YQ Connector: support managed ClickHouse

Со стороны dqrun можно обратиться к инстансу коннектора, который работает на streaming стенде, и извлечь данные из облачного CH.

1 files changed, 1006 insertions, 0 deletions

diff --git a/contrib/libs/llvm14/include/llvm/ADT/StringRef.h b/contrib/libs/llvm14/include/llvm/ADT/StringRef.h
new file mode 100644
index 0000000000..87d136fec2
--- /dev/null
+++ b/contrib/libs/llvm14/include/llvm/ADT/StringRef.h
@@ -0,0 +1,1006 @@
+#pragma once
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
+
+//===- StringRef.h - Constant String Reference Wrapper ----------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_ADT_STRINGREF_H
+#define LLVM_ADT_STRINGREF_H
+
+#include "llvm/ADT/DenseMapInfo.h"
+#include "llvm/ADT/STLFunctionalExtras.h"
+#include "llvm/ADT/iterator_range.h"
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstring>
+#include <limits>
+#include <string>
+#if __cplusplus > 201402L
+#include <string_view>
+#endif
+#include <type_traits>
+#include <utility>
+
+// Declare the __builtin_strlen intrinsic for MSVC so it can be used in
+// constexpr context.
+#if defined(_MSC_VER)
+extern "C" size_t __builtin_strlen(const char *);
+#endif
+
+namespace llvm {
+
+  class APInt;
+  class hash_code;
+  template <typename T> class SmallVectorImpl;
+  class StringRef;
+
+  /// Helper functions for StringRef::getAsInteger.
+  bool getAsUnsignedInteger(StringRef Str, unsigned Radix,
+                            unsigned long long &Result);
+
+  bool getAsSignedInteger(StringRef Str, unsigned Radix, long long &Result);
+
+  bool consumeUnsignedInteger(StringRef &Str, unsigned Radix,
+                              unsigned long long &Result);
+  bool consumeSignedInteger(StringRef &Str, unsigned Radix, long long &Result);
+
+  /// StringRef - Represent a constant reference to a string, i.e. a character
+  /// array and a length, which need not be null terminated.
+  ///
+  /// This class does not own the string data, it is expected to be used in
+  /// 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:
+    static constexpr size_t npos = ~size_t(0);
+
+    using iterator = const char *;
+    using const_iterator = const char *;
+    using size_type = size_t;
+
+  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) {
+      if (Length == 0) { return 0; }
+      return ::memcmp(Lhs,Rhs,Length);
+    }
+
+    // Constexpr version of std::strlen.
+    static constexpr size_t strLen(const char *Str) {
+#if __cplusplus > 201402L
+      return std::char_traits<char>::length(Str);
+#elif __has_builtin(__builtin_strlen) || defined(__GNUC__) || \
+    (defined(_MSC_VER) && _MSC_VER >= 1916)
+      return __builtin_strlen(Str);
+#else
+      const char *Begin = Str;
+      while (*Str != '\0')
+        ++Str;
+      return Str - Begin;
+#endif
+    }
+
+  public:
+    /// @name Constructors
+    /// @{
+
+    /// Construct an empty string ref.
+    /*implicit*/ StringRef() = default;
+
+    /// Disable conversion from nullptr.  This prevents things like
+    /// if (S == nullptr)
+    StringRef(std::nullptr_t) = delete;
+
+    /// Construct a string ref from a cstring.
+    /*implicit*/ constexpr StringRef(const char *Str)
+        : Data(Str), Length(Str ? strLen(Str) : 0) {}
+
+    /// Construct a string ref from a pointer and length.
+    /*implicit*/ constexpr StringRef(const char *data, size_t length)
+        : Data(data), Length(length) {}
+
+    /// Construct a string ref from an std::string.
+    /*implicit*/ StringRef(const std::string &Str)
+      : Data(Str.data()), Length(Str.length()) {}
+
+#if __cplusplus > 201402L
+    /// Construct a string ref from an std::string_view.
+    /*implicit*/ constexpr StringRef(std::string_view Str)
+        : Data(Str.data()), Length(Str.size()) {}
+#endif
+
+    /// @}
+    /// @name Iterators
+    /// @{
+
+    iterator begin() const { return Data; }
+
+    iterator end() const { return Data + Length; }
+
+    const unsigned char *bytes_begin() const {
+      return reinterpret_cast<const unsigned char *>(begin());
+    }
+    const unsigned char *bytes_end() const {
+      return reinterpret_cast<const unsigned char *>(end());
+    }
+    iterator_range<const unsigned char *> bytes() const {
+      return make_range(bytes_begin(), bytes_end());
+    }
+
+    /// @}
+    /// @name String Operations
+    /// @{
+
+    /// data - Get a pointer to the start of the string (which may not be null
+    /// terminated).
+    LLVM_NODISCARD
+    const char *data() const { return Data; }
+
+    /// empty - Check if the string is empty.
+    LLVM_NODISCARD
+    constexpr bool empty() const { return Length == 0; }
+
+    /// size - Get the string size.
+    LLVM_NODISCARD
+    constexpr size_t size() const { return Length; }
+
+    /// front - Get the first character in the string.
+    LLVM_NODISCARD
+    char front() const {
+      assert(!empty());
+      return Data[0];
+    }
+
+    /// back - Get the last character in the string.
+    LLVM_NODISCARD
+    char back() const {
+      assert(!empty());
+      return Data[Length-1];
+    }
+
+    // copy - Allocate copy in Allocator and return StringRef to it.
+    template <typename Allocator>
+    LLVM_NODISCARD StringRef copy(Allocator &A) const {
+      // Don't request a length 0 copy from the allocator.
+      if (empty())
+        return StringRef();
+      char *S = A.template Allocate<char>(Length);
+      std::copy(begin(), end(), S);
+      return StringRef(S, Length);
+    }
+
+    /// equals - Check for string equality, this is more efficient than
+    /// compare() when the relative ordering of inequal strings isn't needed.
+    LLVM_NODISCARD
+    bool equals(StringRef RHS) const {
+      return (Length == RHS.Length &&
+              compareMemory(Data, RHS.Data, RHS.Length) == 0);
+    }
+
+    /// Check for string equality, ignoring case.
+    LLVM_NODISCARD
+    bool equals_insensitive(StringRef RHS) const {
+      return Length == RHS.Length && compare_insensitive(RHS) == 0;
+    }
+
+    /// compare - Compare two strings; the result is -1, 0, or 1 if this string
+    /// is lexicographically less than, equal to, or greater than the \p RHS.
+    LLVM_NODISCARD
+    int compare(StringRef RHS) const {
+      // Check the prefix for a mismatch.
+      if (int Res = compareMemory(Data, RHS.Data, std::min(Length, RHS.Length)))
+        return Res < 0 ? -1 : 1;
+
+      // Otherwise the prefixes match, so we only need to check the lengths.
+      if (Length == RHS.Length)
+        return 0;
+      return Length < RHS.Length ? -1 : 1;
+    }
+
+    /// Compare two strings, ignoring case.
+    LLVM_NODISCARD
+    int compare_insensitive(StringRef RHS) const;
+
+    /// compare_numeric - Compare two strings, treating sequences of digits as
+    /// numbers.
+    LLVM_NODISCARD
+    int compare_numeric(StringRef RHS) const;
+
+    /// Determine the edit distance between this string and another
+    /// string.
+    ///
+    /// \param Other the string to compare this string against.
+    ///
+    /// \param AllowReplacements whether to allow character
+    /// replacements (change one character into another) as a single
+    /// operation, rather than as two operations (an insertion and a
+    /// removal).
+    ///
+    /// \param MaxEditDistance If non-zero, the maximum edit distance that
+    /// this routine is allowed to compute. If the edit distance will exceed
+    /// that maximum, returns \c MaxEditDistance+1.
+    ///
+    /// \returns the minimum number of character insertions, removals,
+    /// or (if \p AllowReplacements is \c true) replacements needed to
+    /// transform one of the given strings into the other. If zero,
+    /// the strings are identical.
+    LLVM_NODISCARD
+    unsigned edit_distance(StringRef Other, bool AllowReplacements = true,
+                           unsigned MaxEditDistance = 0) const;
+
+    /// str - Get the contents as an std::string.
+    LLVM_NODISCARD
+    std::string str() const {
+      if (!Data) return std::string();
+      return std::string(Data, Length);
+    }
+
+    /// @}
+    /// @name Operator Overloads
+    /// @{
+
+    LLVM_NODISCARD
+    char operator[](size_t Index) const {
+      assert(Index < Length && "Invalid index!");
+      return Data[Index];
+    }
+
+    /// Disallow accidental assignment from a temporary std::string.
+    ///
+    /// The declaration here is extra complicated so that `stringRef = {}`
+    /// and `stringRef = "abc"` continue to select the move assignment operator.
+    template <typename T>
+    std::enable_if_t<std::is_same<T, std::string>::value, StringRef> &
+    operator=(T &&Str) = delete;
+
+    /// @}
+    /// @name Type Conversions
+    /// @{
+
+    explicit operator std::string() const { return str(); }
+
+#if __cplusplus > 201402L
+    operator std::string_view() const {
+      return std::string_view(data(), size());
+    }
+#endif
+
+    /// @}
+    /// @name String Predicates
+    /// @{
+
+    /// Check if this string starts with the given \p Prefix.
+    LLVM_NODISCARD
+    bool startswith(StringRef Prefix) const {
+      return Length >= Prefix.Length &&
+             compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
+    }
+
+    /// Check if this string starts with the given \p Prefix, ignoring case.
+    LLVM_NODISCARD
+    bool startswith_insensitive(StringRef Prefix) const;
+
+    /// Check if this string ends with the given \p Suffix.
+    LLVM_NODISCARD
+    bool endswith(StringRef Suffix) const {
+      return Length >= Suffix.Length &&
+        compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
+    }
+
+    /// Check if this string ends with the given \p Suffix, ignoring case.
+    LLVM_NODISCARD
+    bool endswith_insensitive(StringRef Suffix) const;
+
+    /// @}
+    /// @name String Searching
+    /// @{
+
+    /// Search for the first character \p C in the string.
+    ///
+    /// \returns The index of the first occurrence of \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find(char C, size_t From = 0) const {
+      size_t FindBegin = std::min(From, Length);
+      if (FindBegin < Length) { // Avoid calling memchr with nullptr.
+        // Just forward to memchr, which is faster than a hand-rolled loop.
+        if (const void *P = ::memchr(Data + FindBegin, C, Length - FindBegin))
+          return static_cast<const char *>(P) - Data;
+      }
+      return npos;
+    }
+
+    /// Search for the first character \p C in the string, ignoring case.
+    ///
+    /// \returns The index of the first occurrence of \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find_insensitive(char C, size_t From = 0) const;
+
+    /// Search for the first character satisfying the predicate \p F
+    ///
+    /// \returns The index of the first character satisfying \p F starting from
+    /// \p From, or npos if not found.
+    LLVM_NODISCARD
+    size_t find_if(function_ref<bool(char)> F, size_t From = 0) const {
+      StringRef S = drop_front(From);
+      while (!S.empty()) {
+        if (F(S.front()))
+          return size() - S.size();
+        S = S.drop_front();
+      }
+      return npos;
+    }
+
+    /// Search for the first character not satisfying the predicate \p F
+    ///
+    /// \returns The index of the first character not satisfying \p F starting
+    /// from \p From, or npos if not found.
+    LLVM_NODISCARD
+    size_t find_if_not(function_ref<bool(char)> F, size_t From = 0) const {
+      return find_if([F](char c) { return !F(c); }, From);
+    }
+
+    /// Search for the first string \p Str in the string.
+    ///
+    /// \returns The index of the first occurrence of \p Str, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find(StringRef Str, size_t From = 0) const;
+
+    /// Search for the first string \p Str in the string, ignoring case.
+    ///
+    /// \returns The index of the first occurrence of \p Str, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find_insensitive(StringRef Str, size_t From = 0) const;
+
+    /// Search for the last character \p C in the string.
+    ///
+    /// \returns The index of the last occurrence of \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t rfind(char C, size_t From = npos) const {
+      From = std::min(From, Length);
+      size_t i = From;
+      while (i != 0) {
+        --i;
+        if (Data[i] == C)
+          return i;
+      }
+      return npos;
+    }
+
+    /// Search for the last character \p C in the string, ignoring case.
+    ///
+    /// \returns The index of the last occurrence of \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t rfind_insensitive(char C, size_t From = npos) const;
+
+    /// Search for the last string \p Str in the string.
+    ///
+    /// \returns The index of the last occurrence of \p Str, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t rfind(StringRef Str) const;
+
+    /// Search for the last string \p Str in the string, ignoring case.
+    ///
+    /// \returns The index of the last occurrence of \p Str, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t rfind_insensitive(StringRef Str) const;
+
+    /// Find the first character in the string that is \p C, or npos if not
+    /// found. Same as find.
+    LLVM_NODISCARD
+    size_t find_first_of(char C, size_t From = 0) const {
+      return find(C, From);
+    }
+
+    /// Find the first character in the string that is in \p Chars, or npos if
+    /// not found.
+    ///
+    /// Complexity: O(size() + Chars.size())
+    LLVM_NODISCARD
+    size_t find_first_of(StringRef Chars, size_t From = 0) const;
+
+    /// Find the first character in the string that is not \p C or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find_first_not_of(char C, size_t From = 0) const;
+
+    /// Find the first character in the string that is not in the string
+    /// \p Chars, or npos if not found.
+    ///
+    /// Complexity: O(size() + Chars.size())
+    LLVM_NODISCARD
+    size_t find_first_not_of(StringRef Chars, size_t From = 0) const;
+
+    /// Find the last character in the string that is \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find_last_of(char C, size_t From = npos) const {
+      return rfind(C, From);
+    }
+
+    /// Find the last character in the string that is in \p C, or npos if not
+    /// found.
+    ///
+    /// Complexity: O(size() + Chars.size())
+    LLVM_NODISCARD
+    size_t find_last_of(StringRef Chars, size_t From = npos) const;
+
+    /// Find the last character in the string that is not \p C, or npos if not
+    /// found.
+    LLVM_NODISCARD
+    size_t find_last_not_of(char C, size_t From = npos) const;
+
+    /// Find the last character in the string that is not in \p Chars, or
+    /// npos if not found.
+    ///
+    /// Complexity: O(size() + Chars.size())
+    LLVM_NODISCARD
+    size_t find_last_not_of(StringRef Chars, size_t From = npos) const;
+
+    /// Return true if the given string is a substring of *this, and false
+    /// otherwise.
+    LLVM_NODISCARD
+    bool contains(StringRef Other) const { return find(Other) != npos; }
+
+    /// Return true if the given character is contained in *this, and false
+    /// otherwise.
+    LLVM_NODISCARD
+    bool contains(char C) const { return find_first_of(C) != npos; }
+
+    /// Return true if the given string is a substring of *this, and false
+    /// otherwise.
+    LLVM_NODISCARD
+    bool contains_insensitive(StringRef Other) const {
+      return find_insensitive(Other) != npos;
+    }
+
+    /// Return true if the given character is contained in *this, and false
+    /// otherwise.
+    LLVM_NODISCARD
+    bool contains_insensitive(char C) const {
+      return find_insensitive(C) != npos;
+    }
+
+    /// @}
+    /// @name Helpful Algorithms
+    /// @{
+
+    /// Return the number of occurrences of \p C in the string.
+    LLVM_NODISCARD
+    size_t count(char C) const {
+      size_t Count = 0;
+      for (size_t i = 0, e = Length; i != e; ++i)
+        if (Data[i] == C)
+          ++Count;
+      return Count;
+    }
+
+    /// Return the number of non-overlapped occurrences of \p Str in
+    /// the string.
+    size_t count(StringRef Str) const;
+
+    /// Parse the current string as an integer of the specified radix.  If
+    /// \p Radix is specified as zero, this does radix autosensing using
+    /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
+    ///
+    /// If the string is invalid or if only a subset of the string is valid,
+    /// this returns true to signify the error.  The string is considered
+    /// erroneous if empty or if it overflows T.
+    template <typename T>
+    std::enable_if_t<std::numeric_limits<T>::is_signed, bool>
+    getAsInteger(unsigned Radix, T &Result) const {
+      long long LLVal;
+      if (getAsSignedInteger(*this, Radix, LLVal) ||
+            static_cast<T>(LLVal) != LLVal)
+        return true;
+      Result = LLVal;
+      return false;
+    }
+
+    template <typename T>
+    std::enable_if_t<!std::numeric_limits<T>::is_signed, bool>
+    getAsInteger(unsigned Radix, T &Result) const {
+      unsigned long long ULLVal;
+      // The additional cast to unsigned long long is required to avoid the
+      // Visual C++ warning C4805: '!=' : unsafe mix of type 'bool' and type
+      // 'unsigned __int64' when instantiating getAsInteger with T = bool.
+      if (getAsUnsignedInteger(*this, Radix, ULLVal) ||
+          static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
+        return true;
+      Result = ULLVal;
+      return false;
+    }
+
+    /// Parse the current string as an integer of the specified radix.  If
+    /// \p Radix is specified as zero, this does radix autosensing using
+    /// extended C rules: 0 is octal, 0x is hex, 0b is binary.
+    ///
+    /// If the string does not begin with a number of the specified radix,
+    /// this returns true to signify the error. The string is considered
+    /// erroneous if empty or if it overflows T.
+    /// The portion of the string representing the discovered numeric value
+    /// is removed from the beginning of the string.
+    template <typename T>
+    std::enable_if_t<std::numeric_limits<T>::is_signed, bool>
+    consumeInteger(unsigned Radix, T &Result) {
+      long long LLVal;
+      if (consumeSignedInteger(*this, Radix, LLVal) ||
+          static_cast<long long>(static_cast<T>(LLVal)) != LLVal)
+        return true;
+      Result = LLVal;
+      return false;
+    }
+
+    template <typename T>
+    std::enable_if_t<!std::numeric_limits<T>::is_signed, bool>
+    consumeInteger(unsigned Radix, T &Result) {
+      unsigned long long ULLVal;
+      if (consumeUnsignedInteger(*this, Radix, ULLVal) ||
+          static_cast<unsigned long long>(static_cast<T>(ULLVal)) != ULLVal)
+        return true;
+      Result = ULLVal;
+      return false;
+    }
+
+    /// Parse the current string as an integer of the specified \p Radix, or of
+    /// an autosensed radix if the \p Radix given is 0.  The current value in
+    /// \p Result is discarded, and the storage is changed to be wide enough to
+    /// store the parsed integer.
+    ///
+    /// \returns true if the string does not solely consist of a valid
+    /// non-empty number in the appropriate base.
+    ///
+    /// APInt::fromString is superficially similar but assumes the
+    /// string is well-formed in the given radix.
+    bool getAsInteger(unsigned Radix, APInt &Result) const;
+
+    /// Parse the current string as an IEEE double-precision floating
+    /// point value.  The string must be a well-formed double.
+    ///
+    /// If \p AllowInexact is false, the function will fail if the string
+    /// cannot be represented exactly.  Otherwise, the function only fails
+    /// in case of an overflow or underflow, or an invalid floating point
+    /// representation.
+    bool getAsDouble(double &Result, bool AllowInexact = true) const;
+
+    /// @}
+    /// @name String Operations
+    /// @{
+
+    // Convert the given ASCII string to lowercase.
+    LLVM_NODISCARD
+    std::string lower() const;
+
+    /// Convert the given ASCII string to uppercase.
+    LLVM_NODISCARD
+    std::string upper() const;
+
+    /// @}
+    /// @name Substring Operations
+    /// @{
+
+    /// Return a reference to the substring from [Start, Start + N).
+    ///
+    /// \param Start The index of the starting character in the substring; if
+    /// the index is npos or greater than the length of the string then the
+    /// empty substring will be returned.
+    ///
+    /// \param N The number of characters to included in the substring. If N
+    /// exceeds the number of characters remaining in the string, the string
+    /// suffix (starting with \p Start) will be returned.
+    LLVM_NODISCARD
+    StringRef substr(size_t Start, size_t N = npos) const {
+      Start = std::min(Start, Length);
+      return StringRef(Data + Start, std::min(N, Length - Start));
+    }
+
+    /// Return a StringRef equal to 'this' but with only the first \p N
+    /// elements remaining.  If \p N is greater than the length of the
+    /// string, the entire string is returned.
+    LLVM_NODISCARD
+    StringRef take_front(size_t N = 1) const {
+      if (N >= size())
+        return *this;
+      return drop_back(size() - N);
+    }
+
+    /// Return a StringRef equal to 'this' but with only the last \p N
+    /// elements remaining.  If \p N is greater than the length of the
+    /// string, the entire string is returned.
+    LLVM_NODISCARD
+    StringRef take_back(size_t N = 1) const {
+      if (N >= size())
+        return *this;
+      return drop_front(size() - N);
+    }
+
+    /// Return the longest prefix of 'this' such that every character
+    /// in the prefix satisfies the given predicate.
+    LLVM_NODISCARD
+    StringRef take_while(function_ref<bool(char)> F) const {
+      return substr(0, find_if_not(F));
+    }
+
+    /// Return the longest prefix of 'this' such that no character in
+    /// the prefix satisfies the given predicate.
+    LLVM_NODISCARD
+    StringRef take_until(function_ref<bool(char)> F) const {
+      return substr(0, find_if(F));
+    }
+
+    /// Return a StringRef equal to 'this' but with the first \p N elements
+    /// dropped.
+    LLVM_NODISCARD
+    StringRef drop_front(size_t N = 1) const {
+      assert(size() >= N && "Dropping more elements than exist");
+      return substr(N);
+    }
+
+    /// Return a StringRef equal to 'this' but with the last \p N elements
+    /// dropped.
+    LLVM_NODISCARD
+    StringRef drop_back(size_t N = 1) const {
+      assert(size() >= N && "Dropping more elements than exist");
+      return substr(0, size()-N);
+    }
+
+    /// Return a StringRef equal to 'this', but with all characters satisfying
+    /// the given predicate dropped from the beginning of the string.
+    LLVM_NODISCARD
+    StringRef drop_while(function_ref<bool(char)> F) const {
+      return substr(find_if_not(F));
+    }
+
+    /// Return a StringRef equal to 'this', but with all characters not
+    /// satisfying the given predicate dropped from the beginning of the string.
+    LLVM_NODISCARD
+    StringRef drop_until(function_ref<bool(char)> F) const {
+      return substr(find_if(F));
+    }
+
+    /// Returns true if this StringRef has the given prefix and removes that
+    /// prefix.
+    bool consume_front(StringRef Prefix) {
+      if (!startswith(Prefix))
+        return false;
+
+      *this = drop_front(Prefix.size());
+      return true;
+    }
+
+    /// Returns true if this StringRef has the given prefix, ignoring case,
+    /// and removes that prefix.
+    bool consume_front_insensitive(StringRef Prefix) {
+      if (!startswith_insensitive(Prefix))
+        return false;
+
+      *this = drop_front(Prefix.size());
+      return true;
+    }
+
+    /// Returns true if this StringRef has the given suffix and removes that
+    /// suffix.
+    bool consume_back(StringRef Suffix) {
+      if (!endswith(Suffix))
+        return false;
+
+      *this = drop_back(Suffix.size());
+      return true;
+    }
+
+    /// Returns true if this StringRef has the given suffix, ignoring case,
+    /// and removes that suffix.
+    bool consume_back_insensitive(StringRef Suffix) {
+      if (!endswith_insensitive(Suffix))
+        return false;
+
+      *this = drop_back(Suffix.size());
+      return true;
+    }
+
+    /// Return a reference to the substring from [Start, End).
+    ///
+    /// \param Start The index of the starting character in the substring; if
+    /// the index is npos or greater than the length of the string then the
+    /// empty substring will be returned.
+    ///
+    /// \param End The index following the last character to include in the
+    /// substring. If this is npos or exceeds the number of characters
+    /// remaining in the string, the string suffix (starting with \p Start)
+    /// will be returned. If this is less than \p Start, an empty string will
+    /// be returned.
+    LLVM_NODISCARD
+    StringRef slice(size_t Start, size_t End) const {
+      Start = std::min(Start, Length);
+      End = std::min(std::max(Start, End), Length);
+      return StringRef(Data + Start, End - Start);
+    }
+
+    /// Split into two substrings around the first occurrence of a separator
+    /// character.
+    ///
+    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
+    /// such that (*this == LHS + Separator + RHS) is true and RHS is
+    /// maximal. If \p Separator is not in the string, then the result is a
+    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+    ///
+    /// \param Separator The character to split on.
+    /// \returns The split substrings.
+    LLVM_NODISCARD
+    std::pair<StringRef, StringRef> split(char Separator) const {
+      return split(StringRef(&Separator, 1));
+    }
+
+    /// Split into two substrings around the first occurrence of a separator
+    /// string.
+    ///
+    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
+    /// such that (*this == LHS + Separator + RHS) is true and RHS is
+    /// maximal. If \p Separator is not in the string, then the result is a
+    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+    ///
+    /// \param Separator - The string to split on.
+    /// \return - The split substrings.
+    LLVM_NODISCARD
+    std::pair<StringRef, StringRef> split(StringRef Separator) const {
+      size_t Idx = find(Separator);
+      if (Idx == npos)
+        return std::make_pair(*this, StringRef());
+      return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
+    }
+
+    /// Split into two substrings around the last occurrence of a separator
+    /// string.
+    ///
+    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
+    /// such that (*this == LHS + Separator + RHS) is true and RHS is
+    /// minimal. If \p Separator is not in the string, then the result is a
+    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+    ///
+    /// \param Separator - The string to split on.
+    /// \return - The split substrings.
+    LLVM_NODISCARD
+    std::pair<StringRef, StringRef> rsplit(StringRef Separator) const {
+      size_t Idx = rfind(Separator);
+      if (Idx == npos)
+        return std::make_pair(*this, StringRef());
+      return std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
+    }
+
+    /// Split into substrings around the occurrences of a separator string.
+    ///
+    /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
+    /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
+    /// elements are added to A.
+    /// If \p KeepEmpty is false, empty strings are not added to \p A. They
+    /// still count when considering \p MaxSplit
+    /// An useful invariant is that
+    /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
+    ///
+    /// \param A - Where to put the substrings.
+    /// \param Separator - The string to split on.
+    /// \param MaxSplit - The maximum number of times the string is split.
+    /// \param KeepEmpty - True if empty substring should be added.
+    void split(SmallVectorImpl<StringRef> &A,
+               StringRef Separator, int MaxSplit = -1,
+               bool KeepEmpty = true) const;
+
+    /// Split into substrings around the occurrences of a separator character.
+    ///
+    /// Each substring is stored in \p A. If \p MaxSplit is >= 0, at most
+    /// \p MaxSplit splits are done and consequently <= \p MaxSplit + 1
+    /// elements are added to A.
+    /// If \p KeepEmpty is false, empty strings are not added to \p A. They
+    /// still count when considering \p MaxSplit
+    /// An useful invariant is that
+    /// Separator.join(A) == *this if MaxSplit == -1 and KeepEmpty == true
+    ///
+    /// \param A - Where to put the substrings.
+    /// \param Separator - The string to split on.
+    /// \param MaxSplit - The maximum number of times the string is split.
+    /// \param KeepEmpty - True if empty substring should be added.
+    void split(SmallVectorImpl<StringRef> &A, char Separator, int MaxSplit = -1,
+               bool KeepEmpty = true) const;
+
+    /// Split into two substrings around the last occurrence of a separator
+    /// character.
+    ///
+    /// If \p Separator is in the string, then the result is a pair (LHS, RHS)
+    /// such that (*this == LHS + Separator + RHS) is true and RHS is
+    /// minimal. If \p Separator is not in the string, then the result is a
+    /// pair (LHS, RHS) where (*this == LHS) and (RHS == "").
+    ///
+    /// \param Separator - The character to split on.
+    /// \return - The split substrings.
+    LLVM_NODISCARD
+    std::pair<StringRef, StringRef> rsplit(char Separator) const {
+      return rsplit(StringRef(&Separator, 1));
+    }
+
+    /// Return string with consecutive \p Char characters starting from the
+    /// the left removed.
+    LLVM_NODISCARD
+    StringRef ltrim(char Char) const {
+      return drop_front(std::min(Length, find_first_not_of(Char)));
+    }
+
+    /// Return string with consecutive characters in \p Chars starting from
+    /// the left removed.
+    LLVM_NODISCARD
+    StringRef ltrim(StringRef Chars = " \t\n\v\f\r") const {
+      return drop_front(std::min(Length, find_first_not_of(Chars)));
+    }
+
+    /// Return string with consecutive \p Char characters starting from the
+    /// right removed.
+    LLVM_NODISCARD
+    StringRef rtrim(char Char) const {
+      return drop_back(Length - std::min(Length, find_last_not_of(Char) + 1));
+    }
+
+    /// Return string with consecutive characters in \p Chars starting from
+    /// the right removed.
+    LLVM_NODISCARD
+    StringRef rtrim(StringRef Chars = " \t\n\v\f\r") const {
+      return drop_back(Length - std::min(Length, find_last_not_of(Chars) + 1));
+    }
+
+    /// Return string with consecutive \p Char characters starting from the
+    /// left and right removed.
+    LLVM_NODISCARD
+    StringRef trim(char Char) const {
+      return ltrim(Char).rtrim(Char);
+    }
+
+    /// Return string with consecutive characters in \p Chars starting from
+    /// the left and right removed.
+    LLVM_NODISCARD
+    StringRef trim(StringRef Chars = " \t\n\v\f\r") const {
+      return ltrim(Chars).rtrim(Chars);
+    }
+
+    /// Detect the line ending style of the string.
+    ///
+    /// If the string contains a line ending, return the line ending character
+    /// sequence that is detected. Otherwise return '\n' for unix line endings.
+    ///
+    /// \return - The line ending character sequence.
+    LLVM_NODISCARD
+    StringRef detectEOL() const {
+      size_t Pos = find('\r');
+      if (Pos == npos) {
+        // If there is no carriage return, assume unix
+        return "\n";
+      }
+      if (Pos + 1 < Length && Data[Pos + 1] == '\n')
+        return "\r\n"; // Windows
+      if (Pos > 0 && Data[Pos - 1] == '\n')
+        return "\n\r"; // You monster!
+      return "\r";     // Classic Mac
+    }
+    /// @}
+  };
+
+  /// A wrapper around a string literal that serves as a proxy for constructing
+  /// global tables of StringRefs with the length computed at compile time.
+  /// In order to avoid the invocation of a global constructor, StringLiteral
+  /// should *only* be used in a constexpr context, as such:
+  ///
+  /// constexpr StringLiteral S("test");
+  ///
+  class StringLiteral : public StringRef {
+  private:
+    constexpr StringLiteral(const char *Str, size_t N) : StringRef(Str, N) {
+    }
+
+  public:
+    template <size_t N>
+    constexpr StringLiteral(const char (&Str)[N])
+#if defined(__clang__) && __has_attribute(enable_if)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wgcc-compat"
+        __attribute((enable_if(__builtin_strlen(Str) == N - 1,
+                               "invalid string literal")))
+#pragma clang diagnostic pop
+#endif
+        : StringRef(Str, N - 1) {
+    }
+
+    // Explicit construction for strings like "foo\0bar".
+    template <size_t N>
+    static constexpr StringLiteral withInnerNUL(const char (&Str)[N]) {
+      return StringLiteral(Str, N - 1);
+    }
+  };
+
+  /// @name StringRef Comparison Operators
+  /// @{
+
+  inline bool operator==(StringRef LHS, StringRef RHS) {
+    return LHS.equals(RHS);
+  }
+
+  inline bool operator!=(StringRef LHS, StringRef RHS) { return !(LHS == RHS); }
+
+  inline bool operator<(StringRef LHS, StringRef RHS) {
+    return LHS.compare(RHS) == -1;
+  }
+
+  inline bool operator<=(StringRef LHS, StringRef RHS) {
+    return LHS.compare(RHS) != 1;
+  }
+
+  inline bool operator>(StringRef LHS, StringRef RHS) {
+    return LHS.compare(RHS) == 1;
+  }
+
+  inline bool operator>=(StringRef LHS, StringRef RHS) {
+    return LHS.compare(RHS) != -1;
+  }
+
+  inline std::string &operator+=(std::string &buffer, StringRef string) {
+    return buffer.append(string.data(), string.size());
+  }
+
+  /// @}
+
+  /// Compute a hash_code for a StringRef.
+  LLVM_NODISCARD
+  hash_code hash_value(StringRef S);
+
+  // Provide DenseMapInfo for StringRefs.
+  template <> struct DenseMapInfo<StringRef, void> {
+    static inline StringRef getEmptyKey() {
+      return StringRef(
+          reinterpret_cast<const char *>(~static_cast<uintptr_t>(0)), 0);
+    }
+
+    static inline StringRef getTombstoneKey() {
+      return StringRef(
+          reinterpret_cast<const char *>(~static_cast<uintptr_t>(1)), 0);
+    }
+
+    static unsigned getHashValue(StringRef Val);
+
+    static bool isEqual(StringRef LHS, StringRef RHS) {
+      if (RHS.data() == getEmptyKey().data())
+        return LHS.data() == getEmptyKey().data();
+      if (RHS.data() == getTombstoneKey().data())
+        return LHS.data() == getTombstoneKey().data();
+      return LHS == RHS;
+    }
+  };
+
+} // end namespace llvm
+
+#endif // LLVM_ADT_STRINGREF_H
+
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif