conform to any of the input protocols.
We also add a field to the response for each expression type to indicate the
conforming protocols names that were originally in the input list.
When an empty list of protocol USRs are given, we report all expressions' types
in the file like the old behavior.
rdar://35199889
This is libIDE side implementation for collecting all type information in a source
file. When several expression share the same source range, we always report the
type of the outermost expression.
rdar://35199889
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
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
It is possible for the SIL optimizers, IRGen, etc. to request information
from the AST that only the type checker can provide, but the type checker
is typically torn down after the “type checking” phase. This can lead to
various crashes late in the compilation cycle.
Keep the type checker instance around as long as the ASTContext is alive
or until someone asks for it to be destroyed.
Fixes SR-285 / rdar://problem/23677338.
Using dummy UnresolvedMemberExpr doesn't give us much benefit. Instead, use
CodeCompletionExpr which is type checked as type variable so can use
CodeCompletionTypeContextAnalyzer to infer context types.
This way, we can eliminate most of special logic for UnresolvedMember.
rdar://problem/39098974
Sink the type checker request classes into the AST library, so that
various functions in the AST library can form type-checking requests.
The actual evaluator functions for these requests continue to live
in the Sema library, called via indirection through the function
pointer tables registered with the request-evaluator.
