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fuchsia / third_party / swift / 039db9ab3204c148bb14d626169ed20ab6ba84e0 / . / lib / SILGen / SILGenLValue.cpp
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//===--- 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 "ASTVisitor.h"
#include "ArgumentScope.h"
#include "ArgumentSource.h"
#include "Conversion.h"
#include "Initialization.h"
#include "LValue.h"
#include "RValue.h"
#include "SILGen.h"
#include "Scope.h"
#include "swift/AST/DiagnosticsCommon.h"
#include "swift/AST/DiagnosticsSIL.h"
#include "swift/AST/GenericEnvironment.h"
#include "swift/SIL/InstructionUtils.h"
#include "swift/SIL/MemAccessUtils.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"
using namespace swift;
using namespace Lowering;
//===----------------------------------------------------------------------===//
namespace {
struct LValueWritebackCleanup : Cleanup {
FormalEvaluationContext::stable_iterator Depth;
LValueWritebackCleanup() : Depth() {}
void emit(SILGenFunction &SGF, CleanupLocation loc,
ForUnwind_t forUnwind) override {
// TODO: honor forUnwind!
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.InFormalEvaluationScope);
// 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 bool areCertainlyEqualIndices(const Expr *e1, const Expr *e2);
void ExclusiveBorrowFormalAccess::diagnoseConflict(
const ExclusiveBorrowFormalAccess &rhs,
SILGenFunction &SGF) const {
// If the two writebacks we're comparing are of different kinds (e.g.
// ownership conversion vs a computed property) then they aren't the
// same and thus cannot conflict.
if (component->getKind() != rhs.component->getKind())
return;
// If the lvalues don't have the same base value (possibly null), then
// they aren't the same. Note that this is the primary source of false
// negative for this diagnostic.
SILValue lhsBaseValue = base.getValue(), rhsBaseValue = rhs.base.getValue();
if (lhsBaseValue != rhsBaseValue &&
(!lhsBaseValue || !rhsBaseValue ||
!RValue::areObviouslySameValue(lhsBaseValue, rhsBaseValue))) {
return;
}
auto lhsStorage = component->getAccessedStorage();
if (!lhsStorage) return;
auto rhsStorage = rhs.component->getAccessedStorage();
if (!rhsStorage) return;
// If the decls match, then this could conflict.
if (lhsStorage->Storage != rhsStorage->Storage ||
lhsStorage->IsSuper != rhsStorage->IsSuper)
return;
assert((lhsStorage->Indices != nullptr) == (rhsStorage->Indices != nullptr));
auto storage = lhsStorage->Storage;
// 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.
auto impl = storage->getImplInfo();
// TODO: Stored properties with didSet accessors that don't look at the
// oldValue could also be addressed.
if ((impl.getReadImpl() == ReadImplKind::Stored ||
impl.getReadImpl() == ReadImplKind::Address) &&
(impl.getWriteImpl() == WriteImplKind::Immutable ||
impl.getWriteImpl() == WriteImplKind::Stored ||
impl.getWriteImpl() == WriteImplKind::MutableAddress)) {
return;
}
// If the property is a generic requirement, allow aliases, because
// it may be conformed to using a stored property.
if (isa<ProtocolDecl>(storage->getDeclContext()))
return;
// If this is a simple property access, then we must have a conflict.
if (!lhsStorage->Indices) {
assert(isa<VarDecl>(storage));
SGF.SGM.diagnose(loc, diag::writeback_overlap_property,
storage->getBaseName().getIdentifier())
.highlight(loc.getSourceRange());
SGF.SGM.diagnose(rhs.loc, diag::writebackoverlap_note)
.highlight(rhs.loc.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 (!lhsStorage->Indices->isObviouslyEqual(*rhsStorage->Indices)) {
// If the index value doesn't lower to literally the same SILValue's,
// do some fuzzy matching to catch the common case.
if (!lhsStorage->IndexExprForDiagnostics ||
!rhsStorage->IndexExprForDiagnostics ||
!areCertainlyEqualIndices(lhsStorage->IndexExprForDiagnostics,
rhsStorage->IndexExprForDiagnostics))
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 = loc.getAsASTNode<SubscriptExpr>();
auto expr2 = rhs.loc.getAsASTNode<SubscriptExpr>();
if (expr1 && expr2) {
SGF.SGM.diagnose(loc, diag::writeback_overlap_subscript)
.highlight(expr1->getBase()->getSourceRange());
SGF.SGM.diagnose(rhs.loc, diag::writebackoverlap_note)
.highlight(expr2->getBase()->getSourceRange());
} else {
SGF.SGM.diagnose(loc, diag::writeback_overlap_subscript)
.highlight(loc.getSourceRange());
SGF.SGM.diagnose(rhs.loc, diag::writebackoverlap_note)
.highlight(rhs.loc.getSourceRange());
}
}
//===----------------------------------------------------------------------===//
static CanType getSubstFormalRValueType(Expr *expr) {
return expr->getType()->getRValueType()->getCanonicalType();
}
static LValueTypeData getLogicalStorageTypeData(SILGenModule &SGM,
CanType substFormalType) {
assert(!isa<ReferenceStorageType>(substFormalType));
AbstractionPattern origFormalType(
substFormalType.getReferenceStorageReferent());
return {
origFormalType,
substFormalType,
SGM.Types.getLoweredType(origFormalType, substFormalType).getObjectType()
};
}
static LValueTypeData getPhysicalStorageTypeData(SILGenModule &SGM,
AbstractStorageDecl *storage,
CanType substFormalType) {
assert(!isa<ReferenceStorageType>(substFormalType));
auto origFormalType = SGM.Types.getAbstractionPattern(storage)
.getReferenceStorageReferentType();
return {
origFormalType,
substFormalType,
SGM.Types.getLoweredType(origFormalType, substFormalType).getObjectType()
};
}
static bool shouldUseUnsafeEnforcement(VarDecl *var) {
if (var->isDebuggerVar())
return true;
// TODO: Check for the explicit "unsafe" attribute.
return false;
}
Optional<SILAccessEnforcement>
SILGenFunction::getStaticEnforcement(VarDecl *var) {
if (var && shouldUseUnsafeEnforcement(var))
return SILAccessEnforcement::Unsafe;
return SILAccessEnforcement::Static;
}
Optional<SILAccessEnforcement>
SILGenFunction::getDynamicEnforcement(VarDecl *var) {
if (getOptions().EnforceExclusivityDynamic) {
if (var && shouldUseUnsafeEnforcement(var))
return SILAccessEnforcement::Unsafe;
return SILAccessEnforcement::Dynamic;
}
return None;
}
Optional<SILAccessEnforcement>
SILGenFunction::getUnknownEnforcement(VarDecl *var) {
if (var && shouldUseUnsafeEnforcement(var))
return SILAccessEnforcement::Unsafe;
return SILAccessEnforcement::Unknown;
}
/// SILGenLValue - An ASTVisitor for building logical lvalues.
class LLVM_LIBRARY_VISIBILITY SILGenLValue
: public Lowering::ExprVisitor<SILGenLValue, LValue,
AccessKind, LValueOptions>
{
public:
SILGenFunction &SGF;
SILGenLValue(SILGenFunction &SGF) : SGF(SGF) {}
LValue visitRec(Expr *e, AccessKind accessKind, LValueOptions options,
AbstractionPattern orig = AbstractionPattern::getInvalid());
/// Dummy handler to log unimplemented nodes.
LValue visitExpr(Expr *e, AccessKind accessKind, LValueOptions options);
// Nodes that form the root of lvalue paths
LValue visitDiscardAssignmentExpr(DiscardAssignmentExpr *e,
AccessKind accessKind,
LValueOptions options);
LValue visitDeclRefExpr(DeclRefExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitOpaqueValueExpr(OpaqueValueExpr *e, AccessKind accessKind,
LValueOptions options);
// Nodes that make up components of lvalue paths
LValue visitMemberRefExpr(MemberRefExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitSubscriptExpr(SubscriptExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitTupleElementExpr(TupleElementExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitForceValueExpr(ForceValueExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitBindOptionalExpr(BindOptionalExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitOpenExistentialExpr(OpenExistentialExpr *e,
AccessKind accessKind,
LValueOptions options);
LValue visitKeyPathApplicationExpr(KeyPathApplicationExpr *e,
AccessKind accessKind,
LValueOptions options);
// Expressions that wrap lvalues
LValue visitInOutExpr(InOutExpr *e, AccessKind accessKind,
LValueOptions options);
LValue visitDotSyntaxBaseIgnoredExpr(DotSyntaxBaseIgnoredExpr *e,
AccessKind accessKind,
LValueOptions options);
};
/// Materialize this component into a temporary.
ManagedValue LogicalPathComponent::materializeIntoTemporary(
SILGenFunction &SGF, SILLocation loc, ManagedValue base) && {
const TypeLowering &RValueTL = SGF.getTypeLowering(getTypeOfRValue());
TemporaryInitializationPtr tempInit;
RValue rvalue;
// If the RValue type has an openedExistential, then the RValue must be
// materialized before allocating a temporary for the RValue type. In that
// case, the RValue cannot be emitted directly into the temporary.
if (getTypeOfRValue().hasOpenedExistential()) {
// Emit a 'get'.
rvalue = std::move(*this).get(SGF, loc, base, SGFContext());
// Create a temporary, whose type may depend on the 'get'.
tempInit = SGF.emitFormalAccessTemporary(loc, RValueTL);
} else {
// Create a temporary for a static (non-dependent) RValue type.
tempInit = SGF.emitFormalAccessTemporary(loc, RValueTL);
// Emit a 'get' directly into the temporary.
rvalue = std::move(*this).get(SGF, loc, base, SGFContext(tempInit.get()));
}
// `this` is now dead.
// Force `value` into a temporary if is wasn't emitted there.
if (!rvalue.isInContext())
std::move(rvalue).forwardInto(SGF, loc, tempInit.get());
return tempInit->getManagedAddress();
}
ManagedValue LogicalPathComponent::getMaterialized(SILGenFunction &SGF,
SILLocation loc,
ManagedValue base,
AccessKind kind) && {
if (kind == AccessKind::Read)
return std::move(*this).materializeIntoTemporary(SGF, loc, base);
// AccessKind is Write or ReadWrite. We need to emit a get and set.
assert(SGF.InFormalEvaluationScope &&
"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 temp = std::move(*this).materializeIntoTemporary(SGF, loc, base);
if (SGF.getOptions().VerifyExclusivity) {
// Begin an access of the temporary. It is unenforced because enforcement
// isn't required for RValues.
SILValue accessAddress = UnenforcedFormalAccess::enter(
SGF, loc, temp.getValue(), SILAccessKind::Modify);
temp = std::move(temp).transform(accessAddress);
}
// Push a writeback for the temporary.
pushWriteback(SGF, loc, std::move(clonedComponent), base,
MaterializedLValue(temp));
return temp.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 (base && !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, ArgumentSource(loc, std::move(rvalue)),
base);
}
InOutConversionScope::InOutConversionScope(SILGenFunction &SGF)
: SGF(SGF)
{
assert(SGF.InFormalEvaluationScope
&& "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 {
dump(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 {
/// A helper class for creating writebacks associated with l-value
/// components that don't really need them.
class WritebackPseudoComponent : public LogicalPathComponent {
protected:
WritebackPseudoComponent(const LValueTypeData &typeData)
: LogicalPathComponent(typeData, WritebackPseudoKind) {}
public:
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,
ArgumentSource &&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");
}
Optional<AccessedStorage> getAccessedStorage() const override {
return None;
}
};
class EndAccessPseudoComponent : public WritebackPseudoComponent {
public:
EndAccessPseudoComponent(const LValueTypeData &typeData)
: WritebackPseudoComponent(typeData) {}
private:
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) override {
loc.markAutoGenerated();
assert(base.isLValue());
SGF.B.createEndAccess(loc, base.getValue(), /*abort*/ false);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "EndAccessPseudoComponent\n";
}
};
} // end anonymous namespace
static SILValue enterAccessScope(SILGenFunction &SGF, SILLocation loc,
SILValue addr, LValueTypeData typeData,
AccessKind accessKind,
SILAccessEnforcement enforcement) {
auto silAccessKind = [&] {
switch (accessKind) {
case AccessKind::Read:
return SILAccessKind::Read;
case AccessKind::Write:
case AccessKind::ReadWrite:
return SILAccessKind::Modify;
}
}();
// Hack for materializeForSet emission, where we can't safely
// push a begin/end access.
if (!SGF.InFormalEvaluationScope) {
auto unpairedAccesses = SGF.UnpairedAccessesForMaterializeForSet;
assert(unpairedAccesses &&
"tried to enter access scope without a writeback scope!");
if (enforcement == SILAccessEnforcement::Dynamic) {
SGF.B.createBeginUnpairedAccess(loc, addr, unpairedAccesses->Buffer,
silAccessKind, enforcement,
/*hasNoNestedConflict=*/false,
/*fromBuiltin=*/false);
unpairedAccesses->NumAccesses++;
}
return addr;
}
// Enter the access.
addr = SGF.B.createBeginAccess(loc, addr, silAccessKind, enforcement,
/*hasNoNestedConflict=*/false,
/*fromBuiltin=*/false);
// Push a writeback to end it.
auto accessedMV = ManagedValue::forLValue(addr);
std::unique_ptr<LogicalPathComponent>
component(new EndAccessPseudoComponent(typeData));
pushWriteback(SGF, loc, std::move(component), accessedMV,
MaterializedLValue());
return addr;
}
static ManagedValue enterAccessScope(SILGenFunction &SGF, SILLocation loc,
ManagedValue addr, LValueTypeData typeData,
AccessKind accessKind,
SILAccessEnforcement enforcement) {
return ManagedValue::forLValue(
enterAccessScope(SGF, loc, addr.getLValueAddress(), typeData,
accessKind, enforcement));
}
// Find the base of the formal access at `address`. If the base requires an
// access marker, then create a begin_access on `address`. Return the
// address to be used for the access.
//
// FIXME: In order to generate more consistent and verifiable SIL patterns, or
// subobject projections, create the access on the base address and recreate the
// projection.
SILValue UnenforcedAccess::beginAccess(SILGenFunction &SGF, SILLocation loc,
SILValue address, SILAccessKind kind) {
if (!SGF.getOptions().VerifyExclusivity)
return address;
const AccessedStorage &storage = findAccessedStorage(address);
// Unsafe access may have invalid storage (e.g. a RawPointer).
if (storage && !isPossibleFormalAccessBase(storage, &SGF.F))
return address;
auto BAI =
SGF.B.createBeginAccess(loc, address, kind, SILAccessEnforcement::Unsafe,
/*hasNoNestedConflict=*/false,
/*fromBuiltin=*/false);
beginAccessPtr = BeginAccessPtr(BAI, DeleterCheck());
return BAI;
}
void UnenforcedAccess::endAccess(SILGenFunction &SGF) {
emitEndAccess(SGF);
beginAccessPtr.release();
}
void UnenforcedAccess::emitEndAccess(SILGenFunction &SGF) {
if (!beginAccessPtr)
return;
SGF.B.createEndAccess(beginAccessPtr->getLoc(), beginAccessPtr.get(),
/*abort*/ false);
}
// Emit an end_access marker when executing a cleanup (on a side branch).
void UnenforcedFormalAccess::emitEndAccess(SILGenFunction &SGF) {
access.emitEndAccess(SGF);
}
// End the access when existing the FormalEvaluationScope.
void UnenforcedFormalAccess::finishImpl(SILGenFunction &SGF) {
access.endAccess(SGF);
}
namespace {
struct UnenforcedAccessCleanup : Cleanup {
FormalEvaluationContext::stable_iterator Depth;
UnenforcedAccessCleanup() : Depth() {}
void emit(SILGenFunction &SGF, CleanupLocation loc,
ForUnwind_t forUnwind) override {
auto &evaluation = *SGF.FormalEvalContext.find(Depth);
assert(evaluation.getKind() == FormalAccess::Unenforced);
auto &formalAccess = static_cast<UnenforcedFormalAccess &>(evaluation);
formalAccess.emitEndAccess(SGF);
}
void dump(SILGenFunction &) const override {
#ifndef NDEBUG
llvm::errs() << "UnenforcedAccessCleanup\n"
<< "State: " << getState() << " Depth: " << Depth.getDepth()
<< "\n";
#endif
}
};
} // end anonymous namespace
SILValue UnenforcedFormalAccess::enter(SILGenFunction &SGF, SILLocation loc,
SILValue address, SILAccessKind kind) {
assert(SGF.InFormalEvaluationScope);
UnenforcedAccess access;
SILValue accessAddress = access.beginAccess(SGF, loc, address, kind);
if (!access.beginAccessPtr)
return address;
auto &cleanup = SGF.Cleanups.pushCleanup<UnenforcedAccessCleanup>();
CleanupHandle handle = SGF.Cleanups.getTopCleanup();
auto &context = SGF.FormalEvalContext;
context.push<UnenforcedFormalAccess>(loc, std::move(access), handle);
cleanup.Depth = context.stable_begin();
return accessAddress;
}
static void copyBorrowedYieldsIntoTemporary(SILGenFunction &SGF,
SILLocation loc,
ArrayRef<ManagedValue> &yields,
AbstractionPattern origFormalType,
CanType substFormalType,
Initialization *init) {
if (!origFormalType.isTuple()) {
auto value = yields.front();
yields = yields.drop_front();
init->copyOrInitValueInto(SGF, loc, value, /*isInit*/ false);
init->finishInitialization(SGF);
return;
}
assert(init->canSplitIntoTupleElements());
SmallVector<InitializationPtr, 4> scratch;
auto eltInits =
init->splitIntoTupleElements(SGF, loc, substFormalType, scratch);
for (size_t i : indices(eltInits)) {
auto origEltType = origFormalType.getTupleElementType(i);
auto substEltType = cast<TupleType>(substFormalType).getElementType(i);
copyBorrowedYieldsIntoTemporary(SGF, loc, yields, origEltType,
substEltType, eltInits[i].get());
}
init->finishInitialization(SGF);
}
namespace {
class RefElementComponent : public PhysicalPathComponent {
VarDecl *Field;
SILType SubstFieldType;
bool IsNonAccessing;
public:
RefElementComponent(VarDecl *field, LValueOptions options,
SILType substFieldType, LValueTypeData typeData)
: PhysicalPathComponent(typeData, RefElementKind),
Field(field), SubstFieldType(substFieldType),
IsNonAccessing(options.IsNonAccessing) {}
virtual bool isLoadingPure() const override { return true; }
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);
SILValue result =
SGF.B.createRefElementAddr(loc, base.getUnmanagedValue(),
Field, SubstFieldType);
// Avoid emitting access markers completely for non-accesses or immutable
// declarations. Access marker verification is aware of these cases.
if (!IsNonAccessing && !Field->isLet()) {
if (auto enforcement = SGF.getDynamicEnforcement(Field)) {
result = enterAccessScope(SGF, loc, result, getTypeData(),
accessKind, *enforcement);
}
}
return ManagedValue::forLValue(result);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "RefElementComponent(" << Field->getName() << ")\n";
}
};
class TupleElementComponent : public PhysicalPathComponent {
unsigned ElementIndex;
public:
TupleElementComponent(unsigned elementIndex, LValueTypeData typeData)
: PhysicalPathComponent(typeData, TupleElementKind),
ElementIndex(elementIndex) {}
virtual bool isLoadingPure() const override { return true; }
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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "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) {}
virtual bool isLoadingPure() const override { return true; }
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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "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 {
bool isImplicitUnwrap;
public:
ForceOptionalObjectComponent(LValueTypeData typeData,
bool isImplicitUnwrap)
: PhysicalPathComponent(typeData, OptionalObjectKind),
isImplicitUnwrap(isImplicitUnwrap) {}
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, isImplicitUnwrap);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "ForceOptionalObjectComponent(" << isImplicitUnwrap << ")\n";
}
};
/// A physical path component which projects out an opened archetype
/// from an existential.
class OpenOpaqueExistentialComponent : public PhysicalPathComponent {
public:
OpenOpaqueExistentialComponent(CanArchetypeType openedArchetype,
LValueTypeData typeData)
: PhysicalPathComponent(typeData, OpenOpaqueExistentialKind) {
assert(getSubstFormalType() == openedArchetype);
}
virtual bool isLoadingPure() const override { return true; }
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(base.getType().isExistentialType() &&
"base for open existential component must be an existential");
assert(base.getType().isAddress() &&
"base value of open-existential component was not an address?");
SILValue addr;
auto rep = base.getType().getPreferredExistentialRepresentation(SGF.SGM.M);
switch (rep) {
case ExistentialRepresentation::Opaque:
addr = SGF.B.createOpenExistentialAddr(
loc, base.getValue(), getTypeOfRValue().getAddressType(),
getOpenedExistentialAccessFor(accessKind));
break;
case ExistentialRepresentation::Boxed: {
auto &TL = SGF.getTypeLowering(base.getType());
auto error = SGF.emitLoad(loc, base.getValue(), TL,
SGFContext(), IsNotTake);
addr = SGF.B.createOpenExistentialBox(
loc, error.getValue(), getTypeOfRValue().getAddressType());
break;
}
default:
llvm_unreachable("Bad existential representation for address-only type");
}
return ManagedValue::forLValue(addr);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "OpenOpaqueExistentialComponent("
<< getSubstFormalType() << ")\n";
}
};
/// A local path component for the payload of a class or metatype existential.
///
/// TODO: Could be physical if we had a way to project out the
/// payload.
class OpenNonOpaqueExistentialComponent : public LogicalPathComponent {
CanArchetypeType OpenedArchetype;
public:
OpenNonOpaqueExistentialComponent(CanArchetypeType openedArchetype,
LValueTypeData typeData)
: LogicalPathComponent(typeData, OpenNonOpaqueExistentialKind),
OpenedArchetype(openedArchetype) {}
virtual bool isLoadingPure() const override { return true; }
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
// Always use the same access kind for the base.
return kind;
}
Optional<AccessedStorage> getAccessedStorage() const override {
return None;
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && override {
auto refType = base.getType().getObjectType();
auto &TL = SGF.getTypeLowering(refType);
// Load the original value.
auto result = SGF.emitLoad(loc, base.getValue(), TL,
SGFContext(), IsNotTake);
assert(refType.isAnyExistentialType() &&
"base for open existential component must be an existential");
ManagedValue ref;
if (refType.is<ExistentialMetatypeType>()) {
assert(refType.getPreferredExistentialRepresentation(SGF.SGM.M)
== ExistentialRepresentation::Metatype);
ref = ManagedValue::forUnmanaged(
SGF.B.createOpenExistentialMetatype(loc,
result.getUnmanagedValue(),
getTypeOfRValue()));
} else {
assert(refType.getPreferredExistentialRepresentation(SGF.SGM.M)
== ExistentialRepresentation::Class);
ref = SGF.B.createOpenExistentialRef(loc, result, getTypeOfRValue());
}
return RValue(SGF, loc, getSubstFormalType(), ref);
}
void set(SILGenFunction &SGF, SILLocation loc,
ArgumentSource &&value, ManagedValue base) && override {
auto payload = std::move(value).getAsSingleValue(SGF).forward(SGF);
SmallVector<ProtocolConformanceRef, 2> conformances;
for (auto proto : OpenedArchetype->getConformsTo())
conformances.push_back(ProtocolConformanceRef(proto));
SILValue ref;
if (base.getType().is<ExistentialMetatypeType>()) {
ref = SGF.B.createInitExistentialMetatype(
loc,
payload,
base.getType().getObjectType(),
SGF.getASTContext().AllocateCopy(conformances));
} else {
assert(getSubstFormalType()->isBridgeableObjectType());
ref = SGF.B.createInitExistentialRef(
loc,
base.getType().getObjectType(),
getSubstFormalType(),
payload,
SGF.getASTContext().AllocateCopy(conformances));
}
auto &TL = SGF.getTypeLowering(base.getType());
SGF.emitSemanticStore(loc, ref,
base.getValue(), TL, IsNotInitialization);
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
LogicalPathComponent *clone =
new OpenNonOpaqueExistentialComponent(OpenedArchetype, getTypeData());
return std::unique_ptr<LogicalPathComponent>(clone);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "OpenNonOpaqueExistentialComponent("
<< OpenedArchetype << ", ...)\n";
}
};
/// A physical path component which returns a literal address.
class ValueComponent : public PhysicalPathComponent {
ManagedValue Value;
Optional<SILAccessEnforcement> Enforcement;
bool IsRValue;
public:
ValueComponent(ManagedValue value,
Optional<SILAccessEnforcement> enforcement,
LValueTypeData typeData,
bool isRValue = false) :
PhysicalPathComponent(typeData, ValueKind),
Value(value),
Enforcement(enforcement),
IsRValue(isRValue) {
assert(IsRValue || value.getType().isAddress());
}
virtual bool isLoadingPure() const override { return true; }
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(!base && "value component must be root of lvalue path");
if (!Enforcement)
return Value;
SILValue addr = Value.getLValueAddress();
addr = enterAccessScope(SGF, loc, addr, getTypeData(),
accessKind, *Enforcement);
return ManagedValue::forLValue(addr);
}
bool isRValue() const override {
return IsRValue;
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS << "ValueComponent(";
if (IsRValue) OS << "rvalue, ";
if (Enforcement) {
OS << getSILAccessEnforcementName(*Enforcement);
} else {
OS << "unenforced";
}
OS << "):\n";
Value.dump(OS, indent + 2);
}
};
} // 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() == DeclBaseName::createConstructor() &&
!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->getType()->isEqual(dre2->getType());
}
// 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;
}
static LValueOptions getBaseOptions(LValueOptions options,
AccessStrategy strategy) {
return (strategy.getKind() == AccessStrategy::Storage
? options.forProjectedBaseLValue()
: options.forComputedBaseLValue());
}
static ArgumentSource emitBaseValueForAccessor(SILGenFunction &SGF,
SILLocation loc, LValue &&dest,
CanType baseFormalType,
SILDeclRef accessor);
static AccessKind getBaseAccessKind(AbstractStorageDecl *member,
AccessKind accessKind,
AccessStrategy strategy);
namespace {
/// A helper class for implementing components that involve accessing
/// storage.
template <class Base>
class AccessComponent : public Base {
protected:
// The VarDecl or SubscriptDecl being get/set.
AbstractStorageDecl *Storage;
/// The subscript index expression. Useless
Expr *IndexExprForDiagnostics;
RValue Indices;
/// AST type of the base expression, in case the accessor call
/// requires re-abstraction.
CanType BaseFormalType;
struct AccessorArgs {
ArgumentSource base;
RValue Indices;
};
/// 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 (!Indices.isNull())
result.Indices = std::move(Indices);
return result;
}
AccessComponent(PathComponent::KindTy kind,
AbstractStorageDecl *storage,
CanType baseFormalType,
LValueTypeData typeData,
Expr *indexExprForDiagnostics,
RValue *optSubscripts)
: Base(typeData, kind), Storage(storage),
IndexExprForDiagnostics(indexExprForDiagnostics),
BaseFormalType(baseFormalType)
{
if (optSubscripts)
Indices = std::move(*optSubscripts);
}
AccessComponent(const AccessComponent &copied,
SILGenFunction &SGF,
SILLocation loc)
: Base(copied.getTypeData(), copied.getKind()),
Storage(copied.Storage),
IndexExprForDiagnostics(copied.IndexExprForDiagnostics),
Indices(copied.Indices.copy(SGF, loc)) ,
BaseFormalType(copied.BaseFormalType) {}
bool doesAccessorMutateSelf(SILGenFunction &SGF,
SILDeclRef accessor) const {
auto accessorSelf = SGF.SGM.Types.getConstantSelfParameter(accessor);
return accessorSelf.getType() && accessorSelf.isIndirectMutating();
}
void printBase(raw_ostream &OS, unsigned indent, StringRef name) const {
OS.indent(indent) << name << "(" << Storage->getBaseName() << ")";
if (IndexExprForDiagnostics) {
OS << " subscript_index:\n";
IndexExprForDiagnostics->print(OS, 2);
}
OS << '\n';
}
};
/// A helper class for implementing a component that involves
/// calling accessors.
template <class Base>
class AccessorBasedComponent : public AccessComponent<Base> {
using super = AccessComponent<Base>;
protected:
SILDeclRef Accessor;
bool IsSuper;
bool IsDirectAccessorUse;
SubstitutionMap Substitutions;
public:
AccessorBasedComponent(PathComponent::KindTy kind,
AbstractStorageDecl *decl,
SILDeclRef accessor,
bool isSuper, bool isDirectAccessorUse,
SubstitutionMap substitutions,
CanType baseFormalType,
LValueTypeData typeData,
Expr *indexExprForDiagnostics,
RValue *optIndices)
: super(kind, decl, baseFormalType, typeData,
indexExprForDiagnostics, optIndices),
Accessor(accessor), IsSuper(isSuper),
IsDirectAccessorUse(isDirectAccessorUse),
Substitutions(substitutions) {}
AccessorBasedComponent(const AccessorBasedComponent &copied,
SILGenFunction &SGF,
SILLocation loc)
: super(copied, SGF, loc),
Accessor(copied.Accessor),
IsSuper(copied.IsSuper),
IsDirectAccessorUse(copied.IsDirectAccessorUse),
Substitutions(copied.Substitutions) {}
AccessorDecl *getAccessorDecl() const {
return cast<AccessorDecl>(Accessor.getFuncDecl());
}
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
if (this->doesAccessorMutateSelf(SGF, Accessor))
return AccessKind::ReadWrite;
else
return AccessKind::Read;
}
};
class GetterSetterComponent
: public AccessorBasedComponent<LogicalPathComponent> {
public:
GetterSetterComponent(AbstractStorageDecl *decl,
SILDeclRef accessor,
bool isSuper, bool isDirectAccessorUse,
SubstitutionMap substitutions,
CanType baseFormalType,
LValueTypeData typeData,
Expr *subscriptIndexExpr = nullptr,
RValue *subscriptIndex = nullptr)
: AccessorBasedComponent(GetterSetterKind, decl, accessor, isSuper,
isDirectAccessorUse, substitutions,
baseFormalType, typeData, subscriptIndexExpr,
subscriptIndex)
{
assert(getAccessorDecl()->isGetterOrSetter() ||
getAccessorDecl()->isMaterializeForSet());
}
GetterSetterComponent(const GetterSetterComponent &copied,
SILGenFunction &SGF,
SILLocation loc)
: AccessorBasedComponent(copied, SGF, loc)
{
}
void emitAssignWithSetter(SILGenFunction &SGF, SILLocation loc,
LValue &&dest, ArgumentSource &&value) {
assert(getAccessorDecl()->isSetter());
SILDeclRef setter = Accessor;
// Pull everything out of this that we'll need, because we're
// about to modify the LValue and delete this component.
auto subs = this->Substitutions;
bool isSuper = this->IsSuper;
bool isDirectAccessorUse = this->IsDirectAccessorUse;
RValue indices = std::move(this->Indices);
auto baseFormalType = this->BaseFormalType;
// Drop this component from the l-value.
dest.dropLastComponent(*this);
return emitAssignWithSetter(SGF, loc, std::move(dest), baseFormalType,
isSuper, setter, isDirectAccessorUse,
subs, std::move(indices), std::move(value));
}
static void emitAssignWithSetter(SILGenFunction &SGF, SILLocation loc,
LValue &&baseLV, CanType baseFormalType,
bool isSuper, SILDeclRef setter,
bool isDirectAccessorUse,
SubstitutionMap subs,
RValue &&indices, ArgumentSource &&value) {
ArgumentSource self = [&] {
if (!baseLV.isValid()) {
return ArgumentSource();
} else if (computeSelfParam(cast<FuncDecl>(setter.getDecl()))
.getParameterFlags().isInOut()) {
return ArgumentSource(loc, std::move(baseLV));
} else {
return emitBaseValueForAccessor(SGF, loc, std::move(baseLV),
baseFormalType, setter);
}
}();
return SGF.emitSetAccessor(loc, setter, subs, std::move(self),
isSuper, isDirectAccessorUse,
std::move(indices), std::move(value));
}
void set(SILGenFunction &SGF, SILLocation loc,
ArgumentSource &&value, ManagedValue base) && override {
assert(getAccessorDecl()->isSetter());
SILDeclRef setter = Accessor;
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.Indices),
std::move(value));
}
ManagedValue getMaterialized(SILGenFunction &SGF,
SILLocation loc,
ManagedValue base,
AccessKind accessKind) && override {
assert(accessKind == AccessKind::Read ||
accessKind == AccessKind::ReadWrite);
if (accessKind == AccessKind::Read) {
return std::move(*this).LogicalPathComponent::getMaterialized(SGF,
loc, base, accessKind);
}
assert(getAccessorDecl()->isMaterializeForSet());
assert(Storage->getMaterializeForSetFunc() &&
"polymorphic storage without materializeForSet");
assert(SGF.InFormalEvaluationScope &&
"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 borrowedIndices;
RValue *optIndices = nullptr;
if (!Indices.isNull()) {
CanType type = Indices.getType();
SmallVector<ManagedValue, 4> values;
std::move(Indices).getAll(values);
Indices = RValue(SGF, values, type);
borrowedIndices = RValue(SGF, values, type);
optIndices = &borrowedIndices;
}
return new GetterSetterComponent(Storage, Accessor, IsSuper,
IsDirectAccessorUse,
Substitutions, BaseFormalType,
getTypeData(), IndexExprForDiagnostics,
optIndices);
}());
SILDeclRef materializeForSet = Accessor;
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.Indices), 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.getLValueAddress();
materialized.temporary = ManagedValue::forLValue(
SGF.B.createMarkDependence(loc, temporary, base.getValue()));
}
}
// Enter an access scope for the temporary.
materialized.temporary =
enterAccessScope(SGF, loc, materialized.temporary, getTypeData(),
accessKind, SILAccessEnforcement::Unsafe);
// 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;
Optional<ProtocolConformanceRef> witnessMethodConformance;
if (auto proto = dyn_cast<ProtocolDecl>(Storage->getDeclContext())) {
rep = SILFunctionTypeRepresentation::WitnessMethod;
witnessMethodConformance = ProtocolConformanceRef(proto);
} else {
rep = SILFunctionTypeRepresentation::Method;
}
auto origCallbackFnType =
SGF.SGM.Types.getMaterializeForSetCallbackType(
Storage, materialized.genericSig, materialized.origSelfType,
rep, witnessMethodConformance);
auto origCallbackType = SILType::getPrimitiveObjectType(origCallbackFnType);
callback = SGF.B.createPointerToThinFunction(loc, callback, origCallbackType);
auto substCallbackFnType = origCallbackFnType->substGenericArgs(
M, Substitutions);
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;
UnenforcedAccess baseAccess;
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());
// Create an unenforced formal access for the temporary base, which
// is passed @inout to the callback.
baseAddress = baseAccess.beginAccess(SGF, loc, baseAddress,
SILAccessKind::Modify);
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,
Substitutions, {
temporaryPointer,
materialized.callbackStorage,
baseAddress,
baseMetatype
}, false);
if (baseAccess.beginAccessPtr)
baseAccess.endAccess(SGF);
}
// Continue.
SGF.B.emitBlock(contBB, loc);
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext c) && override {
assert(getAccessorDecl()->isGetter());
SILDeclRef getter = Accessor;
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.Indices), 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 dump(raw_ostream &OS, unsigned indent) const override {
printBase(OS, indent, "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.
Optional<AccessedStorage> getAccessedStorage() const override {
return AccessedStorage{Storage, IsSuper,
Indices.isNull() ? nullptr : &Indices,
IndexExprForDiagnostics };
}
};
class UnpinPseudoComponent : public WritebackPseudoComponent {
public:
UnpinPseudoComponent(const LValueTypeData &typeData)
: WritebackPseudoComponent(typeData) {}
private:
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) override {
loc.markAutoGenerated();
// 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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "UnpinPseudoComponent";
}
};
class MaterializeToTemporaryComponent final
: public AccessComponent<LogicalPathComponent> {
SubstitutionMap Substitutions;
AccessStrategy ReadStrategy;
AccessStrategy WriteStrategy;
LValueOptions Options;
bool IsSuper;
public:
MaterializeToTemporaryComponent(AbstractStorageDecl *storage,
bool isSuper, SubstitutionMap subs,
LValueOptions options,
AccessStrategy readStrategy,
AccessStrategy writeStrategy,
CanType baseFormalType,
LValueTypeData typeData,
Expr *indexExprForDiagnostics,
RValue *optIndices)
: AccessComponent(MaterializeToTemporaryKind, storage, baseFormalType,
typeData, indexExprForDiagnostics, optIndices),
Substitutions(subs),
ReadStrategy(readStrategy), WriteStrategy(writeStrategy),
Options(options), IsSuper(isSuper) {}
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
return combineAccessKinds(
::getBaseAccessKind(Storage, AccessKind::Read, ReadStrategy),
::getBaseAccessKind(Storage, AccessKind::Write, WriteStrategy));
}
std::unique_ptr<LogicalPathComponent>
clone(SILGenFunction &SGF, SILLocation loc) const override {
RValue clonedIndicesBuffer;
RValue *clonedIndices = nullptr;
if (!Indices.isNull()) {
clonedIndicesBuffer = Indices.copy(SGF, loc);
clonedIndices = &clonedIndicesBuffer;
}
LogicalPathComponent *clone =
new MaterializeToTemporaryComponent(Storage, IsSuper, Substitutions,
Options,
ReadStrategy, WriteStrategy,
BaseFormalType, getTypeData(),
IndexExprForDiagnostics,
clonedIndices);
return std::unique_ptr<LogicalPathComponent>(clone);
}
RValue get(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, SGFContext C) && override {
LValue lv = std::move(*this).prepareLValue(SGF, loc, base, ReadStrategy);
return SGF.emitLoadOfLValue(loc, std::move(lv), C);
}
void set(SILGenFunction &SGF, SILLocation loc,
ArgumentSource &&value, ManagedValue base) && override {
LValue lv = std::move(*this).prepareLValue(SGF, loc, base, WriteStrategy);
return SGF.emitAssignToLValue(loc, std::move(value), std::move(lv));
}
Optional<AccessedStorage> getAccessedStorage() const override {
return AccessedStorage{Storage, IsSuper,
Indices.isNull() ? nullptr : &Indices,
IndexExprForDiagnostics};
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "MaterializeToTemporaryComponent";
}
private:
LValue prepareLValue(SILGenFunction &SGF, SILLocation loc,
ManagedValue base, AccessStrategy strategy) && {
LValue lv = (base ? LValue::forValue(base, BaseFormalType) : LValue());
if (auto subscript = dyn_cast<SubscriptDecl>(Storage)) {
lv.addMemberSubscriptComponent(SGF, loc, subscript, Substitutions,
Options, IsSuper, strategy,
getSubstFormalType(),
std::move(Indices),
IndexExprForDiagnostics);
} else {
auto var = cast<VarDecl>(Storage);
if (base) {
lv.addMemberVarComponent(SGF, loc, var, Substitutions, Options,
IsSuper, strategy, getSubstFormalType());
} else {
lv.addNonMemberVarComponent(SGF, loc, var, Substitutions, Options,
strategy, getSubstFormalType());
}
}
return lv;
}
};
/// A physical component which involves calling addressors.
class AddressorComponent
: public AccessorBasedComponent<PhysicalPathComponent> {
SILType SubstFieldType;
public:
AddressorComponent(AbstractStorageDecl *decl, SILDeclRef accessor,
bool isSuper, bool isDirectAccessorUse,
SubstitutionMap substitutions,
CanType baseFormalType, LValueTypeData typeData,
SILType substFieldType,
Expr *subscriptIndexExpr = nullptr,
RValue *subscriptIndex = nullptr)
: AccessorBasedComponent(AddressorKind, decl, accessor, isSuper,
isDirectAccessorUse, substitutions,
baseFormalType, typeData, subscriptIndexExpr,
subscriptIndex),
SubstFieldType(substFieldType)
{
assert(getAccessorDecl()->isAnyAddressor());
}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(SGF.InFormalEvaluationScope &&
"offsetting l-value for modification without writeback scope");
std::pair<ManagedValue, ManagedValue> result;
{
FormalEvaluationScope scope(SGF);
auto args =
std::move(*this).prepareAccessorArgs(SGF, loc, base, Accessor);
result = SGF.emitAddressorAccessor(
loc, Accessor, Substitutions, std::move(args.base),
IsSuper, IsDirectAccessorUse,
std::move(args.Indices), SubstFieldType);
}
switch (getAccessorDecl()->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);
break;
// For owning addressors, we can just let the owner get released
// at an appropriate point.
case AddressorKind::Owning:
case AddressorKind::NativeOwning:
break;
// 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());
break;
}
}
// Enter an unsafe access scope for the access.
auto addr = result.first;
addr = enterAccessScope(SGF, loc, addr, getTypeData(), accessKind,
SILAccessEnforcement::Unsafe);
return addr;
}
void dump(raw_ostream &OS, unsigned indent) const override {
printBase(OS, indent, "AddressorComponent");
}
};
class EndApplyPseudoComponent : public WritebackPseudoComponent {
CleanupHandle EndApplyHandle;
public:
EndApplyPseudoComponent(const LValueTypeData &typeData,
CleanupHandle endApplyHandle)
: WritebackPseudoComponent(typeData), EndApplyHandle(endApplyHandle) {}
private:
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) override {
SGF.Cleanups.popAndEmitCleanup(EndApplyHandle, CleanupLocation::get(loc),
NotForUnwind);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "EndApplyPseudoComponent";
}
};
/// A physical component which involves calling coroutine accessors.
class CoroutineAccessorComponent
: public AccessorBasedComponent<PhysicalPathComponent> {
public:
CoroutineAccessorComponent(AbstractStorageDecl *decl,
SILDeclRef accessor,
bool isSuper, bool isDirectAccessorUse,
SubstitutionMap substitutions,
CanType baseFormalType,
LValueTypeData typeData,
Expr *indexExprForDiagnostics = nullptr,
RValue *optIndices = nullptr)
: AccessorBasedComponent(CoroutineAccessorKind,
decl, accessor, isSuper, isDirectAccessorUse,
substitutions, baseFormalType, typeData,
indexExprForDiagnostics, optIndices) {
}
using AccessorBasedComponent::AccessorBasedComponent;
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(SGF.InFormalEvaluationScope &&
"offsetting l-value for modification without writeback scope");
ManagedValue result;
auto args =
std::move(*this).prepareAccessorArgs(SGF, loc, base, Accessor);
SmallVector<ManagedValue, 4> yields;
auto endApplyHandle =
SGF.emitCoroutineAccessor(
loc, Accessor, Substitutions, std::move(args.base), IsSuper,
IsDirectAccessorUse, std::move(args.Indices), yields);
// Push a writeback that ends the access.
std::unique_ptr<LogicalPathComponent>
component(new EndApplyPseudoComponent(getTypeData(), endApplyHandle));
pushWriteback(SGF, loc, std::move(component), ManagedValue(),
MaterializedLValue());
auto decl = cast<AccessorDecl>(Accessor.getFuncDecl());
// 'modify' always returns an address of the right type.
if (decl->getAccessorKind() == AccessorKind::Modify) {
assert(yields.size() == 1);
return yields[0];
}
// 'read' returns a borrowed r-value, which might or might not be
// an address of the right type.
// Use the address if we have one.
if (!getOrigFormalType().isTuple()) {
assert(yields.size() == 1);
if (yields[0].isLValue()) {
return yields[0];
}
}
// Otherwise, we need to make a temporary.
auto temporary =
SGF.emitTemporary(loc, SGF.getTypeLowering(getTypeOfRValue()));
auto yieldsAsArray = llvm::makeArrayRef(yields);
copyBorrowedYieldsIntoTemporary(SGF, loc, yieldsAsArray,
getOrigFormalType(), getSubstFormalType(),
temporary.get());
assert(yieldsAsArray.empty() && "didn't claim all yields");
return temporary->getManagedAddress();
}
void dump(raw_ostream &OS, unsigned indent) const override {
printBase(OS, indent, "CoroutineAccessorComponent");
}
};
/// A physical component which involves applying a key path.
class KeyPathApplicationComponent final : public PhysicalPathComponent {
ArgumentSource KeyPath;
public:
KeyPathApplicationComponent(LValueTypeData typeData,
ArgumentSource &&KeyPath)
: PhysicalPathComponent(typeData, KeyPathApplicationKind),
KeyPath(std::move(KeyPath))
{}
// An rvalue base object is passed indirectly +1 so needs to be
// materialized if the base we have is +0 or a loaded value.
void makeBaseConsumableMaterializedRValue(SILGenFunction &SGF,
SILLocation loc,
ManagedValue &base) {
if (base.isLValue()) {
auto tmp = SGF.emitTemporaryAllocation(loc, base.getType());
SGF.B.createCopyAddr(loc, base.getValue(), tmp,
IsNotTake, IsInitialization);
base = SGF.emitManagedBufferWithCleanup(tmp);
return;
}
bool isBorrowed = base.isPlusZeroRValueOrTrivial()
&& !base.getType().isTrivial(SGF.SGM.M);
if (!base.getType().isAddress() || isBorrowed) {
auto tmp = SGF.emitTemporaryAllocation(loc, base.getType());
if (isBorrowed)
base.copyInto(SGF, tmp, loc);
else
base.forwardInto(SGF, loc, tmp);
base = SGF.emitManagedBufferWithCleanup(tmp);
}
}
ManagedValue mutableOffset(
SILGenFunction &SGF, SILLocation loc, ManagedValue base) && {
auto &C = SGF.getASTContext();
auto keyPathTy = KeyPath.getSubstType()->castTo<BoundGenericType>();
FuncDecl *projectionFunction;
if (keyPathTy->getDecl() == C.getWritableKeyPathDecl()) {
// Turn the base lvalue into a pointer to pass to the projection
// function.
// This is OK since the materialized base is exclusive-borrowed for the
// duration of the access.
auto baseRawPtr = SGF.B.createAddressToPointer(loc,
base.getValue(),
SILType::getRawPointerType(SGF.getASTContext()));
auto basePtrTy = BoundGenericType::get(C.getUnsafeMutablePointerDecl(),
nullptr,
keyPathTy->getGenericArgs()[0])
->getCanonicalType();
auto basePtr = SGF.B.createStruct(loc,
SILType::getPrimitiveObjectType(basePtrTy),
SILValue(baseRawPtr));
base = ManagedValue::forUnmanaged(basePtr);
projectionFunction = C.getProjectKeyPathWritable(nullptr);
} else if (keyPathTy->getDecl() == C.getReferenceWritableKeyPathDecl()) {
projectionFunction = C.getProjectKeyPathReferenceWritable(nullptr);
makeBaseConsumableMaterializedRValue(SGF, loc, base);
} else {
llvm_unreachable("not a writable key path type?!");
}
auto projectionGenericSig = projectionFunction->getGenericSignature();
auto subMap = SubstitutionMap::get(
projectionGenericSig,
[&](SubstitutableType *type) -> Type {
auto genericParam = cast<GenericTypeParamType>(type);
auto index =
projectionGenericSig->getGenericParamOrdinal(genericParam);
return keyPathTy->getGenericArgs()[index];
},
LookUpConformanceInSignature(*projectionGenericSig));
// The projection function behaves like an owning addressor, returning
// a pointer to the projected value and an owner reference that keeps
// it alive.
auto keyPathValue = std::move(KeyPath).getAsSingleValue(SGF);
auto resultTuple = SGF.emitApplyOfLibraryIntrinsic(loc,
projectionFunction,
subMap,
{base, keyPathValue},
SGFContext());
SmallVector<ManagedValue, 2> members;
std::move(resultTuple).getAll(members);
auto projectedPtr = members[0];
auto projectedOwner = members[1];
// Pass along the projected pointer.
auto rawValueField = *C.getUnsafeMutablePointerDecl()
->getStoredProperties().begin();
auto projectedRawPtr = SGF.B.createStructExtract(loc,
projectedPtr.getUnmanagedValue(),
rawValueField,
SILType::getRawPointerType(C));
SILValue projectedAddr = SGF.B.createPointerToAddress(loc,
projectedRawPtr,
getTypeOfRValue().getAddressType(),
/*strict*/ true);
// Mark the projected address's dependence on the owner.
projectedAddr = SGF.B.createMarkDependence(loc, projectedAddr,
projectedOwner.getValue());
// Push a cleanup to destroy the owner object. We don't want to leave
// it to release whenever because the key path implementation hangs
// the writeback operations specific to the traversal onto the destruction
// of the owner.
struct DestroyOwnerPseudoComponent : WritebackPseudoComponent {
ManagedValue owner;
DestroyOwnerPseudoComponent(const LValueTypeData &typeData,
ManagedValue owner)
: WritebackPseudoComponent(typeData), owner(owner)
{}
void writeback(SILGenFunction &SGF, SILLocation loc,
ManagedValue base,
MaterializedLValue materialized,
bool isFinal) override {
SGF.Cleanups.popAndEmitCleanup(owner.getCleanup(),
CleanupLocation::get(loc),
NotForUnwind);
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS << "DestroyOwnerPseudoComponent";
}
};
std::unique_ptr<LogicalPathComponent> component(
new DestroyOwnerPseudoComponent(getTypeData(), projectedOwner));
pushWriteback(SGF, loc, std::move(component), base, MaterializedLValue());
return ManagedValue::forLValue(projectedAddr);
}
ManagedValue readOnlyOffset(
SILGenFunction &SGF, SILLocation loc, ManagedValue base) && {
auto &C = SGF.getASTContext();
makeBaseConsumableMaterializedRValue(SGF, loc, base);
auto keyPathValue = std::move(KeyPath).getAsSingleValue(SGF);
// Upcast the key path operand to the base KeyPath type, as expected by
// the read-only projection function.
BoundGenericType *keyPathTy
= keyPathValue.getType().castTo<BoundGenericType>();
if (keyPathTy->getDecl() != C.getKeyPathDecl()) {
keyPathTy = BoundGenericType::get(C.getKeyPathDecl(), Type(),
keyPathTy->getGenericArgs());
keyPathValue = SGF.B.createUpcast(loc, keyPathValue,
SILType::getPrimitiveObjectType(keyPathTy->getCanonicalType()));
}
auto projectFn = C.getProjectKeyPathReadOnly(nullptr);
auto projectionGenericSig = projectFn->getGenericSignature();
auto subMap = SubstitutionMap::get(
projectionGenericSig,
[&](SubstitutableType *type) -> Type {
auto genericParam = cast<GenericTypeParamType>(type);
auto index =
projectionGenericSig->getGenericParamOrdinal(genericParam);
return keyPathTy->getGenericArgs()[index];
},
LookUpConformanceInSignature(*projectionGenericSig));
// Allocate a temporary to own the projected value.
auto &resultTL = SGF.getTypeLowering(keyPathTy->getGenericArgs()[1]);
auto resultInit = SGF.emitTemporary(loc, resultTL);
auto result = SGF.emitApplyOfLibraryIntrinsic(loc, projectFn,
subMap, {base, keyPathValue}, SGFContext(resultInit.get()));
if (!result.isInContext())
std::move(result).forwardInto(SGF, loc, resultInit.get());
// Result should be a temporary we own. Return its address as an lvalue.
return ManagedValue::forLValue(resultInit->getAddress());
}
ManagedValue offset(SILGenFunction &SGF, SILLocation loc, ManagedValue base,
AccessKind accessKind) && override {
assert(SGF.InFormalEvaluationScope &&
"offsetting l-value for modification without writeback scope");
switch (accessKind) {
case AccessKind::ReadWrite:
case AccessKind::Write:
return std::move(*this).mutableOffset(SGF, loc, base);
case AccessKind::Read:
// For a read-only access, project the key path as if immutable,
// so that we don't trigger captured writebacks or observers or other
// operations that might be enqueued by a mutable projection.
return std::move(*this).readOnlyOffset(SGF, loc, base);
}
}
void dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "KeyPathApplicationComponent\n";
}
};
} // 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,
ArgumentSource &&valueSource,
ManagedValue base) && {
RValue value = std::move(valueSource).getAsRValue(SGF);
// 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)
{}
virtual bool isLoadingPure() const override { return true; }
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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "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)
{}
virtual bool isLoadingPure() const override { return true; }
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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "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) {
}
virtual bool isLoadingPure() const override { return true; }
AccessKind getBaseAccessKind(SILGenFunction &SGF,
AccessKind kind) const override {
// Always use the same access kind for the base.
return kind;
}
Optional<AccessedStorage> getAccessedStorage() const override {
return None;
}
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,
ArgumentSource &&valueSource, ManagedValue base) && override {
assert(base && "ownership component must not be root of lvalue path");
auto &TL = SGF.getTypeLowering(base.getType());
auto value = std::move(valueSource).getAsSingleValue(SGF).forward(SGF);
SGF.emitSemanticStore(loc, value, 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 dump(raw_ostream &OS, unsigned indent) const override {
OS.indent(indent) << "OwnershipComponent(...)\n";
}
};
} // end anonymous namespace
LValue LValue::forValue(ManagedValue value,
CanType substFormalType) {
if (value.getType().isObject()) {
LValueTypeData typeData = getValueTypeData(substFormalType,
value.getValue());
LValue lv;
lv.add<ValueComponent>(value, None, typeData, /*isRValue=*/true);
return lv;
} else {
// Treat an address-only value as an lvalue we only read from.
if (!value.isLValue())
value = ManagedValue::forLValue(value.getValue());
return forAddress(value, None, AbstractionPattern(substFormalType),
substFormalType);
}
}
LValue LValue::forAddress(ManagedValue address,
Optional<SILAccessEnforcement> enforcement,
AbstractionPattern origFormalType,
CanType substFormalType) {
assert(address.isLValue());
LValueTypeData typeData = {
origFormalType, substFormalType, address.getType().getObjectType()
};
LValue lv;
lv.add<ValueComponent>(address, enforcement, typeData);
return lv;
}
void LValue::addMemberComponent(SILGenFunction &SGF, SILLocation loc,
AbstractStorageDecl *storage,
SubstitutionMap subs,
LValueOptions options,
bool isSuper,
AccessStrategy accessStrategy,
CanType formalRValueType,
RValue &&indices,
Expr *indexExprForDiagnostics) {
if (auto var = dyn_cast<VarDecl>(storage)) {
assert(indices.isNull());
addMemberVarComponent(SGF, loc, var, subs, options, isSuper,
accessStrategy, formalRValueType);
} else {
auto subscript = cast<SubscriptDecl>(storage);
addMemberSubscriptComponent(SGF, loc, subscript, subs, options, isSuper,
accessStrategy, formalRValueType,
std::move(indices), indexExprForDiagnostics);
}
}
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 {
dump(llvm::errs());
}
void LValue::dump(raw_ostream &OS, unsigned indent) const {
for (const auto &component : *this) {
component->dump(OS, indent);
}
}
LValue SILGenFunction::emitLValue(Expr *e, AccessKind accessKind,
LValueOptions options) {
// Some lvalue nodes (namely BindOptionalExprs) require immediate evaluation
// of their subexpression, so we must have a writeback scope open while
// building an lvalue.
assert(InFormalEvaluationScope && "must be in a formal evaluation scope");
LValue r = SILGenLValue(*this).visit(e, accessKind, options);
// 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;
}
static LValue visitRecInOut(SILGenLValue &SGL, Expr *e, AccessKind accessKind,
LValueOptions options, AbstractionPattern orig) {
auto lv = SGL.visit(e, accessKind, options);
// If necessary, handle reabstraction with a SubstToOrigComponent that handles
// writeback in the original representation.
if (orig.isValid()) {
auto &origTL = SGL.SGF.getTypeLowering(orig, e->getType()->getRValueType());
if (lv.getTypeOfRValue() != origTL.getLoweredType().getObjectType())
lv.addSubstToOrigComponent(orig, origTL.getLoweredType().getObjectType());
}
return lv;
}
// Otherwise we have a non-lvalue type (references, values, metatypes,
// etc). These act as the root of a logical lvalue.
static ManagedValue visitRecNonInOutBase(SILGenLValue &SGL, Expr *e,
AccessKind accessKind,
LValueOptions options,
AbstractionPattern orig) {
auto &SGF = SGL.SGF;
// For an rvalue base, apply the reabstraction (if any) eagerly, since
// there's no need for writeback.
if (orig.isValid()) {
return SGF.emitRValueAsOrig(
e, orig, SGF.getTypeLowering(orig, e->getType()->getRValueType()));
}
// Ok, at this point we know that re-abstraction is not required.
SGFContext ctx;
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()->getFullName() == 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());
CanType formalRValueType = dre->getType()->getCanonicalType();
ManagedValue selfLValue =
SGF.emitAddressOfLocalVarDecl(dre, vd, formalRValueType,
AccessKind::Read);
selfLValue = SGF.emitFormalEvaluationRValueForSelfInDelegationInit(
e, formalRValueType,
selfLValue.getLValueAddress(), ctx)
.getAsSingleValue(SGF, e);
return selfLValue;
}
}
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 (SGF.SGM.Types.isIndirectPlusZeroSelfParameter(e->getType())) {
ctx = SGFContext::AllowGuaranteedPlusZero;
}
ManagedValue mv = SGF.emitRValueAsSingleValue(e, ctx);
if (mv.isPlusZeroRValueOrTrivial())
return mv;
// Any temporaries needed to materialize the lvalue must be destroyed when
// at the end of the lvalue's formal evaluation scope.
// e.g. for foo(self.bar)
// %self = load [copy] %ptr_self
// %rvalue = barGetter(%self)
// destroy_value %self // self must be released before calling foo.
// foo(%rvalue)
SILValue value = mv.forward(SGF);
return SGF.emitFormalAccessManagedRValueWithCleanup(CleanupLocation(e),
value);
}
LValue SILGenLValue::visitRec(Expr *e, AccessKind accessKind,
LValueOptions options, AbstractionPattern orig) {
// First see if we have an lvalue type. If we do, then quickly handle that and
// return.
if (e->getType()->is<LValueType>() || e->isSemanticallyInOutExpr()) {
return visitRecInOut(*this, e, accessKind, options, orig);
}
// Otherwise we have a non-lvalue type (references, values, metatypes,
// etc). These act as the root of a logical lvalue. Compute the root value,
// wrap it in a ValueComponent, and return it for our caller.
ManagedValue rv = visitRecNonInOutBase(*this, e, accessKind, options, orig);
CanType formalType = getSubstFormalRValueType(e);
auto typeData = getValueTypeData(formalType, rv.getValue());
LValue lv;
lv.add<ValueComponent>(rv, None, typeData, /*isRValue=*/true);
return lv;
}
LValue SILGenLValue::visitExpr(Expr *e, AccessKind accessKind,
LValueOptions options) {
e->dump(llvm::errs());
llvm_unreachable("unimplemented lvalue expr");
}
namespace {
/// A CRTP class for emitting accesses.
template <class Impl, class StorageType>
struct AccessEmitter {
SILGenFunction &SGF;
StorageType *Storage;
CanType FormalRValueType;
Impl &asImpl() { return static_cast<Impl&>(*this); }
AccessEmitter(SILGenFunction &SGF, StorageType *storage,
CanType formalRValueType)
: SGF(SGF), Storage(storage), FormalRValueType(formalRValueType) {}
void emitUsingStrategy(AccessStrategy strategy) {
switch (strategy.getKind()) {
case AccessStrategy::Storage: {
auto typeData =
getPhysicalStorageTypeData(SGF.SGM, Storage, FormalRValueType);
return asImpl().emitUsingStorage(typeData);
}
case AccessStrategy::BehaviorStorage:
return asImpl().emitUsingBehaviorStorage();
case AccessStrategy::DirectToAccessor:
return asImpl().emitUsingAccessor(strategy.getAccessor(), true);
case AccessStrategy::DispatchToAccessor:
return asImpl().emitUsingAccessor(strategy.getAccessor(), false);
case AccessStrategy::MaterializeToTemporary: {
auto typeData = getLogicalStorageTypeData(SGF.SGM, FormalRValueType);
return asImpl().emitUsingMaterialization(strategy.getReadStrategy(),
strategy.getWriteStrategy(),
typeData);
}
}
llvm_unreachable("unknown kind");
}
void emitUsingAccessor(AccessorKind accessorKind, bool isDirect) {
switch (accessorKind) {
case AccessorKind::Get:
case AccessorKind::Set:
case AccessorKind::MaterializeForSet: {
auto accessor =
accessorKind == AccessorKind::Get ?
SGF.SGM.getGetterDeclRef(Storage) :
accessorKind == AccessorKind::Set ?
SGF.SGM.getSetterDeclRef(Storage) :
SGF.SGM.getMaterializeForSetDeclRef(Storage);
auto typeData = getLogicalStorageTypeData(SGF.SGM, FormalRValueType);
return asImpl().emitUsingGetterSetter(accessor, isDirect, typeData);
}
case AccessorKind::Address:
case AccessorKind::MutableAddress: {
auto accessor =
accessorKind == AccessorKind::Address
? SGF.SGM.getAddressorDeclRef(Storage)
: SGF.SGM.getMutableAddressorDeclRef(Storage);
auto typeData =
getPhysicalStorageTypeData(SGF.SGM, Storage, FormalRValueType);
return asImpl().emitUsingAddressor(accessor, isDirect, typeData);
}
case AccessorKind::Read:
case AccessorKind::Modify: {
auto accessor =
accessorKind == AccessorKind::Read
? SGF.SGM.getReadCoroutineDeclRef(Storage)
: SGF.SGM.getModifyCoroutineDeclRef(Storage);
auto typeData =
getPhysicalStorageTypeData(SGF.SGM, Storage, FormalRValueType);
return asImpl().emitUsingCoroutineAccessor(accessor, isDirect,
typeData);
}
case AccessorKind::WillSet:
case AccessorKind::DidSet:
llvm_unreachable("cannot use accessor directly to perform an access");
}
llvm_unreachable("bad kind");
}
};
}
SubstitutionMap
SILGenModule::getNonMemberVarDeclSubstitutions(VarDecl *var) {
auto *dc = var->getDeclContext();
if (auto *genericEnv = dc->getGenericEnvironmentOfContext())
return genericEnv->getForwardingSubstitutionMap();
return SubstitutionMap();
}
static LValue emitLValueForNonMemberVarDecl(SILGenFunction &SGF,
SILLocation loc, VarDecl *var,
CanType formalRValueType,
AccessKind accessKind,
LValueOptions options,
AccessSemantics semantics) {
LValue lv;
auto strategy = var->getAccessStrategy(semantics, accessKind, SGF.FunctionDC);
lv.addNonMemberVarComponent(SGF, loc, var, /*be lazy*/ None,
options, strategy, formalRValueType);
return lv;
}
void LValue::addNonMemberVarComponent(SILGenFunction &SGF, SILLocation loc,
VarDecl *var,
Optional<SubstitutionMap> subs,
LValueOptions options,
AccessStrategy strategy,
CanType formalRValueType) {
struct NonMemberVarAccessEmitter :
AccessEmitter<NonMemberVarAccessEmitter, VarDecl> {
LValue &LV;
SILLocation Loc;
Optional<SubstitutionMap> Subs;
LValueOptions Options;
SubstitutionMap getSubs() {
if (Subs) return *Subs;
Subs = SGF.SGM.getNonMemberVarDeclSubstitutions(Storage);
return *Subs;
}
NonMemberVarAccessEmitter(SILGenFunction &SGF, SILLocation loc,
VarDecl *var, Optional<SubstitutionMap> subs,
CanType formalRValueType,
LValueOptions options, LValue &lv)
: AccessEmitter(SGF, var, formalRValueType),
LV(lv), Loc(loc), Subs(subs), Options(options) {}
void emitUsingAddressor(SILDeclRef addressor, bool isDirect,
LValueTypeData typeData) {
SILType storageType =
SGF.SGM.Types.getLoweredType(Storage->getType()).getAddressType();
LV.add<AddressorComponent>(Storage, addressor,
/*isSuper=*/false, isDirect, getSubs(),
CanType(), typeData, storageType);
}
void emitUsingCoroutineAccessor(SILDeclRef accessor, bool isDirect,
LValueTypeData typeData) {
LV.add<CoroutineAccessorComponent>(Storage, accessor,
/*isSuper*/ false, isDirect, getSubs(),
CanType(), typeData);
}
void emitUsingGetterSetter(SILDeclRef accessor, bool isDirect,
LValueTypeData typeData) {
LV.add<GetterSetterComponent>(Storage, accessor,
/*isSuper=*/false, isDirect, getSubs(),
CanType(), typeData);
}
void emitUsingMaterialization(AccessStrategy readStrategy,
AccessStrategy writeStrategy,
LValueTypeData typeData) {
LV.add<MaterializeToTemporaryComponent>(Storage, /*super*/false,
getSubs(), Options,
readStrategy, writeStrategy,
/*base type*/CanType(), typeData,
nullptr, nullptr);
}
void emitUsingStorage(LValueTypeData typeData) {
// If it's a physical value (e.g. a local variable in memory), push its
// address.
// Check for a local (possibly captured) variable.
auto address = SGF.maybeEmitValueOfLocalVarDecl(Storage);
// The only other case that should get here is a global variable.
if (!address) {
address = SGF.emitGlobalVariableRef(Loc, Storage);
}
assert(address.isLValue() &&
"physical lvalue decl ref must evaluate to an address");
Optional<SILAccessEnforcement> enforcement;
if (!Storage->isLet()) {
if (Options.IsNonAccessing) {
enforcement = None;
} else if (Storage->getDeclContext()->isLocalContext()) {
enforcement = SGF.getUnknownEnforcement(Storage);
} else if (Storage->getDeclContext()->isModuleScopeContext()) {
enforcement = SGF.getDynamicEnforcement(Storage);
} else {
assert(Storage->getDeclContext()->isTypeContext() &&
!Storage->isInstanceMember());
enforcement = SGF.getDynamicEnforcement(Storage);
}
}
LV.add<ValueComponent>(address, enforcement, typeData);
if (address.getType().is<ReferenceStorageType>())
LV.add<OwnershipComponent>(typeData);
}
void emitUsingBehaviorStorage() {
// TODO: Behaviors aren't supported for non-instance properties yet.
llvm_unreachable("not implemented");
}
} emitter(SGF, loc, var, subs, formalRValueType, options, *this);
emitter.emitUsingStrategy(strategy);
}
ManagedValue
SILGenFunction::maybeEmitValueOfLocalVarDecl(VarDecl *var) {
// For local decls, use the address we allocated or the value if we have it.
auto It = VarLocs.find(var);
if (It != VarLocs.end()) {
// If this has an address, return it. By-value let's have no address.
SILValue ptr = It->second.value;
if (ptr->getType().isAddress())
return ManagedValue::forLValue(ptr);
// Otherwise, it is an RValue let. Uses of it are borrows, but we don't
// want to proactively emit a borrow here.
// TODO: integrate this with how callers want these values so we can do
// something more semantic than just forUnmanaged.
return ManagedValue::forUnmanaged(ptr);
}
// Otherwise, it's non-local or not stored.
return ManagedValue();
}
ManagedValue
SILGenFunction::emitAddressOfLocalVarDecl(SILLocation loc, VarDecl *var,
CanType formalRValueType,
AccessKind accessKind) {
assert(var->getDeclContext()->isLocalContext());
assert(var->getImplInfo().isSimpleStored());
auto address = maybeEmitValueOfLocalVarDecl(var);
assert(address);
assert(address.isLValue());
return address;
}
RValue SILGenFunction::emitRValueForNonMemberVarDecl(SILLocation loc,
VarDecl *var,
CanType formalRValueType,
AccessSemantics semantics,
SGFContext C) {
// Any writebacks for this access are tightly scoped.
FormalEvaluationScope scope(*this);
auto localValue = maybeEmitValueOfLocalVarDecl(var);
// If this VarDecl is represented as an address, emit it as an lvalue, then
// perform a load to get the rvalue.
if (localValue && localValue.isLValue()) {
bool guaranteedValid = false;
IsTake_t shouldTake = IsNotTake;
// We should only end up in this path for local and global variables,
// i.e. ones whose lifetime is assured for the duration of the evaluation.
// Therefore, if the variable is a constant, the value is guaranteed
// valid as well.
if (var->isLet())
guaranteedValid = true;
// Protect the lvalue read with access markers. The !is<LValueType> assert
// above ensures that the "LValue" is actually immutable, so we use an
// unenforced access marker.
SILValue destAddr = localValue.getLValueAddress();
SILValue accessAddr = UnenforcedFormalAccess::enter(*this, loc, destAddr,
SILAccessKind::Read);
auto propagateRValuePastAccess = [&](RValue &&rvalue) {
// Check if a new begin_access was emitted and returned as the
// RValue. This means that the load did not actually load. If so, then
// fix the rvalue to begin_access operand. The end_access cleanup
// doesn't change. FIXME: this can't happen with sil-opaque-values.
if (accessAddr != destAddr && rvalue.isComplete()
&& rvalue.isPlusZero(*this) && !isa<TupleType>(rvalue.getType())) {
auto mv = std::move(rvalue).getScalarValue();
if (mv.getValue() == accessAddr)
mv = std::move(mv).transform(
cast<BeginAccessInst>(accessAddr)->getOperand());
return RValue(*this, loc, formalRValueType, mv);
}
return std::move(rvalue);
};
// If we have self, see if we are in an 'init' delegation sequence. If so,
// call out to the special delegation init routine. Otherwise, use the
// normal RValue emission logic.
if (var->getName() == getASTContext().Id_self &&
SelfInitDelegationState != NormalSelf) {
auto rvalue =
emitRValueForSelfInDelegationInit(loc, formalRValueType, accessAddr, C);
return propagateRValuePastAccess(std::move(rvalue));
}
// Avoid computing an abstraction pattern for local variables.
// This is a slight compile-time optimization, but more importantly
// it avoids problems where locals don't always have interface types.
if (var->getDeclContext()->isLocalContext()) {
auto &rvalueTL = getTypeLowering(formalRValueType);
auto rvalue = RValue(*this, loc, formalRValueType,
emitLoad(loc, accessAddr, rvalueTL,
C, shouldTake, guaranteedValid));
return propagateRValuePastAccess(std::move(rvalue));
}
// Otherwise, do the full thing where we potentially bridge and
// reabstract the declaration.
auto origFormalType = SGM.Types.getAbstractionPattern(var);
auto rvalue = RValue(*this, loc, formalRValueType,
emitLoad(loc, accessAddr, origFormalType,
formalRValueType,
getTypeLowering(formalRValueType),
C, shouldTake, guaranteedValid));
return propagateRValuePastAccess(std::move(rvalue));
}
// For local decls, use the address we allocated or the value if we have it.
if (localValue) {
// Mutable lvalue and address-only 'let's are LValues.
assert(!localValue.getType().isAddress() &&
"LValue cases should be handled above");
SILValue Scalar = localValue.getUnmanagedValue();
// For weak and unowned types, convert the reference to the right
// pointer.
if (Scalar->getType().is<ReferenceStorageType>()) {
Scalar = emitConversionToSemanticRValue(loc, Scalar,
getTypeLowering(formalRValueType));
// emitConversionToSemanticRValue always produces a +1 strong result.
return RValue(*this, loc, formalRValueType,
emitManagedRValueWithCleanup(Scalar));
}
// This is a let, so we can make guarantees, so begin the borrow scope.
ManagedValue Result = emitManagedBeginBorrow(loc, Scalar);
// If the client can't handle a +0 result, retain it to get a +1.
// This is a 'let', so we can make guarantees.
return RValue(*this, loc, formalRValueType,
C.isGuaranteedPlusZeroOk()
? Result : Result.copyUnmanaged(*this, loc));
}
LValue lv = emitLValueForNonMemberVarDecl(*this, loc, var, formalRValueType,
AccessKind::Read, LValueOptions(),
semantics);
return emitLoadOfLValue(loc, std::move(lv), C);
}
LValue SILGenLValue::visitDiscardAssignmentExpr(DiscardAssignmentExpr *e,
AccessKind accessKind,
LValueOptions options) {
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),
None, typeData);
return lv;
}
LValue SILGenLValue::visitDeclRefExpr(DeclRefExpr *e, AccessKind accessKind,
LValueOptions options) {
// The only non-member decl that can be an lvalue is VarDecl.
return emitLValueForNonMemberVarDecl(SGF, e, cast<VarDecl>(e->getDecl()),
getSubstFormalRValueType(e),
accessKind, options,
e->getAccessSemantics());
}
LValue SILGenLValue::visitOpaqueValueExpr(OpaqueValueExpr *e,
AccessKind accessKind,
LValueOptions options) {
// Handle an opaque lvalue that refers to an opened existential.
auto known = SGF.OpaqueValueExprs.find(e);
if (known != SGF.OpaqueValueExprs.end()) {
// Dig the open-existential expression out of the list.
OpenExistentialExpr *opened = known->second;
SGF.OpaqueValueExprs.erase(known);
// Do formal evaluation of the underlying existential lvalue.
auto lv = visitRec(opened->getExistentialValue(), accessKind, options);
lv = SGF.emitOpenExistentialLValue(
opened, std::move(lv),
CanArchetypeType(opened->getOpenedArchetype()),
e->getType()->getWithoutSpecifierType()->getCanonicalType(),
accessKind);
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), None,
getValueTypeData(SGF, e));
return lv;
}
LValue SILGenLValue::visitDotSyntaxBaseIgnoredExpr(DotSyntaxBaseIgnoredExpr *e,
AccessKind accessKind,
LValueOptions options) {
SGF.emitIgnoredExpr(e->getLHS());
return visitRec(e->getRHS(), accessKind, options);
}
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.getKind()) {
// Assume that the member only partially projects the enclosing value.
case AccessStrategy::Storage:
return (accessKind == AccessKind::Read
? AccessKind::Read : AccessKind::ReadWrite);
case AccessStrategy::MaterializeToTemporary: {
assert(accessKind == AccessKind::ReadWrite);
auto writeBaseKind = getBaseAccessKind(member, AccessKind::Write,
strategy.getWriteStrategy());
// Fast path for the common case that the write will need to mutate
// the base.
if (writeBaseKind == AccessKind::ReadWrite)
return writeBaseKind;
auto readBaseKind = getBaseAccessKind(member, AccessKind::Read,
strategy.getReadStrategy());
return combineAccessKinds(readBaseKind, writeBaseKind);
}
case AccessStrategy::DirectToAccessor:
case AccessStrategy::DispatchToAccessor:
return getBaseAccessKindForAccessor(
member->getAccessor(strategy.getAccessor()));
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,
LValueOptions options) {
// 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, SGF.FunctionDC);
LValue lv = visitRec(e->getBase(),
getBaseAccessKind(var, accessKind, strategy),
getBaseOptions(options, strategy));
assert(lv.isValid());
CanType substFormalRValueType = getSubstFormalRValueType(e);
lv.addMemberVarComponent(SGF, e, var,
e->getMember().getSubstitutions(),
options, e->isSuper(),
strategy, substFormalRValueType);
return lv;
}
namespace {
/// A CRTP class for emitting member accesses.
template <class Impl, class StorageType>
struct MemberStorageAccessEmitter : AccessEmitter<Impl, StorageType> {
using super = AccessEmitter<Impl, StorageType>;
using super::SGF;
using super::Storage;
using super::FormalRValueType;
LValue &LV;
LValueOptions Options;
SILLocation Loc;
bool IsSuper;
CanType BaseFormalType;
SubstitutionMap Subs;
Expr *IndexExprForDiagnostics;
RValue *Indices;
MemberStorageAccessEmitter(SILGenFunction &SGF, SILLocation loc,
StorageType *storage,
SubstitutionMap subs,
bool isSuper,
CanType formalRValueType,
LValueOptions options,
LValue &lv,
Expr *indexExprForDiagnostics,
RValue *indices)
: super(SGF, storage, formalRValueType),
LV(lv), Options(options), Loc(loc), IsSuper(isSuper),
BaseFormalType(lv.getSubstFormalType()), Subs(subs),
IndexExprForDiagnostics(indexExprForDiagnostics), Indices(indices) {}
void emitUsingAddressor(SILDeclRef addressor, bool isDirect,
LValueTypeData typeData) {
SILType varStorageType =
SGF.SGM.Types.getSubstitutedStorageType(Storage, FormalRValueType);
LV.add<AddressorComponent>(Storage, addressor, IsSuper, isDirect, Subs,
BaseFormalType, typeData, varStorageType,
IndexExprForDiagnostics, Indices);
}
void emitUsingCoroutineAccessor(SILDeclRef accessor, bool isDirect,
LValueTypeData typeData) {
LV.add<CoroutineAccessorComponent>(Storage, accessor, IsSuper, isDirect,
Subs, BaseFormalType, typeData,
IndexExprForDiagnostics, Indices);
}
void emitUsingGetterSetter(SILDeclRef accessor, bool isDirect,
LValueTypeData typeData) {
LV.add<GetterSetterComponent>(Storage, accessor, IsSuper, isDirect,
Subs, BaseFormalType, typeData,
IndexExprForDiagnostics, Indices);
}
void emitUsingMaterialization(AccessStrategy readStrategy,
AccessStrategy writeStrategy,
LValueTypeData typeData) {
LV.add<MaterializeToTemporaryComponent>(Storage, IsSuper, Subs, Options,
readStrategy, writeStrategy,
BaseFormalType, typeData,
IndexExprForDiagnostics, Indices);
}
};
} // end anonymous namespace
void LValue::addMemberVarComponent(SILGenFunction &SGF, SILLocation loc,
VarDecl *var,
SubstitutionMap subs,
LValueOptions options,
bool isSuper,
AccessStrategy strategy,
CanType formalRValueType) {
struct MemberVarAccessEmitter
: MemberStorageAccessEmitter<MemberVarAccessEmitter, VarDecl> {
using MemberStorageAccessEmitter::MemberStorageAccessEmitter;
void emitUsingStorage(LValueTypeData typeData) {
// 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 (Storage->isStatic()) {
// FIXME: this implicitly drops the earlier components, but maybe
// we ought to evaluate them for side-effects even during the
// formal access?
LV.Path.clear();
LV.addNonMemberVarComponent(SGF, Loc, Storage, Subs, Options,
AccessStrategy::getStorage(),
FormalRValueType);
return;
}
// Otherwise, it's a physical member.
SILType varStorageType =
SGF.SGM.Types.getSubstitutedStorageType(Storage, FormalRValueType);
if (BaseFormalType->mayHaveSuperclass()) {
LV.add<RefElementComponent>(Storage, Options, varStorageType, typeData);
} else {
assert(BaseFormalType->getStructOrBoundGenericStruct());
LV.add<StructElementComponent>(Storage, varStorageType, typeData);
}
// If the member has weak or unowned storage, convert it away.
if (varStorageType.is<ReferenceStorageType>()) {
LV.add<OwnershipComponent>(typeData);
}
}
// For behavior initializations, we should have set up a marking proxy that
// replaces the access path.
void emitUsingBehaviorStorage() {
auto addr = SGF.maybeEmitValueOfLocalVarDecl(Storage);
assert(addr && addr.isLValue());
LV = LValue();
auto typeData =
getPhysicalStorageTypeData(SGF.SGM, Storage, FormalRValueType);
LV.add<ValueComponent>(addr, None, typeData);
}
} emitter(SGF, loc, var, subs, isSuper, formalRValueType, options, *this,
/*indices for diags*/ nullptr, /*indices*/ nullptr);
emitter.emitUsingStrategy(strategy);
}
LValue SILGenLValue::visitSubscriptExpr(SubscriptExpr *e,
AccessKind accessKind,
LValueOptions options) {
auto decl = cast<SubscriptDecl>(e->getDecl().getDecl());
auto accessSemantics = e->getAccessSemantics();
auto strategy =
decl->getAccessStrategy(accessSemantics, accessKind, SGF.FunctionDC);
LValue lv = visitRec(e->getBase(),
getBaseAccessKind(decl, accessKind, strategy),
getBaseOptions(options, 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(),
options, e->isSuper(), strategy,
formalRValueType, std::move(index),
indexExpr);
return lv;
}
LValue SILGenLValue::visitKeyPathApplicationExpr(KeyPathApplicationExpr *e,
AccessKind accessKind,
LValueOptions options) {
// Determine the base access strategy based on the strategy of this access.
auto keyPathTy = e->getKeyPath()->getType()->castTo<BoundGenericType>();
AccessKind subAccess;
if (keyPathTy->getDecl() == SGF.getASTContext().getWritableKeyPathDecl()) {
// Assume the keypath only partially projects the root value.
subAccess = (accessKind == AccessKind::Read
? AccessKind::Read : AccessKind::ReadWrite);
} else {
// The base is only ever read from a read-only or reference-writable
// keypath.
subAccess = AccessKind::Read;
}
// For now, just ignore any options we were given.
LValueOptions subOptions = LValueOptions();
// The base should be reabstracted to the maximal abstraction pattern.
LValue lv = visitRec(e->getBase(), subAccess, subOptions,
AbstractionPattern::getOpaque());
// The result will end up projected at the maximal abstraction level too.
auto resultTy = e->getType()->getRValueType()->getCanonicalType();
auto resultSILTy = SGF.getLoweredType(AbstractionPattern::getOpaque(),
resultTy);
lv.add<KeyPathApplicationComponent>(
LValueTypeData(AbstractionPattern::getOpaque(), resultTy,
resultSILTy.getObjectType()),
ArgumentSource(e->getKeyPath()));
// Reabstract to the substituted abstraction level if necessary.
auto substResultSILTy = SGF.getLoweredType(resultTy);
if (resultSILTy.getObjectType() != substResultSILTy.getObjectType()) {
lv.addOrigToSubstComponent(substResultSILTy);
}
return lv;
}
void LValue::addMemberSubscriptComponent(SILGenFunction &SGF, SILLocation loc,
SubscriptDecl *decl,
SubstitutionMap subs,
LValueOptions options,
bool isSuper,
AccessStrategy strategy,
CanType formalRValueType,
RValue &&indices,
Expr *indexExprForDiagnostics) {
struct MemberSubscriptAccessEmitter
: MemberStorageAccessEmitter<MemberSubscriptAccessEmitter,
SubscriptDecl> {
using MemberStorageAccessEmitter::MemberStorageAccessEmitter;
void emitUsingStorage(LValueTypeData typeData) {
llvm_unreachable("subscripts never have storage");
}
void emitUsingBehaviorStorage() {
llvm_unreachable("subscripts never have behaviors");
}
} emitter(SGF, loc, decl, subs, isSuper, formalRValueType, options, *this,
indexExprForDiagnostics, &indices);
emitter.emitUsingStrategy(strategy);
}
bool LValue::isObviouslyNonConflicting(const LValue &other,
AccessKind selfAccess,
AccessKind otherAccess) {
// Reads never conflict with reads.
if (selfAccess == AccessKind::Read && otherAccess == AccessKind::Read)
return true;
// We can cover more cases here.
return false;
}
LValue SILGenLValue::visitTupleElementExpr(TupleElementExpr *e,
AccessKind accessKind,
LValueOptions options) {
unsigned index = e->getFieldNumber();
LValue lv = visitRec(e->getBase(),
accessKind == AccessKind::Read
? AccessKind::Read : AccessKind::ReadWrite,
options.forProjectedBaseLValue());
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,
LValueOptions options) {
// 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,
options);
});
}
// Record the fact that we're opening this existential. The actual
// opening operation will occur when we see the OpaqueValueExpr.
bool inserted = SGF.OpaqueValueExprs.insert({e->getOpaqueValue(), e}).second;
(void)inserted;
assert(inserted && "already have this opened existential?");
// Visit the subexpression.
LValue lv = visitRec(e->getSubExpr(), accessKind, options);
// Sanity check that we did see the OpaqueValueExpr.
assert(SGF.OpaqueValueExprs.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.getOptionalObjectType(),
baseTypeData.SubstFormalType.getOptionalObjectType(),
baseTypeData.TypeOfRValue.getEnumElementType(someDecl, SGF.SGM.M),
};
}
LValue SILGenLValue::visitForceValueExpr(ForceValueExpr *e,
AccessKind accessKind,
LValueOptions options) {
// Like BindOptional, this is a read even if we only write to the result.
// (But it's unnecessary to use a force this way!)
LValue lv = visitRec(e->getSubExpr(),
combineAccessKinds(accessKind, AccessKind::Read),
options.forComputedBaseLValue());
LValueTypeData typeData = getOptionalObjectTypeData(SGF, lv.getTypeData());
bool isImplicitUnwrap = e->isImplicit() &&
e->isForceOfImplicitlyUnwrappedOptional();
lv.add<ForceOptionalObjectComponent>(typeData, isImplicitUnwrap);
return lv;
}
LValue SILGenLValue::visitBindOptionalExpr(BindOptionalExpr *e,
AccessKind accessKind,
LValueOptions options) {
// Binding reads the base even if we then only write to the result.
accessKind = combineAccessKinds(accessKind, AccessKind::Read);
// Do formal evaluation of the base l-value.
LValue optLV = visitRec(e->getSubExpr(), accessKind,
options.forComputedBaseLValue());
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.emitBindOptionalAddress(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, None, valueTypeData);
return valueLV;
}
LValue SILGenLValue::visitInOutExpr(InOutExpr *e, AccessKind accessKind,
LValueOptions options) {
return visitRec(e->getSubExpr(), accessKind, options);
}
/// 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,
LValueOptions options,
AccessKind accessKind,
AccessSemantics semantics) {
SILGenLValue sgl(*this);
LValue lv;
auto baseType = base.getType().getASTType();
auto subMap = baseType->getContextSubstitutionMap(
SGM.M.getSwiftModule(), ivar->getDeclContext());
LValueTypeData baseTypeData = getValueTypeData(baseFormalType,
base.getValue());
// Refer to 'self' as the base of the lvalue.
lv.add<ValueComponent>(base, None, baseTypeData,
/*isRValue=*/!base.isLValue());
auto substFormalType = ivar->getInterfaceType().subst(subMap)
->getCanonicalType().getReferenceStorageReferent();
AccessStrategy strategy =
ivar->getAccessStrategy(semantics, accessKind, FunctionDC);
lv.addMemberVarComponent(*this, loc, ivar, subMap, options, /*super*/ false,
strategy, substFormalType);
return lv;
}
// This is emitLoad that will handle re-abstraction and bridging for the client.
ManagedValue SILGenFunction::emitLoad(SILLocation loc, SILValue addr,
AbstractionPattern origFormalType,
CanType substFormalType,
const TypeLowering &rvalueTL,
SGFContext C, IsTake_t isTake,
bool isAddressGuaranteed) {
assert(addr->getType().isAddress());
SILType addrRValueType = addr->getType().getReferenceStorageReferentType();
// Fast path: the types match exactly.
if (addrRValueType == rvalueTL.getLoweredType().getAddressType()) {
return emitLoad(loc, addr, rvalueTL, C, isTake, isAddressGuaranteed);
}
// Otherwise, we need to reabstract or bridge.
auto conversion =
origFormalType.isClangType()
? Conversion::getBridging(Conversion::BridgeFromObjC,
origFormalType.getType(),
substFormalType, rvalueTL.getLoweredType())
: Conversion::getOrigToSubst(origFormalType, substFormalType);
return emitConvertedRValue(loc, conversion, C,
[&](SILGenFunction &SGF, SILLocation loc, SGFContext C) {
return SGF.emitLoad(loc, addr, getTypeLowering(addrRValueType),
C, isTake, isAddressGuaranteed);
});
}
/// Load an r-value out of the given address.
///
/// \param rvalueTL - the type lowering for the type-of-rvalue
/// of the address
/// \param isAddrGuaranteed - 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 isAddrGuaranteed) {
// 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 &&
(isAddrGuaranteed ? 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 isAddressGuaranteed - 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 isAddressGuaranteed) {
// 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 && (isAddressGuaranteed ? 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) {
auto storageType = src->getType();
auto swiftStorageType = storageType.castTo<ReferenceStorageType>();
switch (swiftStorageType->getOwnership()) {
case ReferenceOwnership::Strong:
llvm_unreachable("strong reference storage type should be impossible");
#define NEVER_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
/* Address-only storage types are handled with their underlying type. */ \
llvm_unreachable("address-only pointers are handled elsewhere");
#define ALWAYS_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
return B.createCopy##Name##Value(loc, src);
#define SOMETIMES_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For loadable reference storage types, we need to generate a strong */ \
/* retain and strip the box. */ \
assert(storageType.castTo<Name##StorageType>()->isLoadable( \
ResilienceExpansion::Maximal)); \
return B.createCopy##Name##Value(loc, src); \
}
#define UNCHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For static reference storage types, we need to strip the box and */ \
/* then do an (unsafe) retain. */ \
auto type = storageType.castTo<Name##StorageType>(); \
auto result = B.create##Name##ToRef(loc, src, \
SILType::getPrimitiveObjectType(type.getReferentType())); \
/* SEMANTIC ARC TODO: Does this need a cleanup? */ \
return B.createCopyValue(loc, result); \
}
#include "swift/AST/ReferenceStorage.def"
}
llvm_unreachable("impossible");
}
ManagedValue SILGenFunction::emitConversionToSemanticRValue(
SILLocation loc, ManagedValue src, const TypeLowering &valueTL) {
auto swiftStorageType = src.getType().castTo<ReferenceStorageType>();
switch (swiftStorageType->getOwnership()) {
case ReferenceOwnership::Strong:
llvm_unreachable("strong reference storage type should be impossible");
#define NEVER_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
/* Address-only storage types are handled with their underlying type. */ \
llvm_unreachable("address-only pointers are handled elsewhere");
#define ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
/* Generate a strong retain and strip the box. */ \
return B.createCopy##Name##Value(loc, src);
#define UNCHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
/* Strip the box and then do an (unsafe) retain. */ \
return B.createUnsafeCopy##Name##Value(loc, src);
#include "swift/AST/ReferenceStorage.def"
}
llvm_unreachable("impossible");
}
/// 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) {
auto storageType = src->getType();
auto swiftStorageType = storageType.castTo<ReferenceStorageType>();
switch (swiftStorageType->getOwnership()) {
case ReferenceOwnership::Strong:
llvm_unreachable("strong reference storage type should be impossible");
#define NEVER_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
return SGF.B.createLoad##Name(loc, src, isTake);
#define ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name) \
{ \
/* For loadable types, we need to strip the box. */ \
/* If we are not performing a take, use a load_borrow. */ \
if (!isTake) { \
SILValue value = SGF.B.createLoadBorrow(loc, src); \
SILValue strongValue = SGF.B.createCopy##Name##Value(loc, value); \
SGF.B.createEndBorrow(loc, value, src); \
return strongValue; \
} \
/* Otherwise perform a load take and destroy the stored value. */ \
auto value = SGF.B.emitLoadValueOperation(loc, src, \
LoadOwnershipQualifier::Take); \
SILValue strongValue = SGF.B.createCopy##Name##Value(loc, value); \
SGF.B.createDestroyValue(loc, value); \
return strongValue; \
}
#define ALWAYS_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name)
#define SOMETIMES_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For loadable types, we need to strip the box. */ \
auto type = storageType.castTo<Name##StorageType>(); \
if (!type->isLoadable(ResilienceExpansion::Maximal)) { \
return SGF.B.createLoad##Name(loc, src, isTake); \
} \
ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name) \
}
#define UNCHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For static reference storage types, we need to strip the box. */ \
auto type = storageType.castTo<Name##StorageType>(); \
auto value = SGF.B.createLoad(loc, src, LoadOwnershipQualifier::Trivial); \
auto result = SGF.B.create##Name##ToRef(loc, value, \
SILType::getPrimitiveObjectType(type.getReferentType())); \
/* SEMANTIC ARC TODO: Does this need a cleanup? */ \
return SGF.B.createCopyValue(loc, result); \
}
#include "swift/AST/ReferenceStorage.def"
#undef ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER
}
}
/// 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();
auto swiftStorageType = storageType.castTo<ReferenceStorageType>();
switch (swiftStorageType->getOwnership()) {
case ReferenceOwnership::Strong:
llvm_unreachable("strong reference storage type should be impossible");
#define NEVER_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
SGF.B.createStore##Name(loc, value, dest, isInit); \
/* store doesn't take ownership of the input, so cancel it out. */ \
SGF.B.emitDestroyValueOperation(loc, value); \
return; \
}
#define ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name) \
{ \
auto typedValue = SGF.B.createRefTo##Name(loc, value, \
storageType.getObjectType()); \
auto copiedVal = SGF.B.createCopyValue(loc, typedValue); \
emitUnloweredStoreOfCopy(SGF.B, loc, copiedVal, dest, isInit); \
SGF.B.emitDestroyValueOperation(loc, value); \
return; \
}
#define ALWAYS_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name)
#define SOMETIMES_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For loadable types, we need to enter the box by */ \
/* turning the strong retain into an type-specific retain. */ \
auto type = storageType.castTo<Name##StorageType>(); \
/* FIXME: resilience */ \
if (!type->isLoadable(ResilienceExpansion::Maximal)) { \
SGF.B.createStore##Name(loc, value, dest, isInit); \
/* store doesn't take ownership of the input, so cancel it out. */ \
SGF.B.emitDestroyValueOperation(loc, value); \
return; \
} \
ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER(Name) \
}
#define UNCHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For static reference storage types, we need to enter the box and */ \
/* release the strong retain. */ \
auto typedValue = SGF.B.createRefTo##Name(loc, value, \
storageType.getObjectType()); \
emitUnloweredStoreOfCopy(SGF.B, loc, typedValue, dest, isInit); \
SGF.B.emitDestroyValueOperation(loc, value); \
return; \
}
#include "swift/AST/ReferenceStorage.def"
#undef ALWAYS_OR_SOMETIMES_LOADABLE_CHECKED_REF_STORAGE_HELPER
}
llvm_unreachable("impossible");
}
/// 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;
}
auto swiftStorageType = storageType.castTo<ReferenceStorageType>();
switch (swiftStorageType->getOwnership()) {
case ReferenceOwnership::Strong:
llvm_unreachable("strong reference storage type should be impossible");
#define NEVER_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: \
llvm_unreachable("address-only types are never loadable");
#define ALWAYS_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
SILValue value = B.createRefTo##Name(loc, semanticValue, storageType); \
value = B.createCopyValue(loc, value); \
B.emitDestroyValueOperation(loc, semanticValue); \
return value; \
}
#define SOMETIMES_LOADABLE_CHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For loadable types, place into a box. */ \
auto type = storageType.castTo<Name##StorageType>(); \
assert(type->isLoadable(ResilienceExpansion::Maximal)); \
(void) type; \
SILValue value = B.createRefTo##Name(loc, semanticValue, storageType); \
value = B.createCopyValue(loc, value); \
B.emitDestroyValueOperation(loc, semanticValue); \
return value; \
}
#define UNCHECKED_REF_STORAGE(Name, ...) \
case ReferenceOwnership::Name: { \
/* For static reference storage types, place into a box. */ \
SILValue value = B.createRefTo##Name(loc, semanticValue, storageType); \
B.emitDestroyValueOperation(loc, semanticValue); \
return value; \
}
#include "swift/AST/ReferenceStorage.def"
}
llvm_unreachable("impossible");
}
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) {
bool isRValue = component.isRValue();
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().Sanitizers & SanitizerKind::Thread) &&
tsanKind == TSanKind::InoutAccess && !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));
}
static ArgumentSource emitBaseValueForAccessor(SILGenFunction &SGF,
SILLocation loc, LValue &&lvalue,
CanType baseFormalType,
SILDeclRef accessor) {
auto decl = cast<FuncDecl>(accessor.getDecl());
auto finalAccessKind = getBaseAccessKindForAccessor(decl);
ManagedValue base;
PathComponent &&component =
drillToLastComponent(SGF, loc, std::move(lvalue), base, finalAccessKind);
base = drillIntoComponent(SGF, loc, std::move(component), base,
finalAccessKind, TSanKind::None);
return SGF.prepareAccessorBaseArg(loc, base, baseFormalType, accessor);
}
RValue SILGenFunction::emitLoadOfLValue(SILLocation loc, LValue &&src,
SGFContext C, bool isBaseGuaranteed) {
// Any writebacks should be scoped to after the load.
FormalEvaluationScope scope(*this);
// We shouldn't need to re-abstract here, but we might have to bridge.
// This should only happen if we have a global variable of NSString type.
auto origFormalType = src.getOrigFormalType();
auto substFormalType = src.getSubstFormalType();
auto &rvalueTL = getTypeLowering(src.getTypeOfRValue());
ManagedValue addr;
PathComponent &&component =
drillToLastComponent(*this, loc, std::move(src), addr, AccessKind::Read);
// If the last component is physical, drill down and load from it.
if (component.isPhysical()) {
addr = std::move(component.asPhysical())
.offset(*this, loc, addr, AccessKind::Read);
return RValue(*this, loc, substFormalType,
emitLoad(loc, addr.getValue(),
origFormalType, substFormalType,
rvalueTL, C, IsNotTake,
isBaseGuaranteed));
}
// If the last component is logical, 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());
}
LValue
SILGenFunction::emitOpenExistentialLValue(SILLocation loc,
LValue &&lv,
CanArchetypeType openedArchetype,
CanType formalRValueType,
AccessKind accessKind) {
assert(!formalRValueType->hasLValueType());
LValueTypeData typeData = {
AbstractionPattern::getOpaque(), formalRValueType,
getLoweredType(formalRValueType).getObjectType()
};
// Open up the existential.
auto rep = lv.getTypeOfRValue()
.getPreferredExistentialRepresentation(SGM.M);
switch (rep) {
case ExistentialRepresentation::Opaque:
case ExistentialRepresentation::Boxed: {
lv.add<OpenOpaqueExistentialComponent>(openedArchetype, typeData);
break;
}
case ExistentialRepresentation::Metatype:
case ExistentialRepresentation::Class: {
lv.add<OpenNonOpaqueExistentialComponent>(openedArchetype, typeData);
break;
}
case ExistentialRepresentation::None:
llvm_unreachable("cannot open non-existential");
}
return std::move(lv);
}
static bool trySetterPeephole(SILGenFunction &SGF, SILLocation loc,
ArgumentSource &&src, LValue &&dest) {
// The last component must be a getter/setter.
// TODO: allow reabstraction here, too.
auto &component = **(dest.end() - 1);
if (component.getKind() != PathComponent::GetterSetterKind)
return false;
// We cannot apply the peephole if the l-value includes an
// open-existential component because we need to make sure that
// the opened archetype is available everywhere during emission.
// TODO: should we instead just immediately open the existential
// during emitLValue and simply leave the opened address in the LValue?
// Or is there some reasonable way to detect that this is happening
// and avoid affecting cases where it is not necessary?
for (auto &componentPtr : dest) {
if (componentPtr->isOpenExistential())
return false;
}
auto &setterComponent = static_cast<GetterSetterComponent&>(component);
setterComponent.emitAssignWithSetter(SGF, loc, std::move(dest),
std::move(src));
return true;;
}
void SILGenFunction::emitAssignToLValue(SILLocation loc, RValue &&src,
LValue &&dest) {
emitAssignToLValue(loc, ArgumentSource(loc, std::move(src)), std::move(dest));
}
void SILGenFunction::emitAssignToLValue(SILLocation loc,
ArgumentSource &&src,
LValue &&dest) {
FormalEvaluationScope scope(*this);
// If the last component is a getter/setter component, use a special
// generation pattern that allows us to peephole the emission of the RHS.
if (trySetterPeephole(*this, loc, std::move(src), std::move(dest)))
return;
// Otherwise, force the RHS now to preserve evaluation order.
auto srcLoc = src.getLocation();
RValue srcValue = std::move(src).getAsRValue(*this);
// Peephole: instead of materializing and then assigning into a
// translation component, untransform the value first.
while (dest.isLastComponentTranslation()) {
srcValue = std::move(dest.getLastTranslationComponent())
.untranslate(*this, loc, std::move(srcValue));
dest.dropLastTranslationComponent();
}
src = ArgumentSource(srcLoc, std::move(srcValue));
// 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);
auto value = std::move(src).getAsRValue(*this).ensurePlusOne(*this, loc);
std::move(value).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();
if (!dest->canPerformInPlaceInitialization())
return skipPeephole();
auto destAddr = dest->getAddressForInPlaceInitialization(*this, loc);
assert(src.getTypeOfRValue().getASTType()
== destAddr->getType().getASTType());
auto srcAddr = emitAddressOfLValue(loc, std::move(src), AccessKind::Read)
.getUnmanagedValue();
UnenforcedAccess access;
SILValue accessAddress =
access.beginAccess(*this, loc, destAddr, SILAccessKind::Modify);
B.createCopyAddr(loc, srcAddr, accessAddress, IsNotTake, IsInitialization);
access.endAccess(*this);
dest->finishInitialization(*this);
}
void SILGenFunction::emitAssignLValueToLValue(SILLocation loc, LValue &&src,
LValue &&dest) {
// Only perform the peephole if both operands are physical, there's no
// semantic conversion necessary, and exclusivity enforcement
// is not enabled. The peephole interferes with exclusivity enforcement
// because it causes the formal accesses to the source and destination to
// overlap.
bool peepholeConflict =
!src.isObviouslyNonConflicting(dest, AccessKind::Read, AccessKind::Write);
if (peepholeConflict || !src.isPhysical() || !dest.isPhysical()) {
RValue loaded = emitLoadOfLValue(loc, std::move(src), SGFContext());
emitAssignToLValue(loc, std::move(loaded), std::move(dest));
return;
}
auto &rvalueTL = getTypeLowering(src.getTypeOfRValue());
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, rvalueTL, SGFContext(), IsNotTake);
loaded.assignInto(*this, loc, destAddr);
}
}