1 //===- Metadata.cpp - Implement Metadata classes --------------------------===//
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 //===----------------------------------------------------------------------===//
10 // This file implements the Metadata classes.
12 //===----------------------------------------------------------------------===//
14 #include "LLVMContextImpl.h"
15 #include "MetadataImpl.h"
16 #include "SymbolTableListTraitsImpl.h"
17 #include "llvm/ADT/APFloat.h"
18 #include "llvm/ADT/APInt.h"
19 #include "llvm/ADT/ArrayRef.h"
20 #include "llvm/ADT/DenseSet.h"
21 #include "llvm/ADT/None.h"
22 #include "llvm/ADT/STLExtras.h"
23 #include "llvm/ADT/SetVector.h"
24 #include "llvm/ADT/SmallPtrSet.h"
25 #include "llvm/ADT/SmallSet.h"
26 #include "llvm/ADT/SmallVector.h"
27 #include "llvm/ADT/StringMap.h"
28 #include "llvm/ADT/StringRef.h"
29 #include "llvm/ADT/Twine.h"
30 #include "llvm/IR/Argument.h"
31 #include "llvm/IR/BasicBlock.h"
32 #include "llvm/IR/Constant.h"
33 #include "llvm/IR/ConstantRange.h"
34 #include "llvm/IR/Constants.h"
35 #include "llvm/IR/DebugInfoMetadata.h"
36 #include "llvm/IR/DebugLoc.h"
37 #include "llvm/IR/Function.h"
38 #include "llvm/IR/GlobalObject.h"
39 #include "llvm/IR/GlobalVariable.h"
40 #include "llvm/IR/Instruction.h"
41 #include "llvm/IR/LLVMContext.h"
42 #include "llvm/IR/Metadata.h"
43 #include "llvm/IR/Module.h"
44 #include "llvm/IR/TrackingMDRef.h"
45 #include "llvm/IR/Type.h"
46 #include "llvm/IR/Value.h"
47 #include "llvm/IR/ValueHandle.h"
48 #include "llvm/Support/Casting.h"
49 #include "llvm/Support/ErrorHandling.h"
50 #include "llvm/Support/MathExtras.h"
57 #include <type_traits>
63 MetadataAsValue::MetadataAsValue(Type *Ty, Metadata *MD)
64 : Value(Ty, MetadataAsValueVal), MD(MD) {
68 MetadataAsValue::~MetadataAsValue() {
69 getType()->getContext().pImpl->MetadataAsValues.erase(MD);
73 /// Canonicalize metadata arguments to intrinsics.
75 /// To support bitcode upgrades (and assembly semantic sugar) for \a
76 /// MetadataAsValue, we need to canonicalize certain metadata.
78 /// - nullptr is replaced by an empty MDNode.
79 /// - An MDNode with a single null operand is replaced by an empty MDNode.
80 /// - An MDNode whose only operand is a \a ConstantAsMetadata gets skipped.
82 /// This maintains readability of bitcode from when metadata was a type of
83 /// value, and these bridges were unnecessary.
84 static Metadata *canonicalizeMetadataForValue(LLVMContext &Context,
88 return MDNode::get(Context, None);
90 // Return early if this isn't a single-operand MDNode.
91 auto *N = dyn_cast<MDNode>(MD);
92 if (!N || N->getNumOperands() != 1)
95 if (!N->getOperand(0))
97 return MDNode::get(Context, None);
99 if (auto *C = dyn_cast<ConstantAsMetadata>(N->getOperand(0)))
100 // Look through the MDNode.
106 MetadataAsValue *MetadataAsValue::get(LLVMContext &Context, Metadata *MD) {
107 MD = canonicalizeMetadataForValue(Context, MD);
108 auto *&Entry = Context.pImpl->MetadataAsValues[MD];
110 Entry = new MetadataAsValue(Type::getMetadataTy(Context), MD);
114 MetadataAsValue *MetadataAsValue::getIfExists(LLVMContext &Context,
116 MD = canonicalizeMetadataForValue(Context, MD);
117 auto &Store = Context.pImpl->MetadataAsValues;
118 return Store.lookup(MD);
121 void MetadataAsValue::handleChangedMetadata(Metadata *MD) {
122 LLVMContext &Context = getContext();
123 MD = canonicalizeMetadataForValue(Context, MD);
124 auto &Store = Context.pImpl->MetadataAsValues;
126 // Stop tracking the old metadata.
127 Store.erase(this->MD);
131 // Start tracking MD, or RAUW if necessary.
132 auto *&Entry = Store[MD];
134 replaceAllUsesWith(Entry);
144 void MetadataAsValue::track() {
146 MetadataTracking::track(&MD, *MD, *this);
149 void MetadataAsValue::untrack() {
151 MetadataTracking::untrack(MD);
154 bool MetadataTracking::track(void *Ref, Metadata &MD, OwnerTy Owner) {
155 assert(Ref && "Expected live reference");
156 assert((Owner || *static_cast<Metadata **>(Ref) == &MD) &&
157 "Reference without owner must be direct");
158 if (auto *R = ReplaceableMetadataImpl::getOrCreate(MD)) {
159 R->addRef(Ref, Owner);
162 if (auto *PH = dyn_cast<DistinctMDOperandPlaceholder>(&MD)) {
163 assert(!PH->Use && "Placeholders can only be used once");
164 assert(!Owner && "Unexpected callback to owner");
165 PH->Use = static_cast<Metadata **>(Ref);
171 void MetadataTracking::untrack(void *Ref, Metadata &MD) {
172 assert(Ref && "Expected live reference");
173 if (auto *R = ReplaceableMetadataImpl::getIfExists(MD))
175 else if (auto *PH = dyn_cast<DistinctMDOperandPlaceholder>(&MD))
179 bool MetadataTracking::retrack(void *Ref, Metadata &MD, void *New) {
180 assert(Ref && "Expected live reference");
181 assert(New && "Expected live reference");
182 assert(Ref != New && "Expected change");
183 if (auto *R = ReplaceableMetadataImpl::getIfExists(MD)) {
184 R->moveRef(Ref, New, MD);
187 assert(!isa<DistinctMDOperandPlaceholder>(MD) &&
188 "Unexpected move of an MDOperand");
189 assert(!isReplaceable(MD) &&
190 "Expected un-replaceable metadata, since we didn't move a reference");
194 bool MetadataTracking::isReplaceable(const Metadata &MD) {
195 return ReplaceableMetadataImpl::isReplaceable(MD);
198 void ReplaceableMetadataImpl::addRef(void *Ref, OwnerTy Owner) {
200 UseMap.insert(std::make_pair(Ref, std::make_pair(Owner, NextIndex)))
203 assert(WasInserted && "Expected to add a reference");
206 assert(NextIndex != 0 && "Unexpected overflow");
209 void ReplaceableMetadataImpl::dropRef(void *Ref) {
210 bool WasErased = UseMap.erase(Ref);
212 assert(WasErased && "Expected to drop a reference");
215 void ReplaceableMetadataImpl::moveRef(void *Ref, void *New,
216 const Metadata &MD) {
217 auto I = UseMap.find(Ref);
218 assert(I != UseMap.end() && "Expected to move a reference");
219 auto OwnerAndIndex = I->second;
221 bool WasInserted = UseMap.insert(std::make_pair(New, OwnerAndIndex)).second;
223 assert(WasInserted && "Expected to add a reference");
225 // Check that the references are direct if there's no owner.
227 assert((OwnerAndIndex.first || *static_cast<Metadata **>(Ref) == &MD) &&
228 "Reference without owner must be direct");
229 assert((OwnerAndIndex.first || *static_cast<Metadata **>(New) == &MD) &&
230 "Reference without owner must be direct");
233 void ReplaceableMetadataImpl::replaceAllUsesWith(Metadata *MD) {
237 // Copy out uses since UseMap will get touched below.
238 using UseTy = std::pair<void *, std::pair<OwnerTy, uint64_t>>;
239 SmallVector<UseTy, 8> Uses(UseMap.begin(), UseMap.end());
240 llvm::sort(Uses.begin(), Uses.end(), [](const UseTy &L, const UseTy &R) {
241 return L.second.second < R.second.second;
243 for (const auto &Pair : Uses) {
244 // Check that this Ref hasn't disappeared after RAUW (when updating a
246 if (!UseMap.count(Pair.first))
249 OwnerTy Owner = Pair.second.first;
251 // Update unowned tracking references directly.
252 Metadata *&Ref = *static_cast<Metadata **>(Pair.first);
255 MetadataTracking::track(Ref);
256 UseMap.erase(Pair.first);
260 // Check for MetadataAsValue.
261 if (Owner.is<MetadataAsValue *>()) {
262 Owner.get<MetadataAsValue *>()->handleChangedMetadata(MD);
266 // There's a Metadata owner -- dispatch.
267 Metadata *OwnerMD = Owner.get<Metadata *>();
268 switch (OwnerMD->getMetadataID()) {
269 #define HANDLE_METADATA_LEAF(CLASS) \
270 case Metadata::CLASS##Kind: \
271 cast<CLASS>(OwnerMD)->handleChangedOperand(Pair.first, MD); \
273 #include "llvm/IR/Metadata.def"
275 llvm_unreachable("Invalid metadata subclass");
278 assert(UseMap.empty() && "Expected all uses to be replaced");
281 void ReplaceableMetadataImpl::resolveAllUses(bool ResolveUsers) {
290 // Copy out uses since UseMap could get touched below.
291 using UseTy = std::pair<void *, std::pair<OwnerTy, uint64_t>>;
292 SmallVector<UseTy, 8> Uses(UseMap.begin(), UseMap.end());
293 llvm::sort(Uses.begin(), Uses.end(), [](const UseTy &L, const UseTy &R) {
294 return L.second.second < R.second.second;
297 for (const auto &Pair : Uses) {
298 auto Owner = Pair.second.first;
301 if (Owner.is<MetadataAsValue *>())
304 // Resolve MDNodes that point at this.
305 auto *OwnerMD = dyn_cast<MDNode>(Owner.get<Metadata *>());
308 if (OwnerMD->isResolved())
310 OwnerMD->decrementUnresolvedOperandCount();
314 ReplaceableMetadataImpl *ReplaceableMetadataImpl::getOrCreate(Metadata &MD) {
315 if (auto *N = dyn_cast<MDNode>(&MD))
316 return N->isResolved() ? nullptr : N->Context.getOrCreateReplaceableUses();
317 return dyn_cast<ValueAsMetadata>(&MD);
320 ReplaceableMetadataImpl *ReplaceableMetadataImpl::getIfExists(Metadata &MD) {
321 if (auto *N = dyn_cast<MDNode>(&MD))
322 return N->isResolved() ? nullptr : N->Context.getReplaceableUses();
323 return dyn_cast<ValueAsMetadata>(&MD);
326 bool ReplaceableMetadataImpl::isReplaceable(const Metadata &MD) {
327 if (auto *N = dyn_cast<MDNode>(&MD))
328 return !N->isResolved();
329 return dyn_cast<ValueAsMetadata>(&MD);
332 static DISubprogram *getLocalFunctionMetadata(Value *V) {
333 assert(V && "Expected value");
334 if (auto *A = dyn_cast<Argument>(V)) {
335 if (auto *Fn = A->getParent())
336 return Fn->getSubprogram();
340 if (BasicBlock *BB = cast<Instruction>(V)->getParent()) {
341 if (auto *Fn = BB->getParent())
342 return Fn->getSubprogram();
349 ValueAsMetadata *ValueAsMetadata::get(Value *V) {
350 assert(V && "Unexpected null Value");
352 auto &Context = V->getContext();
353 auto *&Entry = Context.pImpl->ValuesAsMetadata[V];
355 assert((isa<Constant>(V) || isa<Argument>(V) || isa<Instruction>(V)) &&
356 "Expected constant or function-local value");
357 assert(!V->IsUsedByMD && "Expected this to be the only metadata use");
358 V->IsUsedByMD = true;
359 if (auto *C = dyn_cast<Constant>(V))
360 Entry = new ConstantAsMetadata(C);
362 Entry = new LocalAsMetadata(V);
368 ValueAsMetadata *ValueAsMetadata::getIfExists(Value *V) {
369 assert(V && "Unexpected null Value");
370 return V->getContext().pImpl->ValuesAsMetadata.lookup(V);
373 void ValueAsMetadata::handleDeletion(Value *V) {
374 assert(V && "Expected valid value");
376 auto &Store = V->getType()->getContext().pImpl->ValuesAsMetadata;
377 auto I = Store.find(V);
378 if (I == Store.end())
381 // Remove old entry from the map.
382 ValueAsMetadata *MD = I->second;
383 assert(MD && "Expected valid metadata");
384 assert(MD->getValue() == V && "Expected valid mapping");
387 // Delete the metadata.
388 MD->replaceAllUsesWith(nullptr);
392 void ValueAsMetadata::handleRAUW(Value *From, Value *To) {
393 assert(From && "Expected valid value");
394 assert(To && "Expected valid value");
395 assert(From != To && "Expected changed value");
396 assert(From->getType() == To->getType() && "Unexpected type change");
398 LLVMContext &Context = From->getType()->getContext();
399 auto &Store = Context.pImpl->ValuesAsMetadata;
400 auto I = Store.find(From);
401 if (I == Store.end()) {
402 assert(!From->IsUsedByMD && "Expected From not to be used by metadata");
406 // Remove old entry from the map.
407 assert(From->IsUsedByMD && "Expected From to be used by metadata");
408 From->IsUsedByMD = false;
409 ValueAsMetadata *MD = I->second;
410 assert(MD && "Expected valid metadata");
411 assert(MD->getValue() == From && "Expected valid mapping");
414 if (isa<LocalAsMetadata>(MD)) {
415 if (auto *C = dyn_cast<Constant>(To)) {
416 // Local became a constant.
417 MD->replaceAllUsesWith(ConstantAsMetadata::get(C));
421 if (getLocalFunctionMetadata(From) && getLocalFunctionMetadata(To) &&
422 getLocalFunctionMetadata(From) != getLocalFunctionMetadata(To)) {
423 // DISubprogram changed.
424 MD->replaceAllUsesWith(nullptr);
428 } else if (!isa<Constant>(To)) {
429 // Changed to function-local value.
430 MD->replaceAllUsesWith(nullptr);
435 auto *&Entry = Store[To];
437 // The target already exists.
438 MD->replaceAllUsesWith(Entry);
443 // Update MD in place (and update the map entry).
444 assert(!To->IsUsedByMD && "Expected this to be the only metadata use");
445 To->IsUsedByMD = true;
450 //===----------------------------------------------------------------------===//
451 // MDString implementation.
454 MDString *MDString::get(LLVMContext &Context, StringRef Str) {
455 auto &Store = Context.pImpl->MDStringCache;
456 auto I = Store.try_emplace(Str);
457 auto &MapEntry = I.first->getValue();
460 MapEntry.Entry = &*I.first;
464 StringRef MDString::getString() const {
465 assert(Entry && "Expected to find string map entry");
466 return Entry->first();
469 //===----------------------------------------------------------------------===//
470 // MDNode implementation.
473 // Assert that the MDNode types will not be unaligned by the objects
474 // prepended to them.
475 #define HANDLE_MDNODE_LEAF(CLASS) \
477 alignof(uint64_t) >= alignof(CLASS), \
478 "Alignment is insufficient after objects prepended to " #CLASS);
479 #include "llvm/IR/Metadata.def"
481 void *MDNode::operator new(size_t Size, unsigned NumOps) {
482 size_t OpSize = NumOps * sizeof(MDOperand);
483 // uint64_t is the most aligned type we need support (ensured by static_assert
485 OpSize = alignTo(OpSize, alignof(uint64_t));
486 void *Ptr = reinterpret_cast<char *>(::operator new(OpSize + Size)) + OpSize;
487 MDOperand *O = static_cast<MDOperand *>(Ptr);
488 for (MDOperand *E = O - NumOps; O != E; --O)
489 (void)new (O - 1) MDOperand;
493 void MDNode::operator delete(void *Mem) {
494 MDNode *N = static_cast<MDNode *>(Mem);
495 size_t OpSize = N->NumOperands * sizeof(MDOperand);
496 OpSize = alignTo(OpSize, alignof(uint64_t));
498 MDOperand *O = static_cast<MDOperand *>(Mem);
499 for (MDOperand *E = O - N->NumOperands; O != E; --O)
500 (O - 1)->~MDOperand();
501 ::operator delete(reinterpret_cast<char *>(Mem) - OpSize);
504 MDNode::MDNode(LLVMContext &Context, unsigned ID, StorageType Storage,
505 ArrayRef<Metadata *> Ops1, ArrayRef<Metadata *> Ops2)
506 : Metadata(ID, Storage), NumOperands(Ops1.size() + Ops2.size()),
507 NumUnresolved(0), Context(Context) {
509 for (Metadata *MD : Ops1)
510 setOperand(Op++, MD);
511 for (Metadata *MD : Ops2)
512 setOperand(Op++, MD);
517 // Count the unresolved operands. If there are any, RAUW support will be
518 // added lazily on first reference.
519 countUnresolvedOperands();
522 TempMDNode MDNode::clone() const {
523 switch (getMetadataID()) {
525 llvm_unreachable("Invalid MDNode subclass");
526 #define HANDLE_MDNODE_LEAF(CLASS) \
528 return cast<CLASS>(this)->cloneImpl();
529 #include "llvm/IR/Metadata.def"
533 static bool isOperandUnresolved(Metadata *Op) {
534 if (auto *N = dyn_cast_or_null<MDNode>(Op))
535 return !N->isResolved();
539 void MDNode::countUnresolvedOperands() {
540 assert(NumUnresolved == 0 && "Expected unresolved ops to be uncounted");
541 assert(isUniqued() && "Expected this to be uniqued");
542 NumUnresolved = count_if(operands(), isOperandUnresolved);
545 void MDNode::makeUniqued() {
546 assert(isTemporary() && "Expected this to be temporary");
547 assert(!isResolved() && "Expected this to be unresolved");
549 // Enable uniquing callbacks.
550 for (auto &Op : mutable_operands())
551 Op.reset(Op.get(), this);
553 // Make this 'uniqued'.
555 countUnresolvedOperands();
556 if (!NumUnresolved) {
557 dropReplaceableUses();
558 assert(isResolved() && "Expected this to be resolved");
561 assert(isUniqued() && "Expected this to be uniqued");
564 void MDNode::makeDistinct() {
565 assert(isTemporary() && "Expected this to be temporary");
566 assert(!isResolved() && "Expected this to be unresolved");
568 // Drop RAUW support and store as a distinct node.
569 dropReplaceableUses();
570 storeDistinctInContext();
572 assert(isDistinct() && "Expected this to be distinct");
573 assert(isResolved() && "Expected this to be resolved");
576 void MDNode::resolve() {
577 assert(isUniqued() && "Expected this to be uniqued");
578 assert(!isResolved() && "Expected this to be unresolved");
581 dropReplaceableUses();
583 assert(isResolved() && "Expected this to be resolved");
586 void MDNode::dropReplaceableUses() {
587 assert(!NumUnresolved && "Unexpected unresolved operand");
589 // Drop any RAUW support.
590 if (Context.hasReplaceableUses())
591 Context.takeReplaceableUses()->resolveAllUses();
594 void MDNode::resolveAfterOperandChange(Metadata *Old, Metadata *New) {
595 assert(isUniqued() && "Expected this to be uniqued");
596 assert(NumUnresolved != 0 && "Expected unresolved operands");
598 // Check if an operand was resolved.
599 if (!isOperandUnresolved(Old)) {
600 if (isOperandUnresolved(New))
601 // An operand was un-resolved!
603 } else if (!isOperandUnresolved(New))
604 decrementUnresolvedOperandCount();
607 void MDNode::decrementUnresolvedOperandCount() {
608 assert(!isResolved() && "Expected this to be unresolved");
612 assert(isUniqued() && "Expected this to be uniqued");
616 // Last unresolved operand has just been resolved.
617 dropReplaceableUses();
618 assert(isResolved() && "Expected this to become resolved");
621 void MDNode::resolveCycles() {
625 // Resolve this node immediately.
628 // Resolve all operands.
629 for (const auto &Op : operands()) {
630 auto *N = dyn_cast_or_null<MDNode>(Op);
634 assert(!N->isTemporary() &&
635 "Expected all forward declarations to be resolved");
636 if (!N->isResolved())
641 static bool hasSelfReference(MDNode *N) {
642 for (Metadata *MD : N->operands())
648 MDNode *MDNode::replaceWithPermanentImpl() {
649 switch (getMetadataID()) {
651 // If this type isn't uniquable, replace with a distinct node.
652 return replaceWithDistinctImpl();
654 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS) \
657 #include "llvm/IR/Metadata.def"
660 // Even if this type is uniquable, self-references have to be distinct.
661 if (hasSelfReference(this))
662 return replaceWithDistinctImpl();
663 return replaceWithUniquedImpl();
666 MDNode *MDNode::replaceWithUniquedImpl() {
667 // Try to uniquify in place.
668 MDNode *UniquedNode = uniquify();
670 if (UniquedNode == this) {
675 // Collision, so RAUW instead.
676 replaceAllUsesWith(UniquedNode);
681 MDNode *MDNode::replaceWithDistinctImpl() {
686 void MDTuple::recalculateHash() {
687 setHash(MDTupleInfo::KeyTy::calculateHash(this));
690 void MDNode::dropAllReferences() {
691 for (unsigned I = 0, E = NumOperands; I != E; ++I)
692 setOperand(I, nullptr);
693 if (Context.hasReplaceableUses()) {
694 Context.getReplaceableUses()->resolveAllUses(/* ResolveUsers */ false);
695 (void)Context.takeReplaceableUses();
699 void MDNode::handleChangedOperand(void *Ref, Metadata *New) {
700 unsigned Op = static_cast<MDOperand *>(Ref) - op_begin();
701 assert(Op < getNumOperands() && "Expected valid operand");
704 // This node is not uniqued. Just set the operand and be done with it.
709 // This node is uniqued.
712 Metadata *Old = getOperand(Op);
715 // Drop uniquing for self-reference cycles and deleted constants.
716 if (New == this || (!New && Old && isa<ConstantAsMetadata>(Old))) {
719 storeDistinctInContext();
723 // Re-unique the node.
724 auto *Uniqued = uniquify();
725 if (Uniqued == this) {
727 resolveAfterOperandChange(Old, New);
733 // Still unresolved, so RAUW.
735 // First, clear out all operands to prevent any recursion (similar to
736 // dropAllReferences(), but we still need the use-list).
737 for (unsigned O = 0, E = getNumOperands(); O != E; ++O)
738 setOperand(O, nullptr);
739 if (Context.hasReplaceableUses())
740 Context.getReplaceableUses()->replaceAllUsesWith(Uniqued);
745 // Store in non-uniqued form if RAUW isn't possible.
746 storeDistinctInContext();
749 void MDNode::deleteAsSubclass() {
750 switch (getMetadataID()) {
752 llvm_unreachable("Invalid subclass of MDNode");
753 #define HANDLE_MDNODE_LEAF(CLASS) \
755 delete cast<CLASS>(this); \
757 #include "llvm/IR/Metadata.def"
761 template <class T, class InfoT>
762 static T *uniquifyImpl(T *N, DenseSet<T *, InfoT> &Store) {
763 if (T *U = getUniqued(Store, N))
770 template <class NodeTy> struct MDNode::HasCachedHash {
773 template <class U, U Val> struct SFINAE {};
776 static Yes &check(SFINAE<void (U::*)(unsigned), &U::setHash> *);
777 template <class U> static No &check(...);
779 static const bool value = sizeof(check<NodeTy>(nullptr)) == sizeof(Yes);
782 MDNode *MDNode::uniquify() {
783 assert(!hasSelfReference(this) && "Cannot uniquify a self-referencing node");
785 // Try to insert into uniquing store.
786 switch (getMetadataID()) {
788 llvm_unreachable("Invalid or non-uniquable subclass of MDNode");
789 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS) \
790 case CLASS##Kind: { \
791 CLASS *SubclassThis = cast<CLASS>(this); \
792 std::integral_constant<bool, HasCachedHash<CLASS>::value> \
793 ShouldRecalculateHash; \
794 dispatchRecalculateHash(SubclassThis, ShouldRecalculateHash); \
795 return uniquifyImpl(SubclassThis, getContext().pImpl->CLASS##s); \
797 #include "llvm/IR/Metadata.def"
801 void MDNode::eraseFromStore() {
802 switch (getMetadataID()) {
804 llvm_unreachable("Invalid or non-uniquable subclass of MDNode");
805 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS) \
807 getContext().pImpl->CLASS##s.erase(cast<CLASS>(this)); \
809 #include "llvm/IR/Metadata.def"
813 MDTuple *MDTuple::getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs,
814 StorageType Storage, bool ShouldCreate) {
816 if (Storage == Uniqued) {
817 MDTupleInfo::KeyTy Key(MDs);
818 if (auto *N = getUniqued(Context.pImpl->MDTuples, Key))
822 Hash = Key.getHash();
824 assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
827 return storeImpl(new (MDs.size()) MDTuple(Context, Storage, Hash, MDs),
828 Storage, Context.pImpl->MDTuples);
831 void MDNode::deleteTemporary(MDNode *N) {
832 assert(N->isTemporary() && "Expected temporary node");
833 N->replaceAllUsesWith(nullptr);
834 N->deleteAsSubclass();
837 void MDNode::storeDistinctInContext() {
838 assert(!Context.hasReplaceableUses() && "Unexpected replaceable uses");
839 assert(!NumUnresolved && "Unexpected unresolved nodes");
841 assert(isResolved() && "Expected this to be resolved");
844 switch (getMetadataID()) {
846 llvm_unreachable("Invalid subclass of MDNode");
847 #define HANDLE_MDNODE_LEAF(CLASS) \
848 case CLASS##Kind: { \
849 std::integral_constant<bool, HasCachedHash<CLASS>::value> ShouldResetHash; \
850 dispatchResetHash(cast<CLASS>(this), ShouldResetHash); \
853 #include "llvm/IR/Metadata.def"
856 getContext().pImpl->DistinctMDNodes.push_back(this);
859 void MDNode::replaceOperandWith(unsigned I, Metadata *New) {
860 if (getOperand(I) == New)
868 handleChangedOperand(mutable_begin() + I, New);
871 void MDNode::setOperand(unsigned I, Metadata *New) {
872 assert(I < NumOperands);
873 mutable_begin()[I].reset(New, isUniqued() ? this : nullptr);
876 /// Get a node or a self-reference that looks like it.
878 /// Special handling for finding self-references, for use by \a
879 /// MDNode::concatenate() and \a MDNode::intersect() to maintain behaviour from
880 /// when self-referencing nodes were still uniqued. If the first operand has
881 /// the same operands as \c Ops, return the first operand instead.
882 static MDNode *getOrSelfReference(LLVMContext &Context,
883 ArrayRef<Metadata *> Ops) {
885 if (MDNode *N = dyn_cast_or_null<MDNode>(Ops[0]))
886 if (N->getNumOperands() == Ops.size() && N == N->getOperand(0)) {
887 for (unsigned I = 1, E = Ops.size(); I != E; ++I)
888 if (Ops[I] != N->getOperand(I))
889 return MDNode::get(Context, Ops);
893 return MDNode::get(Context, Ops);
896 MDNode *MDNode::concatenate(MDNode *A, MDNode *B) {
902 SmallSetVector<Metadata *, 4> MDs(A->op_begin(), A->op_end());
903 MDs.insert(B->op_begin(), B->op_end());
905 // FIXME: This preserves long-standing behaviour, but is it really the right
906 // behaviour? Or was that an unintended side-effect of node uniquing?
907 return getOrSelfReference(A->getContext(), MDs.getArrayRef());
910 MDNode *MDNode::intersect(MDNode *A, MDNode *B) {
914 SmallSetVector<Metadata *, 4> MDs(A->op_begin(), A->op_end());
915 SmallPtrSet<Metadata *, 4> BSet(B->op_begin(), B->op_end());
916 MDs.remove_if([&](Metadata *MD) { return !is_contained(BSet, MD); });
918 // FIXME: This preserves long-standing behaviour, but is it really the right
919 // behaviour? Or was that an unintended side-effect of node uniquing?
920 return getOrSelfReference(A->getContext(), MDs.getArrayRef());
923 MDNode *MDNode::getMostGenericAliasScope(MDNode *A, MDNode *B) {
927 return concatenate(A, B);
930 MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
934 APFloat AVal = mdconst::extract<ConstantFP>(A->getOperand(0))->getValueAPF();
935 APFloat BVal = mdconst::extract<ConstantFP>(B->getOperand(0))->getValueAPF();
936 if (AVal.compare(BVal) == APFloat::cmpLessThan)
941 static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
942 return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
945 static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
946 return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
949 static bool tryMergeRange(SmallVectorImpl<ConstantInt *> &EndPoints,
950 ConstantInt *Low, ConstantInt *High) {
951 ConstantRange NewRange(Low->getValue(), High->getValue());
952 unsigned Size = EndPoints.size();
953 APInt LB = EndPoints[Size - 2]->getValue();
954 APInt LE = EndPoints[Size - 1]->getValue();
955 ConstantRange LastRange(LB, LE);
956 if (canBeMerged(NewRange, LastRange)) {
957 ConstantRange Union = LastRange.unionWith(NewRange);
958 Type *Ty = High->getType();
959 EndPoints[Size - 2] =
960 cast<ConstantInt>(ConstantInt::get(Ty, Union.getLower()));
961 EndPoints[Size - 1] =
962 cast<ConstantInt>(ConstantInt::get(Ty, Union.getUpper()));
968 static void addRange(SmallVectorImpl<ConstantInt *> &EndPoints,
969 ConstantInt *Low, ConstantInt *High) {
970 if (!EndPoints.empty())
971 if (tryMergeRange(EndPoints, Low, High))
974 EndPoints.push_back(Low);
975 EndPoints.push_back(High);
978 MDNode *MDNode::getMostGenericRange(MDNode *A, MDNode *B) {
979 // Given two ranges, we want to compute the union of the ranges. This
980 // is slightly complicated by having to combine the intervals and merge
981 // the ones that overlap.
989 // First, walk both lists in order of the lower boundary of each interval.
990 // At each step, try to merge the new interval to the last one we adedd.
991 SmallVector<ConstantInt *, 4> EndPoints;
994 int AN = A->getNumOperands() / 2;
995 int BN = B->getNumOperands() / 2;
996 while (AI < AN && BI < BN) {
997 ConstantInt *ALow = mdconst::extract<ConstantInt>(A->getOperand(2 * AI));
998 ConstantInt *BLow = mdconst::extract<ConstantInt>(B->getOperand(2 * BI));
1000 if (ALow->getValue().slt(BLow->getValue())) {
1001 addRange(EndPoints, ALow,
1002 mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
1005 addRange(EndPoints, BLow,
1006 mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
1011 addRange(EndPoints, mdconst::extract<ConstantInt>(A->getOperand(2 * AI)),
1012 mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
1016 addRange(EndPoints, mdconst::extract<ConstantInt>(B->getOperand(2 * BI)),
1017 mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
1021 // If we have more than 2 ranges (4 endpoints) we have to try to merge
1022 // the last and first ones.
1023 unsigned Size = EndPoints.size();
1025 ConstantInt *FB = EndPoints[0];
1026 ConstantInt *FE = EndPoints[1];
1027 if (tryMergeRange(EndPoints, FB, FE)) {
1028 for (unsigned i = 0; i < Size - 2; ++i) {
1029 EndPoints[i] = EndPoints[i + 2];
1031 EndPoints.resize(Size - 2);
1035 // If in the end we have a single range, it is possible that it is now the
1036 // full range. Just drop the metadata in that case.
1037 if (EndPoints.size() == 2) {
1038 ConstantRange Range(EndPoints[0]->getValue(), EndPoints[1]->getValue());
1039 if (Range.isFullSet())
1043 SmallVector<Metadata *, 4> MDs;
1044 MDs.reserve(EndPoints.size());
1045 for (auto *I : EndPoints)
1046 MDs.push_back(ConstantAsMetadata::get(I));
1047 return MDNode::get(A->getContext(), MDs);
1050 MDNode *MDNode::getMostGenericAlignmentOrDereferenceable(MDNode *A, MDNode *B) {
1054 ConstantInt *AVal = mdconst::extract<ConstantInt>(A->getOperand(0));
1055 ConstantInt *BVal = mdconst::extract<ConstantInt>(B->getOperand(0));
1056 if (AVal->getZExtValue() < BVal->getZExtValue())
1061 //===----------------------------------------------------------------------===//
1062 // NamedMDNode implementation.
1065 static SmallVector<TrackingMDRef, 4> &getNMDOps(void *Operands) {
1066 return *(SmallVector<TrackingMDRef, 4> *)Operands;
1069 NamedMDNode::NamedMDNode(const Twine &N)
1070 : Name(N.str()), Operands(new SmallVector<TrackingMDRef, 4>()) {}
1072 NamedMDNode::~NamedMDNode() {
1073 dropAllReferences();
1074 delete &getNMDOps(Operands);
1077 unsigned NamedMDNode::getNumOperands() const {
1078 return (unsigned)getNMDOps(Operands).size();
1081 MDNode *NamedMDNode::getOperand(unsigned i) const {
1082 assert(i < getNumOperands() && "Invalid Operand number!");
1083 auto *N = getNMDOps(Operands)[i].get();
1084 return cast_or_null<MDNode>(N);
1087 void NamedMDNode::addOperand(MDNode *M) { getNMDOps(Operands).emplace_back(M); }
1089 void NamedMDNode::setOperand(unsigned I, MDNode *New) {
1090 assert(I < getNumOperands() && "Invalid operand number");
1091 getNMDOps(Operands)[I].reset(New);
1094 void NamedMDNode::eraseFromParent() { getParent()->eraseNamedMetadata(this); }
1096 void NamedMDNode::clearOperands() { getNMDOps(Operands).clear(); }
1098 StringRef NamedMDNode::getName() const { return StringRef(Name); }
1100 //===----------------------------------------------------------------------===//
1101 // Instruction Metadata method implementations.
1103 void MDAttachmentMap::set(unsigned ID, MDNode &MD) {
1104 for (auto &I : Attachments)
1105 if (I.first == ID) {
1106 I.second.reset(&MD);
1109 Attachments.emplace_back(std::piecewise_construct, std::make_tuple(ID),
1110 std::make_tuple(&MD));
1113 bool MDAttachmentMap::erase(unsigned ID) {
1117 // Common case is one/last value.
1118 if (Attachments.back().first == ID) {
1119 Attachments.pop_back();
1123 for (auto I = Attachments.begin(), E = std::prev(Attachments.end()); I != E;
1125 if (I->first == ID) {
1126 *I = std::move(Attachments.back());
1127 Attachments.pop_back();
1134 MDNode *MDAttachmentMap::lookup(unsigned ID) const {
1135 for (const auto &I : Attachments)
1141 void MDAttachmentMap::getAll(
1142 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1143 Result.append(Attachments.begin(), Attachments.end());
1145 // Sort the resulting array so it is stable.
1146 if (Result.size() > 1)
1147 array_pod_sort(Result.begin(), Result.end());
1150 void MDGlobalAttachmentMap::insert(unsigned ID, MDNode &MD) {
1151 Attachments.push_back({ID, TrackingMDNodeRef(&MD)});
1154 MDNode *MDGlobalAttachmentMap::lookup(unsigned ID) const {
1155 for (const auto &A : Attachments)
1161 void MDGlobalAttachmentMap::get(unsigned ID,
1162 SmallVectorImpl<MDNode *> &Result) const {
1163 for (const auto &A : Attachments)
1165 Result.push_back(A.Node);
1168 bool MDGlobalAttachmentMap::erase(unsigned ID) {
1169 auto I = std::remove_if(Attachments.begin(), Attachments.end(),
1170 [ID](const Attachment &A) { return A.MDKind == ID; });
1171 bool Changed = I != Attachments.end();
1172 Attachments.erase(I, Attachments.end());
1176 void MDGlobalAttachmentMap::getAll(
1177 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1178 for (const auto &A : Attachments)
1179 Result.emplace_back(A.MDKind, A.Node);
1181 // Sort the resulting array so it is stable with respect to metadata IDs. We
1182 // need to preserve the original insertion order though.
1184 Result.begin(), Result.end(),
1185 [](const std::pair<unsigned, MDNode *> &A,
1186 const std::pair<unsigned, MDNode *> &B) { return A.first < B.first; });
1189 void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
1190 if (!Node && !hasMetadata())
1192 setMetadata(getContext().getMDKindID(Kind), Node);
1195 MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
1196 return getMetadataImpl(getContext().getMDKindID(Kind));
1199 void Instruction::dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs) {
1200 if (!hasMetadataHashEntry())
1201 return; // Nothing to remove!
1203 auto &InstructionMetadata = getContext().pImpl->InstructionMetadata;
1205 SmallSet<unsigned, 4> KnownSet;
1206 KnownSet.insert(KnownIDs.begin(), KnownIDs.end());
1207 if (KnownSet.empty()) {
1208 // Just drop our entry at the store.
1209 InstructionMetadata.erase(this);
1210 setHasMetadataHashEntry(false);
1214 auto &Info = InstructionMetadata[this];
1215 Info.remove_if([&KnownSet](const std::pair<unsigned, TrackingMDNodeRef> &I) {
1216 return !KnownSet.count(I.first);
1220 // Drop our entry at the store.
1221 InstructionMetadata.erase(this);
1222 setHasMetadataHashEntry(false);
1226 void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
1227 if (!Node && !hasMetadata())
1230 // Handle 'dbg' as a special case since it is not stored in the hash table.
1231 if (KindID == LLVMContext::MD_dbg) {
1232 DbgLoc = DebugLoc(Node);
1236 // Handle the case when we're adding/updating metadata on an instruction.
1238 auto &Info = getContext().pImpl->InstructionMetadata[this];
1239 assert(!Info.empty() == hasMetadataHashEntry() &&
1240 "HasMetadata bit is wonked");
1242 setHasMetadataHashEntry(true);
1243 Info.set(KindID, *Node);
1247 // Otherwise, we're removing metadata from an instruction.
1248 assert((hasMetadataHashEntry() ==
1249 (getContext().pImpl->InstructionMetadata.count(this) > 0)) &&
1250 "HasMetadata bit out of date!");
1251 if (!hasMetadataHashEntry())
1252 return; // Nothing to remove!
1253 auto &Info = getContext().pImpl->InstructionMetadata[this];
1255 // Handle removal of an existing value.
1261 getContext().pImpl->InstructionMetadata.erase(this);
1262 setHasMetadataHashEntry(false);
1265 void Instruction::setAAMetadata(const AAMDNodes &N) {
1266 setMetadata(LLVMContext::MD_tbaa, N.TBAA);
1267 setMetadata(LLVMContext::MD_alias_scope, N.Scope);
1268 setMetadata(LLVMContext::MD_noalias, N.NoAlias);
1271 MDNode *Instruction::getMetadataImpl(unsigned KindID) const {
1272 // Handle 'dbg' as a special case since it is not stored in the hash table.
1273 if (KindID == LLVMContext::MD_dbg)
1274 return DbgLoc.getAsMDNode();
1276 if (!hasMetadataHashEntry())
1278 auto &Info = getContext().pImpl->InstructionMetadata[this];
1279 assert(!Info.empty() && "bit out of sync with hash table");
1281 return Info.lookup(KindID);
1284 void Instruction::getAllMetadataImpl(
1285 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1288 // Handle 'dbg' as a special case since it is not stored in the hash table.
1291 std::make_pair((unsigned)LLVMContext::MD_dbg, DbgLoc.getAsMDNode()));
1292 if (!hasMetadataHashEntry())
1296 assert(hasMetadataHashEntry() &&
1297 getContext().pImpl->InstructionMetadata.count(this) &&
1298 "Shouldn't have called this");
1299 const auto &Info = getContext().pImpl->InstructionMetadata.find(this)->second;
1300 assert(!Info.empty() && "Shouldn't have called this");
1301 Info.getAll(Result);
1304 void Instruction::getAllMetadataOtherThanDebugLocImpl(
1305 SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1307 assert(hasMetadataHashEntry() &&
1308 getContext().pImpl->InstructionMetadata.count(this) &&
1309 "Shouldn't have called this");
1310 const auto &Info = getContext().pImpl->InstructionMetadata.find(this)->second;
1311 assert(!Info.empty() && "Shouldn't have called this");
1312 Info.getAll(Result);
1315 bool Instruction::extractProfMetadata(uint64_t &TrueVal,
1316 uint64_t &FalseVal) const {
1318 (getOpcode() == Instruction::Br || getOpcode() == Instruction::Select) &&
1319 "Looking for branch weights on something besides branch or select");
1321 auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1322 if (!ProfileData || ProfileData->getNumOperands() != 3)
1325 auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1326 if (!ProfDataName || !ProfDataName->getString().equals("branch_weights"))
1329 auto *CITrue = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1));
1330 auto *CIFalse = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2));
1331 if (!CITrue || !CIFalse)
1334 TrueVal = CITrue->getValue().getZExtValue();
1335 FalseVal = CIFalse->getValue().getZExtValue();
1340 bool Instruction::extractProfTotalWeight(uint64_t &TotalVal) const {
1341 assert((getOpcode() == Instruction::Br ||
1342 getOpcode() == Instruction::Select ||
1343 getOpcode() == Instruction::Call ||
1344 getOpcode() == Instruction::Invoke ||
1345 getOpcode() == Instruction::Switch) &&
1346 "Looking for branch weights on something besides branch");
1349 auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1353 auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1357 if (ProfDataName->getString().equals("branch_weights")) {
1359 for (unsigned i = 1; i < ProfileData->getNumOperands(); i++) {
1360 auto *V = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i));
1363 TotalVal += V->getValue().getZExtValue();
1366 } else if (ProfDataName->getString().equals("VP") &&
1367 ProfileData->getNumOperands() > 3) {
1368 TotalVal = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2))
1376 void Instruction::clearMetadataHashEntries() {
1377 assert(hasMetadataHashEntry() && "Caller should check");
1378 getContext().pImpl->InstructionMetadata.erase(this);
1379 setHasMetadataHashEntry(false);
1382 void GlobalObject::getMetadata(unsigned KindID,
1383 SmallVectorImpl<MDNode *> &MDs) const {
1385 getContext().pImpl->GlobalObjectMetadata[this].get(KindID, MDs);
1388 void GlobalObject::getMetadata(StringRef Kind,
1389 SmallVectorImpl<MDNode *> &MDs) const {
1391 getMetadata(getContext().getMDKindID(Kind), MDs);
1394 void GlobalObject::addMetadata(unsigned KindID, MDNode &MD) {
1396 setHasMetadataHashEntry(true);
1398 getContext().pImpl->GlobalObjectMetadata[this].insert(KindID, MD);
1401 void GlobalObject::addMetadata(StringRef Kind, MDNode &MD) {
1402 addMetadata(getContext().getMDKindID(Kind), MD);
1405 bool GlobalObject::eraseMetadata(unsigned KindID) {
1406 // Nothing to unset.
1410 auto &Store = getContext().pImpl->GlobalObjectMetadata[this];
1411 bool Changed = Store.erase(KindID);
1417 void GlobalObject::getAllMetadata(
1418 SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
1424 getContext().pImpl->GlobalObjectMetadata[this].getAll(MDs);
1427 void GlobalObject::clearMetadata() {
1430 getContext().pImpl->GlobalObjectMetadata.erase(this);
1431 setHasMetadataHashEntry(false);
1434 void GlobalObject::setMetadata(unsigned KindID, MDNode *N) {
1435 eraseMetadata(KindID);
1437 addMetadata(KindID, *N);
1440 void GlobalObject::setMetadata(StringRef Kind, MDNode *N) {
1441 setMetadata(getContext().getMDKindID(Kind), N);
1444 MDNode *GlobalObject::getMetadata(unsigned KindID) const {
1446 return getContext().pImpl->GlobalObjectMetadata[this].lookup(KindID);
1450 MDNode *GlobalObject::getMetadata(StringRef Kind) const {
1451 return getMetadata(getContext().getMDKindID(Kind));
1454 void GlobalObject::copyMetadata(const GlobalObject *Other, unsigned Offset) {
1455 SmallVector<std::pair<unsigned, MDNode *>, 8> MDs;
1456 Other->getAllMetadata(MDs);
1457 for (auto &MD : MDs) {
1458 // We need to adjust the type metadata offset.
1459 if (Offset != 0 && MD.first == LLVMContext::MD_type) {
1460 auto *OffsetConst = cast<ConstantInt>(
1461 cast<ConstantAsMetadata>(MD.second->getOperand(0))->getValue());
1462 Metadata *TypeId = MD.second->getOperand(1);
1463 auto *NewOffsetMD = ConstantAsMetadata::get(ConstantInt::get(
1464 OffsetConst->getType(), OffsetConst->getValue() + Offset));
1465 addMetadata(LLVMContext::MD_type,
1466 *MDNode::get(getContext(), {NewOffsetMD, TypeId}));
1469 // If an offset adjustment was specified we need to modify the DIExpression
1470 // to prepend the adjustment:
1471 // !DIExpression(DW_OP_plus, Offset, [original expr])
1472 auto *Attachment = MD.second;
1473 if (Offset != 0 && MD.first == LLVMContext::MD_dbg) {
1474 DIGlobalVariable *GV = dyn_cast<DIGlobalVariable>(Attachment);
1475 DIExpression *E = nullptr;
1477 auto *GVE = cast<DIGlobalVariableExpression>(Attachment);
1478 GV = GVE->getVariable();
1479 E = GVE->getExpression();
1481 ArrayRef<uint64_t> OrigElements;
1483 OrigElements = E->getElements();
1484 std::vector<uint64_t> Elements(OrigElements.size() + 2);
1485 Elements[0] = dwarf::DW_OP_plus_uconst;
1486 Elements[1] = Offset;
1487 std::copy(OrigElements.begin(), OrigElements.end(), Elements.begin() + 2);
1488 E = DIExpression::get(getContext(), Elements);
1489 Attachment = DIGlobalVariableExpression::get(getContext(), GV, E);
1491 addMetadata(MD.first, *Attachment);
1495 void GlobalObject::addTypeMetadata(unsigned Offset, Metadata *TypeID) {
1497 LLVMContext::MD_type,
1498 *MDTuple::get(getContext(),
1499 {ConstantAsMetadata::get(ConstantInt::get(
1500 Type::getInt64Ty(getContext()), Offset)),
1504 void Function::setSubprogram(DISubprogram *SP) {
1505 setMetadata(LLVMContext::MD_dbg, SP);
1508 DISubprogram *Function::getSubprogram() const {
1509 return cast_or_null<DISubprogram>(getMetadata(LLVMContext::MD_dbg));
1512 bool Function::isDebugInfoForProfiling() const {
1513 if (DISubprogram *SP = getSubprogram()) {
1514 if (DICompileUnit *CU = SP->getUnit()) {
1515 return CU->getDebugInfoForProfiling();
1521 void GlobalVariable::addDebugInfo(DIGlobalVariableExpression *GV) {
1522 addMetadata(LLVMContext::MD_dbg, *GV);
1525 void GlobalVariable::getDebugInfo(
1526 SmallVectorImpl<DIGlobalVariableExpression *> &GVs) const {
1527 SmallVector<MDNode *, 1> MDs;
1528 getMetadata(LLVMContext::MD_dbg, MDs);
1529 for (MDNode *MD : MDs)
1530 GVs.push_back(cast<DIGlobalVariableExpression>(MD));