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| 1 #!/usr/bin/env python | |
| 2 # | |
| 3 # Copyright 2007 Neal Norwitz | |
| 4 # Portions Copyright 2007 Google Inc. | |
| 5 # | |
| 6 # Licensed under the Apache License, Version 2.0 (the "License"); | |
| 7 # you may not use this file except in compliance with the License. | |
| 8 # You may obtain a copy of the License at | |
| 9 # | |
| 10 # http://www.apache.org/licenses/LICENSE-2.0 | |
| 11 # | |
| 12 # Unless required by applicable law or agreed to in writing, software | |
| 13 # distributed under the License is distributed on an "AS IS" BASIS, | |
| 14 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| 15 # See the License for the specific language governing permissions and | |
| 16 # limitations under the License. | |
| 17 | |
| 18 """Tokenize C++ source code.""" | |
| 19 | |
| 20 __author__ = 'nnorwitz@google.com (Neal Norwitz)' | |
| 21 | |
| 22 | |
| 23 try: | |
| 24 # Python 3.x | |
| 25 import builtins | |
| 26 except ImportError: | |
| 27 # Python 2.x | |
| 28 import __builtin__ as builtins | |
| 29 | |
| 30 | |
| 31 import sys | |
| 32 | |
| 33 from cpp import utils | |
| 34 | |
| 35 | |
| 36 if not hasattr(builtins, 'set'): | |
| 37 # Nominal support for Python 2.3. | |
| 38 from sets import Set as set | |
| 39 | |
| 40 | |
| 41 # Add $ as a valid identifier char since so much code uses it. | |
| 42 _letters = 'abcdefghijklmnopqrstuvwxyz' | |
| 43 VALID_IDENTIFIER_CHARS = set(_letters + _letters.upper() + '_0123456789$') | |
| 44 HEX_DIGITS = set('0123456789abcdefABCDEF') | |
| 45 INT_OR_FLOAT_DIGITS = set('01234567890eE-+') | |
| 46 | |
| 47 | |
| 48 # C++0x string preffixes. | |
| 49 _STR_PREFIXES = set(('R', 'u8', 'u8R', 'u', 'uR', 'U', 'UR', 'L', 'LR')) | |
| 50 | |
| 51 | |
| 52 # Token types. | |
| 53 UNKNOWN = 'UNKNOWN' | |
| 54 SYNTAX = 'SYNTAX' | |
| 55 CONSTANT = 'CONSTANT' | |
| 56 NAME = 'NAME' | |
| 57 PREPROCESSOR = 'PREPROCESSOR' | |
| 58 | |
| 59 # Where the token originated from. This can be used for backtracking. | |
| 60 # It is always set to WHENCE_STREAM in this code. | |
| 61 WHENCE_STREAM, WHENCE_QUEUE = range(2) | |
| 62 | |
| 63 | |
| 64 class Token(object): | |
| 65 """Data container to represent a C++ token. | |
| 66 | |
| 67 Tokens can be identifiers, syntax char(s), constants, or | |
| 68 pre-processor directives. | |
| 69 | |
| 70 start contains the index of the first char of the token in the source | |
| 71 end contains the index of the last char of the token in the source | |
| 72 """ | |
| 73 | |
| 74 def __init__(self, token_type, name, start, end): | |
| 75 self.token_type = token_type | |
| 76 self.name = name | |
| 77 self.start = start | |
| 78 self.end = end | |
| 79 self.whence = WHENCE_STREAM | |
| 80 | |
| 81 def __str__(self): | |
| 82 if not utils.DEBUG: | |
| 83 return 'Token(%r)' % self.name | |
| 84 return 'Token(%r, %s, %s)' % (self.name, self.start, self.end) | |
| 85 | |
| 86 __repr__ = __str__ | |
| 87 | |
| 88 | |
| 89 def _GetString(source, start, i): | |
| 90 i = source.find('"', i+1) | |
| 91 while source[i-1] == '\\': | |
| 92 # Count the trailing backslashes. | |
| 93 backslash_count = 1 | |
| 94 j = i - 2 | |
| 95 while source[j] == '\\': | |
| 96 backslash_count += 1 | |
| 97 j -= 1 | |
| 98 # When trailing backslashes are even, they escape each other. | |
| 99 if (backslash_count % 2) == 0: | |
| 100 break | |
| 101 i = source.find('"', i+1) | |
| 102 return i + 1 | |
| 103 | |
| 104 | |
| 105 def _GetChar(source, start, i): | |
| 106 # NOTE(nnorwitz): may not be quite correct, should be good enough. | |
| 107 i = source.find("'", i+1) | |
| 108 while source[i-1] == '\\': | |
| 109 # Need to special case '\\'. | |
| 110 if (i - 2) > start and source[i-2] == '\\': | |
| 111 break | |
| 112 i = source.find("'", i+1) | |
| 113 # Try to handle unterminated single quotes (in a #if 0 block). | |
| 114 if i < 0: | |
| 115 i = start | |
| 116 return i + 1 | |
| 117 | |
| 118 | |
| 119 def GetTokens(source): | |
| 120 """Returns a sequence of Tokens. | |
| 121 | |
| 122 Args: | |
| 123 source: string of C++ source code. | |
| 124 | |
| 125 Yields: | |
| 126 Token that represents the next token in the source. | |
| 127 """ | |
| 128 # Cache various valid character sets for speed. | |
| 129 valid_identifier_chars = VALID_IDENTIFIER_CHARS | |
| 130 hex_digits = HEX_DIGITS | |
| 131 int_or_float_digits = INT_OR_FLOAT_DIGITS | |
| 132 int_or_float_digits2 = int_or_float_digits | set('.') | |
| 133 | |
| 134 # Only ignore errors while in a #if 0 block. | |
| 135 ignore_errors = False | |
| 136 count_ifs = 0 | |
| 137 | |
| 138 i = 0 | |
| 139 end = len(source) | |
| 140 while i < end: | |
| 141 # Skip whitespace. | |
| 142 while i < end and source[i].isspace(): | |
| 143 i += 1 | |
| 144 if i >= end: | |
| 145 return | |
| 146 | |
| 147 token_type = UNKNOWN | |
| 148 start = i | |
| 149 c = source[i] | |
| 150 if c.isalpha() or c == '_': # Find a string token. | |
| 151 token_type = NAME | |
| 152 while source[i] in valid_identifier_chars: | |
| 153 i += 1 | |
| 154 # String and character constants can look like a name if | |
| 155 # they are something like L"". | |
| 156 if (source[i] == "'" and (i - start) == 1 and | |
| 157 source[start:i] in 'uUL'): | |
| 158 # u, U, and L are valid C++0x character preffixes. | |
| 159 token_type = CONSTANT | |
| 160 i = _GetChar(source, start, i) | |
| 161 elif source[i] == "'" and source[start:i] in _STR_PREFIXES: | |
| 162 token_type = CONSTANT | |
| 163 i = _GetString(source, start, i) | |
| 164 elif c == '/' and source[i+1] == '/': # Find // comments. | |
| 165 i = source.find('\n', i) | |
| 166 if i == -1: # Handle EOF. | |
| 167 i = end | |
| 168 continue | |
| 169 elif c == '/' and source[i+1] == '*': # Find /* comments. */ | |
| 170 i = source.find('*/', i) + 2 | |
| 171 continue | |
| 172 elif c in ':+-<>&|*=': # : or :: (plus other chars). | |
| 173 token_type = SYNTAX | |
| 174 i += 1 | |
| 175 new_ch = source[i] | |
| 176 if new_ch == c: | |
| 177 i += 1 | |
| 178 elif c == '-' and new_ch == '>': | |
| 179 i += 1 | |
| 180 elif new_ch == '=': | |
| 181 i += 1 | |
| 182 elif c in '()[]{}~!?^%;/.,': # Handle single char tokens. | |
| 183 token_type = SYNTAX | |
| 184 i += 1 | |
| 185 if c == '.' and source[i].isdigit(): | |
| 186 token_type = CONSTANT | |
| 187 i += 1 | |
| 188 while source[i] in int_or_float_digits: | |
| 189 i += 1 | |
| 190 # Handle float suffixes. | |
| 191 for suffix in ('l', 'f'): | |
| 192 if suffix == source[i:i+1].lower(): | |
| 193 i += 1 | |
| 194 break | |
| 195 elif c.isdigit(): # Find integer. | |
| 196 token_type = CONSTANT | |
| 197 if c == '0' and source[i+1] in 'xX': | |
| 198 # Handle hex digits. | |
| 199 i += 2 | |
| 200 while source[i] in hex_digits: | |
| 201 i += 1 | |
| 202 else: | |
| 203 while source[i] in int_or_float_digits2: | |
| 204 i += 1 | |
| 205 # Handle integer (and float) suffixes. | |
| 206 for suffix in ('ull', 'll', 'ul', 'l', 'f', 'u'): | |
| 207 size = len(suffix) | |
| 208 if suffix == source[i:i+size].lower(): | |
| 209 i += size | |
| 210 break | |
| 211 elif c == '"': # Find string. | |
| 212 token_type = CONSTANT | |
| 213 i = _GetString(source, start, i) | |
| 214 elif c == "'": # Find char. | |
| 215 token_type = CONSTANT | |
| 216 i = _GetChar(source, start, i) | |
| 217 elif c == '#': # Find pre-processor command. | |
| 218 token_type = PREPROCESSOR | |
| 219 got_if = source[i:i+3] == '#if' and source[i+3:i+4].isspace() | |
| 220 if got_if: | |
| 221 count_ifs += 1 | |
| 222 elif source[i:i+6] == '#endif': | |
| 223 count_ifs -= 1 | |
| 224 if count_ifs == 0: | |
| 225 ignore_errors = False | |
| 226 | |
| 227 # TODO(nnorwitz): handle preprocessor statements (\ continuations). | |
| 228 while 1: | |
| 229 i1 = source.find('\n', i) | |
| 230 i2 = source.find('//', i) | |
| 231 i3 = source.find('/*', i) | |
| 232 i4 = source.find('"', i) | |
| 233 # NOTE(nnorwitz): doesn't handle comments in #define macros. | |
| 234 # Get the first important symbol (newline, comment, EOF/end). | |
| 235 i = min([x for x in (i1, i2, i3, i4, end) if x != -1]) | |
| 236 | |
| 237 # Handle #include "dir//foo.h" properly. | |
| 238 if source[i] == '"': | |
| 239 i = source.find('"', i+1) + 1 | |
| 240 assert i > 0 | |
| 241 continue | |
| 242 # Keep going if end of the line and the line ends with \. | |
| 243 if not (i == i1 and source[i-1] == '\\'): | |
| 244 if got_if: | |
| 245 condition = source[start+4:i].lstrip() | |
| 246 if (condition.startswith('0') or | |
| 247 condition.startswith('(0)')): | |
| 248 ignore_errors = True | |
| 249 break | |
| 250 i += 1 | |
| 251 elif c == '\\': # Handle \ in code. | |
| 252 # This is different from the pre-processor \ handling. | |
| 253 i += 1 | |
| 254 continue | |
| 255 elif ignore_errors: | |
| 256 # The tokenizer seems to be in pretty good shape. This | |
| 257 # raise is conditionally disabled so that bogus code | |
| 258 # in an #if 0 block can be handled. Since we will ignore | |
| 259 # it anyways, this is probably fine. So disable the | |
| 260 # exception and return the bogus char. | |
| 261 i += 1 | |
| 262 else: | |
| 263 sys.stderr.write('Got invalid token in %s @ %d token:%s: %r\n' % | |
| 264 ('?', i, c, source[i-10:i+10])) | |
| 265 raise RuntimeError('unexpected token') | |
| 266 | |
| 267 if i <= 0: | |
| 268 print('Invalid index, exiting now.') | |
| 269 return | |
| 270 yield Token(token_type, source[start:i], start, i) | |
| 271 | |
| 272 | |
| 273 if __name__ == '__main__': | |
| 274 def main(argv): | |
| 275 """Driver mostly for testing purposes.""" | |
| 276 for filename in argv[1:]: | |
| 277 source = utils.ReadFile(filename) | |
| 278 if source is None: | |
| 279 continue | |
| 280 | |
| 281 for token in GetTokens(source): | |
| 282 print('%-12s: %s' % (token.token_type, token.name)) | |
| 283 # print('\r%6.2f%%' % (100.0 * index / token.end),) | |
| 284 sys.stdout.write('\n') | |
| 285 | |
| 286 | |
| 287 main(sys.argv) | |
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Chromium Code Reviews
Issue 624713003:
Keep only base/extractor.[cc|h]. (Closed)
Base URL: https://chromium.googlesource.com/external/omaha.git@master