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Diffstat (limited to 'third_party/llvm-project/StringRef.cpp')
| -rw-r--r-- | third_party/llvm-project/StringRef.cpp | 519 |
1 files changed, 519 insertions, 0 deletions
diff --git a/third_party/llvm-project/StringRef.cpp b/third_party/llvm-project/StringRef.cpp new file mode 100644 index 000000000..08af7eaac --- /dev/null +++ b/third_party/llvm-project/StringRef.cpp @@ -0,0 +1,519 @@ +//===-- StringRef.cpp - Lightweight String References ---------------------===// +// +// 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 +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/StringRef.h" +#include "llvm/ADT/APFloat.h" +#include "llvm/ADT/APInt.h" +#include "llvm/ADT/Hashing.h" +#include "llvm/ADT/StringExtras.h" +#include "llvm/ADT/edit_distance.h" +#include <bitset> + +using namespace llvm; + +// MSVC emits references to this into the translation units which reference it. +#ifndef _MSC_VER +const size_t StringRef::npos; +#endif + +// strncasecmp() is not available on non-POSIX systems, so define an +// alternative function here. +static int ascii_strncasecmp(const char *LHS, const char *RHS, size_t Length) { + for (size_t I = 0; I < Length; ++I) { + unsigned char LHC = toLower(LHS[I]); + unsigned char RHC = toLower(RHS[I]); + if (LHC != RHC) + return LHC < RHC ? -1 : 1; + } + return 0; +} + +/// compare_lower - Compare strings, ignoring case. +int StringRef::compare_lower(StringRef RHS) const { + if (int Res = ascii_strncasecmp(Data, RHS.Data, std::min(Length, RHS.Length))) + return Res; + if (Length == RHS.Length) + return 0; + return Length < RHS.Length ? -1 : 1; +} + +/// Check if this string starts with the given \p Prefix, ignoring case. +bool StringRef::startswith_lower(StringRef Prefix) const { + return Length >= Prefix.Length && + ascii_strncasecmp(Data, Prefix.Data, Prefix.Length) == 0; +} + +/// Check if this string ends with the given \p Suffix, ignoring case. +bool StringRef::endswith_lower(StringRef Suffix) const { + return Length >= Suffix.Length && + ascii_strncasecmp(end() - Suffix.Length, Suffix.Data, Suffix.Length) == 0; +} + +size_t StringRef::find_lower(char C, size_t From) const { + char L = toLower(C); + return find_if([L](char D) { return toLower(D) == L; }, From); +} + +/// compare_numeric - Compare strings, handle embedded numbers. +int StringRef::compare_numeric(StringRef RHS) const { + for (size_t I = 0, E = std::min(Length, RHS.Length); I != E; ++I) { + // Check for sequences of digits. + if (isDigit(Data[I]) && isDigit(RHS.Data[I])) { + // The longer sequence of numbers is considered larger. + // This doesn't really handle prefixed zeros well. + size_t J; + for (J = I + 1; J != E + 1; ++J) { + bool ld = J < Length && isDigit(Data[J]); + bool rd = J < RHS.Length && isDigit(RHS.Data[J]); + if (ld != rd) + return rd ? -1 : 1; + if (!rd) + break; + } + // The two number sequences have the same length (J-I), just memcmp them. + if (int Res = compareMemory(Data + I, RHS.Data + I, J - I)) + return Res < 0 ? -1 : 1; + // Identical number sequences, continue search after the numbers. + I = J - 1; + continue; + } + if (Data[I] != RHS.Data[I]) + return (unsigned char)Data[I] < (unsigned char)RHS.Data[I] ? -1 : 1; + } + if (Length == RHS.Length) + return 0; + return Length < RHS.Length ? -1 : 1; +} + +// Compute the edit distance between the two given strings. +unsigned StringRef::edit_distance(llvm::StringRef Other, + bool AllowReplacements, + unsigned MaxEditDistance) const { + return llvm::ComputeEditDistance( + makeArrayRef(data(), size()), + makeArrayRef(Other.data(), Other.size()), + AllowReplacements, MaxEditDistance); +} + +//===----------------------------------------------------------------------===// +// String Operations +//===----------------------------------------------------------------------===// + +std::string StringRef::lower() const { + std::string Result(size(), char()); + for (size_type i = 0, e = size(); i != e; ++i) { + Result[i] = toLower(Data[i]); + } + return Result; +} + +std::string StringRef::upper() const { + std::string Result(size(), char()); + for (size_type i = 0, e = size(); i != e; ++i) { + Result[i] = toUpper(Data[i]); + } + return Result; +} + +//===----------------------------------------------------------------------===// +// String Searching +//===----------------------------------------------------------------------===// + + +/// find - Search for the first string \arg Str in the string. +/// +/// \return - The index of the first occurrence of \arg Str, or npos if not +/// found. +size_t StringRef::find(StringRef Str, size_t From) const { + if (From > Length) + return npos; + + const char *Start = Data + From; + size_t Size = Length - From; + + const char *Needle = Str.data(); + size_t N = Str.size(); + if (N == 0) + return From; + if (Size < N) + return npos; + if (N == 1) { + const char *Ptr = (const char *)::memchr(Start, Needle[0], Size); + return Ptr == nullptr ? npos : Ptr - Data; + } + + const char *Stop = Start + (Size - N + 1); + + // For short haystacks or unsupported needles fall back to the naive algorithm + if (Size < 16 || N > 255) { + do { + if (std::memcmp(Start, Needle, N) == 0) + return Start - Data; + ++Start; + } while (Start < Stop); + return npos; + } + + // Build the bad char heuristic table, with uint8_t to reduce cache thrashing. + uint8_t BadCharSkip[256]; + std::memset(BadCharSkip, N, 256); + for (unsigned i = 0; i != N-1; ++i) + BadCharSkip[(uint8_t)Str[i]] = N-1-i; + + do { + uint8_t Last = Start[N - 1]; + if (LLVM_UNLIKELY(Last == (uint8_t)Needle[N - 1])) + if (std::memcmp(Start, Needle, N - 1) == 0) + return Start - Data; + + // Otherwise skip the appropriate number of bytes. + Start += BadCharSkip[Last]; + } while (Start < Stop); + + return npos; +} + +size_t StringRef::find_lower(StringRef Str, size_t From) const { + StringRef This = substr(From); + while (This.size() >= Str.size()) { + if (This.startswith_lower(Str)) + return From; + This = This.drop_front(); + ++From; + } + return npos; +} + +size_t StringRef::rfind_lower(char C, size_t From) const { + From = std::min(From, Length); + size_t i = From; + while (i != 0) { + --i; + if (toLower(Data[i]) == toLower(C)) + return i; + } + return npos; +} + +/// rfind - Search for the last string \arg Str in the string. +/// +/// \return - The index of the last occurrence of \arg Str, or npos if not +/// found. +size_t StringRef::rfind(StringRef Str) const { + size_t N = Str.size(); + if (N > Length) + return npos; + for (size_t i = Length - N + 1, e = 0; i != e;) { + --i; + if (substr(i, N).equals(Str)) + return i; + } + return npos; +} + +size_t StringRef::rfind_lower(StringRef Str) const { + size_t N = Str.size(); + if (N > Length) + return npos; + for (size_t i = Length - N + 1, e = 0; i != e;) { + --i; + if (substr(i, N).equals_lower(Str)) + return i; + } + return npos; +} + +/// find_first_of - Find the first character in the string that is in \arg +/// Chars, or npos if not found. +/// +/// Note: O(size() + Chars.size()) +StringRef::size_type StringRef::find_first_of(StringRef Chars, + size_t From) const { + std::bitset<1 << CHAR_BIT> CharBits; + for (size_type i = 0; i != Chars.size(); ++i) + CharBits.set((unsigned char)Chars[i]); + + for (size_type i = std::min(From, Length), e = Length; i != e; ++i) + if (CharBits.test((unsigned char)Data[i])) + return i; + return npos; +} + +/// find_first_not_of - Find the first character in the string that is not +/// \arg C or npos if not found. +StringRef::size_type StringRef::find_first_not_of(char C, size_t From) const { + for (size_type i = std::min(From, Length), e = Length; i != e; ++i) + if (Data[i] != C) + return i; + return npos; +} + +/// find_first_not_of - Find the first character in the string that is not +/// in the string \arg Chars, or npos if not found. +/// +/// Note: O(size() + Chars.size()) +StringRef::size_type StringRef::find_first_not_of(StringRef Chars, + size_t From) const { + std::bitset<1 << CHAR_BIT> CharBits; + for (size_type i = 0; i != Chars.size(); ++i) + CharBits.set((unsigned char)Chars[i]); + + for (size_type i = std::min(From, Length), e = Length; i != e; ++i) + if (!CharBits.test((unsigned char)Data[i])) + return i; + return npos; +} + +/// find_last_of - Find the last character in the string that is in \arg C, +/// or npos if not found. +/// +/// Note: O(size() + Chars.size()) +StringRef::size_type StringRef::find_last_of(StringRef Chars, + size_t From) const { + std::bitset<1 << CHAR_BIT> CharBits; + for (size_type i = 0; i != Chars.size(); ++i) + CharBits.set((unsigned char)Chars[i]); + + for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i) + if (CharBits.test((unsigned char)Data[i])) + return i; + return npos; +} + +/// find_last_not_of - Find the last character in the string that is not +/// \arg C, or npos if not found. +StringRef::size_type StringRef::find_last_not_of(char C, size_t From) const { + for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i) + if (Data[i] != C) + return i; + return npos; +} + +/// find_last_not_of - Find the last character in the string that is not in +/// \arg Chars, or npos if not found. +/// +/// Note: O(size() + Chars.size()) +StringRef::size_type StringRef::find_last_not_of(StringRef Chars, + size_t From) const { + std::bitset<1 << CHAR_BIT> CharBits; + for (size_type i = 0, e = Chars.size(); i != e; ++i) + CharBits.set((unsigned char)Chars[i]); + + for (size_type i = std::min(From, Length) - 1, e = -1; i != e; --i) + if (!CharBits.test((unsigned char)Data[i])) + return i; + return npos; +} + +void StringRef::split(SmallVectorImpl<StringRef> &A, + StringRef Separator, int MaxSplit, + bool KeepEmpty) const { + StringRef S = *this; + + // Count down from MaxSplit. When MaxSplit is -1, this will just split + // "forever". This doesn't support splitting more than 2^31 times + // intentionally; if we ever want that we can make MaxSplit a 64-bit integer + // but that seems unlikely to be useful. + while (MaxSplit-- != 0) { + size_t Idx = S.find(Separator); + if (Idx == npos) + break; + + // Push this split. + if (KeepEmpty || Idx > 0) + A.push_back(S.slice(0, Idx)); + + // Jump forward. + S = S.slice(Idx + Separator.size(), npos); + } + + // Push the tail. + if (KeepEmpty || !S.empty()) + A.push_back(S); +} + +void StringRef::split(SmallVectorImpl<StringRef> &A, char Separator, + int MaxSplit, bool KeepEmpty) const { + StringRef S = *this; + + // Count down from MaxSplit. When MaxSplit is -1, this will just split + // "forever". This doesn't support splitting more than 2^31 times + // intentionally; if we ever want that we can make MaxSplit a 64-bit integer + // but that seems unlikely to be useful. + while (MaxSplit-- != 0) { + size_t Idx = S.find(Separator); + if (Idx == npos) + break; + + // Push this split. + if (KeepEmpty || Idx > 0) + A.push_back(S.slice(0, Idx)); + + // Jump forward. + S = S.slice(Idx + 1, npos); + } + + // Push the tail. + if (KeepEmpty || !S.empty()) + A.push_back(S); +} + +//===----------------------------------------------------------------------===// +// Helpful Algorithms +//===----------------------------------------------------------------------===// + +/// count - Return the number of non-overlapped occurrences of \arg Str in +/// the string. +size_t StringRef::count(StringRef Str) const { + size_t Count = 0; + size_t N = Str.size(); + if (N > Length) + return 0; + for (size_t i = 0, e = Length - N + 1; i != e; ++i) + if (substr(i, N).equals(Str)) + ++Count; + return Count; +} + +static unsigned GetAutoSenseRadix(StringRef &Str) { + if (Str.empty()) + return 10; + + if (Str.startswith("0x") || Str.startswith("0X")) { + Str = Str.substr(2); + return 16; + } + + if (Str.startswith("0b") || Str.startswith("0B")) { + Str = Str.substr(2); + return 2; + } + + if (Str.startswith("0o")) { + Str = Str.substr(2); + return 8; + } + + if (Str[0] == '0' && Str.size() > 1 && isDigit(Str[1])) { + Str = Str.substr(1); + return 8; + } + + return 10; +} + +bool llvm::consumeUnsignedInteger(StringRef &Str, unsigned Radix, + unsigned long long &Result) { + // Autosense radix if not specified. + if (Radix == 0) + Radix = GetAutoSenseRadix(Str); + + // Empty strings (after the radix autosense) are invalid. + if (Str.empty()) return true; + + // Parse all the bytes of the string given this radix. Watch for overflow. + StringRef Str2 = Str; + Result = 0; + while (!Str2.empty()) { + unsigned CharVal; + if (Str2[0] >= '0' && Str2[0] <= '9') + CharVal = Str2[0] - '0'; + else if (Str2[0] >= 'a' && Str2[0] <= 'z') + CharVal = Str2[0] - 'a' + 10; + else if (Str2[0] >= 'A' && Str2[0] <= 'Z') + CharVal = Str2[0] - 'A' + 10; + else + break; + + // If the parsed value is larger than the integer radix, we cannot + // consume any more characters. + if (CharVal >= Radix) + break; + + // Add in this character. + unsigned long long PrevResult = Result; + Result = Result * Radix + CharVal; + + // Check for overflow by shifting back and seeing if bits were lost. + if (Result / Radix < PrevResult) + return true; + + Str2 = Str2.substr(1); + } + + // We consider the operation a failure if no characters were consumed + // successfully. + if (Str.size() == Str2.size()) + return true; + + Str = Str2; + return false; +} + +bool llvm::consumeSignedInteger(StringRef &Str, unsigned Radix, + long long &Result) { + unsigned long long ULLVal; + + // Handle positive strings first. + if (Str.empty() || Str.front() != '-') { + if (consumeUnsignedInteger(Str, Radix, ULLVal) || + // Check for value so large it overflows a signed value. + (long long)ULLVal < 0) + return true; + Result = ULLVal; + return false; + } + + // Get the positive part of the value. + StringRef Str2 = Str.drop_front(1); + if (consumeUnsignedInteger(Str2, Radix, ULLVal) || + // Reject values so large they'd overflow as negative signed, but allow + // "-0". This negates the unsigned so that the negative isn't undefined + // on signed overflow. + (long long)-ULLVal > 0) + return true; + + Str = Str2; + Result = -ULLVal; + return false; +} + +/// GetAsUnsignedInteger - Workhorse method that converts a integer character +/// sequence of radix up to 36 to an unsigned long long value. +bool llvm::getAsUnsignedInteger(StringRef Str, unsigned Radix, + unsigned long long &Result) { + if (consumeUnsignedInteger(Str, Radix, Result)) + return true; + + // For getAsUnsignedInteger, we require the whole string to be consumed or + // else we consider it a failure. + return !Str.empty(); +} + +bool llvm::getAsSignedInteger(StringRef Str, unsigned Radix, + long long &Result) { + if (consumeSignedInteger(Str, Radix, Result)) + return true; + + // For getAsSignedInteger, we require the whole string to be consumed or else + // we consider it a failure. + return !Str.empty(); +} + +bool StringRef::getAsInteger(unsigned Radix, APInt &Result) const { + llvm_unreachable("getAsinteger"); +} + +bool StringRef::getAsDouble(double &Result, bool AllowInexact) const { + llvm_unreachable("getAsDouble"); +} + +// Implementation of StringRef hashing. +hash_code llvm::hash_value(StringRef S) { + return hash_combine_range(S.begin(), S.end()); +} |