diff options
Diffstat (limited to 'lib/VMCore/Value.cpp')
-rw-r--r-- | lib/VMCore/Value.cpp | 337 |
1 files changed, 181 insertions, 156 deletions
diff --git a/lib/VMCore/Value.cpp b/lib/VMCore/Value.cpp index c952b7888cdd..ba72af635cdc 100644 --- a/lib/VMCore/Value.cpp +++ b/lib/VMCore/Value.cpp @@ -11,17 +11,23 @@ // //===----------------------------------------------------------------------===// +#include "LLVMContextImpl.h" #include "llvm/Constant.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" #include "llvm/InstrTypes.h" #include "llvm/Instructions.h" +#include "llvm/Operator.h" #include "llvm/Module.h" +#include "llvm/Metadata.h" #include "llvm/ValueSymbolTable.h" +#include "llvm/ADT/SmallString.h" #include "llvm/Support/Debug.h" +#include "llvm/Support/ErrorHandling.h" #include "llvm/Support/LeakDetector.h" #include "llvm/Support/ManagedStatic.h" #include "llvm/Support/ValueHandle.h" +#include "llvm/Support/raw_ostream.h" #include "llvm/System/RWMutex.h" #include "llvm/System/Threading.h" #include "llvm/ADT/DenseMap.h" @@ -38,23 +44,31 @@ static inline const Type *checkType(const Type *Ty) { } Value::Value(const Type *ty, unsigned scid) - : SubclassID(scid), HasValueHandle(0), SubclassData(0), VTy(checkType(ty)), + : SubclassID(scid), HasValueHandle(0), HasMetadata(0), + SubclassOptionalData(0), SubclassData(0), VTy(checkType(ty)), UseList(0), Name(0) { if (isa<CallInst>(this) || isa<InvokeInst>(this)) - assert((VTy->isFirstClassType() || VTy == Type::VoidTy || + assert((VTy->isFirstClassType() || + VTy == Type::getVoidTy(ty->getContext()) || isa<OpaqueType>(ty) || VTy->getTypeID() == Type::StructTyID) && "invalid CallInst type!"); else if (!isa<Constant>(this) && !isa<BasicBlock>(this)) - assert((VTy->isFirstClassType() || VTy == Type::VoidTy || + assert((VTy->isFirstClassType() || + VTy == Type::getVoidTy(ty->getContext()) || isa<OpaqueType>(ty)) && "Cannot create non-first-class values except for constants!"); } Value::~Value() { + if (HasMetadata) { + LLVMContext &Context = getContext(); + Context.pImpl->TheMetadata.ValueIsDeleted(this); + } + // Notify all ValueHandles (if present) that this value is going away. if (HasValueHandle) ValueHandleBase::ValueIsDeleted(this); - + #ifndef NDEBUG // Only in -g mode... // Check to make sure that there are no uses of this value that are still // around when the value is destroyed. If there are, then we have a dangling @@ -63,9 +77,9 @@ Value::~Value() { // a <badref> // if (!use_empty()) { - cerr << "While deleting: " << *VTy << " %" << getNameStr() << "\n"; + errs() << "While deleting: " << *VTy << " %" << getNameStr() << "\n"; for (use_iterator I = use_begin(), E = use_end(); I != E; ++I) - cerr << "Use still stuck around after Def is destroyed:" + errs() << "Use still stuck around after Def is destroyed:" << **I << "\n"; } #endif @@ -75,7 +89,7 @@ Value::~Value() { // at this point. if (Name) Name->Destroy(); - + // There should be no uses of this object anymore, remove it. LeakDetector::removeGarbageObject(this); } @@ -128,61 +142,57 @@ static bool getSymTab(Value *V, ValueSymbolTable *&ST) { if (Function *PP = P->getParent()) ST = &PP->getValueSymbolTable(); } else if (BasicBlock *BB = dyn_cast<BasicBlock>(V)) { - if (Function *P = BB->getParent()) + if (Function *P = BB->getParent()) ST = &P->getValueSymbolTable(); } else if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) { - if (Module *P = GV->getParent()) + if (Module *P = GV->getParent()) ST = &P->getValueSymbolTable(); } else if (Argument *A = dyn_cast<Argument>(V)) { - if (Function *P = A->getParent()) + if (Function *P = A->getParent()) + ST = &P->getValueSymbolTable(); + } else if (NamedMDNode *N = dyn_cast<NamedMDNode>(V)) { + if (Module *P = N->getParent()) { ST = &P->getValueSymbolTable(); - } else { + } + } else if (isa<MDString>(V)) + return true; + else { assert(isa<Constant>(V) && "Unknown value type!"); return true; // no name is setable for this. } return false; } -/// getNameStart - Return a pointer to a null terminated string for this name. -/// Note that names can have null characters within the string as well as at -/// their end. This always returns a non-null pointer. -const char *Value::getNameStart() const { - if (Name == 0) return ""; - return Name->getKeyData(); +StringRef Value::getName() const { + // Make sure the empty string is still a C string. For historical reasons, + // some clients want to call .data() on the result and expect it to be null + // terminated. + if (!Name) return StringRef("", 0); + return Name->getKey(); } -/// getNameLen - Return the length of the string, correctly handling nul -/// characters embedded into them. -unsigned Value::getNameLen() const { - return Name ? Name->getKeyLength() : 0; +std::string Value::getNameStr() const { + return getName().str(); } -/// isName - Return true if this value has the name specified by the provided -/// nul terminated string. -bool Value::isName(const char *N) const { - unsigned InLen = strlen(N); - return InLen == getNameLen() && memcmp(getNameStart(), N, InLen) == 0; -} +void Value::setName(const Twine &NewName) { + // Fast path for common IRBuilder case of setName("") when there is no name. + if (NewName.isTriviallyEmpty() && !hasName()) + return; + SmallString<256> NameData; + NewName.toVector(NameData); -std::string Value::getNameStr() const { - if (Name == 0) return ""; - return std::string(Name->getKeyData(), - Name->getKeyData()+Name->getKeyLength()); -} + const char *NameStr = NameData.data(); + unsigned NameLen = NameData.size(); -void Value::setName(const std::string &name) { - setName(&name[0], name.size()); -} + // Name isn't changing? + if (getName() == StringRef(NameStr, NameLen)) + return; -void Value::setName(const char *Name) { - setName(Name, Name ? strlen(Name) : 0); -} + assert(getType() != Type::getVoidTy(getContext()) && + "Cannot assign a name to void values!"); -void Value::setName(const char *NameStr, unsigned NameLen) { - if (NameLen == 0 && !hasName()) return; - assert(getType() != Type::VoidTy && "Cannot assign a name to void values!"); - // Get the symbol table to update for this object. ValueSymbolTable *ST; if (getSymTab(this, ST)) @@ -195,32 +205,22 @@ void Value::setName(const char *NameStr, unsigned NameLen) { Name = 0; return; } - - if (Name) { - // Name isn't changing? - if (NameLen == Name->getKeyLength() && - !memcmp(Name->getKeyData(), NameStr, NameLen)) - return; + + if (Name) Name->Destroy(); - } - + // NOTE: Could optimize for the case the name is shrinking to not deallocate // then reallocated. - + // Create the new name. Name = ValueName::Create(NameStr, NameStr+NameLen); Name->setValue(this); return; } - + // NOTE: Could optimize for the case the name is shrinking to not deallocate // then reallocated. if (hasName()) { - // Name isn't changing? - if (NameLen == Name->getKeyLength() && - !memcmp(Name->getKeyData(), NameStr, NameLen)) - return; - // Remove old name. ST->removeValueName(Name); Name->Destroy(); @@ -231,12 +231,12 @@ void Value::setName(const char *NameStr, unsigned NameLen) { } // Name is changing to something new. - Name = ST->createValueName(NameStr, NameLen, this); + Name = ST->createValueName(StringRef(NameStr, NameLen), this); } /// takeName - transfer the name from V to this value, setting V's name to -/// empty. It is an error to call V->takeName(V). +/// empty. It is an error to call V->takeName(V). void Value::takeName(Value *V) { ValueSymbolTable *ST = 0; // If this value has a name, drop it. @@ -245,36 +245,36 @@ void Value::takeName(Value *V) { if (getSymTab(this, ST)) { // We can't set a name on this value, but we need to clear V's name if // it has one. - if (V->hasName()) V->setName(0, 0); + if (V->hasName()) V->setName(""); return; // Cannot set a name on this value (e.g. constant). } - + // Remove old name. if (ST) ST->removeValueName(Name); Name->Destroy(); Name = 0; - } - + } + // Now we know that this has no name. - + // If V has no name either, we're done. if (!V->hasName()) return; - + // Get this's symtab if we didn't before. if (!ST) { if (getSymTab(this, ST)) { // Clear V's name. - V->setName(0, 0); + V->setName(""); return; // Cannot set a name on this value (e.g. constant). } } - + // Get V's ST, this should always succed, because V has a name. ValueSymbolTable *VST; bool Failure = getSymTab(V, VST); assert(!Failure && "V has a name, so it should have a ST!"); Failure=Failure; - + // If these values are both in the same symtab, we can do this very fast. // This works even if both values have no symtab yet. if (ST == VST) { @@ -284,16 +284,16 @@ void Value::takeName(Value *V) { Name->setValue(this); return; } - + // Otherwise, things are slightly more complex. Remove V's name from VST and // then reinsert it into ST. - + if (VST) VST->removeValueName(V->Name); Name = V->Name; V->Name = 0; Name->setValue(this); - + if (ST) ST->reinsertValue(this); } @@ -309,7 +309,11 @@ void Value::uncheckedReplaceAllUsesWith(Value *New) { // Notify all ValueHandles (if present) that this value is going away. if (HasValueHandle) ValueHandleBase::ValueIsRAUWd(this, New); - + if (HasMetadata) { + LLVMContext &Context = getContext(); + Context.pImpl->TheMetadata.ValueIsRAUWd(this, New); + } + while (!use_empty()) { Use &U = *UseList; // Must handle Constants specially, we cannot call replaceUsesOfWith on a @@ -320,7 +324,7 @@ void Value::uncheckedReplaceAllUsesWith(Value *New) { continue; } } - + U.set(New); } } @@ -339,23 +343,16 @@ Value *Value::stripPointerCasts() { return this; Value *V = this; do { - if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) { - if (CE->getOpcode() == Instruction::GetElementPtr) { - for (unsigned i = 1, e = CE->getNumOperands(); i != e; ++i) - if (!CE->getOperand(i)->isNullValue()) - return V; - V = CE->getOperand(0); - } else if (CE->getOpcode() == Instruction::BitCast) { - V = CE->getOperand(0); - } else { - return V; - } - } else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(V)) { + if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) { if (!GEP->hasAllZeroIndices()) return V; - V = GEP->getOperand(0); - } else if (BitCastInst *CI = dyn_cast<BitCastInst>(V)) { - V = CI->getOperand(0); + V = GEP->getPointerOperand(); + } else if (Operator::getOpcode(V) == Instruction::BitCast) { + V = cast<Operator>(V)->getOperand(0); + } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) { + if (GA->mayBeOverridden()) + return V; + V = GA->getAliasee(); } else { return V; } @@ -369,15 +366,14 @@ Value *Value::getUnderlyingObject() { Value *V = this; unsigned MaxLookup = 6; do { - if (Instruction *I = dyn_cast<Instruction>(V)) { - if (!isa<BitCastInst>(I) && !isa<GetElementPtrInst>(I)) - return V; - V = I->getOperand(0); - } else if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) { - if (CE->getOpcode() != Instruction::BitCast && - CE->getOpcode() != Instruction::GetElementPtr) + if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) { + V = GEP->getPointerOperand(); + } else if (Operator::getOpcode(V) == Instruction::BitCast) { + V = cast<Operator>(V)->getOperand(0); + } else if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) { + if (GA->mayBeOverridden()) return V; - V = CE->getOperand(0); + V = GA->getAliasee(); } else { return V; } @@ -390,7 +386,7 @@ Value *Value::getUnderlyingObject() { /// return the value in the PHI node corresponding to PredBB. If not, return /// ourself. This is useful if you want to know the value something has in a /// predecessor block. -Value *Value::DoPHITranslation(const BasicBlock *CurBB, +Value *Value::DoPHITranslation(const BasicBlock *CurBB, const BasicBlock *PredBB) { PHINode *PN = dyn_cast<PHINode>(this); if (PN && PN->getParent() == CurBB) @@ -398,22 +394,17 @@ Value *Value::DoPHITranslation(const BasicBlock *CurBB, return this; } +LLVMContext &Value::getContext() const { return VTy->getContext(); } + //===----------------------------------------------------------------------===// // ValueHandleBase Class //===----------------------------------------------------------------------===// -/// ValueHandles - This map keeps track of all of the value handles that are -/// watching a Value*. The Value::HasValueHandle bit is used to know whether or -/// not a value has an entry in this map. -typedef DenseMap<Value*, ValueHandleBase*> ValueHandlesTy; -static ManagedStatic<ValueHandlesTy> ValueHandles; -static ManagedStatic<sys::SmartRWMutex<true> > ValueHandlesLock; - /// AddToExistingUseList - Add this ValueHandle to the use list for VP, where /// List is known to point into the existing use list. void ValueHandleBase::AddToExistingUseList(ValueHandleBase **List) { assert(List && "Handle list is null?"); - + // Splice ourselves into the list. Next = *List; *List = this; @@ -424,43 +415,54 @@ void ValueHandleBase::AddToExistingUseList(ValueHandleBase **List) { } } +void ValueHandleBase::AddToExistingUseListAfter(ValueHandleBase *List) { + assert(List && "Must insert after existing node"); + + Next = List->Next; + setPrevPtr(&List->Next); + List->Next = this; + if (Next) + Next->setPrevPtr(&Next); +} + /// AddToUseList - Add this ValueHandle to the use list for VP. void ValueHandleBase::AddToUseList() { assert(VP && "Null pointer doesn't have a use list!"); + + LLVMContextImpl *pImpl = VP->getContext().pImpl; + if (VP->HasValueHandle) { // If this value already has a ValueHandle, then it must be in the // ValueHandles map already. - sys::SmartScopedReader<true> Reader(&*ValueHandlesLock); - ValueHandleBase *&Entry = (*ValueHandles)[VP]; + ValueHandleBase *&Entry = pImpl->ValueHandles[VP]; assert(Entry != 0 && "Value doesn't have any handles?"); AddToExistingUseList(&Entry); return; } - + // Ok, it doesn't have any handles yet, so we must insert it into the // DenseMap. However, doing this insertion could cause the DenseMap to // reallocate itself, which would invalidate all of the PrevP pointers that // point into the old table. Handle this by checking for reallocation and // updating the stale pointers only if needed. - sys::SmartScopedWriter<true> Writer(&*ValueHandlesLock); - ValueHandlesTy &Handles = *ValueHandles; + DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles; const void *OldBucketPtr = Handles.getPointerIntoBucketsArray(); - + ValueHandleBase *&Entry = Handles[VP]; assert(Entry == 0 && "Value really did already have handles?"); AddToExistingUseList(&Entry); VP->HasValueHandle = true; - + // If reallocation didn't happen or if this was the first insertion, don't // walk the table. - if (Handles.isPointerIntoBucketsArray(OldBucketPtr) || + if (Handles.isPointerIntoBucketsArray(OldBucketPtr) || Handles.size() == 1) { return; } - + // Okay, reallocation did happen. Fix the Prev Pointers. - for (ValueHandlesTy::iterator I = Handles.begin(), E = Handles.end(); - I != E; ++I) { + for (DenseMap<Value*, ValueHandleBase*>::iterator I = Handles.begin(), + E = Handles.end(); I != E; ++I) { assert(I->second && I->first == I->second->VP && "List invariant broken!"); I->second->setPrevPtr(&I->second); } @@ -473,19 +475,19 @@ void ValueHandleBase::RemoveFromUseList() { // Unlink this from its use list. ValueHandleBase **PrevPtr = getPrevPtr(); assert(*PrevPtr == this && "List invariant broken"); - + *PrevPtr = Next; if (Next) { assert(Next->getPrevPtr() == &Next && "List invariant broken"); Next->setPrevPtr(PrevPtr); return; } - + // If the Next pointer was null, then it is possible that this was the last // ValueHandle watching VP. If so, delete its entry from the ValueHandles // map. - sys::SmartScopedWriter<true> Writer(&*ValueHandlesLock); - ValueHandlesTy &Handles = *ValueHandles; + LLVMContextImpl *pImpl = VP->getContext().pImpl; + DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles; if (Handles.isPointerIntoBucketsArray(PrevPtr)) { Handles.erase(VP); VP->HasValueHandle = false; @@ -498,67 +500,91 @@ void ValueHandleBase::ValueIsDeleted(Value *V) { // Get the linked list base, which is guaranteed to exist since the // HasValueHandle flag is set. - ValueHandlesLock->reader_acquire(); - ValueHandleBase *Entry = (*ValueHandles)[V]; - ValueHandlesLock->reader_release(); + LLVMContextImpl *pImpl = V->getContext().pImpl; + ValueHandleBase *Entry = pImpl->ValueHandles[V]; assert(Entry && "Value bit set but no entries exist"); - - while (Entry) { - // Advance pointer to avoid invalidation. - ValueHandleBase *ThisNode = Entry; - Entry = Entry->Next; - - switch (ThisNode->getKind()) { + + // We use a local ValueHandleBase as an iterator so that + // ValueHandles can add and remove themselves from the list without + // breaking our iteration. This is not really an AssertingVH; we + // just have to give ValueHandleBase some kind. + for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) { + Iterator.RemoveFromUseList(); + Iterator.AddToExistingUseListAfter(Entry); + assert(Entry->Next == &Iterator && "Loop invariant broken."); + + switch (Entry->getKind()) { case Assert: -#ifndef NDEBUG // Only in -g mode... - cerr << "While deleting: " << *V->getType() << " %" << V->getNameStr() - << "\n"; -#endif - cerr << "An asserting value handle still pointed to this value!\n"; - abort(); + break; + case Tracking: + // Mark that this value has been deleted by setting it to an invalid Value + // pointer. + Entry->operator=(DenseMapInfo<Value *>::getTombstoneKey()); + break; case Weak: // Weak just goes to null, which will unlink it from the list. - ThisNode->operator=(0); + Entry->operator=(0); break; case Callback: // Forward to the subclass's implementation. - static_cast<CallbackVH*>(ThisNode)->deleted(); + static_cast<CallbackVH*>(Entry)->deleted(); break; } } - - // All callbacks and weak references should be dropped by now. - assert(!V->HasValueHandle && "All references to V were not removed?"); + + // All callbacks, weak references, and assertingVHs should be dropped by now. + if (V->HasValueHandle) { +#ifndef NDEBUG // Only in +Asserts mode... + errs() << "While deleting: " << *V->getType() << " %" << V->getNameStr() + << "\n"; + if (pImpl->ValueHandles[V]->getKind() == Assert) + llvm_unreachable("An asserting value handle still pointed to this" + " value!"); + +#endif + llvm_unreachable("All references to V were not removed?"); + } } void ValueHandleBase::ValueIsRAUWd(Value *Old, Value *New) { assert(Old->HasValueHandle &&"Should only be called if ValueHandles present"); assert(Old != New && "Changing value into itself!"); - + // Get the linked list base, which is guaranteed to exist since the // HasValueHandle flag is set. - ValueHandlesLock->reader_acquire(); - ValueHandleBase *Entry = (*ValueHandles)[Old]; - ValueHandlesLock->reader_release(); + LLVMContextImpl *pImpl = Old->getContext().pImpl; + ValueHandleBase *Entry = pImpl->ValueHandles[Old]; + assert(Entry && "Value bit set but no entries exist"); - - while (Entry) { - // Advance pointer to avoid invalidation. - ValueHandleBase *ThisNode = Entry; - Entry = Entry->Next; - - switch (ThisNode->getKind()) { + + // We use a local ValueHandleBase as an iterator so that + // ValueHandles can add and remove themselves from the list without + // breaking our iteration. This is not really an AssertingVH; we + // just have to give ValueHandleBase some kind. + for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) { + Iterator.RemoveFromUseList(); + Iterator.AddToExistingUseListAfter(Entry); + assert(Entry->Next == &Iterator && "Loop invariant broken."); + + switch (Entry->getKind()) { case Assert: // Asserting handle does not follow RAUW implicitly. break; + case Tracking: + // Tracking goes to new value like a WeakVH. Note that this may make it + // something incompatible with its templated type. We don't want to have a + // virtual (or inline) interface to handle this though, so instead we make + // the TrackingVH accessors guarantee that a client never sees this value. + + // FALLTHROUGH case Weak: // Weak goes to the new value, which will unlink it from Old's list. - ThisNode->operator=(New); + Entry->operator=(New); break; case Callback: // Forward to the subclass's implementation. - static_cast<CallbackVH*>(ThisNode)->allUsesReplacedWith(New); + static_cast<CallbackVH*>(Entry)->allUsesReplacedWith(New); break; } } @@ -580,7 +606,7 @@ void User::replaceUsesOfWith(Value *From, Value *To) { if (From == To) return; // Duh what? assert((!isa<Constant>(this) || isa<GlobalValue>(this)) && - "Cannot call User::replaceUsesofWith on a constant!"); + "Cannot call User::replaceUsesOfWith on a constant!"); for (unsigned i = 0, E = getNumOperands(); i != E; ++i) if (getOperand(i) == From) { // Is This operand is pointing to oldval? @@ -590,4 +616,3 @@ void User::replaceUsesOfWith(Value *From, Value *To) { setOperand(i, To); // Fix it now... } } - |