/3rd_party/llvm/include/llvm/ADT/TinyPtrVector.h
https://code.google.com/p/softart/ · C++ Header · 291 lines · 215 code · 42 blank · 34 comment · 74 complexity · 6c0b4b13c76628ee03591d5a14037994 MD5 · raw file
- //===- llvm/ADT/TinyPtrVector.h - 'Normally tiny' vectors -------*- C++ -*-===//
- //
- // The LLVM Compiler Infrastructure
- //
- // This file is distributed under the University of Illinois Open Source
- // License. See LICENSE.TXT for details.
- //
- //===----------------------------------------------------------------------===//
- #ifndef LLVM_ADT_TINYPTRVECTOR_H
- #define LLVM_ADT_TINYPTRVECTOR_H
- #include "llvm/ADT/ArrayRef.h"
- #include "llvm/ADT/PointerUnion.h"
- #include "llvm/ADT/STLExtras.h"
- #include "llvm/ADT/SmallVector.h"
- #include "llvm/Support/Compiler.h"
- namespace llvm {
-
- /// TinyPtrVector - This class is specialized for cases where there are
- /// normally 0 or 1 element in a vector, but is general enough to go beyond that
- /// when required.
- ///
- /// NOTE: This container doesn't allow you to store a null pointer into it.
- ///
- template <typename EltTy>
- class TinyPtrVector {
- public:
- typedef llvm::SmallVector<EltTy, 4> VecTy;
- typedef typename VecTy::value_type value_type;
- llvm::PointerUnion<EltTy, VecTy*> Val;
- TinyPtrVector() {}
- ~TinyPtrVector() {
- if (VecTy *V = Val.template dyn_cast<VecTy*>())
- delete V;
- }
- TinyPtrVector(const TinyPtrVector &RHS) : Val(RHS.Val) {
- if (VecTy *V = Val.template dyn_cast<VecTy*>())
- Val = new VecTy(*V);
- }
- TinyPtrVector &operator=(const TinyPtrVector &RHS) {
- if (this == &RHS)
- return *this;
- if (RHS.empty()) {
- this->clear();
- return *this;
- }
- // Try to squeeze into the single slot. If it won't fit, allocate a copied
- // vector.
- if (Val.template is<EltTy>()) {
- if (RHS.size() == 1)
- Val = RHS.front();
- else
- Val = new VecTy(*RHS.Val.template get<VecTy*>());
- return *this;
- }
- // If we have a full vector allocated, try to re-use it.
- if (RHS.Val.template is<EltTy>()) {
- Val.template get<VecTy*>()->clear();
- Val.template get<VecTy*>()->push_back(RHS.front());
- } else {
- *Val.template get<VecTy*>() = *RHS.Val.template get<VecTy*>();
- }
- return *this;
- }
- #if LLVM_HAS_RVALUE_REFERENCES
- TinyPtrVector(TinyPtrVector &&RHS) : Val(RHS.Val) {
- RHS.Val = (EltTy)0;
- }
- TinyPtrVector &operator=(TinyPtrVector &&RHS) {
- if (this == &RHS)
- return *this;
- if (RHS.empty()) {
- this->clear();
- return *this;
- }
- // If this vector has been allocated on the heap, re-use it if cheap. If it
- // would require more copying, just delete it and we'll steal the other
- // side.
- if (VecTy *V = Val.template dyn_cast<VecTy*>()) {
- if (RHS.Val.template is<EltTy>()) {
- V->clear();
- V->push_back(RHS.front());
- return *this;
- }
- delete V;
- }
- Val = RHS.Val;
- RHS.Val = (EltTy)0;
- return *this;
- }
- #endif
- // implicit conversion operator to ArrayRef.
- operator ArrayRef<EltTy>() const {
- if (Val.isNull())
- return ArrayRef<EltTy>();
- if (Val.template is<EltTy>())
- return *Val.getAddrOfPtr1();
- return *Val.template get<VecTy*>();
- }
- bool empty() const {
- // This vector can be empty if it contains no element, or if it
- // contains a pointer to an empty vector.
- if (Val.isNull()) return true;
- if (VecTy *Vec = Val.template dyn_cast<VecTy*>())
- return Vec->empty();
- return false;
- }
- unsigned size() const {
- if (empty())
- return 0;
- if (Val.template is<EltTy>())
- return 1;
- return Val.template get<VecTy*>()->size();
- }
- typedef const EltTy *const_iterator;
- typedef EltTy *iterator;
- iterator begin() {
- if (Val.template is<EltTy>())
- return Val.getAddrOfPtr1();
- return Val.template get<VecTy *>()->begin();
- }
- iterator end() {
- if (Val.template is<EltTy>())
- return begin() + (Val.isNull() ? 0 : 1);
- return Val.template get<VecTy *>()->end();
- }
- const_iterator begin() const {
- return (const_iterator)const_cast<TinyPtrVector*>(this)->begin();
- }
- const_iterator end() const {
- return (const_iterator)const_cast<TinyPtrVector*>(this)->end();
- }
- EltTy operator[](unsigned i) const {
- assert(!Val.isNull() && "can't index into an empty vector");
- if (EltTy V = Val.template dyn_cast<EltTy>()) {
- assert(i == 0 && "tinyvector index out of range");
- return V;
- }
- assert(i < Val.template get<VecTy*>()->size() &&
- "tinyvector index out of range");
- return (*Val.template get<VecTy*>())[i];
- }
- EltTy front() const {
- assert(!empty() && "vector empty");
- if (EltTy V = Val.template dyn_cast<EltTy>())
- return V;
- return Val.template get<VecTy*>()->front();
- }
- EltTy back() const {
- assert(!empty() && "vector empty");
- if (EltTy V = Val.template dyn_cast<EltTy>())
- return V;
- return Val.template get<VecTy*>()->back();
- }
- void push_back(EltTy NewVal) {
- assert(NewVal != 0 && "Can't add a null value");
- // If we have nothing, add something.
- if (Val.isNull()) {
- Val = NewVal;
- return;
- }
- // If we have a single value, convert to a vector.
- if (EltTy V = Val.template dyn_cast<EltTy>()) {
- Val = new VecTy();
- Val.template get<VecTy*>()->push_back(V);
- }
- // Add the new value, we know we have a vector.
- Val.template get<VecTy*>()->push_back(NewVal);
- }
- void pop_back() {
- // If we have a single value, convert to empty.
- if (Val.template is<EltTy>())
- Val = (EltTy)0;
- else if (VecTy *Vec = Val.template get<VecTy*>())
- Vec->pop_back();
- }
- void clear() {
- // If we have a single value, convert to empty.
- if (Val.template is<EltTy>()) {
- Val = (EltTy)0;
- } else if (VecTy *Vec = Val.template dyn_cast<VecTy*>()) {
- // If we have a vector form, just clear it.
- Vec->clear();
- }
- // Otherwise, we're already empty.
- }
- iterator erase(iterator I) {
- assert(I >= begin() && "Iterator to erase is out of bounds.");
- assert(I < end() && "Erasing at past-the-end iterator.");
- // If we have a single value, convert to empty.
- if (Val.template is<EltTy>()) {
- if (I == begin())
- Val = (EltTy)0;
- } else if (VecTy *Vec = Val.template dyn_cast<VecTy*>()) {
- // multiple items in a vector; just do the erase, there is no
- // benefit to collapsing back to a pointer
- return Vec->erase(I);
- }
- return end();
- }
- iterator erase(iterator S, iterator E) {
- assert(S >= begin() && "Range to erase is out of bounds.");
- assert(S <= E && "Trying to erase invalid range.");
- assert(E <= end() && "Trying to erase past the end.");
- if (Val.template is<EltTy>()) {
- if (S == begin() && S != E)
- Val = (EltTy)0;
- } else if (VecTy *Vec = Val.template dyn_cast<VecTy*>()) {
- return Vec->erase(S, E);
- }
- return end();
- }
- iterator insert(iterator I, const EltTy &Elt) {
- assert(I >= this->begin() && "Insertion iterator is out of bounds.");
- assert(I <= this->end() && "Inserting past the end of the vector.");
- if (I == end()) {
- push_back(Elt);
- return llvm::prior(end());
- }
- assert(!Val.isNull() && "Null value with non-end insert iterator.");
- if (EltTy V = Val.template dyn_cast<EltTy>()) {
- assert(I == begin());
- Val = Elt;
- push_back(V);
- return begin();
- }
- return Val.template get<VecTy*>()->insert(I, Elt);
- }
- template<typename ItTy>
- iterator insert(iterator I, ItTy From, ItTy To) {
- assert(I >= this->begin() && "Insertion iterator is out of bounds.");
- assert(I <= this->end() && "Inserting past the end of the vector.");
- if (From == To)
- return I;
- // If we have a single value, convert to a vector.
- ptrdiff_t Offset = I - begin();
- if (Val.isNull()) {
- if (llvm::next(From) == To) {
- Val = *From;
- return begin();
- }
- Val = new VecTy();
- } else if (EltTy V = Val.template dyn_cast<EltTy>()) {
- Val = new VecTy();
- Val.template get<VecTy*>()->push_back(V);
- }
- return Val.template get<VecTy*>()->insert(begin() + Offset, From, To);
- }
- };
- } // end namespace llvm
- #endif