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| 1 # Copyright (C) 2013 Google Inc. All rights reserved. |
| 2 # |
| 3 # Redistribution and use in source and binary forms, with or without |
| 4 # modification, are permitted provided that the following conditions are |
| 5 # met: |
| 6 # |
| 7 # * Redistributions of source code must retain the above copyright |
| 8 # notice, this list of conditions and the following disclaimer. |
| 9 # * Redistributions in binary form must reproduce the above |
| 10 # copyright notice, this list of conditions and the following disclaimer |
| 11 # in the documentation and/or other materials provided with the |
| 12 # distribution. |
| 13 # * Neither the name of Google Inc. nor the names of its |
| 14 # contributors may be used to endorse or promote products derived from |
| 15 # this software without specific prior written permission. |
| 16 # |
| 17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| 18 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| 19 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| 20 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| 21 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 22 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| 23 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 24 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 25 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 26 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| 27 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 28 |
| 29 """Lexer for Blink IDL. |
| 30 |
| 31 The lexer uses the PLY (Python Lex-Yacc) library to build a tokenizer which |
| 32 understands the Blink dialect of Web IDL and produces a token stream suitable |
| 33 for the Blink IDL parser. |
| 34 |
| 35 Blink IDL is identical to Web IDL at the token level, but the base lexer |
| 36 does not discard comments. We need to override (and not include comments in |
| 37 the token stream), as otherwise comments must be explicitly included in the |
| 38 phrase grammar of the parser. |
| 39 |
| 40 FIXME: Change base lexer to discard comments, and simply used the base |
| 41 lexer, eliminating this separate lexer. |
| 42 |
| 43 Web IDL: |
| 44 http://www.w3.org/TR/WebIDL/ |
| 45 Web IDL Grammar: |
| 46 http://www.w3.org/TR/WebIDL/#idl-grammar |
| 47 PLY: |
| 48 http://www.dabeaz.com/ply/ |
| 49 |
| 50 Design doc: |
| 51 http://www.chromium.org/developers/design-documents/idl-compiler#TOC-Front-end |
| 52 """ |
| 53 |
| 54 # Disable attribute validation, as lint can't import parent class to check |
| 55 # pylint: disable=E1101 |
| 56 |
| 57 import os.path |
| 58 import sys |
| 59 |
| 60 # PLY is in Chromium src/third_party/ply |
| 61 module_path, module_name = os.path.split(__file__) |
| 62 third_party = os.path.join(module_path, os.pardir, os.pardir, os.pardir, os.pard
ir) |
| 63 # Insert at front to override system libraries, and after path[0] == script dir |
| 64 sys.path.insert(1, third_party) |
| 65 from ply import lex |
| 66 |
| 67 # Base lexer is in Chromium src/tools/idl_parser |
| 68 tools_dir = os.path.join(third_party, os.pardir, 'tools') |
| 69 sys.path.append(tools_dir) |
| 70 from idl_parser.idl_lexer import IDLLexer |
| 71 |
| 72 REMOVE_TOKENS = ['COMMENT'] |
| 73 |
| 74 |
| 75 class BlinkIDLLexer(IDLLexer): |
| 76 # ignore comments |
| 77 def t_COMMENT(self, t): |
| 78 r'(/\*(.|\n)*?\*/)|(//.*(\n[ \t]*//.*)*)' |
| 79 self.AddLines(t.value.count('\n')) |
| 80 |
| 81 # Analogs to _AddToken/_AddTokens in base lexer |
| 82 # Needed to remove COMMENT token, since comments ignored |
| 83 def _RemoveToken(self, token): |
| 84 if token in self.tokens: |
| 85 self.tokens.remove(token) |
| 86 |
| 87 def _RemoveTokens(self, tokens): |
| 88 for token in tokens: |
| 89 self._RemoveToken(token) |
| 90 |
| 91 def __init__(self, debug=False, optimize=True, outputdir=None): |
| 92 if debug: |
| 93 # Turn off optimization and caching to help debugging |
| 94 optimize = False |
| 95 outputdir = None |
| 96 if outputdir: |
| 97 # Need outputdir in path because lex imports the cached lex table |
| 98 # as a Python module |
| 99 sys.path.append(outputdir) |
| 100 |
| 101 IDLLexer.__init__(self) |
| 102 # Overrides to parent class |
| 103 self._RemoveTokens(REMOVE_TOKENS) |
| 104 # Optimized mode substantially decreases startup time (by disabling |
| 105 # error checking), and also allows use of Python's optimized mode. |
| 106 # See: Optimized Mode |
| 107 # http://www.dabeaz.com/ply/ply.html#ply_nn15 |
| 108 self._lexobj = lex.lex(object=self, |
| 109 debug=debug, |
| 110 optimize=optimize, |
| 111 outputdir=outputdir) |
| 112 |
| 113 |
| 114 ################################################################################ |
| 115 |
| 116 def main(argv): |
| 117 # If file itself executed, build and cache lex table |
| 118 try: |
| 119 outputdir = argv[1] |
| 120 except IndexError as err: |
| 121 print 'Usage: %s OUTPUT_DIR' % argv[0] |
| 122 return 1 |
| 123 lexer = BlinkIDLLexer(outputdir=outputdir) |
| 124 |
| 125 |
| 126 if __name__ == '__main__': |
| 127 sys.exit(main(sys.argv)) |
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