llvm/lib/VMCore/Metadata.cpp

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//===-- Metadata.cpp - Implement Metadata classes -------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the Metadata classes.
//
//===----------------------------------------------------------------------===//
#include "LLVMContextImpl.h"
#include "llvm/Metadata.h"
#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Instruction.h"
#include "SymbolTableListTraitsImpl.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
//MetadataBase implementation
//
/// resizeOperands - Metadata keeps track of other metadata uses using
/// OperandList. Resize this list to hold anticipated number of metadata
/// operands.
void MetadataBase::resizeOperands(unsigned NumOps) {
unsigned e = getNumOperands();
if (NumOps == 0) {
NumOps = e*2;
if (NumOps < 2) NumOps = 2;
} else if (NumOps > NumOperands) {
// No resize needed.
if (ReservedSpace >= NumOps) return;
} else if (NumOps == NumOperands) {
if (ReservedSpace == NumOps) return;
} else {
return;
}
ReservedSpace = NumOps;
Use *OldOps = OperandList;
Use *NewOps = allocHungoffUses(NumOps);
std::copy(OldOps, OldOps + e, NewOps);
OperandList = NewOps;
if (OldOps) Use::zap(OldOps, OldOps + e, true);
}
//===----------------------------------------------------------------------===//
//MDString implementation
//
MDString *MDString::get(LLVMContext &Context, const StringRef &Str) {
LLVMContextImpl *pImpl = Context.pImpl;
sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
StringMapEntry<MDString *> &Entry =
pImpl->MDStringCache.GetOrCreateValue(Str);
MDString *&S = Entry.getValue();
if (!S) S = new MDString(Context, Entry.getKeyData(),
Entry.getKeyLength());
return S;
}
//===----------------------------------------------------------------------===//
//MDNode implementation
//
MDNode::MDNode(LLVMContext &C, Value*const* Vals, unsigned NumVals)
: MetadataBase(Type::getMetadataTy(C), Value::MDNodeVal) {
NumOperands = 0;
resizeOperands(NumVals);
for (unsigned i = 0; i != NumVals; ++i) {
// Only record metadata uses.
if (MetadataBase *MB = dyn_cast_or_null<MetadataBase>(Vals[i]))
OperandList[NumOperands++] = MB;
else if(Vals[i] &&
Vals[i]->getType()->getTypeID() == Type::MetadataTyID)
OperandList[NumOperands++] = Vals[i];
Node.push_back(ElementVH(Vals[i], this));
}
}
void MDNode::Profile(FoldingSetNodeID &ID) const {
for (const_elem_iterator I = elem_begin(), E = elem_end(); I != E; ++I)
ID.AddPointer(*I);
}
MDNode *MDNode::get(LLVMContext &Context, Value*const* Vals, unsigned NumVals) {
LLVMContextImpl *pImpl = Context.pImpl;
FoldingSetNodeID ID;
for (unsigned i = 0; i != NumVals; ++i)
ID.AddPointer(Vals[i]);
pImpl->ConstantsLock.reader_acquire();
void *InsertPoint;
MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
pImpl->ConstantsLock.reader_release();
if (!N) {
sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
if (!N) {
// InsertPoint will have been set by the FindNodeOrInsertPos call.
N = new MDNode(Context, Vals, NumVals);
pImpl->MDNodeSet.InsertNode(N, InsertPoint);
}
}
return N;
}
/// dropAllReferences - Remove all uses and clear node vector.
void MDNode::dropAllReferences() {
User::dropAllReferences();
Node.clear();
}
MDNode::~MDNode() {
{
LLVMContextImpl *pImpl = getType()->getContext().pImpl;
sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
pImpl->MDNodeSet.RemoveNode(this);
}
dropAllReferences();
}
// Replace value from this node's element list.
void MDNode::replaceElement(Value *From, Value *To) {
if (From == To || !getType())
return;
LLVMContext &Context = getType()->getContext();
LLVMContextImpl *pImpl = Context.pImpl;
// Find value. This is a linear search, do something if it consumes
// lot of time. It is possible that to have multiple instances of
// From in this MDNode's element list.
SmallVector<unsigned, 4> Indexes;
unsigned Index = 0;
for (SmallVector<ElementVH, 4>::iterator I = Node.begin(),
E = Node.end(); I != E; ++I, ++Index) {
Value *V = *I;
if (V && V == From)
Indexes.push_back(Index);
}
if (Indexes.empty())
return;
// Remove "this" from the context map.
{
sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
pImpl->MDNodeSet.RemoveNode(this);
}
// MDNode only lists metadata elements in operand list, because MDNode
// used by MDNode is considered a valid use. However on the side, MDNode
// using a non-metadata value is not considered a "use" of non-metadata
// value.
SmallVector<unsigned, 4> OpIndexes;
unsigned OpIndex = 0;
for (User::op_iterator OI = op_begin(), OE = op_end();
OI != OE; ++OI, OpIndex++) {
if (*OI == From)
OpIndexes.push_back(OpIndex);
}
if (MetadataBase *MDTo = dyn_cast_or_null<MetadataBase>(To)) {
for (SmallVector<unsigned, 4>::iterator OI = OpIndexes.begin(),
OE = OpIndexes.end(); OI != OE; ++OI)
setOperand(*OI, MDTo);
} else {
for (SmallVector<unsigned, 4>::iterator OI = OpIndexes.begin(),
OE = OpIndexes.end(); OI != OE; ++OI)
setOperand(*OI, 0);
}
// Replace From element(s) in place.
for (SmallVector<unsigned, 4>::iterator I = Indexes.begin(), E = Indexes.end();
I != E; ++I) {
unsigned Index = *I;
Node[Index] = ElementVH(To, this);
}
// Insert updated "this" into the context's folding node set.
// If a node with same element list already exist then before inserting
// updated "this" into the folding node set, replace all uses of existing
// node with updated "this" node.
FoldingSetNodeID ID;
Profile(ID);
pImpl->ConstantsLock.reader_acquire();
void *InsertPoint;
MDNode *N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
pImpl->ConstantsLock.reader_release();
if (N) {
N->replaceAllUsesWith(this);
delete N;
N = 0;
}
{
sys::SmartScopedWriter<true> Writer(pImpl->ConstantsLock);
N = pImpl->MDNodeSet.FindNodeOrInsertPos(ID, InsertPoint);
if (!N) {
// InsertPoint will have been set by the FindNodeOrInsertPos call.
N = this;
pImpl->MDNodeSet.InsertNode(N, InsertPoint);
}
}
}
//===----------------------------------------------------------------------===//
//NamedMDNode implementation
//
NamedMDNode::NamedMDNode(LLVMContext &C, const Twine &N,
MetadataBase*const* MDs,
unsigned NumMDs, Module *ParentModule)
: MetadataBase(Type::getMetadataTy(C), Value::NamedMDNodeVal), Parent(0) {
setName(N);
NumOperands = 0;
resizeOperands(NumMDs);
for (unsigned i = 0; i != NumMDs; ++i) {
if (MDs[i])
OperandList[NumOperands++] = MDs[i];
Node.push_back(WeakMetadataVH(MDs[i]));
}
if (ParentModule)
ParentModule->getNamedMDList().push_back(this);
}
NamedMDNode *NamedMDNode::Create(const NamedMDNode *NMD, Module *M) {
assert (NMD && "Invalid source NamedMDNode!");
SmallVector<MetadataBase *, 4> Elems;
for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i)
Elems.push_back(NMD->getElement(i));
return new NamedMDNode(NMD->getContext(), NMD->getName().data(),
Elems.data(), Elems.size(), M);
}
/// eraseFromParent - Drop all references and remove the node from parent
/// module.
void NamedMDNode::eraseFromParent() {
getParent()->getNamedMDList().erase(this);
}
/// dropAllReferences - Remove all uses and clear node vector.
void NamedMDNode::dropAllReferences() {
User::dropAllReferences();
Node.clear();
}
NamedMDNode::~NamedMDNode() {
dropAllReferences();
}
//===----------------------------------------------------------------------===//
//Metadata implementation
//
/// RegisterMDKind - Register a new metadata kind and return its ID.
/// A metadata kind can be registered only once.
MDKindID Metadata::RegisterMDKind(const char *Name) {
MDKindID Count = MDHandlerNames.size();
StringMap<unsigned>::iterator I = MDHandlerNames.find(Name);
assert(I == MDHandlerNames.end() && "Already registered MDKind!");
MDHandlerNames[Name] = Count + 1;
return Count + 1;
}
/// getMDKind - Return metadata kind. If the requested metadata kind
/// is not registered then return 0.
MDKindID Metadata::getMDKind(const char *Name) {
StringMap<unsigned>::iterator I = MDHandlerNames.find(Name);
if (I == MDHandlerNames.end())
return 0;
return I->getValue();
}
/// setMD - Attach the metadata of given kind with an Instruction.
void Metadata::setMD(MDKindID MDKind, MDNode *Node, Instruction *Inst) {
MDStoreTy::iterator I = MetadataStore.find(Inst);
Inst->HasMetadata = true;
if (I == MetadataStore.end()) {
MDMapTy Info;
Info.push_back(std::make_pair(MDKind, Node));
MetadataStore.insert(std::make_pair(Inst, Info));
return;
}
MDMapTy &Info = I->second;
Info.push_back(std::make_pair(MDKind, Node));
return;
}
/// getMD - Get the metadata of given kind attached with an Instruction.
/// If the metadata is not found then return 0.
MDNode *Metadata::getMD(MDKindID MDKind, const Instruction *Inst) {
MDNode *Node = NULL;
MDStoreTy::iterator I = MetadataStore.find(Inst);
if (I == MetadataStore.end())
return Node;
MDMapTy &Info = I->second;
for (MDMapTy::iterator I = Info.begin(), E = Info.end(); I != E; ++I)
if (I->first == MDKind)
Node = dyn_cast_or_null<MDNode>(I->second);
return Node;
}
/// getMDs - Get the metadata attached with an Instruction.
const Metadata::MDMapTy *Metadata::getMDs(const Instruction *Inst) {
MDStoreTy::iterator I = MetadataStore.find(Inst);
if (I == MetadataStore.end())
return NULL;
return &(I->second);
}
/// getHandlerNames - Get handler names. This is used by bitcode
/// writer.
const StringMap<unsigned> *Metadata::getHandlerNames() {
return &MDHandlerNames;
}
/// ValueIsDeleted - This handler is used to update metadata store
/// when a value is deleted.
void Metadata::ValueIsDeleted(const Instruction *Inst) {
// Find Metadata handles for this instruction.
MDStoreTy::iterator I = MetadataStore.find(Inst);
if (I == MetadataStore.end())
return;
MDMapTy &Info = I->second;
// FIXME : Give all metadata handlers a chance to adjust.
// Remove the entries for this instruction.
Info.clear();
MetadataStore.erase(Inst);
}
/// ValueIsCloned - This handler is used to update metadata store
/// when In1 is cloned to create In2.
void Metadata::ValueIsCloned(const Instruction *In1, Instruction *In2) {
// Find Metadata handles for In1.
MDStoreTy::iterator I = MetadataStore.find(In1);
if (I == MetadataStore.end())
return;
// FIXME : Give all metadata handlers a chance to adjust.
MDMapTy &In1Info = I->second;
MDMapTy In2Info;
for (MDMapTy::iterator I = In1Info.begin(), E = In1Info.end(); I != E; ++I)
if (MDNode *MD = dyn_cast_or_null<MDNode>(I->second))
setMD(I->first, MD, In2);
}