mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
aa68b5adf7
to produce more specific and helpful diagnostics. NFC since it isn't used yet. Swift SVN r30664
3706 lines
127 KiB
C++
3706 lines
127 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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#include "llvm/Support/SaveAndRestore.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 DoesNotHaveInitOnInstance:
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out << getFirstType().getString() << " instance does not have initializers";
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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 FunctionNoEscapeMismatch:
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out << "noescape attribute mismatch " << getFirstType().getString()
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<< " vs. " << getSecondType().getString();
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break;
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case FunctionThrowsMismatch:
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out << "function throws mismatch " << getFirstType().getString() << " vs. "
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<< 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 IsNotMaterializable:
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out << getFirstType().getString() << " is not materializable";
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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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if (auto objectLiteralExpr = dyn_cast<ObjectLiteralExpr>(anchor)) {
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = objectLiteralExpr->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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case ConstraintLocator::CheckedCastOperand:
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if (auto castExpr = dyn_cast<ExplicitCastExpr>(anchor)) {
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = castExpr->getSubExpr();
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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::ClosureResult:
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if (auto CE = dyn_cast<ClosureExpr>(anchor)) {
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if (CE->hasSingleExpressionBody()) {
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = CE->getSingleExpressionBody();
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path = path.slice(1);
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continue;
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}
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}
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break;
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case ConstraintLocator::IfThen:
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if (auto ITE = dyn_cast<IfExpr>(anchor)) {
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = ITE->getThenExpr();
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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::IfElse:
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if (auto ITE = dyn_cast<IfExpr>(anchor)) {
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targetAnchor = nullptr;
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targetPath.clear();
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anchor = ITE->getElseExpr();
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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 identity = dyn_cast<IdentityExpr>(anchor)) {
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anchor = identity->getSubExpr();
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continue;
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}
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if (auto tryExpr = dyn_cast<AnyTryExpr>(anchor)) {
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anchor = tryExpr->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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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.
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declRef = mre->getMember();
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} else if (isa<OverloadedDeclRefExpr>(anchor) ||
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isa<OverloadedMemberRefExpr>(anchor) ||
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isa<UnresolvedDeclRefExpr>(anchor)) {
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// Overloaded and unresolved cases: find the resolved overload.
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auto anchorLocator = cs.getConstraintLocator(anchor);
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if (auto selected = findOvlChoice(anchorLocator)) {
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if (selected->choice.isDecl())
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declRef = getConcreteDeclRefFromOverload(*selected);
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}
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} else if (isa<UnresolvedMemberExpr>(anchor)) {
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// Unresolved member: find the resolved overload.
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auto anchorLocator = cs.getConstraintLocator(
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anchor,
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ConstraintLocator::UnresolvedMember);
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if (auto selected = findOvlChoice(anchorLocator)) {
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if (selected->choice.isDecl())
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declRef = getConcreteDeclRefFromOverload(*selected);
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}
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} else if (auto ctorRef = dyn_cast<OtherConstructorDeclRefExpr>(anchor)) {
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declRef = ctorRef->getDeclRef();
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}
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// If we didn't find the declaration, we're out of luck.
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if (!declRef)
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return ResolvedLocator();
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|
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// Use the declaration and the path to produce a more specific result.
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// FIXME: This is an egregious hack. We'd be far better off
|
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// FIXME: Perform deeper path resolution?
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auto path = locator->getPath();
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Pattern *parameterPattern = nullptr;
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bool impliesFullPattern = false;
|
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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->getElement(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->getElement(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->getNumElements() == 1) {
|
|
parameterPattern = tuple->getElement(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->getNumElements(), tuple2->getNumElements())
|
|
.highlight(range1).highlight(range2);
|
|
return true;
|
|
}
|
|
|
|
case Failure::TupleUnused:
|
|
tc.diagnose(loc, diag::invalid_tuple_element_unused,
|
|
failure.getFirstType(),
|
|
failure.getSecondType())
|
|
.highlight(range1).highlight(range2);
|
|
return true;
|
|
|
|
case Failure::TypesNotConvertible:
|
|
case Failure::TypesNotEqual:
|
|
case Failure::TypesNotSubtypes:
|
|
case Failure::TypesNotConstructible:
|
|
case Failure::FunctionTypesMismatch:
|
|
return false;
|
|
|
|
case Failure::DoesNotHaveMember:
|
|
case Failure::DoesNotHaveNonMutatingMember: {
|
|
if (auto moduleTy = failure.getFirstType()->getAs<ModuleType>()) {
|
|
tc.diagnose(loc, diag::no_member_of_module,
|
|
moduleTy->getModule()->getName(),
|
|
failure.getName())
|
|
.highlight(range1).highlight(range2);
|
|
break;
|
|
}
|
|
|
|
// If the base of this property access is a function that takes an empty
|
|
// argument list, then the most likely problem is that the user wanted to
|
|
// call the function, e.g. in "a.b.c" where they had to write "a.b().c".
|
|
// Produce a specific diagnostic + fixit for this situation.
|
|
auto baseFTy = failure.getFirstType()->getAs<AnyFunctionType>();
|
|
if (baseFTy &&baseFTy->getInput()->isEqual(tc.Context.TheEmptyTupleType)){
|
|
SourceLoc insertLoc = locator->getAnchor()->getEndLoc();
|
|
|
|
if (auto *UDE = dyn_cast<UnresolvedDotExpr>(locator->getAnchor())) {
|
|
tc.diagnose(loc, diag::did_not_call_method, UDE->getName())
|
|
.fixItInsertAfter(insertLoc, "()");
|
|
break;
|
|
}
|
|
|
|
tc.diagnose(loc, diag::did_not_call_function)
|
|
.fixItInsertAfter(insertLoc, "()");
|
|
break;
|
|
}
|
|
|
|
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::DoesNotHaveInitOnInstance: {
|
|
// Diagnose 'super.init', which can only appear inside another initializer,
|
|
// specially.
|
|
auto ctorRef = dyn_cast<UnresolvedConstructorExpr>(locator->getAnchor());
|
|
if (isa<SuperRefExpr>(ctorRef->getSubExpr())) {
|
|
tc.diagnose(loc, diag::super_initializer_not_in_initializer);
|
|
break;
|
|
}
|
|
|
|
// Suggest inserting '.dynamicType' to construct another object of the same
|
|
// dynamic type.
|
|
SourceLoc fixItLoc;
|
|
if (ctorRef) {
|
|
// Place the '.dynamicType' right before the init.
|
|
fixItLoc = ctorRef->getConstructorLoc().getAdvancedLoc(-1);
|
|
}
|
|
|
|
auto diag = tc.diagnose(loc, diag::init_not_instance_member);
|
|
if (fixItLoc.isValid())
|
|
diag.fixItInsert(fixItLoc, ".dynamicType");
|
|
diag.flush();
|
|
|
|
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,
|
|
ConformanceCheckFlags::InExpression,
|
|
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->getElement(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::invalid_force_unwrap,
|
|
failure.getFirstType())
|
|
.highlight(force->getSourceRange())
|
|
.fixItRemove(force->getExclaimLoc());
|
|
|
|
return true;
|
|
}
|
|
|
|
if (auto bind = dyn_cast_or_null<BindOptionalExpr>(anchor)) {
|
|
tc.diagnose(loc, diag::invalid_optional_chain,
|
|
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::IsNotMaterializable: {
|
|
tc.diagnose(loc, diag::cannot_bind_generic_parameter_to_type,
|
|
failure.getFirstType())
|
|
.highlight(range1);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::FunctionNoEscapeMismatch: {
|
|
tc.diagnose(loc, diag::noescape_functiontype_mismatch,
|
|
failure.getSecondType()).highlight(range2);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::FunctionThrowsMismatch: {
|
|
tc.diagnose(loc, diag::throws_functiontype_mismatch,
|
|
failure.getFirstType()->getAs<AnyFunctionType>()->throws(),
|
|
failure.getFirstType(),
|
|
failure.getSecondType()->getAs<AnyFunctionType>()->throws(),
|
|
failure.getSecondType())
|
|
.highlight(range2);
|
|
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();
|
|
}
|
|
|
|
static 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;
|
|
}
|
|
|
|
static 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)
|
|
continue;
|
|
|
|
// 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;
|
|
}
|
|
|
|
/// 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 anchor = simplifyLocatorToAnchor(*CS, constraint->getLocator());
|
|
auto type1 = anchor && anchor->getType() ? anchor->getType() :expr->getType();
|
|
|
|
auto type2 = constraint->getSecondType();
|
|
|
|
if (type1->isEqual(type2))
|
|
if (auto firstType = constraint->getFirstType())
|
|
type1 = firstType;
|
|
|
|
if (auto typeVariableType =
|
|
dyn_cast<TypeVariableType>(type2.getPointer())) {
|
|
|
|
if (typeVariableType->getImpl().
|
|
getRepresentative(nullptr) == typeVariableType) {
|
|
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 if (impl.getLocator()) {
|
|
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.)
|
|
static 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();
|
|
}
|
|
|
|
/// Conveniently unwrap a paren expression, if necessary.
|
|
static Expr *unwrapParenExpr(Expr *e) {
|
|
if (auto parenExpr = dyn_cast<ParenExpr>(e))
|
|
return unwrapParenExpr(parenExpr->getSubExpr());
|
|
|
|
return e;
|
|
}
|
|
|
|
static SmallVector<Type, 4> decomposeArgumentType(Type ty) {
|
|
SmallVector<Type, 4> result;
|
|
|
|
// Assemble the parameter type list.
|
|
if (auto parenType = dyn_cast<ParenType>(ty.getPointer())) {
|
|
result.push_back(parenType->getUnderlyingType());
|
|
} else if (auto tupleType = ty->getAs<TupleType>()) {
|
|
for (auto field : tupleType->getElements())
|
|
result.push_back(field.getType());
|
|
} else {
|
|
result.push_back(ty);
|
|
}
|
|
return result;
|
|
}
|
|
|
|
static std::string getTypeListString(Type type) {
|
|
// Assemble the parameter type list.
|
|
auto tupleType = type->getAs<TupleType>();
|
|
if (!tupleType) {
|
|
if (auto PT = dyn_cast<ParenType>(type.getPointer()))
|
|
type = PT->getUnderlyingType();
|
|
|
|
return "(" + type->getString() + ")";
|
|
}
|
|
|
|
std::string result = "(";
|
|
for (auto field : tupleType->getElements()) {
|
|
if (result.size() != 1)
|
|
result += ", ";
|
|
if (!field.getName().empty()) {
|
|
result += field.getName().str();
|
|
result += ": ";
|
|
}
|
|
|
|
if (!field.isVararg())
|
|
result += field.getType()->getString();
|
|
else {
|
|
result += field.getVarargBaseTy()->getString();
|
|
result += "...";
|
|
}
|
|
}
|
|
result += ")";
|
|
return result;
|
|
}
|
|
|
|
|
|
/// If an UnresolvedDotExpr has been resolved by the constraint system, return
|
|
/// the decl that it references.
|
|
static ValueDecl *findResolvedMemberRef(ConstraintLocator *locator,
|
|
ConstraintSystem &CS) {
|
|
auto *resolvedOverloadSets = CS.getResolvedOverloadSets();
|
|
if (!resolvedOverloadSets) return nullptr;
|
|
|
|
// Search through the resolvedOverloadSets to see if we have a resolution for
|
|
// this member. This is an O(n) search, but only happens when producing an
|
|
// error diagnostic.
|
|
for (auto resolved = resolvedOverloadSets;
|
|
resolved; resolved = resolved->Previous) {
|
|
if (resolved->Locator != locator) continue;
|
|
|
|
// We only handle the simplest decl binding.
|
|
if (resolved->Choice.getKind() != OverloadChoiceKind::Decl)
|
|
return nullptr;
|
|
return resolved->Choice.getDecl();
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
|
|
/// Given an expression that has a non-lvalue type, dig into it until we find
|
|
/// the part of the expression that prevents the entire subexpression from being
|
|
/// mutable. For example, in a sequence like "x.v.v = 42" we want to complain
|
|
/// about "x" being a let property if "v.v" are both mutable.
|
|
///
|
|
/// This returns the base subexpression that looks immutable (or that can't be
|
|
/// analyzed any further) along with a decl extracted from it if we could.
|
|
///
|
|
static std::pair<Expr*, ValueDecl*>
|
|
resolveImmutableBase(Expr *expr, ConstraintSystem &CS) {
|
|
expr = expr->getSemanticsProvidingExpr();
|
|
|
|
// Provide specific diagnostics for assignment to subscripts whose base expr
|
|
// is known to be an rvalue.
|
|
if (auto *SE = dyn_cast<SubscriptExpr>(expr)) {
|
|
// If we found a decl for the subscript, check to see if it is a set-only
|
|
// subscript decl.
|
|
SubscriptDecl *member = nullptr;
|
|
if (SE->hasDecl())
|
|
member = dyn_cast_or_null<SubscriptDecl>(SE->getDecl().getDecl());
|
|
|
|
if (!member) {
|
|
auto loc = CS.getConstraintLocator(SE,ConstraintLocator::SubscriptMember);
|
|
member = dyn_cast_or_null<SubscriptDecl>(findResolvedMemberRef(loc, CS));
|
|
}
|
|
|
|
// If it isn't settable, return it.
|
|
if (member) {
|
|
if (!member->isSettable() ||
|
|
!member->isSetterAccessibleFrom(CS.DC))
|
|
return { expr, member };
|
|
}
|
|
|
|
// If it is settable, then the base must be the problem, recurse.
|
|
return resolveImmutableBase(SE->getBase(), CS);
|
|
}
|
|
|
|
// Look through property references.
|
|
if (auto *UDE = dyn_cast<UnresolvedDotExpr>(expr)) {
|
|
// If we found a decl for the UDE, check it.
|
|
auto loc = CS.getConstraintLocator(UDE, ConstraintLocator::Member);
|
|
auto *member = dyn_cast_or_null<VarDecl>(findResolvedMemberRef(loc, CS));
|
|
|
|
// If the member isn't settable, then it is the problem: return it.
|
|
if (member) {
|
|
if (!member->isSettable(nullptr) ||
|
|
!member->isSetterAccessibleFrom(CS.DC))
|
|
return { expr, member };
|
|
}
|
|
|
|
// If we weren't able to resolve a member or if it is mutable, then the
|
|
// problem must be with the base, recurse.
|
|
return resolveImmutableBase(UDE->getBase(), CS);
|
|
}
|
|
|
|
if (auto *MRE = dyn_cast<MemberRefExpr>(expr)) {
|
|
// If the member isn't settable, then it is the problem: return it.
|
|
if (auto member = dyn_cast<AbstractStorageDecl>(MRE->getMember().getDecl()))
|
|
if (!member->isSettable(nullptr) ||
|
|
!member->isSetterAccessibleFrom(CS.DC))
|
|
return { expr, member };
|
|
|
|
// If we weren't able to resolve a member or if it is mutable, then the
|
|
// problem must be with the base, recurse.
|
|
return resolveImmutableBase(MRE->getBase(), CS);
|
|
}
|
|
|
|
if (auto *DRE = dyn_cast<DeclRefExpr>(expr))
|
|
return { expr, DRE->getDecl() };
|
|
|
|
// Look through x!
|
|
if (auto *FVE = dyn_cast<ForceValueExpr>(expr))
|
|
return resolveImmutableBase(FVE->getSubExpr(), CS);
|
|
|
|
// Look through x?
|
|
if (auto *BOE = dyn_cast<BindOptionalExpr>(expr))
|
|
return resolveImmutableBase(BOE->getSubExpr(), CS);
|
|
|
|
return { expr, nullptr };
|
|
}
|
|
|
|
static void diagnoseSubElementFailure(Expr *destExpr,
|
|
SourceLoc loc,
|
|
ConstraintSystem &CS,
|
|
Diag<StringRef> diagID,
|
|
Diag<Type> unknownDiagID) {
|
|
auto &TC = CS.getTypeChecker();
|
|
|
|
// Walk through the destination expression, resolving what the problem is. If
|
|
// we find a node in the lvalue path that is problematic, this returns it.
|
|
auto immInfo = resolveImmutableBase(destExpr, CS);
|
|
|
|
// Otherwise, we cannot resolve this because the available setter candidates
|
|
// are all mutating and the base must be mutating. If we dug out a
|
|
// problematic decl, we can produce a nice tailored diagnostic.
|
|
if (auto *VD = dyn_cast_or_null<VarDecl>(immInfo.second)) {
|
|
std::string message = "'";
|
|
message += VD->getName().str().str();
|
|
message += "'";
|
|
|
|
if (VD->isImplicit())
|
|
message += " is immutable";
|
|
else if (VD->isLet())
|
|
message += " is a 'let' constant";
|
|
else if (VD->hasAccessorFunctions() && !VD->getSetter())
|
|
message += " is a get-only property";
|
|
else if (!VD->isSetterAccessibleFrom(CS.DC))
|
|
message += " setter is inaccessible";
|
|
else {
|
|
message += " is immutable";
|
|
}
|
|
TC.diagnose(loc, diagID, message)
|
|
.highlight(immInfo.first->getSourceRange());
|
|
|
|
// If this is a simple variable marked with a 'let', emit a note to fixit
|
|
// hint it to 'var'.
|
|
VD->emitLetToVarNoteIfSimple(CS.DC);
|
|
return;
|
|
}
|
|
|
|
// If the underlying expression was a read-only subscript, diagnose that.
|
|
if (auto *SD = dyn_cast_or_null<SubscriptDecl>(immInfo.second)) {
|
|
StringRef message;
|
|
if (!SD->getSetter())
|
|
message = "subscript is get-only";
|
|
else if (!SD->isSetterAccessibleFrom(CS.DC))
|
|
message = "subscript setter is inaccessible";
|
|
else
|
|
message = "subscript is immutable";
|
|
|
|
TC.diagnose(loc, diagID, message)
|
|
.highlight(immInfo.first->getSourceRange());
|
|
return;
|
|
}
|
|
|
|
// If the expression is the result of a call, it is an rvalue, not a mutable
|
|
// lvalue.
|
|
if (auto *AE = dyn_cast<ApplyExpr>(immInfo.first)) {
|
|
std::string name = "call";
|
|
if (isa<PrefixUnaryExpr>(AE) || isa<PostfixUnaryExpr>(AE))
|
|
name = "unary operator";
|
|
else if (isa<BinaryExpr>(AE))
|
|
name = "binary operator";
|
|
else if (isa<CallExpr>(AE))
|
|
name = "function call";
|
|
else if (isa<DotSyntaxCallExpr>(AE) || isa<DotSyntaxBaseIgnoredExpr>(AE))
|
|
name = "method call";
|
|
|
|
if (auto *DRE =
|
|
dyn_cast<DeclRefExpr>(AE->getFn()->getSemanticsProvidingExpr()))
|
|
name = std::string("'") + DRE->getDecl()->getName().str().str() + "'";
|
|
|
|
TC.diagnose(loc, diagID, name + " returns immutable value")
|
|
.highlight(AE->getSourceRange());
|
|
return;
|
|
}
|
|
|
|
TC.diagnose(loc, unknownDiagID, destExpr->getType())
|
|
.highlight(immInfo.first->getSourceRange());
|
|
}
|
|
|
|
namespace {
|
|
/// Each match in an ApplyExpr is evaluated for how close of a match it is.
|
|
/// The result is captured in this enum value, where the earlier entries are
|
|
/// most specific.
|
|
enum CandidateCloseness {
|
|
CC_ExactMatch, // This is a perfect match for the arguments.
|
|
CC_NonLValueInOut, // First argument is inout but no lvalue present.
|
|
CC_OneArgumentMismatch, // All arguments except one match.
|
|
CC_SelfMismatch, // Self argument mismatches.
|
|
CC_ArgumentMismatch, // Argument list mismatch.
|
|
CC_ArgumentCountMismatch, // This candidate has wrong # arguments.
|
|
CC_GeneralMismatch // Something else is wrong.
|
|
};
|
|
|
|
/// This is a candidate for a callee, along with an uncurry level.
|
|
///
|
|
/// The uncurry level specifies how far much of a curried value has already
|
|
/// been applied. For example, in a funcdecl of:
|
|
/// func f(a:Int)(b:Double) -> Int
|
|
/// Uncurry level of 0 indicates that we're looking at the "a" argument, an
|
|
/// uncurry level of 1 indicates that we're looking at the "b" argument.
|
|
struct UncurriedCandidate {
|
|
ValueDecl *decl;
|
|
unsigned level;
|
|
|
|
AnyFunctionType *getUncurriedFunctionType() const {
|
|
auto type = decl->getType();
|
|
|
|
// If this is an operator func decl in a type context, the 'self' isn't
|
|
// actually going to be applied.
|
|
if (auto *fd = dyn_cast<FuncDecl>(decl))
|
|
if (fd->isOperator() && fd->getDeclContext()->isTypeContext())
|
|
type = type->castTo<AnyFunctionType>()->getResult();
|
|
|
|
for (unsigned i = 0, e = level; i != e; ++i) {
|
|
auto funcTy = type->getAs<AnyFunctionType>();
|
|
if (!funcTy) return nullptr;
|
|
type = funcTy->getResult();
|
|
}
|
|
|
|
return type->getAs<AnyFunctionType>();
|
|
}
|
|
|
|
/// Given a function candidate with an uncurry level, return the parameter
|
|
/// type at the specified uncurry level. If there is an error getting to
|
|
/// the specified input, this returns a null Type.
|
|
Type getArgumentType() const {
|
|
if (auto *funcTy = getUncurriedFunctionType())
|
|
return funcTy->getInput();
|
|
return Type();
|
|
}
|
|
|
|
/// Given a function candidate with an uncurry level, return the parameter
|
|
/// type at the specified uncurry level. If there is an error getting to
|
|
/// the specified input, this returns a null Type.
|
|
Type getResultType() const {
|
|
if (auto *funcTy = getUncurriedFunctionType())
|
|
return funcTy->getResult();
|
|
return Type();
|
|
}
|
|
};
|
|
|
|
|
|
/// This struct represents an analyzed function pointer to determine the
|
|
/// candidates that could be called, or the one concrete decl that will be
|
|
/// called if not ambiguous.
|
|
class CalleeCandidateInfo {
|
|
ConstraintSystem *CS;
|
|
public:
|
|
std::string declName;
|
|
|
|
/// This is the list of candidates identified.
|
|
SmallVector<UncurriedCandidate, 4> candidates;
|
|
|
|
/// This tracks how close the match is.
|
|
CandidateCloseness closeness;
|
|
|
|
/// Analyze a function expr and break it into a candidate set. On failure,
|
|
/// this leaves the candidate list empty.
|
|
CalleeCandidateInfo(Expr *Fn, ConstraintSystem *CS) : CS(CS) {
|
|
collectCalleeCandidates(Fn);
|
|
}
|
|
|
|
/// Analyze a locator for a SubscriptExpr for its candidate set.
|
|
CalleeCandidateInfo(ConstraintLocator *locator, ConstraintSystem *CS);
|
|
|
|
typedef const std::function<CandidateCloseness(UncurriedCandidate)>
|
|
&ClosenessPredicate;
|
|
|
|
/// After the candidate list is formed, it can be filtered down to discard
|
|
/// obviously mismatching candidates and compute a "closeness" for the
|
|
/// resultant set.
|
|
void filterList(Type actualArgsType);
|
|
void filterList(ClosenessPredicate predicate);
|
|
|
|
bool empty() const { return candidates.empty(); }
|
|
unsigned size() const { return candidates.size(); }
|
|
UncurriedCandidate operator[](unsigned i) const {
|
|
return candidates[i];
|
|
}
|
|
|
|
/// Given a set of parameter lists from an overload group, and a list of
|
|
/// arguments, emit a diagnostic indicating any partially matching
|
|
/// overloads.
|
|
void suggestPotentialOverloads(StringRef functionName, SourceLoc loc,
|
|
bool isCallExpr = false);
|
|
|
|
private:
|
|
void collectCalleeCandidates(Expr *fnExpr);
|
|
};
|
|
}
|
|
|
|
|
|
/// Given a candidate list, this computes the narrowest closeness to the match
|
|
/// we're looking for and filters out any worse matches. The predicate
|
|
/// indicates how close a given candidate is to the desired match.
|
|
void CalleeCandidateInfo::filterList(ClosenessPredicate predicate) {
|
|
closeness = CC_GeneralMismatch;
|
|
|
|
// If we couldn't find anything, give up.
|
|
if (candidates.empty())
|
|
return;
|
|
|
|
// Now that we have the candidate list, figure out what the best matches from
|
|
// the candidate list are, and remove all the ones that aren't at that level.
|
|
SmallVector<CandidateCloseness, 4> closenessList;
|
|
closenessList.reserve(candidates.size());
|
|
for (auto decl : candidates) {
|
|
closenessList.push_back(predicate(decl));
|
|
closeness = std::min(closeness, closenessList.back());
|
|
}
|
|
|
|
// Now that we know the minimum closeness, remove all the elements that aren't
|
|
// as close.
|
|
unsigned NextElt = 0;
|
|
for (unsigned i = 0, e = candidates.size(); i != e; ++i) {
|
|
// If this decl in the result list isn't a close match, ignore it.
|
|
if (closeness != closenessList[i])
|
|
continue;
|
|
|
|
// Otherwise, preserve it.
|
|
candidates[NextElt++] = candidates[i];
|
|
}
|
|
|
|
candidates.erase(candidates.begin()+NextElt, candidates.end());
|
|
}
|
|
|
|
|
|
/// Determine how close an argument list is to an already decomposed argument
|
|
/// list.
|
|
static CandidateCloseness
|
|
evaluateCloseness(Type candArgListType, ArrayRef<Type> actualArgs) {
|
|
auto candArgs = decomposeArgumentType(candArgListType);
|
|
|
|
// FIXME: This isn't handling varargs, and isn't handling default values
|
|
// either.
|
|
if (actualArgs.size() != candArgs.size()) {
|
|
// If the candidate is varargs, and if there are more arguments specified
|
|
// than required, consider this a general mismatch.
|
|
// TODO: we could catalog the remaining entries if they *do* match up.
|
|
if (auto *TT = candArgListType->getAs<TupleType>()) {
|
|
if (!TT->getElements().empty()) {
|
|
if (TT->getElements().back().isVararg() &&
|
|
actualArgs.size() >= TT->getElements().size()-1)
|
|
return CC_GeneralMismatch;
|
|
}
|
|
}
|
|
|
|
return CC_ArgumentCountMismatch;
|
|
}
|
|
|
|
// Count the number of mismatched arguments.
|
|
unsigned mismatchingArgs = 0;
|
|
for (unsigned i = 0, e = actualArgs.size(); i != e; ++i) {
|
|
// 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.
|
|
if (!actualArgs[i]->getRValueType()->isEqual(candArgs[i]))
|
|
++mismatchingArgs;
|
|
}
|
|
|
|
// If the arguments match up exactly, then we have an exact match. This
|
|
// handles the no-argument cases as well.
|
|
if (mismatchingArgs == 0)
|
|
return CC_ExactMatch;
|
|
|
|
// Check to see if the first argument expects an inout argument, but is not
|
|
// an lvalue.
|
|
if (candArgs[0]->is<InOutType>() && !actualArgs[0]->isLValueType())
|
|
return CC_NonLValueInOut;
|
|
|
|
if (mismatchingArgs == 1)
|
|
return actualArgs.size() != 1 ? CC_OneArgumentMismatch :CC_ArgumentMismatch;
|
|
|
|
// TODO: Keyword argument mismatches.
|
|
|
|
return CC_GeneralMismatch;
|
|
}
|
|
|
|
|
|
void CalleeCandidateInfo::collectCalleeCandidates(Expr *fn) {
|
|
fn = fn->getSemanticsProvidingExpr();
|
|
|
|
// Treat a call to a load of a variable as a call to that variable, it is just
|
|
// the lvalue'ness being removed.
|
|
if (auto load = dyn_cast<LoadExpr>(fn)) {
|
|
if (isa<DeclRefExpr>(load->getSubExpr()))
|
|
return collectCalleeCandidates(load->getSubExpr());
|
|
}
|
|
|
|
if (auto declRefExpr = dyn_cast<DeclRefExpr>(fn)) {
|
|
candidates.push_back({ declRefExpr->getDecl(), 0 });
|
|
declName = declRefExpr->getDecl()->getNameStr().str();
|
|
return;
|
|
}
|
|
|
|
if (auto declRefExpr = dyn_cast<OtherConstructorDeclRefExpr>(fn)) {
|
|
auto decl = declRefExpr->getDecl();
|
|
candidates.push_back({ decl, 0 });
|
|
|
|
if (auto fTy = decl->getType()->getAs<AnyFunctionType>())
|
|
declName = fTy->getInput()->getRValueInstanceType()->getString()+".init";
|
|
else
|
|
declName = "init";
|
|
return;
|
|
}
|
|
|
|
if (auto overloadedDRE = dyn_cast<OverloadedDeclRefExpr>(fn)) {
|
|
for (auto cand : overloadedDRE->getDecls()) {
|
|
candidates.push_back({ cand, 0 });
|
|
}
|
|
|
|
if (!candidates.empty())
|
|
declName = candidates[0].decl->getNameStr().str();
|
|
return;
|
|
}
|
|
|
|
if (auto TE = dyn_cast<TypeExpr>(fn)) {
|
|
// It's always a metatype type, so use the instance type name.
|
|
auto instanceType =TE->getType()->castTo<MetatypeType>()->getInstanceType();
|
|
|
|
// TODO: figure out right value for isKnownPrivate
|
|
if (!instanceType->getAs<TupleType>()) {
|
|
auto ctors = CS->TC.lookupConstructors(CS->DC, instanceType);
|
|
for (auto ctor : ctors)
|
|
candidates.push_back({ ctor, 1 });
|
|
}
|
|
|
|
declName = instanceType->getString();
|
|
return;
|
|
}
|
|
|
|
if (auto *DSBI = dyn_cast<DotSyntaxBaseIgnoredExpr>(fn)) {
|
|
collectCalleeCandidates(DSBI->getRHS());
|
|
return;
|
|
}
|
|
|
|
|
|
if (auto AE = dyn_cast<ApplyExpr>(fn)) {
|
|
collectCalleeCandidates(AE->getFn());
|
|
|
|
// If we found a candidate list with a recursive walk, try adjust the curry
|
|
// level for the applied subexpression in this call.
|
|
if (!candidates.empty()) {
|
|
for (auto &C : candidates)
|
|
C.level += 1;
|
|
return;
|
|
}
|
|
}
|
|
|
|
// Otherwise, we couldn't tell structurally what is going on here, so try to
|
|
// dig something out of the constraint system.
|
|
unsigned uncurryLevel = 0;
|
|
|
|
// The candidate list of an unresolved_dot_expr is the candidate list of the
|
|
// base uncurried by one level, and we refer to the name of the member, not to
|
|
// the name of any base.
|
|
if (auto UDE = dyn_cast<UnresolvedDotExpr>(fn)) {
|
|
declName = UDE->getName().str().str();
|
|
uncurryLevel = 1;
|
|
}
|
|
|
|
// Calls to super.init() are automatically uncurried one level.
|
|
if (auto *UCE = dyn_cast<UnresolvedConstructorExpr>(fn)) {
|
|
uncurryLevel = 1;
|
|
|
|
auto selfTy = UCE->getSubExpr()->getType()->getLValueOrInOutObjectType();
|
|
if (selfTy->hasTypeVariable())
|
|
declName = "init";
|
|
else
|
|
declName = selfTy.getString() + ".init";
|
|
}
|
|
|
|
if (isa<MemberRefExpr>(fn))
|
|
uncurryLevel = 1;
|
|
|
|
// Scan to see if we have a disjunction constraint for this callee.
|
|
for (auto &constraint : CS->getConstraints()) {
|
|
if (constraint.getKind() != ConstraintKind::Disjunction) continue;
|
|
|
|
auto locator = constraint.getLocator();
|
|
if (!locator || locator->getAnchor() != fn) continue;
|
|
|
|
for (auto *bindOverload : constraint.getNestedConstraints()) {
|
|
if (bindOverload->getKind() != ConstraintKind::BindOverload)
|
|
continue;
|
|
auto c = bindOverload->getOverloadChoice();
|
|
if (c.isDecl())
|
|
candidates.push_back({ c.getDecl(), uncurryLevel });
|
|
}
|
|
|
|
// If we found some candidates, then we're done.
|
|
if (candidates.empty()) continue;
|
|
|
|
if (declName.empty())
|
|
declName = candidates[0].decl->getNameStr().str();
|
|
return;
|
|
}
|
|
}
|
|
|
|
/// After the candidate list is formed, it can be filtered down to discard
|
|
/// obviously mismatching candidates and compute a "closeness" for the
|
|
/// resultant set.
|
|
void CalleeCandidateInfo::filterList(Type actualArgsType) {
|
|
// Now that we have the candidate list, figure out what the best matches from
|
|
// the candidate list are, and remove all the ones that aren't at that level.
|
|
auto actualArgs = decomposeArgumentType(actualArgsType);
|
|
filterList([&](UncurriedCandidate candidate) -> CandidateCloseness {
|
|
auto inputType = candidate.getArgumentType();
|
|
// If this isn't a function or isn't valid at this uncurry level, treat it
|
|
// as a general mismatch.
|
|
if (!inputType) return CC_GeneralMismatch;
|
|
return evaluateCloseness(inputType, actualArgs);
|
|
});
|
|
}
|
|
|
|
CalleeCandidateInfo::CalleeCandidateInfo(ConstraintLocator *locator,
|
|
ConstraintSystem *CS) : CS(CS) {
|
|
if (auto decl = findResolvedMemberRef(locator, *CS)) {
|
|
// If the decl is fully resolved, add it.
|
|
candidates.push_back({ decl, 0 });
|
|
} else {
|
|
// Otherwise, look for a disjunction between different candidates.
|
|
for (auto &constraint : CS->getConstraints()) {
|
|
if (constraint.getLocator() != locator) continue;
|
|
|
|
// Okay, we found our constraint. Check to see if it is a disjunction.
|
|
if (constraint.getKind() != ConstraintKind::Disjunction) continue;
|
|
|
|
for (auto *bindOverload : constraint.getNestedConstraints()) {
|
|
auto c = bindOverload->getOverloadChoice();
|
|
if (c.isDecl())
|
|
candidates.push_back({ c.getDecl(), 0 });
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/// Given a set of parameter lists from an overload group, and a list of
|
|
/// arguments, emit a diagnostic indicating any partially matching overloads.
|
|
void CalleeCandidateInfo::
|
|
suggestPotentialOverloads(StringRef functionName, SourceLoc loc,
|
|
bool isCallExpr) {
|
|
|
|
// If the candidate list is has no near matches to the actual types, don't
|
|
// print out a candidate list, it will just be noise.
|
|
if (closeness == CC_GeneralMismatch) {
|
|
|
|
// FIXME: This is arbitrary, we should use the same policy for operators.
|
|
if (!isCallExpr)
|
|
return;
|
|
}
|
|
|
|
std::string suggestionText = "";
|
|
std::set<std::string> dupes;
|
|
|
|
// FIXME2: For (T,T) & (Self, Self), emit this as two candidates, one using
|
|
// the LHS and one using the RHS type for T's.
|
|
for (auto cand : candidates) {
|
|
Type paramListType;
|
|
|
|
if (auto *SD = dyn_cast<SubscriptDecl>(cand.decl)) {
|
|
paramListType = SD->getIndicesType();
|
|
} else {
|
|
paramListType = cand.getArgumentType();
|
|
}
|
|
if (paramListType.isNull())
|
|
continue;
|
|
|
|
// If we've already seen this (e.g. decls overridden on the result type),
|
|
// ignore this one.
|
|
auto name = getTypeListString(paramListType);
|
|
if (!dupes.insert(name).second)
|
|
continue;
|
|
|
|
if (!suggestionText.empty())
|
|
suggestionText += ", ";
|
|
suggestionText += name;
|
|
}
|
|
|
|
if (suggestionText.empty())
|
|
return;
|
|
|
|
if (dupes.size() == 1) {
|
|
CS->TC.diagnose(loc, diag::suggest_expected_match, suggestionText);
|
|
} else {
|
|
CS->TC.diagnose(loc, diag::suggest_partial_overloads, functionName,
|
|
suggestionText);
|
|
}
|
|
}
|
|
|
|
/// Flags that can be used to control name lookup.
|
|
enum TCCFlags {
|
|
/// Don't force the subexpression to resolve to a specific type. If the
|
|
/// subexpr is ambiguous, don't diagnose an error.
|
|
/// FIXME: this should always be on.
|
|
TCC_AllowUnresolved = 0x01,
|
|
|
|
/// Allow the result of the subexpression to be an lvalue. If this is not
|
|
/// specified, any lvalue will be forced to be loaded into an rvalue.
|
|
TCC_AllowLValue = 0x02
|
|
};
|
|
|
|
typedef OptionSet<TCCFlags> TCCOptions;
|
|
|
|
inline TCCOptions operator|(TCCFlags flag1, TCCFlags flag2) {
|
|
return TCCOptions(flag1) | flag2;
|
|
}
|
|
|
|
|
|
namespace {
|
|
/// If a constraint system fails to converge on a solution for a given
|
|
/// expression, this class can produce a reasonable diagnostic for the failure
|
|
/// by analyzing the remnants of the failed constraint system. (Specifically,
|
|
/// left-over inactive, active and failed constraints.)
|
|
/// This class does not tune its diagnostics for a specific expression kind,
|
|
/// for that, you'll want to use an instance of the FailureDiagnosis class.
|
|
class FailureDiagnosis :public ASTVisitor<FailureDiagnosis, /*exprresult*/bool>{
|
|
friend class ASTVisitor<FailureDiagnosis, /*exprresult*/bool>;
|
|
|
|
Expr *expr = nullptr;
|
|
ConstraintSystem *const CS;
|
|
|
|
// Specific constraint kinds used, in conjunction with the expression node,
|
|
// to determine the appropriate diagnostic.
|
|
Constraint *conversionConstraint = nullptr;
|
|
Constraint *overloadConstraint = nullptr;
|
|
Constraint *valueMemberConstraint = nullptr;
|
|
Constraint *argumentConstraint = nullptr;
|
|
Constraint *conformanceConstraint = nullptr;
|
|
|
|
public:
|
|
|
|
FailureDiagnosis(Expr *expr, ConstraintSystem *CS);
|
|
|
|
template<typename ...ArgTypes>
|
|
InFlightDiagnostic diagnose(ArgTypes &&...Args) {
|
|
return CS->TC.diagnose(std::forward<ArgTypes>(Args)...);
|
|
}
|
|
|
|
/// Attempt to diagnose a failure without taking into account the specific
|
|
/// kind of expression that could not be type checked.
|
|
bool diagnoseGeneralFailure();
|
|
|
|
/// Unless we've already done this, retypecheck the specified child of the
|
|
/// current expression on its own, without including any contextual
|
|
/// constraints or the parent expr nodes. This is more likely to succeed than
|
|
/// type checking the original expression.
|
|
///
|
|
/// This mention may only be used on immediate children of the current expr
|
|
/// node, because ClosureExpr parameters need to be treated specially.
|
|
///
|
|
/// This can return a new expression (for e.g. when a UnresolvedDeclRef gets
|
|
/// resolved) and returns null when the subexpression fails to typecheck.
|
|
///
|
|
Expr *typeCheckChildIndependently(Expr *subExpr, Type convertType = Type(),
|
|
TCCOptions options = TCCOptions());
|
|
|
|
Type getTypeOfTypeCheckedChildIndependently(Expr *subExpr,
|
|
TCCOptions options = TCCOptions()) {
|
|
auto e = typeCheckChildIndependently(subExpr, Type(), options);
|
|
return e ? e->getType() : Type();
|
|
}
|
|
|
|
/// This is the same as typeCheckChildIndependently, but works on an arbitrary
|
|
/// subexpression of the current node because it handles ClosureExpr parents
|
|
/// of the specified node.
|
|
Expr *typeCheckArbitrarySubExprIndependently(Expr *subExpr,
|
|
Type convertType = Type(),
|
|
TCCOptions options = TCCOptions());
|
|
|
|
/// Special magic to handle inout exprs and tuples in argument lists.
|
|
Expr *typeCheckArgumentChildIndependently(Expr *argExpr,
|
|
const CalleeCandidateInfo &candidates);
|
|
|
|
/// Attempt to diagnose a specific failure from the info we've collected from
|
|
/// the failed constraint system.
|
|
bool diagnoseFailure();
|
|
|
|
private:
|
|
|
|
/// Attempt to produce a diagnostic for a mismatch between an expression's
|
|
/// type and its assumed contextual type.
|
|
bool diagnoseContextualConversionError(Type exprResultType);
|
|
|
|
/// Produce a diagnostic for a general member-lookup failure (irrespective of
|
|
/// the exact expression kind).
|
|
bool diagnoseGeneralValueMemberFailure();
|
|
|
|
/// Produce a diagnostic for a general overload resolution failure
|
|
/// (irrespective of the exact expression kind).
|
|
bool diagnoseGeneralOverloadFailure();
|
|
|
|
/// Produce a diagnostic for a general conversion failure (irrespective of the
|
|
/// exact expression kind).
|
|
bool diagnoseGeneralConversionFailure();
|
|
|
|
bool visitExpr(Expr *E);
|
|
|
|
bool visitForceValueExpr(ForceValueExpr *FVE);
|
|
bool visitBindOptionalExpr(BindOptionalExpr *BOE);
|
|
|
|
bool visitBinaryExpr(BinaryExpr *BE);
|
|
bool visitUnaryExpr(ApplyExpr *AE);
|
|
bool visitPrefixUnaryExpr(PrefixUnaryExpr *PUE) {
|
|
return visitUnaryExpr(PUE);
|
|
}
|
|
bool visitPostfixUnaryExpr(PostfixUnaryExpr *PUE) {
|
|
return visitUnaryExpr(PUE);
|
|
}
|
|
|
|
bool visitSubscriptExpr(SubscriptExpr *SE);
|
|
bool visitCallExpr(CallExpr *CE);
|
|
bool visitAssignExpr(AssignExpr *AE);
|
|
bool visitInOutExpr(InOutExpr *IOE);
|
|
bool visitCoerceExpr(CoerceExpr *CE);
|
|
bool visitForcedCheckedCastExpr(ForcedCheckedCastExpr *FCCE);
|
|
bool visitIfExpr(IfExpr *IE);
|
|
bool visitRebindSelfInConstructorExpr(RebindSelfInConstructorExpr *E);
|
|
bool visitClosureExpr(ClosureExpr *CE);
|
|
};
|
|
} // end anonymous namespace.
|
|
|
|
/// Return true if this constraint is a conversion or requirement between two
|
|
/// types.
|
|
static bool isConversionConstraint(const Constraint *C) {
|
|
switch (C->getKind()) {
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
case ConstraintKind::Subtype:
|
|
return true;
|
|
|
|
default:
|
|
return false;
|
|
}
|
|
}
|
|
|
|
|
|
|
|
FailureDiagnosis::FailureDiagnosis(Expr *expr, ConstraintSystem *cs)
|
|
: expr(expr), CS(cs) {
|
|
assert(expr && CS);
|
|
|
|
// If the constraint system had a failure constraint, it takes precedence over
|
|
// other random constraints in the system.
|
|
if (auto constraint = CS->failedConstraint) {
|
|
if (constraint->getKind() == ConstraintKind::BindOverload) {
|
|
overloadConstraint = CS->failedConstraint;
|
|
} else if (isConversionConstraint(constraint))
|
|
conversionConstraint = CS->failedConstraint;
|
|
}
|
|
|
|
Constraint *fallbackConstraint = nullptr;
|
|
Constraint *disjunctionConversionConstraint = nullptr;
|
|
for (auto & constraintRef : CS->getConstraints()) {
|
|
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 ((!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()) &&
|
|
isConversionConstraint(constraint)) {
|
|
conversionConstraint = 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 FailureDiagnosis::diagnoseGeneralValueMemberFailure() {
|
|
|
|
if (!valueMemberConstraint) return false;
|
|
|
|
assert(valueMemberConstraint->getKind() == ConstraintKind::ValueMember ||
|
|
valueMemberConstraint->getKind() ==
|
|
ConstraintKind::UnresolvedValueMember);
|
|
|
|
auto memberName = valueMemberConstraint->getMember().getBaseName();
|
|
|
|
// Get the referenced expression from the failed constraint.
|
|
auto anchor = expr;
|
|
if (auto locator = valueMemberConstraint->getLocator()) {
|
|
anchor = simplifyLocatorToAnchor(*CS, locator);
|
|
if (!anchor)
|
|
anchor = locator->getAnchor();
|
|
}
|
|
|
|
// Retypecheck the anchor type, which is the base of the member expression.
|
|
anchor = typeCheckArbitrarySubExprIndependently(anchor);
|
|
if (!anchor) return true;
|
|
|
|
auto type = anchor->getType();
|
|
|
|
if (typeIsNotSpecialized(type)) {
|
|
diagnose(anchor->getLoc(), diag::could_not_find_member, memberName)
|
|
.highlight(anchor->getSourceRange());
|
|
} else {
|
|
diagnose(anchor->getLoc(), diag::could_not_find_member_type,
|
|
type, memberName)
|
|
.highlight(anchor->getSourceRange());
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseGeneralOverloadFailure() {
|
|
|
|
// If this is a return expression with available conversion constraints,
|
|
// we can produce a better diagnostic by pointing out the return expression
|
|
// conversion failure.
|
|
if (expr->isReturnExpr() && (conversionConstraint || argumentConstraint))
|
|
if (diagnoseGeneralConversionFailure())
|
|
return true;
|
|
|
|
// In the absense of a better conversion constraint failure, point out the
|
|
// inability to find an appropriate overload.
|
|
if (!overloadConstraint)
|
|
return false;
|
|
|
|
|
|
auto overloadChoice = overloadConstraint->getOverloadChoice();
|
|
std::string overloadName = overloadChoice.getDecl()->getNameStr();
|
|
|
|
if (auto *CD = dyn_cast<ConstructorDecl>(overloadChoice.getDecl()))
|
|
if (auto *SD = CD->getImplicitSelfDecl())
|
|
overloadName = SD->getType()->getInOutObjectType().getString() + ".init";
|
|
|
|
// Get the referenced expression from the failed constraint.
|
|
auto anchor = expr;
|
|
if (auto locator = overloadConstraint->getLocator()) {
|
|
anchor = simplifyLocatorToAnchor(*CS, locator);
|
|
if (!anchor)
|
|
anchor = locator->getAnchor();
|
|
}
|
|
|
|
// The anchor for the constraint is almost always an OverloadedDeclRefExpr.
|
|
// Look at the parent node in the AST to find the Apply to give a better
|
|
// diagnostic.
|
|
Expr *call = expr->getParentMap()[anchor];
|
|
// Ignore parens around the callee.
|
|
while (call && (isa<IdentityExpr>(call) || isa<AnyTryExpr>(call)))
|
|
call = expr->getParentMap()[call];
|
|
|
|
// Do some sanity checking based on the call: e.g. make sure we're invoking
|
|
// the overloaded decl, not using it as an argument.
|
|
Type argType;
|
|
if (auto *AE = dyn_cast_or_null<ApplyExpr>(call)) {
|
|
if (AE->getFn()->getSemanticsProvidingExpr() == anchor) {
|
|
// Type check the argument list independently to try to get a concrete
|
|
// type (ignoring context).
|
|
auto argExpr = typeCheckArbitrarySubExprIndependently(AE->getArg(),
|
|
Type(),
|
|
TCC_AllowUnresolved);
|
|
if (!argExpr) return true;
|
|
|
|
argType = argExpr->getType();
|
|
}
|
|
}
|
|
|
|
if (argType.isNull() || argType->is<TypeVariableType>()) {
|
|
diagnose(anchor->getLoc(), diag::cannot_find_appropriate_overload,
|
|
overloadName)
|
|
.highlight(anchor->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
|
|
// Otherwise, we have a good grasp on what is going on: we have a call of an
|
|
// unresolve overload set. Try to dig out the candidates.
|
|
auto apply = cast<ApplyExpr>(call);
|
|
CalleeCandidateInfo calleeInfo(apply->getFn(), CS);
|
|
calleeInfo.filterList(argType);
|
|
|
|
|
|
// A common error is to apply an operator that only has an inout LHS (e.g. +=)
|
|
// to non-lvalues (e.g. a local let). Produce a nice diagnostic for this
|
|
// case.
|
|
if (calleeInfo.closeness == CC_NonLValueInOut) {
|
|
Expr *firstArg = apply->getArg();
|
|
if (auto *tuple = dyn_cast<TupleExpr>(firstArg))
|
|
if (tuple->getNumElements())
|
|
firstArg = tuple->getElement(0);
|
|
|
|
diagnoseSubElementFailure(firstArg, apply->getLoc(), *CS,
|
|
diag::cannot_apply_lvalue_binop_to_subelement,
|
|
diag::cannot_apply_lvalue_binop_to_rvalue);
|
|
return true;
|
|
}
|
|
|
|
|
|
// If we have an argument list (i.e., a scalar, or a non-zero-element tuple)
|
|
// then diagnose with some specificity about the arguments.
|
|
if (isa<TupleExpr>(apply->getArg()) &&
|
|
cast<TupleExpr>(apply->getArg())->getNumElements() == 0) {
|
|
// Emit diagnostics that say "no arguments".
|
|
diagnose(apply->getFn()->getLoc(), diag::cannot_call_with_no_params,
|
|
overloadName, /*isInitializer*/false)
|
|
.highlight(apply->getSourceRange());
|
|
} else {
|
|
diagnose(apply->getFn()->getLoc(), diag::cannot_call_with_params,
|
|
overloadName, getTypeListString(argType), /*isInitializer*/false)
|
|
.highlight(apply->getSourceRange());
|
|
}
|
|
|
|
calleeInfo.suggestPotentialOverloads(overloadName, apply->getLoc());
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseGeneralConversionFailure() {
|
|
|
|
// Otherwise, if we have a conversion constraint, use that as the basis for
|
|
// the diagnostic.
|
|
if (!conversionConstraint && !argumentConstraint)
|
|
return false;
|
|
|
|
auto constraint =
|
|
argumentConstraint ? argumentConstraint : conversionConstraint;
|
|
|
|
if (conformanceConstraint) {
|
|
if (conformanceConstraint->getTypeVariables().size() <
|
|
constraint->getTypeVariables().size()) {
|
|
constraint = conformanceConstraint;
|
|
}
|
|
}
|
|
|
|
auto anchor = expr;
|
|
if (auto locator = constraint->getLocator()) {
|
|
anchor = simplifyLocatorToAnchor(*CS, locator);
|
|
if (!anchor)
|
|
anchor = locator->getAnchor();
|
|
}
|
|
|
|
std::pair<Type, Type> types = getBoundTypesFromConstraint(CS, anchor,
|
|
constraint);
|
|
|
|
if (argumentConstraint) {
|
|
diagnose(anchor->getLoc(), diag::could_not_convert_argument, types.first)
|
|
.highlight(anchor->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
// 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>()) {
|
|
diagnose(anchor->getLoc(), diag::single_expression_conformance_failure,
|
|
types.first)
|
|
.highlight(anchor->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
Type fromType;
|
|
if (auto sub = typeCheckArbitrarySubExprIndependently(anchor))
|
|
fromType = sub->getType();
|
|
else
|
|
fromType = types.first.getPointer();
|
|
|
|
fromType = fromType->getRValueType();
|
|
|
|
auto toType = CS->getContextualType(anchor);
|
|
if (!toType)
|
|
toType = types.second.getPointer();
|
|
|
|
// If the second type is a type variable, the expression itself is
|
|
// ambiguous.
|
|
if (fromType->is<UnboundGenericType>() || toType->is<TypeVariableType>() ||
|
|
(fromType->is<TypeVariableType>() && toType->is<ProtocolType>())) {
|
|
auto diagID = diag::type_of_expression_is_ambiguous;
|
|
if (isa<ClosureExpr>(anchor))
|
|
diagID = diag::cannot_infer_closure_type;
|
|
|
|
diagnose(anchor->getLoc(), diagID)
|
|
.highlight(anchor->getSourceRange());
|
|
|
|
if (auto *CE = dyn_cast<ClosureExpr>(anchor)) {
|
|
if (!CE->hasSingleExpressionBody() &&
|
|
!CE->hasExplicitResultType() &&
|
|
!CE->getBody()->getElements().empty()) {
|
|
diagnose(CE->getLoc(),
|
|
diag::mult_stmt_closures_require_explicit_result);
|
|
}
|
|
}
|
|
|
|
|
|
return true;
|
|
}
|
|
|
|
// Special case the diagnostic for a function result-type mismatch.
|
|
if (anchor->isReturnExpr()) {
|
|
if (toType->isVoid()) {
|
|
diagnose(anchor->getLoc(), diag::cannot_return_value_from_void_func);
|
|
return true;
|
|
}
|
|
|
|
diagnose(anchor->getLoc(), diag::cannot_convert_to_return_type,
|
|
fromType, toType)
|
|
.highlight(anchor->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
auto failureKind = Failure::FailureKind::TypesNotConvertible;
|
|
switch (constraint->getKind()) {
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
diagnose(anchor->getLoc(), diag::type_does_not_conform,
|
|
fromType, toType)
|
|
.highlight(expr->getSourceRange());
|
|
return true;
|
|
|
|
case ConstraintKind::Subtype:
|
|
failureKind = Failure::FailureKind::TypesNotSubtypes;
|
|
break;
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
failureKind = Failure::FailureKind::TypesNotConvertible;
|
|
break;
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
default: break;
|
|
}
|
|
|
|
diagnose(anchor->getLoc(), diag::invalid_relation,
|
|
failureKind - Failure::TypesNotEqual,
|
|
fromType, toType)
|
|
.highlight(anchor->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::diagnoseGeneralFailure() {
|
|
|
|
return diagnoseGeneralValueMemberFailure() ||
|
|
diagnoseGeneralOverloadFailure() ||
|
|
diagnoseGeneralConversionFailure();
|
|
}
|
|
|
|
namespace {
|
|
class ExprTypeSaver {
|
|
llvm::DenseMap<Expr*, Type> ExprTypes;
|
|
llvm::DenseMap<TypeLoc*, std::pair<Type, bool>> TypeLocTypes;
|
|
llvm::DenseMap<Pattern*, Type> PatternTypes;
|
|
public:
|
|
|
|
void save(Expr *E) {
|
|
struct TypeSaver : public ASTWalker {
|
|
ExprTypeSaver *TS;
|
|
TypeSaver(ExprTypeSaver *TS) : TS(TS) {}
|
|
|
|
std::pair<bool, Expr *> walkToExprPre(Expr *expr) override {
|
|
TS->ExprTypes[expr] = expr->getType();
|
|
return { true, expr };
|
|
}
|
|
|
|
bool walkToTypeLocPre(TypeLoc &TL) override {
|
|
if (TL.getTypeRepr() && TL.getType())
|
|
TS->TypeLocTypes[&TL] = { TL.getType(), TL.wasValidated() };
|
|
return true;
|
|
}
|
|
|
|
std::pair<bool, Pattern*> walkToPatternPre(Pattern *P) override {
|
|
if (P->hasType())
|
|
TS->PatternTypes[P] = P->getType();
|
|
return { true, P };
|
|
}
|
|
|
|
// Don't walk into statements. This handles the BraceStmt in
|
|
// non-single-expr closures, so we don't walk into their body.
|
|
std::pair<bool, Stmt *> walkToStmtPre(Stmt *S) override {
|
|
return { false, S };
|
|
}
|
|
};
|
|
|
|
E->walk(TypeSaver(this));
|
|
}
|
|
|
|
void restore(Expr *E) {
|
|
for (auto exprElt : ExprTypes)
|
|
exprElt.first->setType(exprElt.second);
|
|
|
|
for (auto typelocElt : TypeLocTypes)
|
|
typelocElt.first->setType(typelocElt.second.first,
|
|
typelocElt.second.second);
|
|
|
|
for (auto patternElt : PatternTypes)
|
|
patternElt.first->setType(patternElt.second);
|
|
|
|
// Done, don't do redundant work on destruction.
|
|
ExprTypes.clear();
|
|
TypeLocTypes.clear();
|
|
PatternTypes.clear();
|
|
}
|
|
|
|
// On destruction, if a type got wiped out, reset it from null to its
|
|
// original type. This is helpful because type checking a subexpression
|
|
// can lead to replacing the nodes in that subexpression. However, the
|
|
// failed ConstraintSystem still has locators pointing to the old nodes,
|
|
// and if expr-specific diagnostics fail to turn up anything useful to say,
|
|
// we go digging through failed constraints, and expect their locators to
|
|
// still be meaningful.
|
|
~ExprTypeSaver() {
|
|
for (auto exprElt : ExprTypes)
|
|
if (!exprElt.first->getType())
|
|
exprElt.first->setType(exprElt.second);
|
|
|
|
for (auto typelocElt : TypeLocTypes)
|
|
if (!typelocElt.first->getType())
|
|
typelocElt.first->setType(typelocElt.second.first,
|
|
typelocElt.second.second);
|
|
|
|
for (auto patternElt : PatternTypes)
|
|
if (!patternElt.first->hasType())
|
|
patternElt.first->setType(patternElt.second);
|
|
}
|
|
};
|
|
}
|
|
|
|
/// \brief "Nullify" an expression tree's type data, to make it suitable for
|
|
/// re-typecheck operations.
|
|
static void eraseTypeData(Expr *expr) {
|
|
/// Private class to "cleanse" an expression tree of types. This is done in the
|
|
/// case of a typecheck failure, where we may want to re-typecheck partially-
|
|
/// typechecked subexpressions in a context-free manner.
|
|
class TypeNullifier : public ASTWalker {
|
|
public:
|
|
std::pair<bool, Expr *> walkToExprPre(Expr *expr) override {
|
|
// Preserve module expr type data to prevent further lookups.
|
|
if (auto *declRef = dyn_cast<DeclRefExpr>(expr))
|
|
if (isa<ModuleDecl>(declRef->getDecl()))
|
|
return { false, expr };
|
|
|
|
// Don't strip type info off OtherConstructorDeclRefExpr, because CSGen
|
|
// doesn't know how to reconstruct it.
|
|
if (isa<OtherConstructorDeclRefExpr>(expr))
|
|
return { false, expr };
|
|
|
|
// If a literal has a Builtin.Int or Builtin.FP type on it already,
|
|
// then sema has already expanded out a call to
|
|
// Init.init(<builtinliteral>)
|
|
// and we don't want it to make
|
|
// Init.init(Init.init(<builtinliteral>))
|
|
// preserve the type info to prevent this from happening.
|
|
if (isa<IntegerLiteralExpr>(expr) || isa<FloatLiteralExpr>(expr) ||
|
|
isa<BooleanLiteralExpr>(expr))
|
|
if (expr->getType()->is<BuiltinType>())
|
|
return { false, expr };
|
|
|
|
expr->setType(nullptr);
|
|
return { true, expr };
|
|
}
|
|
|
|
// If we find a TypeLoc (e.g. in an as? expr) with a type variable, rewrite
|
|
// it.
|
|
bool walkToTypeLocPre(TypeLoc &TL) override {
|
|
if (TL.getTypeRepr())
|
|
TL.setType(Type(), /*was validated*/false);
|
|
return true;
|
|
}
|
|
|
|
std::pair<bool, Pattern*> walkToPatternPre(Pattern *pattern) override {
|
|
pattern->setType(nullptr);
|
|
return { true, pattern };
|
|
}
|
|
|
|
// Don't walk into statements. This handles the BraceStmt in
|
|
// non-single-expr closures, so we don't walk into their body.
|
|
std::pair<bool, Stmt *> walkToStmtPre(Stmt *S) override {
|
|
return { false, S };
|
|
}
|
|
};
|
|
|
|
expr->walk(TypeNullifier());
|
|
}
|
|
|
|
|
|
/// Erase an expression tree's open existentials after a re-typecheck operation.
|
|
///
|
|
/// This is done in the case of a typecheck failure, after we re-typecheck
|
|
/// partially-typechecked subexpressions in a context-free manner.
|
|
///
|
|
static void eraseOpenedExistentials(Expr *&expr) {
|
|
|
|
class ExistentialEraser : public ASTWalker {
|
|
llvm::SmallDenseMap<OpaqueValueExpr *, Expr *, 4> OpenExistentials;
|
|
|
|
public:
|
|
std::pair<bool, Expr *> walkToExprPre(Expr *expr) override {
|
|
if (auto openExistentialExpr = dyn_cast<OpenExistentialExpr>(expr)) {
|
|
auto archetypeVal = openExistentialExpr->getOpaqueValue();
|
|
auto base = openExistentialExpr->getExistentialValue();
|
|
bool inserted = OpenExistentials.insert({archetypeVal, base}).second;
|
|
assert(inserted);
|
|
(void) inserted;
|
|
return { true, openExistentialExpr->getSubExpr() };
|
|
}
|
|
|
|
if (auto opaqueValueExpr = dyn_cast<OpaqueValueExpr>(expr)) {
|
|
auto value = OpenExistentials.find(opaqueValueExpr);
|
|
assert(value != OpenExistentials.end());
|
|
return { true, value->second };
|
|
}
|
|
|
|
return { true, expr };
|
|
}
|
|
|
|
Expr *walkToExprPost(Expr *expr) override {
|
|
Type type = expr->getType();
|
|
if (!type || !type->hasOpenedExistential())
|
|
return expr;
|
|
|
|
type = type.transform([&](Type type) -> Type {
|
|
if (auto archetype = type->getAs<ArchetypeType>())
|
|
if (auto existentialType = archetype->getOpenedExistentialType())
|
|
return existentialType;
|
|
|
|
return type;
|
|
});
|
|
expr->setType(type);
|
|
|
|
return expr;
|
|
}
|
|
|
|
// Don't walk into statements. This handles the BraceStmt in
|
|
// non-single-expr closures, so we don't walk into their body.
|
|
std::pair<bool, Stmt *> walkToStmtPre(Stmt *S) override {
|
|
return { false, S };
|
|
}
|
|
};
|
|
|
|
expr->walk(ExistentialEraser());
|
|
}
|
|
|
|
|
|
/// Unless we've already done this, retypecheck the specified subexpression on
|
|
/// its own, without including any contextual constraints or parent expr
|
|
/// nodes. This is more likely to succeed than type checking the original
|
|
/// expression.
|
|
///
|
|
/// This can return a new expression (for e.g. when a UnresolvedDeclRef gets
|
|
/// resolved) and returns null when the subexpression fails to typecheck.
|
|
Expr *FailureDiagnosis::typeCheckChildIndependently(Expr *subExpr,
|
|
Type convertType,
|
|
TCCOptions options) {
|
|
// Track if this sub-expression is currently being diagnosed.
|
|
if (Expr *res = CS->TC.exprIsBeingDiagnosed(subExpr))
|
|
return res;
|
|
|
|
// FIXME: expressions are never removed from this set.
|
|
CS->TC.addExprForDiagnosis(subExpr, subExpr);
|
|
|
|
if (isa<ClosureExpr>(subExpr))
|
|
options |= TCC_AllowUnresolved;
|
|
|
|
// These expression types can never be checked without their enclosing
|
|
// context, so don't try - it would just make bogus diagnostics.
|
|
if (isa<NilLiteralExpr>(subExpr) ||
|
|
|
|
// A '_' is only allowed on the LHS of an assignment, so we can't descend
|
|
// past the AssignExpr. This is a problem below because we're not
|
|
// allowing ambiguous solutions for subexprs, and thus the code below is
|
|
// forced to diagnose "discard_expr_outside_of_assignment". This should
|
|
// really allow ambiguous expressions and diagnose it only in MiscDiags.
|
|
isa<DiscardAssignmentExpr>(subExpr))
|
|
return subExpr;
|
|
|
|
// TupleExpr often contains things that cannot be typechecked without
|
|
// context (usually from a parameter list), but we do it if they already have
|
|
// an unspecialized type.
|
|
// FIXME: This is a total hack.
|
|
if ((isa<TupleExpr>(subExpr) ||
|
|
|
|
// InOutExpr needs contextual information otherwise we complain about it
|
|
// not being in an argument context.
|
|
isa<InOutExpr>(subExpr)) &&
|
|
!typeIsNotSpecialized(subExpr->getType()))
|
|
return subExpr;
|
|
|
|
|
|
ExprTypeSaver SavedTypeData;
|
|
SavedTypeData.save(subExpr);
|
|
|
|
// Store off the sub-expression, in case a new one is provided via the
|
|
// type check operation.
|
|
Expr *preCheckedExpr = subExpr;
|
|
|
|
eraseTypeData(subExpr);
|
|
|
|
// Disable structural checks, because we know that the overall expression
|
|
// has type constraint problems, and we don't want to know about any
|
|
// syntactic issues in a well-typed subexpression (which might be because
|
|
// the context is missing).
|
|
TypeCheckExprOptions TCEOptions = TypeCheckExprFlags::DisableStructuralChecks;
|
|
|
|
// Claim that the result is discarded to preserve the lvalue type of
|
|
// the expression.
|
|
if (options.contains(TCC_AllowLValue))
|
|
TCEOptions |= TypeCheckExprFlags::IsDiscarded;
|
|
|
|
if (options.contains(TCC_AllowUnresolved) && !convertType)
|
|
TCEOptions |= TypeCheckExprFlags::AllowUnresolvedTypeVariables;
|
|
|
|
bool hadError = CS->TC.typeCheckExpression(subExpr, CS->DC, convertType,
|
|
/*FIXME*/CTP_Unused, TCEOptions);
|
|
|
|
// This is a terrible hack to get around the fact that typeCheckExpression()
|
|
// might change subExpr to point to a new OpenExistentialExpr. In that case,
|
|
// since the caller passed subExpr by value here, they would be left
|
|
// holding on to an expression containing open existential types but
|
|
// no OpenExistentialExpr, which breaks invariants enforced by the
|
|
// ASTChecker.
|
|
eraseOpenedExistentials(subExpr);
|
|
|
|
// If recursive type checking failed, then an error was emitted. Return
|
|
// null to indicate this to the caller.
|
|
if (hadError)
|
|
return nullptr;
|
|
|
|
// If we type checked the result but failed to get a usable output from it,
|
|
// just pretend as though nothing happened.
|
|
if (subExpr->getType()->is<ErrorType>()) {
|
|
subExpr = preCheckedExpr;
|
|
SavedTypeData.restore(subExpr);
|
|
}
|
|
|
|
CS->TC.addExprForDiagnosis(preCheckedExpr, subExpr);
|
|
return subExpr;
|
|
}
|
|
|
|
/// This is the same as typeCheckChildIndependently, but works on an arbitrary
|
|
/// subexpression of the current node because it handles ClosureExpr parents
|
|
/// of the specified node.
|
|
Expr *FailureDiagnosis::
|
|
typeCheckArbitrarySubExprIndependently(Expr *subExpr, Type convertType,
|
|
TCCOptions options) {
|
|
if (subExpr == expr)
|
|
return typeCheckChildIndependently(subExpr, convertType, options);
|
|
|
|
// Construct a parent map for the expr tree we're investigating.
|
|
auto parentMap = expr->getParentMap();
|
|
|
|
ClosureExpr *NearestClosure = nullptr;
|
|
|
|
// Walk the parents of the specified expression, handling any ClosureExprs.
|
|
for (Expr *node = parentMap[subExpr]; node && node != expr;
|
|
node = parentMap[node]) {
|
|
auto *CE = dyn_cast<ClosureExpr>(node);
|
|
if (!CE) continue;
|
|
|
|
// Keep track of the innermost closure we see that we're jumping into.
|
|
if (!NearestClosure)
|
|
NearestClosure = CE;
|
|
|
|
// If we have a ClosureExpr parent of the specified node, check to make sure
|
|
// none of its arguments are type variables. If so, these type variables
|
|
// would be accessible to name lookup of the subexpression and may thus leak
|
|
// in. Reset them to null types for safe measures.
|
|
CE->getParams()->forEachVariable([&](VarDecl *VD) {
|
|
if (VD->getType()->hasTypeVariable() || VD->getType()->is<ErrorType>())
|
|
VD->overwriteType(Type());
|
|
});
|
|
}
|
|
|
|
// When we're type checking a single-expression closure, we need to reset the
|
|
// DeclContext to this closure for the recursive type checking. Otherwise,
|
|
// if there is a closure in the subexpression, we can violate invariants.
|
|
auto newDC = NearestClosure ? NearestClosure : CS->DC;
|
|
llvm::SaveAndRestore<DeclContext*> SavedDC(CS->DC, newDC);
|
|
|
|
// Otherwise, we're ok to type check the subexpr.
|
|
return typeCheckChildIndependently(subExpr, convertType, options);
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::diagnoseContextualConversionError(Type exprType) {
|
|
// If we don't have a type for the expression afterall, there is nothing
|
|
// we can diagnose.
|
|
if (exprType->is<TypeVariableType>())
|
|
return false;
|
|
|
|
|
|
// Try to find the contextual type in a variety of ways.
|
|
Type contextualType = CS->getContextualType(expr);
|
|
|
|
Constraint *foundConstraint = nullptr;
|
|
|
|
auto checkConstraint = [&](Constraint *C) {
|
|
// Ignore non-conversion constraints.
|
|
if (!isConversionConstraint(C)) return;
|
|
|
|
// If we already found a favored constraint, don't replace it.
|
|
if (foundConstraint && foundConstraint->isFavored())
|
|
return;
|
|
|
|
// Ignore conversion constraints that aren't on the root expression.
|
|
if (!C->getLocator() || C->getLocator()->getAnchor() != expr)
|
|
return;
|
|
|
|
// Don't take a constraint that won't tell us anything.
|
|
if (typeIsNotSpecialized(C->getSecondType()))
|
|
return;
|
|
|
|
foundConstraint = C;
|
|
};
|
|
|
|
// Check the failed constraint, if present.
|
|
if (!contextualType) {
|
|
if (CS->failedConstraint)
|
|
checkConstraint(CS->failedConstraint);
|
|
|
|
// Scan through all of the inactive constraints as well.
|
|
for (auto &constraint : CS->getConstraints())
|
|
checkConstraint(&constraint);
|
|
}
|
|
|
|
// If we found a conversion constraint, it provides the destination type.
|
|
if (foundConstraint) {
|
|
contextualType = foundConstraint->getSecondType();
|
|
|
|
// The contextual type relates to the overall expression, but may be
|
|
// describing only part of the type. Dive into the overall type to narrow
|
|
// it down based on the locator path.
|
|
for (auto &elt : foundConstraint->getLocator()->getPath()) {
|
|
switch (elt.getKind()) {
|
|
case ConstraintLocator::FunctionArgument:
|
|
if (auto FTy = exprType->getAs<AnyFunctionType>())
|
|
exprType = FTy->getInput();
|
|
else
|
|
return false;
|
|
break;
|
|
case ConstraintLocator::FunctionResult:
|
|
if (auto FTy = exprType->getAs<AnyFunctionType>())
|
|
exprType = FTy->getResult();
|
|
else
|
|
return false;
|
|
break;
|
|
default:
|
|
// Don't know how to process this path element yet. Don't emit a
|
|
// warpo diagnostic.
|
|
return false;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!contextualType || typeIsNotSpecialized(contextualType))
|
|
return false;
|
|
|
|
if (exprType->isEqual(contextualType))
|
|
return false;
|
|
|
|
// If this is conversion failure due to a return statement with an argument
|
|
// that cannot be coerced to the result type of the function, emit a
|
|
// specific error.
|
|
if (expr->isReturnExpr()) {
|
|
if (contextualType->isVoid()) {
|
|
diagnose(expr->getLoc(), diag::cannot_return_value_from_void_func)
|
|
.highlight(expr->getSourceRange());
|
|
} else {
|
|
diagnose(expr->getLoc(), diag::cannot_convert_to_return_type,
|
|
exprType, contextualType)
|
|
.highlight(expr->getSourceRange());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
|
|
// If the destination type is a protocol, then use conformsToProtocol to
|
|
// produce a more specific diagnostic.
|
|
if (auto *PT = contextualType->getAs<ProtocolType>()) {
|
|
if (!CS->TC.conformsToProtocol(exprType, PT->getDecl(), CS->DC,
|
|
ConformanceCheckFlags::InExpression,
|
|
nullptr, expr->getLoc()))
|
|
return true;
|
|
}
|
|
|
|
|
|
auto failureKind = Failure::FailureKind::TypesNotConvertible;
|
|
if (foundConstraint) {
|
|
switch (foundConstraint->getKind()) {
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
diagnose(expr->getLoc(), diag::type_does_not_conform,
|
|
exprType, contextualType)
|
|
.highlight(expr->getSourceRange());
|
|
return true;
|
|
|
|
case ConstraintKind::Subtype:
|
|
failureKind = Failure::FailureKind::TypesNotSubtypes;
|
|
break;
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
failureKind = Failure::FailureKind::TypesNotConvertible;
|
|
break;
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
default: break;
|
|
}
|
|
}
|
|
|
|
diagnose(expr->getLoc(), diag::invalid_relation,
|
|
failureKind - Failure::FailureKind::TypesNotEqual,
|
|
exprType, contextualType)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
/// When an assignment to an expression is detected and the destination is
|
|
/// invalid, emit a detailed error about the condition.
|
|
void ConstraintSystem::diagnoseAssignmentFailure(Expr *dest, Type destTy,
|
|
SourceLoc equalLoc) {
|
|
auto &TC = getTypeChecker();
|
|
|
|
// Diagnose obvious assignments to literals.
|
|
if (isa<LiteralExpr>(dest->getSemanticsProvidingExpr())) {
|
|
TC.diagnose(equalLoc, diag::cannot_assign_to_literal);
|
|
return;
|
|
}
|
|
|
|
Diag<StringRef> diagID;
|
|
if (isa<DeclRefExpr>(dest))
|
|
diagID = diag::assignment_lhs_is_immutable_variable;
|
|
else if (isa<ForceValueExpr>(dest))
|
|
diagID = diag::assignment_bang_has_immutable_subcomponent;
|
|
else if (isa<UnresolvedDotExpr>(dest) || isa<MemberRefExpr>(dest))
|
|
diagID = diag::assignment_lhs_is_immutable_property;
|
|
else if (isa<SubscriptExpr>(dest))
|
|
diagID = diag::assignment_subscript_has_immutable_base;
|
|
else {
|
|
diagID = diag::assignment_lhs_is_immutable_variable;
|
|
}
|
|
|
|
diagnoseSubElementFailure(dest, equalLoc, *this, diagID,
|
|
diag::assignment_lhs_not_lvalue);
|
|
}
|
|
|
|
|
|
/// Special magic to handle inout exprs and tuples in argument lists.
|
|
Expr *FailureDiagnosis::
|
|
typeCheckArgumentChildIndependently(Expr *argExpr,
|
|
const CalleeCandidateInfo &candidates) {
|
|
// Grab one of the candidates (if present) and get its input list to help
|
|
// identify operators that have implicit inout arguments.
|
|
Type exampleInputType;
|
|
if (!candidates.empty())
|
|
exampleInputType = candidates[0].getArgumentType();
|
|
|
|
// FIXME: This should all just be a matter of getting type type of the
|
|
// sub-expression, but this doesn't work well when typeCheckChildIndependently
|
|
// is over-conservative w.r.t. TupleExprs.
|
|
if (auto *TE = dyn_cast<TupleExpr>(argExpr)) {
|
|
// Get the simplified type of each element and rebuild the aggregate.
|
|
SmallVector<TupleTypeElt, 4> resultEltTys;
|
|
SmallVector<Expr*, 4> resultElts;
|
|
|
|
TupleType *exampleInputTuple = nullptr;
|
|
if (exampleInputType)
|
|
exampleInputTuple = exampleInputType->getAs<TupleType>();
|
|
|
|
for (unsigned i = 0, e = TE->getNumElements(); i != e; i++) {
|
|
TCCOptions options;
|
|
if (exampleInputTuple && i < exampleInputTuple->getNumElements() &&
|
|
exampleInputTuple->getElementType(i)->is<InOutType>())
|
|
options |= TCC_AllowLValue;
|
|
|
|
auto elExpr = typeCheckChildIndependently(TE->getElement(i), Type(), options);
|
|
if (!elExpr) return nullptr; // already diagnosed.
|
|
|
|
resultElts.push_back(elExpr);
|
|
resultEltTys.push_back({elExpr->getType(), TE->getElementName(i)});
|
|
}
|
|
|
|
auto TT = TupleType::get(resultEltTys, CS->getASTContext());
|
|
return TupleExpr::create(CS->getASTContext(), TE->getLParenLoc(),
|
|
resultElts, TE->getElementNames(),
|
|
TE->getElementNameLocs(),
|
|
TE->getRParenLoc(), TE->hasTrailingClosure(),
|
|
TE->isImplicit(), TT);
|
|
}
|
|
|
|
TCCOptions options;
|
|
if (exampleInputType && exampleInputType->is<InOutType>())
|
|
options |= TCC_AllowLValue;
|
|
|
|
return typeCheckChildIndependently(unwrapParenExpr(argExpr), Type(), options);
|
|
}
|
|
|
|
bool FailureDiagnosis::visitBinaryExpr(BinaryExpr *binop) {
|
|
CalleeCandidateInfo calleeInfo(binop->getFn(), CS);
|
|
assert(!calleeInfo.candidates.empty() && "unrecognized binop function kind");
|
|
|
|
auto checkedArgExpr = typeCheckArgumentChildIndependently(binop->getArg(),
|
|
calleeInfo);
|
|
if (!checkedArgExpr) return true;
|
|
|
|
// Pre-checking can turn (T,U) into a TypeExpr. That's an artifact
|
|
// of independent type-checking; just use the standard diagnostics
|
|
// paths.
|
|
auto argExpr = dyn_cast<TupleExpr>(checkedArgExpr);
|
|
if (!argExpr) return visitExpr(binop);
|
|
|
|
auto argTupleType = argExpr->getType()->castTo<TupleType>();
|
|
calleeInfo.filterList(argTupleType);
|
|
|
|
// Otherwise, whatever the result type of the call happened to be must not
|
|
// have been what we were looking for - diagnose this as a conversion
|
|
// failure.
|
|
if (calleeInfo.closeness == CC_ExactMatch)
|
|
return diagnoseGeneralConversionFailure();
|
|
|
|
// A common error is to apply an operator that only has an inout LHS (e.g. +=)
|
|
// to non-lvalues (e.g. a local let). Produce a nice diagnostic for this
|
|
// case.
|
|
if (calleeInfo.closeness == CC_NonLValueInOut) {
|
|
diagnoseSubElementFailure(argExpr->getElement(0), binop->getLoc(), *CS,
|
|
diag::cannot_apply_lvalue_binop_to_subelement,
|
|
diag::cannot_apply_lvalue_binop_to_rvalue);
|
|
return true;
|
|
}
|
|
|
|
auto argType1 = argTupleType->getElementType(0)->getRValueType();
|
|
auto argType2 = argTupleType->getElementType(1)->getRValueType();
|
|
std::string overloadName = calleeInfo[0].decl->getNameStr();
|
|
assert(!overloadName.empty());
|
|
if (!argType1->isEqual(argType2)) {
|
|
diagnose(binop->getLoc(), diag::cannot_apply_binop_to_args,
|
|
overloadName, argType1, argType2)
|
|
.highlight(argExpr->getElement(0)->getSourceRange())
|
|
.highlight(argExpr->getElement(1)->getSourceRange());
|
|
} else {
|
|
diagnose(binop->getLoc(), diag::cannot_apply_binop_to_same_args,
|
|
overloadName, argType1)
|
|
.highlight(argExpr->getElement(0)->getSourceRange())
|
|
.highlight(argExpr->getElement(1)->getSourceRange());
|
|
}
|
|
|
|
calleeInfo.suggestPotentialOverloads(overloadName, binop->getLoc());
|
|
return true;
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::visitUnaryExpr(ApplyExpr *applyExpr) {
|
|
assert(expr->getKind() == ExprKind::PostfixUnary ||
|
|
expr->getKind() == ExprKind::PrefixUnary);
|
|
|
|
CalleeCandidateInfo calleeInfo(applyExpr->getFn(), CS);
|
|
assert(!calleeInfo.candidates.empty() && "unrecognized unop function kind");
|
|
|
|
auto argExpr = typeCheckArgumentChildIndependently(applyExpr->getArg(),
|
|
calleeInfo);
|
|
if (!argExpr) return true;
|
|
|
|
auto argType = argExpr->getType();
|
|
calleeInfo.filterList(argType);
|
|
|
|
if (calleeInfo.closeness == CC_ExactMatch) {
|
|
// Otherwise, whatever the result type of the call happened to be must not
|
|
// have been what we were looking for.
|
|
auto resultTy = getTypeOfTypeCheckedChildIndependently(applyExpr);
|
|
if (!resultTy)
|
|
return true;
|
|
|
|
if (typeIsNotSpecialized(resultTy))
|
|
resultTy = calleeInfo[0].getResultType();
|
|
|
|
diagnose(applyExpr->getLoc(), diag::result_type_no_match, resultTy)
|
|
.highlight(applyExpr->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
// A common error is to apply an operator that only has inout forms (e.g. ++)
|
|
// to non-lvalues (e.g. a local let). Produce a nice diagnostic for this
|
|
// case.
|
|
if (calleeInfo.closeness == CC_NonLValueInOut) {
|
|
// Diagnose the case when the failure.
|
|
diagnoseSubElementFailure(argExpr, applyExpr->getFn()->getLoc(), *CS,
|
|
diag::cannot_apply_lvalue_unop_to_subelement,
|
|
diag::cannot_apply_lvalue_unop_to_rvalue);
|
|
return true;
|
|
}
|
|
|
|
std::string overloadName = calleeInfo[0].decl->getNameStr();
|
|
assert(!overloadName.empty());
|
|
diagnose(argExpr->getLoc(), diag::cannot_apply_unop_to_arg, overloadName,
|
|
argType);
|
|
|
|
calleeInfo.suggestPotentialOverloads(overloadName, argExpr->getLoc());
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::visitSubscriptExpr(SubscriptExpr *SE) {
|
|
// See if the subscript got resolved.
|
|
auto locator =
|
|
CS->getConstraintLocator(SE, ConstraintLocator::SubscriptMember);
|
|
CalleeCandidateInfo calleeInfo(locator, CS);
|
|
|
|
auto indexExpr = typeCheckArgumentChildIndependently(SE->getIndex(),
|
|
calleeInfo);
|
|
if (!indexExpr) return true;
|
|
|
|
auto baseExpr = typeCheckChildIndependently(SE->getBase());
|
|
if (!baseExpr) return true;
|
|
|
|
auto indexType = indexExpr->getType();
|
|
auto baseType = baseExpr->getType();
|
|
|
|
auto decomposedIndexType = decomposeArgumentType(indexType);
|
|
calleeInfo.filterList([&](UncurriedCandidate cand) -> CandidateCloseness
|
|
{
|
|
// Classify how close this match is. Non-subscript decls don't match.
|
|
auto *SD = dyn_cast<SubscriptDecl>(cand.decl);
|
|
if (!SD) return CC_GeneralMismatch;
|
|
|
|
// Check to make sure the base expr type is convertible to the expected base
|
|
// type.
|
|
auto selfConstraint = CC_ExactMatch;
|
|
auto instanceTy =
|
|
SD->getGetter()->getImplicitSelfDecl()->getType()->getInOutObjectType();
|
|
if (!typeIsNotSpecialized(baseType) &&
|
|
!CS->TC.isConvertibleTo(baseType, instanceTy, CS->DC)) {
|
|
selfConstraint = CC_SelfMismatch;
|
|
}
|
|
|
|
// Explode out multi-index subscripts to find the best match.
|
|
return std::max(evaluateCloseness(SD->getIndicesType(),decomposedIndexType),
|
|
selfConstraint);
|
|
});
|
|
|
|
// TODO: Is there any reason to check for CC_NonLValueInOut here?
|
|
|
|
if (calleeInfo.closeness == CC_ExactMatch) {
|
|
// Otherwise, the return type of the subscript happened to not have been
|
|
// what we were looking for.
|
|
auto resultTy = getTypeOfTypeCheckedChildIndependently(SE);
|
|
if (!resultTy)
|
|
return true;
|
|
|
|
if (!typeIsNotSpecialized(resultTy)) {
|
|
// If we got a strong type back, then we know what the subscript produced.
|
|
} else if (calleeInfo.size() == 1) {
|
|
// If we have one candidate, the result must be what that candidate
|
|
// produced.
|
|
resultTy = calleeInfo[0].getResultType();
|
|
} else {
|
|
diagnose(SE->getLoc(), diag::result_type_no_match_ambiguous)
|
|
.highlight(SE->getSourceRange());
|
|
calleeInfo.suggestPotentialOverloads("subscript", SE->getLoc());
|
|
return true;
|
|
}
|
|
|
|
// Only one choice.
|
|
diagnose(SE->getLoc(), diag::result_type_no_match, resultTy)
|
|
.highlight(SE->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
// If the closes matches all mismatch on self, we either have something that
|
|
// cannot be subscripted, or an ambiguity.
|
|
if (calleeInfo.closeness == CC_SelfMismatch) {
|
|
diagnose(SE->getLoc(), diag::cannot_subscript_base, baseType)
|
|
.highlight(SE->getBase()->getSourceRange());
|
|
// FIXME: Should suggest overload set, but we're not ready for that until
|
|
// it points to candidates and identifies the self type in the diagnostic.
|
|
//calleeInfo.suggestPotentialOverloads("subscript", SE->getLoc());
|
|
return true;
|
|
}
|
|
|
|
diagnose(SE->getLoc(), diag::cannot_subscript_with_index,
|
|
baseType, indexType);
|
|
|
|
calleeInfo.suggestPotentialOverloads("subscript", SE->getLoc());
|
|
return true;
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::visitCallExpr(CallExpr *callExpr) {
|
|
// Type check the function subexpression to resolve a type for it if possible.
|
|
auto fnExpr = typeCheckChildIndependently(callExpr->getFn(), Type(),
|
|
TCC_AllowUnresolved);
|
|
if (!fnExpr) return true;
|
|
|
|
CalleeCandidateInfo calleeInfo(fnExpr, CS);
|
|
|
|
// If we resolved a concrete expression for the callee, and it has
|
|
// non-function/non-metatype type, then we cannot call it!
|
|
auto fnType = fnExpr->getType()->getRValueType();
|
|
|
|
if (!typeIsNotSpecialized(fnType) &&
|
|
!fnType->is<AnyFunctionType>() && !fnType->is<MetatypeType>()) {
|
|
diagnose(callExpr->getArg()->getStartLoc(),
|
|
diag::cannot_call_non_function_value, fnExpr->getType())
|
|
.highlight(fnExpr->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
#if 0
|
|
Type argType; // Type of the argument list, if knowable.
|
|
if (auto FTy = fnType->getAs<AnyFunctionType>())
|
|
if (!typeIsNotSpecialized(FTy->getInput()))
|
|
argType = FTy->getInput();
|
|
#endif
|
|
|
|
|
|
// Get the expression result of type checking the arguments to the call
|
|
// independently, so we have some idea of what we're working with.
|
|
auto argExpr = typeCheckArgumentChildIndependently(callExpr->getArg(),
|
|
calleeInfo);
|
|
if (!argExpr)
|
|
return true; // already diagnosed.
|
|
|
|
calleeInfo.filterList(argExpr->getType());
|
|
|
|
// If we found an exact match, this must be a problem with a conversion from
|
|
// the result of the call to the expected type. Diagnose this as a conversion
|
|
// failure.
|
|
if (calleeInfo.closeness == CC_ExactMatch)
|
|
return diagnoseGeneralFailure();
|
|
|
|
|
|
bool isInitializer = isa<TypeExpr>(fnExpr);
|
|
auto overloadName = calleeInfo.declName;
|
|
|
|
std::string argString = getTypeListString(argExpr->getType());
|
|
|
|
// If we couldn't get the name of the callee, then it must be something of a
|
|
// more complex "value of function type".
|
|
if (overloadName.empty()) {
|
|
// The most common unnamed value of closure type is a ClosureExpr, so
|
|
// special case it.
|
|
if (auto CE = dyn_cast<ClosureExpr>(fnExpr->getSemanticsProvidingExpr())) {
|
|
if (typeIsNotSpecialized(fnType))
|
|
diagnose(argExpr->getStartLoc(), diag::cannot_invoke_closure, argString)
|
|
.highlight(fnExpr->getSourceRange());
|
|
else
|
|
diagnose(argExpr->getStartLoc(), diag::cannot_invoke_closure_type,
|
|
fnType, argString)
|
|
.highlight(fnExpr->getSourceRange());
|
|
|
|
// If this is a multi-statement closure with no explicit result type, emit
|
|
// a note to clue the developer in.
|
|
if (!CE->hasSingleExpressionBody() &&
|
|
!CE->hasExplicitResultType() &&
|
|
!CE->getBody()->getElements().empty()) {
|
|
diagnose(fnExpr->getLoc(),
|
|
diag::mult_stmt_closures_require_explicit_result);
|
|
}
|
|
|
|
} else if (typeIsNotSpecialized(fnType)) {
|
|
diagnose(argExpr->getStartLoc(), diag::cannot_call_function_value,
|
|
argString)
|
|
.highlight(fnExpr->getSourceRange());
|
|
} else {
|
|
diagnose(argExpr->getStartLoc(), diag::cannot_call_value_of_function_type,
|
|
fnType, argString)
|
|
.highlight(fnExpr->getSourceRange());
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
// If we have an argument list (i.e., a scalar, or a non-zero-element tuple)
|
|
// then diagnose with some specificity about the arguments.
|
|
if (isa<TupleExpr>(argExpr) &&
|
|
cast<TupleExpr>(argExpr)->getNumElements() == 0) {
|
|
// Emit diagnostics that say "no arguments".
|
|
diagnose(fnExpr->getLoc(), diag::cannot_call_with_no_params,
|
|
overloadName, isInitializer);
|
|
} else {
|
|
diagnose(fnExpr->getLoc(), diag::cannot_call_with_params,
|
|
overloadName, argString, isInitializer);
|
|
}
|
|
|
|
// Did the user intend on invoking a different overload?
|
|
calleeInfo.suggestPotentialOverloads(overloadName, fnExpr->getLoc(),
|
|
/*isCallExpr*/true);
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::visitAssignExpr(AssignExpr *assignExpr) {
|
|
// Diagnose obvious assignments to literals.
|
|
if (isa<LiteralExpr>(assignExpr->getDest()->getSemanticsProvidingExpr())) {
|
|
diagnose(assignExpr->getLoc(), diag::cannot_assign_to_literal);
|
|
return true;
|
|
}
|
|
|
|
// If the source type is already an error type, we've already posted an error.
|
|
auto srcExpr = typeCheckChildIndependently(assignExpr->getSrc());
|
|
if (!srcExpr) return true;
|
|
|
|
auto destExpr = typeCheckChildIndependently(assignExpr->getDest(), Type(),
|
|
TCC_AllowLValue);
|
|
if (!destExpr) return true;
|
|
|
|
auto destType = destExpr->getType();
|
|
auto srcType = srcExpr->getType();
|
|
|
|
// If the result type is a non-lvalue, then we are failing because it is
|
|
// immutable and that's not a great thing to assign to.
|
|
if (!destType->isLValueType()) {
|
|
CS->diagnoseAssignmentFailure(destExpr, destType, assignExpr->getLoc());
|
|
return true;
|
|
}
|
|
|
|
diagnose(srcExpr->getLoc(), diag::cannot_assign_values, srcType,
|
|
destType->getRValueType());
|
|
return true;
|
|
}
|
|
|
|
bool FailureDiagnosis::visitInOutExpr(InOutExpr *IOE) {
|
|
auto subExpr = typeCheckChildIndependently(IOE->getSubExpr(), Type(),
|
|
TCC_AllowLValue);
|
|
|
|
auto subExprType = subExpr->getType();
|
|
|
|
// The common cause is that the operand is not an lvalue.
|
|
if (!subExprType->isLValueType()) {
|
|
diagnoseSubElementFailure(subExpr, IOE->getLoc(), *CS,
|
|
diag::cannot_pass_rvalue_inout_subelement,
|
|
diag::cannot_pass_rvalue_inout);
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::visitCoerceExpr(CoerceExpr *CE) {
|
|
Expr *subExpr = typeCheckChildIndependently(CE->getSubExpr());
|
|
if (!subExpr) return true;
|
|
Type subType = subExpr->getType();
|
|
|
|
std::pair<Type, Type> conversionTypes(nullptr, nullptr);
|
|
if (conversionConstraint &&
|
|
conversionConstraint->getKind() == ConstraintKind::ExplicitConversion &&
|
|
conversionConstraint->getLocator()->getAnchor() == expr) {
|
|
conversionTypes = getBoundTypesFromConstraint(CS, CE, conversionConstraint);
|
|
} else {
|
|
conversionTypes.first = subType->getLValueOrInOutObjectType();
|
|
conversionTypes.second = CE->getType();
|
|
}
|
|
|
|
if (conversionTypes.first && conversionTypes.second) {
|
|
diagnose(CE->getLoc(), diag::invalid_relation,
|
|
Failure::TypesNotConvertible - Failure::TypesNotEqual,
|
|
conversionTypes.first, conversionTypes.second)
|
|
.highlight(CE->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::
|
|
visitForcedCheckedCastExpr(ForcedCheckedCastExpr *FCE) {
|
|
Expr *subExpr = typeCheckChildIndependently(FCE->getSubExpr());
|
|
if (!subExpr) return true;
|
|
|
|
Type subType = subExpr->getType();
|
|
|
|
std::pair<Type, Type> conversionTypes(nullptr, nullptr);
|
|
if (conversionConstraint &&
|
|
conversionConstraint->getKind() == ConstraintKind::CheckedCast &&
|
|
conversionConstraint->getLocator()->getAnchor() == expr) {
|
|
conversionTypes = getBoundTypesFromConstraint(CS, FCE,
|
|
conversionConstraint);
|
|
} else {
|
|
conversionTypes.first = subType->getLValueOrInOutObjectType();
|
|
conversionTypes.second = FCE->getType();
|
|
}
|
|
|
|
if (conversionTypes.first && conversionTypes.second) {
|
|
diagnose(FCE->getLoc(), diag::invalid_relation,
|
|
Failure::TypesNotConvertible - Failure::TypesNotEqual,
|
|
conversionTypes.first, conversionTypes.second)
|
|
.highlight(FCE->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::visitForceValueExpr(ForceValueExpr *FVE) {
|
|
auto argExpr = typeCheckChildIndependently(FVE->getSubExpr());
|
|
if (!argExpr) return true;
|
|
auto argType = argExpr->getType();
|
|
|
|
// If the subexpression type checks as a non-optional type, then that is the
|
|
// error. Produce a specific diagnostic about this.
|
|
if (argType->getOptionalObjectType().isNull()) {
|
|
diagnose(FVE->getLoc(), diag::invalid_force_unwrap, argType)
|
|
.fixItRemove(FVE->getExclaimLoc())
|
|
.highlight(FVE->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::visitBindOptionalExpr(BindOptionalExpr *BOE) {
|
|
auto argExpr = typeCheckChildIndependently(BOE->getSubExpr());
|
|
if (!argExpr) return true;
|
|
auto argType = argExpr->getType();
|
|
|
|
// If the subexpression type checks as a non-optional type, then that is the
|
|
// error. Produce a specific diagnostic about this.
|
|
if (argType->getOptionalObjectType().isNull()) {
|
|
diagnose(BOE->getQuestionLoc(), diag::invalid_optional_chain, argType)
|
|
.highlight(BOE->getSourceRange())
|
|
.fixItRemove(BOE->getQuestionLoc());
|
|
return true;
|
|
}
|
|
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::visitIfExpr(IfExpr *IE) {
|
|
// Check all of the subexpressions independently.
|
|
auto condExpr = typeCheckChildIndependently(IE->getCondExpr());
|
|
if (!condExpr) return true;
|
|
auto trueExpr = typeCheckChildIndependently(IE->getThenExpr());
|
|
if (!trueExpr) return true;
|
|
|
|
auto falseExpr = typeCheckChildIndependently(IE->getElseExpr());
|
|
if (!falseExpr) return true;
|
|
|
|
// If the condition wasn't of boolean type, diagnose the problem.
|
|
auto booleanType = CS->TC.getProtocol(IE->getQuestionLoc(),
|
|
KnownProtocolKind::BooleanType);
|
|
if (!booleanType) return true;
|
|
|
|
if (!CS->TC.conformsToProtocol(condExpr->getType(), booleanType, CS->DC,
|
|
ConformanceCheckFlags::InExpression,
|
|
nullptr, condExpr->getLoc()))
|
|
return true;
|
|
|
|
// Otherwise, the true/false result types must not be matching.
|
|
diagnose(IE->getColonLoc(), diag::if_expr_cases_mismatch,
|
|
trueExpr->getType(), falseExpr->getType())
|
|
.highlight(trueExpr->getSourceRange())
|
|
.highlight(falseExpr->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::
|
|
visitRebindSelfInConstructorExpr(RebindSelfInConstructorExpr *E) {
|
|
// Don't walk the children for this node, it leads to multiple diagnostics
|
|
// because of how sema injects this node into the type checker.
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::visitClosureExpr(ClosureExpr *CE) {
|
|
// If this is a complex leaf closure, give up.
|
|
if (!CE->hasSingleExpressionBody())
|
|
return diagnoseGeneralFailure();
|
|
|
|
// ClosureExprs are likely to get some clever handling in the future, but for
|
|
// now we need to defend against type variables from our constraint system
|
|
// leaking into recursive constraints systems formed when checking the body
|
|
// of the closure. These typevars come into them when the body does name
|
|
// lookups against the parameter decls.
|
|
//
|
|
// Handle this by rewriting the arguments to Type(). CSGen has special
|
|
// handling for ParamDecls from closure arguments with null types.
|
|
//
|
|
// TODO: If there is a partial type available for the closure, we should apply
|
|
// whatever information we have about it to the paramdecls.
|
|
CE->getParams()->forEachVariable([&](VarDecl *VD) {
|
|
if (VD->getType()->hasTypeVariable() || VD->getType()->is<ErrorType>())
|
|
VD->overwriteType(Type());
|
|
});
|
|
|
|
// When we're type checking a single-expression closure, we need to reset the
|
|
// DeclContext to this closure for the recursive type checking. Otherwise,
|
|
// if there is a closure in the subexpression, we can violate invariants.
|
|
{
|
|
llvm::SaveAndRestore<DeclContext*> SavedDC(CS->DC, CE);
|
|
if (!typeCheckChildIndependently(CE->getSingleExpressionBody()))
|
|
return true;
|
|
}
|
|
|
|
// Otherwise, produce a generic error.
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
bool FailureDiagnosis::visitExpr(Expr *E) {
|
|
// Check each of our immediate children to see if any of them are
|
|
// independently invalid.
|
|
bool errorInSubExpr = false;
|
|
|
|
E->forEachChildExpr([&](Expr *Child) {
|
|
// If we already found an error, stop checking.
|
|
if (errorInSubExpr) return;
|
|
|
|
// Otherwise this subexpr is an error if type checking it produces an error.
|
|
errorInSubExpr |= !typeCheckChildIndependently(Child);
|
|
});
|
|
|
|
// If any of the children were errors, we're done.
|
|
if (errorInSubExpr)
|
|
return true;
|
|
|
|
// Otherwise, produce a more generic error.
|
|
return diagnoseGeneralFailure();
|
|
}
|
|
|
|
|
|
bool FailureDiagnosis::diagnoseFailure() {
|
|
assert(CS && expr);
|
|
|
|
|
|
// Our general approach is to do a depth first traversal of the broken
|
|
// expression tree, type checking as we go. If we find a subtree that cannot
|
|
// be type checked on its own (even to an incomplete type) then that is where
|
|
// we focus our attention. If we do find a type, we use it to check for
|
|
// contextual type mismatches.
|
|
|
|
// If we're at the top-level of the expression fresh in from a client whose
|
|
// constraint system failed, check to see if we can type check the expression
|
|
// by itself. If not, then we'll get a more specific failure in the
|
|
// subexpression. If so, then we know it must be some conversion constraint
|
|
// binding the result of the expression to a type that fails.
|
|
if (!CS->TC.exprIsBeingDiagnosed(expr)) {
|
|
// Type check the expression independently of any contextual constraints.
|
|
auto subExprTy = getTypeOfTypeCheckedChildIndependently(expr);
|
|
|
|
// If it failed an diagnosed something, then we're done.
|
|
if (!subExprTy) return true;
|
|
|
|
// Otherwise, it is almost certainly a contextual constraint mismatch, dig
|
|
// one out.
|
|
if (diagnoseContextualConversionError(subExprTy))
|
|
return true;
|
|
}
|
|
|
|
return visit(expr);
|
|
}
|
|
|
|
/// Given a specific expression and the remnants of the failed constraint
|
|
/// system, produce a specific diagnostic.
|
|
bool ConstraintSystem::diagnoseFailureForExpr(Expr *expr) {
|
|
if (auto *RB = dyn_cast<RebindSelfInConstructorExpr>(expr))
|
|
expr = RB->getSubExpr();
|
|
|
|
|
|
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 (!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.
|
|
solveRec(viable, FreeTypeVariableBinding::Disallow);
|
|
|
|
// 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(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.
|
|
bool result = diagnoseFailureForExpr(expr);
|
|
assert(result && "didn't diagnose any failure?"); (void)result;
|
|
|
|
return true;
|
|
}
|