//
//===----------------------------------------------------------------------===//
//
-// This file implements the Value and User classes.
+// This file implements the Value, ValueHandle, and User classes.
//
//===----------------------------------------------------------------------===//
+#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/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/ADT/DenseMap.h"
#include <algorithm>
using namespace llvm;
}
Value::Value(const Type *ty, unsigned scid)
- : SubclassID(scid), SubclassData(0), VTy(checkType(ty)),
+ : SubclassID(scid), HasValueHandle(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 ||
- isa<OpaqueType>(ty) || VTy->getTypeID() == Type::StructTyID) &&
+ assert((VTy->isFirstClassType() || VTy->isVoidTy() ||
+ ty->isOpaqueTy() || VTy->isStructTy()) &&
"invalid CallInst type!");
else if (!isa<Constant>(this) && !isa<BasicBlock>(this))
- assert((VTy->isFirstClassType() || VTy == Type::VoidTy ||
- isa<OpaqueType>(ty)) &&
+ assert((VTy->isFirstClassType() || VTy->isVoidTy() ||
+ ty->isOpaqueTy()) &&
"Cannot create non-first-class values except for constants!");
}
Value::~Value() {
+ // 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
// a <badref>
//
if (!use_empty()) {
- cerr << "While deleting: " << *VTy << " %" << getNameStr() << "\n";
+ dbgs() << "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:"
+ dbgs() << "Use still stuck around after Def is destroyed:"
<< **I << "\n";
}
#endif
// at this point.
if (Name)
Name->Destroy();
-
+
// There should be no uses of this object anymore, remove it.
LeakDetector::removeGarbageObject(this);
}
/// 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) {
+ 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;
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 {
+ } 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;
+ StringRef NameRef = NewName.toStringRef(NameData);
-std::string Value::getNameStr() const {
- if (Name == 0) return "";
- return std::string(Name->getKeyData(),
- Name->getKeyData()+Name->getKeyLength());
-}
-
-void Value::setName(const std::string &name) {
- setName(&name[0], name.size());
-}
+ // Name isn't changing?
+ if (getName() == NameRef)
+ return;
-void Value::setName(const char *Name) {
- setName(Name, Name ? strlen(Name) : 0);
-}
+ assert(!getType()->isVoidTy() && "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))
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;
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 = ValueName::Create(NameRef.begin(), NameRef.end());
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();
Name = 0;
- if (NameLen == 0)
+ if (NameRef.empty())
return;
}
// Name is changing to something new.
- Name = ST->createValueName(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).
+/// 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.
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) {
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);
}
// this problem.
//
void Value::uncheckedReplaceAllUsesWith(Value *New) {
+ // Notify all ValueHandles (if present) that this value is going away.
+ if (HasValueHandle)
+ ValueHandleBase::ValueIsRAUWd(this, New);
+
while (!use_empty()) {
Use &U = *UseList;
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
continue;
}
}
-
+
U.set(New);
}
}
}
Value *Value::stripPointerCasts() {
- if (!isa<PointerType>(getType()))
+ if (!getType()->isPointerTy())
return 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;
+
Value *V = this;
+ Visited.insert(V);
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;
}
- assert(isa<PointerType>(V->getType()) && "Unexpected operand type!");
- } while (1);
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ } while (Visited.insert(V));
+
+ return V;
}
-Value *Value::getUnderlyingObject() {
- if (!isa<PointerType>(getType()))
+Value *Value::getUnderlyingObject(unsigned MaxLookup) {
+ if (!getType()->isPointerTy())
return this;
Value *V = this;
- 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)
+ for (unsigned Count = 0; MaxLookup == 0 || Count < MaxLookup; ++Count) {
+ 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;
}
- assert(isa<PointerType>(V->getType()) && "Unexpected operand type!");
- } while (1);
+ assert(V->getType()->isPointerTy() && "Unexpected operand type!");
+ }
+ return V;
}
/// DoPHITranslation - If this value is a PHI node with CurBB as its parent,
/// 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)
return this;
}
+LLVMContext &Value::getContext() const { return VTy->getContext(); }
+
+//===----------------------------------------------------------------------===//
+// ValueHandleBase Class
+//===----------------------------------------------------------------------===//
+
+/// 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;
+ setPrevPtr(List);
+ if (Next) {
+ Next->setPrevPtr(&Next);
+ assert(VP == Next->VP && "Added to wrong 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.
+ 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.
+ 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) ||
+ Handles.size() == 1) {
+ return;
+ }
+
+ // 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!");
+ 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!");
+
+ // 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.
+ LLVMContextImpl *pImpl = VP->getContext().pImpl;
+ DenseMap<Value*, ValueHandleBase*> &Handles = pImpl->ValueHandles;
+ if (Handles.isPointerIntoBucketsArray(PrevPtr)) {
+ Handles.erase(VP);
+ VP->HasValueHandle = false;
+ }
+}
+
+
+void ValueHandleBase::ValueIsDeleted(Value *V) {
+ assert(V->HasValueHandle && "Should only be called if ValueHandles present");
+
+ // Get the linked list base, which is guaranteed to exist since the
+ // HasValueHandle flag is set.
+ LLVMContextImpl *pImpl = V->getContext().pImpl;
+ 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 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);
+ assert(Entry->Next == &Iterator && "Loop invariant broken.");
+
+ switch (Entry->getKind()) {
+ case Assert:
+ 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.
+ Entry->operator=(0);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(Entry)->deleted();
+ break;
+ }
+ }
+
+ // All callbacks, weak references, and assertingVHs should be dropped by now.
+ if (V->HasValueHandle) {
+#ifndef NDEBUG // Only in +Asserts mode...
+ dbgs() << "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.
+ LLVMContextImpl *pImpl = Old->getContext().pImpl;
+ ValueHandleBase *Entry = pImpl->ValueHandles[Old];
+
+ 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.
+ 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.
+ Entry->operator=(New);
+ break;
+ case Callback:
+ // Forward to the subclass's implementation.
+ static_cast<CallbackVH*>(Entry)->allUsesReplacedWith(New);
+ break;
+ }
+ }
+
+#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->getNameStr() << " to " << *New->getType() << " %"
+ << New->getNameStr() << "\n";
+ llvm_unreachable("A tracking or weak value handle still pointed to the"
+ " old value!\n");
+ default:
+ break;
+ }
+#endif
+}
+
+/// ~CallbackVH. Empty, but defined here to avoid emitting the vtable
+/// more than once.
+CallbackVH::~CallbackVH() {}
+
//===----------------------------------------------------------------------===//
// User Class
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?
setOperand(i, To); // Fix it now...
}
}
-
projects / oota-llvm.git / blobdiff