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| author | Ralf Luther <luther.ralf@gmail.com> | 2019-03-27 20:23:17 +0000 |
|---|---|---|
| committer | Gerrit Code Review <gerrit2@aicp-server-3> | 2019-03-27 20:23:17 +0000 |
| commit | 1ce3a9d272e564b22a1333a1e36a3d3ab7cfab01 (patch) | |
| tree | 391382eadd4fec5bb480f2e8934fa352770221d1 /clang-r353983/include/clang/Analysis/Support/BumpVector.h | |
| parent | d1d48b140bafaa8a50107292f5fce95562575765 (diff) | |
| parent | 4f56932d3416ac03f646bc1a611b3135fec2fe08 (diff) | |
Merge "Update prebuilt Clang to r353983." into p9.0HEADp9.0-backupp9.0
Diffstat (limited to 'clang-r353983/include/clang/Analysis/Support/BumpVector.h')
| -rw-r--r-- | clang-r353983/include/clang/Analysis/Support/BumpVector.h | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/clang-r353983/include/clang/Analysis/Support/BumpVector.h b/clang-r353983/include/clang/Analysis/Support/BumpVector.h new file mode 100644 index 00000000..74092dab --- /dev/null +++ b/clang-r353983/include/clang/Analysis/Support/BumpVector.h @@ -0,0 +1,256 @@ +//===- BumpVector.h - Vector-like ADT that uses bump allocation -*- C++ -*-===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// +// This file provides BumpVector, a vector-like ADT whose contents are +// allocated from a BumpPtrAllocator. +// +//===----------------------------------------------------------------------===// + +// FIXME: Most of this is copy-and-paste from SmallVector.h. We can +// refactor this core logic into something common that is shared between +// the two. The main thing that is different is the allocation strategy. + +#ifndef LLVM_CLANG_ANALYSIS_SUPPORT_BUMPVECTOR_H +#define LLVM_CLANG_ANALYSIS_SUPPORT_BUMPVECTOR_H + +#include "llvm/ADT/PointerIntPair.h" +#include "llvm/Support/Allocator.h" +#include <cassert> +#include <cstddef> +#include <cstring> +#include <iterator> +#include <memory> +#include <type_traits> + +namespace clang { + +class BumpVectorContext { + llvm::PointerIntPair<llvm::BumpPtrAllocator*, 1> Alloc; + +public: + /// Construct a new BumpVectorContext that creates a new BumpPtrAllocator + /// and destroys it when the BumpVectorContext object is destroyed. + BumpVectorContext() : Alloc(new llvm::BumpPtrAllocator(), 1) {} + + BumpVectorContext(BumpVectorContext &&Other) : Alloc(Other.Alloc) { + Other.Alloc.setInt(false); + Other.Alloc.setPointer(nullptr); + } + + /// Construct a new BumpVectorContext that reuses an existing + /// BumpPtrAllocator. This BumpPtrAllocator is not destroyed when the + /// BumpVectorContext object is destroyed. + BumpVectorContext(llvm::BumpPtrAllocator &A) : Alloc(&A, 0) {} + + ~BumpVectorContext() { + if (Alloc.getInt()) + delete Alloc.getPointer(); + } + + llvm::BumpPtrAllocator &getAllocator() { return *Alloc.getPointer(); } +}; + +template<typename T> +class BumpVector { + T *Begin = nullptr; + T *End = nullptr; + T *Capacity = nullptr; + +public: + // Default ctor - Initialize to empty. + explicit BumpVector(BumpVectorContext &C, unsigned N) { + reserve(C, N); + } + + ~BumpVector() { + if (std::is_class<T>::value) { + // Destroy the constructed elements in the vector. + destroy_range(Begin, End); + } + } + + using size_type = size_t; + using difference_type = ptrdiff_t; + using value_type = T; + using iterator = T *; + using const_iterator = const T *; + + using const_reverse_iterator = std::reverse_iterator<const_iterator>; + using reverse_iterator = std::reverse_iterator<iterator>; + + using reference = T &; + using const_reference = const T &; + using pointer = T *; + using const_pointer = const T *; + + // 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 (std::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, BumpVectorContext &C) { + if (End < Capacity) { + Retry: + new (End) T(Elt); + ++End; + return; + } + grow(C); + goto Retry; + } + + /// insert - Insert some number of copies of element into a position. Return + /// iterator to position after last inserted copy. + iterator insert(iterator I, size_t Cnt, const_reference E, + BumpVectorContext &C) { + assert(I >= Begin && I <= End && "Iterator out of bounds."); + if (End + Cnt <= Capacity) { + Retry: + move_range_right(I, End, Cnt); + construct_range(I, I + Cnt, E); + End += Cnt; + return I + Cnt; + } + ptrdiff_t D = I - Begin; + grow(C, size() + Cnt); + I = Begin + D; + goto Retry; + } + + void reserve(BumpVectorContext &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; } + +private: + /// grow - double the size of the allocated memory, guaranteeing space for at + /// least one more element or MinSize if specified. + void grow(BumpVectorContext &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(); + } + } + + void move_range_right(T *S, T *E, size_t D) { + for (T *I = E + D - 1, *IL = S + D - 1; I != IL; --I) { + --E; + new (I) T(*E); + E->~T(); + } + } +}; + +// Define this out-of-line to dissuade the C++ compiler from inlining it. +template <typename T> +void BumpVector<T>::grow(BumpVectorContext &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 BumpPtrAllocator. + T *NewElts = C.getAllocator().template Allocate<T>(NewCapacity); + + // Copy the elements over. + if (Begin != End) { + if (std::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)); + } + } + + // For now, leak 'Begin'. We can add it back to a freelist in + // BumpVectorContext. + Begin = NewElts; + End = NewElts+CurSize; + Capacity = Begin+NewCapacity; +} + +} // namespace clang + +#endif // LLVM_CLANG_ANALYSIS_SUPPORT_BUMPVECTOR_H |
