diff --git a/include/llvm/ADT/ArrayRef.h b/include/llvm/ADT/ArrayRef.h index 0fff505d8d0..44400d591da 100644 --- a/include/llvm/ADT/ArrayRef.h +++ b/include/llvm/ADT/ArrayRef.h @@ -11,6 +11,7 @@ #define LLVM_ADT_ARRAYREF_H #include "llvm/ADT/None.h" +#include "llvm/ADT/STLExtras.h" #include "llvm/ADT/SmallVector.h" #include <vector> @@ -43,6 +44,19 @@ namespace llvm { /// The number of elements. size_type Length; + /// \brief A dummy "optional" type that is only created by implicit + /// conversion from a reference to T. + /// + /// This type must *only* be used in a function argument or as a copy of + /// a function argument, as otherwise it will hold a pointer to a temporary + /// past that temporaries' lifetime. + struct TRefOrNothing { + const T *TPtr; + + TRefOrNothing() : TPtr(nullptr) {} + TRefOrNothing(const T &TRef) : TPtr(&TRef) {} + }; + public: /// @name Constructors /// @{ @@ -175,6 +189,47 @@ namespace llvm { return std::vector<T>(Data, Data+Length); } + /// @} + /// @{ + /// @name Convenience methods + + /// @brief Predicate for testing that the array equals the exact sequence of + /// arguments. + /// + /// Will return false if the size is not equal to the exact number of + /// arguments given or if the array elements don't equal the argument + /// elements in order. Currently supports up to 16 arguments, but can + /// easily be extended. + bool equals(TRefOrNothing Arg0 = TRefOrNothing(), + TRefOrNothing Arg1 = TRefOrNothing(), + TRefOrNothing Arg2 = TRefOrNothing(), + TRefOrNothing Arg3 = TRefOrNothing(), + TRefOrNothing Arg4 = TRefOrNothing(), + TRefOrNothing Arg5 = TRefOrNothing(), + TRefOrNothing Arg6 = TRefOrNothing(), + TRefOrNothing Arg7 = TRefOrNothing(), + TRefOrNothing Arg8 = TRefOrNothing(), + TRefOrNothing Arg9 = TRefOrNothing(), + TRefOrNothing Arg10 = TRefOrNothing(), + TRefOrNothing Arg11 = TRefOrNothing(), + TRefOrNothing Arg12 = TRefOrNothing(), + TRefOrNothing Arg13 = TRefOrNothing(), + TRefOrNothing Arg14 = TRefOrNothing(), + TRefOrNothing Arg15 = TRefOrNothing()) { + TRefOrNothing Args[] = {Arg0, Arg1, Arg2, Arg3, Arg4, Arg5, + Arg6, Arg7, Arg8, Arg9, Arg10, Arg11, + Arg12, Arg13, Arg14, Arg15}; + if (size() > array_lengthof(Args)) + return false; + + for (unsigned i = 0, e = size(); i != e; ++i) + if (Args[i].TPtr == nullptr || (*this)[i] != *Args[i].TPtr) + return false; + + // Either the size is exactly as many args, or the next arg must be null. + return size() == array_lengthof(Args) || Args[size()].TPtr == nullptr; + } + /// @} }; diff --git a/unittests/ADT/ArrayRefTest.cpp b/unittests/ADT/ArrayRefTest.cpp index 293afc6ea37..83a012d0cb1 100644 --- a/unittests/ADT/ArrayRefTest.cpp +++ b/unittests/ADT/ArrayRefTest.cpp @@ -36,5 +36,27 @@ TEST(ArrayRefTest, DropBack) { EXPECT_TRUE(AR1.drop_back().equals(AR2)); } +TEST(ArrayRefTest, Equals) { + static const int A1[] = {1, 2, 3, 4, 5, 6, 7, 8}; + ArrayRef<int> AR1(A1); + EXPECT_TRUE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 8)); + EXPECT_FALSE(AR1.equals(8, 1, 2, 4, 5, 6, 6, 7)); + EXPECT_FALSE(AR1.equals(2, 4, 5, 6, 6, 7, 8, 1)); + EXPECT_FALSE(AR1.equals(0, 1, 2, 4, 5, 6, 6, 7)); + EXPECT_FALSE(AR1.equals(1, 2, 42, 4, 5, 6, 7, 8)); + EXPECT_FALSE(AR1.equals(42, 2, 3, 4, 5, 6, 7, 8)); + EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 42)); + EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7)); + EXPECT_FALSE(AR1.equals(1, 2, 3, 4, 5, 6, 7, 8, 9)); + + ArrayRef<int> AR1a = AR1.drop_back(); + EXPECT_TRUE(AR1a.equals(1, 2, 3, 4, 5, 6, 7)); + EXPECT_FALSE(AR1a.equals(1, 2, 3, 4, 5, 6, 7, 8)); + + ArrayRef<int> AR1b = AR1a.slice(2, 4); + EXPECT_TRUE(AR1b.equals(3, 4, 5, 6)); + EXPECT_FALSE(AR1b.equals(2, 3, 4, 5, 6)); + EXPECT_FALSE(AR1b.equals(3, 4, 5, 6, 7)); +} } // end anonymous namespace