Files
swift-mirror/lib/AST/Expr.cpp
2013-07-01 23:05:20 +00:00

447 lines
15 KiB
C++

//===--- Expr.cpp - Swift Language Expression ASTs ------------------------===//
//
// 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 the Expr class and subclasses.
//
//===----------------------------------------------------------------------===//
#include "swift/AST/Expr.h"
#include "swift/AST/AST.h"
#include "swift/AST/PrettyStackTrace.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;
//===----------------------------------------------------------------------===//
// Expr methods.
//===----------------------------------------------------------------------===//
// Only allow allocation of Stmts using the allocator in ASTContext.
void *Expr::operator new(size_t Bytes, ASTContext &C,
unsigned Alignment) {
return C.Allocate(Bytes, Alignment);
}
StringRef Expr::getKindName(ExprKind kind) {
switch (kind) {
#define EXPR(Id, Parent) case ExprKind::Id: return #Id;
#include "swift/AST/ExprNodes.def"
}
}
// Helper functions to verify statically whether the getSourceRange()
// function has been overridden.
typedef const char (&TwoChars)[2];
template<typename Class>
inline char checkSourceRangeType(SourceRange (Class::*)() const);
inline TwoChars checkSourceRangeType(SourceRange (Expr::*)() const);
SourceRange Expr::getSourceRange() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: \
static_assert(sizeof(checkSourceRangeType(&ID##Expr::getSourceRange)) == 1, \
#ID "Expr is missing getSourceRange()"); \
return cast<ID##Expr>(this)->getSourceRange();
#include "swift/AST/ExprNodes.def"
}
llvm_unreachable("expression type not handled!");
}
/// getLoc - Return the caret location of the expression.
SourceLoc Expr::getLoc() const {
switch (getKind()) {
#define EXPR(ID, PARENT) \
case ExprKind::ID: \
if (&Expr::getLoc != &ID##Expr::getLoc) \
return cast<ID##Expr>(this)->getLoc(); \
break;
#include "swift/AST/ExprNodes.def"
}
return getStartLoc();
}
Expr *Expr::getSemanticsProvidingExpr() {
if (ParenExpr *PE = dyn_cast<ParenExpr>(this))
return PE->getSubExpr()->getSemanticsProvidingExpr();
if (DefaultValueExpr *DE = dyn_cast<DefaultValueExpr>(this))
return DE->getSubExpr()->getSemanticsProvidingExpr();
return this;
}
Expr *Expr::getValueProvidingExpr() {
// For now, this is totally equivalent to the above.
// TODO:
// - tuple literal projection, which may become interestingly idiomatic
return getSemanticsProvidingExpr();
}
bool Expr::isImplicit() const {
if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(this))
return !DRE->getLoc().isValid();
if (const ImplicitConversionExpr *ICE
= dyn_cast<ImplicitConversionExpr>(this))
return ICE->getSubExpr()->isImplicit();
if (const MemberRefExpr *memberRef = dyn_cast<MemberRefExpr>(this))
return memberRef->getNameLoc().isInvalid();
if (auto memberRef = dyn_cast<GenericMemberRefExpr>(this))
return memberRef->getNameLoc().isInvalid();
if (auto memberRef = dyn_cast<ArchetypeMemberRefExpr>(this))
return memberRef->getNameLoc().isInvalid();
if (const MetatypeExpr *metatype = dyn_cast<MetatypeExpr>(this))
return metatype->getLoc().isInvalid();
if (const ApplyExpr *apply = dyn_cast<ApplyExpr>(this))
return apply->getArg() && apply->getArg()->isImplicit();
if (const TupleExpr *tuple = dyn_cast<TupleExpr>(this)) {
if (!tuple->getSourceRange().isInvalid())
return false;
for (auto elt : tuple->getElements()) {
if (!elt->isImplicit())
return false;
}
return true;
}
if (auto downcast = dyn_cast<ExplicitCastExpr>(this)) {
return downcast->getLoc().isInvalid() &&
downcast->getSubExpr()->isImplicit();
}
if (isa<ZeroValueExpr>(this) || isa<DefaultValueExpr>(this))
return true;
if (auto assign = dyn_cast<AssignExpr>(this))
return assign->getEqualLoc().isInvalid();
return false;
}
//===----------------------------------------------------------------------===//
// Support methods for Exprs.
//===----------------------------------------------------------------------===//
APInt IntegerLiteralExpr::getValue(StringRef Text,
unsigned BitWidth) {
llvm::APInt Value(BitWidth, 0);
// swift encodes octal differently than C
bool IsCOctal = Text.size() > 1 && Text[0] == '0' && isdigit(Text[1]);
bool Error = Text.getAsInteger(IsCOctal ? 10 : 0, Value);
assert(!Error && "Invalid IntegerLiteral formed"); (void)Error;
if (Value.getBitWidth() != BitWidth)
Value = Value.zextOrTrunc(BitWidth);
return Value;
}
APInt IntegerLiteralExpr::getValue() const {
assert(!getType().isNull() && "Semantic analysis has not completed");
return getValue(getText(),
getType()->castTo<BuiltinIntegerType>()->getBitWidth());
}
APFloat FloatLiteralExpr::getValue(StringRef Text,
const llvm::fltSemantics &Semantics) {
APFloat Val(Semantics);
APFloat::opStatus Res =
Val.convertFromString(Text, llvm::APFloat::rmNearestTiesToEven);
assert(Res != APFloat::opInvalidOp && "Sema didn't reject invalid number");
(void)Res;
return Val;
}
llvm::APFloat FloatLiteralExpr::getValue() const {
assert(!getType().isNull() && "Semantic analysis has not completed");
return getValue(getText(),
getType()->castTo<BuiltinFloatType>()->getAPFloatSemantics());
}
MemberRefExpr::MemberRefExpr(Expr *Base, SourceLoc DotLoc, VarDecl *Value,
SourceLoc NameLoc)
: Expr(ExprKind::MemberRef), Base(Base),
Value(Value), DotLoc(DotLoc), NameLoc(NameLoc) { }
ExistentialMemberRefExpr::ExistentialMemberRefExpr(Expr *Base, SourceLoc DotLoc,
ValueDecl *Value,
SourceLoc NameLoc)
: Expr(ExprKind::ExistentialMemberRef), Base(Base), Value(Value),
DotLoc(DotLoc), NameLoc(NameLoc) { }
ArchetypeMemberRefExpr::ArchetypeMemberRefExpr(Expr *Base, SourceLoc DotLoc,
ValueDecl *Value,
SourceLoc NameLoc)
: Expr(ExprKind::ArchetypeMemberRef), Base(Base), Value(Value),
DotLoc(DotLoc), NameLoc(NameLoc) { }
ArchetypeType *ArchetypeMemberRefExpr::getArchetype() const {
Type BaseTy = getBase()->getType()->getRValueType();
if (auto Meta = BaseTy->getAs<MetaTypeType>())
return Meta->getInstanceType()->castTo<ArchetypeType>();
return BaseTy->castTo<ArchetypeType>();
}
bool ArchetypeMemberRefExpr::isBaseIgnored() const {
if (isa<TypeDecl>(Value))
return true;
return false;
}
GenericMemberRefExpr::GenericMemberRefExpr(Expr *Base, SourceLoc DotLoc,
ValueDecl *Value,
SourceLoc NameLoc)
: Expr(ExprKind::GenericMemberRef), Base(Base), Value(Value),
DotLoc(DotLoc), NameLoc(NameLoc) { }
bool GenericMemberRefExpr::isBaseIgnored() const {
if (getBase()->getType()->getRValueType()->is<MetaTypeType>())
return true;
if (isa<TypeDecl>(Value))
return true;
if (auto Func = dyn_cast<FuncDecl>(Value))
return Func->isStatic();
return false;
}
Type OverloadSetRefExpr::getBaseType() const {
if (isa<OverloadedDeclRefExpr>(this))
return Type();
if (auto *DRE = dyn_cast<OverloadedMemberRefExpr>(this)) {
return DRE->getBase()->getType()->getRValueType();
}
llvm_unreachable("Unhandled overloaded set reference expression");
}
bool OverloadSetRefExpr::hasBaseObject() const {
if (Type BaseTy = getBaseType())
return !BaseTy->is<MetaTypeType>();
return false;
}
SequenceExpr *SequenceExpr::create(ASTContext &ctx, ArrayRef<Expr*> elements) {
void *Buffer = ctx.Allocate(sizeof(SequenceExpr) +
elements.size() * sizeof(Expr*),
alignof(SequenceExpr));
return ::new(Buffer) SequenceExpr(elements);
}
NewArrayExpr *NewArrayExpr::create(ASTContext &ctx, SourceLoc newLoc,
TypeLoc elementTy, ArrayRef<Bound> bounds) {
void *buffer = ctx.Allocate(sizeof(NewArrayExpr) +
bounds.size() * sizeof(Bound),
alignof(NewArrayExpr));
NewArrayExpr *E =
::new (buffer) NewArrayExpr(newLoc, elementTy, bounds.size());
memcpy(E->getBoundsBuffer(), bounds.data(), bounds.size() * sizeof(Bound));
return E;
}
SourceRange TupleExpr::getSourceRange() const {
if (LParenLoc.isValid() && !HasTrailingClosure) {
assert(RParenLoc.isValid() && "Mismatched parens?");
return SourceRange(LParenLoc, RParenLoc);
}
if (getElements().empty())
return SourceRange();
SourceLoc Start = LParenLoc.isValid()? LParenLoc
: getElement(0)->getStartLoc();
SourceLoc End = getElement(getElements().size()-1)->getEndLoc();
return SourceRange(Start, End);
}
SubscriptExpr::SubscriptExpr(Expr *Base, Expr *Index, SubscriptDecl *D)
: Expr(ExprKind::Subscript, D? D->getElementType() : Type()),
D(D), Base(Base), Index(Index) {
assert((!D ||
!D->getDeclContext()->getDeclaredTypeOfContext()->isExistentialType())
&& "use ExistentialSubscriptExpr for existential type subscript");
}
ExistentialSubscriptExpr::
ExistentialSubscriptExpr(Expr *Base, Expr *Index, SubscriptDecl *D)
: Expr(ExprKind::ExistentialSubscript, D? D->getElementType() : Type()),
D(D), Base(Base), Index(Index) {
assert(Base->getType()->getRValueType()->isExistentialType() &&
"use SubscriptExpr for non-existential type subscript");
}
ArchetypeSubscriptExpr::
ArchetypeSubscriptExpr(Expr *Base, Expr *Index, SubscriptDecl *D)
: Expr(ExprKind::ArchetypeSubscript, D? D->getElementType() : Type()),
D(D), Base(Base), Index(Index) {
assert(Base->getType()->getRValueType()->is<ArchetypeType>() &&
"use SubscriptExpr for non-archetype type subscript");
}
GenericSubscriptExpr::
GenericSubscriptExpr(Expr *Base, Expr *Index, SubscriptDecl *D)
: Expr(ExprKind::GenericSubscript, D? D->getElementType() : Type()),
D(D), Base(Base), Index(Index) {
assert(Base->getType()->getRValueType()->is<BoundGenericType>() &&
"use SubscriptExpr for non-generic type subscript");
}
ArrayRef<Pattern *> CapturingExpr::getParamPatterns() {
if (auto *func = dyn_cast<FuncExpr>(this))
return func->getArgParamPatterns();
if (auto *closure = dyn_cast<PipeClosureExpr>(this))
return closure->getParams();
if (auto *closure = dyn_cast<ClosureExpr>(this))
return closure->getParamPatterns();
llvm_unreachable("unknown capturing expr");
}
ArrayRef<const Pattern *> CapturingExpr::getParamPatterns() const {
auto patterns = const_cast<CapturingExpr*>(this)->getParamPatterns();
return ArrayRef<const Pattern *>(patterns.data(), patterns.size());
}
FuncExpr *FuncExpr::create(ASTContext &C, SourceLoc funcLoc,
ArrayRef<Pattern*> argParams,
ArrayRef<Pattern*> bodyParams,
TypeLoc fnRetType,
BraceStmt *body, DeclContext *parent) {
assert(argParams.size() == bodyParams.size());
unsigned nParams = argParams.size();
void *buf = C.Allocate(sizeof(FuncExpr) + 2 * nParams * sizeof(Pattern*),
alignof(FuncExpr));
FuncExpr *fn = ::new (buf) FuncExpr(funcLoc, nParams, fnRetType,
body, parent);
for (unsigned i = 0; i != nParams; ++i)
fn->getParamsBuffer()[i] = argParams[i];
for (unsigned i = 0; i != nParams; ++i)
fn->getParamsBuffer()[i+nParams] = bodyParams[i];
return fn;
}
SourceRange FuncExpr::getSourceRange() const {
if (auto *B = getBody())
return { FuncLoc, B->getEndLoc() };
if (FnRetType.hasLocation())
return { FuncLoc, FnRetType.getSourceRange().End };
const Pattern *LastPat = getArgParamPatterns().back();
return { FuncLoc, LastPat->getEndLoc() };
}
Type FuncExpr::getResultType(ASTContext &Ctx) const {
Type resultTy = getType();
if (!resultTy || resultTy->is<ErrorType>())
return resultTy;
for (unsigned i = 0, e = getNumParamPatterns(); i != e; ++i)
resultTy = resultTy->castTo<AnyFunctionType>()->getResult();
if (!resultTy)
resultTy = TupleType::getEmpty(Ctx);
return resultTy;
}
static ValueDecl *getCalledValue(Expr *E) {
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E))
return DRE->getDecl();
Expr *E2 = E->getValueProvidingExpr();
if (E != E2) return getCalledValue(E2);
return nullptr;
}
ValueDecl *ApplyExpr::getCalledValue() const {
return ::getCalledValue(Fn);
}
/// getImplicitThisDecl - If this FuncExpr is a non-static method in an
/// extension context, it will have a 'this' argument. This method returns it
/// if present, or returns null if not.
VarDecl *FuncExpr::getImplicitThisDecl() const {
if (getNumParamPatterns() == 0) return nullptr;
// "this" is represented as (typed_pattern (named_pattern (var_decl 'this')).
auto TP = dyn_cast<TypedPattern>(getArgParamPatterns()[0]);
if (TP == 0) return nullptr;
// The decl should be named 'this' and have no location information.
auto NP = dyn_cast<NamedPattern>(TP->getSubPattern());
if (NP && NP->getBoundName().str() == "this" && !NP->getLoc().isValid())
return NP->getDecl();
return nullptr;
}
RebindThisInConstructorExpr::RebindThisInConstructorExpr(Expr *SubExpr,
ValueDecl *This)
: Expr(ExprKind::RebindThisInConstructor,
TupleType::getEmpty(This->getASTContext())),
SubExpr(SubExpr), This(This)
{}
SourceRange PipeClosureExpr::getSourceRange() const {
return body.getPointer()->getSourceRange();
}
SourceLoc PipeClosureExpr::getLoc() const {
return body.getPointer()->getStartLoc();
}
Expr *PipeClosureExpr::getSingleExpressionBody() const {
assert(hasSingleExpressionBody() && "Not a single-expression body");
return cast<ReturnStmt>(body.getPointer()->getElements()[0].get<Stmt *>())
->getResult();
}
Type PipeClosureExpr::getResultType() const {
if (getType()->is<ErrorType>())
return getType();
return getType()->castTo<AnyFunctionType>()->getResult();
}
void PipeClosureExpr::setSingleExpressionBody(Expr *newBody) {
cast<ReturnStmt>(body.getPointer()->getElements()[0].get<Stmt *>())
->setResult(newBody);
}
SourceRange AssignExpr::getSourceRange() const {
if (isFolded())
return SourceRange(Dest->getStartLoc(), Src->getEndLoc());
return EqualLoc;
}
SourceLoc UnresolvedPatternExpr::getLoc() const { return subPattern->getLoc(); }
SourceRange UnresolvedPatternExpr::getSourceRange() const {
return subPattern->getSourceRange();
}