mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
2912159776
These changes make the following improvements to how we generate diagnostics for expression typecheck failure:
- Customizing a diagnostic for a specific expression kind is as easy as adding a new method to the FailureDiagnosis class,
and does not require intimate knowledge of the constraint solver’s inner workings.
- As part of this patch, I’ve introduced specialized diagnostics for call, binop, unop, subscript, assignment and inout
expressions, but we can go pretty far with this.
- This also opens up the possibility to customize diagnostics not just for the expression kind, but for the specific types
involved as well.
- For the purpose of presenting accurate type info, partially-specialized subexpressions are individually re-typechecked
free of any contextual types. This allows us to:
- Properly surface subexpression errors.
- Almost completely avoid any type variables in our diagnostics. In cases where they could not be eliminated, we now
substitute in "_".
- More accurately indicate the sources of errors.
- We do a much better job of diagnosing disjunction failures. (So no more nonsensical ‘UInt8’ error messages.)
- We now present reasonable error messages for overload resolution failures, informing the user of partially-matching
parameter lists when possible.
At the very least, these changes address the following bugs:
<rdar://problem/15863738> More information needed in type-checking error messages
<rdar://problem/16306600> QoI: passing a 'let' value as an inout results in an unfriendly diagnostic
<rdar://problem/16449805> Wrong error for struct-to-protocol downcast
<rdar://problem/16699932> improve type checker diagnostic when passing Double to function taking a Float
<rdar://problem/16707914> fatal error: Can't unwrap Optional.None…Optional.swift, line 75 running Master-Detail Swift app built from template
<rdar://problem/16785829> Inout parameter fixit
<rdar://problem/16900438> We shouldn't leak the internal type placeholder
<rdar://problem/16909379> confusing type check diagnostics
<rdar://problem/16951521> Extra arguments to functions result in an unhelpful error
<rdar://problem/16971025> Two Terrible Diagnostics
<rdar://problem/17007804> $T2 in compiler error string
<rdar://problem/17027483> Terrible diagnostic
<rdar://problem/17083239> Mysterious error using find() with Foundation types
<rdar://problem/17149771> Diagnostic for closure with no inferred return value leaks type variables
<rdar://problem/17212371> Swift poorly-worded error message when overload resolution fails on return type
<rdar://problem/17236976> QoI: Swift error for incorrectly typed parameter is confusing/misleading
<rdar://problem/17304200> Wrong error for non-self-conforming protocols
<rdar://problem/17321369> better error message for inout protocols
<rdar://problem/17539380> Swift error seems wrong
<rdar://problem/17559593> Bogus locationless "treating a forced downcast to 'NSData' as optional will never produce 'nil'" warning
<rdar://problem/17567973> 32-bit error message is really far from the mark: error: missing argument for parameter 'withFont' in call
<rdar://problem/17671058> Wrong error message: "Missing argument for parameter 'completion' in call"
<rdar://problem/17704609> Float is not convertible to UInt8
<rdar://problem/17705424> Poor error reporting for passing Doubles to NSColor: extra argument 'red' in call
<rdar://problem/17743603> Swift compiler gives misleading error message in "NSLayoutConstraint.constraintsWithVisualFormat("x", options: 123, metrics: nil, views: views)"
<rdar://problem/17784167> application of operator to generic type results in odd diagnostic
<rdar://problem/17801696> Awful diagnostic trying to construct an Int when .Int is around
<rdar://problem/17863882> cannot convert the expression's type '()' to type 'Seq'
<rdar://problem/17865869> "has different argument names" diagnostic when parameter defaulted-ness differs
<rdar://problem/17937593> Unclear error message for empty array literal without type context
<rdar://problem/17943023> QoI: compiler displays wrong error when a float is provided to a Int16 parameter in init method
<rdar://problem/17951148> Improve error messages for expressions inside if statements by pre-evaluating outside the 'if'
<rdar://problem/18057815> Unhelpful Swift error message
<rdar://problem/18077468> Incorrect argument label for insertSubview(...)
<rdar://problem/18079213> 'T1' is not identical to 'T2' lacks directionality
<rdar://problem/18086470> Confusing Swift error message: error: 'T' is not convertible to 'MirrorDisposition'
<rdar://problem/18098995> QoI: Unhelpful compiler error when leaving off an & on an inout parameter
<rdar://problem/18104379> Terrible error message
<rdar://problem/18121897> unexpected low-level error on assignment to immutable value through array writeback
<rdar://problem/18123596> unexpected error on self. capture inside class method
<rdar://problem/18152074> QoI: Improve diagnostic for type mismatch in dictionary subscripting
<rdar://problem/18242160> There could be a better error message when using [] instead of [:]
<rdar://problem/18242812> 6A1021a : Type variable leaked
<rdar://problem/18331819> Unclear error message when trying to set an element of an array constant (Swift)
<rdar://problem/18414834> Bad diagnostics example
<rdar://problem/18422468> Calculation of constant value yields unexplainable error
<rdar://problem/18427217> Misleading error message makes debugging difficult
<rdar://problem/18439742> Misleading error: "cannot invoke" mentions completely unrelated types as arguments
<rdar://problem/18535804> Wrong compiler error from swift compiler
<rdar://problem/18567914> Xcode 6.1. GM, Swift, assignment from Int64 to NSNumber. Warning shown as problem with UInt8
<rdar://problem/18784027> Negating Int? Yields Float
<rdar://problem/17691565> attempt to modify a 'let' variable with ++ results in typecheck error about @lvalue Float
<rdar://problem/17164001> "++" on let value could give a better error message
Swift SVN r23782
2183 lines
70 KiB
C++
2183 lines
70 KiB
C++
//===--- CSDiag.cpp - Constraint Diagnostics ------------------------------===//
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//
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// This source file is part of the Swift.org open source project
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//
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// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
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// Licensed under Apache License v2.0 with Runtime Library Exception
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//
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// See http://swift.org/LICENSE.txt for license information
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// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements diagnostics for the type checker.
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//
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//===----------------------------------------------------------------------===//
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#include "ConstraintSystem.h"
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using namespace swift;
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using namespace constraints;
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void Failure::dump(SourceManager *sm) const {
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dump(sm, llvm::errs());
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}
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void Failure::dump(SourceManager *sm, raw_ostream &out) const {
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out << "(";
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if (locator) {
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out << "@";
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locator->dump(sm, out);
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out << ": ";
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}
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switch (getKind()) {
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case DoesNotConformToProtocol:
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out << getFirstType().getString() << " does not conform to "
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<< getSecondType().getString();
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break;
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case DoesNotHaveMember:
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out << getFirstType().getString() << " does not have a member named '"
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<< getName() << "'";
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break;
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case DoesNotHaveNonMutatingMember:
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out << " immutable value of type " << getFirstType().getString()
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<< " only has mutating members named '"
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<< getName() << "'";
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break;
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case FunctionTypesMismatch:
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out << "function type " << getFirstType().getString() << " is not equal to "
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<< getSecondType().getString();
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break;
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case FunctionAutoclosureMismatch:
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out << "autoclosure mismatch " << getFirstType().getString() << " vs. "
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<< getSecondType().getString();
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break;
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case FunctionNoReturnMismatch:
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out << "noreturn attribute mismatch " << getFirstType().getString()
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<< " vs. " << getSecondType().getString();
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break;
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case IsNotMetatype:
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out << getFirstType().getString() << " is not a metatype";
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break;
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case IsNotArchetype:
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out << getFirstType().getString() << " is not an archetype";
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break;
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case IsNotClass:
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out << getFirstType().getString() << " is not a class";
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break;
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case IsNotBridgedToObjectiveC:
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out << getFirstType().getString() << "is not bridged to Objective-C";
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break;
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case IsNotDynamicLookup:
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out << getFirstType().getString() << " is not a dynamic lookup value";
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break;
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case IsNotOptional:
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out << getFirstType().getString() << "is not an optional type";
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break;
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case TupleNameMismatch:
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case TupleNamePositionMismatch:
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case TupleSizeMismatch:
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case TupleVariadicMismatch:
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case TupleUnused:
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out << "mismatched tuple types " << getFirstType().getString() << " and "
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<< getSecondType().getString();
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break;
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case TypesNotConstructible:
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out << getFirstType().getString() << " is not a constructible argument for "
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<< getSecondType().getString();
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break;
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case TypesNotConvertible:
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out << getFirstType().getString() << " is not convertible to "
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<< getSecondType().getString();
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break;
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case TypesNotSubtypes:
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out << getFirstType().getString() << " is not a subtype of "
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<< getSecondType().getString();
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break;
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case TypesNotEqual:
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out << getFirstType().getString() << " is not equal to "
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<< getSecondType().getString();
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break;
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case IsForbiddenLValue:
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out << "disallowed l-value binding of " << getFirstType().getString()
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<< " and " << getSecondType().getString();
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break;
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case OutOfOrderArgument:
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out << "out-of-order argument " << getValue() << " should come before "
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<< getSecondValue();
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break;
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case MissingArgument:
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out << "missing argument for parameter " << getValue();
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break;
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case ExtraArgument:
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out << "extra argument " << getValue();
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break;
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case NoPublicInitializers:
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out << getFirstType().getString()
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<< " does not have any public initializers";
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break;
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case UnboundGenericParameter:
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out << getFirstType().getString()
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<< " is an unbound generic parameter";
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break;
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case ExistentialGenericParameter:
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out << getFirstType().getString()
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<< " bound to non-@objc existential type "
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<< getSecondType().getString();
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break;
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}
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out << ")\n";
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}
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/// Given a subpath of an old locator, compute its summary flags.
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static unsigned recomputeSummaryFlags(ConstraintLocator *oldLocator,
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ArrayRef<LocatorPathElt> path) {
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if (oldLocator->getSummaryFlags() != 0)
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return ConstraintLocator::getSummaryFlagsForPath(path);
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return 0;
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}
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ConstraintLocator *
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constraints::simplifyLocator(ConstraintSystem &cs,
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ConstraintLocator *locator,
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SourceRange &range1,
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SourceRange &range2,
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ConstraintLocator **targetLocator) {
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// Clear out the target locator result.
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if (targetLocator)
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*targetLocator = nullptr;
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// The path to be tacked on to the target locator to identify the specific
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// target.
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Expr *targetAnchor;
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SmallVector<LocatorPathElt, 4> targetPath;
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auto path = locator->getPath();
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auto anchor = locator->getAnchor();
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simplifyLocator(anchor, path, targetAnchor, targetPath, range1, range2);
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// If we have a target anchor, build and simplify the target locator.
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if (targetLocator && targetAnchor) {
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SourceRange targetRange1, targetRange2;
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unsigned targetFlags = recomputeSummaryFlags(locator, targetPath);
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*targetLocator = simplifyLocator(cs,
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cs.getConstraintLocator(targetAnchor,
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targetPath,
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targetFlags),
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targetRange1, targetRange2);
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}
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// If we didn't simplify anything, just return the input.
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if (anchor == locator->getAnchor() &&
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path.size() == locator->getPath().size()) {
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return locator;
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}
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// Recompute the summary flags if we had any to begin with. This is
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// necessary because we might remove e.g. tuple elements from the path.
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unsigned summaryFlags = recomputeSummaryFlags(locator, path);
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return cs.getConstraintLocator(anchor, path, summaryFlags);
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}
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void constraints::simplifyLocator(Expr *&anchor,
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ArrayRef<LocatorPathElt> &path,
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Expr *&targetAnchor,
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SmallVectorImpl<LocatorPathElt> &targetPath,
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SourceRange &range1, SourceRange &range2) {
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range1 = SourceRange();
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range2 = SourceRange();
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targetAnchor = nullptr;
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while (!path.empty()) {
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switch (path[0].getKind()) {
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case ConstraintLocator::ApplyArgument:
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// Extract application argument.
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if (auto applyExpr = dyn_cast<ApplyExpr>(anchor)) {
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// The target anchor is the function being called.
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targetAnchor = applyExpr->getFn();
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targetPath.push_back(path[0]);
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anchor = applyExpr->getArg();
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path = path.slice(1);
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continue;
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}
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break;
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case ConstraintLocator::ApplyFunction:
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// Extract application function.
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if (auto applyExpr = dyn_cast<ApplyExpr>(anchor)) {
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// No additional target locator information.
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = applyExpr->getFn();
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path = path.slice(1);
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continue;
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}
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// The unresolved member itself is the function.
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if (auto unresolvedMember = dyn_cast<UnresolvedMemberExpr>(anchor)) {
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if (unresolvedMember->getArgument()) {
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// No additional target locator information.
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = unresolvedMember;
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path = path.slice(1);
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}
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continue;
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}
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break;
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case ConstraintLocator::Load:
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case ConstraintLocator::RvalueAdjustment:
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case ConstraintLocator::ScalarToTuple:
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// Loads, rvalue adjustment, and scalar-to-tuple conversions are implicit.
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path = path.slice(1);
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continue;
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case ConstraintLocator::NamedTupleElement:
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case ConstraintLocator::TupleElement:
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// Extract tuple element.
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if (auto tupleExpr = dyn_cast<TupleExpr>(anchor)) {
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// Append this extraction to the target locator path.
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if (targetAnchor) {
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targetPath.push_back(path[0]);
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}
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anchor = tupleExpr->getElement(path[0].getValue());
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path = path.slice(1);
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continue;
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}
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break;
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case ConstraintLocator::ApplyArgToParam:
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// Extract tuple element.
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if (auto tupleExpr = dyn_cast<TupleExpr>(anchor)) {
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// Append this extraction to the target locator path.
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if (targetAnchor) {
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targetPath.push_back(path[0]);
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}
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anchor = tupleExpr->getElement(path[0].getValue());
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path = path.slice(1);
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continue;
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}
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// Extract subexpression in parentheses.
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if (auto parenExpr = dyn_cast<ParenExpr>(anchor)) {
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assert(path[0].getValue() == 0);
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// Append this extraction to the target locator path.
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if (targetAnchor) {
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targetPath.push_back(path[0]);
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}
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anchor = parenExpr->getSubExpr();
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path = path.slice(1);
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}
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break;
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case ConstraintLocator::Member:
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case ConstraintLocator::MemberRefBase:
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if (auto dotExpr = dyn_cast<UnresolvedDotExpr>(anchor)) {
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// No additional target locator information.
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targetAnchor = nullptr;
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targetPath.clear();
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range1 = dotExpr->getNameLoc();
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anchor = dotExpr->getBase();
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path = path.slice(1);
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continue;
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}
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break;
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case ConstraintLocator::InterpolationArgument:
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if (auto interp = dyn_cast<InterpolatedStringLiteralExpr>(anchor)) {
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// No additional target locator information.
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// FIXME: Dig out the constructor we're trying to call?
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = interp->getSegments()[path[0].getValue()];
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path = path.slice(1);
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continue;
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}
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break;
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case ConstraintLocator::AssignSource:
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if (auto assign = dyn_cast<AssignExpr>(anchor)) {
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targetAnchor = assign->getDest();
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targetPath.clear();
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anchor = assign->getSrc();
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path = path.slice(1);
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continue;
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}
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break;
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case ConstraintLocator::SubscriptIndex:
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if (auto subscript = dyn_cast<SubscriptExpr>(anchor)) {
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targetAnchor = subscript->getBase();
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targetPath.clear();
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anchor = subscript->getIndex();
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path = path.slice(1);
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continue;
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}
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break;
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default:
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// FIXME: Lots of other cases to handle.
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break;
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}
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// If we get here, we couldn't simplify the path further.
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break;
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}
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}
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/// Simplify the given locator down to a specific anchor expression,
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/// if possible.
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///
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/// \returns the anchor expression if it fully describes the locator, or
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/// null otherwise.
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static Expr *simplifyLocatorToAnchor(ConstraintSystem &cs,
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ConstraintLocator *locator) {
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if (!locator || !locator->getAnchor())
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return nullptr;
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SourceRange range1, range2;
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locator = simplifyLocator(cs, locator, range1, range2);
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if (!locator->getAnchor() || !locator->getPath().empty())
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return nullptr;
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return locator->getAnchor();
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}
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/// Retrieve the argument pattern for the given declaration.
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///
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static Pattern *getParameterPattern(ValueDecl *decl) {
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if (auto func = dyn_cast<FuncDecl>(decl))
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return func->getBodyParamPatterns()[0];
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if (auto constructor = dyn_cast<ConstructorDecl>(decl))
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return constructor->getBodyParamPatterns()[1];
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if (auto subscript = dyn_cast<SubscriptDecl>(decl))
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return subscript->getIndices();
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// FIXME: Variables of function type?
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return nullptr;
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}
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ResolvedLocator constraints::resolveLocatorToDecl(
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ConstraintSystem &cs,
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ConstraintLocator *locator,
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std::function<Optional<SelectedOverload>(ConstraintLocator *)> findOvlChoice,
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std::function<ConcreteDeclRef (ValueDecl *decl,
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Type openedType)> getConcreteDeclRef)
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{
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assert(locator && "Null locator");
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if (!locator->getAnchor())
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return ResolvedLocator();
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ConcreteDeclRef declRef;
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auto anchor = locator->getAnchor();
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// Unwrap any specializations, constructor calls, implicit conversions, and
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// '.'s.
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// FIXME: This is brittle.
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do {
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if (auto specialize = dyn_cast<UnresolvedSpecializeExpr>(anchor)) {
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anchor = specialize->getSubExpr();
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continue;
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}
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if (auto implicit = dyn_cast<ImplicitConversionExpr>(anchor)) {
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anchor = implicit->getSubExpr();
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continue;
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}
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if (auto constructor = dyn_cast<ConstructorRefCallExpr>(anchor)) {
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anchor = constructor->getFn();
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continue;
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}
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if (auto dotSyntax = dyn_cast<DotSyntaxBaseIgnoredExpr>(anchor)) {
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anchor = dotSyntax->getRHS();
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continue;
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}
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if (auto dotSyntax = dyn_cast<DotSyntaxCallExpr>(anchor)) {
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anchor = dotSyntax->getFn();
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continue;
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}
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break;
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} while (true);
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auto getConcreteDeclRefFromOverload
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= [&](const SelectedOverload &selected) -> ConcreteDeclRef {
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return getConcreteDeclRef(selected.choice.getDecl(),
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selected.openedType);
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};
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|
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if (auto dre = dyn_cast<DeclRefExpr>(anchor)) {
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// Simple case: direct reference to a declaration.
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declRef = dre->getDeclRef();
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} else if (auto mre = dyn_cast<MemberRefExpr>(anchor)) {
|
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// Simple case: direct reference to a declaration.
|
|
declRef = mre->getMember();
|
|
} else if (isa<OverloadedDeclRefExpr>(anchor) ||
|
|
isa<OverloadedMemberRefExpr>(anchor) ||
|
|
isa<UnresolvedDeclRefExpr>(anchor)) {
|
|
// Overloaded and unresolved cases: find the resolved overload.
|
|
auto anchorLocator = cs.getConstraintLocator(anchor);
|
|
if (auto selected = findOvlChoice(anchorLocator)) {
|
|
if (selected->choice.isDecl())
|
|
declRef = getConcreteDeclRefFromOverload(*selected);
|
|
}
|
|
} else if (isa<UnresolvedMemberExpr>(anchor)) {
|
|
// Unresolved member: find the resolved overload.
|
|
auto anchorLocator = cs.getConstraintLocator(
|
|
anchor,
|
|
ConstraintLocator::UnresolvedMember);
|
|
if (auto selected = findOvlChoice(anchorLocator)) {
|
|
if (selected->choice.isDecl())
|
|
declRef = getConcreteDeclRefFromOverload(*selected);
|
|
}
|
|
} else if (auto ctorRef = dyn_cast<OtherConstructorDeclRefExpr>(anchor)) {
|
|
declRef = ctorRef->getDeclRef();
|
|
}
|
|
|
|
// If we didn't find the declaration, we're out of luck.
|
|
if (!declRef)
|
|
return ResolvedLocator();
|
|
|
|
// Use the declaration and the path to produce a more specific result.
|
|
// FIXME: This is an egregious hack. We'd be far better off
|
|
// FIXME: Perform deeper path resolution?
|
|
auto path = locator->getPath();
|
|
Pattern *parameterPattern = nullptr;
|
|
bool impliesFullPattern = false;
|
|
while (!path.empty()) {
|
|
switch (path[0].getKind()) {
|
|
case ConstraintLocator::ApplyArgument:
|
|
// If we're calling into something that has parameters, dig into the
|
|
// actual parameter pattern.
|
|
parameterPattern = getParameterPattern(declRef.getDecl());
|
|
if (!parameterPattern)
|
|
break;
|
|
|
|
impliesFullPattern = true;
|
|
path = path.slice(1);
|
|
continue;
|
|
|
|
case ConstraintLocator::TupleElement:
|
|
case ConstraintLocator::NamedTupleElement:
|
|
if (parameterPattern) {
|
|
unsigned index = path[0].getValue();
|
|
if (auto tuple = dyn_cast<TuplePattern>(
|
|
parameterPattern->getSemanticsProvidingPattern())) {
|
|
parameterPattern = tuple->getFields()[index].getPattern();
|
|
impliesFullPattern = false;
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
parameterPattern = nullptr;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ApplyArgToParam:
|
|
if (parameterPattern) {
|
|
unsigned index = path[0].getValue2();
|
|
if (auto tuple = dyn_cast<TuplePattern>(
|
|
parameterPattern->getSemanticsProvidingPattern())) {
|
|
parameterPattern = tuple->getFields()[index].getPattern();
|
|
impliesFullPattern = false;
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
parameterPattern = nullptr;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ScalarToTuple:
|
|
continue;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
// If we have a parameter pattern that refers to a parameter, grab it.
|
|
if (parameterPattern) {
|
|
parameterPattern = parameterPattern->getSemanticsProvidingPattern();
|
|
if (impliesFullPattern) {
|
|
if (auto tuple = dyn_cast<TuplePattern>(parameterPattern)) {
|
|
if (tuple->getFields().size() == 1) {
|
|
parameterPattern = tuple->getFields()[0].getPattern();
|
|
parameterPattern = parameterPattern->getSemanticsProvidingPattern();
|
|
}
|
|
}
|
|
}
|
|
|
|
if (auto named = dyn_cast<NamedPattern>(parameterPattern)) {
|
|
return ResolvedLocator(ResolvedLocator::ForVar, named->getDecl());
|
|
}
|
|
}
|
|
|
|
// Otherwise, do the best we can with the declaration we found.
|
|
if (isa<FuncDecl>(declRef.getDecl()))
|
|
return ResolvedLocator(ResolvedLocator::ForFunction, declRef);
|
|
if (isa<ConstructorDecl>(declRef.getDecl()))
|
|
return ResolvedLocator(ResolvedLocator::ForConstructor, declRef);
|
|
|
|
// FIXME: Deal with the other interesting cases here, e.g.,
|
|
// subscript declarations.
|
|
return ResolvedLocator();
|
|
}
|
|
|
|
/// Emit a note referring to the target of a diagnostic, e.g., the function
|
|
/// or parameter being used.
|
|
static void noteTargetOfDiagnostic(ConstraintSystem &cs,
|
|
const Failure &failure,
|
|
ConstraintLocator *targetLocator) {
|
|
// If there's no anchor, there's nothing we can do.
|
|
if (!targetLocator->getAnchor())
|
|
return;
|
|
|
|
// Try to resolve the locator to a particular declaration.
|
|
auto resolved
|
|
= resolveLocatorToDecl(cs, targetLocator,
|
|
[&](ConstraintLocator *locator) -> Optional<SelectedOverload> {
|
|
for (auto resolved = failure.getResolvedOverloadSets();
|
|
resolved; resolved = resolved->Previous) {
|
|
if (resolved->Locator == locator)
|
|
return SelectedOverload{resolved->Choice,
|
|
resolved->OpenedFullType,
|
|
// FIXME: opened type?
|
|
Type()};
|
|
}
|
|
|
|
return None;
|
|
},
|
|
[&](ValueDecl *decl,
|
|
Type openedType) -> ConcreteDeclRef {
|
|
return decl;
|
|
});
|
|
|
|
// We couldn't resolve the locator to a declaration, so we're done.
|
|
if (!resolved)
|
|
return;
|
|
|
|
switch (resolved.getKind()) {
|
|
case ResolvedLocatorKind::Unresolved:
|
|
// Can't emit any diagnostic here.
|
|
return;
|
|
|
|
case ResolvedLocatorKind::Function: {
|
|
auto name = resolved.getDecl().getDecl()->getName();
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
name.isOperator()? diag::note_call_to_operator
|
|
: diag::note_call_to_func,
|
|
resolved.getDecl().getDecl()->getName());
|
|
return;
|
|
}
|
|
|
|
case ResolvedLocatorKind::Constructor:
|
|
// FIXME: Specialize for implicitly-generated constructors.
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
diag::note_call_to_initializer);
|
|
return;
|
|
|
|
case ResolvedLocatorKind::Parameter:
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
diag::note_init_parameter,
|
|
resolved.getDecl().getDecl()->getName());
|
|
return;
|
|
}
|
|
}
|
|
|
|
/// \brief Emit a diagnostic for the given failure.
|
|
///
|
|
/// \param cs The constraint system in which the diagnostic was generated.
|
|
/// \param failure The failure to emit.
|
|
/// \param expr The expression associated with the failure.
|
|
/// \param useExprLoc If the failure lacks a location, use the one associated
|
|
/// with expr.
|
|
///
|
|
/// \returns true if the diagnostic was emitted successfully.
|
|
static bool diagnoseFailure(ConstraintSystem &cs,
|
|
Failure &failure,
|
|
Expr *expr,
|
|
bool useExprLoc) {
|
|
ConstraintLocator *cloc;
|
|
if (!failure.getLocator() || !failure.getLocator()->getAnchor()) {
|
|
if (useExprLoc)
|
|
cloc = cs.getConstraintLocator(expr);
|
|
else
|
|
return false;
|
|
} else {
|
|
cloc = failure.getLocator();
|
|
}
|
|
|
|
SourceRange range1, range2;
|
|
|
|
ConstraintLocator *targetLocator;
|
|
auto locator = simplifyLocator(cs, cloc, range1, range2,
|
|
&targetLocator);
|
|
auto &tc = cs.getTypeChecker();
|
|
|
|
auto anchor = locator->getAnchor();
|
|
auto loc = anchor->getLoc();
|
|
switch (failure.getKind()) {
|
|
case Failure::TupleSizeMismatch: {
|
|
auto tuple1 = failure.getFirstType()->castTo<TupleType>();
|
|
auto tuple2 = failure.getSecondType()->castTo<TupleType>();
|
|
tc.diagnose(loc, diag::invalid_tuple_size, tuple1, tuple2,
|
|
tuple1->getFields().size(),
|
|
tuple2->getFields().size())
|
|
.highlight(range1).highlight(range2);
|
|
break;
|
|
}
|
|
|
|
case Failure::TupleUnused:
|
|
tc.diagnose(loc, diag::invalid_tuple_element_unused,
|
|
failure.getFirstType(),
|
|
failure.getSecondType())
|
|
.highlight(range1).highlight(range2);
|
|
break;
|
|
|
|
case Failure::TypesNotConvertible:
|
|
case Failure::TypesNotEqual:
|
|
case Failure::TypesNotSubtypes:
|
|
case Failure::TypesNotConstructible:
|
|
case Failure::FunctionTypesMismatch: {
|
|
|
|
// We can do a better job of diagnosing application argument conversion
|
|
// failures elsewhere.
|
|
if (isa<ApplyExpr>(expr) ||
|
|
isa<InOutExpr>(expr) ||
|
|
isa<AssignExpr>(expr))
|
|
return false;
|
|
|
|
tc.diagnose(loc, diag::invalid_relation,
|
|
failure.getKind() - Failure::TypesNotEqual,
|
|
failure.getFirstType(),
|
|
failure.getSecondType())
|
|
.highlight(range1).highlight(range2);
|
|
if (targetLocator && !useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
}
|
|
break;
|
|
|
|
case Failure::DoesNotHaveMember:
|
|
case Failure::DoesNotHaveNonMutatingMember:
|
|
if (auto moduleTy = failure.getFirstType()->getAs<ModuleType>()) {
|
|
tc.diagnose(loc, diag::no_member_of_module,
|
|
moduleTy->getModule()->Name,
|
|
failure.getName())
|
|
.highlight(range1).highlight(range2);
|
|
} else {
|
|
bool IsNoMember = failure.getKind() == Failure::DoesNotHaveMember;
|
|
|
|
tc.diagnose(loc, IsNoMember ? diag::does_not_have_member :
|
|
diag::does_not_have_non_mutating_member,
|
|
failure.getFirstType(),
|
|
failure.getName())
|
|
.highlight(range1).highlight(range2);
|
|
}
|
|
break;
|
|
|
|
case Failure::DoesNotConformToProtocol:
|
|
// FIXME: Probably want to do this within the actual solver, because at
|
|
// this point it's too late to actually recover fully.
|
|
|
|
// We can do a better job of diagnosing application argument conversion
|
|
// failures elsewhere.
|
|
if (isa<ApplyExpr>(expr) ||
|
|
isa<InOutExpr>(expr) ||
|
|
isa<AssignExpr>(expr))
|
|
return false;
|
|
|
|
tc.conformsToProtocol(failure.getFirstType(),
|
|
failure.getSecondType()->castTo<ProtocolType>()
|
|
->getDecl(),
|
|
cs.DC,
|
|
true,
|
|
nullptr,
|
|
loc);
|
|
if (targetLocator)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
|
|
case Failure::IsNotBridgedToObjectiveC:
|
|
tc.diagnose(loc, diag::type_not_bridged, failure.getFirstType());
|
|
if (targetLocator)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
|
|
case Failure::IsForbiddenLValue:
|
|
if (auto iotTy = failure.getSecondType()->getAs<InOutType>()) {
|
|
tc.diagnose(loc, diag::reference_non_inout, iotTy->getObjectType())
|
|
.highlight(range1).highlight(range2);
|
|
return true;
|
|
}
|
|
// FIXME: diagnose other cases
|
|
return false;
|
|
|
|
case Failure::OutOfOrderArgument:
|
|
if (auto tuple = dyn_cast_or_null<TupleExpr>(anchor)) {
|
|
unsigned firstIdx = failure.getValue();
|
|
Identifier first = tuple->getElementName(firstIdx);
|
|
unsigned secondIdx = failure.getSecondValue();
|
|
Identifier second = tuple->getElementName(secondIdx);
|
|
if (!first.empty() && !second.empty()) {
|
|
tc.diagnose(tuple->getElementNameLoc(firstIdx),
|
|
diag::argument_out_of_order, first, second)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange())
|
|
.highlight(SourceRange(tuple->getElementNameLoc(secondIdx),
|
|
tuple->getElement(secondIdx)->getEndLoc()));
|
|
return true;
|
|
}
|
|
}
|
|
// FIXME: Can this even happen?
|
|
return false;
|
|
|
|
case Failure::MissingArgument: {
|
|
Identifier name;
|
|
unsigned idx = failure.getValue();
|
|
if (auto tupleTy = failure.getFirstType()->getAs<TupleType>()) {
|
|
name = tupleTy->getFields()[idx].getName();
|
|
} else {
|
|
// Scalar.
|
|
assert(idx == 0);
|
|
}
|
|
|
|
if (name.empty())
|
|
tc.diagnose(loc, diag::missing_argument_positional, idx+1);
|
|
else
|
|
tc.diagnose(loc, diag::missing_argument_named, name);
|
|
return true;
|
|
}
|
|
|
|
case Failure::ExtraArgument: {
|
|
if (auto tuple = dyn_cast_or_null<TupleExpr>(anchor)) {
|
|
unsigned firstIdx = failure.getValue();
|
|
auto name = tuple->getElementName(firstIdx);
|
|
if (name.empty())
|
|
tc.diagnose(loc, diag::extra_argument_positional)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange());
|
|
else
|
|
tc.diagnose(loc, diag::extra_argument_named, name)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
case Failure::IsNotOptional: {
|
|
if (auto force = dyn_cast_or_null<ForceValueExpr>(anchor)) {
|
|
// If there was an 'as' cast in the subexpression, note it.
|
|
if (auto cast = findForcedDowncast(tc.Context, force->getSubExpr())) {
|
|
tc.diagnose(force->getLoc(), diag::forcing_explicit_downcast,
|
|
failure.getFirstType())
|
|
.highlight(cast->getLoc())
|
|
.fixItRemove(force->getLoc());
|
|
return true;
|
|
}
|
|
|
|
tc.diagnose(loc, diag::forcing_injected_optional,
|
|
failure.getFirstType())
|
|
.highlight(force->getSourceRange())
|
|
.fixItRemove(force->getExclaimLoc());
|
|
|
|
return true;
|
|
}
|
|
|
|
if (auto bind = dyn_cast_or_null<BindOptionalExpr>(anchor)) {
|
|
tc.diagnose(loc, diag::binding_injected_optional,
|
|
failure.getFirstType())
|
|
.highlight(bind->getSourceRange())
|
|
.fixItRemove(bind->getQuestionLoc());
|
|
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
case Failure::NoPublicInitializers: {
|
|
tc.diagnose(loc, diag::no_accessible_initializers, failure.getFirstType())
|
|
.highlight(range1);
|
|
if (targetLocator && !useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
}
|
|
|
|
case Failure::UnboundGenericParameter: {
|
|
tc.diagnose(loc, diag::unbound_generic_parameter, failure.getFirstType())
|
|
.highlight(range1);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::ExistentialGenericParameter: {
|
|
tc.diagnose(loc, diag::generic_parameter_binds_to_non_objc_existential,
|
|
failure.getFirstType(), failure.getSecondType())
|
|
.highlight(range1);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::FunctionAutoclosureMismatch:
|
|
case Failure::FunctionNoReturnMismatch:
|
|
case Failure::IsNotArchetype:
|
|
case Failure::IsNotClass:
|
|
case Failure::IsNotDynamicLookup:
|
|
case Failure::IsNotMetatype:
|
|
case Failure::TupleNameMismatch:
|
|
case Failure::TupleNamePositionMismatch:
|
|
case Failure::TupleVariadicMismatch:
|
|
// FIXME: Handle all failure kinds
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// \brief Determine the number of distinct overload choices in the
|
|
/// provided set.
|
|
static unsigned countDistinctOverloads(ArrayRef<OverloadChoice> choices) {
|
|
llvm::SmallPtrSet<void *, 4> uniqueChoices;
|
|
unsigned result = 0;
|
|
for (auto choice : choices) {
|
|
if (uniqueChoices.insert(choice.getOpaqueChoiceSimple()).second)
|
|
++result;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// \brief Determine the name of the overload in a set of overload choices.
|
|
static Identifier getOverloadChoiceName(ArrayRef<OverloadChoice> choices) {
|
|
for (auto choice : choices) {
|
|
if (choice.isDecl())
|
|
return choice.getDecl()->getName();
|
|
}
|
|
|
|
return Identifier();
|
|
}
|
|
|
|
bool diagnoseAmbiguity(ConstraintSystem &cs, ArrayRef<Solution> solutions) {
|
|
// Produce a diff of the solutions.
|
|
SolutionDiff diff(solutions);
|
|
|
|
// Find the locators which have the largest numbers of distinct overloads.
|
|
SmallVector<unsigned, 2> mostDistinctOverloads;
|
|
unsigned maxDistinctOverloads = 0;
|
|
for (unsigned i = 0, n = diff.overloads.size(); i != n; ++i) {
|
|
auto &overload = diff.overloads[i];
|
|
|
|
// If we can't resolve the locator to an anchor expression with no path,
|
|
// we can't diagnose this well.
|
|
if (!simplifyLocatorToAnchor(cs, overload.locator))
|
|
continue;
|
|
|
|
// If we don't have a name to hang on to, it'll be hard to diagnose this
|
|
// overload.
|
|
if (getOverloadChoiceName(overload.choices).empty())
|
|
continue;
|
|
|
|
unsigned distinctOverloads = countDistinctOverloads(overload.choices);
|
|
|
|
// We need at least two overloads to make this interesting.
|
|
if (distinctOverloads < 2)
|
|
continue;
|
|
|
|
// If we have more distinct overload choices for this locator than for
|
|
// prior locators, just keep this locator.
|
|
if (distinctOverloads > maxDistinctOverloads) {
|
|
maxDistinctOverloads = distinctOverloads;
|
|
mostDistinctOverloads.clear();
|
|
mostDistinctOverloads.push_back(i);
|
|
continue;
|
|
}
|
|
|
|
// If we have as many distinct overload choices for this locator as
|
|
// the best so far, add this locator to the set.
|
|
if (distinctOverloads == maxDistinctOverloads) {
|
|
mostDistinctOverloads.push_back(i);
|
|
continue;
|
|
}
|
|
|
|
// We have better results. Ignore this one.
|
|
}
|
|
|
|
// FIXME: Should be able to pick the best locator, e.g., based on some
|
|
// depth-first numbering of expressions.
|
|
if (mostDistinctOverloads.size() == 1) {
|
|
auto &overload = diff.overloads[mostDistinctOverloads[0]];
|
|
auto name = getOverloadChoiceName(overload.choices);
|
|
auto anchor = simplifyLocatorToAnchor(cs, overload.locator);
|
|
|
|
// Emit the ambiguity diagnostic.
|
|
auto &tc = cs.getTypeChecker();
|
|
tc.diagnose(anchor->getLoc(),
|
|
name.isOperator() ? diag::ambiguous_operator_ref
|
|
: diag::ambiguous_decl_ref,
|
|
name);
|
|
|
|
// Emit candidates. Use a SmallPtrSet to make sure only emit a particular
|
|
// candidate once. FIXME: Why is one candidate getting into the overload
|
|
// set multiple times?
|
|
SmallPtrSet<Decl*, 8> EmittedDecls;
|
|
for (auto choice : overload.choices) {
|
|
switch (choice.getKind()) {
|
|
case OverloadChoiceKind::Decl:
|
|
case OverloadChoiceKind::DeclViaDynamic:
|
|
case OverloadChoiceKind::TypeDecl:
|
|
case OverloadChoiceKind::DeclViaBridge:
|
|
case OverloadChoiceKind::DeclViaUnwrappedOptional:
|
|
// FIXME: show deduced types, etc, etc.
|
|
if (EmittedDecls.insert(choice.getDecl()).second)
|
|
tc.diagnose(choice.getDecl(), diag::found_candidate);
|
|
break;
|
|
|
|
case OverloadChoiceKind::BaseType:
|
|
case OverloadChoiceKind::TupleIndex:
|
|
// FIXME: Actually diagnose something here.
|
|
break;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// FIXME: If we inferred different types for literals (for example),
|
|
// could diagnose ambiguity that way as well.
|
|
|
|
return false;
|
|
}
|
|
|
|
Constraint *getConstraintChoice(Constraint *constraint,
|
|
ConstraintKind kind,
|
|
bool takeAny = false) {
|
|
if ((constraint->getKind() != ConstraintKind::Disjunction) &&
|
|
(constraint->getKind() != ConstraintKind::Conjunction)) {
|
|
return nullptr;
|
|
}
|
|
|
|
auto nestedConstraints = constraint->getNestedConstraints();
|
|
|
|
for (auto nestedConstraint : nestedConstraints) {
|
|
if (takeAny ||
|
|
(nestedConstraint->getKind() == kind)) {
|
|
|
|
// If this is a last-chance search, and we have a conjunction or
|
|
// disjunction, look within.
|
|
if (takeAny &&
|
|
((nestedConstraint->getKind() == ConstraintKind::Disjunction) ||
|
|
(nestedConstraint->getKind() == ConstraintKind::Conjunction))) {
|
|
return getConstraintChoice(nestedConstraint,
|
|
kind,
|
|
takeAny);
|
|
}
|
|
|
|
return nestedConstraint;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Constraint *getComponentConstraint(Constraint *constraint) {
|
|
if (constraint->getKind() != ConstraintKind::Disjunction) {
|
|
return constraint;
|
|
}
|
|
|
|
return constraint->getNestedConstraints().front();
|
|
}
|
|
|
|
/// For a given expression type, extract the appropriate type for a constraint-
|
|
/// based diagnostic.
|
|
static Type getDiagnosticTypeFromExpr(Expr *expr) {
|
|
|
|
// For an unresolved checked cast expression, use the type of the
|
|
// sub-expression.
|
|
if (auto ucc = dyn_cast<UnresolvedCheckedCastExpr>(expr)) {
|
|
auto subExpr = ucc->getSubExpr();
|
|
|
|
return subExpr->getType();
|
|
}
|
|
|
|
// For an application expression, use the argument type.
|
|
if (auto applyExpr = dyn_cast<ApplyExpr>(expr)) {
|
|
return applyExpr->getArg()->getType();
|
|
}
|
|
|
|
// For a subscript expression, use the index type.
|
|
if (auto subscriptExpr = dyn_cast<SubscriptExpr>(expr)) {
|
|
return subscriptExpr->getIndex()->getType();
|
|
}
|
|
|
|
return expr->getType();
|
|
}
|
|
|
|
/// If a type variable was created for an opened literal expression, substitute
|
|
/// in the default literal for the type variable's literal conformance.
|
|
static Type substituteLiteralForTypeVariable(ConstraintSystem *CS,
|
|
TypeVariableType *tv) {
|
|
if (auto proto = tv->getImpl().literalConformanceProto) {
|
|
|
|
auto kind = proto->getKnownProtocolKind();
|
|
|
|
if (kind.hasValue()) {
|
|
auto altLits = CS->getAlternativeLiteralTypes(kind.getValue());
|
|
if (!altLits.empty()) {
|
|
if (auto altType = altLits[0]) {
|
|
return altType;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return tv;
|
|
}
|
|
|
|
static std::pair<Type, Type> getBoundTypesFromConstraint(ConstraintSystem *CS,
|
|
Expr *expr,
|
|
Constraint *constraint) {
|
|
auto type1 = getDiagnosticTypeFromExpr(expr);
|
|
auto type2 = constraint->getSecondType();
|
|
|
|
if (type1->isEqual(type2))
|
|
if (auto firstType = constraint->getFirstType())
|
|
type1 = firstType;
|
|
|
|
if (auto typeVariableType =
|
|
dyn_cast<TypeVariableType>(type2.getPointer())) {
|
|
SmallVector<Type, 4> bindings;
|
|
CS->getComputedBindings(typeVariableType, bindings);
|
|
auto binding = bindings.size() ? bindings.front() : Type();
|
|
|
|
if (!binding.isNull()) {
|
|
if (binding.getPointer() != type1.getPointer())
|
|
type2 = binding;
|
|
} else {
|
|
auto impl = typeVariableType->getImpl();
|
|
if (auto archetypeType = impl.getArchetype()) {
|
|
type2 = archetypeType;
|
|
} else {
|
|
auto implAnchor = impl.getLocator()->getAnchor();
|
|
auto anchorType = implAnchor->getType();
|
|
|
|
// Don't re-substitute an opened type variable for itself.
|
|
if (anchorType.getPointer() != type1.getPointer())
|
|
type2 = anchorType;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (auto typeVariableType =
|
|
dyn_cast<TypeVariableType>(type1.getPointer())) {
|
|
SmallVector<Type, 4> bindings;
|
|
|
|
CS->getComputedBindings(typeVariableType, bindings);
|
|
|
|
for (auto binding : bindings) {
|
|
if (type2.getPointer() != binding.getPointer()) {
|
|
type1 = binding;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// If we still have a literal type variable, substitute in the default type.
|
|
if (auto tv1 = type1->getAs<TypeVariableType>()) {
|
|
type1 = substituteLiteralForTypeVariable(CS, tv1);
|
|
}
|
|
if (auto tv2 = type2->getAs<TypeVariableType>()) {
|
|
type2 = substituteLiteralForTypeVariable(CS, tv2);
|
|
}
|
|
|
|
return std::pair<Type, Type>(type1->getLValueOrInOutObjectType(),
|
|
type2->getLValueOrInOutObjectType());
|
|
}
|
|
|
|
/// Determine if a type resulting from a failed typecheck operation is fully-
|
|
/// specialized, or if it still has type variable type arguments.
|
|
/// (This diverges slightly from hasTypeVariable, in that certain tyvars,
|
|
/// such as for nil literals, will be treated as specialized.)
|
|
bool typeIsNotSpecialized(Type type) {
|
|
if (type.isNull())
|
|
return true;
|
|
|
|
if (auto tv = type->getAs<TypeVariableType>()) {
|
|
|
|
// If it's a nil-literal conformance, there's no reason to re-specialize.
|
|
if (tv->getImpl().literalConformanceProto) {
|
|
|
|
auto knownProtoKind =
|
|
tv->getImpl().literalConformanceProto->getKnownProtocolKind();
|
|
|
|
if (knownProtoKind.hasValue() &&
|
|
(knownProtoKind.getValue() ==
|
|
KnownProtocolKind::NilLiteralConvertible)) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Desugar, if necessary.
|
|
if (auto sugaredTy = type->getAs<SyntaxSugarType>())
|
|
type = sugaredTy->getBaseType();
|
|
|
|
// If it's generic, check the type arguments.
|
|
if (auto bgt = type->getAs<BoundGenericType>()) {
|
|
for (auto tyarg : bgt->getGenericArgs()) {
|
|
if (typeIsNotSpecialized(tyarg))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// If it's a tuple, check the members.
|
|
if (auto tupleTy = type->getAs<TupleType>()) {
|
|
for (auto elementTy : tupleTy->getElementTypes()) {
|
|
if (typeIsNotSpecialized((elementTy)))
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
// If it's an inout type, check the inner type.
|
|
if (auto inoutTy = type->getAs<InOutType>()) {
|
|
return typeIsNotSpecialized(inoutTy->getObjectType());
|
|
}
|
|
|
|
// If it's a function, check the parameter and return types.
|
|
if (auto functionTy = type->getAs<AnyFunctionType>()) {
|
|
if (typeIsNotSpecialized(functionTy->getResult()) ||
|
|
typeIsNotSpecialized(functionTy->getInput()))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
// Otherwise, broadly check for type variables.
|
|
return type->hasTypeVariable();
|
|
}
|
|
|
|
/// Obtain the colloquial description for a known protocol kind.
|
|
std::string getDescriptionForKnownProtocolKind(KnownProtocolKind kind) {
|
|
switch (kind) {
|
|
#define PROTOCOL(Id) \
|
|
case KnownProtocolKind::Id: \
|
|
return #Id;
|
|
|
|
#define LITERAL_CONVERTIBLE_PROTOCOL(Id, Description) \
|
|
case KnownProtocolKind::Id: \
|
|
return #Description;
|
|
|
|
#define BUILTIN_LITERAL_CONVERTIBLE_PROTOCOL(Id) \
|
|
case KnownProtocolKind::Id: \
|
|
return #Id;
|
|
|
|
#include "swift/AST/KnownProtocols.def"
|
|
}
|
|
|
|
llvm_unreachable("unrecognized known protocol kind");
|
|
}
|
|
|
|
/// Determine if the type is an error type, or its metatype.
|
|
bool isErrorTypeKind(Type t) {
|
|
|
|
if (auto mt = t->getAs<MetatypeType>())
|
|
t = mt->getInstanceType();
|
|
|
|
return t->is<ErrorType>();
|
|
}
|
|
|
|
/// Obtain a "user friendly" type name. E.g., one that uses colloquial names
|
|
/// for literal convertible protocols if necessary, and is devoid of type
|
|
/// variables.
|
|
std::string getUserFriendlyTypeName(Type t, bool unwrap = true) {
|
|
|
|
assert(!t.isNull());
|
|
|
|
// Unwrap any l-value types.
|
|
if (unwrap) {
|
|
if (auto lv = t->getAs<LValueType>()) {
|
|
t = lv->getObjectType();
|
|
}
|
|
}
|
|
|
|
if (auto tv = t->getAs<TypeVariableType>()) {
|
|
if (tv->getImpl().literalConformanceProto) {
|
|
Optional<KnownProtocolKind> kind =
|
|
tv->getImpl().literalConformanceProto->getKnownProtocolKind();
|
|
|
|
if (kind.hasValue()) {
|
|
return getDescriptionForKnownProtocolKind(kind.getValue());
|
|
}
|
|
}
|
|
}
|
|
|
|
return t.getString();
|
|
}
|
|
|
|
/// Conveniently unwrap a paren expression, if necessary.
|
|
Expr* unwrapParenExpr(Expr *e) {
|
|
if (auto parenExpr = dyn_cast<ParenExpr>(e))
|
|
return unwrapParenExpr(parenExpr->getSubExpr());
|
|
|
|
return e;
|
|
}
|
|
|
|
/// Given a vector of types, obtain a stringified comma-separated list of their
|
|
/// associated "user friendly" type names.
|
|
std::string getTypeListString(SmallVectorImpl<Type> &types) {
|
|
|
|
std::string typeList = "";
|
|
|
|
if (types.size()) {
|
|
typeList += getUserFriendlyTypeName(types[0]);
|
|
|
|
for (size_t i = 1; i < types.size(); i++)
|
|
typeList += ", " + getUserFriendlyTypeName(types[i]);
|
|
}
|
|
|
|
return typeList;
|
|
|
|
}
|
|
|
|
GeneralFailureDiagnosis::GeneralFailureDiagnosis(Expr *expr,
|
|
ConstraintSystem *cs) :
|
|
expr(expr), CS(cs) {
|
|
|
|
assert(expr && CS);
|
|
|
|
// Collect and categorize constraint information from the failed system.
|
|
|
|
if(!CS->ActiveConstraints.empty()) {
|
|
// If any active conformance constraints are in the system, we know that
|
|
// any inactive constraints are in its service. Capture the constraint and
|
|
// present this information to the user.
|
|
auto *constraint = &CS->ActiveConstraints.front();
|
|
|
|
activeConformanceConstraint = getComponentConstraint(constraint);
|
|
}
|
|
|
|
for (auto & constraintRef : CS->InactiveConstraints) {
|
|
auto constraint = &constraintRef;
|
|
|
|
// Capture the first non-disjunction constraint we find. We'll use this
|
|
// if we can't find a clearer reason for the failure.
|
|
if ((!fallbackConstraint || constraint->isFavored()) &&
|
|
(constraint->getKind() != ConstraintKind::Disjunction) &&
|
|
(constraint->getKind() != ConstraintKind::Conjunction)) {
|
|
fallbackConstraint = constraint;
|
|
}
|
|
|
|
// Store off conversion constraints, favoring existing conversion
|
|
// constraints.
|
|
if ((!(activeConformanceConstraint ||
|
|
conformanceConstraint) || constraint->isFavored()) &&
|
|
constraint->getKind() == ConstraintKind::ConformsTo) {
|
|
conformanceConstraint = constraint;
|
|
}
|
|
|
|
// Failed binding constraints point to a missing member.
|
|
if ((!valueMemberConstraint || constraint->isFavored()) &&
|
|
((constraint->getKind() == ConstraintKind::ValueMember) ||
|
|
(constraint->getKind() == ConstraintKind::UnresolvedValueMember))) {
|
|
valueMemberConstraint = constraint;
|
|
}
|
|
|
|
// A missed argument conversion can result in better error messages when
|
|
// a user passes the wrong arguments to a function application.
|
|
if ((!argumentConstraint || constraint->isFavored())) {
|
|
argumentConstraint = getConstraintChoice(constraint,
|
|
ConstraintKind::
|
|
ArgumentTupleConversion);
|
|
}
|
|
|
|
// Overload resolution failures are often nicely descriptive, so store
|
|
// off the first one we find.
|
|
if ((!overloadConstraint || constraint->isFavored())) {
|
|
overloadConstraint = getConstraintChoice(constraint,
|
|
ConstraintKind::BindOverload);
|
|
}
|
|
|
|
// Conversion constraints are also nicely descriptive, so we'll grab the
|
|
// first one of those as well.
|
|
if ((!conversionConstraint || constraint->isFavored()) &&
|
|
(constraint->getKind() == ConstraintKind::Conversion ||
|
|
constraint->getKind() == ConstraintKind::ArgumentTupleConversion)) {
|
|
conversionConstraint = constraint;
|
|
}
|
|
|
|
// Also check for bridging failures.
|
|
if ((!bridgeToObjCConstraint || constraint->isFavored()) &&
|
|
constraint->getKind() == ConstraintKind::BridgedToObjectiveC) {
|
|
bridgeToObjCConstraint = constraint;
|
|
}
|
|
|
|
// When all else fails, inspect a potential conjunction or disjunction for a
|
|
// consituent conversion.
|
|
if (!disjunctionConversionConstraint || constraint->isFavored()) {
|
|
disjunctionConversionConstraint =
|
|
getConstraintChoice(constraint, ConstraintKind::Conversion, true);
|
|
}
|
|
}
|
|
|
|
// If no more descriptive constraint was found, use the fallback constraint.
|
|
if (fallbackConstraint &&
|
|
!(conversionConstraint ||
|
|
overloadConstraint ||
|
|
argumentConstraint)) {
|
|
|
|
if (fallbackConstraint->getKind() == ConstraintKind::ArgumentConversion)
|
|
argumentConstraint = fallbackConstraint;
|
|
else
|
|
conversionConstraint = fallbackConstraint;
|
|
}
|
|
|
|
// If there's still no conversion to diagnose, use the disjunction conversion.
|
|
if (!conversionConstraint) {
|
|
conversionConstraint = disjunctionConversionConstraint;
|
|
}
|
|
|
|
// If there was already a conversion failure, use it.
|
|
if (!conversionConstraint &&
|
|
CS->failedConstraint &&
|
|
CS->failedConstraint->getKind() != ConstraintKind::Disjunction) {
|
|
conversionConstraint = CS->failedConstraint;
|
|
}
|
|
}
|
|
|
|
bool GeneralFailureDiagnosis::diagnoseGeneralValueMemberFailure() {
|
|
|
|
if (valueMemberConstraint) {
|
|
auto memberName = valueMemberConstraint->getMember().getBaseName();
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::could_not_find_member,
|
|
memberName)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool GeneralFailureDiagnosis::diagnoseGeneralOverloadFailure() {
|
|
|
|
// In the absense of a better conversion constraint failure, point out the
|
|
// inability to find an appropriate overload.
|
|
if (overloadConstraint) {
|
|
auto overloadChoice = overloadConstraint->getOverloadChoice();
|
|
auto overloadName = overloadChoice.getDecl()->getName();
|
|
Type argType = getDiagnosticTypeFromExpr(expr);
|
|
|
|
if (!argType.isNull() &&
|
|
!argType->getAs<TypeVariableType>() &&
|
|
isa<ApplyExpr>(expr)) {
|
|
if (argType->getAs<TupleType>()) {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload_with_type_list,
|
|
overloadName.str(), argType)
|
|
.highlight(expr->getSourceRange());
|
|
} else {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload_with_type,
|
|
overloadName.str(),
|
|
argType)
|
|
.highlight(expr->getSourceRange());
|
|
}
|
|
} else {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload,
|
|
overloadName.str())
|
|
.highlight(expr->getSourceRange());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool GeneralFailureDiagnosis::diagnoseGeneralConversionFailure() {
|
|
|
|
// Otherwise, if we have a conversion constraint, use that as the basis for
|
|
// the diagnostic.
|
|
if (conversionConstraint || argumentConstraint) {
|
|
auto constraint = argumentConstraint ?
|
|
argumentConstraint :
|
|
conversionConstraint;
|
|
|
|
if (conformanceConstraint) {
|
|
if (conformanceConstraint->getTypeVariables().size() <
|
|
constraint->getTypeVariables().size()) {
|
|
constraint = conformanceConstraint;
|
|
}
|
|
}
|
|
|
|
auto locator = constraint->getLocator();
|
|
auto anchor = locator ? locator->getAnchor() : expr;
|
|
std::pair<Type, Type> types = getBoundTypesFromConstraint(CS,
|
|
expr,
|
|
constraint);
|
|
|
|
if (argumentConstraint) {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::could_not_convert_argument,
|
|
types.first).
|
|
highlight(anchor->getSourceRange());
|
|
} else {
|
|
|
|
// If it's a type variable failing a conformance, avoid printing the type
|
|
// variable and just print the conformance.
|
|
if ((constraint->getKind() == ConstraintKind::ConformsTo) &&
|
|
types.first->getAs<TypeVariableType>()) {
|
|
CS->TC.diagnose(anchor->getLoc(),
|
|
diag::single_expression_conformance_failure,
|
|
types.first)
|
|
.highlight(anchor->getSourceRange());
|
|
} else {
|
|
// If the second type is a type variable, the expression itself is
|
|
// ambiguous.
|
|
if (types.first->getAs<UnboundGenericType>() ||
|
|
types.second->getAs<TypeVariableType>()) {
|
|
if (isa<ClosureExpr>(expr)) {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::cannot_infer_closure_type);
|
|
} else {
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::type_of_expression_is_ambiguous);
|
|
}
|
|
} else {
|
|
auto failureKind =
|
|
Failure::TypesNotConvertible - Failure::TypesNotEqual;
|
|
|
|
CS->TC.diagnose(anchor->getLoc(),
|
|
diag::invalid_relation,
|
|
failureKind,
|
|
types.first, types.second)
|
|
.highlight(anchor->getSourceRange());
|
|
}
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool GeneralFailureDiagnosis::diagnoseGeneralFailure() {
|
|
|
|
if (diagnoseGeneralValueMemberFailure() ||
|
|
diagnoseGeneralOverloadFailure() ||
|
|
diagnoseGeneralConversionFailure()) {
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
Type FailureDiagnosis::getTypeOfIndependentSubExpression(Expr *subExpr) {
|
|
|
|
if (!isa<ClosureExpr>(subExpr) &&
|
|
typeIsNotSpecialized(subExpr->getType())) {
|
|
CS->TC.eraseTypeData(subExpr);
|
|
|
|
CS->TC.typeCheckExpression(subExpr, CS->DC, Type(), Type(), false);
|
|
}
|
|
|
|
assert(subExpr->getType());
|
|
|
|
return subExpr->getType();
|
|
}
|
|
|
|
/// FIXME: Right now, a "matching" overload is one with a parameter whose type
|
|
/// is identical to one of the argument types. We can obviously do something
|
|
/// more sophisticated with this.
|
|
void FailureDiagnosis::suggestPotentialOverloads(
|
|
const StringRef functionName,
|
|
const SourceLoc &loc,
|
|
const SmallVectorImpl<Type> ¶mLists,
|
|
const SmallVectorImpl<Type> &argTypes) {
|
|
if (!argTypes.size()) {
|
|
return;
|
|
}
|
|
|
|
std::string suggestionText = "";
|
|
std::map<std::string, bool> dupes;
|
|
auto iPL = 0;
|
|
|
|
for (auto paramList : paramLists) {
|
|
SmallVector<Type, 16> paramTypes;
|
|
|
|
// Assemble the parameter type list.
|
|
if (auto parenType = dyn_cast<ParenType>(paramList.getPointer())) {
|
|
paramTypes.push_back(parenType->getUnderlyingType());
|
|
} else if (auto tupleType = paramList->getAs<TupleType>()) {
|
|
paramTypes.append(tupleType->getElementTypes().begin(),
|
|
tupleType->getElementTypes().end());
|
|
}
|
|
|
|
for (auto pt : paramTypes) {
|
|
for (auto at : argTypes) {
|
|
if (pt->isEqual(at)) {
|
|
auto typeListString = getTypeListString(paramTypes);
|
|
if (!dupes[typeListString]) {
|
|
dupes[typeListString] = true;
|
|
if (iPL)
|
|
suggestionText += ", ";
|
|
iPL++;
|
|
suggestionText += "(" + typeListString + ")";
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!suggestionText.length())
|
|
return;
|
|
|
|
CS->TC.diagnose(loc,
|
|
diag::suggest_partial_overloads,
|
|
functionName,
|
|
suggestionText);
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForBinaryExpr() {
|
|
assert(expr->getKind() == ExprKind::Binary);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto binop = cast<BinaryExpr>(expr);
|
|
|
|
auto argExpr = dyn_cast<TupleExpr>(binop->getArg());
|
|
auto argTuple = getTypeOfIndependentSubExpression(argExpr)->
|
|
getAs<TupleType>();
|
|
|
|
// If the argument type is not a tuple, we've posted the diagnostic
|
|
// recursively.
|
|
if (!argTuple)
|
|
return true;
|
|
|
|
std::string overloadName;
|
|
|
|
SmallVector<Type, 16> paramLists;
|
|
SmallVector<Type, 2> argTypes;
|
|
|
|
if (auto DRE = dyn_cast<DeclRefExpr>(binop->getFn())) {
|
|
overloadName = DRE->getDecl()->getNameStr();
|
|
} else if (auto ODRE = dyn_cast<OverloadedDeclRefExpr>(binop->getFn())) {
|
|
overloadName = ODRE->getDecls()[0]->getNameStr();
|
|
|
|
for (auto DRE : ODRE->getDecls()) {
|
|
if (auto fnType = DRE->getType()->getAs<AnyFunctionType>()) {
|
|
paramLists.push_back(fnType->getInput());
|
|
}
|
|
}
|
|
} else if (overloadConstraint) {
|
|
overloadName = overloadConstraint->getOverloadChoice().
|
|
getDecl()->getName().str();
|
|
} else {
|
|
llvm_unreachable("unrecognized binop function kind");
|
|
}
|
|
|
|
assert(!overloadName.empty());
|
|
|
|
argTypes.push_back(argTuple->getElementType(0));
|
|
argTypes.push_back(argTuple->getElementType(1));
|
|
|
|
auto argTyName1 = getUserFriendlyTypeName(argTypes[0]);
|
|
auto argTyName2 = getUserFriendlyTypeName(argTypes[1]);
|
|
|
|
if (argTyName1.compare(argTyName2)) {
|
|
CS->TC.diagnose(argExpr->getElements()[0]->getLoc(),
|
|
diag::cannot_apply_binop_to_args,
|
|
overloadName,
|
|
argTyName1,
|
|
argTyName2);
|
|
} else {
|
|
CS->TC.diagnose(argExpr->getElements()[0]->getLoc(),
|
|
diag::cannot_apply_binop_to_same_args,
|
|
overloadName,
|
|
argTyName1);
|
|
}
|
|
|
|
if (paramLists.size())
|
|
suggestPotentialOverloads(overloadName,
|
|
argExpr->getElements()[0]->getLoc(),
|
|
paramLists,
|
|
argTypes);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForUnaryExpr() {
|
|
assert(expr->getKind() == ExprKind::PostfixUnary ||
|
|
expr->getKind() == ExprKind::PrefixUnary);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto applyExpr = cast<ApplyExpr>(expr);
|
|
auto argExpr = applyExpr->getArg();
|
|
auto argType = getTypeOfIndependentSubExpression(argExpr);
|
|
|
|
// If the argument type is an error, we've posted the diagnostic
|
|
// recursively.
|
|
if (isErrorTypeKind(argType))
|
|
return true;
|
|
|
|
auto argTyName = getUserFriendlyTypeName(argType);
|
|
|
|
std::string overloadName;
|
|
|
|
if (overloadConstraint) {
|
|
overloadName = overloadConstraint->getOverloadChoice().
|
|
getDecl()->getName().str();
|
|
} else if (auto declRefExpr = dyn_cast<DeclRefExpr>(applyExpr->getFn())) {
|
|
overloadName = declRefExpr->getDecl()->getNameStr();
|
|
} else if (auto overloadedDRE =
|
|
dyn_cast<OverloadedDeclRefExpr>(applyExpr->getFn())) {
|
|
overloadName = overloadedDRE->getDecls()[0]->getNameStr();
|
|
} else {
|
|
llvm_unreachable("unrecognized unop function kind");
|
|
}
|
|
|
|
assert(!overloadName.empty());
|
|
|
|
// FIXME: Note that we don't currently suggest a partially matching overload.
|
|
CS->TC.diagnose(argExpr->getLoc(),
|
|
diag::cannot_apply_unop_to_arg,
|
|
overloadName,
|
|
argTyName);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForPrefixUnaryExpr() {
|
|
return diagnoseFailureForUnaryExpr();
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForPostfixUnaryExpr() {
|
|
return diagnoseFailureForUnaryExpr();
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForSubscriptExpr() {
|
|
assert(expr->getKind() == ExprKind::Subscript ||
|
|
expr->getKind() == ExprKind::PrefixUnary);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto subscriptExpr = cast<SubscriptExpr>(expr);
|
|
auto indexExpr = subscriptExpr->getIndex();
|
|
auto baseExpr = subscriptExpr->getBase();
|
|
|
|
auto indexType = getTypeOfIndependentSubExpression(indexExpr);
|
|
|
|
// Extract the exact argument type from the argument tuple.
|
|
if (auto parenTy = dyn_cast<ParenType>(indexType.getPointer())) {
|
|
indexType = parenTy->getUnderlyingType();
|
|
}
|
|
|
|
// An error has been posted elsewhere.
|
|
if (isErrorTypeKind(indexType))
|
|
return true;
|
|
|
|
auto baseType = getTypeOfIndependentSubExpression(baseExpr);
|
|
|
|
auto indexTypeName = getUserFriendlyTypeName(indexType);
|
|
auto baseTypeName = getUserFriendlyTypeName(baseType);
|
|
|
|
assert(!(indexTypeName.empty() || baseTypeName.empty()));
|
|
|
|
// FIXME: As with unary applications, we don't currently suggest a partially
|
|
// matching overload.
|
|
CS->TC.diagnose(indexExpr->getLoc(),
|
|
diag::cannot_subscript_with_index,
|
|
baseTypeName,
|
|
indexTypeName);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForCallExpr() {
|
|
assert(expr->getKind() == ExprKind::Call);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto callExpr = cast<CallExpr>(expr);
|
|
auto fnExpr = callExpr->getFn();
|
|
auto argExpr = callExpr->getArg();
|
|
|
|
// An error was posted elsewhere.
|
|
if (isErrorTypeKind(fnExpr->getType())) {
|
|
return true;
|
|
}
|
|
|
|
std::string overloadName = "";
|
|
|
|
bool isClosureInvocation = false;
|
|
bool isInvalidTrailingClosureTarget = false;
|
|
bool foundIntermediateError = false;
|
|
bool isInitializer = false;
|
|
bool isOverloadedFn = false;
|
|
|
|
llvm::SmallVector<Type,16> paramLists;
|
|
llvm::SmallVector<Type, 16> argTypes;
|
|
|
|
// Obtain the function's name, and collect any parameter lists for diffing
|
|
// purposes.
|
|
if (auto DRE = dyn_cast<DeclRefExpr>(fnExpr)) {
|
|
overloadName = DRE->getDecl()->getNameStr();
|
|
|
|
if (auto fnType = DRE->getDecl()->getType()->getAs<AnyFunctionType>()) {
|
|
paramLists.push_back(fnType->getInput());
|
|
}
|
|
|
|
} else if (auto ODRE = dyn_cast<OverloadedDeclRefExpr>(fnExpr)) {
|
|
isOverloadedFn = true;
|
|
overloadName = ODRE->getDecls()[0]->getNameStr().str();
|
|
|
|
// Collect the parameters for later use.
|
|
for (auto D : ODRE->getDecls()) {
|
|
if (auto fnType = D->getType()->getAs<AnyFunctionType>()) {
|
|
paramLists.push_back(fnType->getInput());
|
|
}
|
|
}
|
|
|
|
} else if (auto TE = dyn_cast<TypeExpr>(fnExpr)) {
|
|
isInitializer = true;
|
|
|
|
// It's always a metatype type, so use the instance type name.
|
|
auto instanceType = TE->getType()->getAs<MetatypeType>()->getInstanceType();
|
|
overloadName = instanceType->getString();
|
|
} else if (auto UDE = dyn_cast<UnresolvedDotExpr>(fnExpr)) {
|
|
overloadName = UDE->getName().str().str();
|
|
} else {
|
|
isClosureInvocation = true;
|
|
|
|
auto unwrappedExpr = unwrapParenExpr(fnExpr);
|
|
isInvalidTrailingClosureTarget = !isa<ClosureExpr>(unwrappedExpr);
|
|
}
|
|
|
|
// Build the argument type list.
|
|
if (auto parenExpr = dyn_cast<ParenExpr>(argExpr)) {
|
|
auto subType =
|
|
getTypeOfIndependentSubExpression((parenExpr->getSubExpr()));
|
|
|
|
if (isErrorTypeKind(subType))
|
|
foundIntermediateError = true;
|
|
|
|
argTypes.push_back(subType);
|
|
} else if (auto tupleExpr = dyn_cast<TupleExpr>(argExpr)) {
|
|
for (auto elExpr : tupleExpr->getElements()) {
|
|
auto elType = getTypeOfIndependentSubExpression(elExpr);
|
|
|
|
if (isErrorTypeKind(elType))
|
|
foundIntermediateError = true;
|
|
|
|
argTypes.push_back(elType);
|
|
}
|
|
}
|
|
|
|
if (foundIntermediateError)
|
|
return true;
|
|
|
|
if (argTypes.size()) {
|
|
|
|
std::string argString = getTypeListString(argTypes);
|
|
|
|
if (!isOverloadedFn) {
|
|
if (isClosureInvocation) {
|
|
|
|
if (isInvalidTrailingClosureTarget) {
|
|
CS->TC.diagnose(fnExpr->getLoc(),
|
|
diag::invalid_trailing_closure_target);
|
|
} else {
|
|
CS->TC.diagnose(fnExpr->getLoc(),
|
|
diag::cannot_invoke_closure,
|
|
argString);
|
|
}
|
|
} else {
|
|
CS->TC.diagnose(fnExpr->getLoc(),
|
|
isInitializer ?
|
|
diag::cannot_apply_initializer_to_args :
|
|
diag::cannot_apply_function_to_args,
|
|
overloadName,
|
|
argString);
|
|
}
|
|
} else {
|
|
CS->TC.diagnose(fnExpr->getLoc(),
|
|
isInitializer ?
|
|
diag::cannot_find_appropriate_initializer_with_list :
|
|
diag::cannot_find_appropriate_overload_with_list,
|
|
overloadName,
|
|
argString);
|
|
}
|
|
} else {
|
|
|
|
if (isClosureInvocation) {
|
|
CS->TC.diagnose(fnExpr->getLoc(), diag::cannot_infer_closure_type);
|
|
} else {
|
|
CS->TC.diagnose(fnExpr->getLoc(),
|
|
isInitializer ?
|
|
diag::cannot_find_initializer_with_no_params :
|
|
diag::cannot_find_overload_with_no_params,
|
|
overloadName);
|
|
}
|
|
}
|
|
|
|
// Did the user intend on invoking a different overload?
|
|
if (paramLists.size()) {
|
|
if(!isOverloadedFn) {
|
|
std::string paramString = "";
|
|
SmallVector<Type, 16> paramTypes;
|
|
|
|
if (auto parenType = dyn_cast<ParenType>(paramLists[0].getPointer())) {
|
|
paramTypes.push_back(parenType->getUnderlyingType());
|
|
} else if (auto tupleType = paramLists[0]->getAs<TupleType>()) {
|
|
paramTypes.append(tupleType->getElementTypes().begin(),
|
|
tupleType->getElementTypes().end());
|
|
}
|
|
|
|
if (paramTypes.size()) {
|
|
paramString = getTypeListString(paramTypes);
|
|
|
|
CS->TC.diagnose(argExpr->getLoc(),
|
|
diag::expected_certain_args,
|
|
paramString);
|
|
}
|
|
} else {
|
|
suggestPotentialOverloads(overloadName,
|
|
fnExpr->getLoc(),
|
|
paramLists,
|
|
argTypes);
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForAssignExpr() {
|
|
assert(expr->getKind() == ExprKind::Assign);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto assignExpr = cast<AssignExpr>(expr);
|
|
auto destExpr = assignExpr->getDest();
|
|
auto srcExpr = assignExpr->getSrc();
|
|
|
|
auto destType = getTypeOfIndependentSubExpression(destExpr);
|
|
auto srcType = getTypeOfIndependentSubExpression(srcExpr);
|
|
|
|
// If the source type is already an error type, we've likely already posted
|
|
// an error due to a contextual type conversion error.
|
|
if (isErrorTypeKind(srcType) || isErrorTypeKind(destType)) {
|
|
return true;
|
|
}
|
|
|
|
auto destTypeName = getUserFriendlyTypeName(destType);
|
|
auto srcTypeName = getUserFriendlyTypeName(srcType);
|
|
|
|
if (isa<LiteralExpr>(destExpr)) {
|
|
CS->TC.diagnose(destExpr->getLoc(),
|
|
diag::cannot_assign_to_literal,
|
|
destTypeName);
|
|
} else if (!srcTypeName.compare(destTypeName)) {
|
|
|
|
if (destType->is<ArchetypeType>()) {
|
|
CS->TC.diagnose(srcExpr->getLoc(),
|
|
diag::cannot_assign_invariant_self,
|
|
srcTypeName);
|
|
} else {
|
|
|
|
// If the types are the same, this might not be an assignability error -
|
|
// something else may have gone wrong. In that case, independently
|
|
// re-typecheck the source expression to see if there's a different
|
|
// failure.
|
|
CS->TC.eraseTypeData(srcExpr);
|
|
CS->TC.typeCheckExpression(srcExpr, CS->DC, Type(), Type(), false);
|
|
|
|
if (srcExpr->getType()->getAs<ErrorType>())
|
|
return true;
|
|
|
|
CS->TC.diagnose(destExpr->getLoc(),
|
|
diag::cannot_assign_to_immutable_expr,
|
|
destTypeName);
|
|
}
|
|
} else {
|
|
CS->TC.diagnose(srcExpr->getLoc(),
|
|
diag::cannot_assign_values,
|
|
srcTypeName,
|
|
destTypeName);
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailureForInOutExpr() {
|
|
assert(expr->getKind() == ExprKind::InOut);
|
|
|
|
CleanupIllFormedExpressionRAII cleanup(*CS, expr);
|
|
|
|
auto inoutExpr = cast<InOutExpr>(expr);
|
|
auto addressedExpr = inoutExpr->getSubExpr();
|
|
|
|
if (auto DRE = dyn_cast<DeclRefExpr>(addressedExpr)) {
|
|
if (auto VD = dyn_cast<VarDecl>(DRE->getDecl())) {
|
|
if (VD->hasAccessorFunctions() && !VD->getSetter()) {
|
|
CS->TC.diagnose(DRE->getLoc(),
|
|
diag::assignment_get_only_property,
|
|
VD->getName());
|
|
return true;
|
|
}
|
|
|
|
if (VD->isLet()) {
|
|
CS->TC.diagnose(addressedExpr->getLoc(),
|
|
diag::cannot_assign_to_immutable_expr,
|
|
getUserFriendlyTypeName(addressedExpr->getType()));
|
|
return true;
|
|
}
|
|
}
|
|
} else if (isa<UnresolvedDotExpr>(addressedExpr)) {
|
|
// For now, keep the UDE distinct from the above to allow for potentially
|
|
// better diagnostics.
|
|
CS->TC.diagnose(addressedExpr->getLoc(),
|
|
diag::cannot_assign_to_immutable_expr,
|
|
getUserFriendlyTypeName(addressedExpr->getType()));
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseFailure() {
|
|
assert(CS && expr);
|
|
|
|
if (activeConformanceConstraint) {
|
|
std::pair<Type, Type> types =
|
|
getBoundTypesFromConstraint(CS,
|
|
expr,
|
|
activeConformanceConstraint);
|
|
|
|
CS->TC.diagnose(expr->getLoc(),
|
|
diag::does_not_conform_to_constraint,
|
|
types.first,
|
|
types.second)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
// If a bridging conversion slips through, treat it as ambiguous.
|
|
if (bridgeToObjCConstraint) {
|
|
CS->TC.diagnose(expr->getLoc(), diag::type_of_expression_is_ambiguous);
|
|
|
|
return true;
|
|
}
|
|
|
|
// Move on to expr-specific diagnostics.
|
|
switch(expr->getKind()) {
|
|
|
|
#define EXPR(ID, PARENT) \
|
|
case ExprKind::ID: return diagnoseFailureFor##ID##Expr();
|
|
#include "swift/AST/ExprNodes.def"
|
|
|
|
}
|
|
|
|
llvm_unreachable("unrecognized expr kind");
|
|
}
|
|
|
|
/// Given a specific expression and the remnants of the failed constraint
|
|
/// system, produce a specific diagnostic.
|
|
bool ConstraintSystem::diagnoseFailureForExpr(Expr *expr) {
|
|
|
|
FailureDiagnosis diagnosis(expr, this);
|
|
|
|
// Now, attempt to diagnose the failure from the info we've collected.
|
|
if (diagnosis.diagnoseFailure())
|
|
return true;
|
|
|
|
// A DiscardAssignmentExpr is special in that it introduces a new type
|
|
// variable but places no constraints upon it. Instead, it relies on the rhs
|
|
// of its assignment expression to determine its type. Unfortunately, in the
|
|
// case of error recovery, the "_" expression may be left alone with no
|
|
// constraints for us to derive an error from. In that case, we'll fall back
|
|
// to the "outside assignment" error.
|
|
if (ActiveConstraints.empty() &&
|
|
InactiveConstraints.empty() &&
|
|
!failedConstraint) {
|
|
|
|
if (isa<DiscardAssignmentExpr>(expr)) {
|
|
TC.diagnose(expr->getLoc(), diag::discard_expr_outside_of_assignment)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
if (auto dot = dyn_cast<UnresolvedDotExpr>(expr)) {
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::not_enough_context_for_generic_method_reference,
|
|
dot->getName());
|
|
|
|
return true;
|
|
}
|
|
|
|
// If there are no posted constraints or failures, then there was
|
|
// not enough contextual information available to infer a type for the
|
|
// expression.
|
|
TC.diagnose(expr->getLoc(), diag::type_of_expression_is_ambiguous);
|
|
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
bool ConstraintSystem::salvage(SmallVectorImpl<Solution> &viable,
|
|
Expr *expr,
|
|
bool onlyFailures) {
|
|
|
|
// If there were any unavoidable failures, emit the first one we can.
|
|
if (!unavoidableFailures.empty()) {
|
|
for (auto failure : unavoidableFailures) {
|
|
|
|
// In the 'onlyFailures' case, we'll want to synthesize a locator if one
|
|
// does not exist. That allows us to emit decent diagnostics for
|
|
// constraint application failures where the constraints themselves lack
|
|
// a valid location.
|
|
if (diagnoseFailure(*this, *failure, expr, onlyFailures))
|
|
return true;
|
|
}
|
|
|
|
if (onlyFailures)
|
|
return true;
|
|
|
|
// If we can't make sense of the existing constraints (or none exist), go
|
|
// ahead and try the unavoidable failures again, but with locator
|
|
// substitutions in place.
|
|
if (!this->diagnoseFailureForExpr(expr) &&
|
|
!unavoidableFailures.empty()) {
|
|
for (auto failure : unavoidableFailures) {
|
|
if (diagnoseFailure(*this, *failure, expr, true))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// There were no unavoidable failures, so attempt to solve again, capturing
|
|
// any failures that come from our attempts to select overloads or bind
|
|
// type variables.
|
|
{
|
|
viable.clear();
|
|
|
|
// Set up solver state.
|
|
SolverState state(*this);
|
|
state.recordFailures = true;
|
|
this->solverState = &state;
|
|
|
|
// Solve the system.
|
|
solve(viable);
|
|
|
|
// Check whether we have a best solution; this can happen if we found
|
|
// a series of fixes that worked.
|
|
if (auto best = findBestSolution(viable, /*minimize=*/true)) {
|
|
if (*best != 0)
|
|
viable[0] = std::move(viable[*best]);
|
|
viable.erase(viable.begin() + 1, viable.end());
|
|
return false;
|
|
}
|
|
|
|
// FIXME: If we were able to actually fix things along the way,
|
|
// we may have to hunt for the best solution. For now, we don't care.
|
|
|
|
// If there are multiple solutions, try to diagnose an ambiguity.
|
|
if (viable.size() > 1) {
|
|
if (getASTContext().LangOpts.DebugConstraintSolver) {
|
|
auto &log = getASTContext().TypeCheckerDebug->getStream();
|
|
log << "---Ambiguity error: "
|
|
<< viable.size() << " solutions found---\n";
|
|
int i = 0;
|
|
for (auto &solution : viable) {
|
|
log << "---Ambiguous solution #" << i++ << "---\n";
|
|
solution.dump(&TC.Context.SourceMgr, log);
|
|
log << "\n";
|
|
}
|
|
}
|
|
|
|
if (diagnoseAmbiguity(*this, viable)) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Remove the solver state.
|
|
this->solverState = nullptr;
|
|
|
|
// Fall through to produce diagnostics.
|
|
}
|
|
|
|
if (failures.size() == 1) {
|
|
auto &failure = unavoidableFailures.empty()? *failures.begin()
|
|
: **unavoidableFailures.begin();
|
|
|
|
if (diagnoseFailure(*this, failure, expr, false))
|
|
return true;
|
|
}
|
|
|
|
if (getExpressionTooComplex()) {
|
|
TC.diagnose(expr->getLoc(), diag::expression_too_complex).
|
|
highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
// If all else fails, attempt to diagnose the failure by looking through the
|
|
// system's constraints.
|
|
this->diagnoseFailureForExpr(expr);
|
|
|
|
return true;
|
|
}
|