mirror of
https://github.com/apple/swift.git
synced 2025-12-21 12:14:44 +01:00
8cf718f9f6
We don't properly open up the existential to make this work, which leads to an IRGen crash. Reject the uses of generics that would cause such a crash rdar://problem/17491663. Swift SVN r21946
1479 lines
49 KiB
C++
1479 lines
49 KiB
C++
//===--- CSDiag.cpp - Constraint Diagnostics ------------------------------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2015 Apple Inc. and the Swift project authors
|
|
// Licensed under Apache License v2.0 with Runtime Library Exception
|
|
//
|
|
// See http://swift.org/LICENSE.txt for license information
|
|
// See http://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file implements diagnostics for the type checker.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
#include "ConstraintSystem.h"
|
|
using namespace swift;
|
|
using namespace constraints;
|
|
|
|
void Failure::dump(SourceManager *sm) const {
|
|
dump(sm, llvm::errs());
|
|
}
|
|
|
|
void Failure::dump(SourceManager *sm, raw_ostream &out) const {
|
|
out << "(";
|
|
if (locator) {
|
|
out << "@";
|
|
locator->dump(sm, out);
|
|
out << ": ";
|
|
}
|
|
|
|
switch (getKind()) {
|
|
case DoesNotConformToProtocol:
|
|
out << getFirstType().getString() << " does not conform to "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case DoesNotHaveMember:
|
|
out << getFirstType().getString() << " does not have a member named '"
|
|
<< getName() << "'";
|
|
break;
|
|
|
|
case DoesNotHaveNonMutatingMember:
|
|
out << " immutable value of type " << getFirstType().getString()
|
|
<< " only has mutating members named '"
|
|
<< getName() << "'";
|
|
break;
|
|
|
|
case FunctionTypesMismatch:
|
|
out << "function type " << getFirstType().getString() << " is not equal to "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case FunctionAutoclosureMismatch:
|
|
out << "autoclosure mismatch " << getFirstType().getString() << " vs. "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case FunctionNoReturnMismatch:
|
|
out << "noreturn attribute mismatch " << getFirstType().getString()
|
|
<< " vs. " << getSecondType().getString();
|
|
break;
|
|
|
|
case IsNotMetatype:
|
|
out << getFirstType().getString() << " is not a metatype";
|
|
break;
|
|
|
|
case IsNotArchetype:
|
|
out << getFirstType().getString() << " is not an archetype";
|
|
break;
|
|
|
|
case IsNotClass:
|
|
out << getFirstType().getString() << " is not a class";
|
|
break;
|
|
|
|
case IsNotBridgedToObjectiveC:
|
|
out << getFirstType().getString() << "is not bridged to Objective-C";
|
|
break;
|
|
|
|
case IsNotDynamicLookup:
|
|
out << getFirstType().getString() << " is not a dynamic lookup value";
|
|
break;
|
|
|
|
case IsNotOptional:
|
|
out << getFirstType().getString() << "is not an optional type";
|
|
break;
|
|
|
|
case TupleNameMismatch:
|
|
case TupleNamePositionMismatch:
|
|
case TupleSizeMismatch:
|
|
case TupleVariadicMismatch:
|
|
case TupleUnused:
|
|
out << "mismatched tuple types " << getFirstType().getString() << " and "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case TypesNotConstructible:
|
|
out << getFirstType().getString() << " is not a constructible argument for "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case TypesNotConvertible:
|
|
out << getFirstType().getString() << " is not convertible to "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case TypesNotSubtypes:
|
|
out << getFirstType().getString() << " is not a subtype of "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case TypesNotEqual:
|
|
out << getFirstType().getString() << " is not equal to "
|
|
<< getSecondType().getString();
|
|
break;
|
|
|
|
case IsForbiddenLValue:
|
|
out << "disallowed l-value binding of " << getFirstType().getString()
|
|
<< " and " << getSecondType().getString();
|
|
break;
|
|
|
|
case OutOfOrderArgument:
|
|
out << "out-of-order argument " << getValue() << " should come before "
|
|
<< getSecondValue();
|
|
break;
|
|
|
|
case MissingArgument:
|
|
out << "missing argument for parameter " << getValue();
|
|
break;
|
|
|
|
case ExtraArgument:
|
|
out << "extra argument " << getValue();
|
|
break;
|
|
|
|
case NoPublicInitializers:
|
|
out << getFirstType().getString()
|
|
<< " does not have any public initializers";
|
|
break;
|
|
|
|
case UnboundGenericParameter:
|
|
out << getFirstType().getString()
|
|
<< " is an unbound generic parameter";
|
|
break;
|
|
|
|
case ExistentialGenericParameter:
|
|
out << getFirstType().getString()
|
|
<< " bound to non-@objc existential type "
|
|
<< getSecondType().getString();
|
|
break;
|
|
}
|
|
|
|
out << ")\n";
|
|
}
|
|
|
|
/// Given a subpath of an old locator, compute its summary flags.
|
|
static unsigned recomputeSummaryFlags(ConstraintLocator *oldLocator,
|
|
ArrayRef<LocatorPathElt> path) {
|
|
if (oldLocator->getSummaryFlags() != 0)
|
|
return ConstraintLocator::getSummaryFlagsForPath(path);
|
|
return 0;
|
|
}
|
|
|
|
ConstraintLocator *
|
|
constraints::simplifyLocator(ConstraintSystem &cs,
|
|
ConstraintLocator *locator,
|
|
SourceRange &range1,
|
|
SourceRange &range2,
|
|
ConstraintLocator **targetLocator) {
|
|
// Clear out the target locator result.
|
|
if (targetLocator)
|
|
*targetLocator = nullptr;
|
|
|
|
// The path to be tacked on to the target locator to identify the specific
|
|
// target.
|
|
Expr *targetAnchor;
|
|
SmallVector<LocatorPathElt, 4> targetPath;
|
|
|
|
auto path = locator->getPath();
|
|
auto anchor = locator->getAnchor();
|
|
simplifyLocator(anchor, path, targetAnchor, targetPath, range1, range2);
|
|
|
|
|
|
// If we have a target anchor, build and simplify the target locator.
|
|
if (targetLocator && targetAnchor) {
|
|
SourceRange targetRange1, targetRange2;
|
|
unsigned targetFlags = recomputeSummaryFlags(locator, targetPath);
|
|
*targetLocator = simplifyLocator(cs,
|
|
cs.getConstraintLocator(targetAnchor,
|
|
targetPath,
|
|
targetFlags),
|
|
targetRange1, targetRange2);
|
|
}
|
|
|
|
// If we didn't simplify anything, just return the input.
|
|
if (anchor == locator->getAnchor() &&
|
|
path.size() == locator->getPath().size()) {
|
|
return locator;
|
|
}
|
|
|
|
// Recompute the summary flags if we had any to begin with. This is
|
|
// necessary because we might remove e.g. tuple elements from the path.
|
|
unsigned summaryFlags = recomputeSummaryFlags(locator, path);
|
|
return cs.getConstraintLocator(anchor, path, summaryFlags);
|
|
}
|
|
|
|
void constraints::simplifyLocator(Expr *&anchor,
|
|
ArrayRef<LocatorPathElt> &path,
|
|
Expr *&targetAnchor,
|
|
SmallVectorImpl<LocatorPathElt> &targetPath,
|
|
SourceRange &range1, SourceRange &range2) {
|
|
range1 = SourceRange();
|
|
range2 = SourceRange();
|
|
targetAnchor = nullptr;
|
|
|
|
while (!path.empty()) {
|
|
switch (path[0].getKind()) {
|
|
case ConstraintLocator::ApplyArgument:
|
|
// Extract application argument.
|
|
if (auto applyExpr = dyn_cast<ApplyExpr>(anchor)) {
|
|
// The target anchor is the function being called.
|
|
targetAnchor = applyExpr->getFn();
|
|
targetPath.push_back(path[0]);
|
|
|
|
anchor = applyExpr->getArg();
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ApplyFunction:
|
|
// Extract application function.
|
|
if (auto applyExpr = dyn_cast<ApplyExpr>(anchor)) {
|
|
// No additional target locator information.
|
|
targetAnchor = nullptr;
|
|
targetPath.clear();
|
|
|
|
anchor = applyExpr->getFn();
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
|
|
// The unresolved member itself is the function.
|
|
if (auto unresolvedMember = dyn_cast<UnresolvedMemberExpr>(anchor)) {
|
|
if (unresolvedMember->getArgument()) {
|
|
// No additional target locator information.
|
|
targetAnchor = nullptr;
|
|
targetPath.clear();
|
|
|
|
anchor = unresolvedMember;
|
|
path = path.slice(1);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
break;
|
|
|
|
case ConstraintLocator::Load:
|
|
case ConstraintLocator::RvalueAdjustment:
|
|
case ConstraintLocator::ScalarToTuple:
|
|
// Loads, rvalue adjustment, and scalar-to-tuple conversions are implicit.
|
|
path = path.slice(1);
|
|
continue;
|
|
|
|
case ConstraintLocator::NamedTupleElement:
|
|
case ConstraintLocator::TupleElement:
|
|
// Extract tuple element.
|
|
if (auto tupleExpr = dyn_cast<TupleExpr>(anchor)) {
|
|
// Append this extraction to the target locator path.
|
|
if (targetAnchor) {
|
|
targetPath.push_back(path[0]);
|
|
}
|
|
|
|
anchor = tupleExpr->getElement(path[0].getValue());
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ApplyArgToParam:
|
|
// Extract tuple element.
|
|
if (auto tupleExpr = dyn_cast<TupleExpr>(anchor)) {
|
|
// Append this extraction to the target locator path.
|
|
if (targetAnchor) {
|
|
targetPath.push_back(path[0]);
|
|
}
|
|
|
|
anchor = tupleExpr->getElement(path[0].getValue());
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
|
|
// Extract subexpression in parentheses.
|
|
if (auto parenExpr = dyn_cast<ParenExpr>(anchor)) {
|
|
assert(path[0].getValue() == 0);
|
|
|
|
// Append this extraction to the target locator path.
|
|
if (targetAnchor) {
|
|
targetPath.push_back(path[0]);
|
|
}
|
|
|
|
anchor = parenExpr->getSubExpr();
|
|
path = path.slice(1);
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::Member:
|
|
case ConstraintLocator::MemberRefBase:
|
|
if (auto dotExpr = dyn_cast<UnresolvedDotExpr>(anchor)) {
|
|
// No additional target locator information.
|
|
targetAnchor = nullptr;
|
|
targetPath.clear();
|
|
|
|
range1 = dotExpr->getNameLoc();
|
|
anchor = dotExpr->getBase();
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::InterpolationArgument:
|
|
if (auto interp = dyn_cast<InterpolatedStringLiteralExpr>(anchor)) {
|
|
// No additional target locator information.
|
|
// FIXME: Dig out the constructor we're trying to call?
|
|
targetAnchor = nullptr;
|
|
targetPath.clear();
|
|
|
|
anchor = interp->getSegments()[path[0].getValue()];
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::AssignSource:
|
|
if (auto assign = dyn_cast<AssignExpr>(anchor)) {
|
|
targetAnchor = assign->getDest();
|
|
targetPath.clear();
|
|
|
|
anchor = assign->getSrc();
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::SubscriptIndex:
|
|
if (auto subscript = dyn_cast<SubscriptExpr>(anchor)) {
|
|
targetAnchor = subscript->getBase();
|
|
targetPath.clear();
|
|
|
|
anchor = subscript->getIndex();
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
break;
|
|
|
|
default:
|
|
// FIXME: Lots of other cases to handle.
|
|
break;
|
|
}
|
|
|
|
// If we get here, we couldn't simplify the path further.
|
|
break;
|
|
}
|
|
}
|
|
|
|
/// Simplify the given locator down to a specific anchor expression,
|
|
/// if possible.
|
|
///
|
|
/// \returns the anchor expression if it fully describes the locator, or
|
|
/// null otherwise.
|
|
static Expr *simplifyLocatorToAnchor(ConstraintSystem &cs,
|
|
ConstraintLocator *locator) {
|
|
if (!locator || !locator->getAnchor())
|
|
return nullptr;
|
|
|
|
SourceRange range1, range2;
|
|
locator = simplifyLocator(cs, locator, range1, range2);
|
|
if (!locator->getAnchor() || !locator->getPath().empty())
|
|
return nullptr;
|
|
|
|
return locator->getAnchor();
|
|
}
|
|
|
|
/// Retrieve the argument pattern for the given declaration.
|
|
///
|
|
static Pattern *getParameterPattern(ValueDecl *decl) {
|
|
if (auto func = dyn_cast<FuncDecl>(decl))
|
|
return func->getBodyParamPatterns()[0];
|
|
if (auto constructor = dyn_cast<ConstructorDecl>(decl))
|
|
return constructor->getBodyParamPatterns()[1];
|
|
if (auto subscript = dyn_cast<SubscriptDecl>(decl))
|
|
return subscript->getIndices();
|
|
|
|
// FIXME: Variables of function type?
|
|
return nullptr;
|
|
}
|
|
|
|
ResolvedLocator constraints::resolveLocatorToDecl(
|
|
ConstraintSystem &cs,
|
|
ConstraintLocator *locator,
|
|
std::function<Optional<SelectedOverload>(ConstraintLocator *)> findOvlChoice,
|
|
std::function<ConcreteDeclRef (ValueDecl *decl,
|
|
Type openedType)> getConcreteDeclRef)
|
|
{
|
|
assert(locator && "Null locator");
|
|
if (!locator->getAnchor())
|
|
return ResolvedLocator();
|
|
|
|
ConcreteDeclRef declRef;
|
|
auto anchor = locator->getAnchor();
|
|
// Unwrap any specializations, constructor calls, implicit conversions, and
|
|
// '.'s.
|
|
// FIXME: This is brittle.
|
|
do {
|
|
if (auto specialize = dyn_cast<UnresolvedSpecializeExpr>(anchor)) {
|
|
anchor = specialize->getSubExpr();
|
|
continue;
|
|
}
|
|
|
|
if (auto implicit = dyn_cast<ImplicitConversionExpr>(anchor)) {
|
|
anchor = implicit->getSubExpr();
|
|
continue;
|
|
}
|
|
|
|
if (auto constructor = dyn_cast<ConstructorRefCallExpr>(anchor)) {
|
|
anchor = constructor->getFn();
|
|
continue;
|
|
}
|
|
|
|
if (auto dotSyntax = dyn_cast<DotSyntaxBaseIgnoredExpr>(anchor)) {
|
|
anchor = dotSyntax->getRHS();
|
|
continue;
|
|
}
|
|
|
|
if (auto dotSyntax = dyn_cast<DotSyntaxCallExpr>(anchor)) {
|
|
anchor = dotSyntax->getFn();
|
|
continue;
|
|
}
|
|
|
|
break;
|
|
} while (true);
|
|
|
|
auto getConcreteDeclRefFromOverload
|
|
= [&](const SelectedOverload &selected) -> ConcreteDeclRef {
|
|
return getConcreteDeclRef(selected.choice.getDecl(),
|
|
selected.openedType);
|
|
};
|
|
|
|
if (auto dre = dyn_cast<DeclRefExpr>(anchor)) {
|
|
// Simple case: direct reference to a declaration.
|
|
declRef = dre->getDeclRef();
|
|
} else if (auto mre = dyn_cast<MemberRefExpr>(anchor)) {
|
|
// Simple case: direct reference to a declaration.
|
|
declRef = mre->getMember();
|
|
} else if (isa<OverloadedDeclRefExpr>(anchor) ||
|
|
isa<OverloadedMemberRefExpr>(anchor) ||
|
|
isa<UnresolvedDeclRefExpr>(anchor)) {
|
|
// Overloaded and unresolved cases: find the resolved overload.
|
|
auto anchorLocator = cs.getConstraintLocator(anchor);
|
|
if (auto selected = findOvlChoice(anchorLocator)) {
|
|
if (selected->choice.isDecl())
|
|
declRef = getConcreteDeclRefFromOverload(*selected);
|
|
}
|
|
} else if (isa<UnresolvedMemberExpr>(anchor)) {
|
|
// Unresolved member: find the resolved overload.
|
|
auto anchorLocator = cs.getConstraintLocator(
|
|
anchor,
|
|
ConstraintLocator::UnresolvedMember);
|
|
if (auto selected = findOvlChoice(anchorLocator)) {
|
|
if (selected->choice.isDecl())
|
|
declRef = getConcreteDeclRefFromOverload(*selected);
|
|
}
|
|
} else if (auto ctorRef = dyn_cast<OtherConstructorDeclRefExpr>(anchor)) {
|
|
declRef = ctorRef->getDeclRef();
|
|
}
|
|
|
|
// If we didn't find the declaration, we're out of luck.
|
|
if (!declRef)
|
|
return ResolvedLocator();
|
|
|
|
// Use the declaration and the path to produce a more specific result.
|
|
// FIXME: This is an egregious hack. We'd be far better off
|
|
// FIXME: Perform deeper path resolution?
|
|
auto path = locator->getPath();
|
|
Pattern *parameterPattern = nullptr;
|
|
bool impliesFullPattern = false;
|
|
while (!path.empty()) {
|
|
switch (path[0].getKind()) {
|
|
case ConstraintLocator::ApplyArgument:
|
|
// If we're calling into something that has parameters, dig into the
|
|
// actual parameter pattern.
|
|
parameterPattern = getParameterPattern(declRef.getDecl());
|
|
if (!parameterPattern)
|
|
break;
|
|
|
|
impliesFullPattern = true;
|
|
path = path.slice(1);
|
|
continue;
|
|
|
|
case ConstraintLocator::TupleElement:
|
|
case ConstraintLocator::NamedTupleElement:
|
|
if (parameterPattern) {
|
|
unsigned index = path[0].getValue();
|
|
if (auto tuple = dyn_cast<TuplePattern>(
|
|
parameterPattern->getSemanticsProvidingPattern())) {
|
|
parameterPattern = tuple->getFields()[index].getPattern();
|
|
impliesFullPattern = false;
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
parameterPattern = nullptr;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ApplyArgToParam:
|
|
if (parameterPattern) {
|
|
unsigned index = path[0].getValue2();
|
|
if (auto tuple = dyn_cast<TuplePattern>(
|
|
parameterPattern->getSemanticsProvidingPattern())) {
|
|
parameterPattern = tuple->getFields()[index].getPattern();
|
|
impliesFullPattern = false;
|
|
path = path.slice(1);
|
|
continue;
|
|
}
|
|
parameterPattern = nullptr;
|
|
}
|
|
break;
|
|
|
|
case ConstraintLocator::ScalarToTuple:
|
|
continue;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
break;
|
|
}
|
|
|
|
// If we have a parameter pattern that refers to a parameter, grab it.
|
|
if (parameterPattern) {
|
|
parameterPattern = parameterPattern->getSemanticsProvidingPattern();
|
|
if (impliesFullPattern) {
|
|
if (auto tuple = dyn_cast<TuplePattern>(parameterPattern)) {
|
|
if (tuple->getFields().size() == 1) {
|
|
parameterPattern = tuple->getFields()[0].getPattern();
|
|
parameterPattern = parameterPattern->getSemanticsProvidingPattern();
|
|
}
|
|
}
|
|
}
|
|
|
|
if (auto named = dyn_cast<NamedPattern>(parameterPattern)) {
|
|
return ResolvedLocator(ResolvedLocator::ForVar, named->getDecl());
|
|
}
|
|
}
|
|
|
|
// Otherwise, do the best we can with the declaration we found.
|
|
if (isa<FuncDecl>(declRef.getDecl()))
|
|
return ResolvedLocator(ResolvedLocator::ForFunction, declRef);
|
|
if (isa<ConstructorDecl>(declRef.getDecl()))
|
|
return ResolvedLocator(ResolvedLocator::ForConstructor, declRef);
|
|
|
|
// FIXME: Deal with the other interesting cases here, e.g.,
|
|
// subscript declarations.
|
|
return ResolvedLocator();
|
|
}
|
|
|
|
/// Emit a note referring to the target of a diagnostic, e.g., the function
|
|
/// or parameter being used.
|
|
static void noteTargetOfDiagnostic(ConstraintSystem &cs,
|
|
const Failure &failure,
|
|
ConstraintLocator *targetLocator) {
|
|
// If there's no anchor, there's nothing we can do.
|
|
if (!targetLocator->getAnchor())
|
|
return;
|
|
|
|
// Try to resolve the locator to a particular declaration.
|
|
auto resolved
|
|
= resolveLocatorToDecl(cs, targetLocator,
|
|
[&](ConstraintLocator *locator) -> Optional<SelectedOverload> {
|
|
for (auto resolved = failure.getResolvedOverloadSets();
|
|
resolved; resolved = resolved->Previous) {
|
|
if (resolved->Locator == locator)
|
|
return SelectedOverload{resolved->Choice,
|
|
resolved->OpenedFullType,
|
|
// FIXME: opened type?
|
|
Type()};
|
|
}
|
|
|
|
return Nothing;
|
|
},
|
|
[&](ValueDecl *decl,
|
|
Type openedType) -> ConcreteDeclRef {
|
|
return decl;
|
|
});
|
|
|
|
// We couldn't resolve the locator to a declaration, so we're done.
|
|
if (!resolved)
|
|
return;
|
|
|
|
switch (resolved.getKind()) {
|
|
case ResolvedLocatorKind::Unresolved:
|
|
// Can't emit any diagnostic here.
|
|
return;
|
|
|
|
case ResolvedLocatorKind::Function: {
|
|
auto name = resolved.getDecl().getDecl()->getName();
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
name.isOperator()? diag::note_call_to_operator
|
|
: diag::note_call_to_func,
|
|
resolved.getDecl().getDecl()->getName());
|
|
return;
|
|
}
|
|
|
|
case ResolvedLocatorKind::Constructor:
|
|
// FIXME: Specialize for implicitly-generated constructors.
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
diag::note_call_to_initializer);
|
|
return;
|
|
|
|
case ResolvedLocatorKind::Parameter:
|
|
cs.getTypeChecker().diagnose(resolved.getDecl().getDecl(),
|
|
diag::note_init_parameter,
|
|
resolved.getDecl().getDecl()->getName());
|
|
return;
|
|
}
|
|
}
|
|
|
|
/// \brief Emit a diagnostic for the given failure.
|
|
///
|
|
/// \param cs The constraint system in which the diagnostic was generated.
|
|
/// \param failure The failure to emit.
|
|
/// \param expr The expression associated with the failure.
|
|
/// \param useExprLoc If the failure lacks a location, use the one associated
|
|
/// with expr.
|
|
///
|
|
/// \returns true if the diagnostic was emitted successfully.
|
|
static bool diagnoseFailure(ConstraintSystem &cs,
|
|
Failure &failure,
|
|
Expr *expr,
|
|
bool useExprLoc) {
|
|
ConstraintLocator *cloc;
|
|
if (!failure.getLocator() || !failure.getLocator()->getAnchor()) {
|
|
if (useExprLoc)
|
|
cloc = cs.getConstraintLocator(expr);
|
|
else
|
|
return false;
|
|
} else {
|
|
cloc = failure.getLocator();
|
|
}
|
|
|
|
SourceRange range1, range2;
|
|
|
|
ConstraintLocator *targetLocator;
|
|
auto locator = simplifyLocator(cs, cloc, range1, range2,
|
|
&targetLocator);
|
|
auto &tc = cs.getTypeChecker();
|
|
|
|
auto anchor = locator->getAnchor();
|
|
auto loc = anchor->getLoc();
|
|
switch (failure.getKind()) {
|
|
case Failure::TupleSizeMismatch: {
|
|
auto tuple1 = failure.getFirstType()->castTo<TupleType>();
|
|
auto tuple2 = failure.getSecondType()->castTo<TupleType>();
|
|
tc.diagnose(loc, diag::invalid_tuple_size, tuple1, tuple2,
|
|
tuple1->getFields().size(),
|
|
tuple2->getFields().size())
|
|
.highlight(range1).highlight(range2);
|
|
break;
|
|
}
|
|
|
|
case Failure::TupleUnused:
|
|
tc.diagnose(loc, diag::invalid_tuple_element_unused,
|
|
failure.getFirstType(),
|
|
failure.getSecondType())
|
|
.highlight(range1).highlight(range2);
|
|
break;
|
|
|
|
case Failure::TypesNotEqual:
|
|
case Failure::TypesNotSubtypes:
|
|
case Failure::TypesNotConvertible:
|
|
case Failure::TypesNotConstructible:
|
|
case Failure::FunctionTypesMismatch:
|
|
tc.diagnose(loc, diag::invalid_relation,
|
|
failure.getKind() - Failure::TypesNotEqual,
|
|
failure.getFirstType(),
|
|
failure.getSecondType())
|
|
.highlight(range1).highlight(range2);
|
|
if (targetLocator && !useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
|
|
case Failure::DoesNotHaveMember:
|
|
case Failure::DoesNotHaveNonMutatingMember:
|
|
if (auto moduleTy = failure.getFirstType()->getAs<ModuleType>()) {
|
|
tc.diagnose(loc, diag::no_member_of_module,
|
|
moduleTy->getModule()->Name,
|
|
failure.getName())
|
|
.highlight(range1).highlight(range2);
|
|
} else {
|
|
bool IsNoMember = failure.getKind() == Failure::DoesNotHaveMember;
|
|
|
|
tc.diagnose(loc, IsNoMember ? diag::does_not_have_member :
|
|
diag::does_not_have_non_mutating_member,
|
|
failure.getFirstType(),
|
|
failure.getName())
|
|
.highlight(range1).highlight(range2);
|
|
}
|
|
break;
|
|
|
|
case Failure::DoesNotConformToProtocol:
|
|
// FIXME: Probably want to do this within the actual solver, because at
|
|
// this point it's too late to actually recover fully.
|
|
tc.conformsToProtocol(failure.getFirstType(),
|
|
failure.getSecondType()->castTo<ProtocolType>()
|
|
->getDecl(),
|
|
cs.DC,
|
|
nullptr,
|
|
loc);
|
|
if (targetLocator)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
|
|
case Failure::IsNotBridgedToObjectiveC:
|
|
tc.diagnose(loc, diag::type_not_bridged, failure.getFirstType());
|
|
if (targetLocator)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
|
|
case Failure::IsForbiddenLValue:
|
|
if (auto iotTy = failure.getSecondType()->getAs<InOutType>()) {
|
|
tc.diagnose(loc, diag::reference_non_inout, iotTy->getObjectType())
|
|
.highlight(range1).highlight(range2);
|
|
return true;
|
|
}
|
|
// FIXME: diagnose other cases
|
|
return false;
|
|
|
|
case Failure::OutOfOrderArgument:
|
|
if (auto tuple = dyn_cast_or_null<TupleExpr>(anchor)) {
|
|
unsigned firstIdx = failure.getValue();
|
|
Identifier first = tuple->getElementName(firstIdx);
|
|
unsigned secondIdx = failure.getSecondValue();
|
|
Identifier second = tuple->getElementName(secondIdx);
|
|
if (!first.empty() && !second.empty()) {
|
|
tc.diagnose(tuple->getElementNameLoc(firstIdx),
|
|
diag::argument_out_of_order, first, second)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange())
|
|
.highlight(SourceRange(tuple->getElementNameLoc(secondIdx),
|
|
tuple->getElement(secondIdx)->getEndLoc()));
|
|
return true;
|
|
}
|
|
}
|
|
// FIXME: Can this even happen?
|
|
return false;
|
|
|
|
case Failure::MissingArgument: {
|
|
Identifier name;
|
|
unsigned idx = failure.getValue();
|
|
if (auto tupleTy = failure.getFirstType()->getAs<TupleType>()) {
|
|
name = tupleTy->getFields()[idx].getName();
|
|
} else {
|
|
// Scalar.
|
|
assert(idx == 0);
|
|
}
|
|
|
|
if (name.empty())
|
|
tc.diagnose(loc, diag::missing_argument_positional, idx+1);
|
|
else
|
|
tc.diagnose(loc, diag::missing_argument_named, name);
|
|
return true;
|
|
}
|
|
|
|
case Failure::ExtraArgument: {
|
|
if (auto tuple = dyn_cast_or_null<TupleExpr>(anchor)) {
|
|
unsigned firstIdx = failure.getValue();
|
|
auto name = tuple->getElementName(firstIdx);
|
|
if (name.empty())
|
|
tc.diagnose(loc, diag::extra_argument_positional)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange());
|
|
else
|
|
tc.diagnose(loc, diag::extra_argument_named, name)
|
|
.highlight(tuple->getElement(firstIdx)->getSourceRange());
|
|
return true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
case Failure::IsNotOptional: {
|
|
if (auto force = dyn_cast_or_null<ForceValueExpr>(anchor)) {
|
|
// If there was an 'as' cast in the subexpression, note it.
|
|
if (auto cast = findForcedDowncast(tc.Context, force->getSubExpr())) {
|
|
tc.diagnose(force->getLoc(), diag::forcing_explicit_downcast,
|
|
failure.getFirstType())
|
|
.highlight(cast->getLoc())
|
|
.fixItRemove(force->getLoc());
|
|
return true;
|
|
}
|
|
|
|
tc.diagnose(loc, diag::forcing_injected_optional,
|
|
failure.getFirstType())
|
|
.highlight(force->getSourceRange())
|
|
.fixItRemove(force->getExclaimLoc());
|
|
|
|
return true;
|
|
}
|
|
|
|
if (auto bind = dyn_cast_or_null<BindOptionalExpr>(anchor)) {
|
|
tc.diagnose(loc, diag::binding_injected_optional,
|
|
failure.getFirstType())
|
|
.highlight(bind->getSourceRange())
|
|
.fixItRemove(bind->getQuestionLoc());
|
|
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
case Failure::NoPublicInitializers: {
|
|
tc.diagnose(loc, diag::no_accessible_initializers, failure.getFirstType())
|
|
.highlight(range1);
|
|
if (targetLocator && !useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, targetLocator);
|
|
break;
|
|
}
|
|
|
|
case Failure::UnboundGenericParameter: {
|
|
tc.diagnose(loc, diag::unbound_generic_parameter, failure.getFirstType())
|
|
.highlight(range1);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::ExistentialGenericParameter: {
|
|
tc.diagnose(loc, diag::generic_parameter_binds_to_non_objc_existential,
|
|
failure.getFirstType(), failure.getSecondType())
|
|
.highlight(range1);
|
|
if (!useExprLoc)
|
|
noteTargetOfDiagnostic(cs, failure, locator);
|
|
break;
|
|
}
|
|
|
|
case Failure::FunctionAutoclosureMismatch:
|
|
case Failure::FunctionNoReturnMismatch:
|
|
case Failure::IsNotArchetype:
|
|
case Failure::IsNotClass:
|
|
case Failure::IsNotDynamicLookup:
|
|
case Failure::IsNotMetatype:
|
|
case Failure::TupleNameMismatch:
|
|
case Failure::TupleNamePositionMismatch:
|
|
case Failure::TupleVariadicMismatch:
|
|
// FIXME: Handle all failure kinds
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/// \brief Determine the number of distinct overload choices in the
|
|
/// provided set.
|
|
static unsigned countDistinctOverloads(ArrayRef<OverloadChoice> choices) {
|
|
llvm::SmallPtrSet<void *, 4> uniqueChoices;
|
|
unsigned result = 0;
|
|
for (auto choice : choices) {
|
|
if (uniqueChoices.insert(choice.getOpaqueChoiceSimple()))
|
|
++result;
|
|
}
|
|
return result;
|
|
}
|
|
|
|
/// \brief Determine the name of the overload in a set of overload choices.
|
|
static Identifier getOverloadChoiceName(ArrayRef<OverloadChoice> choices) {
|
|
for (auto choice : choices) {
|
|
if (choice.isDecl())
|
|
return choice.getDecl()->getName();
|
|
}
|
|
|
|
return Identifier();
|
|
}
|
|
|
|
bool diagnoseAmbiguity(ConstraintSystem &cs, ArrayRef<Solution> solutions) {
|
|
// Produce a diff of the solutions.
|
|
SolutionDiff diff(solutions);
|
|
|
|
// Find the locators which have the largest numbers of distinct overloads.
|
|
SmallVector<unsigned, 2> mostDistinctOverloads;
|
|
unsigned maxDistinctOverloads = 0;
|
|
for (unsigned i = 0, n = diff.overloads.size(); i != n; ++i) {
|
|
auto &overload = diff.overloads[i];
|
|
|
|
// If we can't resolve the locator to an anchor expression with no path,
|
|
// we can't diagnose this well.
|
|
if (!simplifyLocatorToAnchor(cs, overload.locator))
|
|
continue;
|
|
|
|
// If we don't have a name to hang on to, it'll be hard to diagnose this
|
|
// overload.
|
|
if (getOverloadChoiceName(overload.choices).empty())
|
|
continue;
|
|
|
|
unsigned distinctOverloads = countDistinctOverloads(overload.choices);
|
|
|
|
// We need at least two overloads to make this interesting.
|
|
if (distinctOverloads < 2)
|
|
continue;
|
|
|
|
// If we have more distinct overload choices for this locator than for
|
|
// prior locators, just keep this locator.
|
|
if (distinctOverloads > maxDistinctOverloads) {
|
|
maxDistinctOverloads = distinctOverloads;
|
|
mostDistinctOverloads.clear();
|
|
mostDistinctOverloads.push_back(i);
|
|
continue;
|
|
}
|
|
|
|
// If we have as many distinct overload choices for this locator as
|
|
// the best so far, add this locator to the set.
|
|
if (distinctOverloads == maxDistinctOverloads) {
|
|
mostDistinctOverloads.push_back(i);
|
|
continue;
|
|
}
|
|
|
|
// We have better results. Ignore this one.
|
|
}
|
|
|
|
// FIXME: Should be able to pick the best locator, e.g., based on some
|
|
// depth-first numbering of expressions.
|
|
if (mostDistinctOverloads.size() == 1) {
|
|
auto &overload = diff.overloads[mostDistinctOverloads[0]];
|
|
auto name = getOverloadChoiceName(overload.choices);
|
|
auto anchor = simplifyLocatorToAnchor(cs, overload.locator);
|
|
|
|
// Emit the ambiguity diagnostic.
|
|
auto &tc = cs.getTypeChecker();
|
|
tc.diagnose(anchor->getLoc(),
|
|
name.isOperator() ? diag::ambiguous_operator_ref
|
|
: diag::ambiguous_decl_ref,
|
|
name);
|
|
|
|
// Emit candidates. Use a SmallPtrSet to make sure only emit a particular
|
|
// candidate once. FIXME: Why is one candidate getting into the overload
|
|
// set multiple times?
|
|
SmallPtrSet<Decl*, 8> EmittedDecls;
|
|
for (auto choice : overload.choices) {
|
|
switch (choice.getKind()) {
|
|
case OverloadChoiceKind::Decl:
|
|
case OverloadChoiceKind::DeclViaDynamic:
|
|
case OverloadChoiceKind::TypeDecl:
|
|
case OverloadChoiceKind::DeclViaBridge:
|
|
case OverloadChoiceKind::DeclViaUnwrappedOptional:
|
|
// FIXME: show deduced types, etc, etc.
|
|
if (EmittedDecls.insert(choice.getDecl()))
|
|
tc.diagnose(choice.getDecl(), diag::found_candidate);
|
|
break;
|
|
|
|
case OverloadChoiceKind::BaseType:
|
|
case OverloadChoiceKind::TupleIndex:
|
|
// FIXME: Actually diagnose something here.
|
|
break;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// FIXME: If we inferred different types for literals (for example),
|
|
// could diagnose ambiguity that way as well.
|
|
|
|
return false;
|
|
}
|
|
|
|
Constraint *getConstraintChoice(Constraint *constraint,
|
|
ConstraintKind kind,
|
|
bool takeAny = false) {
|
|
if ((constraint->getKind() != ConstraintKind::Disjunction) &&
|
|
(constraint->getKind() != ConstraintKind::Conjunction)) {
|
|
return nullptr;
|
|
}
|
|
|
|
auto nestedConstraints = constraint->getNestedConstraints();
|
|
|
|
for (auto nestedConstraint : nestedConstraints) {
|
|
if (takeAny ||
|
|
(nestedConstraint->getKind() == kind)) {
|
|
|
|
// If this is a last-chance search, and we have a conjunction or
|
|
// disjunction, look within.
|
|
if (takeAny &&
|
|
((nestedConstraint->getKind() == ConstraintKind::Disjunction) ||
|
|
(nestedConstraint->getKind() == ConstraintKind::Conjunction))) {
|
|
return getConstraintChoice(nestedConstraint,
|
|
kind,
|
|
takeAny);
|
|
}
|
|
|
|
return nestedConstraint;
|
|
}
|
|
}
|
|
|
|
return nullptr;
|
|
}
|
|
|
|
Constraint *getComponentConstraint(Constraint *constraint) {
|
|
if (constraint->getKind() != ConstraintKind::Disjunction) {
|
|
return constraint;
|
|
}
|
|
|
|
return constraint->getNestedConstraints().front();
|
|
}
|
|
|
|
/// For a given expression type, extract the appropriate type for a constraint-
|
|
/// based diagnostic.
|
|
static Type getDiagnosticTypeFromExpr(Expr *expr) {
|
|
|
|
// For an unresolved checked cast expression, use the type of the
|
|
// sub-expression.
|
|
if (auto ucc = dyn_cast<UnresolvedCheckedCastExpr>(expr)) {
|
|
auto subExpr = ucc->getSubExpr();
|
|
|
|
return subExpr->getType();
|
|
}
|
|
|
|
// For an application expression, use the argument type.
|
|
if (auto applyExpr = dyn_cast<ApplyExpr>(expr)) {
|
|
return applyExpr->getArg()->getType();
|
|
}
|
|
|
|
// For a subscript expression, use the index type.
|
|
if (auto subscriptExpr = dyn_cast<SubscriptExpr>(expr)) {
|
|
return subscriptExpr->getIndex()->getType();
|
|
}
|
|
|
|
return expr->getType();
|
|
}
|
|
|
|
/// If a type variable was created for an opened literal expression, substitute
|
|
/// in the default literal for the type variable's literal conformance.
|
|
static Type substituteLiteralForTypeVariable(ConstraintSystem *CS,
|
|
TypeVariableType *tv) {
|
|
if (auto proto = tv->getImpl().literalConformanceProto) {
|
|
|
|
auto kind = proto->getKnownProtocolKind();
|
|
|
|
if (kind.hasValue()) {
|
|
auto altLits = CS->getAlternativeLiteralTypes(kind.getValue());
|
|
if (!altLits.empty()) {
|
|
if (auto altType = altLits[0]) {
|
|
return altType;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
return tv;
|
|
}
|
|
|
|
static std::pair<Type, Type> getBoundTypesFromConstraint(ConstraintSystem *CS,
|
|
Expr *expr,
|
|
Constraint *constraint) {
|
|
auto type1 = getDiagnosticTypeFromExpr(expr);
|
|
auto type2 = constraint->getSecondType();
|
|
|
|
if (type1->isEqual(type2))
|
|
if (auto firstType = constraint->getFirstType())
|
|
type1 = firstType;
|
|
|
|
if (auto typeVariableType =
|
|
dyn_cast<TypeVariableType>(type2.getPointer())) {
|
|
SmallVector<Type, 4> bindings;
|
|
CS->getComputedBindings(typeVariableType, bindings);
|
|
auto binding = bindings.size() ? bindings.front() : Type();
|
|
|
|
if (!binding.isNull()) {
|
|
if (binding.getPointer() != type1.getPointer())
|
|
type2 = binding;
|
|
} else {
|
|
auto impl = typeVariableType->getImpl();
|
|
if (auto archetypeType = impl.getArchetype()) {
|
|
type2 = archetypeType;
|
|
} else {
|
|
auto implAnchor = impl.getLocator()->getAnchor();
|
|
auto anchorType = implAnchor->getType();
|
|
|
|
// Don't re-substitute an opened type variable for itself.
|
|
if (anchorType.getPointer() != type1.getPointer())
|
|
type2 = anchorType;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (auto typeVariableType =
|
|
dyn_cast<TypeVariableType>(type1.getPointer())) {
|
|
SmallVector<Type, 4> bindings;
|
|
|
|
CS->getComputedBindings(typeVariableType, bindings);
|
|
|
|
for (auto binding : bindings) {
|
|
if (type2.getPointer() != binding.getPointer()) {
|
|
type1 = binding;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// If we still have a literal type variable, substitute in the default type.
|
|
if (auto tv1 = type1->getAs<TypeVariableType>()) {
|
|
type1 = substituteLiteralForTypeVariable(CS, tv1);
|
|
}
|
|
if (auto tv2 = type2->getAs<TypeVariableType>()) {
|
|
type2 = substituteLiteralForTypeVariable(CS, tv2);
|
|
}
|
|
|
|
return std::pair<Type, Type>(type1->getLValueOrInOutObjectType(),
|
|
type2->getLValueOrInOutObjectType());
|
|
}
|
|
|
|
bool ConstraintSystem::diagnoseFailureFromConstraints(Expr *expr) {
|
|
|
|
// If we've been asked for more detailed type-check diagnostics, mine the
|
|
// system's active and inactive constraints for information on why we could
|
|
// not find a solution.
|
|
Constraint *conversionConstraint = nullptr;
|
|
Constraint *overloadConstraint = nullptr;
|
|
Constraint *fallbackConstraint = nullptr;
|
|
Constraint *activeConformanceConstraint = nullptr;
|
|
Constraint *valueMemberConstraint = nullptr;
|
|
Constraint *argumentConstraint = nullptr;
|
|
Constraint *disjunctionConversionConstraint = nullptr;
|
|
Constraint *conformanceConstraint = nullptr;
|
|
|
|
if(!ActiveConstraints.empty()) {
|
|
// If any active conformance constraints are in the system, we know that
|
|
// any inactive constraints are in its service. Capture the constraint and
|
|
// present this information to the user.
|
|
auto *constraint = &ActiveConstraints.front();
|
|
|
|
activeConformanceConstraint = getComponentConstraint(constraint);
|
|
}
|
|
|
|
for (auto & constraintRef : InactiveConstraints) {
|
|
auto constraint = &constraintRef;
|
|
|
|
// Capture the first non-disjunction constraint we find. We'll use this
|
|
// if we can't find a clearer reason for the failure.
|
|
if ((!fallbackConstraint || constraint->isFavored()) &&
|
|
(constraint->getKind() != ConstraintKind::Disjunction) &&
|
|
(constraint->getKind() != ConstraintKind::Conjunction)) {
|
|
fallbackConstraint = constraint;
|
|
}
|
|
|
|
// Store off conversion constraints, favoring existing conversion
|
|
// constraints.
|
|
if ((!(activeConformanceConstraint ||
|
|
conformanceConstraint) || constraint->isFavored()) &&
|
|
constraint->getKind() == ConstraintKind::ConformsTo) {
|
|
conformanceConstraint = constraint;
|
|
}
|
|
|
|
// Failed binding constraints point to a missing member.
|
|
if ((!valueMemberConstraint || constraint->isFavored()) &&
|
|
(constraint->getKind() == ConstraintKind::ValueMember
|
|
|| constraint->getKind() == ConstraintKind::UnresolvedValueMember)) {
|
|
valueMemberConstraint = constraint;
|
|
}
|
|
|
|
// A missed argument conversion can result in better error messages when
|
|
// a user passes the wrong arguments to a function application.
|
|
if ((!argumentConstraint || constraint->isFavored())) {
|
|
argumentConstraint = getConstraintChoice(constraint,
|
|
ConstraintKind::
|
|
ArgumentTupleConversion);
|
|
}
|
|
|
|
// Overload resolution failures are often nicely descriptive, so store
|
|
// off the first one we find.
|
|
if ((!overloadConstraint || constraint->isFavored())) {
|
|
overloadConstraint = getConstraintChoice(constraint,
|
|
ConstraintKind::BindOverload);
|
|
}
|
|
|
|
// Conversion constraints are also nicely descriptive, so we'll grab the
|
|
// first one of those as well.
|
|
if ((!conversionConstraint || constraint->isFavored()) &&
|
|
(constraint->getKind() == ConstraintKind::Conversion ||
|
|
constraint->getKind() == ConstraintKind::ArgumentTupleConversion)) {
|
|
conversionConstraint = constraint;
|
|
}
|
|
|
|
// 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 &&
|
|
this->failedConstraint &&
|
|
this->failedConstraint->getKind() != ConstraintKind::Disjunction) {
|
|
conversionConstraint = this->failedConstraint;
|
|
}
|
|
|
|
if (valueMemberConstraint) {
|
|
auto memberName = valueMemberConstraint->getMember().getBaseName();
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::could_not_find_member,
|
|
memberName)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
if (activeConformanceConstraint) {
|
|
std::pair<Type, Type> types = getBoundTypesFromConstraint(
|
|
this,
|
|
expr,
|
|
activeConformanceConstraint);
|
|
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::does_not_conform_to_constraint,
|
|
types.first,
|
|
types.second)
|
|
.highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
// In the absense of a better conversion constraint failure, point out the
|
|
// inability to find an appropriate overload.
|
|
if (overloadConstraint) {
|
|
auto overloadChoice = overloadConstraint->getOverloadChoice();
|
|
auto overloadName = overloadChoice.getDecl()->getName();
|
|
Type argType = getDiagnosticTypeFromExpr(expr);
|
|
|
|
if (!argType.isNull() &&
|
|
!argType->getAs<TypeVariableType>() &&
|
|
dyn_cast<ApplyExpr>(expr)) {
|
|
if (argType->getAs<TupleType>()) {
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload_with_type_list,
|
|
overloadName.str(), argType)
|
|
.highlight(expr->getSourceRange());
|
|
} else {
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload_with_type,
|
|
overloadName.str(), argType)
|
|
.highlight(expr->getSourceRange());
|
|
}
|
|
} else {
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::cannot_find_appropriate_overload,
|
|
overloadName.str())
|
|
.highlight(expr->getSourceRange());
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// Otherwise, if we have a conversion constraint, use that as the basis for
|
|
// the diagnostic.
|
|
if (conversionConstraint || argumentConstraint) {
|
|
auto constraint = argumentConstraint ?
|
|
argumentConstraint : conversionConstraint;
|
|
|
|
if (conformanceConstraint) {
|
|
if (conformanceConstraint->getTypeVariables().size() <
|
|
constraint->getTypeVariables().size()) {
|
|
constraint = conformanceConstraint;
|
|
}
|
|
}
|
|
|
|
auto locator = constraint->getLocator();
|
|
auto anchor = locator ? locator->getAnchor() : expr;
|
|
std::pair<Type, Type> types = getBoundTypesFromConstraint(this,
|
|
expr,
|
|
constraint);
|
|
|
|
if (argumentConstraint) {
|
|
TC.diagnose(expr->getLoc(),
|
|
diag::could_not_convert_argument,
|
|
types.first).
|
|
highlight(anchor->getSourceRange());
|
|
} else {
|
|
|
|
// If it's a type variable failing a conformance, avoid printing the type
|
|
// variable and just print the conformance.
|
|
if ((constraint->getKind() == ConstraintKind::ConformsTo) &&
|
|
types.first->getAs<TypeVariableType>()) {
|
|
TC.diagnose(anchor->getLoc(),
|
|
diag::single_expression_conformance_failure,
|
|
types.first)
|
|
.highlight(anchor->getSourceRange());
|
|
} else {
|
|
TC.diagnose(anchor->getLoc(),
|
|
diag::cannot_find_conversion,
|
|
types.first, types.second)
|
|
.highlight(anchor->getSourceRange());
|
|
}
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
/// Given an expression and a failure, determine if we should emit a diagnostic
|
|
/// based on the recorded failure, or instead emit a diagnostic based on the
|
|
/// system's failed constraints.
|
|
static bool shouldDiagnoseFromConstraints(Expr * expr, Failure &failure) {
|
|
|
|
// For applications and unresolved 'dot' expressions, we can produce a better
|
|
// diagnostic than 'cannot convert type' by mining the inactive constraints.
|
|
if (dyn_cast<ApplyExpr>(expr) ||
|
|
dyn_cast<UnresolvedDotExpr>(expr))
|
|
return failure.getKind() == Failure::FailureKind::TypesNotConvertible;
|
|
|
|
return false;
|
|
}
|
|
|
|
bool ConstraintSystem::salvage(SmallVectorImpl<Solution> &viable,
|
|
Expr *expr,
|
|
bool onlyFailures) {
|
|
|
|
// If there were any unavoidable failures, emit the first one we can.
|
|
if (!unavoidableFailures.empty()) {
|
|
for (auto failure : unavoidableFailures) {
|
|
|
|
// In the 'onlyFailures' case, we'll want to synthesize a locator if one
|
|
// does not exist. That allows us to emit decent diagnostics for
|
|
// constraint application failures where the constraints themselves lack
|
|
// a valid location.
|
|
if (diagnoseFailure(*this, *failure, expr, onlyFailures))
|
|
return true;
|
|
}
|
|
|
|
if (onlyFailures)
|
|
return true;
|
|
|
|
// If we can't make sense of the existing constraints (or none exist), go
|
|
// ahead and try the unavoidable failures again, but with locator
|
|
// substitutions in place.
|
|
if (!this->diagnoseFailureFromConstraints(expr) &&
|
|
!unavoidableFailures.empty()) {
|
|
for (auto failure : unavoidableFailures) {
|
|
if (diagnoseFailure(*this, *failure, expr, true))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// There were no unavoidable failures, so attempt to solve again, capturing
|
|
// any failures that come from our attempts to select overloads or bind
|
|
// type variables.
|
|
{
|
|
viable.clear();
|
|
|
|
// Set up solver state.
|
|
SolverState state(*this);
|
|
state.recordFailures = true;
|
|
this->solverState = &state;
|
|
|
|
// Solve the system.
|
|
solve(viable);
|
|
|
|
// Check whether we have a best solution; this can happen if we found
|
|
// a series of fixes that worked.
|
|
if (auto best = findBestSolution(viable, /*minimize=*/true)) {
|
|
if (*best != 0)
|
|
viable[0] = std::move(viable[*best]);
|
|
viable.erase(viable.begin() + 1, viable.end());
|
|
return false;
|
|
}
|
|
|
|
// FIXME: If we were able to actually fix things along the way,
|
|
// we may have to hunt for the best solution. For now, we don't care.
|
|
|
|
// If there are multiple solutions, try to diagnose an ambiguity.
|
|
if (viable.size() > 1) {
|
|
if (getASTContext().LangOpts.DebugConstraintSolver) {
|
|
auto &log = getASTContext().TypeCheckerDebug->getStream();
|
|
log << "---Ambiguity error: "
|
|
<< viable.size() << " solutions found---\n";
|
|
int i = 0;
|
|
for (auto &solution : viable) {
|
|
log << "---Ambiguous solution #" << i++ << "---\n";
|
|
solution.dump(&TC.Context.SourceMgr, log);
|
|
log << "\n";
|
|
}
|
|
}
|
|
|
|
if (diagnoseAmbiguity(*this, viable)) {
|
|
return true;
|
|
}
|
|
}
|
|
|
|
// Remove the solver state.
|
|
this->solverState = nullptr;
|
|
|
|
// Fall through to produce diagnostics.
|
|
}
|
|
|
|
if (failures.size()) {
|
|
auto &failure = unavoidableFailures.empty()? *failures.begin()
|
|
: **unavoidableFailures.begin();
|
|
|
|
if (!unavoidableFailures.empty() ||
|
|
!shouldDiagnoseFromConstraints(expr, failure)) {
|
|
if (diagnoseFailure(*this, failure, expr, failures.size() > 1))
|
|
return true;
|
|
}
|
|
}
|
|
|
|
if (getExpressionTooComplex()) {
|
|
TC.diagnose(expr->getLoc(), diag::expression_too_complex).
|
|
highlight(expr->getSourceRange());
|
|
|
|
return true;
|
|
}
|
|
|
|
// If all else fails, attempt to diagnose the failure by looking through the
|
|
// system's constraints.
|
|
this->diagnoseFailureFromConstraints(expr);
|
|
|
|
return true;
|
|
}
|