X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FADT%2FArrayRef.h;h=1e35d62792195b0d0b73b04ac405ce7cb68b35f1;hb=5d37976090df34f003e5128e39593b763be0ca71;hp=f41a99403188464bb721c4c2de5a67d8151b13d4;hpb=1752e45de9914cb52d748c1052ecd2f1414bced4;p=oota-llvm.git diff --git a/include/llvm/ADT/ArrayRef.h b/include/llvm/ADT/ArrayRef.h index f41a9940318..1e35d627921 100644 --- a/include/llvm/ADT/ArrayRef.h +++ b/include/llvm/ADT/ArrayRef.h @@ -14,8 +14,7 @@ #include namespace llvm { - class APInt; - + /// ArrayRef - Represent a constant reference to an array (0 or more elements /// consecutively in memory), i.e. a start pointer and a length. It allows /// various APIs to take consecutive elements easily and conveniently. @@ -33,73 +32,78 @@ namespace llvm { typedef const T *iterator; typedef const T *const_iterator; typedef size_t size_type; - + private: /// The start of the array, in an external buffer. const T *Data; - + /// The number of elements. size_type Length; - + public: /// @name Constructors /// @{ - + /// Construct an empty ArrayRef. /*implicit*/ ArrayRef() : Data(0), Length(0) {} - + /// Construct an ArrayRef from a single element. /*implicit*/ ArrayRef(const T &OneElt) : Data(&OneElt), Length(1) {} - + /// Construct an ArrayRef from a pointer and length. /*implicit*/ ArrayRef(const T *data, size_t length) : Data(data), Length(length) {} - + /// Construct an ArrayRef from a range. ArrayRef(const T *begin, const T *end) : Data(begin), Length(end - begin) {} - - /// Construct an ArrayRef from a SmallVector. - /*implicit*/ ArrayRef(const SmallVectorImpl &Vec) - : Data(Vec.data()), Length(Vec.size()) {} + + /// Construct an ArrayRef from a SmallVector. This is templated in order to + /// avoid instantiating SmallVectorTemplateCommon whenever we + /// copy-construct an ArrayRef. + template + /*implicit*/ ArrayRef(const SmallVectorTemplateCommon &Vec) + : Data(Vec.data()), Length(Vec.size()) { + } /// Construct an ArrayRef from a std::vector. - /*implicit*/ ArrayRef(const std::vector &Vec) + template + /*implicit*/ ArrayRef(const std::vector &Vec) : Data(Vec.empty() ? (T*)0 : &Vec[0]), Length(Vec.size()) {} - + /// Construct an ArrayRef from a C array. template /*implicit*/ ArrayRef(const T (&Arr)[N]) : Data(Arr), Length(N) {} - + /// @} /// @name Simple Operations /// @{ iterator begin() const { return Data; } iterator end() const { return Data + Length; } - + /// empty - Check if the array is empty. bool empty() const { return Length == 0; } - + const T *data() const { return Data; } - + /// size - Get the array size. size_t size() const { return Length; } - + /// front - Get the first element. const T &front() const { assert(!empty()); return Data[0]; } - + /// back - Get the last element. const T &back() const { assert(!empty()); return Data[Length-1]; } - + /// equals - Check for element-wise equality. bool equals(ArrayRef RHS) const { if (Length != RHS.Length) @@ -122,7 +126,7 @@ namespace llvm { assert(N+M <= size() && "Invalid specifier"); return ArrayRef(data()+N, M); } - + /// @} /// @name Operator Overloads /// @{ @@ -130,22 +134,104 @@ namespace llvm { assert(Index < Length && "Invalid index!"); return Data[Index]; } - + /// @} /// @name Expensive Operations /// @{ std::vector vec() const { return std::vector(Data, Data+Length); } - + /// @} /// @name Conversion operators /// @{ operator std::vector() const { return std::vector(Data, Data+Length); } + + /// @} + }; + + /// MutableArrayRef - Represent a mutable reference to an array (0 or more + /// elements consecutively in memory), i.e. a start pointer and a length. It + /// allows various APIs to take and modify consecutive elements easily and + /// conveniently. + /// + /// This class does not own the underlying data, it is expected to be used in + /// situations where the data resides in some other buffer, whose lifetime + /// extends past that of the MutableArrayRef. For this reason, it is not in + /// general safe to store a MutableArrayRef. + /// + /// This is intended to be trivially copyable, so it should be passed by + /// value. + template + class MutableArrayRef : public ArrayRef { + public: + typedef T *iterator; + + /// Construct an empty ArrayRef. + /*implicit*/ MutableArrayRef() : ArrayRef() {} + + /// Construct an MutableArrayRef from a single element. + /*implicit*/ MutableArrayRef(T &OneElt) : ArrayRef(OneElt) {} + + /// Construct an MutableArrayRef from a pointer and length. + /*implicit*/ MutableArrayRef(T *data, size_t length) + : ArrayRef(data, length) {} + + /// Construct an MutableArrayRef from a range. + MutableArrayRef(T *begin, T *end) : ArrayRef(begin, end) {} + + /// Construct an MutableArrayRef from a SmallVector. + /*implicit*/ MutableArrayRef(SmallVectorImpl &Vec) + : ArrayRef(Vec) {} + + /// Construct a MutableArrayRef from a std::vector. + /*implicit*/ MutableArrayRef(std::vector &Vec) + : ArrayRef(Vec) {} + + /// Construct an MutableArrayRef from a C array. + template + /*implicit*/ MutableArrayRef(T (&Arr)[N]) + : ArrayRef(Arr) {} + + T *data() const { return const_cast(ArrayRef::data()); } + + iterator begin() const { return data(); } + iterator end() const { return data() + this->size(); } + + /// front - Get the first element. + T &front() const { + assert(!this->empty()); + return data()[0]; + } + + /// back - Get the last element. + T &back() const { + assert(!this->empty()); + return data()[this->size()-1]; + } + + /// slice(n) - Chop off the first N elements of the array. + MutableArrayRef slice(unsigned N) const { + assert(N <= this->size() && "Invalid specifier"); + return MutableArrayRef(data()+N, this->size()-N); + } + + /// slice(n, m) - Chop off the first N elements of the array, and keep M + /// elements in the array. + MutableArrayRef slice(unsigned N, unsigned M) const { + assert(N+M <= this->size() && "Invalid specifier"); + return MutableArrayRef(data()+N, M); + } /// @} + /// @name Operator Overloads + /// @{ + T &operator[](size_t Index) const { + assert(Index < this->size() && "Invalid index!"); + return data()[Index]; + } }; /// @name ArrayRef Convenience constructors @@ -215,5 +301,5 @@ namespace llvm { static const bool value = true; }; } - + #endif