#ifndef LLVM_ADT_STRINGREF_H
#define LLVM_ADT_STRINGREF_H
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
#include <cassert>
#include <cstring>
-#include <utility>
+#include <limits>
#include <string>
+#include <utility>
namespace llvm {
- template<typename T>
+ template <typename T>
class SmallVectorImpl;
class APInt;
+ class hash_code;
+ 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);
/// StringRef - Represent a constant reference to a string, i.e. a character
/// array and a length, which need not be null terminated.
/// The length of the string.
size_t Length;
- // Workaround PR5482: nearly all gcc 4.x miscompile StringRef and std::min()
- // Changing the arg of min to be an integer, instead of a reference to an
- // integer works around this bug.
- static size_t min(size_t a, size_t b) { return a < b ? a : b; }
- static size_t max(size_t a, size_t b) { return a > b ? a : b; }
+ // Workaround memcmp issue with null pointers (undefined behavior)
+ // by providing a specialized version
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
+ static int compareMemory(const char *Lhs, const char *Rhs, size_t Length) {
+ if (Length == 0) { return 0; }
+ return ::memcmp(Lhs,Rhs,Length);
+ }
public:
/// @name Constructors
/// @{
/// Construct an empty string ref.
- /*implicit*/ StringRef() : Data(0), Length(0) {}
+ /*implicit*/ StringRef() : Data(nullptr), Length(0) {}
/// Construct a string ref from a cstring.
/*implicit*/ StringRef(const char *Str)
- : Data(Str), Length(::strlen(Str)) {}
+ : Data(Str) {
+ assert(Str && "StringRef cannot be built from a NULL argument");
+ Length = ::strlen(Str); // invoking strlen(NULL) is undefined behavior
+ }
/// Construct a string ref from a pointer and length.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
/*implicit*/ StringRef(const char *data, size_t length)
- : Data(data), Length(length) {}
+ : Data(data), Length(length) {
+ assert((data || length == 0) &&
+ "StringRef cannot be built from a NULL argument with non-null length");
+ }
/// Construct a string ref from an std::string.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
/*implicit*/ StringRef(const std::string &Str)
: Data(Str.data()), Length(Str.length()) {}
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());
+ }
+
/// @}
/// @name String Operations
/// @{
/// data - Get a pointer to the start of the string (which may not be null
/// terminated).
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
const char *data() const { return Data; }
/// empty - Check if the string is empty.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
bool empty() const { return Length == 0; }
/// size - Get the string size.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
size_t size() const { return Length; }
/// front - Get the first character in the string.
return Data[Length-1];
}
+ // copy - Allocate copy in Allocator and return StringRef to it.
+ template <typename Allocator> StringRef copy(Allocator &A) const {
+ 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_ATTRIBUTE_ALWAYS_INLINE
bool equals(StringRef RHS) const {
return (Length == RHS.Length &&
- memcmp(Data, RHS.Data, RHS.Length) == 0);
+ compareMemory(Data, RHS.Data, RHS.Length) == 0);
}
/// equals_lower - Check for string equality, ignoring case.
}
/// compare - Compare two strings; the result is -1, 0, or 1 if this string
- /// is lexicographically less than, equal to, or greater than the \arg RHS.
+ /// is lexicographically less than, equal to, or greater than the \p RHS.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
int compare(StringRef RHS) const {
// Check the prefix for a mismatch.
- if (int Res = memcmp(Data, RHS.Data, min(Length, RHS.Length)))
+ 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.
/// compare_lower - Compare two strings, ignoring case.
int compare_lower(StringRef RHS) const;
- /// \brief Determine the edit distance between this string and another
+ /// compare_numeric - Compare two strings, treating sequences of digits as
+ /// numbers.
+ int compare_numeric(StringRef RHS) const;
+
+ /// \brief Determine the edit distance between this string and another
/// string.
///
/// \param Other the string to compare this string against.
/// 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.
- unsigned edit_distance(StringRef Other, bool AllowReplacements = true);
+ unsigned edit_distance(StringRef Other, bool AllowReplacements = true,
+ unsigned MaxEditDistance = 0) const;
/// str - Get the contents as an std::string.
- std::string str() const { return std::string(Data, Length); }
+ std::string str() const {
+ if (!Data) return std::string();
+ return std::string(Data, Length);
+ }
/// @}
/// @name Operator Overloads
/// @name String Predicates
/// @{
- /// startswith - Check if this string starts with the given \arg Prefix.
+ /// Check if this string starts with the given \p Prefix.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
bool startswith(StringRef Prefix) const {
return Length >= Prefix.Length &&
- memcmp(Data, Prefix.Data, Prefix.Length) == 0;
+ compareMemory(Data, Prefix.Data, Prefix.Length) == 0;
}
- /// endswith - Check if this string ends with the given \arg Suffix.
+ /// Check if this string starts with the given \p Prefix, ignoring case.
+ bool startswith_lower(StringRef Prefix) const;
+
+ /// Check if this string ends with the given \p Suffix.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
bool endswith(StringRef Suffix) const {
return Length >= Suffix.Length &&
- memcmp(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
+ compareMemory(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0;
}
+ /// Check if this string ends with the given \p Suffix, ignoring case.
+ bool endswith_lower(StringRef Suffix) const;
+
/// @}
/// @name String Searching
/// @{
- /// find - Search for the first character \arg C in the string.
+ /// Search for the first character \p C in the string.
///
- /// \return - The index of the first occurrence of \arg C, or npos if not
+ /// \returns The index of the first occurrence of \p C, or npos if not
/// found.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
size_t find(char C, size_t From = 0) const {
- for (size_t i = min(From, Length), e = Length; i != e; ++i)
- if (Data[i] == C)
- return i;
+ 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;
}
- /// find - Search for the first string \arg Str in the string.
+ /// Search for the first string \p Str in the string.
///
- /// \return - The index of the first occurrence of \arg Str, or npos if not
+ /// \returns The index of the first occurrence of \p Str, or npos if not
/// found.
size_t find(StringRef Str, size_t From = 0) const;
- /// rfind - Search for the last character \arg C in the string.
+ /// Search for the last character \p C in the string.
///
- /// \return - The index of the last occurrence of \arg C, or npos if not
+ /// \returns The index of the last occurrence of \p C, or npos if not
/// found.
size_t rfind(char C, size_t From = npos) const {
- From = min(From, Length);
+ From = std::min(From, Length);
size_t i = From;
while (i != 0) {
--i;
return npos;
}
- /// rfind - Search for the last string \arg Str in the string.
+ /// Search for the last string \p Str in the string.
///
- /// \return - The index of the last occurrence of \arg Str, or npos if not
+ /// \returns The index of the last occurrence of \p Str, or npos if not
/// found.
size_t rfind(StringRef Str) const;
- /// find_first_of - Find the first character in the string that is \arg C,
- /// or npos if not found. Same as find.
- size_type find_first_of(char C, size_t = 0) const { return find(C); }
+ /// Find the first character in the string that is \p C, or npos if not
+ /// found. Same as find.
+ 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())
+ 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.
+ 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())
+ 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.
+ size_t find_last_of(char C, size_t From = npos) const {
+ return rfind(C, From);
+ }
- /// find_first_of - Find the first character in the string that is in \arg
- /// Chars, or npos if not found.
+ /// Find the last character in the string that is in \p C, or npos if not
+ /// found.
///
- /// Note: O(size() * Chars.size())
- size_type find_first_of(StringRef Chars, size_t From = 0) const;
+ /// Complexity: O(size() + Chars.size())
+ size_t find_last_of(StringRef Chars, size_t From = npos) const;
- /// find_first_not_of - Find the first character in the string that is not
- /// \arg C or npos if not found.
- size_type find_first_not_of(char C, size_t From = 0) const;
+ /// Find the last character in the string that is not \p C, or npos if not
+ /// found.
+ size_t find_last_not_of(char C, size_t From = npos) const;
- /// find_first_not_of - Find the first character in the string that is not
- /// in the string \arg Chars, or npos if not found.
+ /// Find the last character in the string that is not in \p Chars, or
+ /// npos if not found.
///
- /// Note: O(size() * Chars.size())
- size_type find_first_not_of(StringRef Chars, size_t From = 0) const;
+ /// Complexity: O(size() + Chars.size())
+ size_t find_last_not_of(StringRef Chars, size_t From = npos) const;
/// @}
/// @name Helpful Algorithms
/// @{
- /// count - Return the number of occurrences of \arg C in the string.
+ /// Return the number of occurrences of \p C in the string.
size_t count(char C) const {
size_t Count = 0;
for (size_t i = 0, e = Length; i != e; ++i)
return Count;
}
- /// count - Return the number of non-overlapped occurrences of \arg Str in
+ /// Return the number of non-overlapped occurrences of \p Str in
/// the string.
size_t count(StringRef Str) const;
- /// getAsInteger - Parse the current string as an integer of the specified
- /// radix. If Radix is specified as zero, this does radix autosensing using
+ /// 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.
- ///
- bool getAsInteger(unsigned Radix, long long &Result) const;
- bool getAsInteger(unsigned Radix, unsigned long long &Result) const;
- bool getAsInteger(unsigned Radix, int &Result) const;
- bool getAsInteger(unsigned Radix, unsigned &Result) const;
-
- // TODO: Provide overloads for int/unsigned that check for overflow.
-
- /// getAsInteger - Parse the current string as an integer of the
- /// specified radix, or of an autosensed radix if the radix given
- /// is 0. The current value in Result is discarded, and the
- /// storage is changed to be wide enough to store the parsed
- /// integer.
+ /// erroneous if empty or if it overflows T.
+ template <typename T>
+ typename std::enable_if<std::numeric_limits<T>::is_signed, bool>::type
+ 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>
+ typename std::enable_if<!std::numeric_limits<T>::is_signed, bool>::type
+ 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 \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
+ /// \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;
+ /// @}
+ /// @name String Operations
+ /// @{
+
+ // Convert the given ASCII string to lowercase.
+ std::string lower() const;
+
+ /// Convert the given ASCII string to uppercase.
+ std::string upper() const;
+
/// @}
/// @name Substring Operations
/// @{
- /// substr - Return a reference to the substring from [Start, Start + N).
+ /// Return a reference to the substring from [Start, Start + N).
///
- /// \param Start - The index of the starting character in the substring; if
+ /// \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
+ /// \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 \arg Start) will be returned.
+ /// suffix (starting with \p Start) will be returned.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
StringRef substr(size_t Start, size_t N = npos) const {
- Start = min(Start, Length);
- return StringRef(Data + Start, min(N, Length - Start));
+ Start = std::min(Start, Length);
+ return StringRef(Data + Start, std::min(N, Length - Start));
+ }
+
+ /// Return a StringRef equal to 'this' but with the first \p N elements
+ /// dropped.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
+ StringRef drop_front(size_t N = 1) const {
+ assert(size() >= N && "Dropping more elements than exist");
+ return substr(N);
}
- /// slice - Return a reference to the substring from [Start, End).
+ /// Return a StringRef equal to 'this' but with the last \p N elements
+ /// dropped.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
+ StringRef drop_back(size_t N = 1) const {
+ assert(size() >= N && "Dropping more elements than exist");
+ return substr(0, size()-N);
+ }
+
+ /// Return a reference to the substring from [Start, End).
///
- /// \param Start - The index of the starting character in the substring; if
+ /// \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 less than \arg Start, or exceeds the
+ /// \param End The index following the last character to include in the
+ /// substring. If this is npos, or less than \p Start, or exceeds the
/// number of characters remaining in the string, the string suffix
- /// (starting with \arg Start) will be returned.
+ /// (starting with \p Start) will be returned.
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
StringRef slice(size_t Start, size_t End) const {
- Start = min(Start, Length);
- End = min(max(Start, End), Length);
+ Start = std::min(Start, Length);
+ End = std::min(std::max(Start, End), Length);
return StringRef(Data + Start, End - Start);
}
- /// split - Split into two substrings around the first occurrence of a
- /// separator character.
+ /// Split into two substrings around the first occurrence of a separator
+ /// character.
///
- /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+ /// 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 \arg Separator is not in the string, then the result is a
+ /// 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.
- /// \return - The split substrings.
+ /// \param Separator The character to split on.
+ /// \returns The split substrings.
std::pair<StringRef, StringRef> split(char Separator) const {
size_t Idx = find(Separator);
if (Idx == npos)
return std::make_pair(slice(0, Idx), slice(Idx+1, npos));
}
- /// split - Split into two substrings around the first occurrence of a
- /// separator string.
+ /// Split into two substrings around the first occurrence of a separator
+ /// string.
///
- /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+ /// 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 \arg Separator is not in the string, then the result is a
+ /// 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 std::make_pair(slice(0, Idx), slice(Idx + Separator.size(), npos));
}
- /// split - Split into substrings around the occurrences of a separator
- /// string.
+ /// Split into substrings around the occurrences of a separator string.
///
- /// Each substring is stored in \arg A. If \arg MaxSplit is >= 0, at most
- /// \arg MaxSplit splits are done and consequently <= \arg MaxSplit
+ /// 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 \arg KeepEmpty is false, empty strings are not added to \arg A. They
- /// still count when considering \arg MaxSplit
+ /// 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
///
StringRef Separator, int MaxSplit = -1,
bool KeepEmpty = true) const;
- /// rsplit - Split into two substrings around the last occurrence of a
- /// separator character.
+ /// Split into substrings around the occurrences of a separator character.
///
- /// If \arg Separator is in the string, then the result is a pair (LHS, RHS)
+ /// 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 \arg Separator is not in the string, then the result is a
+ /// 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 std::make_pair(slice(0, Idx), slice(Idx+1, npos));
}
+ /// Return string with consecutive characters in \p Chars starting from
+ /// the left removed.
+ 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 characters in \p Chars starting from
+ /// the right removed.
+ 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 characters in \p Chars starting from
+ /// the left and right removed.
+ StringRef trim(StringRef Chars = " \t\n\v\f\r") const {
+ return ltrim(Chars).rtrim(Chars);
+ }
+
/// @}
};
/// @name StringRef Comparison Operators
/// @{
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
inline bool operator==(StringRef LHS, StringRef RHS) {
return LHS.equals(RHS);
}
+ LLVM_ATTRIBUTE_ALWAYS_INLINE
inline bool operator!=(StringRef LHS, StringRef RHS) {
return !(LHS == RHS);
}
return LHS.compare(RHS) != -1;
}
+ inline std::string &operator+=(std::string &buffer, StringRef string) {
+ return buffer.append(string.data(), string.size());
+ }
+
/// @}
+ /// \brief Compute a hash_code for a StringRef.
+ hash_code hash_value(StringRef S);
+
+ // StringRefs can be treated like a POD type.
+ template <typename T> struct isPodLike;
+ template <> struct isPodLike<StringRef> { static const bool value = true; };
}
#endif