llvm-6502/include/llvm/ADT/StringExtras.h
Benjamin Kramer e68e77569f Move ftostr into its last user (cppbackend) and simplify it a bit.
New code should use raw_ostream.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153326 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-23 11:26:29 +00:00

135 lines
4.2 KiB
C++

//===-- llvm/ADT/StringExtras.h - Useful string functions -------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file contains some functions that are useful when dealing with strings.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_STRINGEXTRAS_H
#define LLVM_ADT_STRINGEXTRAS_H
#include "llvm/Support/DataTypes.h"
#include "llvm/ADT/StringRef.h"
namespace llvm {
template<typename T> class SmallVectorImpl;
/// hexdigit - Return the hexadecimal character for the
/// given number \arg X (which should be less than 16).
static inline char hexdigit(unsigned X, bool LowerCase = false) {
const char HexChar = LowerCase ? 'a' : 'A';
return X < 10 ? '0' + X : HexChar + X - 10;
}
/// utohex_buffer - Emit the specified number into the buffer specified by
/// BufferEnd, returning a pointer to the start of the string. This can be used
/// like this: (note that the buffer must be large enough to handle any number):
/// char Buffer[40];
/// printf("0x%s", utohex_buffer(X, Buffer+40));
///
/// This should only be used with unsigned types.
///
template<typename IntTy>
static inline char *utohex_buffer(IntTy X, char *BufferEnd) {
char *BufPtr = BufferEnd;
*--BufPtr = 0; // Null terminate buffer.
if (X == 0) {
*--BufPtr = '0'; // Handle special case.
return BufPtr;
}
while (X) {
unsigned char Mod = static_cast<unsigned char>(X) & 15;
*--BufPtr = hexdigit(Mod);
X >>= 4;
}
return BufPtr;
}
static inline std::string utohexstr(uint64_t X) {
char Buffer[17];
return utohex_buffer(X, Buffer+17);
}
static inline std::string utostr_32(uint32_t X, bool isNeg = false) {
char Buffer[11];
char *BufPtr = Buffer+11;
if (X == 0) *--BufPtr = '0'; // Handle special case...
while (X) {
*--BufPtr = '0' + char(X % 10);
X /= 10;
}
if (isNeg) *--BufPtr = '-'; // Add negative sign...
return std::string(BufPtr, Buffer+11);
}
static inline std::string utostr(uint64_t X, bool isNeg = false) {
char Buffer[21];
char *BufPtr = Buffer+21;
if (X == 0) *--BufPtr = '0'; // Handle special case...
while (X) {
*--BufPtr = '0' + char(X % 10);
X /= 10;
}
if (isNeg) *--BufPtr = '-'; // Add negative sign...
return std::string(BufPtr, Buffer+21);
}
static inline std::string itostr(int64_t X) {
if (X < 0)
return utostr(static_cast<uint64_t>(-X), true);
else
return utostr(static_cast<uint64_t>(X));
}
/// StrInStrNoCase - Portable version of strcasestr. Locates the first
/// occurrence of string 's1' in string 's2', ignoring case. Returns
/// the offset of s2 in s1 or npos if s2 cannot be found.
StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2);
/// getToken - This function extracts one token from source, ignoring any
/// leading characters that appear in the Delimiters string, and ending the
/// token at any of the characters that appear in the Delimiters string. If
/// there are no tokens in the source string, an empty string is returned.
/// The function returns a pair containing the extracted token and the
/// remaining tail string.
std::pair<StringRef, StringRef> getToken(StringRef Source,
StringRef Delimiters = " \t\n\v\f\r");
/// SplitString - Split up the specified string according to the specified
/// delimiters, appending the result fragments to the output list.
void SplitString(StringRef Source,
SmallVectorImpl<StringRef> &OutFragments,
StringRef Delimiters = " \t\n\v\f\r");
/// HashString - Hash function for strings.
///
/// This is the Bernstein hash function.
//
// FIXME: Investigate whether a modified bernstein hash function performs
// better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx
// X*33+c -> X*33^c
static inline unsigned HashString(StringRef Str, unsigned Result = 0) {
for (unsigned i = 0, e = Str.size(); i != e; ++i)
Result = Result * 33 + Str[i];
return Result;
}
} // End llvm namespace
#endif