llvm-6502/lib/Support/StringRef.cpp
Chris Lattner 05a32c8ab1 move a couple non-trivial methods out of line, add new
find_first_of/find_first_of methods.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82347 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-20 01:22:16 +00:00

193 lines
5.3 KiB
C++

//===-- 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;
const size_t StringRef::npos;
//===----------------------------------------------------------------------===//
// 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[0] != '0') {
Radix = 10;
} else {
if (Str.size() < 2) {
Radix = 8;
} else {
if (Str[1] == 'x') {
Str = Str.substr(2);
Radix = 16;
} else if (Str[1] == 'b') {
Str = Str.substr(2);
Radix = 2;
} else {
Radix = 8;
}
}
}
}
// 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;
}