1 //===-- llvm/Metadata.h - Metadata definitions ------------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
11 /// This file contains the declarations for metadata subclasses.
12 /// They represent the different flavors of metadata that live in LLVM.
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_IR_METADATA_H
17 #define LLVM_IR_METADATA_H
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/DenseMap.h"
21 #include "llvm/ADT/ilist_node.h"
22 #include "llvm/ADT/iterator_range.h"
23 #include "llvm/IR/Constant.h"
24 #include "llvm/IR/MetadataTracking.h"
25 #include "llvm/IR/Value.h"
26 #include "llvm/Support/ErrorHandling.h"
27 #include <type_traits>
32 template<typename ValueSubClass, typename ItemParentClass>
33 class SymbolTableListTraits;
36 enum LLVMConstants : uint32_t {
37 DEBUG_METADATA_VERSION = 2 // Current debug info version number.
40 /// \brief Root of the metadata hierarchy.
42 /// This is a root class for typeless data in the IR.
44 friend class ReplaceableMetadataImpl;
47 const unsigned char SubclassID;
50 /// \brief Storage flag for non-uniqued, otherwise unowned, metadata.
51 bool IsDistinctInContext : 1;
52 // TODO: expose remaining bits to subclasses.
54 unsigned short SubclassData16;
55 unsigned SubclassData32;
61 ConstantAsMetadataKind,
68 : SubclassID(ID), IsDistinctInContext(false), SubclassData16(0),
72 /// \brief Store this in a big non-uniqued untyped bucket.
73 bool isStoredDistinctInContext() const { return IsDistinctInContext; }
75 /// \brief Default handling of a changed operand, which asserts.
77 /// If subclasses pass themselves in as owners to a tracking node reference,
78 /// they must provide an implementation of this method.
79 void handleChangedOperand(void *, Metadata *) {
80 llvm_unreachable("Unimplemented in Metadata subclass");
84 unsigned getMetadataID() const { return SubclassID; }
86 /// \brief User-friendly dump.
88 void print(raw_ostream &OS) const;
89 void printAsOperand(raw_ostream &OS, bool PrintType = true,
90 const Module *M = nullptr) const;
93 #define HANDLE_METADATA(CLASS) class CLASS;
94 #include "llvm/IR/Metadata.def"
96 inline raw_ostream &operator<<(raw_ostream &OS, const Metadata &MD) {
101 /// \brief Metadata wrapper in the Value hierarchy.
103 /// A member of the \a Value hierarchy to represent a reference to metadata.
104 /// This allows, e.g., instrinsics to have metadata as operands.
106 /// Notably, this is the only thing in either hierarchy that is allowed to
107 /// reference \a LocalAsMetadata.
108 class MetadataAsValue : public Value {
109 friend class ReplaceableMetadataImpl;
110 friend class LLVMContextImpl;
114 MetadataAsValue(Type *Ty, Metadata *MD);
118 static MetadataAsValue *get(LLVMContext &Context, Metadata *MD);
119 static MetadataAsValue *getIfExists(LLVMContext &Context, Metadata *MD);
120 Metadata *getMetadata() const { return MD; }
122 static bool classof(const Value *V) {
123 return V->getValueID() == MetadataAsValueVal;
127 void handleChangedMetadata(Metadata *MD);
132 /// \brief Shared implementation of use-lists for replaceable metadata.
134 /// Most metadata cannot be RAUW'ed. This is a shared implementation of
135 /// use-lists and associated API for the two that support it (\a ValueAsMetadata
136 /// and \a TempMDNode).
137 class ReplaceableMetadataImpl {
138 friend class MetadataTracking;
141 typedef MetadataTracking::OwnerTy OwnerTy;
145 SmallDenseMap<void *, std::pair<OwnerTy, uint64_t>, 4> UseMap;
148 ReplaceableMetadataImpl() : NextIndex(0) {}
149 ~ReplaceableMetadataImpl() {
150 assert(UseMap.empty() && "Cannot destroy in-use replaceable metadata");
153 /// \brief Replace all uses of this with MD.
155 /// Replace all uses of this with \c MD, which is allowed to be null.
156 void replaceAllUsesWith(Metadata *MD);
158 /// \brief Resolve all uses of this.
160 /// Resolve all uses of this, turning off RAUW permanently. If \c
161 /// ResolveUsers, call \a UniquableMDNode::resolve() on any users whose last
162 /// operand is resolved.
163 void resolveAllUses(bool ResolveUsers = true);
166 void addRef(void *Ref, OwnerTy Owner);
167 void dropRef(void *Ref);
168 void moveRef(void *Ref, void *New, const Metadata &MD);
170 static ReplaceableMetadataImpl *get(Metadata &MD);
173 /// \brief Value wrapper in the Metadata hierarchy.
175 /// This is a custom value handle that allows other metadata to refer to
176 /// classes in the Value hierarchy.
178 /// Because of full uniquing support, each value is only wrapped by a single \a
179 /// ValueAsMetadata object, so the lookup maps are far more efficient than
180 /// those using ValueHandleBase.
181 class ValueAsMetadata : public Metadata, ReplaceableMetadataImpl {
182 friend class ReplaceableMetadataImpl;
183 friend class LLVMContextImpl;
188 ValueAsMetadata(unsigned ID, Value *V)
189 : Metadata(ID), V(V) {
190 assert(V && "Expected valid value");
192 ~ValueAsMetadata() {}
195 static ValueAsMetadata *get(Value *V);
196 static ConstantAsMetadata *getConstant(Value *C) {
197 return cast<ConstantAsMetadata>(get(C));
199 static LocalAsMetadata *getLocal(Value *Local) {
200 return cast<LocalAsMetadata>(get(Local));
203 static ValueAsMetadata *getIfExists(Value *V);
204 static ConstantAsMetadata *getConstantIfExists(Value *C) {
205 return cast_or_null<ConstantAsMetadata>(getIfExists(C));
207 static LocalAsMetadata *getLocalIfExists(Value *Local) {
208 return cast_or_null<LocalAsMetadata>(getIfExists(Local));
211 Value *getValue() const { return V; }
212 Type *getType() const { return V->getType(); }
213 LLVMContext &getContext() const { return V->getContext(); }
215 static void handleDeletion(Value *V);
216 static void handleRAUW(Value *From, Value *To);
219 /// \brief Handle collisions after \a Value::replaceAllUsesWith().
221 /// RAUW isn't supported directly for \a ValueAsMetadata, but if the wrapped
222 /// \a Value gets RAUW'ed and the target already exists, this is used to
223 /// merge the two metadata nodes.
224 void replaceAllUsesWith(Metadata *MD) {
225 ReplaceableMetadataImpl::replaceAllUsesWith(MD);
229 static bool classof(const Metadata *MD) {
230 return MD->getMetadataID() == LocalAsMetadataKind ||
231 MD->getMetadataID() == ConstantAsMetadataKind;
235 class ConstantAsMetadata : public ValueAsMetadata {
236 friend class ValueAsMetadata;
238 ConstantAsMetadata(Constant *C)
239 : ValueAsMetadata(ConstantAsMetadataKind, C) {}
242 static ConstantAsMetadata *get(Constant *C) {
243 return ValueAsMetadata::getConstant(C);
245 static ConstantAsMetadata *getIfExists(Constant *C) {
246 return ValueAsMetadata::getConstantIfExists(C);
249 Constant *getValue() const {
250 return cast<Constant>(ValueAsMetadata::getValue());
253 static bool classof(const Metadata *MD) {
254 return MD->getMetadataID() == ConstantAsMetadataKind;
258 class LocalAsMetadata : public ValueAsMetadata {
259 friend class ValueAsMetadata;
261 LocalAsMetadata(Value *Local)
262 : ValueAsMetadata(LocalAsMetadataKind, Local) {
263 assert(!isa<Constant>(Local) && "Expected local value");
267 static LocalAsMetadata *get(Value *Local) {
268 return ValueAsMetadata::getLocal(Local);
270 static LocalAsMetadata *getIfExists(Value *Local) {
271 return ValueAsMetadata::getLocalIfExists(Local);
274 static bool classof(const Metadata *MD) {
275 return MD->getMetadataID() == LocalAsMetadataKind;
279 /// \brief Transitional API for extracting constants from Metadata.
281 /// This namespace contains transitional functions for metadata that points to
284 /// In prehistory -- when metadata was a subclass of \a Value -- \a MDNode
285 /// operands could refer to any \a Value. There's was a lot of code like this:
289 /// auto *CI = dyn_cast<ConstantInt>(N->getOperand(2));
292 /// Now that \a Value and \a Metadata are in separate hierarchies, maintaining
293 /// the semantics for \a isa(), \a cast(), \a dyn_cast() (etc.) requires three
294 /// steps: cast in the \a Metadata hierarchy, extraction of the \a Value, and
295 /// cast in the \a Value hierarchy. Besides creating boiler-plate, this
296 /// requires subtle control flow changes.
298 /// The end-goal is to create a new type of metadata, called (e.g.) \a MDInt,
299 /// so that metadata can refer to numbers without traversing a bridge to the \a
300 /// Value hierarchy. In this final state, the code above would look like this:
304 /// auto *MI = dyn_cast<MDInt>(N->getOperand(2));
307 /// The API in this namespace supports the transition. \a MDInt doesn't exist
308 /// yet, and even once it does, changing each metadata schema to use it is its
309 /// own mini-project. In the meantime this API prevents us from introducing
310 /// complex and bug-prone control flow that will disappear in the end. In
311 /// particular, the above code looks like this:
315 /// auto *CI = mdconst::dyn_extract<ConstantInt>(N->getOperand(2));
318 /// The full set of provided functions includes:
320 /// mdconst::hasa <=> isa
321 /// mdconst::extract <=> cast
322 /// mdconst::extract_or_null <=> cast_or_null
323 /// mdconst::dyn_extract <=> dyn_cast
324 /// mdconst::dyn_extract_or_null <=> dyn_cast_or_null
326 /// The target of the cast must be a subclass of \a Constant.
330 template <class T> T &make();
331 template <class T, class Result> struct HasDereference {
334 template <size_t N> struct SFINAE {};
336 template <class U, class V>
337 static Yes &hasDereference(SFINAE<sizeof(static_cast<V>(*make<U>()))> * = 0);
338 template <class U, class V> static No &hasDereference(...);
340 static const bool value =
341 sizeof(hasDereference<T, Result>(nullptr)) == sizeof(Yes);
343 template <class V, class M> struct IsValidPointer {
344 static const bool value = std::is_base_of<Constant, V>::value &&
345 HasDereference<M, const Metadata &>::value;
347 template <class V, class M> struct IsValidReference {
348 static const bool value = std::is_base_of<Constant, V>::value &&
349 std::is_convertible<M, const Metadata &>::value;
351 } // end namespace detail
353 /// \brief Check whether Metadata has a Value.
355 /// As an analogue to \a isa(), check whether \c MD has an \a Value inside of
357 template <class X, class Y>
358 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, bool>::type
360 assert(MD && "Null pointer sent into hasa");
361 if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
362 return isa<X>(V->getValue());
365 template <class X, class Y>
367 typename std::enable_if<detail::IsValidReference<X, Y &>::value, bool>::type
372 /// \brief Extract a Value from Metadata.
374 /// As an analogue to \a cast(), extract the \a Value subclass \c X from \c MD.
375 template <class X, class Y>
376 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
378 return cast<X>(cast<ConstantAsMetadata>(MD)->getValue());
380 template <class X, class Y>
382 typename std::enable_if<detail::IsValidReference<X, Y &>::value, X *>::type
387 /// \brief Extract a Value from Metadata, allowing null.
389 /// As an analogue to \a cast_or_null(), extract the \a Value subclass \c X
390 /// from \c MD, allowing \c MD to be null.
391 template <class X, class Y>
392 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
393 extract_or_null(Y &&MD) {
394 if (auto *V = cast_or_null<ConstantAsMetadata>(MD))
395 return cast<X>(V->getValue());
399 /// \brief Extract a Value from Metadata, if any.
401 /// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X
402 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
403 /// Value it does contain is of the wrong subclass.
404 template <class X, class Y>
405 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
406 dyn_extract(Y &&MD) {
407 if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
408 return dyn_cast<X>(V->getValue());
412 /// \brief Extract a Value from Metadata, if any, allowing null.
414 /// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X
415 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
416 /// Value it does contain is of the wrong subclass, allowing \c MD to be null.
417 template <class X, class Y>
418 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
419 dyn_extract_or_null(Y &&MD) {
420 if (auto *V = dyn_cast_or_null<ConstantAsMetadata>(MD))
421 return dyn_cast<X>(V->getValue());
425 } // end namespace mdconst
427 //===----------------------------------------------------------------------===//
428 /// \brief A single uniqued string.
430 /// These are used to efficiently contain a byte sequence for metadata.
431 /// MDString is always unnamed.
432 class MDString : public Metadata {
433 friend class StringMapEntry<MDString>;
435 MDString(const MDString &) LLVM_DELETED_FUNCTION;
436 MDString &operator=(MDString &&) LLVM_DELETED_FUNCTION;
437 MDString &operator=(const MDString &) LLVM_DELETED_FUNCTION;
439 StringMapEntry<MDString> *Entry;
440 MDString() : Metadata(MDStringKind), Entry(nullptr) {}
441 MDString(MDString &&) : Metadata(MDStringKind) {}
444 static MDString *get(LLVMContext &Context, StringRef Str);
445 static MDString *get(LLVMContext &Context, const char *Str) {
446 return get(Context, Str ? StringRef(Str) : StringRef());
449 StringRef getString() const;
451 unsigned getLength() const { return (unsigned)getString().size(); }
453 typedef StringRef::iterator iterator;
455 /// \brief Pointer to the first byte of the string.
456 iterator begin() const { return getString().begin(); }
458 /// \brief Pointer to one byte past the end of the string.
459 iterator end() const { return getString().end(); }
461 const unsigned char *bytes_begin() const { return getString().bytes_begin(); }
462 const unsigned char *bytes_end() const { return getString().bytes_end(); }
464 /// \brief Methods for support type inquiry through isa, cast, and dyn_cast.
465 static bool classof(const Metadata *MD) {
466 return MD->getMetadataID() == MDStringKind;
470 /// \brief A collection of metadata nodes that might be associated with a
471 /// memory access used by the alias-analysis infrastructure.
473 explicit AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr,
475 : TBAA(T), Scope(S), NoAlias(N) {}
477 bool operator==(const AAMDNodes &A) const {
478 return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias;
481 bool operator!=(const AAMDNodes &A) const { return !(*this == A); }
483 LLVM_EXPLICIT operator bool() const { return TBAA || Scope || NoAlias; }
485 /// \brief The tag for type-based alias analysis.
488 /// \brief The tag for alias scope specification (used with noalias).
491 /// \brief The tag specifying the noalias scope.
495 // Specialize DenseMapInfo for AAMDNodes.
497 struct DenseMapInfo<AAMDNodes> {
498 static inline AAMDNodes getEmptyKey() {
499 return AAMDNodes(DenseMapInfo<MDNode *>::getEmptyKey(), 0, 0);
501 static inline AAMDNodes getTombstoneKey() {
502 return AAMDNodes(DenseMapInfo<MDNode *>::getTombstoneKey(), 0, 0);
504 static unsigned getHashValue(const AAMDNodes &Val) {
505 return DenseMapInfo<MDNode *>::getHashValue(Val.TBAA) ^
506 DenseMapInfo<MDNode *>::getHashValue(Val.Scope) ^
507 DenseMapInfo<MDNode *>::getHashValue(Val.NoAlias);
509 static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) {
514 /// \brief Tracking metadata reference owned by Metadata.
516 /// Similar to \a TrackingMDRef, but it's expected to be owned by an instance
517 /// of \a Metadata, which has the option of registering itself for callbacks to
518 /// re-unique itself.
520 /// In particular, this is used by \a MDNode.
522 MDOperand(MDOperand &&) LLVM_DELETED_FUNCTION;
523 MDOperand(const MDOperand &) LLVM_DELETED_FUNCTION;
524 MDOperand &operator=(MDOperand &&) LLVM_DELETED_FUNCTION;
525 MDOperand &operator=(const MDOperand &) LLVM_DELETED_FUNCTION;
530 MDOperand() : MD(nullptr) {}
531 ~MDOperand() { untrack(); }
533 Metadata *get() const { return MD; }
534 operator Metadata *() const { return get(); }
535 Metadata *operator->() const { return get(); }
536 Metadata &operator*() const { return *get(); }
542 void reset(Metadata *MD, Metadata *Owner) {
549 void track(Metadata *Owner) {
552 MetadataTracking::track(this, *MD, *Owner);
554 MetadataTracking::track(MD);
558 assert(static_cast<void *>(this) == &MD && "Expected same address");
560 MetadataTracking::untrack(MD);
564 template <> struct simplify_type<MDOperand> {
565 typedef Metadata *SimpleType;
566 static SimpleType getSimplifiedValue(MDOperand &MD) { return MD.get(); }
569 template <> struct simplify_type<const MDOperand> {
570 typedef Metadata *SimpleType;
571 static SimpleType getSimplifiedValue(const MDOperand &MD) { return MD.get(); }
574 //===----------------------------------------------------------------------===//
575 /// \brief Tuple of metadata.
576 class MDNode : public Metadata {
577 MDNode(const MDNode &) LLVM_DELETED_FUNCTION;
578 void operator=(const MDNode &) LLVM_DELETED_FUNCTION;
579 void *operator new(size_t) LLVM_DELETED_FUNCTION;
581 LLVMContext &Context;
582 unsigned NumOperands;
585 unsigned MDNodeSubclassData;
587 void *operator new(size_t Size, unsigned NumOps);
588 void operator delete(void *Mem);
590 /// \brief Required by std, but never called.
591 void operator delete(void *, unsigned) {
592 llvm_unreachable("Constructor throws?");
595 /// \brief Required by std, but never called.
596 void operator delete(void *, unsigned, bool) {
597 llvm_unreachable("Constructor throws?");
600 MDNode(LLVMContext &Context, unsigned ID, ArrayRef<Metadata *> MDs);
603 void dropAllReferences();
605 MDOperand *mutable_begin() { return mutable_end() - NumOperands; }
606 MDOperand *mutable_end() { return reinterpret_cast<MDOperand *>(this); }
609 static inline MDNode *get(LLVMContext &Context, ArrayRef<Metadata *> MDs);
610 static inline MDNode *getIfExists(LLVMContext &Context,
611 ArrayRef<Metadata *> MDs);
612 static inline MDNode *getDistinct(LLVMContext &Context,
613 ArrayRef<Metadata *> MDs);
615 /// \brief Return a temporary MDNode
617 /// For use in constructing cyclic MDNode structures. A temporary MDNode is
618 /// not uniqued, may be RAUW'd, and must be manually deleted with
620 static MDNodeFwdDecl *getTemporary(LLVMContext &Context,
621 ArrayRef<Metadata *> MDs);
623 /// \brief Deallocate a node created by getTemporary.
625 /// The node must not have any users.
626 static void deleteTemporary(MDNode *N);
628 LLVMContext &getContext() const { return Context; }
630 /// \brief Replace a specific operand.
631 void replaceOperandWith(unsigned I, Metadata *New);
633 /// \brief Check if node is fully resolved.
634 bool isResolved() const;
636 /// \brief Check if node is distinct.
638 /// Distinct nodes are not uniqued, and will not be returned by \a
640 bool isDistinct() const {
641 return isStoredDistinctInContext() || isa<MDNodeFwdDecl>(this);
645 /// \brief Set an operand.
647 /// Sets the operand directly, without worrying about uniquing.
648 void setOperand(unsigned I, Metadata *New);
651 typedef const MDOperand *op_iterator;
652 typedef iterator_range<op_iterator> op_range;
654 op_iterator op_begin() const {
655 return const_cast<MDNode *>(this)->mutable_begin();
657 op_iterator op_end() const {
658 return const_cast<MDNode *>(this)->mutable_end();
660 op_range operands() const { return op_range(op_begin(), op_end()); }
662 const MDOperand &getOperand(unsigned I) const {
663 assert(I < NumOperands && "Out of range");
664 return op_begin()[I];
667 /// \brief Return number of MDNode operands.
668 unsigned getNumOperands() const { return NumOperands; }
670 /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
671 static bool classof(const Metadata *MD) {
672 return MD->getMetadataID() == MDTupleKind ||
673 MD->getMetadataID() == MDNodeFwdDeclKind;
676 /// \brief Check whether MDNode is a vtable access.
677 bool isTBAAVtableAccess() const;
679 /// \brief Methods for metadata merging.
680 static MDNode *concatenate(MDNode *A, MDNode *B);
681 static MDNode *intersect(MDNode *A, MDNode *B);
682 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
683 static AAMDNodes getMostGenericAA(const AAMDNodes &A, const AAMDNodes &B);
684 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
685 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
688 /// \brief Uniquable metadata node.
690 /// A uniquable metadata node. This contains the basic functionality
691 /// for implementing sub-types of \a MDNode that can be uniqued like
694 /// There is limited support for RAUW at construction time. At
695 /// construction time, if any operands are an instance of \a
696 /// MDNodeFwdDecl (or another unresolved \a UniquableMDNode, which
697 /// indicates an \a MDNodeFwdDecl in its path), the node itself will be
698 /// unresolved. As soon as all operands become resolved, it will drop
699 /// RAUW support permanently.
701 /// If an unresolved node is part of a cycle, \a resolveCycles() needs
702 /// to be called on some member of the cycle when each \a MDNodeFwdDecl
703 /// has been removed.
704 class UniquableMDNode : public MDNode {
705 friend class ReplaceableMetadataImpl;
707 friend class LLVMContextImpl;
709 /// \brief Support RAUW as long as one of its arguments is replaceable.
711 /// FIXME: Save memory by storing this in a pointer union with the
712 /// LLVMContext, and adding an LLVMContext reference to RMI.
713 std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses;
716 /// \brief Create a new node.
718 /// If \c AllowRAUW, then if any operands are unresolved support RAUW. RAUW
719 /// will be dropped once all operands have been resolved (or if \a
720 /// resolveCycles() is called).
721 UniquableMDNode(LLVMContext &C, unsigned ID, ArrayRef<Metadata *> Vals,
723 ~UniquableMDNode() {}
725 void storeDistinctInContext();
728 static bool classof(const Metadata *MD) {
729 return MD->getMetadataID() == MDTupleKind;
732 /// \brief Check whether any operands are forward declarations.
734 /// Returns \c true as long as any operands (or their operands, etc.) are \a
737 /// As forward declarations are resolved, their containers should get
738 /// resolved automatically. However, if this (or one of its operands) is
739 /// involved in a cycle, \a resolveCycles() needs to be called explicitly.
740 bool isResolved() const { return !ReplaceableUses; }
742 /// \brief Resolve cycles.
744 /// Once all forward declarations have been resolved, force cycles to be
747 /// \pre No operands (or operands' operands, etc.) are \a MDNodeFwdDecl.
748 void resolveCycles();
751 void handleChangedOperand(void *Ref, Metadata *New);
754 void resolveAfterOperandChange(Metadata *Old, Metadata *New);
755 void decrementUnresolvedOperandCount();
757 void deleteAsSubclass();
758 UniquableMDNode *uniquify();
759 void eraseFromStore();
762 /// \brief Tuple of metadata.
764 /// This is the simple \a MDNode arbitrary tuple. Nodes are uniqued by
765 /// default based on their operands.
766 class MDTuple : public UniquableMDNode {
767 friend class LLVMContextImpl;
768 friend class UniquableMDNode;
770 MDTuple(LLVMContext &C, ArrayRef<Metadata *> Vals, bool AllowRAUW)
771 : UniquableMDNode(C, MDTupleKind, Vals, AllowRAUW) {}
772 ~MDTuple() { dropAllReferences(); }
774 void setHash(unsigned Hash) { MDNodeSubclassData = Hash; }
775 void recalculateHash();
777 static MDTuple *getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs,
781 /// \brief Get the hash, if any.
782 unsigned getHash() const { return MDNodeSubclassData; }
784 static MDTuple *get(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
785 return getImpl(Context, MDs, /* ShouldCreate */ true);
787 static MDTuple *getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
788 return getImpl(Context, MDs, /* ShouldCreate */ false);
791 /// \brief Return a distinct node.
793 /// Return a distinct node -- i.e., a node that is not uniqued.
794 static MDTuple *getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs);
796 static bool classof(const Metadata *MD) {
797 return MD->getMetadataID() == MDTupleKind;
801 MDTuple *uniquifyImpl();
802 void eraseFromStoreImpl();
805 MDNode *MDNode::get(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
806 return MDTuple::get(Context, MDs);
808 MDNode *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
809 return MDTuple::getIfExists(Context, MDs);
811 MDNode *MDNode::getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
812 return MDTuple::getDistinct(Context, MDs);
815 /// \brief Forward declaration of metadata.
817 /// Forward declaration of metadata, in the form of a basic tuple. Unlike \a
818 /// MDTuple, this class has full support for RAUW, is not owned, is not
819 /// uniqued, and is suitable for forward references.
820 class MDNodeFwdDecl : public MDNode, ReplaceableMetadataImpl {
821 friend class Metadata;
822 friend class ReplaceableMetadataImpl;
824 MDNodeFwdDecl(LLVMContext &C, ArrayRef<Metadata *> Vals)
825 : MDNode(C, MDNodeFwdDeclKind, Vals) {}
828 ~MDNodeFwdDecl() { dropAllReferences(); }
829 using MDNode::operator delete;
831 static MDNodeFwdDecl *get(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
832 return new (MDs.size()) MDNodeFwdDecl(Context, MDs);
835 static bool classof(const Metadata *MD) {
836 return MD->getMetadataID() == MDNodeFwdDeclKind;
839 using ReplaceableMetadataImpl::replaceAllUsesWith;
842 //===----------------------------------------------------------------------===//
843 /// \brief A tuple of MDNodes.
845 /// Despite its name, a NamedMDNode isn't itself an MDNode. NamedMDNodes belong
846 /// to modules, have names, and contain lists of MDNodes.
848 /// TODO: Inherit from Metadata.
849 class NamedMDNode : public ilist_node<NamedMDNode> {
850 friend class SymbolTableListTraits<NamedMDNode, Module>;
851 friend struct ilist_traits<NamedMDNode>;
852 friend class LLVMContextImpl;
854 NamedMDNode(const NamedMDNode &) LLVM_DELETED_FUNCTION;
858 void *Operands; // SmallVector<TrackingMDRef, 4>
860 void setParent(Module *M) { Parent = M; }
862 explicit NamedMDNode(const Twine &N);
864 template<class T1, class T2>
865 class op_iterator_impl :
866 public std::iterator<std::bidirectional_iterator_tag, T2> {
867 const NamedMDNode *Node;
869 op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { }
871 friend class NamedMDNode;
874 op_iterator_impl() : Node(nullptr), Idx(0) { }
876 bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; }
877 bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; }
878 op_iterator_impl &operator++() {
882 op_iterator_impl operator++(int) {
883 op_iterator_impl tmp(*this);
887 op_iterator_impl &operator--() {
891 op_iterator_impl operator--(int) {
892 op_iterator_impl tmp(*this);
897 T1 operator*() const { return Node->getOperand(Idx); }
901 /// \brief Drop all references and remove the node from parent module.
902 void eraseFromParent();
904 /// \brief Remove all uses and clear node vector.
905 void dropAllReferences();
909 /// \brief Get the module that holds this named metadata collection.
910 inline Module *getParent() { return Parent; }
911 inline const Module *getParent() const { return Parent; }
913 MDNode *getOperand(unsigned i) const;
914 unsigned getNumOperands() const;
915 void addOperand(MDNode *M);
916 void setOperand(unsigned I, MDNode *New);
917 StringRef getName() const;
918 void print(raw_ostream &ROS) const;
921 // ---------------------------------------------------------------------------
922 // Operand Iterator interface...
924 typedef op_iterator_impl<MDNode *, MDNode> op_iterator;
925 op_iterator op_begin() { return op_iterator(this, 0); }
926 op_iterator op_end() { return op_iterator(this, getNumOperands()); }
928 typedef op_iterator_impl<const MDNode *, MDNode> const_op_iterator;
929 const_op_iterator op_begin() const { return const_op_iterator(this, 0); }
930 const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); }
932 inline iterator_range<op_iterator> operands() {
933 return iterator_range<op_iterator>(op_begin(), op_end());
935 inline iterator_range<const_op_iterator> operands() const {
936 return iterator_range<const_op_iterator>(op_begin(), op_end());
940 } // end llvm namespace