[cfe-commits] r101194 - /cfe/trunk/include/clang/AST/ASTVector.h

Chris Lattner clattner at apple.com
Tue Apr 13 20:39:48 PDT 2010


On Apr 13, 2010, at 4:39 PM, Ted Kremenek wrote:

> Author: kremenek
> Date: Tue Apr 13 18:39:09 2010
> New Revision: 101194
> 
> URL: http://llvm.org/viewvc/llvm-project?rev=101194&view=rev
> Log:
> Introduce ASTVector, which is a std::vector-like class that allocates all memory
> using the allocator associated with an ASTContext.  This is largely copy-and-paste
> from SmallVector, and should be refactored one day.

It shouldn't be too hard to make SmallVector use an Allocator, would it?

-Chris

> 
> Added:
>    cfe/trunk/include/clang/AST/ASTVector.h
> 
> Added: cfe/trunk/include/clang/AST/ASTVector.h
> URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/ASTVector.h?rev=101194&view=auto
> ==============================================================================
> --- cfe/trunk/include/clang/AST/ASTVector.h (added)
> +++ cfe/trunk/include/clang/AST/ASTVector.h Tue Apr 13 18:39:09 2010
> @@ -0,0 +1,393 @@
> +//===- ASTVector.h - Vector that uses ASTContext for allocation  --*- C++ -*-=//
> +//
> +//                     The LLVM Compiler Infrastructure
> +//
> +// This file is distributed under the University of Illinois Open Source
> +// License. See LICENSE.TXT for details.
> +//
> +//===----------------------------------------------------------------------===//
> +//
> +//  This file provides ASTVector, a vector  ADT whose contents are
> +//  allocated using the allocator associated with an ASTContext..
> +//
> +//===----------------------------------------------------------------------===//
> +
> +// FIXME: Most of this is copy-and-paste from BumpVector.h and SmallVector.h.
> +// We can refactor this core logic into something common.
> +
> +#ifndef LLVM_CLANG_AST_VECTOR
> +#define LLVM_CLANG_AST_VECTOR
> +
> +#include "llvm/Support/type_traits.h"
> +#include "llvm/Support/Allocator.h"
> +#include "llvm/ADT/PointerIntPair.h"
> +#include <algorithm>
> +#include <memory>
> +#include <cstring>
> +
> +#ifdef _MSC_VER
> +namespace std {
> +#if _MSC_VER <= 1310
> +  // Work around flawed VC++ implementation of std::uninitialized_copy.  Define
> +  // additional overloads so that elements with pointer types are recognized as
> +  // scalars and not objects, causing bizarre type conversion errors.
> +  template<class T1, class T2>
> +  inline _Scalar_ptr_iterator_tag _Ptr_cat(T1 **, T2 **) {
> +    _Scalar_ptr_iterator_tag _Cat;
> +    return _Cat;
> +  }
> +
> +  template<class T1, class T2>
> +  inline _Scalar_ptr_iterator_tag _Ptr_cat(T1* const *, T2 **) {
> +    _Scalar_ptr_iterator_tag _Cat;
> +    return _Cat;
> +  }
> +#else
> +  // FIXME: It is not clear if the problem is fixed in VS 2005.  What is clear
> +  // is that the above hack won't work if it wasn't fixed.
> +#endif
> +}
> +#endif
> +
> +namespace clang {
> +
> +template<typename T>
> +class ASTVector {
> +  T *Begin, *End, *Capacity;
> +
> +  void setEnd(T *P) { this->End = P; }
> +
> +public:
> +  // Default ctor - Initialize to empty.
> +  explicit ASTVector(ASTContext &C, unsigned N = 0)
> +  : Begin(NULL), End(NULL), Capacity(NULL) {
> +    reserve(C, N);
> +  }
> +
> +  ~ASTVector() {
> +    if (llvm::is_class<T>::value) {
> +      // Destroy the constructed elements in the vector.
> +      destroy_range(Begin, End);
> +    }
> +  }
> +
> +  typedef size_t size_type;
> +  typedef ptrdiff_t difference_type;
> +  typedef T value_type;
> +  typedef T* iterator;
> +  typedef const T* const_iterator;
> +
> +  typedef std::reverse_iterator<const_iterator>  const_reverse_iterator;
> +  typedef std::reverse_iterator<iterator>  reverse_iterator;
> +
> +  typedef T& reference;
> +  typedef const T& const_reference;
> +  typedef T* pointer;
> +  typedef const T* const_pointer;
> +
> +  // forward iterator creation methods.
> +  iterator begin() { return Begin; }
> +  const_iterator begin() const { return Begin; }
> +  iterator end() { return End; }
> +  const_iterator end() const { return End; }
> +
> +  // reverse iterator creation methods.
> +  reverse_iterator rbegin()            { return reverse_iterator(end()); }
> +  const_reverse_iterator rbegin() const{ return const_reverse_iterator(end()); }
> +  reverse_iterator rend()              { return reverse_iterator(begin()); }
> +  const_reverse_iterator rend() const { return const_reverse_iterator(begin());}
> +
> +  bool empty() const { return Begin == End; }
> +  size_type size() const { return End-Begin; }
> +
> +  reference operator[](unsigned idx) {
> +    assert(Begin + idx < End);
> +    return Begin[idx];
> +  }
> +  const_reference operator[](unsigned idx) const {
> +    assert(Begin + idx < End);
> +    return Begin[idx];
> +  }
> +
> +  reference front() {
> +    return begin()[0];
> +  }
> +  const_reference front() const {
> +    return begin()[0];
> +  }
> +
> +  reference back() {
> +    return end()[-1];
> +  }
> +  const_reference back() const {
> +    return end()[-1];
> +  }
> +
> +  void pop_back() {
> +    --End;
> +    End->~T();
> +  }
> +
> +  T pop_back_val() {
> +    T Result = back();
> +    pop_back();
> +    return Result;
> +  }
> +
> +  void clear() {
> +    if (llvm::is_class<T>::value) {
> +      destroy_range(Begin, End);
> +    }
> +    End = Begin;
> +  }
> +
> +  /// data - Return a pointer to the vector's buffer, even if empty().
> +  pointer data() {
> +    return pointer(Begin);
> +  }
> +
> +  /// data - Return a pointer to the vector's buffer, even if empty().
> +  const_pointer data() const {
> +    return const_pointer(Begin);
> +  }
> +
> +  void push_back(const_reference Elt, ASTContext &C) {
> +    if (End < Capacity) {
> +    Retry:
> +      new (End) T(Elt);
> +      ++End;
> +      return;
> +    }
> +    grow(C);
> +    goto Retry;
> +  }
> +
> +  void reserve(ASTContext &C, unsigned N) {
> +    if (unsigned(Capacity-Begin) < N)
> +      grow(C, N);
> +  }
> +
> +  /// capacity - Return the total number of elements in the currently allocated
> +  /// buffer.
> +  size_t capacity() const { return Capacity - Begin; }
> +
> +  /// append - Add the specified range to the end of the SmallVector.
> +  ///
> +  template<typename in_iter>
> +  void append(ASTContext &C, in_iter in_start, in_iter in_end) {
> +    size_type NumInputs = std::distance(in_start, in_end);
> +    // Grow allocated space if needed.
> +    if (NumInputs > size_type(this->capacity_ptr()-this->end()))
> +      this->grow(C, this->size()+NumInputs);
> +
> +    // Copy the new elements over.
> +    // TODO: NEED To compile time dispatch on whether in_iter is a random access
> +    // iterator to use the fast uninitialized_copy.
> +    std::uninitialized_copy(in_start, in_end, this->end());
> +    this->setEnd(this->end() + NumInputs);
> +  }
> +
> +  /// append - Add the specified range to the end of the SmallVector.
> +  ///
> +  void append(ASTContext &C, size_type NumInputs, const T &Elt) {
> +    // Grow allocated space if needed.
> +    if (NumInputs > size_type(this->capacity_ptr()-this->end()))
> +      this->grow(C, this->size()+NumInputs);
> +
> +    // Copy the new elements over.
> +    std::uninitialized_fill_n(this->end(), NumInputs, Elt);
> +    this->setEnd(this->end() + NumInputs);
> +  }
> +
> +  /// uninitialized_copy - Copy the range [I, E) onto the uninitialized memory
> +  /// starting with "Dest", constructing elements into it as needed.
> +  template<typename It1, typename It2>
> +  static void uninitialized_copy(It1 I, It1 E, It2 Dest) {
> +    std::uninitialized_copy(I, E, Dest);
> +  }
> +
> +  iterator insert(ASTContext &C, iterator I, const T &Elt) {
> +    if (I == this->end()) {  // Important special case for empty vector.
> +      push_back(Elt);
> +      return this->end()-1;
> +    }
> +
> +    if (this->EndX < this->CapacityX) {
> +    Retry:
> +      new (this->end()) T(this->back());
> +      this->setEnd(this->end()+1);
> +      // Push everything else over.
> +      std::copy_backward(I, this->end()-1, this->end());
> +      *I = Elt;
> +      return I;
> +    }
> +    size_t EltNo = I-this->begin();
> +    this->grow(C);
> +    I = this->begin()+EltNo;
> +    goto Retry;
> +  }
> +
> +  iterator insert(ASTContext &C, iterator I, size_type NumToInsert,
> +                  const T &Elt) {
> +    if (I == this->end()) {  // Important special case for empty vector.
> +      append(C, NumToInsert, Elt);
> +      return this->end()-1;
> +    }
> +
> +    // Convert iterator to elt# to avoid invalidating iterator when we reserve()
> +    size_t InsertElt = I - this->begin();
> +
> +    // Ensure there is enough space.
> +    reserve(C, static_cast<unsigned>(this->size() + NumToInsert));
> +
> +    // Uninvalidate the iterator.
> +    I = this->begin()+InsertElt;
> +
> +    // If there are more elements between the insertion point and the end of the
> +    // range than there are being inserted, we can use a simple approach to
> +    // insertion.  Since we already reserved space, we know that this won't
> +    // reallocate the vector.
> +    if (size_t(this->end()-I) >= NumToInsert) {
> +      T *OldEnd = this->end();
> +      append(C, this->end()-NumToInsert, this->end());
> +
> +      // Copy the existing elements that get replaced.
> +      std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
> +
> +      std::fill_n(I, NumToInsert, Elt);
> +      return I;
> +    }
> +
> +    // Otherwise, we're inserting more elements than exist already, and we're
> +    // not inserting at the end.
> +
> +    // Copy over the elements that we're about to overwrite.
> +    T *OldEnd = this->end();
> +    this->setEnd(this->end() + NumToInsert);
> +    size_t NumOverwritten = OldEnd-I;
> +    this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
> +
> +    // Replace the overwritten part.
> +    std::fill_n(I, NumOverwritten, Elt);
> +
> +    // Insert the non-overwritten middle part.
> +    std::uninitialized_fill_n(OldEnd, NumToInsert-NumOverwritten, Elt);
> +    return I;
> +  }
> +
> +  template<typename ItTy>
> +  iterator insert(ASTContext &C, iterator I, ItTy From, ItTy To) {
> +    if (I == this->end()) {  // Important special case for empty vector.
> +      append(C, From, To);
> +      return this->end()-1;
> +    }
> +
> +    size_t NumToInsert = std::distance(From, To);
> +    // Convert iterator to elt# to avoid invalidating iterator when we reserve()
> +    size_t InsertElt = I - this->begin();
> +
> +    // Ensure there is enough space.
> +    reserve(C, static_cast<unsigned>(this->size() + NumToInsert));
> +
> +    // Uninvalidate the iterator.
> +    I = this->begin()+InsertElt;
> +
> +    // If there are more elements between the insertion point and the end of the
> +    // range than there are being inserted, we can use a simple approach to
> +    // insertion.  Since we already reserved space, we know that this won't
> +    // reallocate the vector.
> +    if (size_t(this->end()-I) >= NumToInsert) {
> +      T *OldEnd = this->end();
> +      append(C, this->end()-NumToInsert, this->end());
> +
> +      // Copy the existing elements that get replaced.
> +      std::copy_backward(I, OldEnd-NumToInsert, OldEnd);
> +
> +      std::copy(From, To, I);
> +      return I;
> +    }
> +
> +    // Otherwise, we're inserting more elements than exist already, and we're
> +    // not inserting at the end.
> +
> +    // Copy over the elements that we're about to overwrite.
> +    T *OldEnd = this->end();
> +    this->setEnd(this->end() + NumToInsert);
> +    size_t NumOverwritten = OldEnd-I;
> +    this->uninitialized_copy(I, OldEnd, this->end()-NumOverwritten);
> +
> +    // Replace the overwritten part.
> +    for (; NumOverwritten > 0; --NumOverwritten) {
> +      *I = *From;
> +      ++I; ++From;
> +    }
> +
> +    // Insert the non-overwritten middle part.
> +    this->uninitialized_copy(From, To, OldEnd);
> +    return I;
> +  }
> +
> +  void resize(ASTContext &C, unsigned N, const T &NV) {
> +    if (N < this->size()) {
> +      this->destroy_range(this->begin()+N, this->end());
> +      this->setEnd(this->begin()+N);
> +    } else if (N > this->size()) {
> +      if (this->capacity() < N)
> +        this->grow(C, N);
> +      construct_range(this->end(), this->begin()+N, NV);
> +      this->setEnd(this->begin()+N);
> +    }
> +  }
> +
> +private:
> +  /// grow - double the size of the allocated memory, guaranteeing space for at
> +  /// least one more element or MinSize if specified.
> +  void grow(ASTContext &C, size_type MinSize = 1);
> +
> +  void construct_range(T *S, T *E, const T &Elt) {
> +    for (; S != E; ++S)
> +      new (S) T(Elt);
> +  }
> +
> +  void destroy_range(T *S, T *E) {
> +    while (S != E) {
> +      --E;
> +      E->~T();
> +    }
> +  }
> +
> +protected:
> +  iterator capacity_ptr() { return (iterator)this->Capacity; }
> +};
> +
> +// Define this out-of-line to dissuade the C++ compiler from inlining it.
> +template <typename T>
> +void ASTVector<T>::grow(ASTContext &C, size_t MinSize) {
> +  size_t CurCapacity = Capacity-Begin;
> +  size_t CurSize = size();
> +  size_t NewCapacity = 2*CurCapacity;
> +  if (NewCapacity < MinSize)
> +    NewCapacity = MinSize;
> +
> +  // Allocate the memory from the ASTContext.
> +  T *NewElts = new (C) T[NewCapacity];
> +
> +  // Copy the elements over.
> +  if (llvm::is_class<T>::value) {
> +    std::uninitialized_copy(Begin, End, NewElts);
> +    // Destroy the original elements.
> +    destroy_range(Begin, End);
> +  }
> +  else {
> +    // Use memcpy for PODs (std::uninitialized_copy optimizes to memmove).
> +    memcpy(NewElts, Begin, CurSize * sizeof(T));
> +  }
> +
> +  C.Deallocate(Begin);
> +  Begin = NewElts;
> +  End = NewElts+CurSize;
> +  Capacity = Begin+NewCapacity;
> +}
> +
> +} // end: clang namespace
> +#endif
> 
> 
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