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Add a temporary @_nonEscapable attribute
For testing compiler support until we have the ~Escapable syntax.
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13 files changed

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‎docs/ReferenceGuides/UnderscoredAttributes.md

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@@ -625,6 +625,15 @@ This is the default behavior, unless the type annotated is an aggregate that
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consists entirely of `@_eagerMove` or trivial values, in which case the
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attribute overrides the inferred type-level annotation.
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## `@_nonEscapable`
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Indicates that a type is non-escapable. All instances of this type are
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non-escaping values. A non-escaping value's lifetime must be confined
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to another "parent" lifetime.
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This is temporary until ~Escapable syntax is supported, which will
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also work as a generic type constraint.
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## `@_marker`
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Indicates that a protocol is a marker protocol. Marker protocols represent some

‎include/swift/AST/Attr.def

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@@ -423,6 +423,9 @@ DECL_ATTR(_rawLayout, RawLayout,
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DECL_ATTR(_extern, Extern,
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OnFunc | ABIStableToAdd | ABIBreakingToRemove | APIStableToAdd | APIStableToRemove,
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147)
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SIMPLE_DECL_ATTR(_nonEscapable, NonEscapable,
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OnNominalType | UserInaccessible | ABIBreakingToAdd | ABIStableToRemove | APIBreakingToAdd | APIStableToRemove,
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148)
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CONTEXTUAL_SIMPLE_DECL_ATTR(final, Final,
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OnClass | OnFunc | OnAccessor | OnVar | OnSubscript | DeclModifier | ABIBreakingToAdd | ABIBreakingToRemove | APIStableToAdd | APIStableToRemove,
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2)

‎include/swift/AST/Decl.h

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@@ -2611,13 +2611,20 @@ class ValueDecl : public Decl {
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/// Whether this declaration can not be copied and thus is move only.
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unsigned isMoveOnly : 1;
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/// Whether the "isEscapable" bit has been computed yet.
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unsigned isEscapable : 1;
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/// Whether this declaration is escapable.
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unsigned isEscapableComputed : 1;
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} LazySemanticInfo = { };
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friend class DynamicallyReplacedDeclRequest;
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friend class OverriddenDeclsRequest;
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friend class IsObjCRequest;
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friend class IsFinalRequest;
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friend class IsMoveOnlyRequest;
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friend class IsEscapableRequest;
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friend class IsDynamicRequest;
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friend class IsImplicitlyUnwrappedOptionalRequest;
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friend class InterfaceTypeRequest;
@@ -2923,6 +2930,9 @@ class ValueDecl : public Decl {
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/// Is this declaration 'moveOnly'?
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bool isMoveOnly() const;
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/// Is this declaration escapable?
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bool isEscapable() const;
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/// Is this declaration marked with 'dynamic'?
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bool isDynamic() const;
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‎include/swift/AST/TypeCheckRequests.h

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@@ -427,6 +427,27 @@ class IsMoveOnlyRequest
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void cacheResult(bool value) const;
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};
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/// Determine whether the given declaration is escapable.
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class IsEscapableRequest
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: public SimpleRequest<IsEscapableRequest, bool(ValueDecl *),
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RequestFlags::SeparatelyCached> {
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public:
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using SimpleRequest::SimpleRequest;
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private:
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friend SimpleRequest;
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// Evaluation.
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bool evaluate(Evaluator &evaluator, ValueDecl *decl) const;
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public:
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// Separate caching.
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bool isCached() const { return true; }
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llvm::Optional<bool> getCachedResult() const;
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void cacheResult(bool value) const;
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};
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/// Determine whether the given declaration is 'dynamic''.
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class IsDynamicRequest :
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public SimpleRequest<IsDynamicRequest,

‎include/swift/AST/TypeCheckerTypeIDZone.def

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@@ -212,6 +212,8 @@ SWIFT_REQUEST(TypeChecker, IsFinalRequest, bool(ValueDecl *), SeparatelyCached,
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NoLocationInfo)
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SWIFT_REQUEST(TypeChecker, IsMoveOnlyRequest, bool(ValueDecl *), SeparatelyCached,
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NoLocationInfo)
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SWIFT_REQUEST(TypeChecker, IsEscapableRequest, bool(ValueDecl *),
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SeparatelyCached, NoLocationInfo)
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SWIFT_REQUEST(TypeChecker, IsGetterMutatingRequest, bool(AbstractStorageDecl *),
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SeparatelyCached, NoLocationInfo)
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SWIFT_REQUEST(TypeChecker, IsImplicitlyUnwrappedOptionalRequest,

‎lib/AST/Decl.cpp

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@@ -3562,6 +3562,12 @@ bool ValueDecl::isMoveOnly() const {
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getAttrs().hasAttribute<MoveOnlyAttr>());
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}
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bool ValueDecl::isEscapable() const {
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return evaluateOrDefault(getASTContext().evaluator,
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IsEscapableRequest{const_cast<ValueDecl *>(this)},
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!getAttrs().hasAttribute<NonEscapableAttr>());
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}
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bool ValueDecl::isDynamic() const {
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ASTContext &ctx = getASTContext();
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return evaluateOrDefault(ctx.evaluator,

‎lib/AST/TypeCheckRequests.cpp

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@@ -336,6 +336,29 @@ void IsMoveOnlyRequest::cacheResult(bool value) const {
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MoveOnlyAttr(/*Implicit=*/true));
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}
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//----------------------------------------------------------------------------//
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// isEscapable computation.
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//----------------------------------------------------------------------------//
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llvm::Optional<bool> IsEscapableRequest::getCachedResult() const {
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auto decl = std::get<0>(getStorage());
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if (decl->LazySemanticInfo.isEscapableComputed)
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return decl->LazySemanticInfo.isEscapable;
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return llvm::None;
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}
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void IsEscapableRequest::cacheResult(bool value) const {
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auto decl = std::get<0>(getStorage());
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decl->LazySemanticInfo.isEscapableComputed = true;
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decl->LazySemanticInfo.isEscapable = value;
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// Add an attribute for printing
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if (!value && !decl->getAttrs().hasAttribute<NonEscapableAttr>())
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decl->getAttrs().add(new (decl->getASTContext())
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NonEscapableAttr(/*Implicit=*/true));
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}
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//----------------------------------------------------------------------------//
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// isDynamic computation.
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//----------------------------------------------------------------------------//

‎lib/SIL/IR/TypeLowering.cpp

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@@ -2411,7 +2411,9 @@ namespace {
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return new (TC) MoveOnlyLoadableStructTypeLowering(
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structType, properties, Expansion);
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}
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if (!D->isEscapable()) {
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properties.setNonTrivial();
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}
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return handleAggregateByProperties<LoadableStructTypeLowering>(structType,
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properties);
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}

‎lib/SIL/Parser/ParseSIL.cpp

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@@ -7477,9 +7477,9 @@ bool SILParserState::parseSILGlobal(Parser &P) {
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parseDeclSILOptional(nullptr, &isSerialized, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, &isLet, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, &isLet, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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State, M) ||
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nullptr, State, M) ||
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P.parseToken(tok::at_sign, diag::expected_sil_value_name) ||
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P.parseIdentifier(GlobalName, NameLoc, /*diagnoseDollarPrefix=*/false,
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diag::expected_sil_value_name) ||
@@ -7531,7 +7531,7 @@ bool SILParserState::parseSILProperty(Parser &P) {
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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SP, M))
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nullptr, SP, M))
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return true;
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ValueDecl *VD;
@@ -7601,7 +7601,7 @@ bool SILParserState::parseSILVTable(Parser &P) {
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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VTableState, M))
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nullptr, VTableState, M))
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return true;
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// Parse the class name.
@@ -7712,7 +7712,7 @@ bool SILParserState::parseSILMoveOnlyDeinit(Parser &parser) {
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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moveOnlyDeinitTableState, M))
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nullptr, moveOnlyDeinitTableState, M))
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return true;
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// Parse the class name.
@@ -8199,7 +8199,7 @@ bool SILParserState::parseSILWitnessTable(Parser &P) {
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
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WitnessState, M))
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nullptr, WitnessState, M))
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return true;
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// Parse the protocol conformance.

‎lib/Sema/TypeCheckAttr.cpp

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@@ -161,6 +161,7 @@ class AttributeChecker : public AttributeVisitor<AttributeChecker> {
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IGNORED_ATTR(BackDeployed)
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IGNORED_ATTR(Documentation)
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IGNORED_ATTR(LexicalLifetimes)
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IGNORED_ATTR(NonEscapable)
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#undef IGNORED_ATTR
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void visitAlignmentAttr(AlignmentAttr *attr) {

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