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Diffstat (limited to 'lib/Support/StringRef.cpp')
-rw-r--r-- | lib/Support/StringRef.cpp | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/lib/Support/StringRef.cpp b/lib/Support/StringRef.cpp new file mode 100644 index 0000000..deaa19e --- /dev/null +++ b/lib/Support/StringRef.cpp @@ -0,0 +1,188 @@ +//===-- StringRef.cpp - Lightweight String References ---------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/ADT/StringRef.h" +using namespace llvm; + +// MSVC emits references to this into the translation units which reference it. +#ifndef _MSC_VER +const size_t StringRef::npos; +#endif + +//===----------------------------------------------------------------------===// +// String Searching +//===----------------------------------------------------------------------===// + + +/// find - Search for the first string \arg Str in the string. +/// +/// \return - The index of the first occurence of \arg Str, or npos if not +/// found. +size_t StringRef::find(const StringRef &Str) const { + size_t N = Str.size(); + if (N > Length) + return npos; + for (size_t i = 0, e = Length - N + 1; i != e; ++i) + if (substr(i, N).equals(Str)) + return i; + return npos; +} + +/// rfind - Search for the last string \arg Str in the string. +/// +/// \return - The index of the last occurence of \arg Str, or npos if not +/// found. +size_t StringRef::rfind(const 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; +} + +/// find_first_of - Find the first character from the string 'Chars' in the +/// current string or return npos if not in string. +StringRef::size_type StringRef::find_first_of(StringRef Chars) const { + for (size_type i = 0, e = Length; i != e; ++i) + if (Chars.find(Data[i]) != npos) + return i; + return npos; +} + +/// find_first_not_of - Find the first character in the string that is not +/// in the string 'Chars' or return npos if all are in string. Same as find. +StringRef::size_type StringRef::find_first_not_of(StringRef Chars) const { + for (size_type i = 0, e = Length; i != e; ++i) + if (Chars.find(Data[i]) == npos) + return i; + return npos; +} + + +//===----------------------------------------------------------------------===// +// Helpful Algorithms +//===----------------------------------------------------------------------===// + +/// count - Return the number of non-overlapped occurrences of \arg Str in +/// the string. +size_t StringRef::count(const 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; +} + +/// 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) { + // Autosense radix if not specified. + if (Radix == 0) { + if (Str.startswith("0x")) { + Str = Str.substr(2); + Radix = 16; + } else if (Str.startswith("0b")) { + Str = Str.substr(2); + Radix = 2; + } else if (Str.startswith("0")) + Radix = 8; + else + Radix = 10; + } + + // 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. + Result = 0; + while (!Str.empty()) { + unsigned CharVal; + if (Str[0] >= '0' && Str[0] <= '9') + CharVal = Str[0]-'0'; + else if (Str[0] >= 'a' && Str[0] <= 'z') + CharVal = Str[0]-'a'+10; + else if (Str[0] >= 'A' && Str[0] <= 'Z') + CharVal = Str[0]-'A'+10; + else + return true; + + // If the parsed value is larger than the integer radix, the string is + // invalid. + if (CharVal >= Radix) + return true; + + // Add in this character. + unsigned long long PrevResult = Result; + Result = Result*Radix+CharVal; + + // Check for overflow. + if (Result < 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 { + unsigned long long ULLVal; + + // Handle positive strings first. + if (empty() || front() != '-') { + if (GetAsUnsignedInteger(*this, 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. + if (GetAsUnsignedInteger(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. + (long long)-ULLVal > 0) + return true; + + Result = -ULLVal; + 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; +} |