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[ConstraintSystem] Simplify getFixedTypeRecursive a little. #18478

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Merged
merged 1 commit into from
Aug 3, 2018
Merged

[ConstraintSystem] Simplify getFixedTypeRecursive a little. #18478

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53 changes: 19 additions & 34 deletions lib/Sema/ConstraintSystem.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -710,54 +710,39 @@ Type ConstraintSystem::getFixedTypeRecursive(Type type,
bool wantRValue,
bool retainParens) {

// FIXME: This function doesn't strictly honor retainParens
// everywhere.
if (wantRValue)
type = type->getRValueType();

if (retainParens) {
if (wantRValue)
type = type->getRValueType();

if (auto *parenTy = dyn_cast<ParenType>(type.getPointer())) {
if (auto *parenTy = dyn_cast<ParenType>(type.getPointer())) {
if (retainParens) {
auto fixed = getFixedTypeRecursive(parenTy->getUnderlyingType(), flags,
wantRValue, retainParens);
return withParens(*this, fixed, parenTy);
}
}

while (true) {
if (wantRValue)
type = type->getRValueType();

if (auto depMemType = type->getAs<DependentMemberType>()) {
if (!depMemType->getBase()->isTypeVariableOrMember()) return type;
if (auto depMemType = type->getAs<DependentMemberType>()) {
if (!depMemType->getBase()->isTypeVariableOrMember()) return type;

// FIXME: Perform a more limited simplification?
Type newType = simplifyType(type);
if (newType.getPointer() == type.getPointer()) return type;
// FIXME: Perform a more limited simplification?
Type newType = simplifyType(type);
if (newType.getPointer() == type.getPointer()) return type;

type = newType;

// Once we've simplified a dependent member type, we need to generate a
// new constraint.
flags |= TMF_GenerateConstraints;
continue;
}

auto typeVar = type->getAs<TypeVariableType>();
if (!typeVar)
return type;
// Once we've simplified a dependent member type, we need to generate a
// new constraint.
flags |= TMF_GenerateConstraints;

if (auto fixed = getFixedType(typeVar)) {
type = fixed;
continue;
}
return getFixedTypeRecursive(newType, flags, wantRValue, retainParens);
}

if (retainParens)
if (auto *parenType = dyn_cast<ParenType>(type.getPointer()))
return withParens(*this, getRepresentative(typeVar), parenType);
if (auto typeVar = type->getAs<TypeVariableType>()) {
if (auto fixed = getFixedType(typeVar))
return getFixedTypeRecursive(fixed, flags, wantRValue, retainParens);

return getRepresentative(typeVar);
}

return type;
}

/// Does a var or subscript produce an l-value?
Expand Down