#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/GetElementPtrTypeIterator.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/LeakDetector.h"
#include "llvm/Support/ManagedStatic.h"
// Value Class
//===----------------------------------------------------------------------===//
-static inline const Type *checkType(const Type *Ty) {
+static inline Type *checkType(Type *Ty) {
assert(Ty && "Value defined with a null type: Error!");
- return Ty;
+ return const_cast<Type*>(Ty);
}
-Value::Value(const Type *ty, unsigned scid)
+Value::Value(Type *ty, unsigned scid)
: SubclassID(scid), HasValueHandle(0),
- SubclassOptionalData(0), SubclassData(0), VTy(checkType(ty)),
+ SubclassOptionalData(0), SubclassData(0), VTy((Type*)checkType(ty)),
UseList(0), Name(0) {
+ // FIXME: Why isn't this in the subclass gunk??
if (isa<CallInst>(this) || isa<InvokeInst>(this))
- assert((VTy->isFirstClassType() ||
- VTy == Type::getVoidTy(ty->getContext()) ||
- isa<OpaqueType>(ty) || VTy->getTypeID() == Type::StructTyID) &&
- "invalid CallInst type!");
+ assert((VTy->isFirstClassType() || VTy->isVoidTy() || VTy->isStructTy()) &&
+ "invalid CallInst type!");
else if (!isa<Constant>(this) && !isa<BasicBlock>(this))
- assert((VTy->isFirstClassType() ||
- VTy == Type::getVoidTy(ty->getContext()) ||
- isa<OpaqueType>(ty)) &&
+ assert((VTy->isFirstClassType() || VTy->isVoidTy()) &&
"Cannot create non-first-class values except for constants!");
}
// a <badref>
//
if (!use_empty()) {
- errs() << "While deleting: " << *VTy << " %" << getNameStr() << "\n";
+ dbgs() << "While deleting: " << *VTy << " %" << getName() << "\n";
for (use_iterator I = use_begin(), E = use_end(); I != E; ++I)
- errs() << "Use still stuck around after Def is destroyed:"
+ dbgs() << "Use still stuck around after Def is destroyed:"
<< **I << "\n";
}
#endif
// If this value is named, destroy the name. This should not be in a symtab
// at this point.
- if (Name)
+ if (Name && SubclassID != MDStringVal)
Name->Destroy();
// There should be no uses of this object anymore, remove it.
/// hasNUses - Return true if this Value has exactly N users.
///
bool Value::hasNUses(unsigned N) const {
- use_const_iterator UI = use_begin(), E = use_end();
+ const_use_iterator UI = use_begin(), E = use_end();
for (; N; --N, ++UI)
if (UI == E) return false; // Too few.
/// logically equivalent to getNumUses() >= N.
///
bool Value::hasNUsesOrMore(unsigned N) const {
- use_const_iterator UI = use_begin(), E = use_end();
+ const_use_iterator UI = use_begin(), E = use_end();
for (; N; --N, ++UI)
if (UI == E) return false; // Too few.
/// isUsedInBasicBlock - Return true if this value is used in the specified
/// basic block.
bool Value::isUsedInBasicBlock(const BasicBlock *BB) const {
- for (use_const_iterator I = use_begin(), E = use_end(); I != E; ++I) {
+ // Start by scanning over the instructions looking for a use before we start
+ // the expensive use iteration.
+ unsigned MaxBlockSize = 3;
+ for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
+ if (std::find(I->op_begin(), I->op_end(), this) != I->op_end())
+ return true;
+ if (MaxBlockSize-- == 0) // If the block is larger fall back to use_iterator
+ break;
+ }
+
+ if (MaxBlockSize != 0) // We scanned the entire block and found no use.
+ return false;
+
+ for (const_use_iterator I = use_begin(), E = use_end(); I != E; ++I) {
const Instruction *User = dyn_cast<Instruction>(*I);
if (User && User->getParent() == BB)
return true;
} else if (Argument *A = dyn_cast<Argument>(V)) {
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 if (isa<MDString>(V))
return true;
else {
return Name->getKey();
}
-std::string Value::getNameStr() const {
- return getName().str();
-}
-
void Value::setName(const Twine &NewName) {
+ assert(SubclassID != MDStringVal &&
+ "Cannot set the name of MDString with this method!");
+
// Fast path for common IRBuilder case of setName("") when there is no name.
if (NewName.isTriviallyEmpty() && !hasName())
return;
SmallString<256> NameData;
- NewName.toVector(NameData);
-
- const char *NameStr = NameData.data();
- unsigned NameLen = NameData.size();
+ StringRef NameRef = NewName.toStringRef(NameData);
// Name isn't changing?
- if (getName() == StringRef(NameStr, NameLen))
+ if (getName() == NameRef)
return;
- assert(getType() != Type::getVoidTy(getContext()) &&
- "Cannot assign a name to void values!");
+ assert(!getType()->isVoidTy() && "Cannot assign a name to void values!");
// Get the symbol table to update for this object.
ValueSymbolTable *ST;
return; // Cannot set a name on this value (e.g. constant).
if (!ST) { // No symbol table to update? Just do the change.
- if (NameLen == 0) {
+ if (NameRef.empty()) {
// Free the name for this value.
Name->Destroy();
Name = 0;
// then reallocated.
// Create the new name.
- Name = ValueName::Create(NameStr, NameStr+NameLen);
+ Name = ValueName::Create(NameRef.begin(), NameRef.end());
Name->setValue(this);
return;
}
Name->Destroy();
Name = 0;
- if (NameLen == 0)
+ if (NameRef.empty())
return;
}
// Name is changing to something new.
- Name = ST->createValueName(StringRef(NameStr, NameLen), this);
+ Name = ST->createValueName(NameRef, 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).
void Value::takeName(Value *V) {
+ assert(SubclassID != MDStringVal && "Cannot take the name of an MDString!");
+
ValueSymbolTable *ST = 0;
// If this value has a name, drop it.
if (hasName()) {
// 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;
+ assert(!Failure && "V has a name, so it should have a ST!"); (void)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.
}
-// uncheckedReplaceAllUsesWith - This is exactly the same as replaceAllUsesWith,
-// except that it doesn't have all of the asserts. The asserts fail because we
-// are half-way done resolving types, which causes some types to exist as two
-// different Type*'s at the same time. This is a sledgehammer to work around
-// this problem.
-//
-void Value::uncheckedReplaceAllUsesWith(Value *New) {
+void Value::replaceAllUsesWith(Value *New) {
+ assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
+ assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
+ assert(New->getType() == getType() &&
+ "replaceAllUses of value with new value of different type!");
+
// Notify all ValueHandles (if present) that this value is going away.
if (HasValueHandle)
ValueHandleBase::ValueIsRAUWd(this, New);
-
- // FIXME: It doesn't make sense at all for metadata to follow RAUW.
- if (Instruction *I = dyn_cast<Instruction>(this))
- if (I->hasMetadata()) {
- LLVMContext &Context = getContext();
- // FIXME: NUKE ValueIsRAUWd??
- Context.pImpl->TheMetadata.ValueIsRAUWd(this, New);
- }
-
+
while (!use_empty()) {
Use &U = *UseList;
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
continue;
}
}
-
+
U.set(New);
}
+
+ if (BasicBlock *BB = dyn_cast<BasicBlock>(this))
+ BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New));
}
-void Value::replaceAllUsesWith(Value *New) {
- assert(New && "Value::replaceAllUsesWith(<null>) is invalid!");
- assert(New != this && "this->replaceAllUsesWith(this) is NOT valid!");
- assert(New->getType() == getType() &&
- "replaceAllUses of value with new value of different type!");
+namespace {
+// Various metrics for how much to strip off of pointers.
+enum PointerStripKind {
+ PSK_ZeroIndices,
+ PSK_InBoundsConstantIndices,
+ PSK_InBounds
+};
- uncheckedReplaceAllUsesWith(New);
-}
+template <PointerStripKind StripKind>
+static Value *stripPointerCastsAndOffsets(Value *V) {
+ if (!V->getType()->isPointerTy())
+ return V;
-Value *Value::stripPointerCasts() {
- if (!isa<PointerType>(getType()))
- return this;
- Value *V = this;
+ // Even though we don't look through PHI nodes, we could be called on an
+ // instruction in an unreachable block, which may be on a cycle.
+ SmallPtrSet<Value *, 4> Visited;
+
+ Visited.insert(V);
do {
if (GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
- if (!GEP->hasAllZeroIndices())
- return V;
+ switch (StripKind) {
+ case PSK_ZeroIndices:
+ if (!GEP->hasAllZeroIndices())
+ return V;
+ break;
+ case PSK_InBoundsConstantIndices:
+ if (!GEP->hasAllConstantIndices())
+ return V;
+ // fallthrough
+ case PSK_InBounds:
+ if (!GEP->isInBounds())
+ return V;
+ break;
+ }
V = GEP->getPointerOperand();
} else if (Operator::getOpcode(V) == Instruction::BitCast) {
V = cast<Operator>(V)->getOperand(0);
} else {
return V;
}
- assert(isa<PointerType>(V->getType()) && "Unexpected operand type!");
- } while (1);
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V));
+
+ return V;
}
+} // namespace
-Value *Value::getUnderlyingObject() {
- if (!isa<PointerType>(getType()))
- return this;
- Value *V = this;
- unsigned MaxLookup = 6;
- do {
- 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 = GA->getAliasee();
- } else {
- return V;
+Value *Value::stripPointerCasts() {
+ return stripPointerCastsAndOffsets<PSK_ZeroIndices>(this);
+}
+
+Value *Value::stripInBoundsConstantOffsets() {
+ return stripPointerCastsAndOffsets<PSK_InBoundsConstantIndices>(this);
+}
+
+Value *Value::stripInBoundsOffsets() {
+ return stripPointerCastsAndOffsets<PSK_InBounds>(this);
+}
+
+/// isDereferenceablePointer - Test if this value is always a pointer to
+/// allocated and suitably aligned memory for a simple load or store.
+static bool isDereferenceablePointer(const Value *V,
+ SmallPtrSet<const Value *, 32> &Visited) {
+ // Note that it is not safe to speculate into a malloc'd region because
+ // malloc may return null.
+ // It's also not always safe to follow a bitcast, for example:
+ // bitcast i8* (alloca i8) to i32*
+ // would result in a 4-byte load from a 1-byte alloca. Some cases could
+ // be handled using DataLayout to check sizes and alignments though.
+
+ // These are obviously ok.
+ if (isa<AllocaInst>(V)) return true;
+
+ // Global variables which can't collapse to null are ok.
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
+ return !GV->hasExternalWeakLinkage();
+
+ // byval arguments are ok.
+ if (const Argument *A = dyn_cast<Argument>(V))
+ return A->hasByValAttr();
+
+ // For GEPs, determine if the indexing lands within the allocated object.
+ if (const GEPOperator *GEP = dyn_cast<GEPOperator>(V)) {
+ // Conservatively require that the base pointer be fully dereferenceable.
+ if (!Visited.insert(GEP->getOperand(0)))
+ return false;
+ if (!isDereferenceablePointer(GEP->getOperand(0), Visited))
+ return false;
+ // Check the indices.
+ gep_type_iterator GTI = gep_type_begin(GEP);
+ for (User::const_op_iterator I = GEP->op_begin()+1,
+ E = GEP->op_end(); I != E; ++I) {
+ Value *Index = *I;
+ Type *Ty = *GTI++;
+ // Struct indices can't be out of bounds.
+ if (isa<StructType>(Ty))
+ continue;
+ ConstantInt *CI = dyn_cast<ConstantInt>(Index);
+ if (!CI)
+ return false;
+ // Zero is always ok.
+ if (CI->isZero())
+ continue;
+ // Check to see that it's within the bounds of an array.
+ ArrayType *ATy = dyn_cast<ArrayType>(Ty);
+ if (!ATy)
+ return false;
+ if (CI->getValue().getActiveBits() > 64)
+ return false;
+ if (CI->getZExtValue() >= ATy->getNumElements())
+ return false;
}
- assert(isa<PointerType>(V->getType()) && "Unexpected operand type!");
- } while (--MaxLookup);
- return V;
+ // Indices check out; this is dereferenceable.
+ return true;
+ }
+
+ // If we don't know, assume the worst.
+ return false;
+}
+
+/// isDereferenceablePointer - Test if this value is always a pointer to
+/// allocated and suitably aligned memory for a simple load or store.
+bool Value::isDereferenceablePointer() const {
+ SmallPtrSet<const Value *, 32> Visited;
+ return ::isDereferenceablePointer(this, Visited);
}
/// DoPHITranslation - If this value is a PHI node with CurBB as its parent,
setPrevPtr(List);
if (Next) {
Next->setPrevPtr(&Next);
- assert(VP == Next->VP && "Added to wrong list?");
+ assert(VP.getPointer() == Next->VP.getPointer() && "Added to wrong list?");
}
}
/// AddToUseList - Add this ValueHandle to the use list for VP.
void ValueHandleBase::AddToUseList() {
- assert(VP && "Null pointer doesn't have a use list!");
+ assert(VP.getPointer() && "Null pointer doesn't have a use list!");
- LLVMContextImpl *pImpl = VP->getContext().pImpl;
+ LLVMContextImpl *pImpl = VP.getPointer()->getContext().pImpl;
- if (VP->HasValueHandle) {
+ if (VP.getPointer()->HasValueHandle) {
// If this value already has a ValueHandle, then it must be in the
// ValueHandles map already.
- ValueHandleBase *&Entry = pImpl->ValueHandles[VP];
+ ValueHandleBase *&Entry = pImpl->ValueHandles[VP.getPointer()];
assert(Entry != 0 && "Value doesn't have any handles?");
AddToExistingUseList(&Entry);
return;
DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
const void *OldBucketPtr = Handles.getPointerIntoBucketsArray();
- ValueHandleBase *&Entry = Handles[VP];
+ ValueHandleBase *&Entry = Handles[VP.getPointer()];
assert(Entry == 0 && "Value really did already have handles?");
AddToExistingUseList(&Entry);
- VP->HasValueHandle = true;
+ VP.getPointer()->HasValueHandle = true;
// If reallocation didn't happen or if this was the first insertion, don't
// walk the table.
// Okay, reallocation did happen. Fix the Prev Pointers.
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!");
+ assert(I->second && I->first == I->second->VP.getPointer() &&
+ "List invariant broken!");
I->second->setPrevPtr(&I->second);
}
}
/// RemoveFromUseList - Remove this ValueHandle from its current use list.
void ValueHandleBase::RemoveFromUseList() {
- assert(VP && VP->HasValueHandle && "Pointer doesn't have a use list!");
+ assert(VP.getPointer() && VP.getPointer()->HasValueHandle &&
+ "Pointer doesn't have a use list!");
// Unlink this from its use list.
ValueHandleBase **PrevPtr = getPrevPtr();
// 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.
- LLVMContextImpl *pImpl = VP->getContext().pImpl;
+ LLVMContextImpl *pImpl = VP.getPointer()->getContext().pImpl;
DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
if (Handles.isPointerIntoBucketsArray(PrevPtr)) {
- Handles.erase(VP);
- VP->HasValueHandle = false;
+ Handles.erase(VP.getPointer());
+ VP.getPointer()->HasValueHandle = false;
}
}
ValueHandleBase *Entry = pImpl->ValueHandles[V];
assert(Entry && "Value bit set but no entries exist");
- // 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.
+ // 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 a kind.
+ // Note that we deliberately do not the support the case when dropping a value
+ // handle results in a new value handle being permanently added to the list
+ // (as might occur in theory for CallbackVH's): the new value handle will not
+ // be processed and the checking code will mete out righteous punishment if
+ // the handle is still present once we have finished processing all the other
+ // value handles (it is fine to momentarily add then remove a value handle).
for (ValueHandleBase Iterator(Assert, *Entry); Entry; Entry = Iterator.Next) {
Iterator.RemoveFromUseList();
Iterator.AddToExistingUseListAfter(Entry);
// 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()
+ dbgs() << "While deleting: " << *V->getType() << " %" << V->getName()
<< "\n";
if (pImpl->ValueHandles[V]->getKind() == Assert)
llvm_unreachable("An asserting value handle still pointed to this"
break;
}
}
-}
-/// ~CallbackVH. Empty, but defined here to avoid emitting the vtable
-/// more than once.
-CallbackVH::~CallbackVH() {}
+#ifndef NDEBUG
+ // If any new tracking or weak value handles were added while processing the
+ // list, then complain about it now.
+ if (Old->HasValueHandle)
+ for (Entry = pImpl->ValueHandles[Old]; Entry; Entry = Entry->Next)
+ switch (Entry->getKind()) {
+ case Tracking:
+ case Weak:
+ dbgs() << "After RAUW from " << *Old->getType() << " %"
+ << Old->getName() << " to " << *New->getType() << " %"
+ << New->getName() << "\n";
+ llvm_unreachable("A tracking or weak value handle still pointed to the"
+ " old value!\n");
+ default:
+ break;
+ }
+#endif
+}
+// Default implementation for CallbackVH.
+void CallbackVH::allUsesReplacedWith(Value *) {}
-//===----------------------------------------------------------------------===//
-// User Class
-//===----------------------------------------------------------------------===//
-
-// replaceUsesOfWith - Replaces all references to the "From" definition with
-// references to the "To" definition.
-//
-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!");
-
- for (unsigned i = 0, E = getNumOperands(); i != E; ++i)
- if (getOperand(i) == From) { // Is This operand is pointing to oldval?
- // The side effects of this setOperand call include linking to
- // "To", adding "this" to the uses list of To, and
- // most importantly, removing "this" from the use list of "From".
- setOperand(i, To); // Fix it now...
- }
+void CallbackVH::deleted() {
+ setValPtr(NULL);
}
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