Google Git
Sign in
fuchsia / third_party / swift / 76327e097de0ea0c0818f6ac0c0d064a446056d5 / . / lib / SILGen / SILGenLValue.cpp
blob: c33d7ed7c2efd382e683a0663398e194a6f2c4b4 [file] [log] [blame]
//===--- SILGenLValue.cpp - Constructs logical lvalues for SILGen ---------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 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
//
//===----------------------------------------------------------------------===//
//
// Emission of l-value expressions and basic operations on them.
//
//===----------------------------------------------------------------------===//
#include "SILGen.h"
#include "ArgumentSource.h"
#include "LValue.h"
#include "RValue.h"
#include "Scope.h"
#include "Initialization.h"
#include "swift/AST/DiagnosticsSIL.h"
#include "swift/AST/DiagnosticsCommon.h"
#include "swift/AST/GenericEnvironment.h"
#include "swift/SIL/PrettyStackTrace.h"
#include "swift/SIL/SILArgument.h"
#include "swift/SIL/SILUndef.h"
#include "swift/SIL/TypeLowering.h"
#include "llvm/Support/raw_ostream.h"
#include "ASTVisitor.h"
using namespace swift;
using namespace Lowering;
//===----------------------------------------------------------------------===//
namespace {
struct LValueWritebackCleanup : Cleanup {
FormalEvaluationContext::stable_iterator Depth;
LValueWritebackCleanup() : Depth() {}
void emit(SILGenFunction &SGF, CleanupLocation loc) override {
auto &evaluation = *SGF.FormalEvalContext.find(Depth);
assert(evaluation.getKind() == FormalAccess::Exclusive);
auto &lvalue = static_cast<ExclusiveBorrowFormalAccess &>(evaluation);
lvalue.performWriteback(SGF, /*isFinal*/ false);
}
void dump(SILGenFunction &) const override {
#ifndef NDEBUG
llvm::errs() << "LValueWritebackCleanup\n"
<< "State: " << getState() << "Depth: " << Depth.getDepth()
<< "\n";
#endif
}
};
} // end anonymous namespace
/// Push a writeback onto the current LValueWriteback stack.
static void pushWriteback(SILGenFunction &SGF,
SILLocation loc,
std::unique_ptr<LogicalPathComponent> &&comp,
ManagedValue base,
MaterializedLValue materialized) {
assert(SGF.InWritebackScope);
// Push a cleanup to execute the writeback consistently.
auto &context = SGF.FormalEvalContext;
LValueWritebackCleanup &cleanup =
SGF.Cleanups.pushCleanup<LValueWritebackCleanup>();
CleanupHandle handle = SGF.Cleanups.getTopCleanup();
context.push<ExclusiveBorrowFormalAccess>(loc, std::move(comp), base,
materialized, handle);
cleanup.Depth = context.stable_begin();
}
//===----------------------------------------------------------------------===//
static CanType getSubstFormalRValueType(Expr *expr) {
return expr->getType()->getRValueType()->getCanonicalType();
}
static LValueTypeData getLogicalStorageTypeData(SILGenModule &SGM,
CanType substFormalType) {
AbstractionPattern origFormalType(
substFormalType.getReferenceStorageReferent());
return {
origFormalType,
substFormalType,
SGM.Types.getLoweredType(origFormalType, substFormalType).getObjectType()
};
}
static LValueTypeData getPhysicalStorageTypeData(SILGenModule &SGM,
AbstractStorageDecl *storage,
CanType substFormalType) {
auto origFormalType = SGM.Types.getAbstractionPattern(storage)
.getReferenceStorageReferentType();
return {
origFormalType,
substFormalType,
SGM.Types.getLoweredType(origFormalType, substFormalType).getObjectType()
};
}
/// SILGenLValue - An ASTVisitor for building logical lvalues.
class LLVM_LIBRARY_VISIBILITY SILGenLValue
: public Lowering::ExprVisitor<SILGenLValue, LValue, AccessKind>
{
/// A mapping from opaque value expressions to the open-existential
/// expression that determines them.
llvm::SmallDenseMap<OpaqueValueExpr *, OpenExistentialExpr *>
openedExistentials;
public:
SILGenFunction &SGF;
SILGenLValue(SILGenFunction &SGF) : SGF(SGF) {}
LValue visitRec(Expr *e, AccessKind accessKind);
/// Dummy handler to log unimplemented nodes.
LValue visitExpr(Expr *e, AccessKind accessKind);
// Nodes that form the root of lvalue paths
LValue visitDiscardAssignmentExpr(DiscardAssignmentExpr *e,
AccessKind accessKind);
LValue visitDeclRefExpr(DeclRefExpr *e, AccessKind accessKind);
LValue visitOpaqueValueExpr(OpaqueValueExpr *e, AccessKind accessKind);
// Nodes that make up components of lvalue paths
LValue visitMemberRefExpr(MemberRefExpr *e, AccessKind accessKind);
LValue visitSubscriptExpr(SubscriptExpr *e, AccessKind accessKind);
LValue visitTupleElementExpr(TupleElementExpr *e, AccessKind accessKind);
LValue visitForceValueExpr(ForceValueExpr *e, AccessKind accessKind);
LValue visitBindOptionalExpr(BindOptionalExpr *e, AccessKind accessKind);
LValue visitOpenExistentialExpr(OpenExistentialExpr *e,
AccessKind accessKind);
// Expressions that wrap lvalues
LValue visitInOutExpr(InOutExpr *e, AccessKind accessKind);
LValue visitDotSyntaxBaseIgnoredExpr(DotSyntaxBaseIgnoredExpr *e,
AccessKind accessKind);
};
static ManagedValue
emitGetIntoTemporary(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
std::unique_ptr<TemporaryInitialization> &&temporaryInit,
LogicalPathComponent &&component) {
// Emit a 'get' into the temporary.
RValue value =
std::move(component).get(SGF, loc, base, SGFContext(temporaryInit.get()));
// Force the value into the temporary if necessary.
if (!value.isInContext()) {
std::move(value).forwardInto(SGF, loc, temporaryInit.get());
}
return temporaryInit->getManagedAddress();
}
ManagedValue LogicalPathComponent::getMaterialized(SILGenFunction &SGF,
SILLocation loc,
ManagedValue base,
AccessKind kind) && {
// If this is just for a read, emit a load into a temporary memory
// location.
if (kind == AccessKind::Read) {
// Create a temporary.
std::unique_ptr<TemporaryInitialization> temporaryInit =
SGF.emitFormalAccessTemporary(loc,
SGF.getTypeLowering(getTypeOfRValue()));
return emitGetIntoTemporary(SGF, loc, base, std::move(temporaryInit),
std::move(*this));
}
assert(SGF.InWritebackScope &&
"materializing l-value for modification without writeback scope");
// Clone anything else about the component that we might need in the
// writeback.
auto clonedComponent = clone(SGF, loc);
ManagedValue temporary;
{
// Create a temporary.
std::unique_ptr<TemporaryInitialization> temporaryInit =
SGF.emitFormalAccessTemporary(loc,
SGF.getTypeLowering(getTypeOfRValue()));
FormalEvaluationScope Scope(SGF);
// Otherwise, we need to emit a get and set. Borrow the base for
// the getter.
ManagedValue getterBase =
base ? base.formalAccessBorrow(SGF, loc) : ManagedValue();
// Emit a 'get' into a temporary and then pop the borrow of base.
temporary = emitGetIntoTemporary(
SGF, loc, getterBase, std::move(temporaryInit), std::move(*this));
}
// Push a writeback for the temporary.
pushWriteback(SGF, loc, std::move(clonedComponent), base,
MaterializedLValue(temporary));
return temporary.unmanagedBorrow();
}
void LogicalPathComponent::writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) {
assert(!materialized.callback &&
"unexpected materialized lvalue with callback!");
// Load the value from the temporary unless the type is address-only
// and this is the final use, in which case we can just consume the
// value as-is.
auto temporary = materialized.temporary;
assert(temporary.getType().isAddress());
auto &tempTL = SGF.getTypeLowering(temporary.getType());
if (!tempTL.isAddressOnly() || !isFinal ||
!SGF.silConv.useLoweredAddresses()) {
if (isFinal) temporary.forward(SGF);
temporary = SGF.emitLoad(loc, temporary.getValue(), tempTL,
SGFContext(), IsTake_t(isFinal));
}
RValue rvalue(SGF, loc, getSubstFormalType(), temporary);
// Don't consume cleanups on the base if this isn't final.
if (!isFinal) { base = ManagedValue::forUnmanaged(base.getValue()); }
// Clone the component if this isn't final.
std::unique_ptr<LogicalPathComponent> clonedComponent =
(isFinal ? nullptr : clone(SGF, loc));
LogicalPathComponent *component = (isFinal ? this : &*clonedComponent);
std::move(*component).set(SGF, loc, std::move(rvalue), base);
}
InOutConversionScope::InOutConversionScope(SILGenFunction &SGF)
: SGF(SGF)
{
assert(SGF.InWritebackScope
&& "inout conversions should happen in writeback scopes");
assert(!SGF.InInOutConversionScope
&& "inout conversions should not be nested");
SGF.InInOutConversionScope = true;
}
InOutConversionScope::~InOutConversionScope() {
assert(SGF.InInOutConversionScope && "already exited conversion scope?!");
SGF.InInOutConversionScope = false;
}
void PathComponent::_anchor() {}
void PhysicalPathComponent::_anchor() {}
void LogicalPathComponent::_anchor() {}
void PathComponent::dump() const {
print(llvm::errs());
}
/// Return the LValueTypeData for a SIL value with the given AST formal type.
static LValueTypeData getValueTypeData(CanType formalType,
SILValue value) {
return {
AbstractionPattern(formalType),
formalType,
value->getType().getObjectType()
};
}
static LValueTypeData getValueTypeData(SILGenFunction &SGF, Expr *e) {
CanType formalType = getSubstFormalRValueType(e);
SILType loweredType = SGF.getLoweredType(formalType).getObjectType();
return {
AbstractionPattern(formalType),
formalType,
loweredType
};
}
/// Given the address of an optional value, unsafely project out the
/// address of the value.
static ManagedValue getAddressOfOptionalValue(SILGenFunction &SGF,
SILLocation loc,
ManagedValue optAddr,
const LValueTypeData &valueTypeData) {
// Project out the 'Some' payload.
EnumElementDecl *someDecl = SGF.getASTContext().getOptionalSomeDecl();
// If the base is +1, we want to forward the cleanup.
bool hadCleanup = optAddr.hasCleanup();
// UncheckedTakeEnumDataAddr is safe to apply to Optional, because it is
// a single-payload enum. There will (currently) never be spare bits
// embedded in the payload.
SILValue valueAddr =
SGF.B.createUncheckedTakeEnumDataAddr(loc, optAddr.forward(SGF), someDecl,
valueTypeData.TypeOfRValue.getAddressType());
// Return the value as +1 if the optional was +1.
if (hadCleanup) {
return SGF.emitManagedBufferWithCleanup(valueAddr);
} else {
return ManagedValue::forLValue(valueAddr);
}
}
namespace {
class RefElementComponent : public PhysicalPathComponent {
VarDecl *Field;
SILType SubstFieldType;
public:
RefElementComponent(VarDecl *field, SILType substFieldType,
LValueTypeData typeData)
: PhysicalPathComponent(typeData, RefElementKind),
Field(field), SubstFieldType(substFieldType) {}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(base.getType().isObject() &&
"base for ref element component must be an object");
assert(base.getType().hasReferenceSemantics() &&
"base for ref element component must be a reference type");
// Borrow the ref element addr using formal access. If we need the ref
// element addr, we will load it in this expression.
base = base.formalAccessBorrow(SGF, loc);
auto Res = SGF.B.createRefElementAddr(loc, base.getUnmanagedValue(),
Field, SubstFieldType);
return ManagedValue::forLValue(Res);
}
void print(raw_ostream &OS) const override {
OS << "RefElementComponent(" << Field->getName() << ")\n";
}
};
class TupleElementComponent : public PhysicalPathComponent {
unsigned ElementIndex;
public:
TupleElementComponent(unsigned elementIndex, LValueTypeData typeData)
: PhysicalPathComponent(typeData, TupleElementKind),
ElementIndex(elementIndex) {}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(base && "invalid value for element base");
// TODO: if the base is +1, break apart its cleanup.
auto Res = SGF.B.createTupleElementAddr(loc, base.getValue(),
ElementIndex,
getTypeOfRValue().getAddressType());
return ManagedValue::forLValue(Res);
}
void print(raw_ostream &OS) const override {
OS << "TupleElementComponent(" << ElementIndex << ")\n";
}
};
class StructElementComponent : public PhysicalPathComponent {
VarDecl *Field;
SILType SubstFieldType;
public:
StructElementComponent(VarDecl *field, SILType substFieldType,
LValueTypeData typeData)
: PhysicalPathComponent(typeData, StructElementKind),
Field(field), SubstFieldType(substFieldType) {}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(base && "invalid value for element base");
// TODO: if the base is +1, break apart its cleanup.
auto Res = SGF.B.createStructElementAddr(loc, base.getValue(),
Field, SubstFieldType);
return ManagedValue::forLValue(Res);
}
void print(raw_ostream &OS) const override {
OS << "StructElementComponent(" << Field->getName() << ")\n";
}
};
/// A physical path component which force-projects the address of
/// the value of an optional l-value.
class ForceOptionalObjectComponent : public PhysicalPathComponent {
public:
ForceOptionalObjectComponent(LValueTypeData typeData)
: PhysicalPathComponent(typeData, OptionalObjectKind) {}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
// Assert that the optional value is present and return the projected out
// payload.
return SGF.emitPreconditionOptionalHasValue(loc, base);
}
void print(raw_ostream &OS) const override {
OS << "ForceOptionalObjectComponent()\n";
}
};
/// A physical path component which projects out an opened archetype
/// from an existential.
class OpenOpaqueExistentialComponent : public PhysicalPathComponent {
static LValueTypeData getOpenedArchetypeTypeData(CanArchetypeType type) {
return {
AbstractionPattern::getOpaque(), type,
SILType::getPrimitiveObjectType(type)
};
}
public:
OpenOpaqueExistentialComponent(CanArchetypeType openedArchetype)
: PhysicalPathComponent(getOpenedArchetypeTypeData(openedArchetype),
OpenedExistentialKind) {}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(base.getType().isExistentialType() &&
"base for open existential component must be an existential");
auto addr = SGF.B.createOpenExistentialAddr(
loc, base.getLValueAddress(), getTypeOfRValue().getAddressType(),
getOpenedExistentialAccessFor(accessKind));
if (base.hasCleanup()) {
assert(false && "I believe that we should never end up here. One, we "
"assert above that base is an l-value address and we "
"state l-values don't have associated cleanup. Two, we "
"enter deinit of the buffer but don't have "
"book-keeping for the value. Three, I believe that "
"would mean to have a l-value passed at +1 which I "
"don't believe we do.");
// Leave a cleanup to deinit the existential container.
SGF.enterDeinitExistentialCleanup(base.getValue(), CanType(),
ExistentialRepresentation::Opaque);
}
SGF.setArchetypeOpeningSite(cast<ArchetypeType>(getSubstFormalType()),
addr);
return ManagedValue::forLValue(addr);
}
void print(raw_ostream &OS) const override {
OS << "OpenOpaqueExistentialComponent(" << getSubstFormalType() << ")\n";
}
};
/// A physical path component which returns a literal address.
class ValueComponent : public PhysicalPathComponent {
ManagedValue Value;
bool IsRValue;
public:
ValueComponent(ManagedValue value, LValueTypeData typeData,
bool isRValue = false) :
PhysicalPathComponent(typeData, ValueKind),
Value(value),
IsRValue(isRValue) {
assert(IsRValue || value.getType().isAddress());
}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(!base && "value component must be root of lvalue path");
return Value;
}
bool isRValue() const override {
return IsRValue;
}
void print(raw_ostream &OS) const override {
OS << "ValueComponent()\n";
}
};
} // end anonymous namespace
static bool isReadNoneFunction(const Expr *e) {
// If this is a curried call to an integer literal conversion operations, then
// we can "safely" assume it is readnone (btw, yes this is totally gross).
// This is better to be attribute driven, a la rdar://15587352.
if (auto *dre = dyn_cast<DeclRefExpr>(e)) {
DeclName name = dre->getDecl()->getFullName();
return (name.getArgumentNames().size() == 1 &&
name.getBaseName().str() == "init" &&
!name.getArgumentNames()[0].empty() &&
(name.getArgumentNames()[0].str() == "integerLiteral" ||
name.getArgumentNames()[0].str() == "_builtinIntegerLiteral"));
}
// Look through DotSyntaxCallExpr, since the literal functions are curried.
if (auto *CRCE = dyn_cast<ConstructorRefCallExpr>(e))
return isReadNoneFunction(CRCE->getFn());
return false;
}
/// Given two expressions used as indexes to the same SubscriptDecl (and thus
/// are guaranteed to have the same AST type) check to see if they are going to
/// produce the same value.
static bool areCertainlyEqualIndices(const Expr *e1, const Expr *e2) {
if (e1->getKind() != e2->getKind()) return false;
// Look through ParenExpr's.
if (auto *pe1 = dyn_cast<ParenExpr>(e1)) {
auto *pe2 = cast<ParenExpr>(e2);
return areCertainlyEqualIndices(pe1->getSubExpr(), pe2->getSubExpr());
}
// Calls are identical if the callee and operands are identical and we know
// that the call is something that is "readnone".
if (auto *ae1 = dyn_cast<ApplyExpr>(e1)) {
auto *ae2 = cast<ApplyExpr>(e2);
return areCertainlyEqualIndices(ae1->getFn(), ae2->getFn()) &&
areCertainlyEqualIndices(ae1->getArg(), ae2->getArg()) &&
isReadNoneFunction(ae1->getFn());
}
// TypeExpr's that produce the same metatype type are identical.
if (isa<TypeExpr>(e1))
return true;
if (auto *dre1 = dyn_cast<DeclRefExpr>(e1)) {
auto *dre2 = cast<DeclRefExpr>(e2);
return dre1->getDecl() == dre2->getDecl() &&
dre1->getGenericArgs() == dre2->getGenericArgs();
}
// Compare a variety of literals.
if (auto *il1 = dyn_cast<IntegerLiteralExpr>(e1))
return il1->getValue() == cast<IntegerLiteralExpr>(e2)->getValue();
if (auto *il1 = dyn_cast<FloatLiteralExpr>(e1))
return il1->getValue().bitwiseIsEqual(
cast<FloatLiteralExpr>(e2)->getValue());
if (auto *bl1 = dyn_cast<BooleanLiteralExpr>(e1))
return bl1->getValue() == cast<BooleanLiteralExpr>(e2)->getValue();
if (auto *sl1 = dyn_cast<StringLiteralExpr>(e1))
return sl1->getValue() == cast<StringLiteralExpr>(e2)->getValue();
// Compare tuple expressions.
if (auto *te1 = dyn_cast<TupleExpr>(e1)) {
auto *te2 = cast<TupleExpr>(e2);
// Easy checks: # of elements, trailing closures, element names.
if (te1->getNumElements() != te2->getNumElements() ||
te1->hasTrailingClosure() != te2->hasTrailingClosure() ||
te1->getElementNames() != te2->getElementNames()) {
return false;
}
for (unsigned i = 0, n = te1->getNumElements(); i != n; ++i) {
if (!areCertainlyEqualIndices(te1->getElement(i), te2->getElement(i)))
return false;
}
return true;
}
// Otherwise, we have no idea if they are identical.
return false;
}
namespace {
/// A helper class for implementing a component that involves
/// calling accessors.
template <class Base>
class AccessorBasedComponent : public Base {
protected:
// The VarDecl or SubscriptDecl being get/set.
AbstractStorageDecl *decl;
bool IsSuper;
bool IsDirectAccessorUse;
std::vector<Substitution> substitutions;
/// The subscript index expression. Useless
Expr *subscriptIndexExpr;
RValue subscripts;
/// AST type of the base expression, in case the accessor call
/// requires re-abstraction.
CanType baseFormalType;
struct AccessorArgs {
ArgumentSource base;
RValue subscripts;
};
/// Returns a tuple of RValues holding the accessor value, base (retained if
/// necessary), and subscript arguments, in that order.
AccessorArgs
prepareAccessorArgs(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SILDeclRef accessor) &&
{
AccessorArgs result;
if (base)
result.base = SGF.prepareAccessorBaseArg(loc, base, baseFormalType,
accessor);
if (subscripts)
result.subscripts = std::move(subscripts);
return result;
}
AccessorBasedComponent(PathComponent::KindTy kind,
AbstractStorageDecl *decl,
bool isSuper, bool isDirectAccessorUse,
SubstitutionList substitutions,
CanType baseFormalType,
LValueTypeData typeData,
Expr *subscriptIndexExpr,
RValue *optSubscripts)
: Base(typeData, kind), decl(decl),
IsSuper(isSuper), IsDirectAccessorUse(isDirectAccessorUse),
substitutions(substitutions.begin(), substitutions.end()),
subscriptIndexExpr(subscriptIndexExpr),
baseFormalType(baseFormalType)
{
if (optSubscripts)
subscripts = std::move(*optSubscripts);
}
AccessorBasedComponent(const AccessorBasedComponent &copied,
SILGenFunction &SGF,
SILLocation loc)
: Base(copied.getTypeData(), copied.getKind()),
decl(copied.decl),
IsSuper(copied.IsSuper),
IsDirectAccessorUse(copied.IsDirectAccessorUse),
substitutions(copied.substitutions),
subscriptIndexExpr(copied.subscriptIndexExpr),
subscripts(copied.subscripts.copy(SGF, loc)) ,
baseFormalType(copied.baseFormalType) {}
virtual SILDeclRef getAccessor(SILGenFunction &SGF,
AccessKind kind) const = 0;
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
SILDeclRef accessor = getAccessor(SGF, kind);
auto accessorSelf = SGF.SGM.Types.getConstantSelfParameter(accessor);
if (accessorSelf.getType() && accessorSelf.isIndirectMutating()) {
return AccessKind::ReadWrite;
} else {
return AccessKind::Read;
}
}
void printBase(raw_ostream &OS, StringRef name) const {
OS << name << "(" << decl->getName() << ")";
if (IsSuper) OS << " isSuper";
if (IsDirectAccessorUse) OS << " isDirectAccessorUse";
if (subscriptIndexExpr) {
OS << " subscript_index:\n";
subscriptIndexExpr->print(OS, 2);
}
OS << '\n';
}
};
class GetterSetterComponent
: public AccessorBasedComponent<LogicalPathComponent> {
public:
GetterSetterComponent(AbstractStorageDecl *decl,
bool isSuper, bool isDirectAccessorUse,
SubstitutionList substitutions,
CanType baseFormalType,
LValueTypeData typeData,
Expr *subscriptIndexExpr = nullptr,
RValue *subscriptIndex = nullptr)
: AccessorBasedComponent(GetterSetterKind, decl, isSuper,
isDirectAccessorUse, substitutions,
baseFormalType, typeData, subscriptIndexExpr,
subscriptIndex)
{
}
GetterSetterComponent(const GetterSetterComponent &copied,
SILGenFunction &SGF,
SILLocation loc)
: AccessorBasedComponent(copied, SGF, loc)
{
}
SILDeclRef getAccessor(SILGenFunction &SGF,
AccessKind accessKind) const override {
if (accessKind == AccessKind::Read) {
return SGF.getGetterDeclRef(decl, IsDirectAccessorUse);
} else {
return SGF.getSetterDeclRef(decl, IsDirectAccessorUse);
}
}
void set(SILGenFunction &SGF, SILLocation loc,
RValue &&value, ManagedValue base) && override {
SILDeclRef setter = SGF.getSetterDeclRef(decl, IsDirectAccessorUse);
FormalEvaluationScope scope(SGF);
// Pass in just the setter.
auto args =
std::move(*this).prepareAccessorArgs(SGF, loc, base, setter);
return SGF.emitSetAccessor(loc, setter, substitutions,
std::move(args.base), IsSuper,
IsDirectAccessorUse,
std::move(args.subscripts),
std::move(value));
}
bool shouldUseMaterializeForSet(SILGenFunction &SGF,
AccessKind accessKind) {
// If this access is for a read, we can just call the getter.
if (accessKind == AccessKind::Read)
return false;
// If the declaration is dynamic, there's no materializeForSet.
if (decl->isDynamic())
return false;
// If the declaration was imported from C, we won't gain anything
// from using materializeForSet, and furthermore, it might not
// exist.
if (decl->hasClangNode())
return false;
// If the declaration is not in type context, there's no
// materializeForSet.
if (!decl->getDeclContext()->isTypeContext())
return false;
// If the declaration is in a different resilience domain, we have
// to use materializeForSet.
//
// FIXME: Use correct ResilienceExpansion if gen is @transparent
if (!decl->hasFixedLayout(SGF.SGM.M.getSwiftModule(),
ResilienceExpansion::Maximal))
return true;
// If the declaration is dynamically dispatched through a class,
// we have to use materializeForSet.
if (auto *classDecl = dyn_cast<ClassDecl>(decl->getDeclContext())) {
if (decl->isFinal() || classDecl->isFinal())
return false;
return true;
}
// If the declaration is dynamically dispatched through a
// non-ObjC protocol, we have to use materializeForSet.
if (auto *protoDecl = dyn_cast<ProtocolDecl>(decl->getDeclContext()))
if (!protoDecl->isObjC())
return true;
return false;
}
ManagedValue getMaterialized(SILGenFunction &SGF,
SILLocation loc,
ManagedValue base,
AccessKind accessKind) && override {
if (!shouldUseMaterializeForSet(SGF, accessKind)) {
return std::move(*this).LogicalPathComponent::getMaterialized(SGF,
loc, base, accessKind);
}
assert(decl->getMaterializeForSetFunc() &&
"polymorphic storage without materializeForSet");
assert(SGF.InWritebackScope &&
"materializing l-value for modification without writeback scope");
// Allocate opaque storage for the callback to use.
SILValue callbackStorage = SGF.emitTemporaryAllocation(loc,
SILType::getPrimitiveObjectType(
SGF.getASTContext().TheUnsafeValueBufferType));
// Allocate a temporary.
SILValue buffer =
SGF.emitTemporaryAllocation(loc, getTypeOfRValue());
// Clone the component without cloning the indices. We don't actually
// consume them in writeback().
std::unique_ptr<LogicalPathComponent> clonedComponent(
[&]() -> LogicalPathComponent* {
// Steal the subscript values without copying them so that we
// can peek at them in diagnoseWritebackConflict.
//
// This is *amazingly* unprincipled.
RValue borrowedSubscripts;
RValue *optSubscripts = nullptr;
if (subscripts) {
CanType type = subscripts.getType();
SmallVector<ManagedValue, 4> values;
std::move(subscripts).getAll(values);
subscripts = RValue::withPreExplodedElements(values, type);
borrowedSubscripts = RValue::withPreExplodedElements(values, type);
optSubscripts = &borrowedSubscripts;
}
return new GetterSetterComponent(decl, IsSuper, IsDirectAccessorUse,
substitutions, baseFormalType,
getTypeData(), subscriptIndexExpr,
optSubscripts);
}());
SILDeclRef materializeForSet =
SGF.getMaterializeForSetDeclRef(decl, IsDirectAccessorUse);
MaterializedLValue materialized;
{
FormalEvaluationScope Scope(SGF);
// If the base is a +1 r-value, just borrow it for materializeForSet.
// prepareAccessorArgs will copy it if necessary.
ManagedValue borrowedBase =
base ? base.formalAccessBorrow(SGF, loc) : ManagedValue();
auto args = std::move(*this).prepareAccessorArgs(SGF, loc, borrowedBase,
materializeForSet);
materialized = SGF.emitMaterializeForSetAccessor(
loc, materializeForSet, substitutions, std::move(args.base),
IsSuper, IsDirectAccessorUse, std::move(args.subscripts), buffer,
callbackStorage);
// Mark a value-dependence on the base. We do this regardless
// of whether the base is trivial because even a trivial base
// may be value-dependent on something non-trivial.
if (base) {
SILValue temporary = materialized.temporary.getValue();
materialized.temporary = ManagedValue::forUnmanaged(
SGF.B.createMarkDependence(loc, temporary, base.getValue()));
}
}
// TODO: maybe needsWriteback should be a thin function pointer
// to which we pass the base? That would let us use direct
// access for stored properties with didSet.
pushWriteback(SGF, loc, std::move(clonedComponent), base, materialized);
return ManagedValue::forLValue(materialized.temporary.getValue());
}
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, MaterializedLValue materialized,
bool isFinal) override {
// If we don't have a callback, we don't have to conditionalize
// the writeback.
if (!materialized.callback) {
LogicalPathComponent::writeback(SGF, loc,
base, materialized,
isFinal);
return;
}
// Otherwise, 'materialized' holds an optional callback and the
// callback storage.
// Mark the writeback as auto-generated so that we don't get
// warnings if we manage to devirtualize materializeForSet.
loc.markAutoGenerated();
SILModule &M = SGF.SGM.M;
ASTContext &ctx = SGF.getASTContext();
SILBasicBlock *contBB = SGF.createBasicBlock();
SILBasicBlock *writebackBB = SGF.createBasicBlock(SGF.B.getInsertionBB());
SGF.B.createSwitchEnum(loc, materialized.callback, /*defaultDest*/ nullptr,
{ { ctx.getOptionalSomeDecl(), writebackBB },
{ ctx.getOptionalNoneDecl(), contBB } });
// The writeback block.
SGF.B.setInsertionPoint(writebackBB); {
FullExpr scope(SGF.Cleanups, CleanupLocation::get(loc));
auto emptyTupleTy =
SILType::getPrimitiveObjectType(TupleType::getEmpty(ctx));
auto rawPointerTy = SILType::getRawPointerType(ctx);
// The callback is a BB argument from the switch_enum.
SILValue callback = writebackBB->createPHIArgument(
rawPointerTy, ValueOwnershipKind::Trivial);
// Cast the callback to the correct polymorphic function type.
SILFunctionTypeRepresentation rep;
if (isa<ProtocolDecl>(decl->getDeclContext()))
rep = SILFunctionTypeRepresentation::WitnessMethod;
else
rep = SILFunctionTypeRepresentation::Method;
auto origCallbackFnType = SGF.SGM.Types.getMaterializeForSetCallbackType(
decl, materialized.genericSig, materialized.origSelfType, rep);
auto origCallbackType = SILType::getPrimitiveObjectType(origCallbackFnType);
callback = SGF.B.createPointerToThinFunction(loc, callback, origCallbackType);
auto substCallbackFnType = origCallbackFnType->substGenericArgs(
M, substitutions);
auto substCallbackType = SILType::getPrimitiveObjectType(substCallbackFnType);
auto metatypeType =
SGF.getSILType(substCallbackFnType->getParameters().back());
// We need to borrow the base here. We can't just consume it
// because we're in conditionally-executed code (and because
// this might be a non-final use). We also need to pass it
// indirectly.
SILValue baseAddress;
SILValue baseMetatype;
if (base) {
if (base.getType().isAddress()) {
baseAddress = base.getValue();
} else {
AbstractionPattern origSelfType(materialized.genericSig,
materialized.origSelfType);
base = SGF.emitSubstToOrigValue(loc, base, origSelfType,
baseFormalType);
baseAddress = SGF.emitTemporaryAllocation(loc, base.getType());
if (base.getOwnershipKind() == ValueOwnershipKind::Guaranteed) {
SGF.B.createStoreBorrow(loc, base.getValue(), baseAddress);
} else {
SGF.B.emitStoreValueOperation(loc, base.getValue(), baseAddress,
StoreOwnershipQualifier::Init);
}
}
baseMetatype = SGF.B.createMetatype(loc, metatypeType);
// Otherwise, we have to pass something; use an empty tuple
// and an undef metatype.
} else {
baseAddress = SILUndef::get(emptyTupleTy.getAddressType(), M);
baseMetatype = SILUndef::get(metatypeType, M);
}
SILValue temporaryPointer =
SGF.B.createAddressToPointer(loc,
materialized.temporary.getValue(),
rawPointerTy);
// Apply the callback.
SGF.B.createApply(loc, callback, substCallbackType,
emptyTupleTy, substitutions, {
temporaryPointer,
materialized.callbackStorage,
baseAddress,
baseMetatype
}, false);
}
// Continue.
SGF.B.emitBlock(contBB, loc);
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && override {
SILDeclRef getter = SGF.getGetterDeclRef(decl, IsDirectAccessorUse);
FormalEvaluationScope scope(SGF);
auto args =
std::move(*this).prepareAccessorArgs(SGF, loc, base, getter);
return SGF.emitGetAccessor(loc, getter, substitutions,
std::move(args.base), IsSuper,
IsDirectAccessorUse,
std::move(args.subscripts), c);
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
LogicalPathComponent *clone = new GetterSetterComponent(*this, SGF, loc);
return std::unique_ptr<LogicalPathComponent>(clone);
}
void print(raw_ostream &OS) const override {
printBase(OS, "GetterSetterComponent");
}
/// Compare 'this' lvalue and the 'rhs' lvalue (which is guaranteed to have
/// the same dynamic PathComponent type as the receiver) to see if they are
/// identical. If so, there is a conflicting writeback happening, so emit a
/// diagnostic.
void diagnoseWritebackConflict(LogicalPathComponent *RHS,
SILLocation loc1, SILLocation loc2,
SILGenFunction &SGF) override {
auto &rhs = (GetterSetterComponent&)*RHS;
// If the decls match, then this could conflict.
if (decl != rhs.decl || IsSuper != rhs.IsSuper) return;
// If the decl is monomorphically a stored property, allow aliases.
// It could be overridden by a computed property in a subclass, but
// that's not likely enough to be worth the strictness here.
if (auto storage = dyn_cast<AbstractStorageDecl>(decl)) {
switch (storage->getStorageKind()) {
case AbstractStorageDecl::Stored:
case AbstractStorageDecl::StoredWithTrivialAccessors:
case AbstractStorageDecl::Addressed:
case AbstractStorageDecl::AddressedWithTrivialAccessors:
return;
// TODO: Stored properties with didSet accessors that don't look at the
// oldValue could also be addressed.
case AbstractStorageDecl::StoredWithObservers:
case AbstractStorageDecl::AddressedWithObservers:
break;
case AbstractStorageDecl::InheritedWithObservers:
case AbstractStorageDecl::Computed:
case AbstractStorageDecl::ComputedWithMutableAddress:
break;
}
}
// If the property is a generic requirement, allow aliases, because
// it may be conformed to using a stored property.
if (isa<ProtocolDecl>(decl->getDeclContext()))
return;
// If this is a simple property access, then we must have a conflict.
if (!subscripts) {
assert(isa<VarDecl>(decl));
SGF.SGM.diagnose(loc1, diag::writeback_overlap_property,decl->getName())
.highlight(loc1.getSourceRange());
SGF.SGM.diagnose(loc2, diag::writebackoverlap_note)
.highlight(loc2.getSourceRange());
return;
}
// Otherwise, it is a subscript, check the index values.
// If the indices are literally identical SILValue's, then there is
// clearly a conflict.
if (!subscripts.isObviouslyEqual(rhs.subscripts)) {
// If the index value doesn't lower to literally the same SILValue's,
// do some fuzzy matching to catch the common case.
if (!subscriptIndexExpr ||
!rhs.subscriptIndexExpr ||
!areCertainlyEqualIndices(subscriptIndexExpr,
rhs.subscriptIndexExpr))
return;
}
// The locations for the subscripts are almost certainly SubscriptExprs.
// If so, dig into them to produce better location info in the
// diagnostics and be able to do more precise analysis.
auto expr1 = loc1.getAsASTNode<SubscriptExpr>();
auto expr2 = loc2.getAsASTNode<SubscriptExpr>();
if (expr1 && expr2) {
SGF.SGM.diagnose(loc1, diag::writeback_overlap_subscript)
.highlight(expr1->getBase()->getSourceRange());
SGF.SGM.diagnose(loc2, diag::writebackoverlap_note)
.highlight(expr2->getBase()->getSourceRange());
} else {
SGF.SGM.diagnose(loc1, diag::writeback_overlap_subscript)
.highlight(loc1.getSourceRange());
SGF.SGM.diagnose(loc2, diag::writebackoverlap_note)
.highlight(loc2.getSourceRange());
}
}
};
class UnpinPseudoComponent : public LogicalPathComponent {
public:
UnpinPseudoComponent(const LValueTypeData &typeData)
: LogicalPathComponent(typeData, WritebackPseudoKind) {}
private:
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind accessKind) const override {
llvm_unreachable("called getBaseAccessKind on pseudo-component");
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation l) const override {
llvm_unreachable("called clone on pseudo-component");
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && override {
llvm_unreachable("called get on a pseudo-component");
}
void set(SILGenFunction &SGF, SILLocation loc,
RValue &&value, ManagedValue base) && override {
llvm_unreachable("called set on a pseudo-component");
}
ManagedValue getMaterialized(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
AccessKind accessKind) && override {
llvm_unreachable("called getMaterialized on a pseudo-component");
}
void diagnoseWritebackConflict(LogicalPathComponent *rhs,
SILLocation loc1, SILLocation loc2,
SILGenFunction &SGF) override {
// do nothing
}
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) override {
// If this is final, we can consume the owner (stored as
// 'base'). If it isn't, we actually need to retain it, because
// we've still got a release active.
SILValue baseValue = (isFinal ? base.forward(SGF) : base.getValue());
if (!isFinal)
baseValue = SGF.B.createCopyValue(loc, baseValue);
SGF.B.createStrongUnpin(loc, baseValue, SGF.B.getDefaultAtomicity());
}
void print(raw_ostream &OS) const override {
OS << "UnpinPseudoComponent";
}
};
/// A physical component which involves calling addressors.
class AddressorComponent
: public AccessorBasedComponent<PhysicalPathComponent> {
SILType SubstFieldType;
public:
AddressorComponent(AbstractStorageDecl *decl,
bool isSuper, bool isDirectAccessorUse,
SubstitutionList substitutions,
CanType baseFormalType, LValueTypeData typeData,
SILType substFieldType,
Expr *subscriptIndexExpr = nullptr,
RValue *subscriptIndex = nullptr)
: AccessorBasedComponent(AddressorKind, decl, isSuper,
isDirectAccessorUse, substitutions,
baseFormalType, typeData, subscriptIndexExpr,
subscriptIndex),
SubstFieldType(substFieldType)
{
}
SILDeclRef getAccessor(SILGenFunction &SGF,
AccessKind accessKind) const override {
return SGF.getAddressorDeclRef(decl, accessKind, IsDirectAccessorUse);
}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(SGF.InWritebackScope &&
"offsetting l-value for modification without writeback scope");
SILDeclRef addressor = SGF.getAddressorDeclRef(decl, accessKind,
IsDirectAccessorUse);
std::pair<ManagedValue, ManagedValue> result;
{
FormalEvaluationScope scope(SGF);
auto args =
std::move(*this).prepareAccessorArgs(SGF, loc, base, addressor);
result = SGF.emitAddressorAccessor(
loc, addressor, substitutions, std::move(args.base), IsSuper,
IsDirectAccessorUse, std::move(args.subscripts), SubstFieldType);
}
switch (cast<FuncDecl>(addressor.getDecl())->getAddressorKind()) {
case AddressorKind::NotAddressor:
llvm_unreachable("not an addressor!");
// For unsafe addressors, we have no owner pointer to manage.
case AddressorKind::Unsafe:
assert(!result.second);
return result.first;
// For owning addressors, we can just let the owner get released
// at an appropriate point.
case AddressorKind::Owning:
case AddressorKind::NativeOwning:
return result.first;
// For pinning addressors, we have to push a writeback.
case AddressorKind::NativePinning: {
std::unique_ptr<LogicalPathComponent>
component(new UnpinPseudoComponent(getTypeData()));
pushWriteback(SGF, loc, std::move(component), result.second,
MaterializedLValue());
return result.first;
}
}
llvm_unreachable("bad addressor kind");
}
void print(raw_ostream &OS) const override {
printBase(OS, "AddressorComponent");
}
};
} // end anonymous namespace
RValue
TranslationPathComponent::get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && {
// Load the original value.
RValue baseVal(SGF, loc, getSubstFormalType(),
SGF.emitLoad(loc, base.getValue(),
SGF.getTypeLowering(base.getType()),
SGFContext(), IsNotTake));
// Map the base value to its substituted representation.
return std::move(*this).translate(SGF, loc, std::move(baseVal), c);
}
void TranslationPathComponent::set(SILGenFunction &SGF, SILLocation loc,
RValue &&value, ManagedValue base) && {
// Map the value to the original pattern.
RValue newValue = std::move(*this).untranslate(SGF, loc, std::move(value));
// Store to the base.
std::move(newValue).assignInto(SGF, loc, base.getValue());
}
namespace {
/// Remap an lvalue referencing a generic type to an lvalue of its
/// substituted type in a concrete context.
class OrigToSubstComponent : public TranslationPathComponent {
AbstractionPattern OrigType;
public:
OrigToSubstComponent(AbstractionPattern origType,
CanType substFormalType,
SILType loweredSubstType)
: TranslationPathComponent({ AbstractionPattern(substFormalType),
substFormalType, loweredSubstType },
OrigToSubstKind),
OrigType(origType)
{}
RValue untranslate(SILGenFunction &SGF, SILLocation loc,
RValue &&rv, SGFContext c) && override {
return SGF.emitSubstToOrigValue(loc, std::move(rv), OrigType,
getSubstFormalType(), c);
}
RValue translate(SILGenFunction &SGF, SILLocation loc,
RValue &&rv, SGFContext c) && override {
return SGF.emitOrigToSubstValue(loc, std::move(rv), OrigType,
getSubstFormalType(), c);
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
LogicalPathComponent *clone
= new OrigToSubstComponent(OrigType, getSubstFormalType(),
getTypeOfRValue());
return std::unique_ptr<LogicalPathComponent>(clone);
}
void print(raw_ostream &OS) const override {
OS << "OrigToSubstComponent("
<< getOrigFormalType() << ", "
<< getSubstFormalType() << ", "
<< getTypeOfRValue() << ")\n";
}
};
/// Remap an lvalue referencing a concrete type to an lvalue of a
/// generically-reabstracted type.
class SubstToOrigComponent : public TranslationPathComponent {
public:
SubstToOrigComponent(AbstractionPattern origType,
CanType substFormalType,
SILType loweredSubstType)
: TranslationPathComponent({ origType, substFormalType, loweredSubstType },
SubstToOrigKind)
{}
RValue untranslate(SILGenFunction &SGF, SILLocation loc,
RValue &&rv, SGFContext c) && override {
return SGF.emitOrigToSubstValue(loc, std::move(rv), getOrigFormalType(),
getSubstFormalType(), c);
}
RValue translate(SILGenFunction &SGF, SILLocation loc,
RValue &&rv, SGFContext c) && override {
return SGF.emitSubstToOrigValue(loc, std::move(rv), getOrigFormalType(),
getSubstFormalType(), c);
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
LogicalPathComponent *clone
= new SubstToOrigComponent(getOrigFormalType(), getSubstFormalType(),
getTypeOfRValue());
return std::unique_ptr<LogicalPathComponent>(clone);
}
void print(raw_ostream &OS) const override {
OS << "SubstToOrigComponent("
<< getOrigFormalType() << ", "
<< getSubstFormalType() << ", "
<< getTypeOfRValue() << ")\n";
}
};
/// Remap a weak value to Optional<T>*, or unowned pointer to T*.
class OwnershipComponent : public LogicalPathComponent {
public:
OwnershipComponent(LValueTypeData typeData)
: LogicalPathComponent(typeData, OwnershipKind) {
}
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
// Always use the same access kind for the base.
return kind;
}
void diagnoseWritebackConflict(LogicalPathComponent *RHS,
SILLocation loc1, SILLocation loc2,
SILGenFunction &SGF) override {
// no useful writeback diagnostics at this point
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && override {
assert(base && "ownership component must not be root of lvalue path");
auto &TL = SGF.getTypeLowering(getTypeOfRValue());
// Load the original value.
ManagedValue result = SGF.emitLoad(loc, base.getValue(), TL,
SGFContext(), IsNotTake);
return RValue(SGF, loc, getSubstFormalType(), result);
}
void set(SILGenFunction &SGF, SILLocation loc,
RValue &&value, ManagedValue base) && override {
assert(base && "ownership component must not be root of lvalue path");
auto &TL = SGF.getTypeLowering(base.getType());
SGF.emitSemanticStore(loc,
std::move(value).forwardAsSingleValue(SGF, loc),
base.getValue(), TL, IsNotInitialization);
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
LogicalPathComponent *clone = new OwnershipComponent(getTypeData());
return std::unique_ptr<LogicalPathComponent>(clone);
}
void print(raw_ostream &OS) const override {
OS << "OwnershipComponent(...)\n";
}
};
} // end anonymous namespace
LValue LValue::forValue(ManagedValue value,
CanType substFormalType) {
assert(value.getType().isObject());
LValueTypeData typeData = getValueTypeData(substFormalType,
value.getValue());
LValue lv;
lv.add<ValueComponent>(value, typeData, /*isRValue=*/true);
return lv;
}
LValue LValue::forAddress(ManagedValue address,
AbstractionPattern origFormalType,
CanType substFormalType) {
assert(address.isLValue());
LValueTypeData typeData = {
origFormalType, substFormalType, address.getType().getObjectType()
};
LValue lv;
lv.add<ValueComponent>(address, typeData);
return lv;
}
void LValue::addMemberComponent(SILGenFunction &SGF, SILLocation loc,
AbstractStorageDecl *storage,
SubstitutionList subs,
bool isSuper,
AccessKind accessKind,
AccessSemantics accessSemantics,
AccessStrategy accessStrategy,
CanType formalRValueType,
RValue &&indices) {
if (auto var = dyn_cast<VarDecl>(storage)) {
assert(!indices);
addMemberVarComponent(SGF, loc, var, subs, isSuper,
accessKind, accessSemantics, accessStrategy,
formalRValueType);
} else {
auto subscript = cast<SubscriptDecl>(storage);
addMemberSubscriptComponent(SGF, loc, subscript, subs, isSuper,
accessKind, accessSemantics, accessStrategy,
formalRValueType, std::move(indices));
}
}
void LValue::addOrigToSubstComponent(SILType loweredSubstType) {
loweredSubstType = loweredSubstType.getObjectType();
assert(getTypeOfRValue() != loweredSubstType &&
"reabstraction component is unnecessary!");
// Peephole away complementary reabstractions.
assert(!Path.empty() && "adding translation component to empty l-value");
if (Path.back()->getKind() == PathComponent::SubstToOrigKind) {
// But only if the lowered type matches exactly.
if (Path[Path.size()-2]->getTypeOfRValue() == loweredSubstType) {
Path.pop_back();
return;
}
// TODO: combine reabstractions; this doesn't matter all that much
// for most things, but it can be dramatically better for function
// reabstraction.
}
add<OrigToSubstComponent>(getOrigFormalType(), getSubstFormalType(),
loweredSubstType);
}
void LValue::addSubstToOrigComponent(AbstractionPattern origType,
SILType loweredSubstType) {
loweredSubstType = loweredSubstType.getObjectType();
assert(getTypeOfRValue() != loweredSubstType &&
"reabstraction component is unnecessary!");
// Peephole away complementary reabstractions.
assert(!Path.empty() && "adding translation component to empty l-value");
if (Path.back()->getKind() == PathComponent::OrigToSubstKind) {
// But only if the lowered type matches exactly.
if (Path[Path.size()-2]->getTypeOfRValue() == loweredSubstType) {
Path.pop_back();
return;
}
// TODO: combine reabstractions; this doesn't matter all that much
// for most things, but it can be dramatically better for function
// reabstraction.
}
add<SubstToOrigComponent>(origType, getSubstFormalType(), loweredSubstType);
}
void LValue::dump() const {
print(llvm::errs());
}
void LValue::print(raw_ostream &OS) const {
for (const auto &component : *this) {
component->print(OS);
}
}
LValue SILGenFunction::emitLValue(Expr *e, AccessKind accessKind) {
// Some lvalue nodes (namely BindOptionalExprs) require immediate evaluation
// of their subexpression, so we must have a writeback scope open while
// building an lvalue.
assert(InWritebackScope && "must be in a writeback scope");
LValue r = SILGenLValue(*this).visit(e, accessKind);
// If the final component has an abstraction change, introduce a
// reabstraction component.
auto substFormalType = r.getSubstFormalType();
auto loweredSubstType = getLoweredType(substFormalType);
if (r.getTypeOfRValue() != loweredSubstType.getObjectType()) {
// Logical components always re-abstract back to the substituted
// type.
assert(r.isLastComponentPhysical());
r.addOrigToSubstComponent(loweredSubstType);
}
return r;
}
LValue SILGenLValue::visitRec(Expr *e, AccessKind accessKind) {
// Non-lvalue types (references, values, metatypes, etc) form the root of a
// logical l-value.
if (!e->getType()->is<LValueType>() && !e->getType()->is<InOutType>()) {
// Decide if we can evaluate this expression at +0 for the rest of the
// lvalue.
SGFContext Ctx;
ManagedValue rv;
// Calls through opaque protocols can be done with +0 rvalues. This allows
// us to avoid materializing copies of existentials.
if (SGF.SGM.Types.isIndirectPlusZeroSelfParameter(e->getType()))
Ctx = SGFContext::AllowGuaranteedPlusZero;
else if (auto *DRE = dyn_cast<DeclRefExpr>(e)) {
// Any reference to "self" can be done at +0 so long as it is a direct
// access, since we know it is guaranteed.
// TODO: it would be great to factor this even lower into SILGen to the
// point where we can see that the parameter is +0 guaranteed. Note that
// this handles the case in initializers where there is actually a stack
// allocation for it as well.
if (isa<ParamDecl>(DRE->getDecl()) &&
DRE->getDecl()->getName() == SGF.getASTContext().Id_self &&
DRE->getDecl()->isImplicit()) {
Ctx = SGFContext::AllowGuaranteedPlusZero;
if (SGF.SelfInitDelegationState != SILGenFunction::NormalSelf) {
// This needs to be inlined since there is a Formal EvaluatioN Scope
// in emitRValueForDecl that causing any borrow for this LValue to be
// popped too soon.
auto *vd = cast<ParamDecl>(DRE->getDecl());
ManagedValue selfLValue = SGF.emitLValueForDecl(
DRE, vd, DRE->getType()->getCanonicalType(), AccessKind::Read,
DRE->getAccessSemantics());
rv = SGF.emitRValueForSelfInDelegationInit(
e, DRE->getType()->getCanonicalType(),
selfLValue.getLValueAddress(), Ctx)
.getScalarValue();
}
} else if (auto *VD = dyn_cast<VarDecl>(DRE->getDecl())) {
// All let values are guaranteed to be held alive across their lifetime,
// and won't change once initialized. Any loaded value is good for the
// duration of this expression evaluation.
if (VD->isLet())
Ctx = SGFContext::AllowGuaranteedPlusZero;
}
}
if (!rv)
rv = SGF.emitRValueAsSingleValue(e, Ctx);
CanType formalType = getSubstFormalRValueType(e);
auto typeData = getValueTypeData(formalType, rv.getValue());
LValue lv;
lv.add<ValueComponent>(rv, typeData, /*isRValue=*/true);
return lv;
}
return visit(e, accessKind);
}
LValue SILGenLValue::visitExpr(Expr *e, AccessKind accessKind) {
e->dump(llvm::errs());
llvm_unreachable("unimplemented lvalue expr");
}
SubstitutionList
SILGenModule::getNonMemberVarDeclSubstitutions(VarDecl *var) {
SubstitutionList substitutions;
auto *dc = var->getDeclContext();
if (auto *genericEnv = dc->getGenericEnvironmentOfContext())
substitutions = genericEnv->getForwardingSubstitutions();
return substitutions;
}
// For now, we don't need either an AccessKind or an
// AccessSemantics, because addressors are always directly
// dispatched.
static void
addNonMemberVarDeclAddressorComponent(SILGenModule &SGM, VarDecl *var,
CanType formalRValueType,
LValue &lvalue) {
assert(!lvalue.isValid());
auto typeData = getPhysicalStorageTypeData(SGM, var, formalRValueType);
SILType storageType = SGM.Types.getLoweredType(var->getType()).getAddressType();
lvalue.add<AddressorComponent>(var, /*isSuper=*/ false, /*direct*/ true,
SGM.getNonMemberVarDeclSubstitutions(var),
CanType(), typeData, storageType);
}
LValue
SILGenFunction::emitLValueForAddressedNonMemberVarDecl(SILLocation loc,
VarDecl *var,
CanType formalRValueType,
AccessKind accessKind,
AccessSemantics semantics) {
LValue lv;
addNonMemberVarDeclAddressorComponent(SGM, var, formalRValueType, lv);
return lv;
}
static LValue emitLValueForNonMemberVarDecl(SILGenFunction &SGF,
SILLocation loc, VarDecl *var,
CanType formalRValueType,
AccessKind accessKind,
AccessSemantics semantics) {
LValue lv;
switch (var->getAccessStrategy(semantics, accessKind)) {
case AccessStrategy::DispatchToAccessor:
llvm_unreachable("can't polymorphically access non-member variable");
// If it's a computed variable, push a reference to the getter and setter.
case AccessStrategy::DirectToAccessor: {
auto typeData = getLogicalStorageTypeData(SGF.SGM, formalRValueType);
lv.add<GetterSetterComponent>(var, /*isSuper=*/false, /*direct*/ true,
SGF.SGM.getNonMemberVarDeclSubstitutions(var),
CanType(), typeData);
break;
}
case AccessStrategy::Addressor: {
addNonMemberVarDeclAddressorComponent(SGF.SGM, var, formalRValueType, lv);
break;
}
case AccessStrategy::Storage: {
// If it's a physical value (e.g. a local variable in memory), push its
// address.
auto address = SGF.emitLValueForDecl(loc, var, formalRValueType,
accessKind, semantics);
assert(address.isLValue() &&
"physical lvalue decl ref must evaluate to an address");
auto typeData = getPhysicalStorageTypeData(SGF.SGM, var, formalRValueType);
lv.add<ValueComponent>(address, typeData);
if (address.getType().is<ReferenceStorageType>())
lv.add<OwnershipComponent>(typeData);
break;
}
case AccessStrategy::BehaviorStorage:
// TODO: Behaviors aren't supported for non-instance properties yet.
llvm_unreachable("not implemented");
}
return lv;
}
LValue SILGenLValue::visitDiscardAssignmentExpr(DiscardAssignmentExpr *e,
AccessKind accessKind) {
LValueTypeData typeData = getValueTypeData(SGF, e);
SILValue address = SGF.emitTemporaryAllocation(e, typeData.TypeOfRValue);
address = SGF.B.createMarkUninitialized(e, address,
MarkUninitializedInst::Var);
LValue lv;
lv.add<ValueComponent>(SGF.emitManagedBufferWithCleanup(address), typeData);
return lv;
}
LValue SILGenLValue::visitDeclRefExpr(DeclRefExpr *e, AccessKind accessKind) {
// The only non-member decl that can be an lvalue is VarDecl.
return emitLValueForNonMemberVarDecl(SGF, e, cast<VarDecl>(e->getDecl()),
getSubstFormalRValueType(e),
accessKind,
e->getAccessSemantics());
}
LValue SILGenLValue::visitOpaqueValueExpr(OpaqueValueExpr *e,
AccessKind accessKind) {
// Handle an opaque lvalue that refers to an opened existential.
auto known = openedExistentials.find(e);
if (known != openedExistentials.end()) {
// Dig the open-existential expression out of the list.
OpenExistentialExpr *opened = known->second;
openedExistentials.erase(known);
// Do formal evaluation of the underlying existential lvalue.
LValue existentialLV = visitRec(opened->getExistentialValue(), accessKind);
ManagedValue existentialAddr
= SGF.emitAddressOfLValue(e, std::move(existentialLV), accessKind);
// Open up the existential.
LValue lv;
lv.add<ValueComponent>(existentialAddr, existentialLV.getTypeData());
lv.add<OpenOpaqueExistentialComponent>(
cast<ArchetypeType>(opened->getOpenedArchetype()->getCanonicalType()));
return lv;
}
assert(SGF.OpaqueValues.count(e) && "Didn't bind OpaqueValueExpr");
auto &entry = SGF.OpaqueValues.find(e)->second;
assert(!entry.HasBeenConsumed && "opaque value already consumed");
entry.HasBeenConsumed = true;
RegularLocation loc(e);
LValue lv;
lv.add<ValueComponent>(entry.Value.borrow(SGF, loc),
getValueTypeData(SGF, e));
return lv;
}
LValue SILGenLValue::visitDotSyntaxBaseIgnoredExpr(DotSyntaxBaseIgnoredExpr *e,
AccessKind accessKind) {
SGF.emitIgnoredExpr(e->getLHS());
return visitRec(e->getRHS(), accessKind);
}
static AccessKind getBaseAccessKindForAccessor(FuncDecl *accessor) {
if (accessor->isMutating()) {
return AccessKind::ReadWrite;
} else {
return AccessKind::Read;
}
}
/// Return the appropriate access kind for the base l-value of a
/// particular member, which is being accessed in a particular way.
static AccessKind getBaseAccessKind(AbstractStorageDecl *member,
AccessKind accessKind,
AccessStrategy strategy) {
switch (strategy) {
// Assume that the member only partially projects the enclosing value.
case AccessStrategy::Storage:
return (accessKind == AccessKind::Read
? AccessKind::Read : AccessKind::ReadWrite);
case AccessStrategy::Addressor:
return getBaseAccessKindForAccessor(
member->getAddressorForAccess(accessKind));
case AccessStrategy::DirectToAccessor:
case AccessStrategy::DispatchToAccessor:
if (accessKind == AccessKind::Read) {
return getBaseAccessKindForAccessor(member->getGetter());
} else {
return getBaseAccessKindForAccessor(member->getSetter());
}
case AccessStrategy::BehaviorStorage:
// We should only access the behavior storage for initialization purposes.
assert(accessKind == AccessKind::Write);
return AccessKind::Write;
}
llvm_unreachable("bad access strategy");
}
LValue SILGenLValue::visitMemberRefExpr(MemberRefExpr *e,
AccessKind accessKind) {
// MemberRefExpr can refer to type and function members, but the only case
// that can be an lvalue is a VarDecl.
VarDecl *var = cast<VarDecl>(e->getMember().getDecl());
AccessStrategy strategy =
var->getAccessStrategy(e->getAccessSemantics(), accessKind);
LValue lv = visitRec(e->getBase(),
getBaseAccessKind(var, accessKind, strategy));
assert(lv.isValid());
CanType substFormalRValueType = getSubstFormalRValueType(e);
lv.addMemberVarComponent(SGF, e, var, e->getMember().getSubstitutions(),
e->isSuper(), accessKind, e->getAccessSemantics(),
strategy, substFormalRValueType);
return lv;
}
void LValue::addMemberVarComponent(SILGenFunction &SGF, SILLocation loc,
VarDecl *var,
SubstitutionList subs,
bool isSuper,
AccessKind accessKind,
AccessSemantics accessSemantics,
AccessStrategy strategy,
CanType formalRValueType) {
CanType baseFormalType = getSubstFormalType();
// Use the property accessors if the variable has accessors and this isn't a
// direct access to underlying storage.
if (strategy == AccessStrategy::DirectToAccessor ||
strategy == AccessStrategy::DispatchToAccessor) {
auto typeData = getLogicalStorageTypeData(SGF.SGM, formalRValueType);
add<GetterSetterComponent>(var, isSuper,
strategy == AccessStrategy::DirectToAccessor,
subs, baseFormalType, typeData);
return;
}
assert(strategy == AccessStrategy::Addressor ||
strategy == AccessStrategy::Storage ||
strategy == AccessStrategy::BehaviorStorage);
// Otherwise, the lvalue access is performed with a fragile element reference.
// Find the substituted storage type.
SILType varStorageType =
SGF.SGM.Types.getSubstitutedStorageType(var, formalRValueType);
// For static variables, emit a reference to the global variable backing
// them.
// FIXME: This has to be dynamically looked up for classes, and
// dynamically instantiated for generics.
if (strategy == AccessStrategy::Storage && var->isStatic()) {
// FIXME: this implicitly drops the earlier components, but maybe
// we ought to evaluate them for side-effects even during the
// formal access?
*this = emitLValueForNonMemberVarDecl(SGF, loc, var,
formalRValueType,
accessKind, accessSemantics);
return;
}
auto typeData = getPhysicalStorageTypeData(SGF.SGM, var, formalRValueType);
// For behavior initializations, we should have set up a marking proxy that
// replaces the access path.
if (strategy == AccessStrategy::BehaviorStorage) {
auto addr = SGF.VarLocs.find(var);
assert(addr != SGF.VarLocs.end() && addr->second.value);
Path.clear();
add<ValueComponent>(ManagedValue::forUnmanaged(addr->second.value),
typeData);
// For member variables, this access is done w.r.t. a base computation that
// was already emitted. This member is accessed off of it.
} else if (strategy == AccessStrategy::Addressor) {
add<AddressorComponent>(var, isSuper, /*direct*/ true, subs,
baseFormalType, typeData, varStorageType);
} else if (baseFormalType->mayHaveSuperclass()) {
add<RefElementComponent>(var, varStorageType, typeData);
} else {
assert(baseFormalType->getStructOrBoundGenericStruct());
add<StructElementComponent>(var, varStorageType, typeData);
}
// If the member has weak or unowned storage, convert it away.
if (varStorageType.is<ReferenceStorageType>()) {
add<OwnershipComponent>(typeData);
}
}
LValue SILGenLValue::visitSubscriptExpr(SubscriptExpr *e,
AccessKind accessKind) {
auto decl = cast<SubscriptDecl>(e->getDecl().getDecl());
auto accessSemantics = e->getAccessSemantics();
auto strategy = decl->getAccessStrategy(accessSemantics, accessKind);
LValue lv = visitRec(e->getBase(),
getBaseAccessKind(decl, accessKind, strategy));
assert(lv.isValid());
Expr *indexExpr = e->getIndex();
// FIXME: This admits varargs tuples, which should only be handled as part of
// argument emission.
RValue index = SGF.emitRValue(indexExpr);
CanType formalRValueType = getSubstFormalRValueType(e);
lv.addMemberSubscriptComponent(SGF, e, decl, e->getDecl().getSubstitutions(),
e->isSuper(), accessKind, accessSemantics,
strategy, formalRValueType, std::move(index),
indexExpr);
return lv;
}
void LValue::addMemberSubscriptComponent(SILGenFunction &SGF, SILLocation loc,
SubscriptDecl *decl,
SubstitutionList subs,
bool isSuper,
AccessKind accessKind,
AccessSemantics accessSemantics,
AccessStrategy strategy,
CanType formalRValueType,
RValue &&indices,
Expr *indexExprForDiagnostics) {
CanType baseFormalType = getSubstFormalType();
if (strategy == AccessStrategy::DirectToAccessor ||
strategy == AccessStrategy::DispatchToAccessor) {
auto typeData = getLogicalStorageTypeData(SGF.SGM, formalRValueType);
add<GetterSetterComponent>(decl, isSuper,
strategy == AccessStrategy::DirectToAccessor,
subs, baseFormalType, typeData,
indexExprForDiagnostics, &indices);
} else {
assert(strategy == AccessStrategy::Addressor);
auto typeData = getPhysicalStorageTypeData(SGF.SGM, decl, formalRValueType);
auto storageType =
SGF.SGM.Types.getSubstitutedStorageType(decl, formalRValueType);
add<AddressorComponent>(decl, isSuper, /*direct*/ true,
subs, baseFormalType, typeData, storageType,
indexExprForDiagnostics, &indices);
}
}
LValue SILGenLValue::visitTupleElementExpr(TupleElementExpr *e,
AccessKind accessKind) {
unsigned index = e->getFieldNumber();
LValue lv = visitRec(e->getBase(),
accessKind == AccessKind::Read
? AccessKind::Read : AccessKind::ReadWrite);
auto baseTypeData = lv.getTypeData();
LValueTypeData typeData = {
baseTypeData.OrigFormalType.getTupleElementType(index),
cast<TupleType>(baseTypeData.SubstFormalType).getElementType(index),
baseTypeData.TypeOfRValue.getTupleElementType(index)
};
lv.add<TupleElementComponent>(index, typeData);
return lv;
}
LValue SILGenLValue::visitOpenExistentialExpr(OpenExistentialExpr *e,
AccessKind accessKind) {
// If the opaque value is not an lvalue, open the existential immediately.
if (!e->getOpaqueValue()->getType()->is<LValueType>()) {
return SGF.emitOpenExistentialExpr<LValue>(e,
[&](Expr *subExpr) -> LValue {
return visitRec(subExpr,
accessKind);
});
}
// Record the fact that we're opening this existential. The actual
// opening operation will occur when we see the OpaqueValueExpr.
bool inserted = openedExistentials.insert({e->getOpaqueValue(), e}).second;
(void)inserted;
assert(inserted && "already have this opened existential?");
// Visit the subexpression.
LValue lv = visitRec(e->getSubExpr(), accessKind);
// Sanity check that we did see the OpaqueValueExpr.
assert(openedExistentials.count(e->getOpaqueValue()) == 0 &&
"opened existential not removed?");
return lv;
}
static LValueTypeData
getOptionalObjectTypeData(SILGenFunction &SGF,
const LValueTypeData &baseTypeData) {
EnumElementDecl *someDecl = SGF.getASTContext().getOptionalSomeDecl();
return {
baseTypeData.OrigFormalType.getAnyOptionalObjectType(),
baseTypeData.SubstFormalType.getAnyOptionalObjectType(),
baseTypeData.TypeOfRValue.getEnumElementType(someDecl, SGF.SGM.M),
};
}
LValue SILGenLValue::visitForceValueExpr(ForceValueExpr *e,
AccessKind accessKind) {
LValue lv = visitRec(e->getSubExpr(), accessKind);
LValueTypeData typeData = getOptionalObjectTypeData(SGF, lv.getTypeData());
lv.add<ForceOptionalObjectComponent>(typeData);
return lv;
}
LValue SILGenLValue::visitBindOptionalExpr(BindOptionalExpr *e,
AccessKind accessKind) {
// Do formal evaluation of the base l-value.
LValue optLV = visitRec(e->getSubExpr(), accessKind);
LValueTypeData optTypeData = optLV.getTypeData();
LValueTypeData valueTypeData = getOptionalObjectTypeData(SGF, optTypeData);
// The chaining operator immediately begins a formal access to the
// base l-value. In concrete terms, this means we can immediately
// evaluate the base down to an address.
ManagedValue optAddr =
SGF.emitAddressOfLValue(e, std::move(optLV), accessKind);
// Bind the value, branching to the destination address if there's no
// value there.
SGF.emitBindOptional(e, optAddr, e->getDepth());
// Project out the payload on the success branch. We can just use a
// naked ValueComponent here; this is effectively a separate l-value.
ManagedValue valueAddr =
getAddressOfOptionalValue(SGF, e, optAddr, valueTypeData);
LValue valueLV;
valueLV.add<ValueComponent>(valueAddr, valueTypeData);
return valueLV;
}
LValue SILGenLValue::visitInOutExpr(InOutExpr *e, AccessKind accessKind) {
return visitRec(e->getSubExpr(), accessKind);
}
/// Emit an lvalue that refers to the given property. This is
/// designed to work with ManagedValue 'base's that are either +0 or +1.
LValue SILGenFunction::emitPropertyLValue(SILLocation loc, ManagedValue base,
CanType baseFormalType,
VarDecl *ivar, AccessKind accessKind,
AccessSemantics semantics) {
SILGenLValue sgl(*this);
LValue lv;
auto baseType = base.getType().getSwiftRValueType();
auto subMap = baseType->getContextSubstitutionMap(
SGM.M.getSwiftModule(), ivar->getDeclContext());
SmallVector<Substitution, 4> subs;
if (auto *genericSig = ivar->getDeclContext()->getGenericSignatureOfContext())
genericSig->getSubstitutions(subMap, subs);
LValueTypeData baseTypeData = getValueTypeData(baseFormalType,
base.getValue());
// Refer to 'self' as the base of the lvalue.
lv.add<ValueComponent>(base, baseTypeData, /*isRValue=*/!base.isLValue());
auto substFormalType = ivar->getInterfaceType().subst(subMap)
->getCanonicalType();
AccessStrategy strategy =
ivar->getAccessStrategy(semantics, accessKind);
// Use the property accessors if the variable has accessors and this
// isn't a direct access to underlying storage.
if (strategy == AccessStrategy::DirectToAccessor ||
strategy == AccessStrategy::DispatchToAccessor) {
auto typeData = getLogicalStorageTypeData(SGM, substFormalType);
lv.add<GetterSetterComponent>(ivar, /*super*/ false,
strategy == AccessStrategy::DirectToAccessor,
subs, baseFormalType, typeData);
return lv;
}
assert(strategy == AccessStrategy::Addressor ||
strategy == AccessStrategy::Storage);
// Find the substituted storage type.
SILType varStorageType =
SGM.Types.getSubstitutedStorageType(ivar, substFormalType);
auto typeData = getPhysicalStorageTypeData(SGM, ivar, substFormalType);
if (strategy == AccessStrategy::Addressor) {
lv.add<AddressorComponent>(ivar, /*super*/ false, /*direct*/ true,
subs, baseFormalType, typeData, varStorageType);
} else if (baseFormalType->hasReferenceSemantics()) {
lv.add<RefElementComponent>(ivar, varStorageType, typeData);
} else {
lv.add<StructElementComponent>(ivar, varStorageType, typeData);
}
if (varStorageType.is<ReferenceStorageType>()) {
auto formalRValueType =
ivar->getDeclContext()->mapTypeIntoContext(ivar->getInterfaceType())
->getReferenceStorageReferent()
->getCanonicalType();
auto typeData =
getPhysicalStorageTypeData(SGM, ivar, formalRValueType);
lv.add<OwnershipComponent>(typeData);
}
return lv;
}
/// Load an r-value out of the given address.
///
/// \param rvalueTL - the type lowering for the type-of-rvalue
/// of the address
/// \param isGuaranteedValid - true if the value in this address
/// is guaranteed to be valid for the duration of the current
/// evaluation (see SGFContext::AllowGuaranteedPlusZero)
ManagedValue SILGenFunction::emitLoad(SILLocation loc, SILValue addr,
const TypeLowering &rvalueTL,
SGFContext C, IsTake_t isTake,
bool isGuaranteedValid) {
// Get the lowering for the address type. We can avoid a re-lookup
// in the very common case of this being equivalent to the r-value
// type.
auto &addrTL =
(addr->getType() == rvalueTL.getLoweredType().getAddressType()
? rvalueTL : getTypeLowering(addr->getType()));
// Never do a +0 load together with a take.
bool isPlusZeroOk = (isTake == IsNotTake &&
(isGuaranteedValid ? C.isGuaranteedPlusZeroOk()
: C.isImmediatePlusZeroOk()));
if (rvalueTL.isAddressOnly() && silConv.useLoweredAddresses()) {
// If the client is cool with a +0 rvalue, the decl has an address-only
// type, and there are no conversions, then we can return this as a +0
// address RValue.
if (isPlusZeroOk && rvalueTL.getLoweredType() == addrTL.getLoweredType())
return ManagedValue::forUnmanaged(addr);
// Copy the address-only value.
return B.bufferForExpr(
loc, rvalueTL.getLoweredType(), rvalueTL, C,
[&](SILValue newAddr) {
emitSemanticLoadInto(loc, addr, addrTL, newAddr, rvalueTL,
isTake, IsInitialization);
});
}
// Ok, this is something loadable. If this is a non-take access at plus zero,
// we can perform a +0 load of the address instead of materializing a +1
// value.
if (isPlusZeroOk && addrTL.getLoweredType() == rvalueTL.getLoweredType()) {
return B.createLoadBorrow(loc, ManagedValue::forUnmanaged(addr));
}
// Load the loadable value, and retain it if we aren't taking it.
SILValue loadedV = emitSemanticLoad(loc, addr, addrTL, rvalueTL, isTake);
return emitManagedRValueWithCleanup(loadedV);
}
/// Load an r-value out of the given address.
///
/// \param rvalueTL - the type lowering for the type-of-rvalue
/// of the address
/// \param isGuaranteedValid - true if the value in this address
/// is guaranteed to be valid for the duration of the current
/// evaluation (see SGFContext::AllowGuaranteedPlusZero)
ManagedValue SILGenFunction::emitFormalAccessLoad(SILLocation loc,
SILValue addr,
const TypeLowering &rvalueTL,
SGFContext C, IsTake_t isTake,
bool isGuaranteedValid) {
// Get the lowering for the address type. We can avoid a re-lookup
// in the very common case of this being equivalent to the r-value
// type.
auto &addrTL = (addr->getType() == rvalueTL.getLoweredType().getAddressType()
? rvalueTL
: getTypeLowering(addr->getType()));
// Never do a +0 load together with a take.
bool isPlusZeroOk =
(isTake == IsNotTake && (isGuaranteedValid ? C.isGuaranteedPlusZeroOk()
: C.isImmediatePlusZeroOk()));
if (rvalueTL.isAddressOnly() && silConv.useLoweredAddresses()) {
// If the client is cool with a +0 rvalue, the decl has an address-only
// type, and there are no conversions, then we can return this as a +0
// address RValue.
if (isPlusZeroOk && rvalueTL.getLoweredType() == addrTL.getLoweredType())
return ManagedValue::forUnmanaged(addr);
// Copy the address-only value.
return B.formalAccessBufferForExpr(
loc, rvalueTL.getLoweredType(), rvalueTL, C,
[&](SILValue addressForCopy) {
emitSemanticLoadInto(loc, addr, addrTL, addressForCopy, rvalueTL,
isTake, IsInitialization);
});
}
// Ok, this is something loadable. If this is a non-take access at plus zero,
// we can perform a +0 load of the address instead of materializing a +1
// value.
if (isPlusZeroOk && addrTL.getLoweredType() == rvalueTL.getLoweredType()) {
return B.createFormalAccessLoadBorrow(loc,
ManagedValue::forUnmanaged(addr));
}
// Load the loadable value, and retain it if we aren't taking it.
SILValue loadedV = emitSemanticLoad(loc, addr, addrTL, rvalueTL, isTake);
return emitFormalAccessManagedRValueWithCleanup(loc, loadedV);
}
static void emitUnloweredStoreOfCopy(SILGenBuilder &B, SILLocation loc,
SILValue value, SILValue addr,
IsInitialization_t isInit) {
if (isInit) {
B.emitStoreValueOperation(loc, value, addr, StoreOwnershipQualifier::Init);
} else {
B.createAssign(loc, value, addr);
}
}
SILValue SILGenFunction::emitConversionToSemanticRValue(SILLocation loc,
SILValue src,
const TypeLowering &valueTL) {
// Weak storage types are handled with their underlying type.
assert(!src->getType().is<WeakStorageType>() &&
"weak pointers are always the right optional types");
// For @unowned(safe) types, we need to generate a strong retain and
// strip the unowned box.
if (auto unownedType = src->getType().getAs<UnownedStorageType>()) {
assert(unownedType->isLoadable(ResilienceExpansion::Maximal));
(void) unownedType;
B.createStrongRetainUnowned(loc, src, B.getDefaultAtomicity());
return B.createUnownedToRef(loc, src,
SILType::getPrimitiveObjectType(unownedType.getReferentType()));
}
// For @unowned(unsafe) types, we need to strip the unmanaged box
// and then do an (unsafe) retain.
if (auto unmanagedType = src->getType().getAs<UnmanagedStorageType>()) {
auto result = B.createUnmanagedToRef(loc, src,
SILType::getPrimitiveObjectType(unmanagedType.getReferentType()));
// SEMANTIC ARC TODO: Does this need a cleanup?
return B.createCopyValue(loc, result);
}
llvm_unreachable("unexpected storage type that differs from type-of-rvalue");
}
ManagedValue SILGenFunction::emitConversionToSemanticRValue(
SILLocation loc, ManagedValue src, const TypeLowering &valueTL) {
// Weak storage types are handled with their underlying type.
assert(!src.getType().is<WeakStorageType>() &&
"weak pointers are always the right optional types");
// For @unowned(safe) types, we need to generate a strong retain and
// strip the unowned box.
if (src.getType().is<UnownedStorageType>()) {
return B.createCopyUnownedValue(loc, src);
}
// For @unowned(unsafe) types, we need to strip the unmanaged box
// and then do an (unsafe) retain.
if (src.getType().is<UnmanagedStorageType>()) {
return B.createUnsafeCopyUnownedValue(loc, src);
}
llvm_unreachable("unexpected storage type that differs from type-of-rvalue");
}
/// Given that the type-of-rvalue differs from the type-of-storage,
/// and given that the type-of-rvalue is loadable, produce a +1 scalar
/// of the type-of-rvalue.
static SILValue emitLoadOfSemanticRValue(SILGenFunction &SGF,
SILLocation loc,
SILValue src,
const TypeLowering &valueTL,
IsTake_t isTake) {
SILType storageType = src->getType();
// For @weak types, we need to create an Optional<T>.
// Optional<T> is currently loadable, but it probably won't be forever.
if (storageType.is<WeakStorageType>())
return SGF.B.createLoadWeak(loc, src, isTake);
// For @unowned(safe) types, we need to strip the unowned box.
if (auto unownedType = storageType.getAs<UnownedStorageType>()) {
if (!unownedType->isLoadable(ResilienceExpansion::Maximal)) {
return SGF.B.createLoadUnowned(loc, src, isTake);
}
auto unownedValue =
SGF.B.emitLoadValueOperation(loc, src, LoadOwnershipQualifier::Take);
SGF.B.createStrongRetainUnowned(loc, unownedValue, SGF.B.getDefaultAtomicity());
if (isTake)
SGF.B.createUnownedRelease(loc, unownedValue, SGF.B.getDefaultAtomicity());
return SGF.B.createUnownedToRef(
loc, unownedValue,
SILType::getPrimitiveObjectType(unownedType.getReferentType()));
}
// For @unowned(unsafe) types, we need to strip the unmanaged box.
if (auto unmanagedType = src->getType().getAs<UnmanagedStorageType>()) {
auto value = SGF.B.createLoad(loc, src, LoadOwnershipQualifier::Trivial);
auto result = SGF.B.createUnmanagedToRef(loc, value,
SILType::getPrimitiveObjectType(unmanagedType.getReferentType()));
// SEMANTIC ARC TODO: Does this need a cleanup?
return SGF.B.createCopyValue(loc, result);
}
// NSString * must be bridged to String.
if (storageType.getSwiftRValueType() == SGF.SGM.Types.getNSStringType()) {
auto nsstr = SGF.B.createLoad(loc, src, LoadOwnershipQualifier::Copy);
auto str = SGF.emitBridgedToNativeValue(loc,
ManagedValue::forUnmanaged(nsstr),
SILFunctionTypeRepresentation::CFunctionPointer,
SGF.SGM.Types.getStringType());
return str.forward(SGF);
}
llvm_unreachable("unexpected storage type that differs from type-of-rvalue");
}
/// Given that the type-of-rvalue differs from the type-of-storage,
/// store a +1 value (possibly not a scalar) of the type-of-rvalue
/// into the given address.
static void emitStoreOfSemanticRValue(SILGenFunction &SGF,
SILLocation loc,
SILValue value,
SILValue dest,
const TypeLowering &valueTL,
IsInitialization_t isInit) {
auto storageType = dest->getType();
// For @weak types, we need to break down an Optional<T> and then
// emit the storeWeak ourselves.
if (storageType.is<WeakStorageType>()) {
SGF.B.createStoreWeak(loc, value, dest, isInit);
// store_weak doesn't take ownership of the input, so cancel it out.
SGF.B.emitDestroyValueOperation(loc, value);
return;
}
// For @unowned(safe) types, we need to enter the unowned box by
// turning the strong retain into an unowned retain.
if (auto unownedType = storageType.getAs<UnownedStorageType>()) {
// FIXME: resilience
if (!unownedType->isLoadable(ResilienceExpansion::Maximal)) {
SGF.B.createStoreUnowned(loc, value, dest, isInit);
// store_unowned doesn't take ownership of the input, so cancel it out.
SGF.B.emitDestroyValueOperation(loc, value);
return;
}
auto unownedValue =
SGF.B.createRefToUnowned(loc, value, storageType.getObjectType());
SGF.B.createUnownedRetain(loc, unownedValue, SGF.B.getDefaultAtomicity());
emitUnloweredStoreOfCopy(SGF.B, loc, unownedValue, dest, isInit);
SGF.B.emitDestroyValueOperation(loc, value);
return;
}
// For @unowned(unsafe) types, we need to enter the unmanaged box and
// release the strong retain.
if (storageType.is<UnmanagedStorageType>()) {
auto unmanagedValue =
SGF.B.createRefToUnmanaged(loc, value, storageType.getObjectType());
emitUnloweredStoreOfCopy(SGF.B, loc, unmanagedValue, dest, isInit);
SGF.B.emitDestroyValueOperation(loc, value);
return;
}
llvm_unreachable("unexpected storage type that differs from type-of-rvalue");
}
/// Load a value of the type-of-rvalue out of the given address as a
/// scalar. The type-of-rvalue must be loadable.
SILValue SILGenFunction::emitSemanticLoad(SILLocation loc,
SILValue src,
const TypeLowering &srcTL,
const TypeLowering &rvalueTL,
IsTake_t isTake) {
assert(srcTL.getLoweredType().getAddressType() == src->getType());
assert(rvalueTL.isLoadable() || !silConv.useLoweredAddresses());
// Easy case: the types match.
if (srcTL.getLoweredType() == rvalueTL.getLoweredType()) {
return srcTL.emitLoadOfCopy(B, loc, src, isTake);
}
return emitLoadOfSemanticRValue(*this, loc, src, rvalueTL, isTake);
}
/// Load a value of the type-of-reference out of the given address
/// and into the destination address.
void SILGenFunction::emitSemanticLoadInto(SILLocation loc,
SILValue src,
const TypeLowering &srcTL,
SILValue dest,
const TypeLowering &destTL,
IsTake_t isTake,
IsInitialization_t isInit) {
assert(srcTL.getLoweredType().getAddressType() == src->getType());
assert(destTL.getLoweredType().getAddressType() == dest->getType());
// Easy case: the types match.
if (srcTL.getLoweredType() == destTL.getLoweredType()) {
B.createCopyAddr(loc, src, dest, isTake, isInit);
return;
}
auto rvalue = emitLoadOfSemanticRValue(*this, loc, src, srcTL, isTake);
emitUnloweredStoreOfCopy(B, loc, rvalue, dest, isInit);
}
/// Store an r-value into the given address as an initialization.
void SILGenFunction::emitSemanticStore(SILLocation loc,
SILValue rvalue,
SILValue dest,
const TypeLowering &destTL,
IsInitialization_t isInit) {
assert(destTL.getLoweredType().getAddressType() == dest->getType());
// Easy case: the types match.
if (rvalue->getType() == destTL.getLoweredType()) {
assert(!silConv.useLoweredAddresses()
|| (destTL.isAddressOnly() == rvalue->getType().isAddress()));
if (rvalue->getType().isAddress()) {
B.createCopyAddr(loc, rvalue, dest, IsTake, isInit);
} else {
emitUnloweredStoreOfCopy(B, loc, rvalue, dest, isInit);
}
return;
}
auto &rvalueTL = getTypeLowering(rvalue->getType());
emitStoreOfSemanticRValue(*this, loc, rvalue, dest, rvalueTL, isInit);
}
/// Convert a semantic rvalue to a value of storage type.
SILValue SILGenFunction::emitConversionFromSemanticValue(SILLocation loc,
SILValue semanticValue,
SILType storageType) {
auto &destTL = getTypeLowering(storageType);
(void)destTL;
// Easy case: the types match.
if (semanticValue->getType() == storageType) {
return semanticValue;
}
// @weak types are never loadable, so we don't need to handle them here.
// For @unowned types, place into an unowned box.
if (auto unownedType = storageType.getAs<UnownedStorageType>()) {
assert(unownedType->isLoadable(ResilienceExpansion::Maximal));
(void) unownedType;
SILValue unowned = B.createRefToUnowned(loc, semanticValue, storageType);
B.createUnownedRetain(loc, unowned, B.getDefaultAtomicity());
B.emitDestroyValueOperation(loc, semanticValue);
return unowned;
}
// For @unmanaged types, place into an unmanaged box.
if (storageType.is<UnmanagedStorageType>()) {
SILValue unmanaged =
B.createRefToUnmanaged(loc, semanticValue, storageType);
B.emitDestroyValueOperation(loc, semanticValue);
return unmanaged;
}
llvm_unreachable("unexpected storage type that differs from type-of-rvalue");
}
static void emitTsanInoutAccess(SILGenFunction &SGF, SILLocation loc,
ManagedValue address) {
assert(address.getType().isAddress());
SILValue accessFnArgs[] = {address.getValue()};
SGF.B.createBuiltin(loc, SGF.getASTContext().getIdentifier("tsanInoutAccess"),
SGF.SGM.Types.getEmptyTupleType(), {}, accessFnArgs);
}
/// Produce a physical address that corresponds to the given l-value
/// component.
static ManagedValue drillIntoComponent(SILGenFunction &SGF,
SILLocation loc,
PathComponent &&component,
ManagedValue base,
AccessKind accessKind,
TSanKind tsanKind) {
ManagedValue addr;
if (component.isPhysical()) {
addr = std::move(component.asPhysical()).offset(SGF, loc, base, accessKind);
} else {
auto &lcomponent = component.asLogical();
addr = std::move(lcomponent).getMaterialized(SGF, loc, base, accessKind);
}
if (!SGF.getASTContext().LangOpts.DisableTsanInoutInstrumentation &&
SGF.getModule().getOptions().Sanitize == SanitizerKind::Thread &&
tsanKind == TSanKind::InoutAccess && !component.isRValue()) {
emitTsanInoutAccess(SGF, loc, addr);
}
return addr;
}
/// Find the last component of the given lvalue and derive a base
/// location for it.
static PathComponent &&
drillToLastComponent(SILGenFunction &SGF,
SILLocation loc,
LValue &&lv,
ManagedValue &addr,
AccessKind accessKind,
TSanKind tsanKind = TSanKind::None) {
assert(lv.begin() != lv.end() &&
"lvalue must have at least one component");
// Remember all the access kinds we needed along the path.
SmallVector<AccessKind, 8> pathAccessKinds;
for (auto i = lv.end(), e = lv.begin() + 1; i != e; --i) {
pathAccessKinds.push_back(accessKind);
accessKind = (*(i-1))->getBaseAccessKind(SGF, accessKind);
}
for (auto i = lv.begin(), e = lv.end() - 1; i != e; ++i) {
addr = drillIntoComponent(SGF, loc, std::move(**i), addr, accessKind,
tsanKind);
accessKind = pathAccessKinds.pop_back_val();
}
return std::move(**(lv.end() - 1));
}
RValue SILGenFunction::emitLoadOfLValue(SILLocation loc, LValue &&src,
SGFContext C, bool isGuaranteedValid) {
// Any writebacks should be scoped to after the load.
FormalEvaluationScope scope(*this);
ManagedValue addr;
PathComponent &&component =
drillToLastComponent(*this, loc, std::move(src), addr, AccessKind::Read);
// If the last component is physical, just drill down and load from it.
if (component.isPhysical()) {
addr = std::move(component.asPhysical())
.offset(*this, loc, addr, AccessKind::Read);
return RValue(*this, loc, src.getSubstFormalType(),
emitLoad(loc, addr.getValue(),
getTypeLowering(src.getTypeOfRValue()), C, IsNotTake,
isGuaranteedValid));
}
// If the last component is logical, just emit a get.
return std::move(component.asLogical()).get(*this, loc, addr, C);
}
ManagedValue SILGenFunction::emitAddressOfLValue(SILLocation loc,
LValue &&src,
AccessKind accessKind,
TSanKind tsanKind) {
ManagedValue addr;
PathComponent &&component =
drillToLastComponent(*this, loc, std::move(src), addr, accessKind,
tsanKind);
addr = drillIntoComponent(*this, loc, std::move(component), addr, accessKind,
tsanKind);
assert(addr.getType().isAddress() &&
"resolving lvalue did not give an address");
return ManagedValue::forLValue(addr.getValue());
}
void SILGenFunction::emitAssignToLValue(SILLocation loc, RValue &&src,
LValue &&dest) {
FormalEvaluationScope scope(*this);
// Peephole: instead of materializing and then assigning into a
// translation component, untransform the value first.
while (dest.isLastComponentTranslation()) {
src = std::move(dest.getLastTranslationComponent())
.untranslate(*this, loc, std::move(src));
dest.dropLastTranslationComponent();
}
// Resolve all components up to the last, keeping track of value-type logical
// properties we need to write back to.
ManagedValue destAddr;
PathComponent &&component =
drillToLastComponent(*this, loc, std::move(dest), destAddr,
AccessKind::ReadWrite);
// Write to the tail component.
if (component.isPhysical()) {
auto finalDestAddr =
std::move(component.asPhysical()).offset(*this, loc, destAddr,
AccessKind::Write);
std::move(src).assignInto(*this, loc, finalDestAddr.getValue());
} else {
std::move(component.asLogical()).set(*this, loc, std::move(src), destAddr);
}
// The writeback scope closing will propagate the value back up through the
// writeback chain.
}
void SILGenFunction::emitCopyLValueInto(SILLocation loc, LValue &&src,
Initialization *dest) {
auto skipPeephole = [&]{
auto loaded = emitLoadOfLValue(loc, std::move(src), SGFContext(dest));
if (!loaded.isInContext())
std::move(loaded).forwardInto(*this, loc, dest);
};
// If the source is a physical lvalue, the destination is a single address,
// and there's no semantic conversion necessary, do a copy_addr from the
// lvalue into the destination.
if (!src.isPhysical())
return skipPeephole();
auto destAddr = dest->getAddressOrNull();
if (!destAddr)
return skipPeephole();
if (src.getTypeOfRValue().getSwiftRValueType()
!= destAddr->getType().getSwiftRValueType())
return skipPeephole();
auto srcAddr = emitAddressOfLValue(loc, std::move(src), AccessKind::Read)
.getUnmanagedValue();
B.createCopyAddr(loc, srcAddr, destAddr, IsNotTake, IsInitialization);
dest->finishInitialization(*this);
}
void SILGenFunction::emitAssignLValueToLValue(SILLocation loc,
LValue &&src,
LValue &&dest) {
// Only perform the peephole if both operands are physical and there's no
// semantic conversion necessary.
if (!src.isPhysical() || !dest.isPhysical()) {
RValue loaded = emitLoadOfLValue(loc, std::move(src), SGFContext());
emitAssignToLValue(loc, std::move(loaded), std::move(dest));
return;
}
auto srcAddr = emitAddressOfLValue(loc, std::move(src), AccessKind::Read)
.getUnmanagedValue();
auto destAddr = emitAddressOfLValue(loc, std::move(dest), AccessKind::Write)
.getUnmanagedValue();
if (srcAddr->getType() == destAddr->getType()) {
B.createCopyAddr(loc, srcAddr, destAddr, IsNotTake, IsNotInitialization);
} else {
// If there's a semantic conversion necessary, do a load then assign.
auto loaded = emitLoad(loc, srcAddr, getTypeLowering(src.getTypeOfRValue()),
SGFContext(),
IsNotTake);
loaded.assignInto(*this, loc, destAddr);
}
}