#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->isVoidTy() ||
- ty->isOpaqueTy() || VTy->isStructTy()) &&
- "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->isVoidTy() ||
- ty->isOpaqueTy()) &&
+ assert((VTy->isFirstClassType() || VTy->isVoidTy()) &&
"Cannot create non-first-class values except for constants!");
}
// 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);
-
+
while (!use_empty()) {
Use &U = *UseList;
// Must handle Constants specially, we cannot call replaceUsesOfWith on a
continue;
}
}
-
+
U.set(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!");
-
- uncheckedReplaceAllUsesWith(New);
+
+ if (BasicBlock *BB = dyn_cast<BasicBlock>(this))
+ BB->replaceSuccessorsPhiUsesWith(cast<BasicBlock>(New));
}
Value *Value::stripPointerCasts() {
return V;
}
-Value *Value::getUnderlyingObject(unsigned MaxLookup) {
- if (!getType()->isPointerTy())
- return this;
- Value *V = this;
- 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 = GA->getAliasee();
- } else {
- return V;
+/// 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 {
+ // 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 TargetData to check sizes and alignments though.
+
+ // These are obviously ok.
+ if (isa<AllocaInst>(this)) return true;
+
+ // Global variables which can't collapse to null are ok.
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(this))
+ return !GV->hasExternalWeakLinkage();
+
+ // byval arguments are ok.
+ if (const Argument *A = dyn_cast<Argument>(this))
+ return A->hasByValAttr();
+
+ // For GEPs, determine if the indexing lands within the allocated object.
+ if (const GEPOperator *GEP = dyn_cast<GEPOperator>(this)) {
+ // Conservatively require that the base pointer be fully dereferenceable.
+ if (!GEP->getOperand(0)->isDereferenceablePointer())
+ 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(V->getType()->isPointerTy() && "Unexpected operand type!");
+ // Indices check out; this is dereferenceable.
+ return true;
}
- return V;
+
+ // If we don't know, assume the worst.
+ return false;
}
/// DoPHITranslation - If this value is a PHI node with CurBB as its parent,
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);
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
-//===----------------------------------------------------------------------===//
-
-// 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...
- }
-}
projects / oota-llvm.git / blobdiff