diff options
Diffstat (limited to 'include/llvm/IR/Metadata.h')
| -rw-r--r-- | include/llvm/IR/Metadata.h | 947 |
1 files changed, 814 insertions, 133 deletions
diff --git a/include/llvm/IR/Metadata.h b/include/llvm/IR/Metadata.h index a056b0d..ff8f837 100644 --- a/include/llvm/IR/Metadata.h +++ b/include/llvm/IR/Metadata.h @@ -1,4 +1,4 @@ -//===-- llvm/Metadata.h - Metadata definitions ------------------*- C++ -*-===// +//===- llvm/IR/Metadata.h - Metadata definitions ----------------*- C++ -*-===// // // The LLVM Compiler Infrastructure // @@ -18,11 +18,13 @@ #include "llvm/ADT/ArrayRef.h" #include "llvm/ADT/DenseMap.h" -#include "llvm/ADT/FoldingSet.h" #include "llvm/ADT/ilist_node.h" #include "llvm/ADT/iterator_range.h" +#include "llvm/IR/Constant.h" +#include "llvm/IR/MetadataTracking.h" #include "llvm/IR/Value.h" #include "llvm/Support/ErrorHandling.h" +#include <type_traits> namespace llvm { class LLVMContext; @@ -38,20 +40,422 @@ enum LLVMConstants : uint32_t { /// \brief Root of the metadata hierarchy. /// /// This is a root class for typeless data in the IR. -/// -/// TODO: Detach from the Value hierarchy. -class Metadata : public Value { +class Metadata { + friend class ReplaceableMetadataImpl; + + /// \brief RTTI. + const unsigned char SubclassID; + +protected: + /// \brief Active type of storage. + enum StorageType { Uniqued, Distinct, Temporary }; + + /// \brief Storage flag for non-uniqued, otherwise unowned, metadata. + unsigned Storage : 2; + // TODO: expose remaining bits to subclasses. + + unsigned short SubclassData16; + unsigned SubclassData32; + +public: + enum MetadataKind { + MDTupleKind, + MDLocationKind, + GenericDebugNodeKind, + MDSubrangeKind, + MDEnumeratorKind, + MDBasicTypeKind, + MDDerivedTypeKind, + MDCompositeTypeKind, + MDSubroutineTypeKind, + MDFileKind, + MDCompileUnitKind, + MDSubprogramKind, + MDLexicalBlockKind, + MDLexicalBlockFileKind, + MDNamespaceKind, + MDTemplateTypeParameterKind, + MDTemplateValueParameterKind, + MDGlobalVariableKind, + MDLocalVariableKind, + MDExpressionKind, + MDObjCPropertyKind, + MDImportedEntityKind, + ConstantAsMetadataKind, + LocalAsMetadataKind, + MDStringKind + }; + protected: - Metadata(LLVMContext &Context, unsigned ID); + Metadata(unsigned ID, StorageType Storage) + : SubclassID(ID), Storage(Storage), SubclassData16(0), SubclassData32(0) { + } + ~Metadata() {} + + /// \brief Default handling of a changed operand, which asserts. + /// + /// If subclasses pass themselves in as owners to a tracking node reference, + /// they must provide an implementation of this method. + void handleChangedOperand(void *, Metadata *) { + llvm_unreachable("Unimplemented in Metadata subclass"); + } + +public: + unsigned getMetadataID() const { return SubclassID; } + + /// \brief User-friendly dump. + void dump() const; + void print(raw_ostream &OS) const; + void printAsOperand(raw_ostream &OS, bool PrintType = true, + const Module *M = nullptr) const; +}; + +#define HANDLE_METADATA(CLASS) class CLASS; +#include "llvm/IR/Metadata.def" + +inline raw_ostream &operator<<(raw_ostream &OS, const Metadata &MD) { + MD.print(OS); + return OS; +} + +/// \brief Metadata wrapper in the Value hierarchy. +/// +/// A member of the \a Value hierarchy to represent a reference to metadata. +/// This allows, e.g., instrinsics to have metadata as operands. +/// +/// Notably, this is the only thing in either hierarchy that is allowed to +/// reference \a LocalAsMetadata. +class MetadataAsValue : public Value { + friend class ReplaceableMetadataImpl; + friend class LLVMContextImpl; + + Metadata *MD; + + MetadataAsValue(Type *Ty, Metadata *MD); + ~MetadataAsValue(); + + /// \brief Drop use of metadata (during teardown). + void dropUse() { MD = nullptr; } public: + static MetadataAsValue *get(LLVMContext &Context, Metadata *MD); + static MetadataAsValue *getIfExists(LLVMContext &Context, Metadata *MD); + Metadata *getMetadata() const { return MD; } + static bool classof(const Value *V) { - return V->getValueID() == GenericMDNodeVal || - V->getValueID() == MDNodeFwdDeclVal || - V->getValueID() == MDStringVal; + return V->getValueID() == MetadataAsValueVal; } + +private: + void handleChangedMetadata(Metadata *MD); + void track(); + void untrack(); }; +/// \brief Shared implementation of use-lists for replaceable metadata. +/// +/// Most metadata cannot be RAUW'ed. This is a shared implementation of +/// use-lists and associated API for the two that support it (\a ValueAsMetadata +/// and \a TempMDNode). +class ReplaceableMetadataImpl { + friend class MetadataTracking; + +public: + typedef MetadataTracking::OwnerTy OwnerTy; + +private: + LLVMContext &Context; + uint64_t NextIndex; + SmallDenseMap<void *, std::pair<OwnerTy, uint64_t>, 4> UseMap; + +public: + ReplaceableMetadataImpl(LLVMContext &Context) + : Context(Context), NextIndex(0) {} + ~ReplaceableMetadataImpl() { + assert(UseMap.empty() && "Cannot destroy in-use replaceable metadata"); + } + + LLVMContext &getContext() const { return Context; } + + /// \brief Replace all uses of this with MD. + /// + /// Replace all uses of this with \c MD, which is allowed to be null. + void replaceAllUsesWith(Metadata *MD); + + /// \brief Resolve all uses of this. + /// + /// Resolve all uses of this, turning off RAUW permanently. If \c + /// ResolveUsers, call \a MDNode::resolve() on any users whose last operand + /// is resolved. + void resolveAllUses(bool ResolveUsers = true); + +private: + void addRef(void *Ref, OwnerTy Owner); + void dropRef(void *Ref); + void moveRef(void *Ref, void *New, const Metadata &MD); + + static ReplaceableMetadataImpl *get(Metadata &MD); +}; + +/// \brief Value wrapper in the Metadata hierarchy. +/// +/// This is a custom value handle that allows other metadata to refer to +/// classes in the Value hierarchy. +/// +/// Because of full uniquing support, each value is only wrapped by a single \a +/// ValueAsMetadata object, so the lookup maps are far more efficient than +/// those using ValueHandleBase. +class ValueAsMetadata : public Metadata, ReplaceableMetadataImpl { + friend class ReplaceableMetadataImpl; + friend class LLVMContextImpl; + + Value *V; + + /// \brief Drop users without RAUW (during teardown). + void dropUsers() { + ReplaceableMetadataImpl::resolveAllUses(/* ResolveUsers */ false); + } + +protected: + ValueAsMetadata(unsigned ID, Value *V) + : Metadata(ID, Uniqued), ReplaceableMetadataImpl(V->getContext()), V(V) { + assert(V && "Expected valid value"); + } + ~ValueAsMetadata() {} + +public: + static ValueAsMetadata *get(Value *V); + static ConstantAsMetadata *getConstant(Value *C) { + return cast<ConstantAsMetadata>(get(C)); + } + static LocalAsMetadata *getLocal(Value *Local) { + return cast<LocalAsMetadata>(get(Local)); + } + + static ValueAsMetadata *getIfExists(Value *V); + static ConstantAsMetadata *getConstantIfExists(Value *C) { + return cast_or_null<ConstantAsMetadata>(getIfExists(C)); + } + static LocalAsMetadata *getLocalIfExists(Value *Local) { + return cast_or_null<LocalAsMetadata>(getIfExists(Local)); + } + + Value *getValue() const { return V; } + Type *getType() const { return V->getType(); } + LLVMContext &getContext() const { return V->getContext(); } + + static void handleDeletion(Value *V); + static void handleRAUW(Value *From, Value *To); + +protected: + /// \brief Handle collisions after \a Value::replaceAllUsesWith(). + /// + /// RAUW isn't supported directly for \a ValueAsMetadata, but if the wrapped + /// \a Value gets RAUW'ed and the target already exists, this is used to + /// merge the two metadata nodes. + void replaceAllUsesWith(Metadata *MD) { + ReplaceableMetadataImpl::replaceAllUsesWith(MD); + } + +public: + static bool classof(const Metadata *MD) { + return MD->getMetadataID() == LocalAsMetadataKind || + MD->getMetadataID() == ConstantAsMetadataKind; + } +}; + +class ConstantAsMetadata : public ValueAsMetadata { + friend class ValueAsMetadata; + + ConstantAsMetadata(Constant *C) + : ValueAsMetadata(ConstantAsMetadataKind, C) {} + +public: + static ConstantAsMetadata *get(Constant *C) { + return ValueAsMetadata::getConstant(C); + } + static ConstantAsMetadata *getIfExists(Constant *C) { + return ValueAsMetadata::getConstantIfExists(C); + } + + Constant *getValue() const { + return cast<Constant>(ValueAsMetadata::getValue()); + } + + static bool classof(const Metadata *MD) { + return MD->getMetadataID() == ConstantAsMetadataKind; + } +}; + +class LocalAsMetadata : public ValueAsMetadata { + friend class ValueAsMetadata; + + LocalAsMetadata(Value *Local) + : ValueAsMetadata(LocalAsMetadataKind, Local) { + assert(!isa<Constant>(Local) && "Expected local value"); + } + +public: + static LocalAsMetadata *get(Value *Local) { + return ValueAsMetadata::getLocal(Local); + } + static LocalAsMetadata *getIfExists(Value *Local) { + return ValueAsMetadata::getLocalIfExists(Local); + } + + static bool classof(const Metadata *MD) { + return MD->getMetadataID() == LocalAsMetadataKind; + } +}; + +/// \brief Transitional API for extracting constants from Metadata. +/// +/// This namespace contains transitional functions for metadata that points to +/// \a Constants. +/// +/// In prehistory -- when metadata was a subclass of \a Value -- \a MDNode +/// operands could refer to any \a Value. There's was a lot of code like this: +/// +/// \code +/// MDNode *N = ...; +/// auto *CI = dyn_cast<ConstantInt>(N->getOperand(2)); +/// \endcode +/// +/// Now that \a Value and \a Metadata are in separate hierarchies, maintaining +/// the semantics for \a isa(), \a cast(), \a dyn_cast() (etc.) requires three +/// steps: cast in the \a Metadata hierarchy, extraction of the \a Value, and +/// cast in the \a Value hierarchy. Besides creating boiler-plate, this +/// requires subtle control flow changes. +/// +/// The end-goal is to create a new type of metadata, called (e.g.) \a MDInt, +/// so that metadata can refer to numbers without traversing a bridge to the \a +/// Value hierarchy. In this final state, the code above would look like this: +/// +/// \code +/// MDNode *N = ...; +/// auto *MI = dyn_cast<MDInt>(N->getOperand(2)); +/// \endcode +/// +/// The API in this namespace supports the transition. \a MDInt doesn't exist +/// yet, and even once it does, changing each metadata schema to use it is its +/// own mini-project. In the meantime this API prevents us from introducing +/// complex and bug-prone control flow that will disappear in the end. In +/// particular, the above code looks like this: +/// +/// \code +/// MDNode *N = ...; +/// auto *CI = mdconst::dyn_extract<ConstantInt>(N->getOperand(2)); +/// \endcode +/// +/// The full set of provided functions includes: +/// +/// mdconst::hasa <=> isa +/// mdconst::extract <=> cast +/// mdconst::extract_or_null <=> cast_or_null +/// mdconst::dyn_extract <=> dyn_cast +/// mdconst::dyn_extract_or_null <=> dyn_cast_or_null +/// +/// The target of the cast must be a subclass of \a Constant. +namespace mdconst { + +namespace detail { +template <class T> T &make(); +template <class T, class Result> struct HasDereference { + typedef char Yes[1]; + typedef char No[2]; + template <size_t N> struct SFINAE {}; + + template <class U, class V> + static Yes &hasDereference(SFINAE<sizeof(static_cast<V>(*make<U>()))> * = 0); + template <class U, class V> static No &hasDereference(...); + + static const bool value = + sizeof(hasDereference<T, Result>(nullptr)) == sizeof(Yes); +}; +template <class V, class M> struct IsValidPointer { + static const bool value = std::is_base_of<Constant, V>::value && + HasDereference<M, const Metadata &>::value; +}; +template <class V, class M> struct IsValidReference { + static const bool value = std::is_base_of<Constant, V>::value && + std::is_convertible<M, const Metadata &>::value; +}; +} // end namespace detail + +/// \brief Check whether Metadata has a Value. +/// +/// As an analogue to \a isa(), check whether \c MD has an \a Value inside of +/// type \c X. +template <class X, class Y> +inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, bool>::type +hasa(Y &&MD) { + assert(MD && "Null pointer sent into hasa"); + if (auto *V = dyn_cast<ConstantAsMetadata>(MD)) + return isa<X>(V->getValue()); + return false; +} +template <class X, class Y> +inline + typename std::enable_if<detail::IsValidReference<X, Y &>::value, bool>::type + hasa(Y &MD) { + return hasa(&MD); +} + +/// \brief Extract a Value from Metadata. +/// +/// As an analogue to \a cast(), extract the \a Value subclass \c X from \c MD. +template <class X, class Y> +inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type +extract(Y &&MD) { + return cast<X>(cast<ConstantAsMetadata>(MD)->getValue()); +} +template <class X, class Y> +inline + typename std::enable_if<detail::IsValidReference<X, Y &>::value, X *>::type + extract(Y &MD) { + return extract(&MD); +} + +/// \brief Extract a Value from Metadata, allowing null. +/// +/// As an analogue to \a cast_or_null(), extract the \a Value subclass \c X +/// from \c MD, allowing \c MD to be null. +template <class X, class Y> +inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type +extract_or_null(Y &&MD) { + if (auto *V = cast_or_null<ConstantAsMetadata>(MD)) + return cast<X>(V->getValue()); + return nullptr; +} + +/// \brief Extract a Value from Metadata, if any. +/// +/// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X +/// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a +/// Value it does contain is of the wrong subclass. +template <class X, class Y> +inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type +dyn_extract(Y &&MD) { + if (auto *V = dyn_cast<ConstantAsMetadata>(MD)) + return dyn_cast<X>(V->getValue()); + return nullptr; +} + +/// \brief Extract a Value from Metadata, if any, allowing null. +/// +/// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X +/// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a +/// Value it does contain is of the wrong subclass, allowing \c MD to be null. +template <class X, class Y> +inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type +dyn_extract_or_null(Y &&MD) { + if (auto *V = dyn_cast_or_null<ConstantAsMetadata>(MD)) + return dyn_cast<X>(V->getValue()); + return nullptr; +} + +} // end namespace mdconst + //===----------------------------------------------------------------------===// /// \brief A single uniqued string. /// @@ -60,14 +464,13 @@ public: class MDString : public Metadata { friend class StringMapEntry<MDString>; - virtual void anchor(); - MDString(const MDString &) LLVM_DELETED_FUNCTION; - - explicit MDString(LLVMContext &Context) - : Metadata(Context, Value::MDStringVal) {} + MDString(const MDString &) = delete; + MDString &operator=(MDString &&) = delete; + MDString &operator=(const MDString &) = delete; - /// \brief Shadow Value::getName() to prevent its use. - StringRef getName() const LLVM_DELETED_FUNCTION; + StringMapEntry<MDString> *Entry; + MDString() : Metadata(MDStringKind, Uniqued), Entry(nullptr) {} + MDString(MDString &&) : Metadata(MDStringKind, Uniqued) {} public: static MDString *get(LLVMContext &Context, StringRef Str); @@ -87,9 +490,12 @@ public: /// \brief Pointer to one byte past the end of the string. iterator end() const { return getString().end(); } + const unsigned char *bytes_begin() const { return getString().bytes_begin(); } + const unsigned char *bytes_end() const { return getString().bytes_end(); } + /// \brief Methods for support type inquiry through isa, cast, and dyn_cast. - static bool classof(const Value *V) { - return V->getValueID() == MDStringVal; + static bool classof(const Metadata *MD) { + return MD->getMetadataID() == MDStringKind; } }; @@ -106,7 +512,7 @@ struct AAMDNodes { bool operator!=(const AAMDNodes &A) const { return !(*this == A); } - LLVM_EXPLICIT operator bool() const { return TBAA || Scope || NoAlias; } + explicit operator bool() const { return TBAA || Scope || NoAlias; } /// \brief The tag for type-based alias analysis. MDNode *TBAA; @@ -137,21 +543,171 @@ struct DenseMapInfo<AAMDNodes> { } }; -class MDNodeOperand; +/// \brief Tracking metadata reference owned by Metadata. +/// +/// Similar to \a TrackingMDRef, but it's expected to be owned by an instance +/// of \a Metadata, which has the option of registering itself for callbacks to +/// re-unique itself. +/// +/// In particular, this is used by \a MDNode. +class MDOperand { + MDOperand(MDOperand &&) = delete; + MDOperand(const MDOperand &) = delete; + MDOperand &operator=(MDOperand &&) = delete; + MDOperand &operator=(const MDOperand &) = delete; -//===----------------------------------------------------------------------===// -/// \brief Tuple of metadata. + Metadata *MD; + +public: + MDOperand() : MD(nullptr) {} + ~MDOperand() { untrack(); } + + Metadata *get() const { return MD; } + operator Metadata *() const { return get(); } + Metadata *operator->() const { return get(); } + Metadata &operator*() const { return *get(); } + + void reset() { + untrack(); + MD = nullptr; + } + void reset(Metadata *MD, Metadata *Owner) { + untrack(); + this->MD = MD; + track(Owner); + } + +private: + void track(Metadata *Owner) { + if (MD) { + if (Owner) + MetadataTracking::track(this, *MD, *Owner); + else + MetadataTracking::track(MD); + } + } + void untrack() { + assert(static_cast<void *>(this) == &MD && "Expected same address"); + if (MD) + MetadataTracking::untrack(MD); + } +}; + +template <> struct simplify_type<MDOperand> { + typedef Metadata *SimpleType; + static SimpleType getSimplifiedValue(MDOperand &MD) { return MD.get(); } +}; + +template <> struct simplify_type<const MDOperand> { + typedef Metadata *SimpleType; + static SimpleType getSimplifiedValue(const MDOperand &MD) { return MD.get(); } +}; + +/// \brief Pointer to the context, with optional RAUW support. +/// +/// Either a raw (non-null) pointer to the \a LLVMContext, or an owned pointer +/// to \a ReplaceableMetadataImpl (which has a reference to \a LLVMContext). +class ContextAndReplaceableUses { + PointerUnion<LLVMContext *, ReplaceableMetadataImpl *> Ptr; + + ContextAndReplaceableUses() = delete; + ContextAndReplaceableUses(ContextAndReplaceableUses &&) = delete; + ContextAndReplaceableUses(const ContextAndReplaceableUses &) = delete; + ContextAndReplaceableUses &operator=(ContextAndReplaceableUses &&) = delete; + ContextAndReplaceableUses & + operator=(const ContextAndReplaceableUses &) = delete; + +public: + ContextAndReplaceableUses(LLVMContext &Context) : Ptr(&Context) {} + ContextAndReplaceableUses( + std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses) + : Ptr(ReplaceableUses.release()) { + assert(getReplaceableUses() && "Expected non-null replaceable uses"); + } + ~ContextAndReplaceableUses() { delete getReplaceableUses(); } + + operator LLVMContext &() { return getContext(); } + + /// \brief Whether this contains RAUW support. + bool hasReplaceableUses() const { + return Ptr.is<ReplaceableMetadataImpl *>(); + } + LLVMContext &getContext() const { + if (hasReplaceableUses()) + return getReplaceableUses()->getContext(); + return *Ptr.get<LLVMContext *>(); + } + ReplaceableMetadataImpl *getReplaceableUses() const { + if (hasReplaceableUses()) + return Ptr.get<ReplaceableMetadataImpl *>(); + return nullptr; + } + + /// \brief Assign RAUW support to this. + /// + /// Make this replaceable, taking ownership of \c ReplaceableUses (which must + /// not be null). + void + makeReplaceable(std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses) { + assert(ReplaceableUses && "Expected non-null replaceable uses"); + assert(&ReplaceableUses->getContext() == &getContext() && + "Expected same context"); + delete getReplaceableUses(); + Ptr = ReplaceableUses.release(); + } + + /// \brief Drop RAUW support. + /// + /// Cede ownership of RAUW support, returning it. + std::unique_ptr<ReplaceableMetadataImpl> takeReplaceableUses() { + assert(hasReplaceableUses() && "Expected to own replaceable uses"); + std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses( + getReplaceableUses()); + Ptr = &ReplaceableUses->getContext(); + return ReplaceableUses; + } +}; + +struct TempMDNodeDeleter { + inline void operator()(MDNode *Node) const; +}; + +#define HANDLE_MDNODE_LEAF(CLASS) \ + typedef std::unique_ptr<CLASS, TempMDNodeDeleter> Temp##CLASS; +#define HANDLE_MDNODE_BRANCH(CLASS) HANDLE_MDNODE_LEAF(CLASS) +#include "llvm/IR/Metadata.def" + +/// \brief Metadata node. +/// +/// Metadata nodes can be uniqued, like constants, or distinct. Temporary +/// metadata nodes (with full support for RAUW) can be used to delay uniquing +/// until forward references are known. The basic metadata node is an \a +/// MDTuple. +/// +/// There is limited support for RAUW at construction time. At construction +/// time, if any operand is a temporary node (or an unresolved uniqued node, +/// which indicates a transitive temporary operand), the node itself will be +/// unresolved. As soon as all operands become resolved, it will drop RAUW +/// support permanently. +/// +/// If an unresolved node is part of a cycle, \a resolveCycles() needs +/// to be called on some member of the cycle once all temporary nodes have been +/// replaced. class MDNode : public Metadata { - MDNode(const MDNode &) LLVM_DELETED_FUNCTION; - void operator=(const MDNode &) LLVM_DELETED_FUNCTION; - friend class MDNodeOperand; + friend class ReplaceableMetadataImpl; friend class LLVMContextImpl; - void *operator new(size_t) LLVM_DELETED_FUNCTION; + + MDNode(const MDNode &) = delete; + void operator=(const MDNode &) = delete; + void *operator new(size_t) = delete; + + unsigned NumOperands; + unsigned NumUnresolved; protected: - void *operator new(size_t Size, unsigned NumOps); + ContextAndReplaceableUses Context; - /// \brief Required by std, but never called. + void *operator new(size_t Size, unsigned NumOps); void operator delete(void *Mem); /// \brief Required by std, but never called. @@ -164,83 +720,188 @@ protected: llvm_unreachable("Constructor throws?"); } - /// \brief Subclass data enums. - enum { - /// FunctionLocalBit - This bit is set if this MDNode is function local. - /// This is true when it (potentially transitively) contains a reference to - /// something in a function, like an argument, basicblock, or instruction. - FunctionLocalBit = 1 << 0, + MDNode(LLVMContext &Context, unsigned ID, StorageType Storage, + ArrayRef<Metadata *> Ops1, ArrayRef<Metadata *> Ops2 = None); + ~MDNode() {} - /// NotUniquedBit - This is set on MDNodes that are not uniqued because they - /// have a null operand. - NotUniquedBit = 1 << 1 - }; + void dropAllReferences(); - /// \brief FunctionLocal enums. - enum FunctionLocalness { - FL_Unknown = -1, - FL_No = 0, - FL_Yes = 1 - }; + MDOperand *mutable_begin() { return mutable_end() - NumOperands; } + MDOperand *mutable_end() { return reinterpret_cast<MDOperand *>(this); } - /// \brief Replace each instance of the given operand with a new value. - void replaceOperand(MDNodeOperand *Op, Value *NewVal); +public: + static inline MDTuple *get(LLVMContext &Context, ArrayRef<Metadata *> MDs); + static inline MDTuple *getIfExists(LLVMContext &Context, + ArrayRef<Metadata *> MDs); + static inline MDTuple *getDistinct(LLVMContext &Context, + ArrayRef<Metadata *> MDs); + static inline TempMDTuple getTemporary(LLVMContext &Context, + ArrayRef<Metadata *> MDs); - MDNode(LLVMContext &C, unsigned ID, ArrayRef<Value *> Vals, - bool isFunctionLocal); - ~MDNode() {} + /// \brief Create a (temporary) clone of this. + TempMDNode clone() const; - static MDNode *getMDNode(LLVMContext &C, ArrayRef<Value*> Vals, - FunctionLocalness FL, bool Insert = true); -public: - static MDNode *get(LLVMContext &Context, ArrayRef<Value*> Vals); - /// \brief Construct MDNode with an explicit function-localness. + /// \brief Deallocate a node created by getTemporary. /// - /// Don't analyze Vals; trust isFunctionLocal. - static MDNode *getWhenValsUnresolved(LLVMContext &Context, - ArrayRef<Value*> Vals, - bool isFunctionLocal); + /// Calls \c replaceAllUsesWith(nullptr) before deleting, so any remaining + /// references will be reset. + static void deleteTemporary(MDNode *N); - static MDNode *getIfExists(LLVMContext &Context, ArrayRef<Value*> Vals); + LLVMContext &getContext() const { return Context.getContext(); } + + /// \brief Replace a specific operand. + void replaceOperandWith(unsigned I, Metadata *New); - /// \brief Return a temporary MDNode + /// \brief Check if node is fully resolved. /// - /// For use in constructing cyclic MDNode structures. A temporary MDNode is - /// not uniqued, may be RAUW'd, and must be manually deleted with - /// deleteTemporary. - static MDNode *getTemporary(LLVMContext &Context, ArrayRef<Value*> Vals); + /// If \a isTemporary(), this always returns \c false; if \a isDistinct(), + /// this always returns \c true. + /// + /// If \a isUniqued(), returns \c true if this has already dropped RAUW + /// support (because all operands are resolved). + /// + /// As forward declarations are resolved, their containers should get + /// resolved automatically. However, if this (or one of its operands) is + /// involved in a cycle, \a resolveCycles() needs to be called explicitly. + bool isResolved() const { return !Context.hasReplaceableUses(); } - /// \brief Deallocate a node created by getTemporary. + bool isUniqued() const { return Storage == Uniqued; } + bool isDistinct() const { return Storage == Distinct; } + bool isTemporary() const { return Storage == Temporary; } + + /// \brief RAUW a temporary. /// - /// The node must not have any users. - static void deleteTemporary(MDNode *N); + /// \pre \a isTemporary() must be \c true. + void replaceAllUsesWith(Metadata *MD) { + assert(isTemporary() && "Expected temporary node"); + assert(!isResolved() && "Expected RAUW support"); + Context.getReplaceableUses()->replaceAllUsesWith(MD); + } - /// \brief Replace a specific operand. - void replaceOperandWith(unsigned i, Value *NewVal); + /// \brief Resolve cycles. + /// + /// Once all forward declarations have been resolved, force cycles to be + /// resolved. + /// + /// \pre No operands (or operands' operands, etc.) have \a isTemporary(). + void resolveCycles(); - /// \brief Return specified operand. - Value *getOperand(unsigned i) const LLVM_READONLY; + /// \brief Replace a temporary node with a permanent one. + /// + /// Try to create a uniqued version of \c N -- in place, if possible -- and + /// return it. If \c N cannot be uniqued, return a distinct node instead. + template <class T> + static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type + replaceWithPermanent(std::unique_ptr<T, TempMDNodeDeleter> N) { + return cast<T>(N.release()->replaceWithPermanentImpl()); + } - /// \brief Return number of MDNode operands. - unsigned getNumOperands() const { return NumOperands; } + /// \brief Replace a temporary node with a uniqued one. + /// + /// Create a uniqued version of \c N -- in place, if possible -- and return + /// it. Takes ownership of the temporary node. + /// + /// \pre N does not self-reference. + template <class T> + static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type + replaceWithUniqued(std::unique_ptr<T, TempMDNodeDeleter> N) { + return cast<T>(N.release()->replaceWithUniquedImpl()); + } - /// \brief Return whether MDNode is local to a function. - bool isFunctionLocal() const { - return (getSubclassDataFromValue() & FunctionLocalBit) != 0; + /// \brief Replace a temporary node with a distinct one. + /// + /// Create a distinct version of \c N -- in place, if possible -- and return + /// it. Takes ownership of the temporary node. + template <class T> + static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type + replaceWithDistinct(std::unique_ptr<T, TempMDNodeDeleter> N) { + return cast<T>(N.release()->replaceWithDistinctImpl()); } - /// \brief Return the first function-local operand's function. +private: + MDNode *replaceWithPermanentImpl(); + MDNode *replaceWithUniquedImpl(); + MDNode *replaceWithDistinctImpl(); + +protected: + /// \brief Set an operand. + /// + /// Sets the operand directly, without worrying about uniquing. + void setOperand(unsigned I, Metadata *New); + + void storeDistinctInContext(); + template <class T, class StoreT> + static T *storeImpl(T *N, StorageType Storage, StoreT &Store); + +private: + void handleChangedOperand(void *Ref, Metadata *New); + + void resolve(); + void resolveAfterOperandChange(Metadata *Old, Metadata *New); + void decrementUnresolvedOperandCount(); + unsigned countUnresolvedOperands(); + + /// \brief Mutate this to be "uniqued". /// - /// If this metadata is function-local and recursively has a function-local - /// operand, return the first such operand's parent function. Otherwise, - /// return null. getFunction() should not be used for performance- critical - /// code because it recursively visits all the MDNode's operands. - const Function *getFunction() const; + /// Mutate this so that \a isUniqued(). + /// \pre \a isTemporary(). + /// \pre already added to uniquing set. + void makeUniqued(); + + /// \brief Mutate this to be "distinct". + /// + /// Mutate this so that \a isDistinct(). + /// \pre \a isTemporary(). + void makeDistinct(); + + void deleteAsSubclass(); + MDNode *uniquify(); + void eraseFromStore(); + + template <class NodeTy> struct HasCachedHash; + template <class NodeTy> + static void dispatchRecalculateHash(NodeTy *N, std::true_type) { + N->recalculateHash(); + } + template <class NodeTy> + static void dispatchRecalculateHash(NodeTy *N, std::false_type) {} + template <class NodeTy> + static void dispatchResetHash(NodeTy *N, std::true_type) { + N->setHash(0); + } + template <class NodeTy> + static void dispatchResetHash(NodeTy *N, std::false_type) {} + +public: + typedef const MDOperand *op_iterator; + typedef iterator_range<op_iterator> op_range; + + op_iterator op_begin() const { + return const_cast<MDNode *>(this)->mutable_begin(); + } + op_iterator op_end() const { + return const_cast<MDNode *>(this)->mutable_end(); + } + op_range operands() const { return op_range(op_begin(), op_end()); } + + const MDOperand &getOperand(unsigned I) const { + assert(I < NumOperands && "Out of range"); + return op_begin()[I]; + } + + /// \brief Return number of MDNode operands. + unsigned getNumOperands() const { return NumOperands; } /// \brief Methods for support type inquiry through isa, cast, and dyn_cast: - static bool classof(const Value *V) { - return V->getValueID() == GenericMDNodeVal || - V->getValueID() == MDNodeFwdDeclVal; + static bool classof(const Metadata *MD) { + switch (MD->getMetadataID()) { + default: + return false; +#define HANDLE_MDNODE_LEAF(CLASS) \ + case CLASS##Kind: \ + return true; +#include "llvm/IR/Metadata.def" + } } /// \brief Check whether MDNode is a vtable access. @@ -250,72 +911,91 @@ public: static MDNode *concatenate(MDNode *A, MDNode *B); static MDNode *intersect(MDNode *A, MDNode *B); static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B); - static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B); static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B); static MDNode *getMostGenericRange(MDNode *A, MDNode *B); - -protected: - bool isNotUniqued() const { - return (getSubclassDataFromValue() & NotUniquedBit) != 0; - } - void setIsNotUniqued(); - - // Shadow Value::setValueSubclassData with a private forwarding method so that - // any future subclasses cannot accidentally use it. - void setValueSubclassData(unsigned short D) { - Value::setValueSubclassData(D); - } + static MDNode *getMostGenericAliasScope(MDNode *A, MDNode *B); }; -/// \brief Generic metadata node. -/// -/// Generic metadata nodes, with opt-out support for uniquing. -/// -/// Although nodes are uniqued by default, \a GenericMDNode has no support for -/// RAUW. If an operand change (due to RAUW or otherwise) causes a uniquing -/// collision, the uniquing bit is dropped. +/// \brief Tuple of metadata. /// -/// TODO: Make uniquing opt-out (status: mandatory, sometimes dropped). -/// TODO: Drop support for RAUW. -class GenericMDNode : public MDNode { - friend class MDNode; +/// This is the simple \a MDNode arbitrary tuple. Nodes are uniqued by +/// default based on their operands. +class MDTuple : public MDNode { friend class LLVMContextImpl; + friend class MDNode; + + MDTuple(LLVMContext &C, StorageType Storage, unsigned Hash, + ArrayRef<Metadata *> Vals) + : MDNode(C, MDTupleKind, Storage, Vals) { + setHash(Hash); + } + ~MDTuple() { dropAllReferences(); } - unsigned Hash; + void setHash(unsigned Hash) { SubclassData32 = Hash; } + void recalculateHash(); - GenericMDNode(LLVMContext &C, ArrayRef<Value *> Vals, bool isFunctionLocal) - : MDNode(C, GenericMDNodeVal, Vals, isFunctionLocal), Hash(0) {} - ~GenericMDNode(); + static MDTuple *getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs, + StorageType Storage, bool ShouldCreate = true); - void dropAllReferences(); + TempMDTuple cloneImpl() const { + return getTemporary(getContext(), + SmallVector<Metadata *, 4>(op_begin(), op_end())); + } public: /// \brief Get the hash, if any. - unsigned getHash() const { return Hash; } + unsigned getHash() const { return SubclassData32; } - static bool classof(const Value *V) { - return V->getValueID() == GenericMDNodeVal; + static MDTuple *get(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return getImpl(Context, MDs, Uniqued); + } + static MDTuple *getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return getImpl(Context, MDs, Uniqued, /* ShouldCreate */ false); } -}; -/// \brief Forward declaration of metadata. -/// -/// Forward declaration of metadata, in the form of a metadata node. Unlike \a -/// GenericMDNode, this class has support for RAUW and is suitable for forward -/// references. -class MDNodeFwdDecl : public MDNode { - friend class MDNode; + /// \brief Return a distinct node. + /// + /// Return a distinct node -- i.e., a node that is not uniqued. + static MDTuple *getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return getImpl(Context, MDs, Distinct); + } - MDNodeFwdDecl(LLVMContext &C, ArrayRef<Value *> Vals, bool isFunctionLocal) - : MDNode(C, MDNodeFwdDeclVal, Vals, isFunctionLocal) {} - ~MDNodeFwdDecl() {} + /// \brief Return a temporary node. + /// + /// For use in constructing cyclic MDNode structures. A temporary MDNode is + /// not uniqued, may be RAUW'd, and must be manually deleted with + /// deleteTemporary. + static TempMDTuple getTemporary(LLVMContext &Context, + ArrayRef<Metadata *> MDs) { + return TempMDTuple(getImpl(Context, MDs, Temporary)); + } -public: - static bool classof(const Value *V) { - return V->getValueID() == MDNodeFwdDeclVal; + /// \brief Return a (temporary) clone of this. + TempMDTuple clone() const { return cloneImpl(); } + + static bool classof(const Metadata *MD) { + return MD->getMetadataID() == MDTupleKind; } }; +MDTuple *MDNode::get(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return MDTuple::get(Context, MDs); +} +MDTuple *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return MDTuple::getIfExists(Context, MDs); +} +MDTuple *MDNode::getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs) { + return MDTuple::getDistinct(Context, MDs); +} +TempMDTuple MDNode::getTemporary(LLVMContext &Context, + ArrayRef<Metadata *> MDs) { + return MDTuple::getTemporary(Context, MDs); +} + +void TempMDNodeDeleter::operator()(MDNode *Node) const { + MDNode::deleteTemporary(Node); +} + //===----------------------------------------------------------------------===// /// \brief A tuple of MDNodes. /// @@ -328,11 +1008,11 @@ class NamedMDNode : public ilist_node<NamedMDNode> { friend struct ilist_traits<NamedMDNode>; friend class LLVMContextImpl; friend class Module; - NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION; + NamedMDNode(const NamedMDNode &) = delete; std::string Name; Module *Parent; - void *Operands; // SmallVector<TrackingVH<MDNode>, 4> + void *Operands; // SmallVector<TrackingMDRef, 4> void setParent(Module *M) { Parent = M; } @@ -390,6 +1070,7 @@ public: MDNode *getOperand(unsigned i) const; unsigned getNumOperands() const; void addOperand(MDNode *M); + void setOperand(unsigned I, MDNode *New); StringRef getName() const; void print(raw_ostream &ROS) const; void dump() const; |