mirror of
https://github.com/apple/swift.git
synced 2025-12-14 20:36:38 +01:00
098f8e0ebf
In member ref expressions, if the base is optional, and the expected expression result is either optional or unknown, suggest a fixit that makes it into an optional chain expr rather than force unwrapping. Since in many cases the actual fixit is emitted during diagnosis, and thus, while type checking sub exprs with no contextual type specified (so nothing to check for preferring optionality), we also need an additional flag to pass down from FailureDiagnosis for whether we prefer to fix as force unwrapping or optional chaining. I attempted to do this same job via providing a convert type but setting the ConvertTypeIsOnlyAHint flag on the type checker, but unfortunately there are a lot of other moving parts that look at that type, even if it is only supposed to be a hint, so an additional flag to the CS ended up being cleaner.
650 lines
23 KiB
C++
650 lines
23 KiB
C++
//===--- Constraint.cpp - Constraint in the Type Checker ------------------===//
|
|
//
|
|
// This source file is part of the Swift.org open source project
|
|
//
|
|
// Copyright (c) 2014 - 2016 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 the \c Constraint class and its related types,
|
|
// which is used by the constraint-based type checker to describe a
|
|
// constraint that must be solved.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
#include "Constraint.h"
|
|
#include "ConstraintSystem.h"
|
|
#include "swift/AST/Types.h"
|
|
#include "swift/Basic/Fallthrough.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Support/SaveAndRestore.h"
|
|
#include <algorithm>
|
|
|
|
using namespace swift;
|
|
using namespace constraints;
|
|
|
|
Constraint::Constraint(ConstraintKind kind, ArrayRef<Constraint *> constraints,
|
|
ConstraintLocator *locator,
|
|
ArrayRef<TypeVariableType *> typeVars)
|
|
: Kind(kind), HasRestriction(false), HasFix(false), IsActive(false),
|
|
RememberChoice(false), IsFavored(false), NumTypeVariables(typeVars.size()),
|
|
Nested(constraints), Locator(locator)
|
|
{
|
|
assert(kind == ConstraintKind::Disjunction);
|
|
std::uninitialized_copy(typeVars.begin(), typeVars.end(),
|
|
getTypeVariablesBuffer().begin());
|
|
}
|
|
|
|
Constraint::Constraint(ConstraintKind Kind, Type First, Type Second,
|
|
DeclName Member, ConstraintLocator *locator,
|
|
ArrayRef<TypeVariableType *> typeVars)
|
|
: Kind(Kind), HasRestriction(false), HasFix(false), IsActive(false),
|
|
RememberChoice(false), IsFavored(false), NumTypeVariables(typeVars.size()),
|
|
Types { First, Second, Member }, Locator(locator)
|
|
{
|
|
switch (Kind) {
|
|
case ConstraintKind::Bind:
|
|
case ConstraintKind::Equal:
|
|
case ConstraintKind::BindParam:
|
|
case ConstraintKind::Subtype:
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
case ConstraintKind::ArgumentConversion:
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentConversion:
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::CheckedCast:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
case ConstraintKind::DynamicTypeOf:
|
|
case ConstraintKind::OptionalObject:
|
|
assert(!First.isNull());
|
|
assert(!Second.isNull());
|
|
assert(!Member && "Relational constraint cannot have a member");
|
|
break;
|
|
case ConstraintKind::ApplicableFunction:
|
|
assert(First->is<FunctionType>()
|
|
&& "The left-hand side type should be a function type");
|
|
assert(!Member && "Relational constraint cannot have a member");
|
|
break;
|
|
|
|
case ConstraintKind::TypeMember:
|
|
case ConstraintKind::ValueMember:
|
|
case ConstraintKind::UnresolvedValueMember:
|
|
assert(Member && "Member constraint has no member");
|
|
break;
|
|
|
|
case ConstraintKind::Archetype:
|
|
case ConstraintKind::Class:
|
|
case ConstraintKind::BridgedToObjectiveC:
|
|
assert(!Member && "Type property cannot have a member");
|
|
assert(Second.isNull() && "Type property with second type");
|
|
break;
|
|
|
|
case ConstraintKind::Defaultable:
|
|
assert(!First.isNull());
|
|
assert(!Second.isNull());
|
|
assert(!Member && "Defaultable constraint cannot have a member");
|
|
break;
|
|
|
|
case ConstraintKind::BindOverload:
|
|
llvm_unreachable("Wrong constructor for overload binding constraint");
|
|
|
|
case ConstraintKind::Disjunction:
|
|
llvm_unreachable("Disjunction constraints should use create()");
|
|
}
|
|
|
|
std::copy(typeVars.begin(), typeVars.end(), getTypeVariablesBuffer().begin());
|
|
}
|
|
|
|
Constraint::Constraint(Type type, OverloadChoice choice,
|
|
ConstraintLocator *locator,
|
|
ArrayRef<TypeVariableType *> typeVars)
|
|
: Kind(ConstraintKind::BindOverload),
|
|
HasRestriction(false), HasFix(false), IsActive(false),
|
|
RememberChoice(false), IsFavored(false), NumTypeVariables(typeVars.size()),
|
|
Overload{type, choice}, Locator(locator)
|
|
{
|
|
std::copy(typeVars.begin(), typeVars.end(), getTypeVariablesBuffer().begin());
|
|
}
|
|
|
|
Constraint::Constraint(ConstraintKind kind,
|
|
ConversionRestrictionKind restriction,
|
|
Type first, Type second, ConstraintLocator *locator,
|
|
ArrayRef<TypeVariableType *> typeVars)
|
|
: Kind(kind), Restriction(restriction),
|
|
HasRestriction(true), HasFix(false), IsActive(false),
|
|
RememberChoice(false), IsFavored(false), NumTypeVariables(typeVars.size()),
|
|
Types{ first, second, Identifier() }, Locator(locator)
|
|
{
|
|
assert(!first.isNull());
|
|
assert(!second.isNull());
|
|
std::copy(typeVars.begin(), typeVars.end(), getTypeVariablesBuffer().begin());
|
|
}
|
|
|
|
Constraint::Constraint(ConstraintKind kind, Fix fix,
|
|
Type first, Type second, ConstraintLocator *locator,
|
|
ArrayRef<TypeVariableType *> typeVars)
|
|
: Kind(kind), TheFix(fix.getKind()), FixData(fix.getData()),
|
|
HasRestriction(false), HasFix(true),
|
|
IsActive(false), RememberChoice(false), IsFavored(false),
|
|
NumTypeVariables(typeVars.size()),
|
|
Types{ first, second, Identifier() }, Locator(locator)
|
|
{
|
|
assert(!first.isNull());
|
|
assert(!second.isNull());
|
|
std::copy(typeVars.begin(), typeVars.end(), getTypeVariablesBuffer().begin());
|
|
}
|
|
|
|
ProtocolDecl *Constraint::getProtocol() const {
|
|
assert((Kind == ConstraintKind::ConformsTo ||
|
|
Kind == ConstraintKind::SelfObjectOfProtocol)
|
|
&& "Not a conformance constraint");
|
|
return Types.Second->castTo<ProtocolType>()->getDecl();
|
|
}
|
|
|
|
Constraint *Constraint::clone(ConstraintSystem &cs) const {
|
|
switch (getKind()) {
|
|
case ConstraintKind::Bind:
|
|
case ConstraintKind::Equal:
|
|
case ConstraintKind::BindParam:
|
|
case ConstraintKind::Subtype:
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
case ConstraintKind::ArgumentConversion:
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentConversion:
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::CheckedCast:
|
|
case ConstraintKind::DynamicTypeOf:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
case ConstraintKind::ApplicableFunction:
|
|
case ConstraintKind::OptionalObject:
|
|
return create(cs, getKind(), getFirstType(), getSecondType(),
|
|
DeclName(), getLocator());
|
|
|
|
case ConstraintKind::BindOverload:
|
|
return createBindOverload(cs, getFirstType(), getOverloadChoice(),
|
|
getLocator());
|
|
|
|
case ConstraintKind::ValueMember:
|
|
case ConstraintKind::UnresolvedValueMember:
|
|
case ConstraintKind::TypeMember:
|
|
return create(cs, getKind(), getFirstType(), Type(), getMember(),
|
|
getLocator());
|
|
|
|
case ConstraintKind::Defaultable:
|
|
return create(cs, getKind(), getFirstType(), getSecondType(),
|
|
getMember(), getLocator());
|
|
|
|
case ConstraintKind::Archetype:
|
|
case ConstraintKind::Class:
|
|
case ConstraintKind::BridgedToObjectiveC:
|
|
return create(cs, getKind(), getFirstType(), Type(), DeclName(),
|
|
getLocator());
|
|
|
|
case ConstraintKind::Disjunction:
|
|
return createDisjunction(cs, getNestedConstraints(), getLocator());
|
|
}
|
|
}
|
|
|
|
void Constraint::print(llvm::raw_ostream &Out, SourceManager *sm) const {
|
|
if (Kind == ConstraintKind::Disjunction) {
|
|
Out << "disjunction";
|
|
if (shouldRememberChoice())
|
|
Out << " (remembered)";
|
|
if (Locator) {
|
|
Out << " [[";
|
|
Locator->dump(sm, Out);
|
|
Out << "]]";
|
|
}
|
|
Out << ":";
|
|
|
|
bool first = true;
|
|
for (auto constraint : getNestedConstraints()) {
|
|
if (first)
|
|
first = false;
|
|
else
|
|
Out << " or ";
|
|
|
|
constraint->print(Out, sm);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
Types.First->print(Out);
|
|
|
|
bool skipSecond = false;
|
|
|
|
switch (Kind) {
|
|
case ConstraintKind::Bind: Out << " bind "; break;
|
|
case ConstraintKind::Equal: Out << " equal "; break;
|
|
case ConstraintKind::BindParam: Out << " bind param "; break;
|
|
case ConstraintKind::Subtype: Out << " subtype "; break;
|
|
case ConstraintKind::Conversion: Out << " conv "; break;
|
|
case ConstraintKind::ExplicitConversion: Out << " expl conv "; break;
|
|
case ConstraintKind::ArgumentConversion: Out << " arg conv "; break;
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
Out << " arg tuple conv "; break;
|
|
case ConstraintKind::OperatorArgumentTupleConversion:
|
|
Out << " operator arg tuple conv "; break;
|
|
case ConstraintKind::OperatorArgumentConversion:
|
|
Out << " operator arg conv "; break;
|
|
case ConstraintKind::ConformsTo: Out << " conforms to "; break;
|
|
case ConstraintKind::CheckedCast: Out << " checked cast to "; break;
|
|
case ConstraintKind::SelfObjectOfProtocol: Out << " Self type of "; break;
|
|
case ConstraintKind::ApplicableFunction: Out << " applicable fn "; break;
|
|
case ConstraintKind::DynamicTypeOf: Out << " dynamicType type of "; break;
|
|
case ConstraintKind::OptionalObject:
|
|
Out << " optional with object type "; break;
|
|
case ConstraintKind::BindOverload: {
|
|
Out << " bound to ";
|
|
auto overload = getOverloadChoice();
|
|
auto printDecl = [&] {
|
|
auto decl = overload.getDecl();
|
|
decl->dumpRef(Out);
|
|
Out << " : " << decl->getType();
|
|
if (!sm || !decl->getLoc().isValid()) return;
|
|
Out << " at ";
|
|
decl->getLoc().print(Out, *sm);
|
|
};
|
|
|
|
switch (overload.getKind()) {
|
|
case OverloadChoiceKind::Decl:
|
|
Out << "decl ";
|
|
printDecl();
|
|
break;
|
|
case OverloadChoiceKind::TypeDecl:
|
|
Out << "type decl ";
|
|
printDecl();
|
|
break;
|
|
case OverloadChoiceKind::DeclViaDynamic:
|
|
Out << "decl-via-dynamic ";
|
|
printDecl();
|
|
break;
|
|
case OverloadChoiceKind::DeclViaBridge:
|
|
Out << "decl-via-bridge ";
|
|
printDecl();
|
|
break;
|
|
case OverloadChoiceKind::DeclViaUnwrappedOptional:
|
|
Out << "decl-via-unwrapped-optional ";
|
|
printDecl();
|
|
break;
|
|
case OverloadChoiceKind::BaseType:
|
|
Out << "base type";
|
|
break;
|
|
case OverloadChoiceKind::TupleIndex:
|
|
Out << "tuple index " << overload.getTupleIndex();
|
|
break;
|
|
}
|
|
|
|
skipSecond = true;
|
|
break;
|
|
}
|
|
|
|
case ConstraintKind::ValueMember:
|
|
Out << "[." << Types.Member << ": value] == ";
|
|
break;
|
|
case ConstraintKind::UnresolvedValueMember:
|
|
Out << "[(implicit) ." << Types.Member << ": value] == ";
|
|
break;
|
|
case ConstraintKind::TypeMember:
|
|
Out << "[." << Types.Member << ": type] == ";
|
|
break;
|
|
case ConstraintKind::Archetype:
|
|
Out << " is an archetype";
|
|
skipSecond = true;
|
|
break;
|
|
case ConstraintKind::Class:
|
|
Out << " is a class";
|
|
skipSecond = true;
|
|
break;
|
|
case ConstraintKind::BridgedToObjectiveC:
|
|
Out << " is bridged to an Objective-C type";
|
|
skipSecond = true;
|
|
break;
|
|
case ConstraintKind::Defaultable:
|
|
Out << " can default to ";
|
|
break;
|
|
case ConstraintKind::Disjunction:
|
|
llvm_unreachable("disjunction handled above");
|
|
}
|
|
|
|
if (!skipSecond)
|
|
Types.Second->print(Out);
|
|
|
|
if (auto restriction = getRestriction()) {
|
|
Out << ' ' << getName(*restriction);
|
|
}
|
|
|
|
if (auto fix = getFix()) {
|
|
Out << ' ';
|
|
fix->print(Out, nullptr);
|
|
}
|
|
|
|
if (Locator) {
|
|
Out << " [[";
|
|
Locator->dump(sm, Out);
|
|
Out << "]];";
|
|
}
|
|
}
|
|
|
|
void Constraint::dump(SourceManager *sm) const {
|
|
print(llvm::errs(), sm);
|
|
llvm::errs() << "\n";
|
|
}
|
|
|
|
void Constraint::dump(ConstraintSystem *CS) const {
|
|
// Print all type variables as $T0 instead of _ here.
|
|
llvm::SaveAndRestore<bool> X(CS->getASTContext().LangOpts.
|
|
DebugConstraintSolver, true);
|
|
|
|
dump(&CS->getASTContext().SourceMgr);
|
|
}
|
|
|
|
|
|
StringRef swift::constraints::getName(ConversionRestrictionKind kind) {
|
|
switch (kind) {
|
|
case ConversionRestrictionKind::TupleToTuple:
|
|
return "[tuple-to-tuple]";
|
|
case ConversionRestrictionKind::ScalarToTuple:
|
|
return "[scalar-to-tuple]";
|
|
case ConversionRestrictionKind::TupleToScalar:
|
|
return "[tuple-to-scalar]";
|
|
case ConversionRestrictionKind::DeepEquality:
|
|
return "[deep equality]";
|
|
case ConversionRestrictionKind::Superclass:
|
|
return "[superclass]";
|
|
case ConversionRestrictionKind::LValueToRValue:
|
|
return "[lvalue-to-rvalue]";
|
|
case ConversionRestrictionKind::Existential:
|
|
return "[existential]";
|
|
case ConversionRestrictionKind::MetatypeToExistentialMetatype:
|
|
return "[metatype-to-existential-metatype]";
|
|
case ConversionRestrictionKind::ValueToOptional:
|
|
return "[value-to-optional]";
|
|
case ConversionRestrictionKind::OptionalToOptional:
|
|
return "[optional-to-optional]";
|
|
case ConversionRestrictionKind::ImplicitlyUnwrappedOptionalToOptional:
|
|
return "[unchecked-optional-to-optional]";
|
|
case ConversionRestrictionKind::OptionalToImplicitlyUnwrappedOptional:
|
|
return "[optional-to-unchecked-optional]";
|
|
case ConversionRestrictionKind::ClassMetatypeToAnyObject:
|
|
return "[class-metatype-to-object]";
|
|
case ConversionRestrictionKind::ExistentialMetatypeToAnyObject:
|
|
return "[existential-metatype-to-object]";
|
|
case ConversionRestrictionKind::ProtocolMetatypeToProtocolClass:
|
|
return "[protocol-metatype-to-object]";
|
|
case ConversionRestrictionKind::ArrayToPointer:
|
|
return "[array-to-pointer]";
|
|
case ConversionRestrictionKind::StringToPointer:
|
|
return "[string-to-pointer]";
|
|
case ConversionRestrictionKind::InoutToPointer:
|
|
return "[inout-to-pointer]";
|
|
case ConversionRestrictionKind::PointerToPointer:
|
|
return "[pointer-to-pointer]";
|
|
case ConversionRestrictionKind::ForceUnchecked:
|
|
return "[force-unchecked]";
|
|
case ConversionRestrictionKind::ArrayUpcast:
|
|
return "[array-upcast]";
|
|
case ConversionRestrictionKind::DictionaryUpcast:
|
|
return "[dictionary-upcast]";
|
|
case ConversionRestrictionKind::SetUpcast:
|
|
return "[set-upcast]";
|
|
case ConversionRestrictionKind::BridgeToNSError:
|
|
return "[bridge-to-nserror]";
|
|
case ConversionRestrictionKind::BridgeToObjC:
|
|
return "[bridge-to-objc]";
|
|
case ConversionRestrictionKind::BridgeFromObjC:
|
|
return "[bridge-from-objc]";
|
|
case ConversionRestrictionKind::CFTollFreeBridgeToObjC:
|
|
return "[cf-toll-free-bridge-to-objc]";
|
|
case ConversionRestrictionKind::ObjCTollFreeBridgeToCF:
|
|
return "[objc-toll-free-bridge-to-cf]";
|
|
}
|
|
llvm_unreachable("bad conversion restriction kind");
|
|
}
|
|
|
|
Fix Fix::getForcedDowncast(ConstraintSystem &cs, Type toType) {
|
|
unsigned index = cs.FixedTypes.size();
|
|
cs.FixedTypes.push_back(toType);
|
|
return Fix(FixKind::ForceDowncast, index);
|
|
}
|
|
|
|
Type Fix::getTypeArgument(ConstraintSystem &cs) const {
|
|
assert(getKind() == FixKind::ForceDowncast);
|
|
return cs.FixedTypes[Data];
|
|
}
|
|
|
|
StringRef Fix::getName(FixKind kind) {
|
|
switch (kind) {
|
|
case FixKind::None:
|
|
return "prevent fixes";
|
|
case FixKind::ForceOptional:
|
|
return "fix: force optional";
|
|
case FixKind::OptionalChaining:
|
|
return "fix: optional chaining";
|
|
case FixKind::ForceDowncast:
|
|
return "fix: force downcast";
|
|
case FixKind::AddressOf:
|
|
return "fix: add address-of";
|
|
case FixKind::OptionalToBoolean:
|
|
return "fix: convert optional to boolean";
|
|
case FixKind::CoerceToCheckedCast:
|
|
return "fix: as to as!";
|
|
}
|
|
}
|
|
|
|
void Fix::print(llvm::raw_ostream &Out, ConstraintSystem *cs) const {
|
|
Out << '[' << getName(getKind());
|
|
|
|
if (getKind() == FixKind::ForceDowncast && cs) {
|
|
Out << " as! ";
|
|
Out << getTypeArgument(*cs).getString();
|
|
}
|
|
Out << ']';
|
|
}
|
|
|
|
void Fix::dump(ConstraintSystem *cs) const {
|
|
print(llvm::errs(), cs);
|
|
llvm::errs() << "\n";
|
|
}
|
|
|
|
/// Recursively gather the set of type variables referenced by this constraint.
|
|
static void
|
|
gatherReferencedTypeVars(Constraint *constraint,
|
|
SmallVectorImpl<TypeVariableType *> &typeVars) {
|
|
switch (constraint->getKind()) {
|
|
case ConstraintKind::Disjunction:
|
|
for (auto nested : constraint->getNestedConstraints())
|
|
gatherReferencedTypeVars(nested, typeVars);
|
|
return;
|
|
|
|
case ConstraintKind::ApplicableFunction:
|
|
case ConstraintKind::Bind:
|
|
case ConstraintKind::BindParam:
|
|
case ConstraintKind::ArgumentConversion:
|
|
case ConstraintKind::Conversion:
|
|
case ConstraintKind::ExplicitConversion:
|
|
case ConstraintKind::ArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentTupleConversion:
|
|
case ConstraintKind::OperatorArgumentConversion:
|
|
case ConstraintKind::CheckedCast:
|
|
case ConstraintKind::Equal:
|
|
case ConstraintKind::Subtype:
|
|
case ConstraintKind::TypeMember:
|
|
case ConstraintKind::UnresolvedValueMember:
|
|
case ConstraintKind::ValueMember:
|
|
case ConstraintKind::DynamicTypeOf:
|
|
case ConstraintKind::OptionalObject:
|
|
case ConstraintKind::Defaultable:
|
|
constraint->getSecondType()->getTypeVariables(typeVars);
|
|
SWIFT_FALLTHROUGH;
|
|
|
|
case ConstraintKind::Archetype:
|
|
case ConstraintKind::BindOverload:
|
|
case ConstraintKind::Class:
|
|
case ConstraintKind::BridgedToObjectiveC:
|
|
case ConstraintKind::ConformsTo:
|
|
case ConstraintKind::SelfObjectOfProtocol:
|
|
constraint->getFirstType()->getTypeVariables(typeVars);
|
|
|
|
// Special case: the base type of an overloading binding.
|
|
if (constraint->getKind() == ConstraintKind::BindOverload) {
|
|
if (auto baseType = constraint->getOverloadChoice().getBaseType()) {
|
|
baseType->getTypeVariables(typeVars);
|
|
}
|
|
}
|
|
|
|
break;
|
|
}
|
|
}
|
|
|
|
/// Unique the given set of type variables.
|
|
static void uniqueTypeVariables(SmallVectorImpl<TypeVariableType *> &typeVars) {
|
|
// Remove any duplicate type variables.
|
|
llvm::SmallPtrSet<TypeVariableType *, 4> knownTypeVars;
|
|
typeVars.erase(std::remove_if(typeVars.begin(), typeVars.end(),
|
|
[&](TypeVariableType *typeVar) {
|
|
return !knownTypeVars.insert(typeVar).second;
|
|
}),
|
|
typeVars.end());
|
|
}
|
|
|
|
Constraint *Constraint::create(ConstraintSystem &cs, ConstraintKind kind,
|
|
Type first, Type second, DeclName member,
|
|
ConstraintLocator *locator) {
|
|
// Collect type variables.
|
|
SmallVector<TypeVariableType *, 4> typeVars;
|
|
if (first->hasTypeVariable())
|
|
first->getTypeVariables(typeVars);
|
|
if (second && second->hasTypeVariable())
|
|
second->getTypeVariables(typeVars);
|
|
uniqueTypeVariables(typeVars);
|
|
|
|
// Create the constraint.
|
|
unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());
|
|
void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
|
|
return new (mem) Constraint(kind, first, second, member, locator, typeVars);
|
|
}
|
|
|
|
Constraint *Constraint::createBindOverload(ConstraintSystem &cs, Type type,
|
|
OverloadChoice choice,
|
|
ConstraintLocator *locator) {
|
|
// Collect type variables.
|
|
SmallVector<TypeVariableType *, 4> typeVars;
|
|
if (type->hasTypeVariable())
|
|
type->getTypeVariables(typeVars);
|
|
if (auto baseType = choice.getBaseType()) {
|
|
baseType->getTypeVariables(typeVars);
|
|
}
|
|
|
|
// Create the constraint.
|
|
unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());
|
|
void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
|
|
return new (mem) Constraint(type, choice, locator, typeVars);
|
|
}
|
|
|
|
Constraint *Constraint::createRestricted(ConstraintSystem &cs,
|
|
ConstraintKind kind,
|
|
ConversionRestrictionKind restriction,
|
|
Type first, Type second,
|
|
ConstraintLocator *locator) {
|
|
// Collect type variables.
|
|
SmallVector<TypeVariableType *, 4> typeVars;
|
|
if (first->hasTypeVariable())
|
|
first->getTypeVariables(typeVars);
|
|
if (second->hasTypeVariable())
|
|
second->getTypeVariables(typeVars);
|
|
uniqueTypeVariables(typeVars);
|
|
|
|
// Create the constraint.
|
|
unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());
|
|
void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
|
|
return new (mem) Constraint(kind, restriction, first, second, locator,
|
|
typeVars);
|
|
}
|
|
|
|
Constraint *Constraint::createFixed(ConstraintSystem &cs, ConstraintKind kind,
|
|
Fix fix,
|
|
Type first, Type second,
|
|
ConstraintLocator *locator) {
|
|
// Collect type variables.
|
|
SmallVector<TypeVariableType *, 4> typeVars;
|
|
if (first->hasTypeVariable())
|
|
first->getTypeVariables(typeVars);
|
|
if (second->hasTypeVariable())
|
|
second->getTypeVariables(typeVars);
|
|
uniqueTypeVariables(typeVars);
|
|
|
|
// Create the constraint.
|
|
unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());
|
|
void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
|
|
return new (mem) Constraint(kind, fix, first, second, locator, typeVars);
|
|
}
|
|
|
|
Constraint *Constraint::createDisjunction(ConstraintSystem &cs,
|
|
ArrayRef<Constraint *> constraints,
|
|
ConstraintLocator *locator,
|
|
RememberChoice_t rememberChoice) {
|
|
// Unwrap any disjunctions inside the disjunction constraint; we only allow
|
|
// disjunctions at the top level.
|
|
SmallVector<TypeVariableType *, 4> typeVars;
|
|
bool unwrappedAny = false;
|
|
SmallVector<Constraint *, 1> unwrapped;
|
|
unsigned index = 0;
|
|
for (auto constraint : constraints) {
|
|
// Gather type variables from this constraint.
|
|
gatherReferencedTypeVars(constraint, typeVars);
|
|
|
|
// If we have a nested disjunction, unwrap it.
|
|
if (constraint->getKind() == ConstraintKind::Disjunction) {
|
|
// If we haven't unwrapped anything before, copy all of the constraints
|
|
// we skipped.
|
|
if (!unwrappedAny) {
|
|
unwrapped.append(constraints.begin(), constraints.begin() + index);
|
|
unwrappedAny = true;
|
|
}
|
|
|
|
// Add all of the constraints in the disjunction.
|
|
unwrapped.append(constraint->getNestedConstraints().begin(),
|
|
constraint->getNestedConstraints().end());
|
|
} else if (unwrappedAny) {
|
|
// Since we unwrapped constraints before, add this constraint.
|
|
unwrapped.push_back(constraint);
|
|
}
|
|
++index;
|
|
}
|
|
|
|
// If we unwrapped anything, our list of constraints is the unwrapped list.
|
|
if (unwrappedAny)
|
|
constraints = unwrapped;
|
|
|
|
assert(!constraints.empty() && "Empty disjunction constraint");
|
|
|
|
// If there is a single constraint, this isn't a disjunction at all.
|
|
if (constraints.size() == 1) {
|
|
assert(!rememberChoice && "simplified an important disjunction?");
|
|
return constraints.front();
|
|
}
|
|
|
|
// Create the disjunction constraint.
|
|
uniqueTypeVariables(typeVars);
|
|
unsigned size = totalSizeToAlloc<TypeVariableType*>(typeVars.size());
|
|
void *mem = cs.getAllocator().Allocate(size, alignof(Constraint));
|
|
auto disjunction = new (mem) Constraint(ConstraintKind::Disjunction,
|
|
cs.allocateCopy(constraints), locator, typeVars);
|
|
disjunction->RememberChoice = (bool) rememberChoice;
|
|
return disjunction;
|
|
}
|
|
|
|
void *Constraint::operator new(size_t bytes, ConstraintSystem& cs,
|
|
size_t alignment) {
|
|
return ::operator new (bytes, cs, alignment);
|
|
}
|