IDL compiler: delete Perl compiler, remove unstable/ directory

Source/bindings/scripts/unstable/blink_idl_parser.py

-# Copyright (C) 2013 Google Inc. All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-"""Parser for Blink IDL.
-
-The parser uses the PLY (Python Lex-Yacc) library to build a set of parsing
-rules which understand the Blink dialect of Web IDL.
-It derives from a standard Web IDL parser, overriding rules where Blink IDL
-differs syntactically or semantically from the base parser, or where the base
-parser diverges from the Web IDL standard.
-
-Web IDL:
-    http://www.w3.org/TR/WebIDL/
-Web IDL Grammar:
-    http://www.w3.org/TR/WebIDL/#idl-grammar
-PLY:
-    http://www.dabeaz.com/ply/
-"""
-
-# Disable check for line length and Member as Function due to how grammar rules
-# are defined with PLY
-#
-# pylint: disable=R0201
-# pylint: disable=C0301
-#
-# Disable attribute validation, as lint can't import parent class to check
-# pylint: disable=E1101
-
-import os.path
-import sys
-
-# PLY is in Chromium src/third_party/ply
-module_path, module_name = os.path.split(__file__)
-third_party = os.path.join(module_path, os.pardir, os.pardir, os.pardir, os.pardir, os.pardir)
-# Insert at front to override system libraries, and after path[0] == script dir
-sys.path.insert(1, third_party)
-from ply import yacc
-
-# Base parser is in Chromium src/tools/idl_parser
-tools_dir = os.path.join(module_path, os.pardir, os.pardir, os.pardir, os.pardir, os.pardir, os.pardir, 'tools')
-sys.path.append(tools_dir)
-from idl_parser.idl_parser import IDLParser, ListFromConcat
-from idl_parser.idl_parser import ParseFile as parse_file
-
-from blink_idl_lexer import BlinkIDLLexer
-
-
-# Explicitly set starting symbol to rule defined only in base parser.
-# BEWARE that the starting symbol should NOT be defined in both the base parser
-# and the derived one, as otherwise which is used depends on which line number
-# is lower, which is fragile. Instead, either use one in base parser or
-# create a new symbol, so that this is unambiguous.
-# FIXME: unfortunately, this doesn't work in PLY 3.4, so need to duplicate the
-# rule below.
-STARTING_SYMBOL = 'Definitions'
-
-# We ignore comments (and hence don't need 'Top') but base parser preserves them
-# FIXME: Upstream: comments should be removed in base parser
-REMOVED_RULES = ['Top',  # [0]
-                 'Comments',  # [0.1]
-                 'CommentsRest',  # [0.2]
-                ]
-
-
-class BlinkIDLParser(IDLParser):
-    # [1]
-    # FIXME: Need to duplicate rule for starting symbol here, with line number
-    # *lower* than in the base parser (idl_parser.py).
-    # This is a bug in PLY: it determines starting symbol by lowest line number.
-    # This can be overridden by the 'start' parameter, but as of PLY 3.4 this
-    # doesn't work correctly.
-    def p_Definitions(self, p):
-        """Definitions : ExtendedAttributeList Definition Definitions
-                       | """
-        if len(p) > 1:
-            p[2].AddChildren(p[1])
-            p[0] = ListFromConcat(p[2], p[3])
-
-    # Below are grammar rules used by yacc, given by functions named p_<RULE>.
-    # * The docstring is the production rule in BNF (grammar).
-    # * The body is the yacc action (semantics).
-    #
-    # The PLY framework builds the actual low-level parser by introspecting this
-    # parser object, selecting all attributes named p_<RULE> as grammar rules.
-    # It extracts the docstrings and uses them as the production rules, building
-    # the table of a LALR parser, and uses the body of the functions as actions.
-    #
-    # Reference:
-    # http://www.dabeaz.com/ply/ply.html#ply_nn23
-    #
-    # Review of yacc:
-    # Yacc parses a token stream, internally producing a Concrete Syntax Tree
-    # (CST), where each node corresponds to a production rule in the grammar.
-    # At each node, it runs an action, which is usually "produce a node in the
-    # Abstract Syntax Tree (AST)" or "ignore this node" (for nodes in the CST
-    # that aren't included in the AST, since only needed for parsing).
-    #
-    # The rules use pseudo-variables; in PLY syntax:
-    # p[0] is the left side: assign return value to p[0] instead of returning,
-    # p[1] ... p[n] are the right side: the values can be accessed, and they
-    # can be modified.
-    # (In yacc these are $$ and $1 ... $n.)
-    #
-    # The rules can look cryptic at first, but there are a few standard
-    # transforms from the CST to AST. With these in mind, the actions should
-    # be reasonably legible.
-    #
-    # * Ignore production
-    #   Discard this branch. Primarily used when one alternative is empty.
-    #
-    #   Sample code:
-    #   if len(p) > 1:
-    #       p[0] = ...
-    #   # Note no assignment if len(p) == 1
-    #
-    # * Eliminate singleton production
-    #   Discard this node in the CST, pass the next level down up the tree.
-    #   Used to ignore productions only necessary for parsing, but not needed
-    #   in the AST.
-    #
-    #   Sample code:
-    #   p[0] = p[1]
-    #
-    # * Build node
-    #   The key type of rule. In this parser, produces object of class IDLNode.
-    #   There are several helper functions:
-    #   * BuildProduction: actually builds an IDLNode, based on a production.
-    #   * BuildAttribute: builds an IDLAttribute, which is a temporary
-    #                     object to hold a name-value pair, which is then
-    #                     set as a Property of the IDLNode when the IDLNode
-    #                     is built.
-    #   * BuildNamed: Same as BuildProduction, and sets the 'NAME' property.
-    #   * BuildTrue: BuildAttribute with value True, for flags.
-    #   See base idl_parser.py for definitions and more examples of use.
-    #
-    #   Sample code:
-    #   # Build node of type NodeType, with value p[1], and children.
-    #   p[0] = self.BuildProduction('NodeType', p, 1, children)
-    #
-    #   # Build named node of type NodeType, with name and value p[1].
-    #   # (children optional)
-    #   p[0] = self.BuildNamed('NodeType', p, 1)
-    #
-    #   # Make a list
-    #   # Used if one node has several children.
-    #   children = ListFromConcat(p[2], p[3])
-    #   p[0] = self.BuildProduction('NodeType', p, 1, children)
-    #
-    #   # Also used to collapse the right-associative tree
-    #   # produced by parsing a list back into a single list.
-    #   """Foos : Foo Foos
-    #           |"""
-    #   if len(p) > 1:
-    #       p[0] = ListFromConcat(p[1], p[2])
-    #
-    #   # Add children.
-    #   # Primarily used to add attributes, produced via BuildTrue.
-    #   # p_StaticAttribute
-    #   """StaticAttribute : STATIC Attribute"""
-    #   p[2].AddChildren(self.BuildTrue('STATIC'))
-    #   p[0] = p[2]
-    #
-    # Numbering scheme for the rules is:
-    # [1] for Web IDL spec (or additions in base parser)
-    #     These should all be upstreamed to the base parser.
-    # [b1] for Blink IDL changes (overrides Web IDL)
-    # [b1.1] for Blink IDL additions, auxiliary rules for [b1]
-    # Numbers are as per Candidate Recommendation 19 April 2012:
-    # http://www.w3.org/TR/2012/CR-WebIDL-20120419/
-
-    # [3] Override action, since we distinguish callbacks
-    # FIXME: Upstream
-    def p_CallbackOrInterface(self, p):
-        """CallbackOrInterface : CALLBACK CallbackRestOrInterface
-                               | Interface"""
-        if len(p) > 2:
-            p[2].AddChildren(self.BuildTrue('CALLBACK'))
-            p[0] = p[2]
-        else:
-            p[0] = p[1]
-
-    # [b27] Add strings, more 'Literal' productions
-    # 'Literal's needed because integers and strings are both internally strings
-    def p_ConstValue(self, p):
-        """ConstValue : BooleanLiteral
-                      | FloatLiteral
-                      | IntegerLiteral
-                      | StringLiteral
-                      | null"""
-        # Standard is (no 'string', fewer 'Literal's):
-        # ConstValue : BooleanLiteral
-        #            | FloatLiteral
-        #            | integer
-        #            | NULL
-        p[0] = p[1]
-
-    # [b27.1]
-    def p_IntegerLiteral(self, p):
-        """IntegerLiteral : integer"""
-        p[0] = ListFromConcat(self.BuildAttribute('TYPE', 'integer'),
-                              self.BuildAttribute('NAME', p[1]))
-
-    # [b27.2]
-    def p_StringLiteral(self, p):
-        """StringLiteral : string"""
-        p[0] = ListFromConcat(self.BuildAttribute('TYPE', 'DOMString'),
-                              self.BuildAttribute('NAME', p[1]))
-
-    # [b30] Add StaticAttribute
-    def p_AttributeOrOperation(self, p):
-        """AttributeOrOperation : STRINGIFIER StringifierAttributeOrOperation
-                                | Attribute
-                                | StaticAttribute
-                                | Operation"""
-        # Standard is (no StaticAttribute):
-        # AttributeOrOperation : STRINGIFIER StringifierAttributeOrOperation
-        #                      | Attribute
-        #                      | Operation
-        if len(p) > 2:
-            # FIXME: Clearer to add stringifier property here, as:
-            # p[2].AddChildren(self.BuildTrue('STRINGIFIER'))
-            # Fix when actually implementing stringifiers.
-            p[0] = p[2]
-        else:
-            p[0] = p[1]
-
-    # [b30.1]
-    def p_StaticAttribute(self, p):
-        """StaticAttribute : STATIC Attribute"""
-        p[2].AddChildren(self.BuildTrue('STATIC'))
-        p[0] = p[2]
-
-    # [b47]
-    def p_ExceptionMember(self, p):
-        """ExceptionMember : Const
-                           | ExceptionField
-                           | Attribute
-                           | ExceptionOperation"""
-        # Standard is (no Attribute, no ExceptionOperation):
-        # ExceptionMember : Const
-        #                 | ExceptionField
-        # FIXME: In DOMException.idl, Attributes should be changed to
-        # ExceptionFields, and Attribute removed from this rule.
-        p[0] = p[1]
-
-    # [b47.1]
-    def p_ExceptionOperation(self, p):
-        """ExceptionOperation : Type identifier '(' ')' ';'"""
-        # Needed to handle one case in DOMException.idl:
-        # // Override in a Mozilla compatible format
-        # [NotEnumerable] DOMString toString();
-        # Limited form of Operation to prevent others from being added.
-        # FIXME: Should be a stringifier instead.
-        p[0] = self.BuildNamed('ExceptionOperation', p, 2, p[1])
-
-    # Extended attributes
-    # [b49] Override base parser: remove comment field, since comments stripped
-    # FIXME: Upstream
-    def p_ExtendedAttributeList(self, p):
-        """ExtendedAttributeList : '[' ExtendedAttribute ExtendedAttributes ']'
-                                 | '[' ']'
-                                 | """
-        if len(p) > 3:
-            items = ListFromConcat(p[2], p[3])
-            p[0] = self.BuildProduction('ExtAttributes', p, 1, items)
-
-    # [b50] Allow optional trailing comma
-    # Blink-only, marked as WONTFIX in Web IDL spec:
-    # https://www.w3.org/Bugs/Public/show_bug.cgi?id=22156
-    def p_ExtendedAttributes(self, p):
-        """ExtendedAttributes : ',' ExtendedAttribute ExtendedAttributes
-                              | ','
-                              |"""
-        if len(p) > 3:
-            p[0] = ListFromConcat(p[2], p[3])
-
-    # [b51] Add ExtendedAttributeIdentAndOrIdent
-    def p_ExtendedAttribute(self, p):
-        """ExtendedAttribute : ExtendedAttributeNoArgs
-                             | ExtendedAttributeArgList
-                             | ExtendedAttributeIdent
-                             | ExtendedAttributeIdentList
-                             | ExtendedAttributeStringLiteralList
-                             | ExtendedAttributeNamedArgList"""
-        p[0] = p[1]
-
-    # [59]
-    # FIXME: Upstream UnionType
-    def p_UnionType(self, p):
-        """UnionType : '(' UnionMemberType OR UnionMemberType UnionMemberTypes ')'"""
-        members = ListFromConcat(p[2], p[4], p[5])
-        p[0] = self.BuildProduction('UnionType', p, 1, members)
-
-    # [60]
-    def p_UnionMemberType(self, p):
-        """UnionMemberType : NonAnyType
-                           | UnionType TypeSuffix
-                           | ANY '[' ']' TypeSuffix"""
-        if len(p) == 2:
-            p[0] = self.BuildProduction('Type', p, 1, p[1])
-        elif len(p) == 3:
-            p[0] = self.BuildProduction('Type', p, 1, ListFromConcat(p[1], p[2]))
-        else:
-            any_node = ListFromConcat(self.BuildProduction('Any', p, 1), p[4])
-            p[0] = self.BuildProduction('Type', p, 1, any_node)
-
-    # [61]
-    def p_UnionMemberTypes(self, p):
-        """UnionMemberTypes : OR UnionMemberType UnionMemberTypes
-                            |"""
-        if len(p) > 2:
-            p[0] = ListFromConcat(p[2], p[3])
-
-    # [70] Override base parser to remove non-standard sized array
-    # FIXME: Upstream
-    def p_TypeSuffix(self, p):
-        """TypeSuffix : '[' ']' TypeSuffix
-                      | '?' TypeSuffixStartingWithArray
-                      |"""
-        if len(p) == 4:
-            p[0] = self.BuildProduction('Array', p, 1, p[3])
-        elif len(p) == 3:
-            p[0] = ListFromConcat(self.BuildTrue('NULLABLE'), p[2])
-
-    # [b76.1] Add support for compound Extended Attribute values (A&B and A|B)
-    def p_ExtendedAttributeIdentList(self, p):
-        """ExtendedAttributeIdentList : identifier '=' identifier '&' IdentAndList
-                                      | identifier '=' identifier '|' IdentOrList"""
-        value = self.BuildAttribute('VALUE', p[3] + p[4] + p[5])
-        p[0] = self.BuildNamed('ExtAttribute', p, 1, value)
-
-    # [b76.2] A&B&C
-    def p_IdentAndList(self, p):
-        """IdentAndList : identifier '&' IdentAndList
-                        | identifier"""
-        if len(p) > 3:
-            p[0] = p[1] + p[2] + p[3]
-        else:
-            p[0] = p[1]
-
-    # [b76.3] A|B|C
-    def p_IdentOrList(self, p):
-        """IdentOrList : identifier '|' IdentOrList
-                       | identifier"""
-        if len(p) > 3:
-            p[0] = p[1] + p[2] + p[3]
-        else:
-            p[0] = p[1]
-
-    # Blink extension: Add support for compound Extended Attribute values over string literals ("A"|"B")
-    def p_ExtendedAttributeStringLiteralList(self, p):
-        """ExtendedAttributeStringLiteralList : identifier '=' StringLiteralOrList"""
-        value = self.BuildAttribute('VALUE', p[3])
-        p[0] = self.BuildNamed('ExtAttribute', p, 1, value)
-
-    # Blink extension: one or more string literals. The values aren't propagated as literals,
-    # but their by their value only.
-    def p_StringLiteralOrList(self, p):
-        """StringLiteralOrList : StringLiteral '|' StringLiteralOrList
-                               | StringLiteral"""
-        def unwrap_string(ls):
-            """Reach in and grab the string literal's "NAME"."""
-            return ls[1].value
-
-        if len(p) > 3:
-            p[0] = unwrap_string(p[1]) + p[2] + p[3]
-        else:
-            p[0] = unwrap_string(p[1])
-
-    def __dir__(self):
-        # Remove REMOVED_RULES from listing so yacc doesn't parse them
-        # FIXME: Upstream
-        keys = set(self.__dict__.keys() + dir(self.__class__))
-        for rule in REMOVED_RULES:
-            production_name = 'p_' + rule
-            if production_name in keys:
-                keys.remove(production_name)
-        return list(keys)
-
-    def __init__(self, lexer=None, verbose=False, debug=False, mute_error=False, outputdir=''):
-        lexer = lexer or BlinkIDLLexer()
-        self.lexer = lexer
-        self.tokens = lexer.KnownTokens()
-        # Using SLR (instead of LALR) generates the table faster,
-        # but produces the same output. This is ok b/c Web IDL (and Blink IDL)
-        # is an SLR grammar (as is often the case for simple LL(1) grammars).
-        self.yaccobj = yacc.yacc(module=self, start=STARTING_SYMBOL, method='SLR', debug=debug, outputdir=outputdir)
-        self.parse_debug = debug
-        self.verbose = verbose
-        self.mute_error = mute_error
-        self._parse_errors = 0
-        self._parse_warnings = 0
-        self._last_error_msg = None
-        self._last_error_lineno = 0
-        self._last_error_pos = 0
-
-
-# If run by itself, attempt to build the parser
-if __name__ == '__main__':
-    parser = BlinkIDLParser()