#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/APInt.h"
-#include "llvm/ADT/OwningPtr.h"
+#include "llvm/ADT/Hashing.h"
+#include "llvm/ADT/edit_distance.h"
#include <bitset>
using namespace llvm;
return x;
}
+static char ascii_toupper(char x) {
+ if (x >= 'a' && x <= 'z')
+ return x - 'a' + 'A';
+ return x;
+}
+
static bool ascii_isdigit(char x) {
return x >= '0' && x <= '9';
}
-/// compare_lower - Compare strings, ignoring case.
-int StringRef::compare_lower(StringRef RHS) const {
- for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) {
- unsigned char LHC = ascii_tolower(Data[I]);
- unsigned char RHC = ascii_tolower(RHS.Data[I]);
+// 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 = ascii_tolower(LHS[I]);
+ unsigned char RHC = ascii_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, 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;
+}
+
/// compare_numeric - Compare strings, handle embedded numbers.
int StringRef::compare_numeric(StringRef RHS) const {
for (size_t I = 0, E = min(Length, RHS.Length); I != E; ++I) {
- if (Data[I] == RHS.Data[I])
- continue;
+ // Check for sequences of digits.
if (ascii_isdigit(Data[I]) && ascii_isdigit(RHS.Data[I])) {
- // The longer sequence of numbers is larger. This doesn't really handle
- // prefixed zeros well.
- for (size_t J = I+1; J != E+1; ++J) {
+ // 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 && ascii_isdigit(Data[J]);
bool rd = J < RHS.Length && ascii_isdigit(RHS.Data[J]);
if (ld != rd)
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;
}
- return (unsigned char)Data[I] < (unsigned char)RHS.Data[I] ? -1 : 1;
+ if (Data[I] != RHS.Data[I])
+ return (unsigned char)Data[I] < (unsigned char)RHS.Data[I] ? -1 : 1;
}
if (Length == RHS.Length)
return 0;
// Compute the edit distance between the two given strings.
unsigned StringRef::edit_distance(llvm::StringRef Other,
bool AllowReplacements,
- unsigned MaxEditDistance) {
- // The algorithm implemented below is the "classic"
- // dynamic-programming algorithm for computing the Levenshtein
- // distance, which is described here:
- //
- // http://en.wikipedia.org/wiki/Levenshtein_distance
- //
- // Although the algorithm is typically described using an m x n
- // array, only two rows are used at a time, so this implemenation
- // just keeps two separate vectors for those two rows.
- size_type m = size();
- size_type n = Other.size();
-
- const unsigned SmallBufferSize = 64;
- unsigned SmallBuffer[SmallBufferSize];
- llvm::OwningArrayPtr<unsigned> Allocated;
- unsigned *previous = SmallBuffer;
- if (2*(n + 1) > SmallBufferSize) {
- previous = new unsigned [2*(n+1)];
- Allocated.reset(previous);
- }
- unsigned *current = previous + (n + 1);
-
- for (unsigned i = 0; i <= n; ++i)
- previous[i] = i;
-
- for (size_type y = 1; y <= m; ++y) {
- current[0] = y;
- unsigned BestThisRow = current[0];
-
- for (size_type x = 1; x <= n; ++x) {
- if (AllowReplacements) {
- current[x] = min(previous[x-1] + ((*this)[y-1] == Other[x-1]? 0u:1u),
- min(current[x-1], previous[x])+1);
- }
- else {
- if ((*this)[y-1] == Other[x-1]) current[x] = previous[x-1];
- else current[x] = min(current[x-1], previous[x]) + 1;
- }
- BestThisRow = min(BestThisRow, current[x]);
- }
+ unsigned MaxEditDistance) const {
+ return llvm::ComputeEditDistance(
+ llvm::ArrayRef<char>(data(), size()),
+ llvm::ArrayRef<char>(Other.data(), Other.size()),
+ AllowReplacements, MaxEditDistance);
+}
- if (MaxEditDistance && BestThisRow > MaxEditDistance)
- return MaxEditDistance + 1;
+//===----------------------------------------------------------------------===//
+// String Operations
+//===----------------------------------------------------------------------===//
- unsigned *tmp = current;
- current = previous;
- previous = tmp;
+std::string StringRef::lower() const {
+ std::string Result(size(), char());
+ for (size_type i = 0, e = size(); i != e; ++i) {
+ Result[i] = ascii_tolower(Data[i]);
}
+ return Result;
+}
- unsigned Result = previous[n];
+std::string StringRef::upper() const {
+ std::string Result(size(), char());
+ for (size_type i = 0, e = size(); i != e; ++i) {
+ Result[i] = ascii_toupper(Data[i]);
+ }
return Result;
}
size_t N = Str.size();
if (N > Length)
return npos;
- for (size_t e = Length - N + 1, i = min(From, e); i != e; ++i)
- if (substr(i, N).equals(Str))
- return i;
+
+ // For short haystacks or unsupported needles fall back to the naive algorithm
+ if (Length < 16 || N > 255 || N == 0) {
+ for (size_t e = Length - N + 1, i = min(From, e); i != e; ++i)
+ if (substr(i, N).equals(Str))
+ return i;
+ return npos;
+ }
+
+ if (From >= Length)
+ 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;
+
+ unsigned Len = Length-From, Pos = From;
+ while (Len >= N) {
+ if (substr(Pos, N).equals(Str)) // See if this is the correct substring.
+ return Pos;
+
+ // Otherwise skip the appropriate number of bytes.
+ uint8_t Skip = BadCharSkip[(uint8_t)(*this)[Pos+N-1]];
+ Len -= Skip;
+ Pos += Skip;
+ }
+
return npos;
}
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 = 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 = 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 Separators, int MaxSplit,
+ bool KeepEmpty) const {
+ StringRef rest = *this;
+
+ // rest.data() is used to distinguish cases like "a," that splits into
+ // "a" + "" and "a" that splits into "a" + 0.
+ for (int splits = 0;
+ rest.data() != NULL && (MaxSplit < 0 || splits < MaxSplit);
+ ++splits) {
+ std::pair<StringRef, StringRef> p = rest.split(Separators);
+
+ if (KeepEmpty || p.first.size() != 0)
+ A.push_back(p.first);
+ rest = p.second;
+ }
+ // If we have a tail left, add it.
+ if (rest.data() != NULL && (rest.size() != 0 || KeepEmpty))
+ A.push_back(rest);
+}
+
//===----------------------------------------------------------------------===//
// Helpful Algorithms
//===----------------------------------------------------------------------===//
if (Str.startswith("0x")) {
Str = Str.substr(2);
return 16;
- } else if (Str.startswith("0b")) {
+ }
+
+ if (Str.startswith("0b")) {
Str = Str.substr(2);
return 2;
- } else if (Str.startswith("0")) {
+ }
+
+ if (Str.startswith("0o")) {
+ Str = Str.substr(2);
return 8;
- } else {
- return 10;
}
+
+ if (Str.startswith("0"))
+ return 8;
+
+ return 10;
}
/// GetAsUnsignedInteger - Workhorse method that converts a integer character
/// sequence of radix up to 36 to an unsigned long long value.
-static bool GetAsUnsignedInteger(StringRef Str, unsigned Radix,
- unsigned long long &Result) {
+bool llvm::getAsUnsignedInteger(StringRef Str, unsigned Radix,
+ unsigned long long &Result) {
// Autosense radix if not specified.
if (Radix == 0)
Radix = GetAutoSenseRadix(Str);
unsigned long long PrevResult = Result;
Result = Result*Radix+CharVal;
- // Check for overflow.
- if (Result < PrevResult)
+ // Check for overflow by shifting back and seeing if bits were lost.
+ if (Result/Radix < PrevResult)
return true;
Str = Str.substr(1);
return false;
}
-bool StringRef::getAsInteger(unsigned Radix, unsigned long long &Result) const {
- return GetAsUnsignedInteger(*this, Radix, Result);
-}
-
-
-bool StringRef::getAsInteger(unsigned Radix, long long &Result) const {
+bool llvm::getAsSignedInteger(StringRef Str, unsigned Radix,
+ long long &Result) {
unsigned long long ULLVal;
// Handle positive strings first.
- if (empty() || front() != '-') {
- if (GetAsUnsignedInteger(*this, Radix, ULLVal) ||
+ if (Str.empty() || Str.front() != '-') {
+ if (getAsUnsignedInteger(Str, Radix, ULLVal) ||
// Check for value so large it overflows a signed value.
(long long)ULLVal < 0)
return true;
}
// Get the positive part of the value.
- if (GetAsUnsignedInteger(substr(1), Radix, ULLVal) ||
+ if (getAsUnsignedInteger(Str.substr(1), 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.
return false;
}
-bool StringRef::getAsInteger(unsigned Radix, int &Result) const {
- long long Val;
- if (getAsInteger(Radix, Val) ||
- (int)Val != Val)
- return true;
- Result = Val;
- return false;
-}
-
-bool StringRef::getAsInteger(unsigned Radix, unsigned &Result) const {
- unsigned long long Val;
- if (getAsInteger(Radix, Val) ||
- (unsigned)Val != Val)
- return true;
- Result = Val;
- return false;
-}
-
bool StringRef::getAsInteger(unsigned Radix, APInt &Result) const {
StringRef Str = *this;
unsigned BitWidth = Log2Radix * Str.size();
if (BitWidth < Result.getBitWidth())
BitWidth = Result.getBitWidth(); // don't shrink the result
- else
+ else if (BitWidth > Result.getBitWidth())
Result = Result.zext(BitWidth);
APInt RadixAP, CharAP; // unused unless !IsPowerOf2Radix
return false;
}
+
+
+// Implementation of StringRef hashing.
+hash_code llvm::hash_value(StringRef S) {
+ return hash_combine_range(S.begin(), S.end());
+}