1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/js/src/jit/FixedList.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,86 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
1.5 + * vim: set ts=8 sts=4 et sw=4 tw=99:
1.6 + * This Source Code Form is subject to the terms of the Mozilla Public
1.7 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.8 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.9 +
1.10 +#ifndef jit_FixedList_h
1.11 +#define jit_FixedList_h
1.12 +
1.13 +#include <stddef.h>
1.14 +
1.15 +#include "jit/Ion.h"
1.16 +#include "jit/IonAllocPolicy.h"
1.17 +
1.18 +namespace js {
1.19 +namespace jit {
1.20 +
1.21 +// List of a fixed length, but the length is unknown until runtime.
1.22 +template <typename T>
1.23 +class FixedList
1.24 +{
1.25 + T *list_;
1.26 + size_t length_;
1.27 +
1.28 + private:
1.29 + FixedList(const FixedList&); // no copy definition.
1.30 + void operator= (const FixedList*); // no assignment definition.
1.31 +
1.32 + public:
1.33 + FixedList()
1.34 + : list_(nullptr), length_(0)
1.35 + { }
1.36 +
1.37 + // Dynamic memory allocation requires the ability to report failure.
1.38 + bool init(TempAllocator &alloc, size_t length) {
1.39 + length_ = length;
1.40 + if (length == 0)
1.41 + return true;
1.42 +
1.43 + if (length & mozilla::tl::MulOverflowMask<sizeof(T)>::value)
1.44 + return false;
1.45 + list_ = (T *)alloc.allocate(length * sizeof(T));
1.46 + return list_ != nullptr;
1.47 + }
1.48 +
1.49 + size_t length() const {
1.50 + return length_;
1.51 + }
1.52 +
1.53 + void shrink(size_t num) {
1.54 + JS_ASSERT(num < length_);
1.55 + length_ -= num;
1.56 + }
1.57 +
1.58 + bool growBy(TempAllocator &alloc, size_t num) {
1.59 + size_t newlength = length_ + num;
1.60 + if (newlength < length_)
1.61 + return false;
1.62 + if (newlength & mozilla::tl::MulOverflowMask<sizeof(T)>::value)
1.63 + return false;
1.64 + T *list = (T *)alloc.allocate((length_ + num) * sizeof(T));
1.65 + if (!list)
1.66 + return false;
1.67 +
1.68 + for (size_t i = 0; i < length_; i++)
1.69 + list[i] = list_[i];
1.70 +
1.71 + length_ += num;
1.72 + list_ = list;
1.73 + return true;
1.74 + }
1.75 +
1.76 + T &operator[](size_t index) {
1.77 + JS_ASSERT(index < length_);
1.78 + return list_[index];
1.79 + }
1.80 + const T &operator [](size_t index) const {
1.81 + JS_ASSERT(index < length_);
1.82 + return list_[index];
1.83 + }
1.84 +};
1.85 +
1.86 +} // namespace jit
1.87 +} // namespace js
1.88 +
1.89 +#endif /* jit_FixedList_h */
