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[ConstraintSystem] Diagnose missing explicit calls in assignment #24407

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Merged
merged 2 commits into from
May 1, 2019
Merged

[ConstraintSystem] Diagnose missing explicit calls in assignment #24407

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0ad0a84
[ConstraintSystem] NFC: Move `repairFailure` to be a member of Constr…
xedin Apr 30, 2019
b82a8c5
[ConstraintSystem] Diagnose missing explicit calls in assignment
xedin May 1, 2019
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11 changes: 11 additions & 0 deletions lib/Sema/CSDiagnostics.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -1589,6 +1589,17 @@ bool MissingCallFailure::diagnoseAsError() {
}
}

if (auto *AE = dyn_cast<AssignExpr>(baseExpr)) {
auto *srcExpr = AE->getSrc();
if (auto *fnType = getType(srcExpr)->getAs<FunctionType>()) {
emitDiagnostic(srcExpr->getLoc(), diag::missing_nullary_call,
fnType->getResult())
.highlight(srcExpr->getSourceRange())
.fixItInsertAfter(srcExpr->getEndLoc(), "()");
return true;
}
}

emitDiagnostic(baseExpr->getLoc(), diag::did_not_call_function_value)
.fixItInsertAfter(insertLoc, "()");
return true;
Expand Down
64 changes: 42 additions & 22 deletions lib/Sema/CSSimplify.cpp
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Expand Up @@ -1978,24 +1978,44 @@ static ConstraintFix *fixRequirementFailure(ConstraintSystem &cs, Type type1,
/// Attempt to repair typing failures and record fixes if needed.
/// \return true if at least some of the failures has been repaired
/// successfully, which allows type matcher to continue.
static bool
repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
SmallVectorImpl<RestrictionOrFix> &conversionsOrFixes,
ConstraintLocatorBuilder locator) {
bool ConstraintSystem::repairFailures(
Type lhs, Type rhs, SmallVectorImpl<RestrictionOrFix> &conversionsOrFixes,
ConstraintLocatorBuilder locator) {
SmallVector<LocatorPathElt, 4> path;
auto *anchor = locator.getLocatorParts(path);

if (path.empty()) {
if (!anchor)
return false;

// If method reference forms a value type of the key path,
// there is going to be a constraint to match result of the
// member lookup to the generic parameter `V` of *KeyPath<R, V>
// type associated with key path expression, which we need to
// fix-up here.
if (anchor && isa<KeyPathExpr>(anchor)) {
if (isa<KeyPathExpr>(anchor)) {
auto *fnType = lhs->getAs<FunctionType>();
if (fnType && fnType->getResult()->isEqual(rhs))
return true;
}

if (isa<AssignExpr>(anchor)) {
if (auto *fnType = lhs->getAs<FunctionType>()) {
// If left-hand side is a function type but right-hand
// side isn't, let's check it would be possible to fix
// this by forming an explicit call.
if (!rhs->is<FunctionType>() && !rhs->isVoid() &&
fnType->getNumParams() == 0 &&
matchTypes(fnType->getResult(), rhs, ConstraintKind::Conversion,
TypeMatchFlags::TMF_ApplyingFix, locator)
.isSuccess()) {
conversionsOrFixes.push_back(
InsertExplicitCall::create(*this, getConstraintLocator(locator)));
return true;
}
}
}

return false;
}

Expand All @@ -2005,14 +2025,14 @@ repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
case ConstraintLocator::ApplyArgToParam: {
if (lhs->getOptionalObjectType() && !rhs->getOptionalObjectType()) {
conversionsOrFixes.push_back(
ForceOptional::create(cs, lhs, lhs->getOptionalObjectType(),
cs.getConstraintLocator(locator)));
ForceOptional::create(*this, lhs, lhs->getOptionalObjectType(),
getConstraintLocator(locator)));
}
break;
}

case ConstraintLocator::FunctionArgument: {
auto *argLoc = cs.getConstraintLocator(
auto *argLoc = getConstraintLocator(
locator.withPathElement(LocatorPathElt::getSynthesizedArgument(0)));

// Let's drop the last element which points to a single argument
Expand All @@ -2023,7 +2043,7 @@ repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
path.back().getKind() == ConstraintLocator::ContextualType))
return false;

auto arg = llvm::find_if(cs.getTypeVariables(),
auto arg = llvm::find_if(getTypeVariables(),
[&argLoc](const TypeVariableType *typeVar) {
return typeVar->getImpl().getLocator() == argLoc;
});
Expand All @@ -2040,27 +2060,27 @@ repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
//
// But if `T.Element` didn't get resolved to `Void` we'd like
// to diagnose this as a missing argument which can't be ignored.
if (arg != cs.getTypeVariables().end()) {
if (arg != getTypeVariables().end()) {
auto fnType = FunctionType::get({FunctionType::Param(lhs)},
cs.getASTContext().TheEmptyTupleType);
getASTContext().TheEmptyTupleType);
conversionsOrFixes.push_back(AddMissingArguments::create(
cs, fnType, {FunctionType::Param(*arg)},
cs.getConstraintLocator(anchor, path,
/*summaryFlags=*/0)));
*this, fnType, {FunctionType::Param(*arg)},
getConstraintLocator(anchor, path,
/*summaryFlags=*/0)));
}
break;
}

case ConstraintLocator::TypeParameterRequirement:
case ConstraintLocator::ConditionalRequirement: {
if (auto *fix = fixRequirementFailure(cs, lhs, rhs, anchor, path))
if (auto *fix = fixRequirementFailure(*this, lhs, rhs, anchor, path))
conversionsOrFixes.push_back(fix);
break;
}

case ConstraintLocator::ClosureResult: {
auto *fix = ContextualMismatch::create(cs, lhs, rhs,
cs.getConstraintLocator(locator));
auto *fix = ContextualMismatch::create(*this, lhs, rhs,
getConstraintLocator(locator));
conversionsOrFixes.push_back(fix);
break;
}
Expand All @@ -2070,14 +2090,14 @@ repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
// between them are mutability and/or root, value type mismatch.
if (isKnownKeyPathType(lhs) && isKnownKeyPathType(rhs)) {
auto *fix = KeyPathContextualMismatch::create(
cs, lhs, rhs, cs.getConstraintLocator(locator));
*this, lhs, rhs, getConstraintLocator(locator));
conversionsOrFixes.push_back(fix);
}

if (lhs->is<FunctionType>() && !rhs->is<AnyFunctionType>() &&
isa<ClosureExpr>(anchor)) {
auto *fix = ContextualMismatch::create(cs, lhs, rhs,
cs.getConstraintLocator(locator));
auto *fix = ContextualMismatch::create(*this, lhs, rhs,
getConstraintLocator(locator));
conversionsOrFixes.push_back(fix);
}
break;
Expand Down Expand Up @@ -2899,7 +2919,7 @@ ConstraintSystem::matchTypes(Type type1, Type type2, ConstraintKind kind,

// Attempt to repair any failures identifiable at this point.
if (attemptFixes) {
if (repairFailures(*this, type1, type2, conversionsOrFixes, locator)) {
if (repairFailures(type1, type2, conversionsOrFixes, locator)) {
if (conversionsOrFixes.empty())
return getTypeMatchSuccess();
}
Expand Down Expand Up @@ -6448,6 +6468,7 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyFixConstraint(
return result;
}

case FixKind::InsertCall:
case FixKind::SkipSameTypeRequirement:
case FixKind::SkipSuperclassRequirement:
case FixKind::ContextualMismatch:
Expand All @@ -6456,7 +6477,6 @@ ConstraintSystem::SolutionKind ConstraintSystem::simplifyFixConstraint(
}

case FixKind::UseSubscriptOperator:
case FixKind::InsertCall:
case FixKind::ExplicitlyEscaping:
case FixKind::CoerceToCheckedCast:
case FixKind::RelabelArguments:
Expand Down
7 changes: 7 additions & 0 deletions lib/Sema/ConstraintSystem.h
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Expand Up @@ -2624,6 +2624,13 @@ class ConstraintSystem {
TypeMatchResult(SolutionKind result) : Kind(result) {}
};

/// Attempt to repair typing failures and record fixes if needed.
/// \return true if at least some of the failures has been repaired
/// successfully, which allows type matcher to continue.
bool repairFailures(Type lhs, Type rhs,
SmallVectorImpl<RestrictionOrFix> &conversionsOrFixes,
ConstraintLocatorBuilder locator);

/// Subroutine of \c matchTypes(), which matches up two tuple types.
///
/// \returns the result of performing the tuple-to-tuple conversion.
Expand Down
6 changes: 3 additions & 3 deletions test/Constraints/fixes.swift
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Expand Up @@ -14,8 +14,8 @@ func f4() -> B { }
func f5(_ a: A) { }
func f6(_ a: A, _: Int) { }

func createB() -> B { } // expected-note {{found this candidate}}
func createB(_ i: Int) -> B { } // expected-note {{found this candidate}}
func createB() -> B { }
func createB(_ i: Int) -> B { }

func f7(_ a: A, _: @escaping () -> Int) -> B { }
func f7(_ a: A, _: Int) -> Int { }
Expand All @@ -37,7 +37,7 @@ func forgotCall() {
f6(f4, f2) // expected-error{{function produces expected type 'B'; did you mean to call it with '()'?}}{{8-8=()}}

// With overloading: only one succeeds.
a = createB // expected-error{{ambiguous reference to member 'createB()'}}
a = createB // expected-error{{function produces expected type 'B'; did you mean to call it with '()'?}}
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Nice!


// With overloading, pick the fewest number of fixes.
var b = f7(f4, f1) // expected-error{{function produces expected type 'B'; did you mean to call it with '()'?}}
Expand Down