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/APFloat.h" 19 #include "llvm/ADT/StringRef.h" 20 #include <cctype> 21 #include <cstdio> 22 #include <string> 23 24 namespace llvm { 25 template<typename T> class SmallVectorImpl; 26 27 /// hexdigit - Return the hexadecimal character for the 28 /// given number \arg X (which should be less than 16). 29 static inline char hexdigit(unsigned X, bool LowerCase = false) { 30 const char HexChar = LowerCase ? 'a' : 'A'; 31 return X < 10 ? '0' + X : HexChar + X - 10; 32 } 33 34 /// utohex_buffer - Emit the specified number into the buffer specified by 35 /// BufferEnd, returning a pointer to the start of the string. This can be used 36 /// like this: (note that the buffer must be large enough to handle any number): 37 /// char Buffer[40]; 38 /// printf("0x%s", utohex_buffer(X, Buffer+40)); 39 /// 40 /// This should only be used with unsigned types. 41 /// 42 template<typename IntTy> 43 static inline char *utohex_buffer(IntTy X, char *BufferEnd) { 44 char *BufPtr = BufferEnd; 45 *--BufPtr = 0; // Null terminate buffer. 46 if (X == 0) { 47 *--BufPtr = '0'; // Handle special case. 48 return BufPtr; 49 } 50 51 while (X) { 52 unsigned char Mod = static_cast<unsigned char>(X) & 15; 53 *--BufPtr = hexdigit(Mod); 54 X >>= 4; 55 } 56 return BufPtr; 57 } 58 59 static inline std::string utohexstr(uint64_t X) { 60 char Buffer[17]; 61 return utohex_buffer(X, Buffer+17); 62 } 63 64 static inline std::string utostr_32(uint32_t X, bool isNeg = false) { 65 char Buffer[11]; 66 char *BufPtr = Buffer+11; 67 68 if (X == 0) *--BufPtr = '0'; // Handle special case... 69 70 while (X) { 71 *--BufPtr = '0' + char(X % 10); 72 X /= 10; 73 } 74 75 if (isNeg) *--BufPtr = '-'; // Add negative sign... 76 77 return std::string(BufPtr, Buffer+11); 78 } 79 80 static inline std::string utostr(uint64_t X, bool isNeg = false) { 81 char Buffer[21]; 82 char *BufPtr = Buffer+21; 83 84 if (X == 0) *--BufPtr = '0'; // Handle special case... 85 86 while (X) { 87 *--BufPtr = '0' + char(X % 10); 88 X /= 10; 89 } 90 91 if (isNeg) *--BufPtr = '-'; // Add negative sign... 92 return std::string(BufPtr, Buffer+21); 93 } 94 95 96 static inline std::string itostr(int64_t X) { 97 if (X < 0) 98 return utostr(static_cast<uint64_t>(-X), true); 99 else 100 return utostr(static_cast<uint64_t>(X)); 101 } 102 103 static inline std::string ftostr(double V) { 104 char Buffer[200]; 105 sprintf(Buffer, "%20.6e", V); 106 char *B = Buffer; 107 while (*B == ' ') ++B; 108 return B; 109 } 110 111 static inline std::string ftostr(const APFloat& V) { 112 if (&V.getSemantics() == &APFloat::IEEEdouble) 113 return ftostr(V.convertToDouble()); 114 else if (&V.getSemantics() == &APFloat::IEEEsingle) 115 return ftostr((double)V.convertToFloat()); 116 return "<unknown format in ftostr>"; // error 117 } 118 119 static inline std::string LowercaseString(const std::string &S) { 120 std::string result(S); 121 for (unsigned i = 0; i < S.length(); ++i) 122 if (isupper(result[i])) 123 result[i] = char(tolower(result[i])); 124 return result; 125 } 126 127 static inline std::string UppercaseString(const std::string &S) { 128 std::string result(S); 129 for (unsigned i = 0; i < S.length(); ++i) 130 if (islower(result[i])) 131 result[i] = char(toupper(result[i])); 132 return result; 133 } 134 135 /// StrInStrNoCase - Portable version of strcasestr. Locates the first 136 /// occurrence of string 's1' in string 's2', ignoring case. Returns 137 /// the offset of s2 in s1 or npos if s2 cannot be found. 138 StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2); 139 140 /// getToken - This function extracts one token from source, ignoring any 141 /// leading characters that appear in the Delimiters string, and ending the 142 /// token at any of the characters that appear in the Delimiters string. If 143 /// there are no tokens in the source string, an empty string is returned. 144 /// The function returns a pair containing the extracted token and the 145 /// remaining tail string. 146 std::pair<StringRef, StringRef> getToken(StringRef Source, 147 StringRef Delimiters = " \t\n\v\f\r"); 148 149 /// SplitString - Split up the specified string according to the specified 150 /// delimiters, appending the result fragments to the output list. 151 void SplitString(StringRef Source, 152 SmallVectorImpl<StringRef> &OutFragments, 153 StringRef Delimiters = " \t\n\v\f\r"); 154 155 /// HashString - Hash function for strings. 156 /// 157 /// This is the Bernstein hash function. 158 // 159 // FIXME: Investigate whether a modified bernstein hash function performs 160 // better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx 161 // X*33+c -> X*33^c 162 static inline unsigned HashString(StringRef Str, unsigned Result = 0) { 163 for (unsigned i = 0, e = Str.size(); i != e; ++i) 164 Result = Result * 33 + Str[i]; 165 return Result; 166 } 167 168 } // End llvm namespace 169 170 #endif 171
