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1 //===- Metadata.cpp - Implement Metadata classes --------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the Metadata classes.
11 //
12 //===----------------------------------------------------------------------===//
13 
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"
51 #include <algorithm>
52 #include <cassert>
53 #include <cstddef>
54 #include <cstdint>
55 #include <iterator>
56 #include <tuple>
57 #include <type_traits>
58 #include <utility>
59 #include <vector>
60 
61 using namespace llvm;
62 
MetadataAsValue(Type * Ty,Metadata * MD)63 MetadataAsValue::MetadataAsValue(Type *Ty, Metadata *MD)
64     : Value(Ty, MetadataAsValueVal), MD(MD) {
65   track();
66 }
67 
~MetadataAsValue()68 MetadataAsValue::~MetadataAsValue() {
69   getType()->getContext().pImpl->MetadataAsValues.erase(MD);
70   untrack();
71 }
72 
73 /// Canonicalize metadata arguments to intrinsics.
74 ///
75 /// To support bitcode upgrades (and assembly semantic sugar) for \a
76 /// MetadataAsValue, we need to canonicalize certain metadata.
77 ///
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.
81 ///
82 /// This maintains readability of bitcode from when metadata was a type of
83 /// value, and these bridges were unnecessary.
canonicalizeMetadataForValue(LLVMContext & Context,Metadata * MD)84 static Metadata *canonicalizeMetadataForValue(LLVMContext &Context,
85                                               Metadata *MD) {
86   if (!MD)
87     // !{}
88     return MDNode::get(Context, None);
89 
90   // Return early if this isn't a single-operand MDNode.
91   auto *N = dyn_cast<MDNode>(MD);
92   if (!N || N->getNumOperands() != 1)
93     return MD;
94 
95   if (!N->getOperand(0))
96     // !{}
97     return MDNode::get(Context, None);
98 
99   if (auto *C = dyn_cast<ConstantAsMetadata>(N->getOperand(0)))
100     // Look through the MDNode.
101     return C;
102 
103   return MD;
104 }
105 
get(LLVMContext & Context,Metadata * MD)106 MetadataAsValue *MetadataAsValue::get(LLVMContext &Context, Metadata *MD) {
107   MD = canonicalizeMetadataForValue(Context, MD);
108   auto *&Entry = Context.pImpl->MetadataAsValues[MD];
109   if (!Entry)
110     Entry = new MetadataAsValue(Type::getMetadataTy(Context), MD);
111   return Entry;
112 }
113 
getIfExists(LLVMContext & Context,Metadata * MD)114 MetadataAsValue *MetadataAsValue::getIfExists(LLVMContext &Context,
115                                               Metadata *MD) {
116   MD = canonicalizeMetadataForValue(Context, MD);
117   auto &Store = Context.pImpl->MetadataAsValues;
118   return Store.lookup(MD);
119 }
120 
handleChangedMetadata(Metadata * MD)121 void MetadataAsValue::handleChangedMetadata(Metadata *MD) {
122   LLVMContext &Context = getContext();
123   MD = canonicalizeMetadataForValue(Context, MD);
124   auto &Store = Context.pImpl->MetadataAsValues;
125 
126   // Stop tracking the old metadata.
127   Store.erase(this->MD);
128   untrack();
129   this->MD = nullptr;
130 
131   // Start tracking MD, or RAUW if necessary.
132   auto *&Entry = Store[MD];
133   if (Entry) {
134     replaceAllUsesWith(Entry);
135     delete this;
136     return;
137   }
138 
139   this->MD = MD;
140   track();
141   Entry = this;
142 }
143 
track()144 void MetadataAsValue::track() {
145   if (MD)
146     MetadataTracking::track(&MD, *MD, *this);
147 }
148 
untrack()149 void MetadataAsValue::untrack() {
150   if (MD)
151     MetadataTracking::untrack(MD);
152 }
153 
track(void * Ref,Metadata & MD,OwnerTy Owner)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);
160     return true;
161   }
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);
166     return true;
167   }
168   return false;
169 }
170 
untrack(void * Ref,Metadata & MD)171 void MetadataTracking::untrack(void *Ref, Metadata &MD) {
172   assert(Ref && "Expected live reference");
173   if (auto *R = ReplaceableMetadataImpl::getIfExists(MD))
174     R->dropRef(Ref);
175   else if (auto *PH = dyn_cast<DistinctMDOperandPlaceholder>(&MD))
176     PH->Use = nullptr;
177 }
178 
retrack(void * Ref,Metadata & MD,void * New)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);
185     return true;
186   }
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");
191   return false;
192 }
193 
isReplaceable(const Metadata & MD)194 bool MetadataTracking::isReplaceable(const Metadata &MD) {
195   return ReplaceableMetadataImpl::isReplaceable(MD);
196 }
197 
addRef(void * Ref,OwnerTy Owner)198 void ReplaceableMetadataImpl::addRef(void *Ref, OwnerTy Owner) {
199   bool WasInserted =
200       UseMap.insert(std::make_pair(Ref, std::make_pair(Owner, NextIndex)))
201           .second;
202   (void)WasInserted;
203   assert(WasInserted && "Expected to add a reference");
204 
205   ++NextIndex;
206   assert(NextIndex != 0 && "Unexpected overflow");
207 }
208 
dropRef(void * Ref)209 void ReplaceableMetadataImpl::dropRef(void *Ref) {
210   bool WasErased = UseMap.erase(Ref);
211   (void)WasErased;
212   assert(WasErased && "Expected to drop a reference");
213 }
214 
moveRef(void * Ref,void * New,const Metadata & MD)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;
220   UseMap.erase(I);
221   bool WasInserted = UseMap.insert(std::make_pair(New, OwnerAndIndex)).second;
222   (void)WasInserted;
223   assert(WasInserted && "Expected to add a reference");
224 
225   // Check that the references are direct if there's no owner.
226   (void)MD;
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");
231 }
232 
replaceAllUsesWith(Metadata * MD)233 void ReplaceableMetadataImpl::replaceAllUsesWith(Metadata *MD) {
234   if (UseMap.empty())
235     return;
236 
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;
242   });
243   for (const auto &Pair : Uses) {
244     // Check that this Ref hasn't disappeared after RAUW (when updating a
245     // previous Ref).
246     if (!UseMap.count(Pair.first))
247       continue;
248 
249     OwnerTy Owner = Pair.second.first;
250     if (!Owner) {
251       // Update unowned tracking references directly.
252       Metadata *&Ref = *static_cast<Metadata **>(Pair.first);
253       Ref = MD;
254       if (MD)
255         MetadataTracking::track(Ref);
256       UseMap.erase(Pair.first);
257       continue;
258     }
259 
260     // Check for MetadataAsValue.
261     if (Owner.is<MetadataAsValue *>()) {
262       Owner.get<MetadataAsValue *>()->handleChangedMetadata(MD);
263       continue;
264     }
265 
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);                \
272     continue;
273 #include "llvm/IR/Metadata.def"
274     default:
275       llvm_unreachable("Invalid metadata subclass");
276     }
277   }
278   assert(UseMap.empty() && "Expected all uses to be replaced");
279 }
280 
resolveAllUses(bool ResolveUsers)281 void ReplaceableMetadataImpl::resolveAllUses(bool ResolveUsers) {
282   if (UseMap.empty())
283     return;
284 
285   if (!ResolveUsers) {
286     UseMap.clear();
287     return;
288   }
289 
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;
295   });
296   UseMap.clear();
297   for (const auto &Pair : Uses) {
298     auto Owner = Pair.second.first;
299     if (!Owner)
300       continue;
301     if (Owner.is<MetadataAsValue *>())
302       continue;
303 
304     // Resolve MDNodes that point at this.
305     auto *OwnerMD = dyn_cast<MDNode>(Owner.get<Metadata *>());
306     if (!OwnerMD)
307       continue;
308     if (OwnerMD->isResolved())
309       continue;
310     OwnerMD->decrementUnresolvedOperandCount();
311   }
312 }
313 
getOrCreate(Metadata & MD)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);
318 }
319 
getIfExists(Metadata & 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);
324 }
325 
isReplaceable(const Metadata & 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);
330 }
331 
getLocalFunctionMetadata(Value * V)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();
337     return nullptr;
338   }
339 
340   if (BasicBlock *BB = cast<Instruction>(V)->getParent()) {
341     if (auto *Fn = BB->getParent())
342       return Fn->getSubprogram();
343     return nullptr;
344   }
345 
346   return nullptr;
347 }
348 
get(Value * V)349 ValueAsMetadata *ValueAsMetadata::get(Value *V) {
350   assert(V && "Unexpected null Value");
351 
352   auto &Context = V->getContext();
353   auto *&Entry = Context.pImpl->ValuesAsMetadata[V];
354   if (!Entry) {
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);
361     else
362       Entry = new LocalAsMetadata(V);
363   }
364 
365   return Entry;
366 }
367 
getIfExists(Value * V)368 ValueAsMetadata *ValueAsMetadata::getIfExists(Value *V) {
369   assert(V && "Unexpected null Value");
370   return V->getContext().pImpl->ValuesAsMetadata.lookup(V);
371 }
372 
handleDeletion(Value * V)373 void ValueAsMetadata::handleDeletion(Value *V) {
374   assert(V && "Expected valid value");
375 
376   auto &Store = V->getType()->getContext().pImpl->ValuesAsMetadata;
377   auto I = Store.find(V);
378   if (I == Store.end())
379     return;
380 
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");
385   Store.erase(I);
386 
387   // Delete the metadata.
388   MD->replaceAllUsesWith(nullptr);
389   delete MD;
390 }
391 
handleRAUW(Value * From,Value * To)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");
397 
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");
403     return;
404   }
405 
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");
412   Store.erase(I);
413 
414   if (isa<LocalAsMetadata>(MD)) {
415     if (auto *C = dyn_cast<Constant>(To)) {
416       // Local became a constant.
417       MD->replaceAllUsesWith(ConstantAsMetadata::get(C));
418       delete MD;
419       return;
420     }
421     if (getLocalFunctionMetadata(From) && getLocalFunctionMetadata(To) &&
422         getLocalFunctionMetadata(From) != getLocalFunctionMetadata(To)) {
423       // DISubprogram changed.
424       MD->replaceAllUsesWith(nullptr);
425       delete MD;
426       return;
427     }
428   } else if (!isa<Constant>(To)) {
429     // Changed to function-local value.
430     MD->replaceAllUsesWith(nullptr);
431     delete MD;
432     return;
433   }
434 
435   auto *&Entry = Store[To];
436   if (Entry) {
437     // The target already exists.
438     MD->replaceAllUsesWith(Entry);
439     delete MD;
440     return;
441   }
442 
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;
446   MD->V = To;
447   Entry = MD;
448 }
449 
450 //===----------------------------------------------------------------------===//
451 // MDString implementation.
452 //
453 
get(LLVMContext & Context,StringRef Str)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();
458   if (!I.second)
459     return &MapEntry;
460   MapEntry.Entry = &*I.first;
461   return &MapEntry;
462 }
463 
getString() const464 StringRef MDString::getString() const {
465   assert(Entry && "Expected to find string map entry");
466   return Entry->first();
467 }
468 
469 //===----------------------------------------------------------------------===//
470 // MDNode implementation.
471 //
472 
473 // Assert that the MDNode types will not be unaligned by the objects
474 // prepended to them.
475 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
476   static_assert(                                                               \
477       alignof(uint64_t) >= alignof(CLASS),                                     \
478       "Alignment is insufficient after objects prepended to " #CLASS);
479 #include "llvm/IR/Metadata.def"
480 
operator new(size_t Size,unsigned NumOps)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
484   // above)
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;
490   return Ptr;
491 }
492 
operator delete(void * Mem)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));
497 
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);
502 }
503 
MDNode(LLVMContext & Context,unsigned ID,StorageType Storage,ArrayRef<Metadata * > Ops1,ArrayRef<Metadata * > Ops2)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) {
508   unsigned Op = 0;
509   for (Metadata *MD : Ops1)
510     setOperand(Op++, MD);
511   for (Metadata *MD : Ops2)
512     setOperand(Op++, MD);
513 
514   if (!isUniqued())
515     return;
516 
517   // Count the unresolved operands.  If there are any, RAUW support will be
518   // added lazily on first reference.
519   countUnresolvedOperands();
520 }
521 
clone() const522 TempMDNode MDNode::clone() const {
523   switch (getMetadataID()) {
524   default:
525     llvm_unreachable("Invalid MDNode subclass");
526 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
527   case CLASS##Kind:                                                            \
528     return cast<CLASS>(this)->cloneImpl();
529 #include "llvm/IR/Metadata.def"
530   }
531 }
532 
isOperandUnresolved(Metadata * Op)533 static bool isOperandUnresolved(Metadata *Op) {
534   if (auto *N = dyn_cast_or_null<MDNode>(Op))
535     return !N->isResolved();
536   return false;
537 }
538 
countUnresolvedOperands()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);
543 }
544 
makeUniqued()545 void MDNode::makeUniqued() {
546   assert(isTemporary() && "Expected this to be temporary");
547   assert(!isResolved() && "Expected this to be unresolved");
548 
549   // Enable uniquing callbacks.
550   for (auto &Op : mutable_operands())
551     Op.reset(Op.get(), this);
552 
553   // Make this 'uniqued'.
554   Storage = Uniqued;
555   countUnresolvedOperands();
556   if (!NumUnresolved) {
557     dropReplaceableUses();
558     assert(isResolved() && "Expected this to be resolved");
559   }
560 
561   assert(isUniqued() && "Expected this to be uniqued");
562 }
563 
makeDistinct()564 void MDNode::makeDistinct() {
565   assert(isTemporary() && "Expected this to be temporary");
566   assert(!isResolved() && "Expected this to be unresolved");
567 
568   // Drop RAUW support and store as a distinct node.
569   dropReplaceableUses();
570   storeDistinctInContext();
571 
572   assert(isDistinct() && "Expected this to be distinct");
573   assert(isResolved() && "Expected this to be resolved");
574 }
575 
resolve()576 void MDNode::resolve() {
577   assert(isUniqued() && "Expected this to be uniqued");
578   assert(!isResolved() && "Expected this to be unresolved");
579 
580   NumUnresolved = 0;
581   dropReplaceableUses();
582 
583   assert(isResolved() && "Expected this to be resolved");
584 }
585 
dropReplaceableUses()586 void MDNode::dropReplaceableUses() {
587   assert(!NumUnresolved && "Unexpected unresolved operand");
588 
589   // Drop any RAUW support.
590   if (Context.hasReplaceableUses())
591     Context.takeReplaceableUses()->resolveAllUses();
592 }
593 
resolveAfterOperandChange(Metadata * Old,Metadata * New)594 void MDNode::resolveAfterOperandChange(Metadata *Old, Metadata *New) {
595   assert(isUniqued() && "Expected this to be uniqued");
596   assert(NumUnresolved != 0 && "Expected unresolved operands");
597 
598   // Check if an operand was resolved.
599   if (!isOperandUnresolved(Old)) {
600     if (isOperandUnresolved(New))
601       // An operand was un-resolved!
602       ++NumUnresolved;
603   } else if (!isOperandUnresolved(New))
604     decrementUnresolvedOperandCount();
605 }
606 
decrementUnresolvedOperandCount()607 void MDNode::decrementUnresolvedOperandCount() {
608   assert(!isResolved() && "Expected this to be unresolved");
609   if (isTemporary())
610     return;
611 
612   assert(isUniqued() && "Expected this to be uniqued");
613   if (--NumUnresolved)
614     return;
615 
616   // Last unresolved operand has just been resolved.
617   dropReplaceableUses();
618   assert(isResolved() && "Expected this to become resolved");
619 }
620 
resolveCycles()621 void MDNode::resolveCycles() {
622   if (isResolved())
623     return;
624 
625   // Resolve this node immediately.
626   resolve();
627 
628   // Resolve all operands.
629   for (const auto &Op : operands()) {
630     auto *N = dyn_cast_or_null<MDNode>(Op);
631     if (!N)
632       continue;
633 
634     assert(!N->isTemporary() &&
635            "Expected all forward declarations to be resolved");
636     if (!N->isResolved())
637       N->resolveCycles();
638   }
639 }
640 
hasSelfReference(MDNode * N)641 static bool hasSelfReference(MDNode *N) {
642   for (Metadata *MD : N->operands())
643     if (MD == N)
644       return true;
645   return false;
646 }
647 
replaceWithPermanentImpl()648 MDNode *MDNode::replaceWithPermanentImpl() {
649   switch (getMetadataID()) {
650   default:
651     // If this type isn't uniquable, replace with a distinct node.
652     return replaceWithDistinctImpl();
653 
654 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
655   case CLASS##Kind:                                                            \
656     break;
657 #include "llvm/IR/Metadata.def"
658   }
659 
660   // Even if this type is uniquable, self-references have to be distinct.
661   if (hasSelfReference(this))
662     return replaceWithDistinctImpl();
663   return replaceWithUniquedImpl();
664 }
665 
replaceWithUniquedImpl()666 MDNode *MDNode::replaceWithUniquedImpl() {
667   // Try to uniquify in place.
668   MDNode *UniquedNode = uniquify();
669 
670   if (UniquedNode == this) {
671     makeUniqued();
672     return this;
673   }
674 
675   // Collision, so RAUW instead.
676   replaceAllUsesWith(UniquedNode);
677   deleteAsSubclass();
678   return UniquedNode;
679 }
680 
replaceWithDistinctImpl()681 MDNode *MDNode::replaceWithDistinctImpl() {
682   makeDistinct();
683   return this;
684 }
685 
recalculateHash()686 void MDTuple::recalculateHash() {
687   setHash(MDTupleInfo::KeyTy::calculateHash(this));
688 }
689 
dropAllReferences()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();
696   }
697 }
698 
handleChangedOperand(void * Ref,Metadata * New)699 void MDNode::handleChangedOperand(void *Ref, Metadata *New) {
700   unsigned Op = static_cast<MDOperand *>(Ref) - op_begin();
701   assert(Op < getNumOperands() && "Expected valid operand");
702 
703   if (!isUniqued()) {
704     // This node is not uniqued.  Just set the operand and be done with it.
705     setOperand(Op, New);
706     return;
707   }
708 
709   // This node is uniqued.
710   eraseFromStore();
711 
712   Metadata *Old = getOperand(Op);
713   setOperand(Op, New);
714 
715   // Drop uniquing for self-reference cycles and deleted constants.
716   if (New == this || (!New && Old && isa<ConstantAsMetadata>(Old))) {
717     if (!isResolved())
718       resolve();
719     storeDistinctInContext();
720     return;
721   }
722 
723   // Re-unique the node.
724   auto *Uniqued = uniquify();
725   if (Uniqued == this) {
726     if (!isResolved())
727       resolveAfterOperandChange(Old, New);
728     return;
729   }
730 
731   // Collision.
732   if (!isResolved()) {
733     // Still unresolved, so RAUW.
734     //
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);
741     deleteAsSubclass();
742     return;
743   }
744 
745   // Store in non-uniqued form if RAUW isn't possible.
746   storeDistinctInContext();
747 }
748 
deleteAsSubclass()749 void MDNode::deleteAsSubclass() {
750   switch (getMetadataID()) {
751   default:
752     llvm_unreachable("Invalid subclass of MDNode");
753 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
754   case CLASS##Kind:                                                            \
755     delete cast<CLASS>(this);                                                  \
756     break;
757 #include "llvm/IR/Metadata.def"
758   }
759 }
760 
761 template <class T, class InfoT>
uniquifyImpl(T * N,DenseSet<T *,InfoT> & Store)762 static T *uniquifyImpl(T *N, DenseSet<T *, InfoT> &Store) {
763   if (T *U = getUniqued(Store, N))
764     return U;
765 
766   Store.insert(N);
767   return N;
768 }
769 
770 template <class NodeTy> struct MDNode::HasCachedHash {
771   using Yes = char[1];
772   using No = char[2];
773   template <class U, U Val> struct SFINAE {};
774 
775   template <class U>
776   static Yes &check(SFINAE<void (U::*)(unsigned), &U::setHash> *);
777   template <class U> static No &check(...);
778 
779   static const bool value = sizeof(check<NodeTy>(nullptr)) == sizeof(Yes);
780 };
781 
uniquify()782 MDNode *MDNode::uniquify() {
783   assert(!hasSelfReference(this) && "Cannot uniquify a self-referencing node");
784 
785   // Try to insert into uniquing store.
786   switch (getMetadataID()) {
787   default:
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);           \
796   }
797 #include "llvm/IR/Metadata.def"
798   }
799 }
800 
eraseFromStore()801 void MDNode::eraseFromStore() {
802   switch (getMetadataID()) {
803   default:
804     llvm_unreachable("Invalid or non-uniquable subclass of MDNode");
805 #define HANDLE_MDNODE_LEAF_UNIQUABLE(CLASS)                                    \
806   case CLASS##Kind:                                                            \
807     getContext().pImpl->CLASS##s.erase(cast<CLASS>(this));                     \
808     break;
809 #include "llvm/IR/Metadata.def"
810   }
811 }
812 
getImpl(LLVMContext & Context,ArrayRef<Metadata * > MDs,StorageType Storage,bool ShouldCreate)813 MDTuple *MDTuple::getImpl(LLVMContext &Context, ArrayRef<Metadata *> MDs,
814                           StorageType Storage, bool ShouldCreate) {
815   unsigned Hash = 0;
816   if (Storage == Uniqued) {
817     MDTupleInfo::KeyTy Key(MDs);
818     if (auto *N = getUniqued(Context.pImpl->MDTuples, Key))
819       return N;
820     if (!ShouldCreate)
821       return nullptr;
822     Hash = Key.getHash();
823   } else {
824     assert(ShouldCreate && "Expected non-uniqued nodes to always be created");
825   }
826 
827   return storeImpl(new (MDs.size()) MDTuple(Context, Storage, Hash, MDs),
828                    Storage, Context.pImpl->MDTuples);
829 }
830 
deleteTemporary(MDNode * N)831 void MDNode::deleteTemporary(MDNode *N) {
832   assert(N->isTemporary() && "Expected temporary node");
833   N->replaceAllUsesWith(nullptr);
834   N->deleteAsSubclass();
835 }
836 
storeDistinctInContext()837 void MDNode::storeDistinctInContext() {
838   assert(!Context.hasReplaceableUses() && "Unexpected replaceable uses");
839   assert(!NumUnresolved && "Unexpected unresolved nodes");
840   Storage = Distinct;
841   assert(isResolved() && "Expected this to be resolved");
842 
843   // Reset the hash.
844   switch (getMetadataID()) {
845   default:
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);                     \
851     break;                                                                     \
852   }
853 #include "llvm/IR/Metadata.def"
854   }
855 
856   getContext().pImpl->DistinctMDNodes.push_back(this);
857 }
858 
replaceOperandWith(unsigned I,Metadata * New)859 void MDNode::replaceOperandWith(unsigned I, Metadata *New) {
860   if (getOperand(I) == New)
861     return;
862 
863   if (!isUniqued()) {
864     setOperand(I, New);
865     return;
866   }
867 
868   handleChangedOperand(mutable_begin() + I, New);
869 }
870 
setOperand(unsigned I,Metadata * New)871 void MDNode::setOperand(unsigned I, Metadata *New) {
872   assert(I < NumOperands);
873   mutable_begin()[I].reset(New, isUniqued() ? this : nullptr);
874 }
875 
876 /// Get a node or a self-reference that looks like it.
877 ///
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.
getOrSelfReference(LLVMContext & Context,ArrayRef<Metadata * > Ops)882 static MDNode *getOrSelfReference(LLVMContext &Context,
883                                   ArrayRef<Metadata *> Ops) {
884   if (!Ops.empty())
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);
890         return N;
891       }
892 
893   return MDNode::get(Context, Ops);
894 }
895 
concatenate(MDNode * A,MDNode * B)896 MDNode *MDNode::concatenate(MDNode *A, MDNode *B) {
897   if (!A)
898     return B;
899   if (!B)
900     return A;
901 
902   SmallSetVector<Metadata *, 4> MDs(A->op_begin(), A->op_end());
903   MDs.insert(B->op_begin(), B->op_end());
904 
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());
908 }
909 
intersect(MDNode * A,MDNode * B)910 MDNode *MDNode::intersect(MDNode *A, MDNode *B) {
911   if (!A || !B)
912     return nullptr;
913 
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); });
917 
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());
921 }
922 
getMostGenericAliasScope(MDNode * A,MDNode * B)923 MDNode *MDNode::getMostGenericAliasScope(MDNode *A, MDNode *B) {
924   if (!A || !B)
925     return nullptr;
926 
927   return concatenate(A, B);
928 }
929 
getMostGenericFPMath(MDNode * A,MDNode * B)930 MDNode *MDNode::getMostGenericFPMath(MDNode *A, MDNode *B) {
931   if (!A || !B)
932     return nullptr;
933 
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)
937     return A;
938   return B;
939 }
940 
isContiguous(const ConstantRange & A,const ConstantRange & B)941 static bool isContiguous(const ConstantRange &A, const ConstantRange &B) {
942   return A.getUpper() == B.getLower() || A.getLower() == B.getUpper();
943 }
944 
canBeMerged(const ConstantRange & A,const ConstantRange & B)945 static bool canBeMerged(const ConstantRange &A, const ConstantRange &B) {
946   return !A.intersectWith(B).isEmptySet() || isContiguous(A, B);
947 }
948 
tryMergeRange(SmallVectorImpl<ConstantInt * > & EndPoints,ConstantInt * Low,ConstantInt * High)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()));
963     return true;
964   }
965   return false;
966 }
967 
addRange(SmallVectorImpl<ConstantInt * > & EndPoints,ConstantInt * Low,ConstantInt * High)968 static void addRange(SmallVectorImpl<ConstantInt *> &EndPoints,
969                      ConstantInt *Low, ConstantInt *High) {
970   if (!EndPoints.empty())
971     if (tryMergeRange(EndPoints, Low, High))
972       return;
973 
974   EndPoints.push_back(Low);
975   EndPoints.push_back(High);
976 }
977 
getMostGenericRange(MDNode * A,MDNode * B)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.
982 
983   if (!A || !B)
984     return nullptr;
985 
986   if (A == B)
987     return A;
988 
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;
992   int AI = 0;
993   int BI = 0;
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));
999 
1000     if (ALow->getValue().slt(BLow->getValue())) {
1001       addRange(EndPoints, ALow,
1002                mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
1003       ++AI;
1004     } else {
1005       addRange(EndPoints, BLow,
1006                mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
1007       ++BI;
1008     }
1009   }
1010   while (AI < AN) {
1011     addRange(EndPoints, mdconst::extract<ConstantInt>(A->getOperand(2 * AI)),
1012              mdconst::extract<ConstantInt>(A->getOperand(2 * AI + 1)));
1013     ++AI;
1014   }
1015   while (BI < BN) {
1016     addRange(EndPoints, mdconst::extract<ConstantInt>(B->getOperand(2 * BI)),
1017              mdconst::extract<ConstantInt>(B->getOperand(2 * BI + 1)));
1018     ++BI;
1019   }
1020 
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();
1024   if (Size > 4) {
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];
1030       }
1031       EndPoints.resize(Size - 2);
1032     }
1033   }
1034 
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())
1040       return nullptr;
1041   }
1042 
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);
1048 }
1049 
getMostGenericAlignmentOrDereferenceable(MDNode * A,MDNode * B)1050 MDNode *MDNode::getMostGenericAlignmentOrDereferenceable(MDNode *A, MDNode *B) {
1051   if (!A || !B)
1052     return nullptr;
1053 
1054   ConstantInt *AVal = mdconst::extract<ConstantInt>(A->getOperand(0));
1055   ConstantInt *BVal = mdconst::extract<ConstantInt>(B->getOperand(0));
1056   if (AVal->getZExtValue() < BVal->getZExtValue())
1057     return A;
1058   return B;
1059 }
1060 
1061 //===----------------------------------------------------------------------===//
1062 // NamedMDNode implementation.
1063 //
1064 
getNMDOps(void * Operands)1065 static SmallVector<TrackingMDRef, 4> &getNMDOps(void *Operands) {
1066   return *(SmallVector<TrackingMDRef, 4> *)Operands;
1067 }
1068 
NamedMDNode(const Twine & N)1069 NamedMDNode::NamedMDNode(const Twine &N)
1070     : Name(N.str()), Operands(new SmallVector<TrackingMDRef, 4>()) {}
1071 
~NamedMDNode()1072 NamedMDNode::~NamedMDNode() {
1073   dropAllReferences();
1074   delete &getNMDOps(Operands);
1075 }
1076 
getNumOperands() const1077 unsigned NamedMDNode::getNumOperands() const {
1078   return (unsigned)getNMDOps(Operands).size();
1079 }
1080 
getOperand(unsigned i) const1081 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);
1085 }
1086 
addOperand(MDNode * M)1087 void NamedMDNode::addOperand(MDNode *M) { getNMDOps(Operands).emplace_back(M); }
1088 
setOperand(unsigned I,MDNode * New)1089 void NamedMDNode::setOperand(unsigned I, MDNode *New) {
1090   assert(I < getNumOperands() && "Invalid operand number");
1091   getNMDOps(Operands)[I].reset(New);
1092 }
1093 
eraseFromParent()1094 void NamedMDNode::eraseFromParent() { getParent()->eraseNamedMetadata(this); }
1095 
clearOperands()1096 void NamedMDNode::clearOperands() { getNMDOps(Operands).clear(); }
1097 
getName() const1098 StringRef NamedMDNode::getName() const { return StringRef(Name); }
1099 
1100 //===----------------------------------------------------------------------===//
1101 // Instruction Metadata method implementations.
1102 //
set(unsigned ID,MDNode & MD)1103 void MDAttachmentMap::set(unsigned ID, MDNode &MD) {
1104   for (auto &I : Attachments)
1105     if (I.first == ID) {
1106       I.second.reset(&MD);
1107       return;
1108     }
1109   Attachments.emplace_back(std::piecewise_construct, std::make_tuple(ID),
1110                            std::make_tuple(&MD));
1111 }
1112 
erase(unsigned ID)1113 bool MDAttachmentMap::erase(unsigned ID) {
1114   if (empty())
1115     return false;
1116 
1117   // Common case is one/last value.
1118   if (Attachments.back().first == ID) {
1119     Attachments.pop_back();
1120     return true;
1121   }
1122 
1123   for (auto I = Attachments.begin(), E = std::prev(Attachments.end()); I != E;
1124        ++I)
1125     if (I->first == ID) {
1126       *I = std::move(Attachments.back());
1127       Attachments.pop_back();
1128       return true;
1129     }
1130 
1131   return false;
1132 }
1133 
lookup(unsigned ID) const1134 MDNode *MDAttachmentMap::lookup(unsigned ID) const {
1135   for (const auto &I : Attachments)
1136     if (I.first == ID)
1137       return I.second;
1138   return nullptr;
1139 }
1140 
getAll(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1141 void MDAttachmentMap::getAll(
1142     SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1143   Result.append(Attachments.begin(), Attachments.end());
1144 
1145   // Sort the resulting array so it is stable.
1146   if (Result.size() > 1)
1147     array_pod_sort(Result.begin(), Result.end());
1148 }
1149 
insert(unsigned ID,MDNode & MD)1150 void MDGlobalAttachmentMap::insert(unsigned ID, MDNode &MD) {
1151   Attachments.push_back({ID, TrackingMDNodeRef(&MD)});
1152 }
1153 
lookup(unsigned ID) const1154 MDNode *MDGlobalAttachmentMap::lookup(unsigned ID) const {
1155   for (const auto &A : Attachments)
1156     if (A.MDKind == ID)
1157       return A.Node;
1158   return nullptr;
1159 }
1160 
get(unsigned ID,SmallVectorImpl<MDNode * > & Result) const1161 void MDGlobalAttachmentMap::get(unsigned ID,
1162                                 SmallVectorImpl<MDNode *> &Result) const {
1163   for (const auto &A : Attachments)
1164     if (A.MDKind == ID)
1165       Result.push_back(A.Node);
1166 }
1167 
erase(unsigned ID)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());
1173   return Changed;
1174 }
1175 
getAll(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1176 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);
1180 
1181   // Sort the resulting array so it is stable with respect to metadata IDs. We
1182   // need to preserve the original insertion order though.
1183   std::stable_sort(
1184       Result.begin(), Result.end(),
1185       [](const std::pair<unsigned, MDNode *> &A,
1186          const std::pair<unsigned, MDNode *> &B) { return A.first < B.first; });
1187 }
1188 
setMetadata(StringRef Kind,MDNode * Node)1189 void Instruction::setMetadata(StringRef Kind, MDNode *Node) {
1190   if (!Node && !hasMetadata())
1191     return;
1192   setMetadata(getContext().getMDKindID(Kind), Node);
1193 }
1194 
getMetadataImpl(StringRef Kind) const1195 MDNode *Instruction::getMetadataImpl(StringRef Kind) const {
1196   return getMetadataImpl(getContext().getMDKindID(Kind));
1197 }
1198 
dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs)1199 void Instruction::dropUnknownNonDebugMetadata(ArrayRef<unsigned> KnownIDs) {
1200   if (!hasMetadataHashEntry())
1201     return; // Nothing to remove!
1202 
1203   auto &InstructionMetadata = getContext().pImpl->InstructionMetadata;
1204 
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);
1211     return;
1212   }
1213 
1214   auto &Info = InstructionMetadata[this];
1215   Info.remove_if([&KnownSet](const std::pair<unsigned, TrackingMDNodeRef> &I) {
1216     return !KnownSet.count(I.first);
1217   });
1218 
1219   if (Info.empty()) {
1220     // Drop our entry at the store.
1221     InstructionMetadata.erase(this);
1222     setHasMetadataHashEntry(false);
1223   }
1224 }
1225 
setMetadata(unsigned KindID,MDNode * Node)1226 void Instruction::setMetadata(unsigned KindID, MDNode *Node) {
1227   if (!Node && !hasMetadata())
1228     return;
1229 
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);
1233     return;
1234   }
1235 
1236   // Handle the case when we're adding/updating metadata on an instruction.
1237   if (Node) {
1238     auto &Info = getContext().pImpl->InstructionMetadata[this];
1239     assert(!Info.empty() == hasMetadataHashEntry() &&
1240            "HasMetadata bit is wonked");
1241     if (Info.empty())
1242       setHasMetadataHashEntry(true);
1243     Info.set(KindID, *Node);
1244     return;
1245   }
1246 
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];
1254 
1255   // Handle removal of an existing value.
1256   Info.erase(KindID);
1257 
1258   if (!Info.empty())
1259     return;
1260 
1261   getContext().pImpl->InstructionMetadata.erase(this);
1262   setHasMetadataHashEntry(false);
1263 }
1264 
setAAMetadata(const AAMDNodes & N)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);
1269 }
1270 
getMetadataImpl(unsigned KindID) const1271 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();
1275 
1276   if (!hasMetadataHashEntry())
1277     return nullptr;
1278   auto &Info = getContext().pImpl->InstructionMetadata[this];
1279   assert(!Info.empty() && "bit out of sync with hash table");
1280 
1281   return Info.lookup(KindID);
1282 }
1283 
getAllMetadataImpl(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1284 void Instruction::getAllMetadataImpl(
1285     SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1286   Result.clear();
1287 
1288   // Handle 'dbg' as a special case since it is not stored in the hash table.
1289   if (DbgLoc) {
1290     Result.push_back(
1291         std::make_pair((unsigned)LLVMContext::MD_dbg, DbgLoc.getAsMDNode()));
1292     if (!hasMetadataHashEntry())
1293       return;
1294   }
1295 
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);
1302 }
1303 
getAllMetadataOtherThanDebugLocImpl(SmallVectorImpl<std::pair<unsigned,MDNode * >> & Result) const1304 void Instruction::getAllMetadataOtherThanDebugLocImpl(
1305     SmallVectorImpl<std::pair<unsigned, MDNode *>> &Result) const {
1306   Result.clear();
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);
1313 }
1314 
extractProfMetadata(uint64_t & TrueVal,uint64_t & FalseVal) const1315 bool Instruction::extractProfMetadata(uint64_t &TrueVal,
1316                                       uint64_t &FalseVal) const {
1317   assert(
1318       (getOpcode() == Instruction::Br || getOpcode() == Instruction::Select) &&
1319       "Looking for branch weights on something besides branch or select");
1320 
1321   auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1322   if (!ProfileData || ProfileData->getNumOperands() != 3)
1323     return false;
1324 
1325   auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1326   if (!ProfDataName || !ProfDataName->getString().equals("branch_weights"))
1327     return false;
1328 
1329   auto *CITrue = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(1));
1330   auto *CIFalse = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2));
1331   if (!CITrue || !CIFalse)
1332     return false;
1333 
1334   TrueVal = CITrue->getValue().getZExtValue();
1335   FalseVal = CIFalse->getValue().getZExtValue();
1336 
1337   return true;
1338 }
1339 
extractProfTotalWeight(uint64_t & TotalVal) const1340 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");
1347 
1348   TotalVal = 0;
1349   auto *ProfileData = getMetadata(LLVMContext::MD_prof);
1350   if (!ProfileData)
1351     return false;
1352 
1353   auto *ProfDataName = dyn_cast<MDString>(ProfileData->getOperand(0));
1354   if (!ProfDataName)
1355     return false;
1356 
1357   if (ProfDataName->getString().equals("branch_weights")) {
1358     TotalVal = 0;
1359     for (unsigned i = 1; i < ProfileData->getNumOperands(); i++) {
1360       auto *V = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(i));
1361       if (!V)
1362         return false;
1363       TotalVal += V->getValue().getZExtValue();
1364     }
1365     return true;
1366   } else if (ProfDataName->getString().equals("VP") &&
1367              ProfileData->getNumOperands() > 3) {
1368     TotalVal = mdconst::dyn_extract<ConstantInt>(ProfileData->getOperand(2))
1369                    ->getValue()
1370                    .getZExtValue();
1371     return true;
1372   }
1373   return false;
1374 }
1375 
clearMetadataHashEntries()1376 void Instruction::clearMetadataHashEntries() {
1377   assert(hasMetadataHashEntry() && "Caller should check");
1378   getContext().pImpl->InstructionMetadata.erase(this);
1379   setHasMetadataHashEntry(false);
1380 }
1381 
getMetadata(unsigned KindID,SmallVectorImpl<MDNode * > & MDs) const1382 void GlobalObject::getMetadata(unsigned KindID,
1383                                SmallVectorImpl<MDNode *> &MDs) const {
1384   if (hasMetadata())
1385     getContext().pImpl->GlobalObjectMetadata[this].get(KindID, MDs);
1386 }
1387 
getMetadata(StringRef Kind,SmallVectorImpl<MDNode * > & MDs) const1388 void GlobalObject::getMetadata(StringRef Kind,
1389                                SmallVectorImpl<MDNode *> &MDs) const {
1390   if (hasMetadata())
1391     getMetadata(getContext().getMDKindID(Kind), MDs);
1392 }
1393 
addMetadata(unsigned KindID,MDNode & MD)1394 void GlobalObject::addMetadata(unsigned KindID, MDNode &MD) {
1395   if (!hasMetadata())
1396     setHasMetadataHashEntry(true);
1397 
1398   getContext().pImpl->GlobalObjectMetadata[this].insert(KindID, MD);
1399 }
1400 
addMetadata(StringRef Kind,MDNode & MD)1401 void GlobalObject::addMetadata(StringRef Kind, MDNode &MD) {
1402   addMetadata(getContext().getMDKindID(Kind), MD);
1403 }
1404 
eraseMetadata(unsigned KindID)1405 bool GlobalObject::eraseMetadata(unsigned KindID) {
1406   // Nothing to unset.
1407   if (!hasMetadata())
1408     return false;
1409 
1410   auto &Store = getContext().pImpl->GlobalObjectMetadata[this];
1411   bool Changed = Store.erase(KindID);
1412   if (Store.empty())
1413     clearMetadata();
1414   return Changed;
1415 }
1416 
getAllMetadata(SmallVectorImpl<std::pair<unsigned,MDNode * >> & MDs) const1417 void GlobalObject::getAllMetadata(
1418     SmallVectorImpl<std::pair<unsigned, MDNode *>> &MDs) const {
1419   MDs.clear();
1420 
1421   if (!hasMetadata())
1422     return;
1423 
1424   getContext().pImpl->GlobalObjectMetadata[this].getAll(MDs);
1425 }
1426 
clearMetadata()1427 void GlobalObject::clearMetadata() {
1428   if (!hasMetadata())
1429     return;
1430   getContext().pImpl->GlobalObjectMetadata.erase(this);
1431   setHasMetadataHashEntry(false);
1432 }
1433 
setMetadata(unsigned KindID,MDNode * N)1434 void GlobalObject::setMetadata(unsigned KindID, MDNode *N) {
1435   eraseMetadata(KindID);
1436   if (N)
1437     addMetadata(KindID, *N);
1438 }
1439 
setMetadata(StringRef Kind,MDNode * N)1440 void GlobalObject::setMetadata(StringRef Kind, MDNode *N) {
1441   setMetadata(getContext().getMDKindID(Kind), N);
1442 }
1443 
getMetadata(unsigned KindID) const1444 MDNode *GlobalObject::getMetadata(unsigned KindID) const {
1445   if (hasMetadata())
1446     return getContext().pImpl->GlobalObjectMetadata[this].lookup(KindID);
1447   return nullptr;
1448 }
1449 
getMetadata(StringRef Kind) const1450 MDNode *GlobalObject::getMetadata(StringRef Kind) const {
1451   return getMetadata(getContext().getMDKindID(Kind));
1452 }
1453 
copyMetadata(const GlobalObject * Other,unsigned Offset)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}));
1467       continue;
1468     }
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;
1476       if (!GV) {
1477         auto *GVE = cast<DIGlobalVariableExpression>(Attachment);
1478         GV = GVE->getVariable();
1479         E = GVE->getExpression();
1480       }
1481       ArrayRef<uint64_t> OrigElements;
1482       if (E)
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);
1490     }
1491     addMetadata(MD.first, *Attachment);
1492   }
1493 }
1494 
addTypeMetadata(unsigned Offset,Metadata * TypeID)1495 void GlobalObject::addTypeMetadata(unsigned Offset, Metadata *TypeID) {
1496   addMetadata(
1497       LLVMContext::MD_type,
1498       *MDTuple::get(getContext(),
1499                     {ConstantAsMetadata::get(ConstantInt::get(
1500                          Type::getInt64Ty(getContext()), Offset)),
1501                      TypeID}));
1502 }
1503 
setSubprogram(DISubprogram * SP)1504 void Function::setSubprogram(DISubprogram *SP) {
1505   setMetadata(LLVMContext::MD_dbg, SP);
1506 }
1507 
getSubprogram() const1508 DISubprogram *Function::getSubprogram() const {
1509   return cast_or_null<DISubprogram>(getMetadata(LLVMContext::MD_dbg));
1510 }
1511 
isDebugInfoForProfiling() const1512 bool Function::isDebugInfoForProfiling() const {
1513   if (DISubprogram *SP = getSubprogram()) {
1514     if (DICompileUnit *CU = SP->getUnit()) {
1515       return CU->getDebugInfoForProfiling();
1516     }
1517   }
1518   return false;
1519 }
1520 
addDebugInfo(DIGlobalVariableExpression * GV)1521 void GlobalVariable::addDebugInfo(DIGlobalVariableExpression *GV) {
1522   addMetadata(LLVMContext::MD_dbg, *GV);
1523 }
1524 
getDebugInfo(SmallVectorImpl<DIGlobalVariableExpression * > & GVs) const1525 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));
1531 }
1532