Author: Fangrui Song Date: 2024-10-26T10:31:26-07:00 New Revision: 2fc9c0dda365e578aa807b770bd16bd2316cab1b
URL: https://github.com/llvm/llvm-project/commit/2fc9c0dda365e578aa807b770bd16bd2316cab1b DIFF: https://github.com/llvm/llvm-project/commit/2fc9c0dda365e578aa807b770bd16bd2316cab1b.diff LOG: Revert "[ADT] Teach StringRef to derive from std::string_view (#113752)" This reverts commit a3181b11b5b758cfa852c0d27465f84ab3b079bb. Added: Modified: llvm/include/llvm/ADT/StringRef.h Removed: ################################################################################ diff --git a/llvm/include/llvm/ADT/StringRef.h b/llvm/include/llvm/ADT/StringRef.h index 49b6b8ff52abec..d5f30b88c4c6a2 100644 --- a/llvm/include/llvm/ADT/StringRef.h +++ b/llvm/include/llvm/ADT/StringRef.h @@ -48,9 +48,7 @@ namespace llvm { /// situations where the character data resides in some other buffer, whose /// lifetime extends past that of the StringRef. For this reason, it is not in /// general safe to store a StringRef. - class LLVM_GSL_POINTER StringRef : public std::string_view { - using Base = std::string_view; - + class LLVM_GSL_POINTER StringRef { public: static constexpr size_t npos = ~size_t(0); @@ -62,6 +60,12 @@ namespace llvm { using const_reverse_iterator = std::reverse_iterator<const_iterator>; private: + /// The start of the string, in an external buffer. + const char *Data = nullptr; + + /// The length of the string. + size_t Length = 0; + // Workaround memcmp issue with null pointers (undefined behavior) // by providing a specialized version static int compareMemory(const char *Lhs, const char *Rhs, size_t Length) { @@ -82,25 +86,27 @@ namespace llvm { /// Construct a string ref from a cstring. /*implicit*/ constexpr StringRef(const char *Str) - : Base(Str, Str ? + : Data(Str), Length(Str ? // GCC 7 doesn't have constexpr char_traits. Fall back to __builtin_strlen. #if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE < 8 - __builtin_strlen(Str) + __builtin_strlen(Str) #else - std::char_traits<char>::length(Str) + std::char_traits<char>::length(Str) #endif - : 0) { + : 0) { } /// Construct a string ref from a pointer and length. /*implicit*/ constexpr StringRef(const char *data, size_t length) - : Base(data, length) {} + : Data(data), Length(length) {} /// Construct a string ref from an std::string. - /*implicit*/ StringRef(const std::string &Str) : Base(Str) {} + /*implicit*/ StringRef(const std::string &Str) + : Data(Str.data()), Length(Str.length()) {} /// Construct a string ref from an std::string_view. - /*implicit*/ constexpr StringRef(std::string_view Str) : Base(Str) {} + /*implicit*/ constexpr StringRef(std::string_view Str) + : Data(Str.data()), Length(Str.size()) {} /// @} /// @name Iterators @@ -132,9 +138,16 @@ namespace llvm { /// @name String Operations /// @{ + /// data - Get a pointer to the start of the string (which may not be null + /// terminated). + [[nodiscard]] constexpr const char *data() const { return Data; } + /// empty - Check if the string is empty. [[nodiscard]] constexpr bool empty() const { return size() == 0; } + /// size - Get the string size. + [[nodiscard]] constexpr size_t size() const { return Length; } + /// front - Get the first character in the string. [[nodiscard]] char front() const { assert(!empty()); @@ -235,6 +248,14 @@ namespace llvm { std::enable_if_t<std::is_same<T, std::string>::value, StringRef> & operator=(T &&Str) = delete; + /// @} + /// @name Type Conversions + /// @{ + + constexpr operator std::string_view() const { + return std::string_view(data(), size()); + } + /// @} /// @name String Predicates /// @{ _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
