| #!/usr/bin/env python | |
| # | |
| # Copyright 2007 Neal Norwitz | |
| # Portions Copyright 2007 Google Inc. | |
| # | |
| # Licensed under the Apache License, Version 2.0 (the "License"); | |
| # you may not use this file except in compliance with the License. | |
| # You may obtain a copy of the License at | |
| # | |
| # http://www.apache.org/licenses/LICENSE-2.0 | |
| # | |
| # Unless required by applicable law or agreed to in writing, software | |
| # distributed under the License is distributed on an "AS IS" BASIS, | |
| # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
| # See the License for the specific language governing permissions and | |
| # limitations under the License. | |
| """Tokenize C++ source code.""" | |
| __author__ = 'nnorwitz@google.com (Neal Norwitz)' | |
| try: | |
| # Python 3.x | |
| import builtins | |
| except ImportError: | |
| # Python 2.x | |
| import __builtin__ as builtins | |
| import sys | |
| from cpp import utils | |
| if not hasattr(builtins, 'set'): | |
| # Nominal support for Python 2.3. | |
| from sets import Set as set | |
| # Add $ as a valid identifier char since so much code uses it. | |
| _letters = 'abcdefghijklmnopqrstuvwxyz' | |
| VALID_IDENTIFIER_CHARS = set(_letters + _letters.upper() + '_0123456789$') | |
| HEX_DIGITS = set('0123456789abcdefABCDEF') | |
| INT_OR_FLOAT_DIGITS = set('01234567890eE-+') | |
| # C++0x string preffixes. | |
| _STR_PREFIXES = set(('R', 'u8', 'u8R', 'u', 'uR', 'U', 'UR', 'L', 'LR')) | |
| # Token types. | |
| UNKNOWN = 'UNKNOWN' | |
| SYNTAX = 'SYNTAX' | |
| CONSTANT = 'CONSTANT' | |
| NAME = 'NAME' | |
| PREPROCESSOR = 'PREPROCESSOR' | |
| # Where the token originated from. This can be used for backtracking. | |
| # It is always set to WHENCE_STREAM in this code. | |
| WHENCE_STREAM, WHENCE_QUEUE = range(2) | |
| class Token(object): | |
| """Data container to represent a C++ token. | |
| Tokens can be identifiers, syntax char(s), constants, or | |
| pre-processor directives. | |
| start contains the index of the first char of the token in the source | |
| end contains the index of the last char of the token in the source | |
| """ | |
| def __init__(self, token_type, name, start, end): | |
| self.token_type = token_type | |
| self.name = name | |
| self.start = start | |
| self.end = end | |
| self.whence = WHENCE_STREAM | |
| def __str__(self): | |
| if not utils.DEBUG: | |
| return 'Token(%r)' % self.name | |
| return 'Token(%r, %s, %s)' % (self.name, self.start, self.end) | |
| __repr__ = __str__ | |
| def _GetString(source, start, i): | |
| i = source.find('"', i+1) | |
| while source[i-1] == '\\': | |
| # Count the trailing backslashes. | |
| backslash_count = 1 | |
| j = i - 2 | |
| while source[j] == '\\': | |
| backslash_count += 1 | |
| j -= 1 | |
| # When trailing backslashes are even, they escape each other. | |
| if (backslash_count % 2) == 0: | |
| break | |
| i = source.find('"', i+1) | |
| return i + 1 | |
| def _GetChar(source, start, i): | |
| # NOTE(nnorwitz): may not be quite correct, should be good enough. | |
| i = source.find("'", i+1) | |
| while source[i-1] == '\\': | |
| # Need to special case '\\'. | |
| if (i - 2) > start and source[i-2] == '\\': | |
| break | |
| i = source.find("'", i+1) | |
| # Try to handle unterminated single quotes (in a #if 0 block). | |
| if i < 0: | |
| i = start | |
| return i + 1 | |
| def GetTokens(source): | |
| """Returns a sequence of Tokens. | |
| Args: | |
| source: string of C++ source code. | |
| Yields: | |
| Token that represents the next token in the source. | |
| """ | |
| # Cache various valid character sets for speed. | |
| valid_identifier_chars = VALID_IDENTIFIER_CHARS | |
| hex_digits = HEX_DIGITS | |
| int_or_float_digits = INT_OR_FLOAT_DIGITS | |
| int_or_float_digits2 = int_or_float_digits | set('.') | |
| # Only ignore errors while in a #if 0 block. | |
| ignore_errors = False | |
| count_ifs = 0 | |
| i = 0 | |
| end = len(source) | |
| while i < end: | |
| # Skip whitespace. | |
| while i < end and source[i].isspace(): | |
| i += 1 | |
| if i >= end: | |
| return | |
| token_type = UNKNOWN | |
| start = i | |
| c = source[i] | |
| if c.isalpha() or c == '_': # Find a string token. | |
| token_type = NAME | |
| while source[i] in valid_identifier_chars: | |
| i += 1 | |
| # String and character constants can look like a name if | |
| # they are something like L"". | |
| if (source[i] == "'" and (i - start) == 1 and | |
| source[start:i] in 'uUL'): | |
| # u, U, and L are valid C++0x character preffixes. | |
| token_type = CONSTANT | |
| i = _GetChar(source, start, i) | |
| elif source[i] == "'" and source[start:i] in _STR_PREFIXES: | |
| token_type = CONSTANT | |
| i = _GetString(source, start, i) | |
| elif c == '/' and source[i+1] == '/': # Find // comments. | |
| i = source.find('\n', i) | |
| if i == -1: # Handle EOF. | |
| i = end | |
| continue | |
| elif c == '/' and source[i+1] == '*': # Find /* comments. */ | |
| i = source.find('*/', i) + 2 | |
| continue | |
| elif c in ':+-<>&|*=': # : or :: (plus other chars). | |
| token_type = SYNTAX | |
| i += 1 | |
| new_ch = source[i] | |
| if new_ch == c and c != '>': # Treat ">>" as two tokens. | |
| i += 1 | |
| elif c == '-' and new_ch == '>': | |
| i += 1 | |
| elif new_ch == '=': | |
| i += 1 | |
| elif c in '()[]{}~!?^%;/.,': # Handle single char tokens. | |
| token_type = SYNTAX | |
| i += 1 | |
| if c == '.' and source[i].isdigit(): | |
| token_type = CONSTANT | |
| i += 1 | |
| while source[i] in int_or_float_digits: | |
| i += 1 | |
| # Handle float suffixes. | |
| for suffix in ('l', 'f'): | |
| if suffix == source[i:i+1].lower(): | |
| i += 1 | |
| break | |
| elif c.isdigit(): # Find integer. | |
| token_type = CONSTANT | |
| if c == '0' and source[i+1] in 'xX': | |
| # Handle hex digits. | |
| i += 2 | |
| while source[i] in hex_digits: | |
| i += 1 | |
| else: | |
| while source[i] in int_or_float_digits2: | |
| i += 1 | |
| # Handle integer (and float) suffixes. | |
| for suffix in ('ull', 'll', 'ul', 'l', 'f', 'u'): | |
| size = len(suffix) | |
| if suffix == source[i:i+size].lower(): | |
| i += size | |
| break | |
| elif c == '"': # Find string. | |
| token_type = CONSTANT | |
| i = _GetString(source, start, i) | |
| elif c == "'": # Find char. | |
| token_type = CONSTANT | |
| i = _GetChar(source, start, i) | |
| elif c == '#': # Find pre-processor command. | |
| token_type = PREPROCESSOR | |
| got_if = source[i:i+3] == '#if' and source[i+3:i+4].isspace() | |
| if got_if: | |
| count_ifs += 1 | |
| elif source[i:i+6] == '#endif': | |
| count_ifs -= 1 | |
| if count_ifs == 0: | |
| ignore_errors = False | |
| # TODO(nnorwitz): handle preprocessor statements (\ continuations). | |
| while 1: | |
| i1 = source.find('\n', i) | |
| i2 = source.find('//', i) | |
| i3 = source.find('/*', i) | |
| i4 = source.find('"', i) | |
| # NOTE(nnorwitz): doesn't handle comments in #define macros. | |
| # Get the first important symbol (newline, comment, EOF/end). | |
| i = min([x for x in (i1, i2, i3, i4, end) if x != -1]) | |
| # Handle #include "dir//foo.h" properly. | |
| if source[i] == '"': | |
| i = source.find('"', i+1) + 1 | |
| assert i > 0 | |
| continue | |
| # Keep going if end of the line and the line ends with \. | |
| if not (i == i1 and source[i-1] == '\\'): | |
| if got_if: | |
| condition = source[start+4:i].lstrip() | |
| if (condition.startswith('0') or | |
| condition.startswith('(0)')): | |
| ignore_errors = True | |
| break | |
| i += 1 | |
| elif c == '\\': # Handle \ in code. | |
| # This is different from the pre-processor \ handling. | |
| i += 1 | |
| continue | |
| elif ignore_errors: | |
| # The tokenizer seems to be in pretty good shape. This | |
| # raise is conditionally disabled so that bogus code | |
| # in an #if 0 block can be handled. Since we will ignore | |
| # it anyways, this is probably fine. So disable the | |
| # exception and return the bogus char. | |
| i += 1 | |
| else: | |
| sys.stderr.write('Got invalid token in %s @ %d token:%s: %r\n' % | |
| ('?', i, c, source[i-10:i+10])) | |
| raise RuntimeError('unexpected token') | |
| if i <= 0: | |
| print('Invalid index, exiting now.') | |
| return | |
| yield Token(token_type, source[start:i], start, i) | |
| if __name__ == '__main__': | |
| def main(argv): | |
| """Driver mostly for testing purposes.""" | |
| for filename in argv[1:]: | |
| source = utils.ReadFile(filename) | |
| if source is None: | |
| continue | |
| for token in GetTokens(source): | |
| print('%-12s: %s' % (token.token_type, token.name)) | |
| # print('\r%6.2f%%' % (100.0 * index / token.end),) | |
| sys.stdout.write('\n') | |
| main(sys.argv) |