1 //===--- clang/Basic/CharInfo.h - Classifying ASCII Characters --*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLVM_CLANG_BASIC_CHARINFO_H 10 #define LLVM_CLANG_BASIC_CHARINFO_H 11 12 #include "clang/Basic/LLVM.h" 13 #include "llvm/ADT/StringRef.h" 14 #include "llvm/Support/Compiler.h" 15 #include "llvm/Support/DataTypes.h" 16 17 namespace clang { 18 namespace charinfo { 19 extern const uint16_t InfoTable[256]; 20 21 enum { 22 CHAR_HORZ_WS = 0x0001, // '\t', '\f', '\v'. Note, no '\0' 23 CHAR_VERT_WS = 0x0002, // '\r', '\n' 24 CHAR_SPACE = 0x0004, // ' ' 25 CHAR_DIGIT = 0x0008, // 0-9 26 CHAR_XLETTER = 0x0010, // a-f,A-F 27 CHAR_UPPER = 0x0020, // A-Z 28 CHAR_LOWER = 0x0040, // a-z 29 CHAR_UNDER = 0x0080, // _ 30 CHAR_PERIOD = 0x0100, // . 31 CHAR_RAWDEL = 0x0200, // {}[]#<>%:;?*+-/^&|~!=,"' 32 CHAR_PUNCT = 0x0400 // `$@() 33 }; 34 35 enum { 36 CHAR_XUPPER = CHAR_XLETTER | CHAR_UPPER, 37 CHAR_XLOWER = CHAR_XLETTER | CHAR_LOWER 38 }; 39 } // end namespace charinfo 40 41 /// Returns true if this is an ASCII character. 42 LLVM_READNONE inline bool isASCII(char c) { 43 return static_cast<unsigned char>(c) <= 127; 44 } 45 46 /// Returns true if this is a valid first character of a C identifier, 47 /// which is [a-zA-Z_]. 48 LLVM_READONLY inline bool isIdentifierHead(unsigned char c, 49 bool AllowDollar = false) { 50 using namespace charinfo; 51 if (InfoTable[c] & (CHAR_UPPER|CHAR_LOWER|CHAR_UNDER)) 52 return true; 53 return AllowDollar && c == '$'; 54 } 55 56 /// Returns true if this is a body character of a C identifier, 57 /// which is [a-zA-Z0-9_]. 58 LLVM_READONLY inline bool isIdentifierBody(unsigned char c, 59 bool AllowDollar = false) { 60 using namespace charinfo; 61 if (InfoTable[c] & (CHAR_UPPER|CHAR_LOWER|CHAR_DIGIT|CHAR_UNDER)) 62 return true; 63 return AllowDollar && c == '$'; 64 } 65 66 /// Returns true if this character is horizontal ASCII whitespace: 67 /// ' ', '\\t', '\\f', '\\v'. 68 /// 69 /// Note that this returns false for '\\0'. 70 LLVM_READONLY inline bool isHorizontalWhitespace(unsigned char c) { 71 using namespace charinfo; 72 return (InfoTable[c] & (CHAR_HORZ_WS|CHAR_SPACE)) != 0; 73 } 74 75 /// Returns true if this character is vertical ASCII whitespace: '\\n', '\\r'. 76 /// 77 /// Note that this returns false for '\\0'. 78 LLVM_READONLY inline bool isVerticalWhitespace(unsigned char c) { 79 using namespace charinfo; 80 return (InfoTable[c] & CHAR_VERT_WS) != 0; 81 } 82 83 /// Return true if this character is horizontal or vertical ASCII whitespace: 84 /// ' ', '\\t', '\\f', '\\v', '\\n', '\\r'. 85 /// 86 /// Note that this returns false for '\\0'. 87 LLVM_READONLY inline bool isWhitespace(unsigned char c) { 88 using namespace charinfo; 89 return (InfoTable[c] & (CHAR_HORZ_WS|CHAR_VERT_WS|CHAR_SPACE)) != 0; 90 } 91 92 /// Return true if this character is an ASCII digit: [0-9] 93 LLVM_READONLY inline bool isDigit(unsigned char c) { 94 using namespace charinfo; 95 return (InfoTable[c] & CHAR_DIGIT) != 0; 96 } 97 98 /// Return true if this character is a lowercase ASCII letter: [a-z] 99 LLVM_READONLY inline bool isLowercase(unsigned char c) { 100 using namespace charinfo; 101 return (InfoTable[c] & CHAR_LOWER) != 0; 102 } 103 104 /// Return true if this character is an uppercase ASCII letter: [A-Z] 105 LLVM_READONLY inline bool isUppercase(unsigned char c) { 106 using namespace charinfo; 107 return (InfoTable[c] & CHAR_UPPER) != 0; 108 } 109 110 /// Return true if this character is an ASCII letter: [a-zA-Z] 111 LLVM_READONLY inline bool isLetter(unsigned char c) { 112 using namespace charinfo; 113 return (InfoTable[c] & (CHAR_UPPER|CHAR_LOWER)) != 0; 114 } 115 116 /// Return true if this character is an ASCII letter or digit: [a-zA-Z0-9] 117 LLVM_READONLY inline bool isAlphanumeric(unsigned char c) { 118 using namespace charinfo; 119 return (InfoTable[c] & (CHAR_DIGIT|CHAR_UPPER|CHAR_LOWER)) != 0; 120 } 121 122 /// Return true if this character is an ASCII hex digit: [0-9a-fA-F] 123 LLVM_READONLY inline bool isHexDigit(unsigned char c) { 124 using namespace charinfo; 125 return (InfoTable[c] & (CHAR_DIGIT|CHAR_XLETTER)) != 0; 126 } 127 128 /// Return true if this character is an ASCII punctuation character. 129 /// 130 /// Note that '_' is both a punctuation character and an identifier character! 131 LLVM_READONLY inline bool isPunctuation(unsigned char c) { 132 using namespace charinfo; 133 return (InfoTable[c] & (CHAR_UNDER|CHAR_PERIOD|CHAR_RAWDEL|CHAR_PUNCT)) != 0; 134 } 135 136 /// Return true if this character is an ASCII printable character; that is, a 137 /// character that should take exactly one column to print in a fixed-width 138 /// terminal. 139 LLVM_READONLY inline bool isPrintable(unsigned char c) { 140 using namespace charinfo; 141 return (InfoTable[c] & (CHAR_UPPER|CHAR_LOWER|CHAR_PERIOD|CHAR_PUNCT| 142 CHAR_DIGIT|CHAR_UNDER|CHAR_RAWDEL|CHAR_SPACE)) != 0; 143 } 144 145 /// Return true if this is the body character of a C preprocessing number, 146 /// which is [a-zA-Z0-9_.]. 147 LLVM_READONLY inline bool isPreprocessingNumberBody(unsigned char c) { 148 using namespace charinfo; 149 return (InfoTable[c] & 150 (CHAR_UPPER|CHAR_LOWER|CHAR_DIGIT|CHAR_UNDER|CHAR_PERIOD)) != 0; 151 } 152 153 /// Return true if this is the body character of a C++ raw string delimiter. 154 LLVM_READONLY inline bool isRawStringDelimBody(unsigned char c) { 155 using namespace charinfo; 156 return (InfoTable[c] & (CHAR_UPPER|CHAR_LOWER|CHAR_PERIOD| 157 CHAR_DIGIT|CHAR_UNDER|CHAR_RAWDEL)) != 0; 158 } 159 160 161 /// Converts the given ASCII character to its lowercase equivalent. 162 /// 163 /// If the character is not an uppercase character, it is returned as is. 164 LLVM_READONLY inline char toLowercase(char c) { 165 if (isUppercase(c)) 166 return c + 'a' - 'A'; 167 return c; 168 } 169 170 /// Converts the given ASCII character to its uppercase equivalent. 171 /// 172 /// If the character is not a lowercase character, it is returned as is. 173 LLVM_READONLY inline char toUppercase(char c) { 174 if (isLowercase(c)) 175 return c + 'A' - 'a'; 176 return c; 177 } 178 179 180 /// Return true if this is a valid ASCII identifier. 181 /// 182 /// Note that this is a very simple check; it does not accept UCNs as valid 183 /// identifier characters. 184 LLVM_READONLY inline bool isValidIdentifier(StringRef S, 185 bool AllowDollar = false) { 186 if (S.empty() || !isIdentifierHead(S[0], AllowDollar)) 187 return false; 188 189 for (StringRef::iterator I = S.begin(), E = S.end(); I != E; ++I) 190 if (!isIdentifierBody(*I, AllowDollar)) 191 return false; 192 193 return true; 194 } 195 196 } // end namespace clang 197 198 #endif 199