Files
swift-mirror/lib/AST/LifetimeDependence.cpp
Andrew Trick 50ee84a0b4 Infer LifetimeDependenceInfo on a mutating method
We need this at least until we have 'dependsOn(self)' syntax.

When 'self' is nonescapable and the result is 'void', assume that 'self' depends
on a single nonescapable argument.
2024-07-30 15:57:57 -07:00

712 lines
26 KiB
C++

//===--- LifetimeDependence.cpp -----------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2024 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
//
//===----------------------------------------------------------------------===//
#include "swift/AST/LifetimeDependence.h"
#include "swift/AST/ASTContext.h"
#include "swift/AST/Decl.h"
#include "swift/AST/DiagnosticsSema.h"
#include "swift/AST/Module.h"
#include "swift/AST/ParameterList.h"
#include "swift/AST/Type.h"
#include "swift/AST/TypeRepr.h"
#include "swift/Basic/Assertions.h"
#include "swift/Basic/Defer.h"
#include "swift/Basic/Range.h"
namespace swift {
std::optional<LifetimeDependenceInfo>
getLifetimeDependenceFor(ArrayRef<LifetimeDependenceInfo> lifetimeDependencies,
unsigned index) {
for (auto dep : lifetimeDependencies) {
if (dep.getTargetIndex() == index) {
return dep;
}
}
return std::nullopt;
}
std::string LifetimeDependenceInfo::getString() const {
std::string lifetimeDependenceString;
auto getOnIndices = [](IndexSubset *bitvector) {
std::string result;
bool isFirstSetBit = true;
for (unsigned i = 0; i < bitvector->getCapacity(); i++) {
if (bitvector->contains(i)) {
if (!isFirstSetBit) {
result += ", ";
}
result += std::to_string(i);
isFirstSetBit = false;
}
}
return result;
};
if (inheritLifetimeParamIndices && !inheritLifetimeParamIndices->isEmpty()) {
lifetimeDependenceString =
"_inherit(" + getOnIndices(inheritLifetimeParamIndices) + ") ";
}
if (scopeLifetimeParamIndices && !scopeLifetimeParamIndices->isEmpty()) {
lifetimeDependenceString +=
"_scope(" + getOnIndices(scopeLifetimeParamIndices) + ") ";
}
return lifetimeDependenceString;
}
void LifetimeDependenceInfo::Profile(llvm::FoldingSetNodeID &ID) const {
if (inheritLifetimeParamIndices) {
ID.AddInteger((uint8_t)LifetimeDependenceKind::Inherit);
inheritLifetimeParamIndices->Profile(ID);
}
if (scopeLifetimeParamIndices) {
ID.AddInteger((uint8_t)LifetimeDependenceKind::Scope);
scopeLifetimeParamIndices->Profile(ID);
}
}
static LifetimeDependenceKind
getLifetimeDependenceKindFromType(Type sourceType) {
if (sourceType->isEscapable()) {
return LifetimeDependenceKind::Scope;
}
return LifetimeDependenceKind::Inherit;
}
// Warning: this is incorrect for Setter 'newValue' parameters. It should only
// be called for a Setter's 'self'.
static ValueOwnership getLoweredOwnership(AbstractFunctionDecl *afd) {
if (isa<ConstructorDecl>(afd)) {
return ValueOwnership::Owned;
}
if (auto *ad = dyn_cast<AccessorDecl>(afd)) {
if (ad->getAccessorKind() == AccessorKind::Set ||
ad->getAccessorKind() == AccessorKind::Modify) {
return ValueOwnership::InOut;
}
}
return ValueOwnership::Shared;
}
static bool
isLifetimeDependenceCompatibleWithOwnership(LifetimeDependenceKind kind,
ValueOwnership ownership,
AbstractFunctionDecl *afd) {
if (kind == LifetimeDependenceKind::Inherit) {
return true;
}
assert(kind == LifetimeDependenceKind::Scope);
auto loweredOwnership = ownership != ValueOwnership::Default
? ownership
: getLoweredOwnership(afd);
if (loweredOwnership == ValueOwnership::InOut ||
loweredOwnership == ValueOwnership::Shared) {
return true;
}
assert(loweredOwnership == ValueOwnership::Owned);
return false;
}
LifetimeDependenceInfo
LifetimeDependenceInfo::getForIndex(AbstractFunctionDecl *afd,
unsigned targetIndex, unsigned sourceIndex,
LifetimeDependenceKind kind) {
auto *dc = afd->getDeclContext();
auto &ctx = dc->getASTContext();
unsigned capacity = afd->hasImplicitSelfDecl()
? (afd->getParameters()->size() + 1)
: afd->getParameters()->size();
auto indexSubset = IndexSubset::get(ctx, capacity, {sourceIndex});
if (kind == LifetimeDependenceKind::Scope) {
return LifetimeDependenceInfo{/*inheritLifetimeParamIndices*/ nullptr,
/*scopeLifetimeParamIndices*/ indexSubset,
targetIndex,
/*isImmortal*/ false};
}
return LifetimeDependenceInfo{/*inheritLifetimeParamIndices*/ indexSubset,
/*scopeLifetimeParamIndices*/ nullptr,
targetIndex,
/*isImmortal*/ false};
}
void LifetimeDependenceInfo::getConcatenatedData(
SmallVectorImpl<bool> &concatenatedData) const {
auto pushData = [&](IndexSubset *paramIndices) {
if (paramIndices == nullptr) {
return;
}
assert(!paramIndices->isEmpty());
for (unsigned i = 0; i < paramIndices->getCapacity(); i++) {
if (paramIndices->contains(i)) {
concatenatedData.push_back(true);
continue;
}
concatenatedData.push_back(false);
}
};
if (hasInheritLifetimeParamIndices()) {
pushData(inheritLifetimeParamIndices);
}
if (hasScopeLifetimeParamIndices()) {
pushData(scopeLifetimeParamIndices);
}
}
static Type getResultOrYield(AbstractFunctionDecl *afd) {
if (auto *accessor = dyn_cast<AccessorDecl>(afd)) {
if (accessor->isCoroutine()) {
auto yieldTyInContext = accessor->mapTypeIntoContext(
accessor->getStorage()->getValueInterfaceType());
return yieldTyInContext;
}
}
Type resultType;
if (auto fn = dyn_cast<FuncDecl>(afd)) {
resultType = fn->getResultInterfaceType();
} else {
auto ctor = cast<ConstructorDecl>(afd);
resultType = ctor->getResultInterfaceType();
}
return afd->mapTypeIntoContext(resultType);
}
static bool hasEscapableResultOrYield(AbstractFunctionDecl *afd) {
return getResultOrYield(afd)->isEscapable();
}
static LifetimeDependenceKind getLifetimeDependenceKindFromDecl(
ParsedLifetimeDependenceKind parsedLifetimeDependenceKind, Type paramType) {
if (parsedLifetimeDependenceKind == ParsedLifetimeDependenceKind::Scope) {
return LifetimeDependenceKind::Scope;
}
if (parsedLifetimeDependenceKind == ParsedLifetimeDependenceKind::Inherit) {
// TODO: assert that this can happen in SIL tests
return LifetimeDependenceKind::Inherit;
}
return paramType->isEscapable() ? LifetimeDependenceKind::Scope
: LifetimeDependenceKind::Inherit;
}
static bool isBitwiseCopyable(Type type, ASTContext &ctx) {
auto *bitwiseCopyableProtocol =
ctx.getProtocol(KnownProtocolKind::BitwiseCopyable);
if (!bitwiseCopyableProtocol) {
return false;
}
return (bool)(ModuleDecl::checkConformance(type, bitwiseCopyableProtocol));
}
std::optional<LifetimeDependenceInfo> LifetimeDependenceInfo::fromTypeRepr(
AbstractFunctionDecl *afd, LifetimeDependentTypeRepr *lifetimeDependentRepr,
unsigned targetIndex) {
auto *dc = afd->getDeclContext();
auto &ctx = dc->getASTContext();
auto &diags = ctx.Diags;
auto capacity = afd->hasImplicitSelfDecl()
? (afd->getParameters()->size() + 1)
: afd->getParameters()->size();
SmallBitVector inheritLifetimeParamIndices(capacity);
SmallBitVector scopeLifetimeParamIndices(capacity);
auto updateLifetimeDependenceInfo = [&](LifetimeDependenceSpecifier specifier,
unsigned paramIndexToSet,
Type paramType,
ValueOwnership ownership) {
auto loc = specifier.getLoc();
auto parsedLifetimeKind = specifier.getParsedLifetimeDependenceKind();
auto lifetimeKind =
getLifetimeDependenceKindFromDecl(parsedLifetimeKind, paramType);
bool isCompatible = true;
// Lifetime dependence always propagates through temporary BitwiseCopyable
// values, even if the dependence is scoped.
if (!isBitwiseCopyable(paramType, ctx)) {
isCompatible = isLifetimeDependenceCompatibleWithOwnership(
lifetimeKind, ownership, afd);
}
if (parsedLifetimeKind == ParsedLifetimeDependenceKind::Scope &&
!isCompatible) {
diags.diagnose(
loc, diag::lifetime_dependence_cannot_use_parsed_scoped_consuming);
return true;
}
if (!isCompatible) {
assert(lifetimeKind == LifetimeDependenceKind::Scope);
diags.diagnose(
loc, diag::lifetime_dependence_cannot_use_inferred_scoped_consuming);
return true;
}
if (inheritLifetimeParamIndices.test(paramIndexToSet) ||
scopeLifetimeParamIndices.test(paramIndexToSet)) {
diags.diagnose(loc, diag::lifetime_dependence_duplicate_param_id);
return true;
}
if (lifetimeKind == LifetimeDependenceKind::Inherit) {
inheritLifetimeParamIndices.set(paramIndexToSet);
} else {
assert(lifetimeKind == LifetimeDependenceKind::Scope);
scopeLifetimeParamIndices.set(paramIndexToSet);
}
return false;
};
for (auto specifier : lifetimeDependentRepr->getLifetimeDependencies()) {
switch (specifier.getSpecifierKind()) {
case LifetimeDependenceSpecifier::SpecifierKind::Immortal: {
auto immortalParam =
std::find_if(afd->getParameters()->begin(), afd->getParameters()->end(), [](ParamDecl *param) {
return strcmp(param->getName().get(), "immortal") == 0;
});
if (immortalParam != afd->getParameters()->end()) {
diags.diagnose(*immortalParam,
diag::lifetime_dependence_immortal_conflict_name);
}
return LifetimeDependenceInfo(nullptr, nullptr, targetIndex,
/*isImmortal*/ true);
}
case LifetimeDependenceSpecifier::SpecifierKind::Named: {
bool foundParamName = false;
unsigned paramIndex = 0;
for (auto *param : *afd->getParameters()) {
if (param->getParameterName() == specifier.getName()) {
if (updateLifetimeDependenceInfo(
specifier, paramIndex,
afd->mapTypeIntoContext(
param->toFunctionParam().getParameterType()),
param->getValueOwnership())) {
return std::nullopt;
}
foundParamName = true;
break;
}
paramIndex++;
}
if (!foundParamName) {
diags.diagnose(specifier.getLoc(),
diag::lifetime_dependence_invalid_param_name,
specifier.getName());
return std::nullopt;
}
break;
}
case LifetimeDependenceSpecifier::SpecifierKind::Ordered: {
auto index = specifier.getIndex();
if (index >= afd->getParameters()->size()) {
diags.diagnose(specifier.getLoc(),
diag::lifetime_dependence_invalid_param_index, index);
return std::nullopt;
}
auto param = afd->getParameters()->get(index);
auto ownership = param->getValueOwnership();
auto type =
afd->mapTypeIntoContext(param->toFunctionParam().getParameterType());
if (updateLifetimeDependenceInfo(specifier, index, type, ownership)) {
return std::nullopt;
}
break;
}
case LifetimeDependenceSpecifier::SpecifierKind::Self: {
if (!afd->hasImplicitSelfDecl()) {
diags.diagnose(specifier.getLoc(),
diag::lifetime_dependence_invalid_self_in_static);
return std::nullopt;
}
if (isa<ConstructorDecl>(afd)) {
diags.diagnose(specifier.getLoc(),
diag::lifetime_dependence_invalid_self_in_init);
return std::nullopt;
}
if (updateLifetimeDependenceInfo(
specifier, /* selfIndex */ afd->getParameters()->size(),
afd->getImplicitSelfDecl()->getTypeInContext(),
afd->getImplicitSelfDecl()->getValueOwnership())) {
return std::nullopt;
}
break;
}
}
}
return LifetimeDependenceInfo(
inheritLifetimeParamIndices.any()
? IndexSubset::get(ctx, inheritLifetimeParamIndices)
: nullptr,
scopeLifetimeParamIndices.any()
? IndexSubset::get(ctx, scopeLifetimeParamIndices)
: nullptr,
targetIndex,
/*isImmortal*/ false);
}
// This utility is similar to its overloaded version that builds the
// LifetimeDependenceInfo from the swift decl. Reason for duplicated code is the
// apis on type and ownership is different in SIL compared to Sema.
std::optional<LifetimeDependenceInfo> LifetimeDependenceInfo::fromTypeRepr(
LifetimeDependentTypeRepr *lifetimeDependentRepr, unsigned targetIndex,
ArrayRef<SILParameterInfo> params, DeclContext *dc) {
auto &ctx = dc->getASTContext();
auto &diags = ctx.Diags;
auto capacity = params.size(); // SIL parameters include self
SmallBitVector inheritLifetimeParamIndices(capacity);
SmallBitVector scopeLifetimeParamIndices(capacity);
auto updateLifetimeDependenceInfo = [&](LifetimeDependenceSpecifier specifier,
unsigned paramIndexToSet,
ParameterConvention paramConvention) {
auto loc = specifier.getLoc();
auto kind = specifier.getParsedLifetimeDependenceKind();
if (kind == ParsedLifetimeDependenceKind::Scope &&
(!isGuaranteedParameterInCallee(paramConvention) &&
!isMutatingParameter(paramConvention))) {
diags.diagnose(loc, diag::lifetime_dependence_cannot_use_kind, "_scope",
getStringForParameterConvention(paramConvention));
return true;
}
if (inheritLifetimeParamIndices.test(paramIndexToSet) ||
scopeLifetimeParamIndices.test(paramIndexToSet)) {
diags.diagnose(loc, diag::lifetime_dependence_duplicate_param_id);
return true;
}
if (kind == ParsedLifetimeDependenceKind::Inherit) {
inheritLifetimeParamIndices.set(paramIndexToSet);
} else {
assert(kind == ParsedLifetimeDependenceKind::Scope);
scopeLifetimeParamIndices.set(paramIndexToSet);
}
return false;
};
for (auto specifier : lifetimeDependentRepr->getLifetimeDependencies()) {
switch (specifier.getSpecifierKind()) {
case LifetimeDependenceSpecifier::SpecifierKind::Ordered: {
auto index = specifier.getIndex();
if (index > capacity) {
diags.diagnose(specifier.getLoc(),
diag::lifetime_dependence_invalid_param_index, index);
return std::nullopt;
}
auto param = params[index];
auto paramConvention = param.getConvention();
if (updateLifetimeDependenceInfo(specifier, index, paramConvention)) {
return std::nullopt;
}
break;
}
case LifetimeDependenceSpecifier::SpecifierKind::Immortal: {
return LifetimeDependenceInfo(/*inheritLifetimeParamIndices*/ nullptr,
/*scopeLifetimeParamIndices*/ nullptr,
targetIndex,
/*isImmortal*/ true);
}
default:
llvm_unreachable("SIL can only have ordered or immortal lifetime "
"dependence specifier kind");
}
}
return LifetimeDependenceInfo(
inheritLifetimeParamIndices.any()
? IndexSubset::get(ctx, inheritLifetimeParamIndices)
: nullptr,
scopeLifetimeParamIndices.any()
? IndexSubset::get(ctx, scopeLifetimeParamIndices)
: nullptr,
targetIndex,
/*isImmortal*/ false);
}
std::optional<LifetimeDependenceInfo>
LifetimeDependenceInfo::infer(AbstractFunctionDecl *afd) {
auto *dc = afd->getDeclContext();
auto &ctx = dc->getASTContext();
// Disable inference if requested.
if (!ctx.LangOpts.EnableExperimentalLifetimeDependenceInference) {
return std::nullopt;
}
// Setters infer 'self' dependence on 'newValue'.
if (auto accessor = dyn_cast<AccessorDecl>(afd)) {
if (accessor->getAccessorKind() == AccessorKind::Set) {
return inferSetter(accessor);
}
} else if (auto *fd = dyn_cast<FuncDecl>(afd)) {
// Infer self dependence for a mutating function with no result.
//
// FIXME: temporary hack until we have dependsOn(self: param) syntax.
// Do not apply this to accessors (_modify). _modify is handled below like a
// mutating method.
if (fd->isMutating() && fd->getResultInterfaceType()->isVoid()
&& !dc->getSelfTypeInContext()->isEscapable()) {
return inferMutatingSelf(afd);
}
}
if (hasEscapableResultOrYield(afd)) {
return std::nullopt;
}
if (afd->getAttrs().hasAttribute<UnsafeNonEscapableResultAttr>()) {
return std::nullopt;
}
auto &diags = ctx.Diags;
auto returnTypeRepr = afd->getResultTypeRepr();
auto returnLoc = returnTypeRepr ? returnTypeRepr->getLoc() : afd->getLoc();
unsigned resultIndex = afd->hasImplicitSelfDecl()
? afd->getParameters()->size() + 1
: afd->getParameters()->size();
auto *cd = dyn_cast<ConstructorDecl>(afd);
if (cd && cd->isImplicit()) {
if (cd->getParameters()->size() == 0) {
return std::nullopt;
}
}
if (!cd && afd->hasImplicitSelfDecl()) {
Type selfTypeInContext = dc->getSelfTypeInContext();
if (selfTypeInContext->isEscapable()) {
if (isBitwiseCopyable(selfTypeInContext, ctx)) {
diags.diagnose(
returnLoc,
diag::lifetime_dependence_method_escapable_bitwisecopyable_self);
return std::nullopt;
}
}
auto kind = getLifetimeDependenceKindFromType(selfTypeInContext);
auto selfOwnership = afd->getImplicitSelfDecl()->getValueOwnership();
if (!isLifetimeDependenceCompatibleWithOwnership(kind, selfOwnership,
afd)) {
diags.diagnose(returnLoc,
diag::lifetime_dependence_invalid_self_ownership);
return std::nullopt;
}
// Infer method dependence: result depends on self.
//
// This includes _modify. A _modify's yielded value depends on self. The
// caller of the _modify ensures that the 'self' depends on any value stored
// to the yielded address.
return LifetimeDependenceInfo::getForIndex(
afd, resultIndex, /*selfIndex */ afd->getParameters()->size(), kind);
}
std::optional<unsigned> candidateParamIndex;
std::optional<LifetimeDependenceKind> candidateLifetimeKind;
unsigned paramIndex = 0;
bool hasParamError = false;
for (auto *param : *afd->getParameters()) {
SWIFT_DEFER { paramIndex++; };
Type paramTypeInContext =
afd->mapTypeIntoContext(param->getInterfaceType());
if (paramTypeInContext->hasError()) {
hasParamError = true;
continue;
}
auto paramOwnership = param->getValueOwnership();
if (paramTypeInContext->isEscapable()) {
if (isBitwiseCopyable(paramTypeInContext, ctx)) {
continue;
}
if (paramOwnership == ValueOwnership::Default) {
continue;
}
}
candidateLifetimeKind =
getLifetimeDependenceKindFromType(paramTypeInContext);
if (!isLifetimeDependenceCompatibleWithOwnership(*candidateLifetimeKind,
paramOwnership, afd)) {
continue;
}
if (candidateParamIndex) {
if (cd && afd->isImplicit()) {
diags.diagnose(
returnLoc,
diag::lifetime_dependence_cannot_infer_ambiguous_candidate,
"on implicit initializer");
return std::nullopt;
}
diags.diagnose(returnLoc,
diag::lifetime_dependence_cannot_infer_ambiguous_candidate,
"");
return std::nullopt;
}
candidateParamIndex = paramIndex;
}
if (!candidateParamIndex && !hasParamError) {
if (cd && afd->isImplicit()) {
diags.diagnose(returnLoc,
diag::lifetime_dependence_cannot_infer_no_candidates,
" on implicit initializer");
return std::nullopt;
}
diags.diagnose(returnLoc,
diag::lifetime_dependence_cannot_infer_no_candidates, "");
return std::nullopt;
}
return LifetimeDependenceInfo::getForIndex(
afd, resultIndex, *candidateParamIndex, *candidateLifetimeKind);
}
/// Infer LifetimeDependence on a setter where 'self' is nonescapable.
std::optional<LifetimeDependenceInfo> LifetimeDependenceInfo::inferSetter(
AbstractFunctionDecl *afd) {
auto *param = afd->getParameters()->get(0);
Type paramTypeInContext =
afd->mapTypeIntoContext(param->getInterfaceType());
if (paramTypeInContext->hasError()) {
return std::nullopt;
}
if (paramTypeInContext->isEscapable()) {
return std::nullopt;
}
auto kind = getLifetimeDependenceKindFromType(paramTypeInContext);
return LifetimeDependenceInfo::getForIndex(
afd, /*selfIndex */ afd->getParameters()->size(), 0, kind);
}
/// Infer LifetimeDependenceInfo on a mutating method where 'self' is
/// nonescapable and the result is 'void'. For now, we'll assume that 'self'
/// depends on a single nonescapable argument.
std::optional<LifetimeDependenceInfo> LifetimeDependenceInfo::inferMutatingSelf(
AbstractFunctionDecl *afd) {
std::optional<LifetimeDependenceInfo> dep;
for (unsigned paramIndex : range(afd->getParameters()->size())) {
auto *param = afd->getParameters()->get(paramIndex);
Type paramTypeInContext =
afd->mapTypeIntoContext(param->getInterfaceType());
if (paramTypeInContext->hasError()) {
continue;
}
if (paramTypeInContext->isEscapable()) {
continue;
}
if (dep) {
// Don't infer dependence on multiple nonescapable parameters. We may want
// to do this in the future if dependsOn(self: arg1, arg2) syntax is too
// cumbersome.
return std::nullopt;
}
int selfIndex = afd->getParameters()->size();
dep = LifetimeDependenceInfo::getForIndex(
afd, selfIndex, paramIndex, LifetimeDependenceKind::Inherit);
}
return dep;
}
std::optional<llvm::ArrayRef<LifetimeDependenceInfo>>
LifetimeDependenceInfo::get(AbstractFunctionDecl *afd) {
if (!afd->getASTContext().LangOpts.hasFeature(Feature::NonescapableTypes)) {
return std::nullopt;
}
assert(isa<FuncDecl>(afd) || isa<ConstructorDecl>(afd));
SmallVector<LifetimeDependenceInfo> lifetimeDependencies;
auto &diags = afd->getASTContext().Diags;
auto getExplicitLifetimeDependence =
[&](TypeRepr *typeRepr, unsigned targetIndex,
Type targetType) -> std::optional<LifetimeDependenceInfo> {
auto *lifetimeTypeRepr =
dyn_cast_or_null<LifetimeDependentTypeRepr>(typeRepr);
if (!lifetimeTypeRepr) {
return std::nullopt;
}
if (targetType->isEscapable()) {
diags.diagnose(lifetimeTypeRepr->getLoc(),
diag::lifetime_dependence_invalid_type);
return std::nullopt;
}
return LifetimeDependenceInfo::fromTypeRepr(afd, lifetimeTypeRepr,
targetIndex);
};
auto getExplicitOrImplicitLifetimeDependence =
[&](TypeRepr *typeRepr, unsigned targetIndex,
Type targetType) -> std::optional<LifetimeDependenceInfo> {
if (isa_and_nonnull<LifetimeDependentTypeRepr>(typeRepr)) {
return getExplicitLifetimeDependence(typeRepr, targetIndex, targetType);
}
return LifetimeDependenceInfo::infer(afd);
};
for (unsigned targetIndex : indices(*afd->getParameters())) {
auto *param = (*afd->getParameters())[targetIndex];
auto paramType =
afd->mapTypeIntoContext(param->toFunctionParam().getParameterType());
if (auto result = getExplicitLifetimeDependence(param->getTypeRepr(),
targetIndex, paramType)) {
lifetimeDependencies.push_back(*result);
}
}
auto result = getExplicitOrImplicitLifetimeDependence(
afd->getResultTypeRepr(),
afd->hasImplicitSelfDecl() ? afd->getParameters()->size() + 1
: afd->getParameters()->size(),
getResultOrYield(afd));
if (result) {
lifetimeDependencies.push_back(*result);
}
return afd->getASTContext().AllocateCopy(lifetimeDependencies);
}
std::optional<llvm::ArrayRef<LifetimeDependenceInfo>>
LifetimeDependenceInfo::get(FunctionTypeRepr *funcRepr,
ArrayRef<SILParameterInfo> params,
ArrayRef<SILResultInfo> results, DeclContext *dc) {
if (!dc->getASTContext().LangOpts.hasFeature(Feature::NonescapableTypes)) {
return std::nullopt;
}
SmallVector<LifetimeDependenceInfo, 1> lifetimeDependencies;
auto getExplicitLifetimeDependence =
[&](TypeRepr *typeRepr,
unsigned targetIndex) -> std::optional<LifetimeDependenceInfo> {
auto *lifetimeTypeRepr =
dyn_cast_or_null<LifetimeDependentTypeRepr>(typeRepr);
if (!lifetimeTypeRepr) {
return std::nullopt;
}
return LifetimeDependenceInfo::fromTypeRepr(lifetimeTypeRepr, targetIndex,
params, dc);
};
auto argsTypeRepr = funcRepr->getArgsTypeRepr()->getElements();
for (unsigned targetIndex : indices(argsTypeRepr)) {
if (auto result = getExplicitLifetimeDependence(
argsTypeRepr[targetIndex].Type, targetIndex)) {
lifetimeDependencies.push_back(*result);
}
}
auto result = getExplicitLifetimeDependence(funcRepr->getResultTypeRepr(),
params.size());
if (result) {
lifetimeDependencies.push_back(*result);
}
return dc->getASTContext().AllocateCopy(lifetimeDependencies);
}
} // namespace swift