diff options
-rw-r--r-- | xpcom/glue/nsTArray-inl.h | 32 | ||||
-rw-r--r-- | xpcom/glue/nsTArray.h | 42 |
2 files changed, 50 insertions, 24 deletions
diff --git a/xpcom/glue/nsTArray-inl.h b/xpcom/glue/nsTArray-inl.h index af57c9866..7e667a327 100644 --- a/xpcom/glue/nsTArray-inl.h +++ b/xpcom/glue/nsTArray-inl.h @@ -111,6 +111,23 @@ bool IsTwiceTheRequiredBytesRepresentableAsUint32(size_t aCapacity, template<class Alloc, class Copy> template<typename ActualAlloc> typename ActualAlloc::ResultTypeProxy +nsTArray_base<Alloc, Copy>::ExtendCapacity(size_type aLength, + size_type aCount, + size_type aElemSize) +{ + mozilla::CheckedInt<size_type> newLength = aLength; + newLength += aCount; + + if (!newLength.isValid()) { + return ActualAlloc::FailureResult(); + } + + return this->EnsureCapacity<ActualAlloc>(newLength.value(), aElemSize); +} + +template<class Alloc, class Copy> +template<typename ActualAlloc> +typename ActualAlloc::ResultTypeProxy nsTArray_base<Alloc, Copy>::EnsureCapacity(size_type aCapacity, size_type aElemSize) { @@ -275,26 +292,21 @@ nsTArray_base<Alloc, Copy>::ShiftData(index_type aStart, template<class Alloc, class Copy> template<typename ActualAlloc> -bool +typename ActualAlloc::ResultTypeProxy nsTArray_base<Alloc, Copy>::InsertSlotsAt(index_type aIndex, size_type aCount, size_type aElemSize, size_t aElemAlign) { MOZ_ASSERT(aIndex <= Length(), "Bogus insertion index"); - size_type newLen = Length() + aCount; - - EnsureCapacity<ActualAlloc>(newLen, aElemSize); - - // Check for out of memory conditions - if (Capacity() < newLen) { - return false; + if (!ActualAlloc::Successful(this->ExtendCapacity<ActualAlloc>(Length(), aCount, aElemSize))) { + return ActualAlloc::FailureResult(); } - + // Move the existing elements as needed. Note that this will // change our mLength, so no need to call IncrementLength. ShiftData<ActualAlloc>(aIndex, 0, aCount, aElemSize, aElemAlign); - return true; + return ActualAlloc::SuccessResult(); } // nsTArray_base::IsAutoArrayRestorer is an RAII class which takes diff --git a/xpcom/glue/nsTArray.h b/xpcom/glue/nsTArray.h index c86772a8e..82586a79a 100644 --- a/xpcom/glue/nsTArray.h +++ b/xpcom/glue/nsTArray.h @@ -12,6 +12,7 @@ #include "mozilla/Assertions.h" #include "mozilla/Attributes.h" #include "mozilla/BinarySearch.h" +#include "mozilla/CheckedInt.h" #include "mozilla/fallible.h" #include "mozilla/Function.h" #include "mozilla/MathAlgorithms.h" @@ -421,6 +422,17 @@ protected: typename ActualAlloc::ResultTypeProxy EnsureCapacity(size_type aCapacity, size_type aElemSize); + // Extend the storage to accommodate aCount extra elements. + // @param aLength The current size of the array. + // @param aCount The number of elements to add. + // @param aElemSize The size of an array element. + // @return False if insufficient memory is available or the new length + // would overflow; true otherwise. + template<typename ActualAlloc> + typename ActualAlloc::ResultTypeProxy ExtendCapacity(size_type aLength, + size_type aCount, + size_type aElemSize); + // Tries to resize the storage to the minimum required amount. If this fails, // the array is left as-is. // @param aElemSize The size of an array element. @@ -462,8 +474,9 @@ protected: // @param aElementSize the size of an array element. // @param aElemAlign the alignment in bytes of an array element. template<typename ActualAlloc> - bool InsertSlotsAt(index_type aIndex, size_type aCount, - size_type aElementSize, size_t aElemAlign); + typename ActualAlloc::ResultTypeProxy + InsertSlotsAt(index_type aIndex, size_type aCount, + size_type aElementSize, size_t aElemAlign); template<typename ActualAlloc, class Allocator> typename ActualAlloc::ResultTypeProxy @@ -1655,8 +1668,8 @@ public: protected: template<typename ActualAlloc = Alloc> elem_type* AppendElements(size_type aCount) { - if (!ActualAlloc::Successful(this->template EnsureCapacity<ActualAlloc>( - Length() + aCount, sizeof(elem_type)))) { + if (!ActualAlloc::Successful(this->template ExtendCapacity<ActualAlloc>( + Length(), aCount, sizeof(elem_type)))) { return nullptr; } elem_type* elems = Elements() + Length(); @@ -1872,9 +1885,8 @@ protected: template<typename ActualAlloc = Alloc> elem_type* InsertElementsAt(index_type aIndex, size_type aCount) { - if (!base_type::template InsertSlotsAt<ActualAlloc>(aIndex, aCount, - sizeof(elem_type), - MOZ_ALIGNOF(elem_type))) { + if (!ActualAlloc::Successful(this->template InsertSlotsAt<ActualAlloc>( + aIndex, aCount, sizeof(elem_type), MOZ_ALIGNOF(elem_type)))) { return nullptr; } @@ -2047,9 +2059,8 @@ auto nsTArray_Impl<E, Alloc>::InsertElementsAt(index_type aIndex, size_type aCount, const Item& aItem) -> elem_type* { - if (!base_type::template InsertSlotsAt<ActualAlloc>(aIndex, aCount, - sizeof(elem_type), - MOZ_ALIGNOF(elem_type))) { + if (!ActualAlloc::Successful(this->template InsertSlotsAt<ActualAlloc>( + aIndex, aCount, sizeof(elem_type), MOZ_ALIGNOF(elem_type)))) { return nullptr; } @@ -2068,6 +2079,7 @@ template<typename ActualAlloc> auto nsTArray_Impl<E, Alloc>::InsertElementAt(index_type aIndex) -> elem_type* { + // Length() + 1 is guaranteed to not overflow, so EnsureCapacity is OK. if (!ActualAlloc::Successful(this->template EnsureCapacity<ActualAlloc>( Length() + 1, sizeof(elem_type)))) { return nullptr; @@ -2084,6 +2096,7 @@ template<class Item, typename ActualAlloc> auto nsTArray_Impl<E, Alloc>::InsertElementAt(index_type aIndex, Item&& aItem) -> elem_type* { + // Length() + 1 is guaranteed to not overflow, so EnsureCapacity is OK. if (!ActualAlloc::Successful(this->template EnsureCapacity<ActualAlloc>( Length() + 1, sizeof(elem_type)))) { return nullptr; @@ -2100,8 +2113,8 @@ template<class Item, typename ActualAlloc> auto nsTArray_Impl<E, Alloc>::AppendElements(const Item* aArray, size_type aArrayLen) -> elem_type* { - if (!ActualAlloc::Successful(this->template EnsureCapacity<ActualAlloc>( - Length() + aArrayLen, sizeof(elem_type)))) { + if (!ActualAlloc::Successful(this->template ExtendCapacity<ActualAlloc>( + Length(), aArrayLen, sizeof(elem_type)))) { return nullptr; } index_type len = Length(); @@ -2123,8 +2136,8 @@ nsTArray_Impl<E, Alloc>::AppendElements(nsTArray_Impl<Item, Allocator>&& aArray) index_type len = Length(); index_type otherLen = aArray.Length(); - if (!Alloc::Successful(this->template EnsureCapacity<Alloc>( - len + otherLen, sizeof(elem_type)))) { + if (!Alloc::Successful(this->template ExtendCapacity<Alloc>( + len, otherLen, sizeof(elem_type)))) { return nullptr; } copy_type::MoveNonOverlappingRegion(Elements() + len, aArray.Elements(), otherLen, @@ -2140,6 +2153,7 @@ template<class Item, typename ActualAlloc> auto nsTArray_Impl<E, Alloc>::AppendElement(Item&& aItem) -> elem_type* { + // Length() + 1 is guaranteed to not overflow, so EnsureCapacity is OK. if (!ActualAlloc::Successful(this->template EnsureCapacity<ActualAlloc>( Length() + 1, sizeof(elem_type)))) { return nullptr; |