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Expr.cpp
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//===--- Expr.cpp - Swift Language Expression ASTs ------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2018 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
//
// This file implements the Expr class and subclasses.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/Expr.h"
#include "swift/Basic/Assertions.h"
#include "swift/Basic/Statistic.h"
#include "swift/Basic/Unicode.h"
#include "swift/Basic/SourceManager.h"
#include "swift/AST/ASTContext.h"
#include "swift/AST/ASTVisitor.h"
#include "swift/AST/Decl.h" // FIXME: Bad dependency
#include "swift/AST/ExistentialLayout.h"
#include "swift/AST/MacroDiscriminatorContext.h"
#include "swift/AST/ParameterList.h"
#include "swift/AST/Stmt.h"
#include "swift/AST/ASTWalker.h"
#include "swift/AST/AvailabilitySpec.h"
#include "swift/AST/PrettyStackTrace.h"
#include "swift/AST/TypeCheckRequests.h"
#include "swift/AST/TypeLoc.h"
#include "llvm/ADT/APFloat.h"
#include "llvm/ADT/PointerUnion.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/Twine.h"
using namespace swift;
#define EXPR(Id, _) \
static_assert(IsTriviallyDestructible<Id##Expr>::value, \
"Exprs are BumpPtrAllocated; the destructor is never called");
#include "swift/AST/ExprNodes.def"
//===----------------------------------------------------------------------===//
// Expr methods.
//===----------------------------------------------------------------------===//
StringRef Expr::getKindName(ExprKind K) {
switch (K) {
#define EXPR(Id, Parent) case ExprKind::Id: return #Id;
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("bad ExprKind");
}
template <class T> static SourceLoc getStartLocImpl(const T *E);
template <class T> static SourceLoc getEndLocImpl(const T *E);
template <class T> static SourceLoc getLocImpl(const T *E);
// Helper functions to check statically whether a method has been
// overridden from its implementation in Expr. The sort of thing you
// need when you're avoiding v-tables.
namespace {
template <typename ReturnType, typename Class>
constexpr bool isOverriddenFromExpr(ReturnType (Class::*)() const) {
return true;
}
template <typename ReturnType>
constexpr bool isOverriddenFromExpr(ReturnType (Expr::*)() const) {
return false;
}
template <bool IsOverridden> struct Dispatch;
/// Dispatch down to a concrete override.
template <> struct Dispatch<true> {
template <class T> static SourceLoc getStartLoc(const T *E) {
return E->getStartLoc();
}
template <class T> static SourceLoc getEndLoc(const T *E) {
return E->getEndLoc();
}
template <class T> static SourceLoc getLoc(const T *E) {
return E->getLoc();
}
template <class T> static SourceRange getSourceRange(const T *E) {
return E->getSourceRange();
}
};
/// Default implementations for when a method isn't overridden.
template <> struct Dispatch<false> {
template <class T> static SourceLoc getStartLoc(const T *E) {
return E->getSourceRange().Start;
}
template <class T> static SourceLoc getEndLoc(const T *E) {
return E->getSourceRange().End;
}
template <class T> static SourceLoc getLoc(const T *E) {
return getStartLocImpl(E);
}
template <class T> static SourceRange getSourceRange(const T *E) {
if (E->getStartLoc().isInvalid() != E->getEndLoc().isInvalid())
return SourceRange();
return { E->getStartLoc(), E->getEndLoc() };
}
};
} // end anonymous namespace
void Expr::setType(Type T) {
assert(!T || !T->hasTypeVariable() || !T->hasPlaceholder());
Ty = T;
}
void Expr::setImplicit(bool Implicit) {
assert(!isa<TypeExpr>(this) || getType() &&
"Cannot make a TypeExpr implicit without a contextual type.");
Bits.Expr.Implicit = Implicit;
}
template <class T> static SourceRange getSourceRangeImpl(const T *E) {
static_assert(isOverriddenFromExpr(&T::getSourceRange) ||
(isOverriddenFromExpr(&T::getStartLoc) &&
isOverriddenFromExpr(&T::getEndLoc)),
"Expr subclass must implement either getSourceRange() "
"or getStartLoc()/getEndLoc()");
return Dispatch<isOverriddenFromExpr(&T::getSourceRange)>::getSourceRange(E);
}
SourceRange Expr::getSourceRange() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: return getSourceRangeImpl(cast<ID##Expr>(this));
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("expression type not handled!");
}
template <class T> static SourceLoc getStartLocImpl(const T *E) {
return Dispatch<isOverriddenFromExpr(&T::getStartLoc)>::getStartLoc(E);
}
SourceLoc Expr::getStartLoc() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: return getStartLocImpl(cast<ID##Expr>(this));
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("expression type not handled!");
}
template <class T> static SourceLoc getEndLocImpl(const T *E) {
return Dispatch<isOverriddenFromExpr(&T::getEndLoc)>::getEndLoc(E);
}
SourceLoc Expr::getEndLoc() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: return getEndLocImpl(cast<ID##Expr>(this));
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("expression type not handled!");
}
template <class T> static SourceLoc getLocImpl(const T *E) {
return Dispatch<isOverriddenFromExpr(&T::getLoc)>::getLoc(E);
}
SourceLoc Expr::getLoc() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: return getLocImpl(cast<ID##Expr>(this));
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("expression type not handled!");
}
Expr *Expr::getSemanticsProvidingExpr() {
if (auto *IE = dyn_cast<IdentityExpr>(this))
return IE->getSubExpr()->getSemanticsProvidingExpr();
if (auto *TE = dyn_cast<TryExpr>(this))
return TE->getSubExpr()->getSemanticsProvidingExpr();
return this;
}
bool Expr::printConstExprValue(llvm::raw_ostream *OS,
llvm::function_ref<bool(Expr*)> additionalCheck) const {
auto print = [&](StringRef text) {
if (OS) {
*OS << text;
}
};
auto *E = getSemanticsProvidingExpr();
assert(E);
switch(getKind()) {
case ExprKind::BooleanLiteral: {
auto isTrue = cast<BooleanLiteralExpr>(E)->getValue();
print(isTrue ? "true" : "false");
return true;
}
case ExprKind::IntegerLiteral:
case ExprKind::FloatLiteral: {
const auto *NE = cast<NumberLiteralExpr>(E);
auto digits = NE->getDigitsText();
assert(!digits.empty());
if (NE->getMinusLoc().isValid()) {
print("-");
}
print(digits);
return true;
}
case ExprKind::NilLiteral: {
print("nil");
return true;
}
case ExprKind::StringLiteral: {
auto *LE = cast<StringLiteralExpr>(E);
print("\"");
print(LE->getValue());
print("\"");
return true;
}
case ExprKind::KeyPath: {
// FIXME: print keypath
print("\\.<NOT_IMPLEMENTED>");
return true;
}
case ExprKind::Array:
case ExprKind::Dictionary: {
print("[");
auto *CE = cast<CollectionExpr>(E);
for (unsigned N = CE->getNumElements(), I = 0; I != N; I ++) {
auto Ele = CE->getElement(I);
auto needComma = I + 1 != N;
if (!Ele->printConstExprValue(OS, additionalCheck)) {
return false;
}
if (needComma)
print(", ");
}
print("]");
return true;
}
case ExprKind::Tuple: {
print("(");
auto *TE = cast<TupleExpr>(E);
for (unsigned N = TE->getNumElements(), I = 0; I != N; I ++) {
auto Ele = TE->getElement(I);
auto needComma = I + 1 != N;
if (!Ele->printConstExprValue(OS, additionalCheck)) {
return false;
}
if (needComma)
print(", ");
}
print(")");
return true;
}
default:
return additionalCheck && additionalCheck(const_cast<Expr*>(this));
}
}
bool Expr::isSemanticallyConstExpr(
llvm::function_ref<bool(Expr*)> additionalCheck) const {
return printConstExprValue(nullptr, additionalCheck);
}
Expr *Expr::getValueProvidingExpr() {
Expr *E = getSemanticsProvidingExpr();
if (auto TE = dyn_cast<ForceTryExpr>(E))
return TE->getSubExpr()->getValueProvidingExpr();
// TODO:
// - tuple literal projection, which may become interestingly idiomatic
return E;
}
DeclRefExpr *Expr::getMemberOperatorRef() {
auto expr = this;
if (!expr->isImplicit()) return nullptr;
auto dotSyntax = dyn_cast<DotSyntaxCallExpr>(expr);
if (!dotSyntax) return nullptr;
auto operatorRef = dyn_cast<DeclRefExpr>(dotSyntax->getFn());
if (!operatorRef) return nullptr;
auto func = dyn_cast<FuncDecl>(operatorRef->getDecl());
if (!func) return nullptr;
if (!func->isOperator()) return nullptr;
return operatorRef;
}
ConcreteDeclRef Expr::getReferencedDecl(bool stopAtParenExpr) const {
switch (getKind()) {
// No declaration reference.
#define NO_REFERENCE(Id) case ExprKind::Id: return ConcreteDeclRef()
#define SIMPLE_REFERENCE(Id, Getter) \
case ExprKind::Id: \
return cast<Id##Expr>(this)->Getter()
#define PASS_THROUGH_REFERENCE(Id, GetSubExpr) \
case ExprKind::Id: \
if (auto sub = cast<Id##Expr>(this)->GetSubExpr()) \
return sub->getReferencedDecl(stopAtParenExpr); \
return ConcreteDeclRef();
NO_REFERENCE(Error);
SIMPLE_REFERENCE(NilLiteral, getInitializer);
SIMPLE_REFERENCE(IntegerLiteral, getInitializer);
SIMPLE_REFERENCE(FloatLiteral, getInitializer);
SIMPLE_REFERENCE(BooleanLiteral, getInitializer);
SIMPLE_REFERENCE(StringLiteral, getInitializer);
SIMPLE_REFERENCE(InterpolatedStringLiteral, getInitializer);
NO_REFERENCE(RegexLiteral);
NO_REFERENCE(ObjectLiteral);
NO_REFERENCE(MagicIdentifierLiteral);
NO_REFERENCE(DiscardAssignment);
NO_REFERENCE(LazyInitializer);
NO_REFERENCE(SingleValueStmt);
SIMPLE_REFERENCE(DeclRef, getDeclRef);
SIMPLE_REFERENCE(SuperRef, getSelf);
NO_REFERENCE(Type);
SIMPLE_REFERENCE(OtherConstructorDeclRef, getDeclRef);
PASS_THROUGH_REFERENCE(DotSyntaxBaseIgnored, getRHS);
// FIXME: Return multiple results?
case ExprKind::OverloadedDeclRef:
return ConcreteDeclRef();
NO_REFERENCE(UnresolvedDeclRef);
SIMPLE_REFERENCE(MemberRef, getMember);
SIMPLE_REFERENCE(DynamicMemberRef, getMember);
SIMPLE_REFERENCE(DynamicSubscript, getMember);
PASS_THROUGH_REFERENCE(UnresolvedSpecialize, getSubExpr);
NO_REFERENCE(UnresolvedMember);
NO_REFERENCE(UnresolvedDot);
NO_REFERENCE(Sequence);
case ExprKind::Paren:
if (stopAtParenExpr) return ConcreteDeclRef();
return cast<ParenExpr>(this)
->getSubExpr()->getReferencedDecl(stopAtParenExpr);
PASS_THROUGH_REFERENCE(UnresolvedMemberChainResult, getSubExpr);
PASS_THROUGH_REFERENCE(DotSelf, getSubExpr);
PASS_THROUGH_REFERENCE(Await, getSubExpr);
PASS_THROUGH_REFERENCE(Unsafe, getSubExpr);
PASS_THROUGH_REFERENCE(Consume, getSubExpr);
PASS_THROUGH_REFERENCE(Copy, getSubExpr);
PASS_THROUGH_REFERENCE(Borrow, getSubExpr);
PASS_THROUGH_REFERENCE(Try, getSubExpr);
PASS_THROUGH_REFERENCE(ForceTry, getSubExpr);
PASS_THROUGH_REFERENCE(OptionalTry, getSubExpr);
PASS_THROUGH_REFERENCE(ExtractFunctionIsolation, getFunctionExpr);
NO_REFERENCE(Tuple);
SIMPLE_REFERENCE(Array, getInitializer);
SIMPLE_REFERENCE(Dictionary, getInitializer);
case ExprKind::Subscript: {
auto subscript = cast<SubscriptExpr>(this);
if (subscript->hasDecl()) return subscript->getDecl();
return ConcreteDeclRef();
}
NO_REFERENCE(KeyPathApplication);
NO_REFERENCE(TupleElement);
NO_REFERENCE(CaptureList);
NO_REFERENCE(Closure);
PASS_THROUGH_REFERENCE(AutoClosure, getSingleExpressionBody);
PASS_THROUGH_REFERENCE(InOut, getSubExpr);
NO_REFERENCE(VarargExpansion);
NO_REFERENCE(PackExpansion);
NO_REFERENCE(PackElement);
NO_REFERENCE(MaterializePack);
NO_REFERENCE(DynamicType);
PASS_THROUGH_REFERENCE(RebindSelfInConstructor, getSubExpr);
NO_REFERENCE(OpaqueValue);
NO_REFERENCE(PropertyWrapperValuePlaceholder);
NO_REFERENCE(AppliedPropertyWrapper);
NO_REFERENCE(DefaultArgument);
PASS_THROUGH_REFERENCE(BindOptional, getSubExpr);
PASS_THROUGH_REFERENCE(OptionalEvaluation, getSubExpr);
PASS_THROUGH_REFERENCE(ForceValue, getSubExpr);
PASS_THROUGH_REFERENCE(OpenExistential, getSubExpr);
NO_REFERENCE(Call);
NO_REFERENCE(PrefixUnary);
NO_REFERENCE(PostfixUnary);
NO_REFERENCE(Binary);
NO_REFERENCE(DotSyntaxCall);
NO_REFERENCE(MakeTemporarilyEscapable);
NO_REFERENCE(ConstructorRefCall);
PASS_THROUGH_REFERENCE(Load, getSubExpr);
NO_REFERENCE(DestructureTuple);
NO_REFERENCE(UnresolvedTypeConversion);
PASS_THROUGH_REFERENCE(ABISafeConversion, getSubExpr);
PASS_THROUGH_REFERENCE(FunctionConversion, getSubExpr);
PASS_THROUGH_REFERENCE(CovariantFunctionConversion, getSubExpr);
PASS_THROUGH_REFERENCE(CovariantReturnConversion, getSubExpr);
PASS_THROUGH_REFERENCE(MetatypeConversion, getSubExpr);
PASS_THROUGH_REFERENCE(CollectionUpcastConversion, getSubExpr);
PASS_THROUGH_REFERENCE(Erasure, getSubExpr);
PASS_THROUGH_REFERENCE(AnyHashableErasure, getSubExpr);
PASS_THROUGH_REFERENCE(DerivedToBase, getSubExpr);
PASS_THROUGH_REFERENCE(ArchetypeToSuper, getSubExpr);
PASS_THROUGH_REFERENCE(InjectIntoOptional, getSubExpr);
PASS_THROUGH_REFERENCE(ClassMetatypeToObject, getSubExpr);
PASS_THROUGH_REFERENCE(ExistentialMetatypeToObject, getSubExpr);
PASS_THROUGH_REFERENCE(ProtocolMetatypeToObject, getSubExpr);
PASS_THROUGH_REFERENCE(InOutToPointer, getSubExpr);
PASS_THROUGH_REFERENCE(ArrayToPointer, getSubExpr);
PASS_THROUGH_REFERENCE(StringToPointer, getSubExpr);
PASS_THROUGH_REFERENCE(PointerToPointer, getSubExpr);
PASS_THROUGH_REFERENCE(ForeignObjectConversion, getSubExpr);
PASS_THROUGH_REFERENCE(UnevaluatedInstance, getSubExpr);
PASS_THROUGH_REFERENCE(DifferentiableFunction, getSubExpr);
PASS_THROUGH_REFERENCE(LinearFunction, getSubExpr);
PASS_THROUGH_REFERENCE(DifferentiableFunctionExtractOriginal, getSubExpr);
PASS_THROUGH_REFERENCE(LinearFunctionExtractOriginal, getSubExpr);
PASS_THROUGH_REFERENCE(LinearToDifferentiableFunction, getSubExpr);
PASS_THROUGH_REFERENCE(BridgeToObjC, getSubExpr);
PASS_THROUGH_REFERENCE(BridgeFromObjC, getSubExpr);
PASS_THROUGH_REFERENCE(ConditionalBridgeFromObjC, getSubExpr);
PASS_THROUGH_REFERENCE(UnderlyingToOpaque, getSubExpr);
PASS_THROUGH_REFERENCE(Unreachable, getSubExpr);
PASS_THROUGH_REFERENCE(ActorIsolationErasure, getSubExpr);
PASS_THROUGH_REFERENCE(UnsafeCast, getSubExpr);
NO_REFERENCE(Coerce);
NO_REFERENCE(ForcedCheckedCast);
NO_REFERENCE(ConditionalCheckedCast);
NO_REFERENCE(Is);
NO_REFERENCE(Arrow);
NO_REFERENCE(Ternary);
NO_REFERENCE(EnumIsCase);
NO_REFERENCE(Assign);
NO_REFERENCE(CodeCompletion);
NO_REFERENCE(UnresolvedPattern);
NO_REFERENCE(EditorPlaceholder);
NO_REFERENCE(ObjCSelector);
NO_REFERENCE(KeyPath);
NO_REFERENCE(KeyPathDot);
PASS_THROUGH_REFERENCE(CurrentContextIsolation, getActor);
NO_REFERENCE(Tap);
NO_REFERENCE(TypeJoin);
SIMPLE_REFERENCE(MacroExpansion, getMacroRef);
NO_REFERENCE(TypeValue);
#undef SIMPLE_REFERENCE
#undef NO_REFERENCE
#undef PASS_THROUGH_REFERENCE
}
return ConcreteDeclRef();
}
/// Enumerate each immediate child expression of this node, invoking the
/// specific functor on it. This ignores statements and other non-expression
/// children.
void Expr::
forEachImmediateChildExpr(llvm::function_ref<Expr *(Expr *)> callback) {
struct ChildWalker : ASTWalker {
llvm::function_ref<Expr *(Expr *)> callback;
Expr *ThisNode;
/// Only walk the arguments of a macro, to represent the source as written.
MacroWalking getMacroWalkingBehavior() const override {
return MacroWalking::Arguments;
}
ChildWalker(llvm::function_ref<Expr *(Expr *)> callback, Expr *ThisNode)
: callback(callback), ThisNode(ThisNode) {}
PreWalkResult<Expr *> walkToExprPre(Expr *E) override {
// When looking at the current node, of course we want to enter it. We
// also don't want to enumerate it.
if (E == ThisNode)
return Action::Continue(E);
// Otherwise we must be a child of our expression, enumerate it!
E = callback(E);
if (!E)
return Action::Stop();
// We're only interested in the immediate children, so don't walk any
// further.
return Action::SkipNode(E);
}
PreWalkResult<Stmt *> walkToStmtPre(Stmt *S) override {
return Action::SkipNode(S);
}
PreWalkResult<Pattern *> walkToPatternPre(Pattern *P) override {
return Action::SkipNode(P);
}
PreWalkAction walkToDeclPre(Decl *D) override {
return Action::SkipNode();
}
PreWalkAction walkToTypeReprPre(TypeRepr *T) override {
return Action::SkipNode();
}
};
this->walk(ChildWalker(callback, this));
}
/// Enumerate each immediate child expression of this node, invoking the
/// specific functor on it. This ignores statements and other non-expression
/// children.
void Expr::forEachChildExpr(llvm::function_ref<Expr *(Expr *)> callback) {
struct ChildWalker : ASTWalker {
llvm::function_ref<Expr *(Expr *)> callback;
/// Only walk the arguments of a macro, to represent the source as written.
MacroWalking getMacroWalkingBehavior() const override {
return MacroWalking::Arguments;
}
ChildWalker(llvm::function_ref<Expr *(Expr *)> callback)
: callback(callback) {}
PreWalkResult<Expr *> walkToExprPre(Expr *E) override {
// Enumerate the node!
E = callback(E);
if (!E)
return Action::Stop();
return Action::Continue(E);
}
PreWalkResult<Stmt *> walkToStmtPre(Stmt *S) override {
return Action::SkipNode(S);
}
PreWalkResult<Pattern *> walkToPatternPre(Pattern *P) override {
return Action::SkipNode(P);
}
PreWalkAction walkToDeclPre(Decl *D) override {
return Action::SkipNode();
}
PreWalkAction walkToTypeReprPre(TypeRepr *T) override {
return Action::SkipNode();
}
};
this->walk(ChildWalker(callback));
}
bool Expr::isTypeReference(llvm::function_ref<Type(Expr *)> getType,
llvm::function_ref<Decl *(Expr *)> getDecl) const {
Expr *expr = const_cast<Expr *>(this);
// If the result isn't a metatype, there's nothing else to do.
if (!getType(expr)->is<AnyMetatypeType>())
return false;
do {
// Skip syntax.
expr = expr->getSemanticsProvidingExpr();
// Direct reference to a type.
if (auto declRef = dyn_cast<DeclRefExpr>(expr))
if (isa<TypeDecl>(declRef->getDecl()))
return true;
if (isa<TypeExpr>(expr))
return true;
// A "." expression that refers to a member.
if (auto memberRef = dyn_cast<MemberRefExpr>(expr))
return isa<TypeDecl>(memberRef->getMember().getDecl());
// Any other expressions which might be referencing
// a declaration e.g. not yet type-checked ones like
// `UnresolvedDotExpr`.
if (auto *decl = getDecl(expr))
return isa<TypeDecl>(decl);
// When the base of a "." expression is ignored, look at the member.
if (auto ignoredDot = dyn_cast<DotSyntaxBaseIgnoredExpr>(expr)) {
expr = ignoredDot->getRHS();
continue;
}
if (auto *USE = dyn_cast<UnresolvedSpecializeExpr>(expr)) {
expr = USE->getSubExpr();
continue;
}
// Anything else is not statically derived.
return false;
} while (true);
}
bool Expr::isStaticallyDerivedMetatype(
llvm::function_ref<Type(Expr *)> getType,
llvm::function_ref<bool(Expr *)> isTypeReference) const {
// The expression must first be a type reference.
if (!isTypeReference(const_cast<Expr *>(this)))
return false;
auto type = getType(const_cast<Expr *>(this))
->castTo<AnyMetatypeType>()
->getInstanceType();
// Archetypes are never statically derived.
if (type->is<ArchetypeType>())
return false;
// Dynamic Self is never statically derived.
if (type->is<DynamicSelfType>())
return false;
// Everything else is statically derived.
return true;
}
bool Expr::isSuperExpr() const {
const Expr *expr = this;
do {
expr = expr->getSemanticsProvidingExpr();
if (isa<SuperRefExpr>(expr))
return true;
if (auto derivedToBase = dyn_cast<DerivedToBaseExpr>(expr)) {
expr = derivedToBase->getSubExpr();
continue;
}
if (auto metatypeConversion = dyn_cast<MetatypeConversionExpr>(expr)) {
expr = metatypeConversion->getSubExpr();
continue;
}
return false;
} while (true);
}
bool Expr::canAppendPostfixExpression(bool appendingPostfixOperator) const {
switch (getKind()) {
case ExprKind::Error:
case ExprKind::CodeCompletion:
case ExprKind::LazyInitializer:
return false;
case ExprKind::NilLiteral:
case ExprKind::IntegerLiteral:
case ExprKind::FloatLiteral:
case ExprKind::BooleanLiteral:
case ExprKind::StringLiteral:
case ExprKind::InterpolatedStringLiteral:
case ExprKind::RegexLiteral:
case ExprKind::MagicIdentifierLiteral:
case ExprKind::ObjCSelector:
case ExprKind::KeyPath:
case ExprKind::SingleValueStmt:
return true;
case ExprKind::ObjectLiteral:
return true;
case ExprKind::DiscardAssignment:
// Legal but pointless.
return true;
case ExprKind::DeclRef:
return !cast<DeclRefExpr>(this)->getDecl()->isOperator();
case ExprKind::SuperRef:
case ExprKind::OtherConstructorDeclRef:
case ExprKind::DotSyntaxBaseIgnored:
return true;
case ExprKind::Type:
return cast<TypeExpr>(this)->getTypeRepr()->isSimple();
case ExprKind::OverloadedDeclRef: {
auto *overloadedExpr = cast<OverloadedDeclRefExpr>(this);
if (overloadedExpr->getDecls().empty())
return false;
return !overloadedExpr->getDecls().front()->isOperator();
}
case ExprKind::UnresolvedDeclRef:
return cast<UnresolvedDeclRefExpr>(this)->getName().isOperator();
case ExprKind::MemberRef:
case ExprKind::DynamicMemberRef:
case ExprKind::DynamicSubscript:
case ExprKind::UnresolvedSpecialize:
case ExprKind::UnresolvedMember:
case ExprKind::UnresolvedDot:
case ExprKind::ExtractFunctionIsolation:
return true;
case ExprKind::Sequence:
return false;
case ExprKind::Paren:
case ExprKind::DotSelf:
case ExprKind::UnresolvedMemberChainResult:
case ExprKind::Tuple:
case ExprKind::Array:
case ExprKind::Dictionary:
case ExprKind::Subscript:
case ExprKind::KeyPathApplication:
case ExprKind::TupleElement:
return true;
case ExprKind::CaptureList:
case ExprKind::Closure:
case ExprKind::AutoClosure:
return false;
case ExprKind::DynamicType:
return true;
case ExprKind::Await:
case ExprKind::Unsafe:
case ExprKind::Consume:
case ExprKind::Copy:
case ExprKind::Borrow:
case ExprKind::Try:
case ExprKind::ForceTry:
case ExprKind::OptionalTry:
case ExprKind::InOut:
return false;
case ExprKind::RebindSelfInConstructor:
case ExprKind::OpaqueValue:
case ExprKind::PropertyWrapperValuePlaceholder:
case ExprKind::AppliedPropertyWrapper:
case ExprKind::DefaultArgument:
case ExprKind::BindOptional:
case ExprKind::OptionalEvaluation:
return false;
case ExprKind::ForceValue:
return true;
case ExprKind::OpenExistential:
case ExprKind::MakeTemporarilyEscapable:
case ExprKind::VarargExpansion:
case ExprKind::PackExpansion:
case ExprKind::PackElement:
case ExprKind::MaterializePack:
return false;
case ExprKind::Call:
case ExprKind::DotSyntaxCall:
case ExprKind::ConstructorRefCall:
return true;
case ExprKind::PostfixUnary:
return !appendingPostfixOperator;
case ExprKind::PrefixUnary:
case ExprKind::Binary:
return false;
case ExprKind::Load:
case ExprKind::ABISafeConversion:
case ExprKind::DestructureTuple:
case ExprKind::UnresolvedTypeConversion:
case ExprKind::FunctionConversion:
case ExprKind::CovariantFunctionConversion:
case ExprKind::CovariantReturnConversion:
case ExprKind::MetatypeConversion:
case ExprKind::CollectionUpcastConversion:
case ExprKind::Erasure:
case ExprKind::AnyHashableErasure:
case ExprKind::DerivedToBase:
case ExprKind::ArchetypeToSuper:
case ExprKind::InjectIntoOptional:
case ExprKind::ClassMetatypeToObject:
case ExprKind::ExistentialMetatypeToObject:
case ExprKind::ProtocolMetatypeToObject:
case ExprKind::InOutToPointer:
case ExprKind::ArrayToPointer:
case ExprKind::StringToPointer:
case ExprKind::PointerToPointer:
case ExprKind::ForeignObjectConversion:
case ExprKind::UnevaluatedInstance:
case ExprKind::DifferentiableFunction:
case ExprKind::LinearFunction:
case ExprKind::DifferentiableFunctionExtractOriginal:
case ExprKind::LinearFunctionExtractOriginal:
case ExprKind::LinearToDifferentiableFunction:
case ExprKind::EnumIsCase:
case ExprKind::ConditionalBridgeFromObjC:
case ExprKind::BridgeFromObjC:
case ExprKind::BridgeToObjC:
case ExprKind::UnderlyingToOpaque:
case ExprKind::Unreachable:
case ExprKind::ActorIsolationErasure:
case ExprKind::UnsafeCast:
case ExprKind::TypeValue:
// Implicit conversion nodes have no syntax of their own; defer to the
// subexpression.
return cast<ImplicitConversionExpr>(this)->getSubExpr()
->canAppendPostfixExpression(appendingPostfixOperator);
case ExprKind::ForcedCheckedCast:
case ExprKind::ConditionalCheckedCast:
case ExprKind::Is:
case ExprKind::Coerce:
return false;
case ExprKind::Arrow:
case ExprKind::Ternary:
case ExprKind::Assign:
case ExprKind::UnresolvedPattern:
case ExprKind::EditorPlaceholder:
case ExprKind::KeyPathDot:
case ExprKind::TypeJoin:
return false;
case ExprKind::Tap:
return true;
case ExprKind::MacroExpansion:
case ExprKind::CurrentContextIsolation:
return true;
}
llvm_unreachable("Unhandled ExprKind in switch.");
}
ArgumentList *Expr::getArgs() const {
if (auto *AE = dyn_cast<ApplyExpr>(this))
return AE->getArgs();
if (auto *SE = dyn_cast<SubscriptExpr>(this))
return SE->getArgs();
if (auto *DSE = dyn_cast<DynamicSubscriptExpr>(this))
return DSE->getArgs();
if (auto *OLE = dyn_cast<ObjectLiteralExpr>(this))
return OLE->getArgs();
if (auto *ME = dyn_cast<MacroExpansionExpr>(this))
return ME->getArgs();
return nullptr;
}
DeclNameLoc Expr::getNameLoc() const {
if (auto *DRE = dyn_cast<DeclRefExpr>(this))
return DRE->getNameLoc();
if (auto *UDRE = dyn_cast<UnresolvedDeclRefExpr>(this))
return UDRE->getNameLoc();
if (auto *ODRE = dyn_cast<OverloadedDeclRefExpr>(this))
return ODRE->getNameLoc();
if (auto *UDE = dyn_cast<UnresolvedDotExpr>(this))
return UDE->getNameLoc();
if (auto *UME = dyn_cast<UnresolvedMemberExpr>(this))
return UME->getNameLoc();
if (auto *MRE = dyn_cast<MemberRefExpr>(this))
return MRE->getNameLoc();
if (auto *DRME = dyn_cast<DynamicMemberRefExpr>(this))
return DRME->getNameLoc();
return DeclNameLoc();
}
llvm::DenseMap<Expr *, Expr *> Expr::getParentMap() {
class RecordingTraversal : public ASTWalker {
public:
llvm::DenseMap<Expr *, Expr *> &ParentMap;
/// Walk everything that's available.
MacroWalking getMacroWalkingBehavior() const override {
return MacroWalking::ArgumentsAndExpansion;
}
explicit RecordingTraversal(llvm::DenseMap<Expr *, Expr *> &parentMap)
: ParentMap(parentMap) { }
PreWalkResult<Expr *> walkToExprPre(Expr *E) override {
if (auto parent = Parent.getAsExpr())
ParentMap[E] = parent;
return Action::Continue(E);
}
};
llvm::DenseMap<Expr *, Expr *> parentMap;
RecordingTraversal traversal(parentMap);
walk(traversal);
return parentMap;
}
bool Expr::isValidParentOfTypeExpr(Expr *typeExpr) const {
// Allow references to types as a part of:
// - member references T.foo, T.Type, T.self, etc.
// - constructor calls T()
// - Subscripts T[]
//
// This is an exhaustive list of the accepted syntactic forms.
switch (getKind()) {
case ExprKind::Error:
case ExprKind::DotSelf:
case ExprKind::MemberRef:
case ExprKind::UnresolvedMember:
case ExprKind::DotSyntaxCall:
case ExprKind::ConstructorRefCall:
case ExprKind::UnresolvedDot:
case ExprKind::DotSyntaxBaseIgnored:
case ExprKind::UnresolvedSpecialize:
case ExprKind::OpenExistential:
case ExprKind::TypeValue:
return true;
// For these cases we need to ensure the type expr is the function or base.
// We do not permit e.g 'foo(T)'.
case ExprKind::Call:
return cast<CallExpr>(this)->getFn() == typeExpr;
case ExprKind::Subscript:
return cast<SubscriptExpr>(this)->getBase() == typeExpr;
case ExprKind::NilLiteral:
case ExprKind::BooleanLiteral:
case ExprKind::IntegerLiteral:
case ExprKind::FloatLiteral:
case ExprKind::StringLiteral:
case ExprKind::MagicIdentifierLiteral:
case ExprKind::InterpolatedStringLiteral:
case ExprKind::RegexLiteral:
case ExprKind::ObjectLiteral:
case ExprKind::DiscardAssignment:
case ExprKind::DeclRef:
case ExprKind::SuperRef:
case ExprKind::Type:
case ExprKind::OtherConstructorDeclRef:
case ExprKind::OverloadedDeclRef:
case ExprKind::UnresolvedDeclRef:
case ExprKind::DynamicMemberRef:
case ExprKind::DynamicSubscript:
case ExprKind::Sequence:
case ExprKind::Paren:
case ExprKind::Await:
case ExprKind::Unsafe:
case ExprKind::Consume:
case ExprKind::Copy:
case ExprKind::Borrow:
case ExprKind::UnresolvedMemberChainResult:
case ExprKind::Try:
case ExprKind::ForceTry:
case ExprKind::OptionalTry:
case ExprKind::Tuple:
case ExprKind::Array:
case ExprKind::Dictionary:
case ExprKind::KeyPathApplication:
case ExprKind::TupleElement:
case ExprKind::CaptureList:
case ExprKind::Closure:
case ExprKind::AutoClosure:
case ExprKind::InOut:
case ExprKind::VarargExpansion:
case ExprKind::PackExpansion:
case ExprKind::PackElement:
case ExprKind::MaterializePack:
case ExprKind::DynamicType:
case ExprKind::RebindSelfInConstructor:
case ExprKind::OpaqueValue:
case ExprKind::PropertyWrapperValuePlaceholder:
case ExprKind::AppliedPropertyWrapper:
case ExprKind::DefaultArgument:
case ExprKind::BindOptional:
case ExprKind::OptionalEvaluation:
case ExprKind::ForceValue:
case ExprKind::MakeTemporarilyEscapable:
case ExprKind::PrefixUnary:
case ExprKind::PostfixUnary:
case ExprKind::Binary:
case ExprKind::Load:
case ExprKind::DestructureTuple:
case ExprKind::UnresolvedTypeConversion:
case ExprKind::ABISafeConversion:
case ExprKind::FunctionConversion:
case ExprKind::CovariantFunctionConversion:
case ExprKind::CovariantReturnConversion: