1 //===- llvm/IR/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>
33 class ModuleSlotTracker;
35 enum LLVMConstants : uint32_t {
36 DEBUG_METADATA_VERSION = 3 // Current debug info version number.
39 /// \brief Root of the metadata hierarchy.
41 /// This is a root class for typeless data in the IR.
43 friend class ReplaceableMetadataImpl;
46 const unsigned char SubclassID;
49 /// \brief Active type of storage.
50 enum StorageType { Uniqued, Distinct, Temporary };
52 /// \brief Storage flag for non-uniqued, otherwise unowned, metadata.
54 // TODO: expose remaining bits to subclasses.
56 unsigned short SubclassData16;
57 unsigned SubclassData32;
74 DILexicalBlockFileKind,
77 DITemplateTypeParameterKind,
78 DITemplateValueParameterKind,
84 ConstantAsMetadataKind,
90 Metadata(unsigned ID, StorageType Storage)
91 : SubclassID(ID), Storage(Storage), SubclassData16(0), SubclassData32(0) {
93 ~Metadata() = default;
95 /// \brief Default handling of a changed operand, which asserts.
97 /// If subclasses pass themselves in as owners to a tracking node reference,
98 /// they must provide an implementation of this method.
99 void handleChangedOperand(void *, Metadata *) {
100 llvm_unreachable("Unimplemented in Metadata subclass");
104 unsigned getMetadataID() const { return SubclassID; }
106 /// \brief User-friendly dump.
108 /// If \c M is provided, metadata nodes will be numbered canonically;
109 /// otherwise, pointer addresses are substituted.
111 /// Note: this uses an explicit overload instead of default arguments so that
112 /// the nullptr version is easy to call from a debugger.
116 void dump(const Module *M) const;
121 /// Prints definition of \c this.
123 /// If \c M is provided, metadata nodes will be numbered canonically;
124 /// otherwise, pointer addresses are substituted.
126 void print(raw_ostream &OS, const Module *M = nullptr,
127 bool IsForDebug = false) const;
128 void print(raw_ostream &OS, ModuleSlotTracker &MST, const Module *M = nullptr,
129 bool IsForDebug = false) const;
132 /// \brief Print as operand.
134 /// Prints reference of \c this.
136 /// If \c M is provided, metadata nodes will be numbered canonically;
137 /// otherwise, pointer addresses are substituted.
139 void printAsOperand(raw_ostream &OS, const Module *M = nullptr) const;
140 void printAsOperand(raw_ostream &OS, ModuleSlotTracker &MST,
141 const Module *M = nullptr) const;
145 #define HANDLE_METADATA(CLASS) class CLASS;
146 #include "llvm/IR/Metadata.def"
148 // Provide specializations of isa so that we don't need definitions of
149 // subclasses to see if the metadata is a subclass.
150 #define HANDLE_METADATA_LEAF(CLASS) \
151 template <> struct isa_impl<CLASS, Metadata> { \
152 static inline bool doit(const Metadata &MD) { \
153 return MD.getMetadataID() == Metadata::CLASS##Kind; \
156 #include "llvm/IR/Metadata.def"
158 inline raw_ostream &operator<<(raw_ostream &OS, const Metadata &MD) {
163 /// \brief Metadata wrapper in the Value hierarchy.
165 /// A member of the \a Value hierarchy to represent a reference to metadata.
166 /// This allows, e.g., instrinsics to have metadata as operands.
168 /// Notably, this is the only thing in either hierarchy that is allowed to
169 /// reference \a LocalAsMetadata.
170 class MetadataAsValue : public Value {
171 friend class ReplaceableMetadataImpl;
172 friend class LLVMContextImpl;
176 MetadataAsValue(Type *Ty, Metadata *MD);
177 ~MetadataAsValue() override;
179 /// \brief Drop use of metadata (during teardown).
180 void dropUse() { MD = nullptr; }
183 static MetadataAsValue *get(LLVMContext &Context, Metadata *MD);
184 static MetadataAsValue *getIfExists(LLVMContext &Context, Metadata *MD);
185 Metadata *getMetadata() const { return MD; }
187 static bool classof(const Value *V) {
188 return V->getValueID() == MetadataAsValueVal;
192 void handleChangedMetadata(Metadata *MD);
197 /// \brief Shared implementation of use-lists for replaceable metadata.
199 /// Most metadata cannot be RAUW'ed. This is a shared implementation of
200 /// use-lists and associated API for the two that support it (\a ValueAsMetadata
201 /// and \a TempMDNode).
202 class ReplaceableMetadataImpl {
203 friend class MetadataTracking;
206 typedef MetadataTracking::OwnerTy OwnerTy;
209 LLVMContext &Context;
211 SmallDenseMap<void *, std::pair<OwnerTy, uint64_t>, 4> UseMap;
214 ReplaceableMetadataImpl(LLVMContext &Context)
215 : Context(Context), NextIndex(0) {}
216 ~ReplaceableMetadataImpl() {
217 assert(UseMap.empty() && "Cannot destroy in-use replaceable metadata");
220 LLVMContext &getContext() const { return Context; }
222 /// \brief Replace all uses of this with MD.
224 /// Replace all uses of this with \c MD, which is allowed to be null.
225 void replaceAllUsesWith(Metadata *MD);
227 /// \brief Resolve all uses of this.
229 /// Resolve all uses of this, turning off RAUW permanently. If \c
230 /// ResolveUsers, call \a MDNode::resolve() on any users whose last operand
232 void resolveAllUses(bool ResolveUsers = true);
235 void addRef(void *Ref, OwnerTy Owner);
236 void dropRef(void *Ref);
237 void moveRef(void *Ref, void *New, const Metadata &MD);
239 static ReplaceableMetadataImpl *get(Metadata &MD);
242 /// \brief Value wrapper in the Metadata hierarchy.
244 /// This is a custom value handle that allows other metadata to refer to
245 /// classes in the Value hierarchy.
247 /// Because of full uniquing support, each value is only wrapped by a single \a
248 /// ValueAsMetadata object, so the lookup maps are far more efficient than
249 /// those using ValueHandleBase.
250 class ValueAsMetadata : public Metadata, ReplaceableMetadataImpl {
251 friend class ReplaceableMetadataImpl;
252 friend class LLVMContextImpl;
256 /// \brief Drop users without RAUW (during teardown).
258 ReplaceableMetadataImpl::resolveAllUses(/* ResolveUsers */ false);
262 ValueAsMetadata(unsigned ID, Value *V)
263 : Metadata(ID, Uniqued), ReplaceableMetadataImpl(V->getContext()), V(V) {
264 assert(V && "Expected valid value");
266 ~ValueAsMetadata() = default;
269 static ValueAsMetadata *get(Value *V);
270 static ConstantAsMetadata *getConstant(Value *C) {
271 return cast<ConstantAsMetadata>(get(C));
273 static LocalAsMetadata *getLocal(Value *Local) {
274 return cast<LocalAsMetadata>(get(Local));
277 static ValueAsMetadata *getIfExists(Value *V);
278 static ConstantAsMetadata *getConstantIfExists(Value *C) {
279 return cast_or_null<ConstantAsMetadata>(getIfExists(C));
281 static LocalAsMetadata *getLocalIfExists(Value *Local) {
282 return cast_or_null<LocalAsMetadata>(getIfExists(Local));
285 Value *getValue() const { return V; }
286 Type *getType() const { return V->getType(); }
287 LLVMContext &getContext() const { return V->getContext(); }
289 static void handleDeletion(Value *V);
290 static void handleRAUW(Value *From, Value *To);
293 /// \brief Handle collisions after \a Value::replaceAllUsesWith().
295 /// RAUW isn't supported directly for \a ValueAsMetadata, but if the wrapped
296 /// \a Value gets RAUW'ed and the target already exists, this is used to
297 /// merge the two metadata nodes.
298 void replaceAllUsesWith(Metadata *MD) {
299 ReplaceableMetadataImpl::replaceAllUsesWith(MD);
303 static bool classof(const Metadata *MD) {
304 return MD->getMetadataID() == LocalAsMetadataKind ||
305 MD->getMetadataID() == ConstantAsMetadataKind;
309 class ConstantAsMetadata : public ValueAsMetadata {
310 friend class ValueAsMetadata;
312 ConstantAsMetadata(Constant *C)
313 : ValueAsMetadata(ConstantAsMetadataKind, C) {}
316 static ConstantAsMetadata *get(Constant *C) {
317 return ValueAsMetadata::getConstant(C);
319 static ConstantAsMetadata *getIfExists(Constant *C) {
320 return ValueAsMetadata::getConstantIfExists(C);
323 Constant *getValue() const {
324 return cast<Constant>(ValueAsMetadata::getValue());
327 static bool classof(const Metadata *MD) {
328 return MD->getMetadataID() == ConstantAsMetadataKind;
332 class LocalAsMetadata : public ValueAsMetadata {
333 friend class ValueAsMetadata;
335 LocalAsMetadata(Value *Local)
336 : ValueAsMetadata(LocalAsMetadataKind, Local) {
337 assert(!isa<Constant>(Local) && "Expected local value");
341 static LocalAsMetadata *get(Value *Local) {
342 return ValueAsMetadata::getLocal(Local);
344 static LocalAsMetadata *getIfExists(Value *Local) {
345 return ValueAsMetadata::getLocalIfExists(Local);
348 static bool classof(const Metadata *MD) {
349 return MD->getMetadataID() == LocalAsMetadataKind;
353 /// \brief Transitional API for extracting constants from Metadata.
355 /// This namespace contains transitional functions for metadata that points to
358 /// In prehistory -- when metadata was a subclass of \a Value -- \a MDNode
359 /// operands could refer to any \a Value. There's was a lot of code like this:
363 /// auto *CI = dyn_cast<ConstantInt>(N->getOperand(2));
366 /// Now that \a Value and \a Metadata are in separate hierarchies, maintaining
367 /// the semantics for \a isa(), \a cast(), \a dyn_cast() (etc.) requires three
368 /// steps: cast in the \a Metadata hierarchy, extraction of the \a Value, and
369 /// cast in the \a Value hierarchy. Besides creating boiler-plate, this
370 /// requires subtle control flow changes.
372 /// The end-goal is to create a new type of metadata, called (e.g.) \a MDInt,
373 /// so that metadata can refer to numbers without traversing a bridge to the \a
374 /// Value hierarchy. In this final state, the code above would look like this:
378 /// auto *MI = dyn_cast<MDInt>(N->getOperand(2));
381 /// The API in this namespace supports the transition. \a MDInt doesn't exist
382 /// yet, and even once it does, changing each metadata schema to use it is its
383 /// own mini-project. In the meantime this API prevents us from introducing
384 /// complex and bug-prone control flow that will disappear in the end. In
385 /// particular, the above code looks like this:
389 /// auto *CI = mdconst::dyn_extract<ConstantInt>(N->getOperand(2));
392 /// The full set of provided functions includes:
394 /// mdconst::hasa <=> isa
395 /// mdconst::extract <=> cast
396 /// mdconst::extract_or_null <=> cast_or_null
397 /// mdconst::dyn_extract <=> dyn_cast
398 /// mdconst::dyn_extract_or_null <=> dyn_cast_or_null
400 /// The target of the cast must be a subclass of \a Constant.
404 template <class T> T &make();
405 template <class T, class Result> struct HasDereference {
408 template <size_t N> struct SFINAE {};
410 template <class U, class V>
411 static Yes &hasDereference(SFINAE<sizeof(static_cast<V>(*make<U>()))> * = 0);
412 template <class U, class V> static No &hasDereference(...);
414 static const bool value =
415 sizeof(hasDereference<T, Result>(nullptr)) == sizeof(Yes);
417 template <class V, class M> struct IsValidPointer {
418 static const bool value = std::is_base_of<Constant, V>::value &&
419 HasDereference<M, const Metadata &>::value;
421 template <class V, class M> struct IsValidReference {
422 static const bool value = std::is_base_of<Constant, V>::value &&
423 std::is_convertible<M, const Metadata &>::value;
425 } // end namespace detail
427 /// \brief Check whether Metadata has a Value.
429 /// As an analogue to \a isa(), check whether \c MD has an \a Value inside of
431 template <class X, class Y>
432 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, bool>::type
434 assert(MD && "Null pointer sent into hasa");
435 if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
436 return isa<X>(V->getValue());
439 template <class X, class Y>
441 typename std::enable_if<detail::IsValidReference<X, Y &>::value, bool>::type
446 /// \brief Extract a Value from Metadata.
448 /// As an analogue to \a cast(), extract the \a Value subclass \c X from \c MD.
449 template <class X, class Y>
450 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
452 return cast<X>(cast<ConstantAsMetadata>(MD)->getValue());
454 template <class X, class Y>
456 typename std::enable_if<detail::IsValidReference<X, Y &>::value, X *>::type
461 /// \brief Extract a Value from Metadata, allowing null.
463 /// As an analogue to \a cast_or_null(), extract the \a Value subclass \c X
464 /// from \c MD, allowing \c MD to be null.
465 template <class X, class Y>
466 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
467 extract_or_null(Y &&MD) {
468 if (auto *V = cast_or_null<ConstantAsMetadata>(MD))
469 return cast<X>(V->getValue());
473 /// \brief Extract a Value from Metadata, if any.
475 /// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X
476 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
477 /// Value it does contain is of the wrong subclass.
478 template <class X, class Y>
479 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
480 dyn_extract(Y &&MD) {
481 if (auto *V = dyn_cast<ConstantAsMetadata>(MD))
482 return dyn_cast<X>(V->getValue());
486 /// \brief Extract a Value from Metadata, if any, allowing null.
488 /// As an analogue to \a dyn_cast_or_null(), extract the \a Value subclass \c X
489 /// from \c MD, return null if \c MD doesn't contain a \a Value or if the \a
490 /// Value it does contain is of the wrong subclass, allowing \c MD to be null.
491 template <class X, class Y>
492 inline typename std::enable_if<detail::IsValidPointer<X, Y>::value, X *>::type
493 dyn_extract_or_null(Y &&MD) {
494 if (auto *V = dyn_cast_or_null<ConstantAsMetadata>(MD))
495 return dyn_cast<X>(V->getValue());
499 } // end namespace mdconst
501 //===----------------------------------------------------------------------===//
502 /// \brief A single uniqued string.
504 /// These are used to efficiently contain a byte sequence for metadata.
505 /// MDString is always unnamed.
506 class MDString : public Metadata {
507 friend class StringMapEntry<MDString>;
509 MDString(const MDString &) = delete;
510 MDString &operator=(MDString &&) = delete;
511 MDString &operator=(const MDString &) = delete;
513 StringMapEntry<MDString> *Entry;
514 MDString() : Metadata(MDStringKind, Uniqued), Entry(nullptr) {}
515 MDString(MDString &&) : Metadata(MDStringKind, Uniqued) {}
518 static MDString *get(LLVMContext &Context, StringRef Str);
519 static MDString *get(LLVMContext &Context, const char *Str) {
520 return get(Context, Str ? StringRef(Str) : StringRef());
523 StringRef getString() const;
525 unsigned getLength() const { return (unsigned)getString().size(); }
527 typedef StringRef::iterator iterator;
529 /// \brief Pointer to the first byte of the string.
530 iterator begin() const { return getString().begin(); }
532 /// \brief Pointer to one byte past the end of the string.
533 iterator end() const { return getString().end(); }
535 const unsigned char *bytes_begin() const { return getString().bytes_begin(); }
536 const unsigned char *bytes_end() const { return getString().bytes_end(); }
538 /// \brief Methods for support type inquiry through isa, cast, and dyn_cast.
539 static bool classof(const Metadata *MD) {
540 return MD->getMetadataID() == MDStringKind;
544 /// \brief A collection of metadata nodes that might be associated with a
545 /// memory access used by the alias-analysis infrastructure.
547 explicit AAMDNodes(MDNode *T = nullptr, MDNode *S = nullptr,
549 : TBAA(T), Scope(S), NoAlias(N) {}
551 bool operator==(const AAMDNodes &A) const {
552 return TBAA == A.TBAA && Scope == A.Scope && NoAlias == A.NoAlias;
555 bool operator!=(const AAMDNodes &A) const { return !(*this == A); }
557 explicit operator bool() const { return TBAA || Scope || NoAlias; }
559 /// \brief The tag for type-based alias analysis.
562 /// \brief The tag for alias scope specification (used with noalias).
565 /// \brief The tag specifying the noalias scope.
569 // Specialize DenseMapInfo for AAMDNodes.
571 struct DenseMapInfo<AAMDNodes> {
572 static inline AAMDNodes getEmptyKey() {
573 return AAMDNodes(DenseMapInfo<MDNode *>::getEmptyKey(),
576 static inline AAMDNodes getTombstoneKey() {
577 return AAMDNodes(DenseMapInfo<MDNode *>::getTombstoneKey(),
580 static unsigned getHashValue(const AAMDNodes &Val) {
581 return DenseMapInfo<MDNode *>::getHashValue(Val.TBAA) ^
582 DenseMapInfo<MDNode *>::getHashValue(Val.Scope) ^
583 DenseMapInfo<MDNode *>::getHashValue(Val.NoAlias);
585 static bool isEqual(const AAMDNodes &LHS, const AAMDNodes &RHS) {
590 /// \brief Tracking metadata reference owned by Metadata.
592 /// Similar to \a TrackingMDRef, but it's expected to be owned by an instance
593 /// of \a Metadata, which has the option of registering itself for callbacks to
594 /// re-unique itself.
596 /// In particular, this is used by \a MDNode.
598 MDOperand(MDOperand &&) = delete;
599 MDOperand(const MDOperand &) = delete;
600 MDOperand &operator=(MDOperand &&) = delete;
601 MDOperand &operator=(const MDOperand &) = delete;
606 MDOperand() : MD(nullptr) {}
607 ~MDOperand() { untrack(); }
609 Metadata *get() const { return MD; }
610 operator Metadata *() const { return get(); }
611 Metadata *operator->() const { return get(); }
612 Metadata &operator*() const { return *get(); }
618 void reset(Metadata *MD, Metadata *Owner) {
625 void track(Metadata *Owner) {
628 MetadataTracking::track(this, *MD, *Owner);
630 MetadataTracking::track(MD);
634 assert(static_cast<void *>(this) == &MD && "Expected same address");
636 MetadataTracking::untrack(MD);
640 template <> struct simplify_type<MDOperand> {
641 typedef Metadata *SimpleType;
642 static SimpleType getSimplifiedValue(MDOperand &MD) { return MD.get(); }
645 template <> struct simplify_type<const MDOperand> {
646 typedef Metadata *SimpleType;
647 static SimpleType getSimplifiedValue(const MDOperand &MD) { return MD.get(); }
650 /// \brief Pointer to the context, with optional RAUW support.
652 /// Either a raw (non-null) pointer to the \a LLVMContext, or an owned pointer
653 /// to \a ReplaceableMetadataImpl (which has a reference to \a LLVMContext).
654 class ContextAndReplaceableUses {
655 PointerUnion<LLVMContext *, ReplaceableMetadataImpl *> Ptr;
657 ContextAndReplaceableUses() = delete;
658 ContextAndReplaceableUses(ContextAndReplaceableUses &&) = delete;
659 ContextAndReplaceableUses(const ContextAndReplaceableUses &) = delete;
660 ContextAndReplaceableUses &operator=(ContextAndReplaceableUses &&) = delete;
661 ContextAndReplaceableUses &
662 operator=(const ContextAndReplaceableUses &) = delete;
665 ContextAndReplaceableUses(LLVMContext &Context) : Ptr(&Context) {}
666 ContextAndReplaceableUses(
667 std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses)
668 : Ptr(ReplaceableUses.release()) {
669 assert(getReplaceableUses() && "Expected non-null replaceable uses");
671 ~ContextAndReplaceableUses() { delete getReplaceableUses(); }
673 operator LLVMContext &() { return getContext(); }
675 /// \brief Whether this contains RAUW support.
676 bool hasReplaceableUses() const {
677 return Ptr.is<ReplaceableMetadataImpl *>();
679 LLVMContext &getContext() const {
680 if (hasReplaceableUses())
681 return getReplaceableUses()->getContext();
682 return *Ptr.get<LLVMContext *>();
684 ReplaceableMetadataImpl *getReplaceableUses() const {
685 if (hasReplaceableUses())
686 return Ptr.get<ReplaceableMetadataImpl *>();
690 /// \brief Assign RAUW support to this.
692 /// Make this replaceable, taking ownership of \c ReplaceableUses (which must
695 makeReplaceable(std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses) {
696 assert(ReplaceableUses && "Expected non-null replaceable uses");
697 assert(&ReplaceableUses->getContext() == &getContext() &&
698 "Expected same context");
699 delete getReplaceableUses();
700 Ptr = ReplaceableUses.release();
703 /// \brief Drop RAUW support.
705 /// Cede ownership of RAUW support, returning it.
706 std::unique_ptr<ReplaceableMetadataImpl> takeReplaceableUses() {
707 assert(hasReplaceableUses() && "Expected to own replaceable uses");
708 std::unique_ptr<ReplaceableMetadataImpl> ReplaceableUses(
709 getReplaceableUses());
710 Ptr = &ReplaceableUses->getContext();
711 return ReplaceableUses;
715 struct TempMDNodeDeleter {
716 inline void operator()(MDNode *Node) const;
719 #define HANDLE_MDNODE_LEAF(CLASS) \
720 typedef std::unique_ptr<CLASS, TempMDNodeDeleter> Temp##CLASS;
721 #define HANDLE_MDNODE_BRANCH(CLASS) HANDLE_MDNODE_LEAF(CLASS)
722 #include "llvm/IR/Metadata.def"
724 /// \brief Metadata node.
726 /// Metadata nodes can be uniqued, like constants, or distinct. Temporary
727 /// metadata nodes (with full support for RAUW) can be used to delay uniquing
728 /// until forward references are known. The basic metadata node is an \a
731 /// There is limited support for RAUW at construction time. At construction
732 /// time, if any operand is a temporary node (or an unresolved uniqued node,
733 /// which indicates a transitive temporary operand), the node itself will be
734 /// unresolved. As soon as all operands become resolved, it will drop RAUW
735 /// support permanently.
737 /// If an unresolved node is part of a cycle, \a resolveCycles() needs
738 /// to be called on some member of the cycle once all temporary nodes have been
740 class MDNode : public Metadata {
741 friend class ReplaceableMetadataImpl;
742 friend class LLVMContextImpl;
744 MDNode(const MDNode &) = delete;
745 void operator=(const MDNode &) = delete;
746 void *operator new(size_t) = delete;
748 unsigned NumOperands;
749 unsigned NumUnresolved;
752 ContextAndReplaceableUses Context;
754 void *operator new(size_t Size, unsigned NumOps);
755 void operator delete(void *Mem);
757 /// \brief Required by std, but never called.
758 void operator delete(void *, unsigned) {
759 llvm_unreachable("Constructor throws?");
762 /// \brief Required by std, but never called.
763 void operator delete(void *, unsigned, bool) {
764 llvm_unreachable("Constructor throws?");
767 MDNode(LLVMContext &Context, unsigned ID, StorageType Storage,
768 ArrayRef<Metadata *> Ops1, ArrayRef<Metadata *> Ops2 = None);
771 void dropAllReferences();
773 MDOperand *mutable_begin() { return mutable_end() - NumOperands; }
774 MDOperand *mutable_end() { return reinterpret_cast<MDOperand *>(this); }
776 typedef iterator_range<MDOperand *> mutable_op_range;
777 mutable_op_range mutable_operands() {
778 return mutable_op_range(mutable_begin(), mutable_end());
782 static inline MDTuple *get(LLVMContext &Context, ArrayRef<Metadata *> MDs);
783 static inline MDTuple *getIfExists(LLVMContext &Context,
784 ArrayRef<Metadata *> MDs);
785 static inline MDTuple *getDistinct(LLVMContext &Context,
786 ArrayRef<Metadata *> MDs);
787 static inline TempMDTuple getTemporary(LLVMContext &Context,
788 ArrayRef<Metadata *> MDs);
790 /// \brief Create a (temporary) clone of this.
791 TempMDNode clone() const;
793 /// \brief Deallocate a node created by getTemporary.
795 /// Calls \c replaceAllUsesWith(nullptr) before deleting, so any remaining
796 /// references will be reset.
797 static void deleteTemporary(MDNode *N);
799 LLVMContext &getContext() const { return Context.getContext(); }
801 /// \brief Replace a specific operand.
802 void replaceOperandWith(unsigned I, Metadata *New);
804 /// \brief Check if node is fully resolved.
806 /// If \a isTemporary(), this always returns \c false; if \a isDistinct(),
807 /// this always returns \c true.
809 /// If \a isUniqued(), returns \c true if this has already dropped RAUW
810 /// support (because all operands are resolved).
812 /// As forward declarations are resolved, their containers should get
813 /// resolved automatically. However, if this (or one of its operands) is
814 /// involved in a cycle, \a resolveCycles() needs to be called explicitly.
815 bool isResolved() const { return !Context.hasReplaceableUses(); }
817 bool isUniqued() const { return Storage == Uniqued; }
818 bool isDistinct() const { return Storage == Distinct; }
819 bool isTemporary() const { return Storage == Temporary; }
821 /// \brief RAUW a temporary.
823 /// \pre \a isTemporary() must be \c true.
824 void replaceAllUsesWith(Metadata *MD) {
825 assert(isTemporary() && "Expected temporary node");
826 assert(!isResolved() && "Expected RAUW support");
827 Context.getReplaceableUses()->replaceAllUsesWith(MD);
830 /// \brief Resolve cycles.
832 /// Once all forward declarations have been resolved, force cycles to be
835 /// \pre No operands (or operands' operands, etc.) have \a isTemporary().
836 void resolveCycles();
838 /// \brief Replace a temporary node with a permanent one.
840 /// Try to create a uniqued version of \c N -- in place, if possible -- and
841 /// return it. If \c N cannot be uniqued, return a distinct node instead.
843 static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
844 replaceWithPermanent(std::unique_ptr<T, TempMDNodeDeleter> N) {
845 return cast<T>(N.release()->replaceWithPermanentImpl());
848 /// \brief Replace a temporary node with a uniqued one.
850 /// Create a uniqued version of \c N -- in place, if possible -- and return
851 /// it. Takes ownership of the temporary node.
853 /// \pre N does not self-reference.
855 static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
856 replaceWithUniqued(std::unique_ptr<T, TempMDNodeDeleter> N) {
857 return cast<T>(N.release()->replaceWithUniquedImpl());
860 /// \brief Replace a temporary node with a distinct one.
862 /// Create a distinct version of \c N -- in place, if possible -- and return
863 /// it. Takes ownership of the temporary node.
865 static typename std::enable_if<std::is_base_of<MDNode, T>::value, T *>::type
866 replaceWithDistinct(std::unique_ptr<T, TempMDNodeDeleter> N) {
867 return cast<T>(N.release()->replaceWithDistinctImpl());
871 MDNode *replaceWithPermanentImpl();
872 MDNode *replaceWithUniquedImpl();
873 MDNode *replaceWithDistinctImpl();
876 /// \brief Set an operand.
878 /// Sets the operand directly, without worrying about uniquing.
879 void setOperand(unsigned I, Metadata *New);
881 void storeDistinctInContext();
882 template <class T, class StoreT>
883 static T *storeImpl(T *N, StorageType Storage, StoreT &Store);
884 template <class T> static T *storeImpl(T *N, StorageType Storage);
887 void handleChangedOperand(void *Ref, Metadata *New);
890 void resolveAfterOperandChange(Metadata *Old, Metadata *New);
891 void decrementUnresolvedOperandCount();
892 unsigned countUnresolvedOperands();
894 /// \brief Mutate this to be "uniqued".
896 /// Mutate this so that \a isUniqued().
897 /// \pre \a isTemporary().
898 /// \pre already added to uniquing set.
901 /// \brief Mutate this to be "distinct".
903 /// Mutate this so that \a isDistinct().
904 /// \pre \a isTemporary().
907 void deleteAsSubclass();
909 void eraseFromStore();
911 template <class NodeTy> struct HasCachedHash;
912 template <class NodeTy>
913 static void dispatchRecalculateHash(NodeTy *N, std::true_type) {
914 N->recalculateHash();
916 template <class NodeTy>
917 static void dispatchRecalculateHash(NodeTy *, std::false_type) {}
918 template <class NodeTy>
919 static void dispatchResetHash(NodeTy *N, std::true_type) {
922 template <class NodeTy>
923 static void dispatchResetHash(NodeTy *, std::false_type) {}
926 typedef const MDOperand *op_iterator;
927 typedef iterator_range<op_iterator> op_range;
929 op_iterator op_begin() const {
930 return const_cast<MDNode *>(this)->mutable_begin();
932 op_iterator op_end() const {
933 return const_cast<MDNode *>(this)->mutable_end();
935 op_range operands() const { return op_range(op_begin(), op_end()); }
937 const MDOperand &getOperand(unsigned I) const {
938 assert(I < NumOperands && "Out of range");
939 return op_begin()[I];
942 /// \brief Return number of MDNode operands.
943 unsigned getNumOperands() const { return NumOperands; }
945 /// \brief Methods for support type inquiry through isa, cast, and dyn_cast:
946 static bool classof(const Metadata *MD) {
947 switch (MD->getMetadataID()) {
950 #define HANDLE_MDNODE_LEAF(CLASS) \
953 #include "llvm/IR/Metadata.def"
957 /// \brief Check whether MDNode is a vtable access.
958 bool isTBAAVtableAccess() const;
960 /// \brief Methods for metadata merging.
961 static MDNode *concatenate(MDNode *A, MDNode *B);
962 static MDNode *intersect(MDNode *A, MDNode *B);
963 static MDNode *getMostGenericTBAA(MDNode *A, MDNode *B);
964 static MDNode *getMostGenericFPMath(MDNode *A, MDNode *B);
965 static MDNode *getMostGenericRange(MDNode *A, MDNode *B);
966 static MDNode *getMostGenericAliasScope(MDNode *A, MDNode *B);
967 static MDNode *getMostGenericAlignmentOrDereferenceable(MDNode *A, MDNode *B);
971 /// \brief Tuple of metadata.
973 /// This is the simple \a MDNode arbitrary tuple. Nodes are uniqued by
974 /// default based on their operands.
975 class MDTuple : public MDNode {
976 friend class LLVMContextImpl;
979 MDTuple(LLVMContext &C, StorageType Storage, unsigned Hash,
980 ArrayRef<Metadata *> Vals)
981 : MDNode(C, MDTupleKind, Storage, Vals) {
984 ~MDTuple() { dropAllReferences(); }
986 void setHash(unsigned Hash) { SubclassData32 = Hash; }
987 void recalculateHash();
989 static MDTuple *getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs,
990 StorageType Storage, bool ShouldCreate = true);
992 TempMDTuple cloneImpl() const {
993 return getTemporary(getContext(),
994 SmallVector<Metadata *, 4>(op_begin(), op_end()));
998 /// \brief Get the hash, if any.
999 unsigned getHash() const { return SubclassData32; }
1001 static MDTuple *get(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1002 return getImpl(Context, MDs, Uniqued);
1004 static MDTuple *getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1005 return getImpl(Context, MDs, Uniqued, /* ShouldCreate */ false);
1008 /// \brief Return a distinct node.
1010 /// Return a distinct node -- i.e., a node that is not uniqued.
1011 static MDTuple *getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1012 return getImpl(Context, MDs, Distinct);
1015 /// \brief Return a temporary node.
1017 /// For use in constructing cyclic MDNode structures. A temporary MDNode is
1018 /// not uniqued, may be RAUW'd, and must be manually deleted with
1019 /// deleteTemporary.
1020 static TempMDTuple getTemporary(LLVMContext &Context,
1021 ArrayRef<Metadata *> MDs) {
1022 return TempMDTuple(getImpl(Context, MDs, Temporary));
1025 /// \brief Return a (temporary) clone of this.
1026 TempMDTuple clone() const { return cloneImpl(); }
1028 static bool classof(const Metadata *MD) {
1029 return MD->getMetadataID() == MDTupleKind;
1033 MDTuple *MDNode::get(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1034 return MDTuple::get(Context, MDs);
1036 MDTuple *MDNode::getIfExists(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1037 return MDTuple::getIfExists(Context, MDs);
1039 MDTuple *MDNode::getDistinct(LLVMContext &Context, ArrayRef<Metadata *> MDs) {
1040 return MDTuple::getDistinct(Context, MDs);
1042 TempMDTuple MDNode::getTemporary(LLVMContext &Context,
1043 ArrayRef<Metadata *> MDs) {
1044 return MDTuple::getTemporary(Context, MDs);
1047 void TempMDNodeDeleter::operator()(MDNode *Node) const {
1048 MDNode::deleteTemporary(Node);
1051 /// \brief Typed iterator through MDNode operands.
1053 /// An iterator that transforms an \a MDNode::iterator into an iterator over a
1054 /// particular Metadata subclass.
1056 class TypedMDOperandIterator
1057 : std::iterator<std::input_iterator_tag, T *, std::ptrdiff_t, void, T *> {
1058 MDNode::op_iterator I = nullptr;
1061 TypedMDOperandIterator() = default;
1062 explicit TypedMDOperandIterator(MDNode::op_iterator I) : I(I) {}
1063 T *operator*() const { return cast_or_null<T>(*I); }
1064 TypedMDOperandIterator &operator++() {
1068 TypedMDOperandIterator operator++(int) {
1069 TypedMDOperandIterator Temp(*this);
1073 bool operator==(const TypedMDOperandIterator &X) const { return I == X.I; }
1074 bool operator!=(const TypedMDOperandIterator &X) const { return I != X.I; }
1077 /// \brief Typed, array-like tuple of metadata.
1079 /// This is a wrapper for \a MDTuple that makes it act like an array holding a
1080 /// particular type of metadata.
1081 template <class T> class MDTupleTypedArrayWrapper {
1082 const MDTuple *N = nullptr;
1085 MDTupleTypedArrayWrapper() = default;
1086 MDTupleTypedArrayWrapper(const MDTuple *N) : N(N) {}
1089 MDTupleTypedArrayWrapper(
1090 const MDTupleTypedArrayWrapper<U> &Other,
1091 typename std::enable_if<std::is_convertible<U *, T *>::value>::type * =
1096 explicit MDTupleTypedArrayWrapper(
1097 const MDTupleTypedArrayWrapper<U> &Other,
1098 typename std::enable_if<!std::is_convertible<U *, T *>::value>::type * =
1102 explicit operator bool() const { return get(); }
1103 explicit operator MDTuple *() const { return get(); }
1105 MDTuple *get() const { return const_cast<MDTuple *>(N); }
1106 MDTuple *operator->() const { return get(); }
1107 MDTuple &operator*() const { return *get(); }
1109 // FIXME: Fix callers and remove condition on N.
1110 unsigned size() const { return N ? N->getNumOperands() : 0u; }
1111 T *operator[](unsigned I) const { return cast_or_null<T>(N->getOperand(I)); }
1113 // FIXME: Fix callers and remove condition on N.
1114 typedef TypedMDOperandIterator<T> iterator;
1115 iterator begin() const { return N ? iterator(N->op_begin()) : iterator(); }
1116 iterator end() const { return N ? iterator(N->op_end()) : iterator(); }
1119 #define HANDLE_METADATA(CLASS) \
1120 typedef MDTupleTypedArrayWrapper<CLASS> CLASS##Array;
1121 #include "llvm/IR/Metadata.def"
1123 //===----------------------------------------------------------------------===//
1124 /// \brief A tuple of MDNodes.
1126 /// Despite its name, a NamedMDNode isn't itself an MDNode. NamedMDNodes belong
1127 /// to modules, have names, and contain lists of MDNodes.
1129 /// TODO: Inherit from Metadata.
1130 class NamedMDNode : public ilist_node<NamedMDNode> {
1131 friend struct ilist_traits<NamedMDNode>;
1132 friend class LLVMContextImpl;
1133 friend class Module;
1134 NamedMDNode(const NamedMDNode &) = delete;
1138 void *Operands; // SmallVector<TrackingMDRef, 4>
1140 void setParent(Module *M) { Parent = M; }
1142 explicit NamedMDNode(const Twine &N);
1144 template<class T1, class T2>
1145 class op_iterator_impl :
1146 public std::iterator<std::bidirectional_iterator_tag, T2> {
1147 const NamedMDNode *Node;
1149 op_iterator_impl(const NamedMDNode *N, unsigned i) : Node(N), Idx(i) { }
1151 friend class NamedMDNode;
1154 op_iterator_impl() : Node(nullptr), Idx(0) { }
1156 bool operator==(const op_iterator_impl &o) const { return Idx == o.Idx; }
1157 bool operator!=(const op_iterator_impl &o) const { return Idx != o.Idx; }
1158 op_iterator_impl &operator++() {
1162 op_iterator_impl operator++(int) {
1163 op_iterator_impl tmp(*this);
1167 op_iterator_impl &operator--() {
1171 op_iterator_impl operator--(int) {
1172 op_iterator_impl tmp(*this);
1177 T1 operator*() const { return Node->getOperand(Idx); }
1181 /// \brief Drop all references and remove the node from parent module.
1182 void eraseFromParent();
1184 /// \brief Remove all uses and clear node vector.
1185 void dropAllReferences();
1189 /// \brief Get the module that holds this named metadata collection.
1190 inline Module *getParent() { return Parent; }
1191 inline const Module *getParent() const { return Parent; }
1193 MDNode *getOperand(unsigned i) const;
1194 unsigned getNumOperands() const;
1195 void addOperand(MDNode *M);
1196 void setOperand(unsigned I, MDNode *New);
1197 StringRef getName() const;
1198 void print(raw_ostream &ROS, bool IsForDebug = false) const;
1201 // ---------------------------------------------------------------------------
1202 // Operand Iterator interface...
1204 typedef op_iterator_impl<MDNode *, MDNode> op_iterator;
1205 op_iterator op_begin() { return op_iterator(this, 0); }
1206 op_iterator op_end() { return op_iterator(this, getNumOperands()); }
1208 typedef op_iterator_impl<const MDNode *, MDNode> const_op_iterator;
1209 const_op_iterator op_begin() const { return const_op_iterator(this, 0); }
1210 const_op_iterator op_end() const { return const_op_iterator(this, getNumOperands()); }
1212 inline iterator_range<op_iterator> operands() {
1213 return make_range(op_begin(), op_end());
1215 inline iterator_range<const_op_iterator> operands() const {
1216 return make_range(op_begin(), op_end());
1220 } // end llvm namespace
1222 #endif // LLVM_IR_METADATA_H