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/DenseMapInfo.h" 20 #include "llvm/ADT/StringRef.h" 21 #include <cctype> 22 #include <cstdio> 23 #include <string> 24 25 namespace llvm { 26 template<typename T> class SmallVectorImpl; 27 28 /// hexdigit - Return the hexadecimal character for the 29 /// given number \arg X (which should be less than 16). 30 static inline char hexdigit(unsigned X, bool LowerCase = false) { 31 const char HexChar = LowerCase ? 'a' : 'A'; 32 return X < 10 ? '0' + X : HexChar + X - 10; 33 } 34 35 /// utohex_buffer - Emit the specified number into the buffer specified by 36 /// BufferEnd, returning a pointer to the start of the string. This can be used 37 /// like this: (note that the buffer must be large enough to handle any number): 38 /// char Buffer[40]; 39 /// printf("0x%s", utohex_buffer(X, Buffer+40)); 40 /// 41 /// This should only be used with unsigned types. 42 /// 43 template<typename IntTy> 44 static inline char *utohex_buffer(IntTy X, char *BufferEnd) { 45 char *BufPtr = BufferEnd; 46 *--BufPtr = 0; // Null terminate buffer. 47 if (X == 0) { 48 *--BufPtr = '0'; // Handle special case. 49 return BufPtr; 50 } 51 52 while (X) { 53 unsigned char Mod = static_cast<unsigned char>(X) & 15; 54 *--BufPtr = hexdigit(Mod); 55 X >>= 4; 56 } 57 return BufPtr; 58 } 59 60 static inline std::string utohexstr(uint64_t X) { 61 char Buffer[17]; 62 return utohex_buffer(X, Buffer+17); 63 } 64 65 static inline std::string utostr_32(uint32_t X, bool isNeg = false) { 66 char Buffer[11]; 67 char *BufPtr = Buffer+11; 68 69 if (X == 0) *--BufPtr = '0'; // Handle special case... 70 71 while (X) { 72 *--BufPtr = '0' + char(X % 10); 73 X /= 10; 74 } 75 76 if (isNeg) *--BufPtr = '-'; // Add negative sign... 77 78 return std::string(BufPtr, Buffer+11); 79 } 80 81 static inline std::string utostr(uint64_t X, bool isNeg = false) { 82 char Buffer[21]; 83 char *BufPtr = Buffer+21; 84 85 if (X == 0) *--BufPtr = '0'; // Handle special case... 86 87 while (X) { 88 *--BufPtr = '0' + char(X % 10); 89 X /= 10; 90 } 91 92 if (isNeg) *--BufPtr = '-'; // Add negative sign... 93 return std::string(BufPtr, Buffer+21); 94 } 95 96 97 static inline std::string itostr(int64_t X) { 98 if (X < 0) 99 return utostr(static_cast<uint64_t>(-X), true); 100 else 101 return utostr(static_cast<uint64_t>(X)); 102 } 103 104 static inline std::string ftostr(double V) { 105 char Buffer[200]; 106 sprintf(Buffer, "%20.6e", V); 107 char *B = Buffer; 108 while (*B == ' ') ++B; 109 return B; 110 } 111 112 static inline std::string ftostr(const APFloat& V) { 113 if (&V.getSemantics() == &APFloat::IEEEdouble) 114 return ftostr(V.convertToDouble()); 115 else if (&V.getSemantics() == &APFloat::IEEEsingle) 116 return ftostr((double)V.convertToFloat()); 117 return "<unknown format in ftostr>"; // error 118 } 119 120 static inline std::string LowercaseString(const std::string &S) { 121 std::string result(S); 122 for (unsigned i = 0; i < S.length(); ++i) 123 if (isupper(result[i])) 124 result[i] = char(tolower(result[i])); 125 return result; 126 } 127 128 static inline std::string UppercaseString(const std::string &S) { 129 std::string result(S); 130 for (unsigned i = 0; i < S.length(); ++i) 131 if (islower(result[i])) 132 result[i] = char(toupper(result[i])); 133 return result; 134 } 135 136 /// StrInStrNoCase - Portable version of strcasestr. Locates the first 137 /// occurrence of string 's1' in string 's2', ignoring case. Returns 138 /// the offset of s2 in s1 or npos if s2 cannot be found. 139 StringRef::size_type StrInStrNoCase(StringRef s1, StringRef s2); 140 141 /// getToken - This function extracts one token from source, ignoring any 142 /// leading characters that appear in the Delimiters string, and ending the 143 /// token at any of the characters that appear in the Delimiters string. If 144 /// there are no tokens in the source string, an empty string is returned. 145 /// The function returns a pair containing the extracted token and the 146 /// remaining tail string. 147 std::pair<StringRef, StringRef> getToken(StringRef Source, 148 StringRef Delimiters = " \t\n\v\f\r"); 149 150 /// SplitString - Split up the specified string according to the specified 151 /// delimiters, appending the result fragments to the output list. 152 void SplitString(StringRef Source, 153 SmallVectorImpl<StringRef> &OutFragments, 154 StringRef Delimiters = " \t\n\v\f\r"); 155 156 /// HashString - Hash function for strings. 157 /// 158 /// This is the Bernstein hash function. 159 // 160 // FIXME: Investigate whether a modified bernstein hash function performs 161 // better: http://eternallyconfuzzled.com/tuts/algorithms/jsw_tut_hashing.aspx 162 // X*33+c -> X*33^c 163 static inline unsigned HashString(StringRef Str, unsigned Result = 0) { 164 for (unsigned i = 0, e = Str.size(); i != e; ++i) 165 Result = Result * 33 + Str[i]; 166 return Result; 167 } 168 169 } // End llvm namespace 170 171 #endif 172
