1//===-- llvm/ADT/StringExtras.h - Useful string functions -------*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file contains some functions that are useful when dealing with strings. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_ADT_STRINGEXTRAS_H 15#define LLVM_ADT_STRINGEXTRAS_H 16 17#include "llvm/Support/DataTypes.h" 18#include "llvm/ADT/StringRef.h" 19 20namespace llvm { 21template<typename T> class SmallVectorImpl; 22 23/// hexdigit - Return the hexadecimal character for the 24/// given number \arg X (which should be less than 16). 25static inline char hexdigit(unsigned X, bool LowerCase = false) { 26 const char HexChar = LowerCase ? 'a' : 'A'; 27 return X < 10 ? '0' + X : HexChar + X - 10; 28} 29 30/// utohex_buffer - Emit the specified number into the buffer specified by 31/// BufferEnd, returning a pointer to the start of the string. This can be used 32/// like this: (note that the buffer must be large enough to handle any number): 33/// char Buffer[40]; 34/// printf("0x%s", utohex_buffer(X, Buffer+40)); 35/// 36/// This should only be used with unsigned types. 37/// 38template<typename IntTy> 39static inline char *utohex_buffer(IntTy X, char *BufferEnd) { 40 char *BufPtr = BufferEnd; 41 *--BufPtr = 0; // Null terminate buffer. 42 if (X == 0) { 43 *--BufPtr = '0'; // Handle special case. 44 return BufPtr; 45 } 46 47 while (X) { 48 unsigned char Mod = static_cast<unsigned char>(X) & 15; 49 *--BufPtr = hexdigit(Mod); 50 X >>= 4; 51 } 52 return BufPtr; 53} 54 55static inline std::string utohexstr(uint64_t X) { 56 char Buffer[17]; 57 return utohex_buffer(X, Buffer+17); 58} 59 60static inline std::string utostr_32(uint32_t X, bool isNeg = false) { 61 char Buffer[11]; 62 char *BufPtr = Buffer+11; 63 64 if (X == 0) *--BufPtr = '0'; // Handle special case... 65 66 while (X) { 67 *--BufPtr = '0' + char(X % 10); 68 X /= 10; 69 } 70 71 if (isNeg) *--BufPtr = '-'; // Add negative sign... 72 73 return std::string(BufPtr, Buffer+11); 74} 75 76static inline std::string utostr(uint64_t X, bool isNeg = false) { 77 char Buffer[21]; 78 char *BufPtr = Buffer+21; 79 80 if (X == 0) *--BufPtr = '0'; // Handle special case... 81 82 while (X) { 83 *--BufPtr = '0' + char(X % 10); 84 X /= 10; 85 } 86 87 if (isNeg) *--BufPtr = '-'; // Add negative sign... 88 return std::string(BufPtr, Buffer+21); 89} 90 91 92static inline std::string itostr(int64_t X) { 93 if (X < 0) 94 return utostr(static_cast<uint64_t>(-X), true); 95 else 96 return utostr(static_cast<uint64_t>(X)); 97} 98 99/// StrInStrNoCase - Portable version of strcasestr. Locates the first 100/// occurrence of string 's1' in string 's2', ignoring case. Returns 101/// the offset of s2 in s1 or npos if s2 cannot be found. 102StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2); 103 104/// getToken - This function extracts one token from source, ignoring any 105/// leading characters that appear in the Delimiters string, and ending the 106/// token at any of the characters that appear in the Delimiters string. If 107/// there are no tokens in the source string, an empty string is returned. 108/// The function returns a pair containing the extracted token and the 109/// remaining tail string. 110std::pair<StringRef, StringRef> getToken(StringRef Source, 111 StringRef Delimiters = " \t\n\v\f\r"); 112 113/// SplitString - Split up the specified string according to the specified 114/// delimiters, appending the result fragments to the output list. 115void SplitString(StringRef Source, 116 SmallVectorImpl<StringRef> &OutFragments, 117 StringRef Delimiters = " \t\n\v\f\r"); 118 119/// HashString - Hash function for strings. 120/// 121/// This is the Bernstein hash function. 122// 123// FIXME: Investigate whether a modified bernstein hash function performs 124// better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx 125// X*33+c -> X*33^c 126static inline unsigned HashString(StringRef Str, unsigned Result = 0) { 127 for (unsigned i = 0, e = Str.size(); i != e; ++i) 128 Result = Result * 33 + (unsigned char)Str[i]; 129 return Result; 130} 131 132} // End llvm namespace 133 134#endif 135