Lichen

Annotated translator.py

126:56ea5ebbec94
2016-10-24 Paul Boddie Re-introduced support for the generation of program structures.
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#!/usr/bin/env python
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"""
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Translate programs.
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Copyright (C) 2015, 2016 Paul Boddie <paul@boddie.org.uk>
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; either version 3 of the License, or (at your option) any later
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version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
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details.
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You should have received a copy of the GNU General Public License along with
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this program.  If not, see <http://www.gnu.org/licenses/>.
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"""
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from common import *
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from encoders import *
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from os.path import exists, join
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from os import makedirs
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import compiler
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import results
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class Translator(CommonOutput):
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    "A program translator."
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    def __init__(self, importer, deducer, optimiser, output):
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        self.importer = importer
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        self.deducer = deducer
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        self.optimiser = optimiser
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        self.output = output
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    def to_output(self):
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        output = join(self.output, "src")
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        if not exists(output):
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            makedirs(output)
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        self.check_output()
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        for module in self.importer.modules.values():
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            tm = TranslatedModule(module.name, self.importer, self.deducer, self.optimiser)
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            tm.translate(module.filename, join(output, "%s.c" % module.name))
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# Classes representing intermediate translation results.
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class TranslationResult:
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    "An abstract translation result mix-in."
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    pass
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class Expression(results.Result, TranslationResult):
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    "A general expression."
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    def __init__(self, s):
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        self.s = s
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    def __str__(self):
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        return self.s
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    def __repr__(self):
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        return "Expression(%r)" % self.s
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class TrResolvedNameRef(results.ResolvedNameRef, TranslationResult):
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    "A reference to a name in the translation."
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    def __str__(self):
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        "Return an output representation of the referenced name."
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        # Use any alias in preference to the origin of the name.
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        name = self.get_name()
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        # Use any static origin in preference to any alias.
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        # For sources, any identified static origin will be constant and thus
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        # usable directly. For targets, no constant should be assigned and thus
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        # the alias (or any plain name) will be used.
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        origin = self.static() and self.get_origin()
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        name = origin and encode_path(origin) or name and encode_path(name) or encode_path(self.name)
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        # Assignments.
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        if self.expr:
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            # Eliminate assignments between constants.
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            if self.static() and isinstance(self.expr, results.ResolvedNameRef) and self.expr.static():
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                return ""
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            else:
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                return "%s = %s" % (name, self.expr)
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        # Expressions.
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        else:
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            return name
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class TrConstantValueRef(results.ConstantValueRef, TranslationResult):
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    "A constant value reference in the translation."
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    def __str__(self):
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        return "const%d" % self.number
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class TrLiteralSequenceRef(results.LiteralSequenceRef, TranslationResult):
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    "A reference representing a sequence of values."
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    def __str__(self):
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        return str(self.node)
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class AttrResult(Expression, TranslationResult):
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    "A translation result for an attribute access."
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    def __init__(self, s, refs):
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        Expression.__init__(self, s)
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        self.refs = refs
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    def get_origin(self):
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        return self.refs and len(self.refs) == 1 and first(self.refs).get_origin()
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    def has_kind(self, kinds):
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        if not self.refs:
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            return False
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        for ref in self.refs:
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            if ref.has_kind(kinds):
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                return True
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        return False
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    def __repr__(self):
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        return "AttrResult(%r, %r)" % (self.s, self.origin)
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class PredefinedConstantRef(AttrResult):
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    "A predefined constant reference."
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    def __init__(self, value):
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        self.value = value
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    def __str__(self):
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        return self.value
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    def __repr__(self):
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        return "PredefinedConstantRef(%r)" % self.value
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def make_expression(expr):
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    "Make a new expression from the existing 'expr'."
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    if isinstance(expr, results.Result):
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        return expr
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    else:
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        return Expression(str(expr))
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# The actual translation process itself.
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class TranslatedModule(CommonModule):
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    "A module translator."
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    def __init__(self, name, importer, deducer, optimiser):
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        CommonModule.__init__(self, name, importer)
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        self.deducer = deducer
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        self.optimiser = optimiser
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        # Output stream.
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        self.out = None
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        self.indent = 0
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        self.tabstop = "    "
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        # Recorded namespaces.
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        self.namespaces = []
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        self.in_conditional = False
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        # Attribute access counting.
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        self.attr_accesses = {}
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    def __repr__(self):
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        return "TranslatedModule(%r, %r)" % (self.name, self.importer)
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    def translate(self, filename, output_filename):
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        """
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        Parse the file having the given 'filename', writing the translation to
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        the given 'output_filename'.
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        """
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        self.parse_file(filename)
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        # Collect function namespaces for separate processing.
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        self.record_namespaces(self.astnode)
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        # Reset the lambda naming (in order to obtain the same names again) and
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        # translate the program.
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        self.reset_lambdas()
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        self.out = open(output_filename, "w")
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        try:
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            # Process namespaces, writing the translation.
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            for path, node in self.namespaces:
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                self.process_namespace(path, node)
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            # Process the module namespace including class namespaces.
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            self.process_namespace([], self.astnode)
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        finally:
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            self.out.close()
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    def have_object(self):
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        "Return whether a namespace is a recorded object."
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        return self.importer.objects.get(self.get_namespace_path())
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    def get_builtin(self, name):
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        return self.importer.get_object("__builtins__.%s" % name)
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    def in_method(self, path):
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        class_name, method_name = path.rsplit(".", 1)
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        return self.importer.classes.has_key(class_name) and class_name
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    # Namespace recording.
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    def record_namespaces(self, node):
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        "Process the program structure 'node', recording namespaces."
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        for n in node.getChildNodes():
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            self.record_namespaces_in_node(n)
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    def record_namespaces_in_node(self, node):
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        "Process the program structure 'node', recording namespaces."
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        # Function namespaces within modules, classes and other functions.
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        # Functions appearing within conditional statements are given arbitrary
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        # names.
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        if isinstance(node, compiler.ast.Function):
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            self.record_function_node(node, (self.in_conditional or self.in_function) and self.get_lambda_name() or node.name)
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        elif isinstance(node, compiler.ast.Lambda):
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            self.record_function_node(node, self.get_lambda_name())
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        # Classes are visited, but may be ignored if inside functions.
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        elif isinstance(node, compiler.ast.Class):
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            self.enter_namespace(node.name)
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            if self.have_object():
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                self.record_namespaces(node)
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            self.exit_namespace()
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        # Conditional nodes are tracked so that function definitions may be
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        # handled. Since "for" loops are converted to "while" loops, they are
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        # included here.
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        elif isinstance(node, (compiler.ast.For, compiler.ast.If, compiler.ast.While)):
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            in_conditional = self.in_conditional
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            self.in_conditional = True
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            self.record_namespaces(node)
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            self.in_conditional = in_conditional
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        # All other nodes are processed depth-first.
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        else:
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            self.record_namespaces(node)
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    def record_function_node(self, n, name):
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        """
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        Record the given function, lambda, if expression or list comprehension
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        node 'n' with the given 'name'.
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        """
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        self.in_function = True
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        self.enter_namespace(name)
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        if self.have_object():
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            # Record the namespace path and the node itself.
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            self.namespaces.append((self.namespace_path[:], n))
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            self.record_namespaces_in_node(n.code)
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        self.exit_namespace()
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        self.in_function = False
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    # Constant referencing.
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    def get_literal_instance(self, n, name):
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        """
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        For node 'n', return a reference for the type of the given 'name'.
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        """
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        ref = self.get_builtin(name)
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        if name in ("dict", "list", "tuple"):
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            return self.process_literal_sequence_node(n, name, ref, TrLiteralSequenceRef)
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        else:
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            path = self.get_namespace_path()
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            local_number = self.importer.all_constants[path][n.value]
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            constant_name = "$c%d" % local_number
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            objpath = self.get_object_path(constant_name)
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            number = self.optimiser.constant_numbers[objpath]
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            return TrConstantValueRef(constant_name, ref.instance_of(), n.value, number)
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    # Namespace translation.
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    def process_namespace(self, path, node):
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        """
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        Process the namespace for the given 'path' defined by the given 'node'.
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        """
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        self.namespace_path = path
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        if isinstance(node, (compiler.ast.Function, compiler.ast.Lambda)):
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            self.in_function = True
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            self.process_function_body_node(node)
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        else:
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            self.in_function = False
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            self.start_module()
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            self.process_structure(node)
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            self.end_module()
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    def process_structure(self, node):
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        "Process the given 'node' or result."
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        if isinstance(node, results.Result):
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            return node
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        else:
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            return CommonModule.process_structure(self, node)
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    def process_structure_node(self, n):
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        "Process the individual node 'n'."
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        # Plain statements emit their expressions.
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        if isinstance(n, compiler.ast.Discard):
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            expr = self.process_structure_node(n.expr)
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            self.statement(expr)
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        # Nodes using operator module functions.
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        elif isinstance(n, compiler.ast.Operator):
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            return self.process_operator_node(n)
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        elif isinstance(n, compiler.ast.AugAssign):
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            self.process_augassign_node(n)
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        elif isinstance(n, compiler.ast.Compare):
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            return self.process_compare_node(n)
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        elif isinstance(n, compiler.ast.Slice):
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            return self.process_slice_node(n)
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        elif isinstance(n, compiler.ast.Sliceobj):
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            return self.process_sliceobj_node(n)
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        elif isinstance(n, compiler.ast.Subscript):
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            return self.process_subscript_node(n)
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        # Classes are visited, but may be ignored if inside functions.
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        elif isinstance(n, compiler.ast.Class):
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            self.process_class_node(n)
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        # Functions within namespaces have any dynamic defaults initialised.
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        elif isinstance(n, compiler.ast.Function):
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            self.process_function_node(n)
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        # Lambdas are replaced with references to separately-generated
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        # functions.
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        elif isinstance(n, compiler.ast.Lambda):
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            return self.process_lambda_node(n)
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        # Assignments.
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        elif isinstance(n, compiler.ast.Assign):
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            # Handle each assignment node.
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            for node in n.nodes:
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                self.process_assignment_node(node, n.expr)
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        # Assignments within non-Assign nodes.
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        # NOTE: Cover all possible nodes employing these.
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        elif isinstance(n, compiler.ast.AssName):
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            self.process_assignment_node(n, compiler.ast.Name("$temp"))
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        elif isinstance(n, compiler.ast.AssAttr):
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            self.process_attribute_access(n)
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        # Accesses.
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        elif isinstance(n, compiler.ast.Getattr):
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            return self.process_attribute_access(n)
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        # Names.
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        elif isinstance(n, compiler.ast.Name):
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            return self.process_name_node(n)
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        # Loops and conditionals.
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        elif isinstance(n, compiler.ast.For):
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            self.process_for_node(n)
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        elif isinstance(n, compiler.ast.While):
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            self.process_while_node(n)
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        elif isinstance(n, compiler.ast.If):
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            self.process_if_node(n)
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        elif isinstance(n, (compiler.ast.And, compiler.ast.Or)):
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            return self.process_logical_node(n)
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        elif isinstance(n, compiler.ast.Not):
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            return self.process_not_node(n)
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        # Exception control-flow tracking.
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        elif isinstance(n, compiler.ast.TryExcept):
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            self.process_try_node(n)
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        elif isinstance(n, compiler.ast.TryFinally):
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            self.process_try_finally_node(n)
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        # Control-flow modification statements.
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        elif isinstance(n, compiler.ast.Break):
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            self.writeline("break;")
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        elif isinstance(n, compiler.ast.Continue):
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            self.writeline("continue;")
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        elif isinstance(n, compiler.ast.Return):
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            expr = self.process_structure_node(n.value)
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            if expr:
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                self.writeline("return %s;" % expr)
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            else:
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                self.writeline("return;")
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        # Invocations.
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        elif isinstance(n, compiler.ast.CallFunc):
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            return self.process_invocation_node(n)
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        elif isinstance(n, compiler.ast.Keyword):
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            return self.process_structure_node(n.expr)
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        # Constant usage.
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        elif isinstance(n, compiler.ast.Const):
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            return self.get_literal_instance(n, n.value.__class__.__name__)
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        elif isinstance(n, compiler.ast.Dict):
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            return self.get_literal_instance(n, "dict")
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        elif isinstance(n, compiler.ast.List):
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            return self.get_literal_instance(n, "list")
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        elif isinstance(n, compiler.ast.Tuple):
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            return self.get_literal_instance(n, "tuple")
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        # All other nodes are processed depth-first.
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        else:
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            self.process_structure(n)
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    def process_assignment_node(self, n, expr):
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        "Process the individual node 'n' to be assigned the contents of 'expr'."
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        # Names and attributes are assigned the entire expression.
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        if isinstance(n, compiler.ast.AssName):
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            name_ref = self.process_name_node(n, self.process_structure_node(expr))
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            self.statement(name_ref)
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        elif isinstance(n, compiler.ast.AssAttr):
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            in_assignment = self.in_assignment
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            self.in_assignment = self.process_structure_node(expr)
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            self.statement(self.process_attribute_access(n))
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            self.in_assignment = in_assignment
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        # Lists and tuples are matched against the expression and their
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        # items assigned to expression items.
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        elif isinstance(n, (compiler.ast.AssList, compiler.ast.AssTuple)):
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            self.process_assignment_node_items(n, expr)
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        # Slices and subscripts are permitted within assignment nodes.
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        elif isinstance(n, compiler.ast.Slice):
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            self.statement(self.process_slice_node(n, expr))
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        elif isinstance(n, compiler.ast.Subscript):
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            self.statement(self.process_subscript_node(n, expr))
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    def process_attribute_access(self, n):
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        """
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        Process the given attribute access node 'n'.
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        Where a name is provided, a single access should be recorded
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        involving potentially many attributes, thus providing a path to an
paul@113 530
        object. The remaining attributes are then accessed dynamically.
paul@113 531
        The remaining accesses could be deduced and computed, but they would
paul@113 532
        also need to be tested.
paul@113 533
paul@113 534
        Where no name is provided, potentially many accesses should be
paul@113 535
        recorded, one per attribute name. These could be used to provide
paul@113 536
        computed accesses, but the accessors would need to be tested in each
paul@113 537
        case.
paul@113 538
        """
paul@113 539
paul@113 540
        # Obtain any completed chain and return the reference to it.
paul@113 541
paul@113 542
        attr_expr = self.process_attribute_chain(n)
paul@113 543
        if self.have_access_expression(n):
paul@113 544
            return attr_expr
paul@113 545
paul@113 546
        # Where the start of the chain of attributes has been reached, process
paul@113 547
        # the complete access.
paul@113 548
paul@113 549
        name_ref = attr_expr and attr_expr.is_name() and attr_expr
paul@113 550
        name = name_ref and name_ref.name or None
paul@113 551
paul@113 552
        location = self.get_access_location(name)
paul@113 553
        refs = self.get_referenced_attributes(location)
paul@113 554
paul@113 555
        # Generate access instructions.
paul@113 556
paul@113 557
        subs = {
paul@113 558
            "<expr>" : str(attr_expr),
paul@124 559
            "<assexpr>" : str(self.in_assignment),
paul@113 560
            "<context>" : "__tmp_context",
paul@113 561
            "<accessor>" : "__tmp_value",
paul@113 562
            }
paul@113 563
paul@113 564
        output = []
paul@113 565
paul@113 566
        for instruction in self.optimiser.access_instructions[location]:
paul@113 567
            output.append(encode_access_instruction(instruction, subs))
paul@113 568
paul@113 569
        out = "(\n%s\n)" % ",\n".join(output)
paul@113 570
paul@113 571
        del self.attrs[0]
paul@113 572
        return AttrResult(out, refs)
paul@113 573
paul@113 574
    def get_referenced_attributes(self, location):
paul@113 575
paul@113 576
        """
paul@113 577
        Convert 'location' to the form used by the deducer and retrieve any
paul@113 578
        identified attribute.
paul@113 579
        """
paul@113 580
paul@113 581
        access_location = self.deducer.const_accesses.get(location)
paul@113 582
        refs = []
paul@113 583
        for attrtype, objpath, attr in self.deducer.referenced_attrs[access_location or location]:
paul@113 584
            refs.append(attr)
paul@113 585
        return refs
paul@113 586
paul@113 587
    def get_access_location(self, name):
paul@113 588
paul@113 589
        """
paul@113 590
        Using the current namespace and the given 'name', return the access
paul@113 591
        location.
paul@113 592
        """
paul@113 593
paul@113 594
        path = self.get_path_for_access()
paul@113 595
paul@113 596
        # Get the location used by the deducer and optimiser and find any
paul@113 597
        # recorded access.
paul@113 598
paul@113 599
        attrnames = ".".join(self.attrs)
paul@113 600
        access_number = self.get_access_number(path, name, attrnames)
paul@113 601
        self.update_access_number(path, name, attrnames)
paul@113 602
        return (path, name, attrnames, access_number)
paul@113 603
paul@113 604
    def get_access_number(self, path, name, attrnames):
paul@113 605
        access = name, attrnames
paul@113 606
        if self.attr_accesses.has_key(path) and self.attr_accesses[path].has_key(access):
paul@113 607
            return self.attr_accesses[path][access]
paul@113 608
        else:
paul@113 609
            return 0
paul@113 610
paul@113 611
    def update_access_number(self, path, name, attrnames):
paul@113 612
        access = name, attrnames
paul@113 613
        if name:
paul@113 614
            init_item(self.attr_accesses, path, dict)
paul@113 615
            init_item(self.attr_accesses[path], access, lambda: 1)
paul@113 616
paul@113 617
    def process_class_node(self, n):
paul@113 618
paul@113 619
        "Process the given class node 'n'."
paul@113 620
paul@113 621
        self.enter_namespace(n.name)
paul@113 622
paul@113 623
        if self.have_object():
paul@113 624
            class_name = self.get_namespace_path()
paul@113 625
            self.write_comment("Class: %s" % class_name)
paul@113 626
paul@113 627
            self.process_structure(n)
paul@113 628
paul@113 629
        self.exit_namespace()
paul@113 630
paul@113 631
    def process_function_body_node(self, n):
paul@113 632
paul@113 633
        """
paul@113 634
        Process the given function, lambda, if expression or list comprehension
paul@113 635
        node 'n', generating the body.
paul@113 636
        """
paul@113 637
paul@113 638
        function_name = self.get_namespace_path()
paul@113 639
        self.start_function(function_name)
paul@113 640
paul@113 641
        # Process the function body.
paul@113 642
paul@113 643
        in_conditional = self.in_conditional
paul@113 644
        self.in_conditional = False
paul@113 645
paul@113 646
        expr = self.process_structure_node(n.code)
paul@113 647
        if expr:
paul@113 648
            self.writeline("return %s;" % expr)
paul@113 649
paul@113 650
        self.in_conditional = in_conditional
paul@113 651
paul@113 652
        self.end_function()
paul@113 653
paul@113 654
    def process_function_node(self, n):
paul@113 655
paul@113 656
        """
paul@113 657
        Process the given function, lambda, if expression or list comprehension
paul@113 658
        node 'n', generating any initialisation statements.
paul@113 659
        """
paul@113 660
paul@113 661
        # Where a function is declared conditionally, use a separate name for
paul@113 662
        # the definition, and assign the definition to the stated name.
paul@113 663
paul@113 664
        if self.in_conditional or self.in_function:
paul@113 665
            original_name = n.name
paul@113 666
            name = self.get_lambda_name()
paul@113 667
        else:
paul@113 668
            original_name = None
paul@113 669
            name = n.name
paul@113 670
paul@113 671
        # Obtain details of the defaults.
paul@113 672
paul@113 673
        defaults = self.process_function_defaults(n, name, self.get_object_path(name))
paul@113 674
        if defaults:
paul@113 675
            for default in defaults:
paul@113 676
                self.writeline("%s;" % default)
paul@113 677
paul@113 678
        # Where a function is set conditionally, assign the name.
paul@113 679
paul@113 680
        if original_name:
paul@113 681
            self.process_assignment_for_function(original_name, name)
paul@113 682
paul@113 683
    def process_function_defaults(self, n, name, instance_name):
paul@113 684
paul@113 685
        """
paul@113 686
        Process the given function or lambda node 'n', initialising defaults
paul@113 687
        that are dynamically set. The given 'name' indicates the name of the
paul@113 688
        function. The given 'instance_name' indicates the name of any separate
paul@113 689
        instance of the function created to hold the defaults.
paul@113 690
paul@113 691
        Return a list of operations setting defaults on a function instance.
paul@113 692
        """
paul@113 693
paul@113 694
        function_name = self.get_object_path(name)
paul@113 695
        function_defaults = self.importer.function_defaults.get(function_name)
paul@113 696
        if not function_defaults:
paul@113 697
            return None
paul@113 698
paul@113 699
        # Determine whether any unidentified defaults are involved.
paul@113 700
paul@113 701
        need_defaults = [argname for argname, default in function_defaults if default.has_kind("<var>")]
paul@113 702
        if not need_defaults:
paul@113 703
            return None
paul@113 704
paul@113 705
        # Where defaults are involved but cannot be identified, obtain a new
paul@113 706
        # instance of the lambda and populate the defaults.
paul@113 707
paul@113 708
        defaults = []
paul@113 709
paul@113 710
        # Join the original defaults with the inspected defaults.
paul@113 711
paul@113 712
        original_defaults = [(argname, default) for (argname, default) in compiler.ast.get_defaults(n) if default]
paul@113 713
paul@113 714
        for i, (original, inspected) in enumerate(map(None, original_defaults, function_defaults)):
paul@113 715
paul@113 716
            # Obtain any reference for the default.
paul@113 717
paul@113 718
            if original:
paul@113 719
                argname, default = original
paul@113 720
                name_ref = self.process_structure_node(default)
paul@113 721
            elif inspected:
paul@113 722
                argname, default = inspected
paul@113 723
                name_ref = TrResolvedNameRef(argname, default)
paul@113 724
            else:
paul@113 725
                continue
paul@113 726
paul@113 727
            if name_ref:
paul@113 728
                defaults.append("__SETDEFAULT(%s, %s, %s)" % (encode_path(instance_name), i, name_ref))
paul@113 729
paul@113 730
        return defaults
paul@113 731
paul@113 732
    def process_if_node(self, n):
paul@113 733
paul@113 734
        """
paul@113 735
        Process the given "if" node 'n'.
paul@113 736
        """
paul@113 737
paul@113 738
        first = True
paul@113 739
        for test, body in n.tests:
paul@113 740
            test_ref = self.process_structure_node(test)
paul@113 741
            self.start_if(first, test_ref)
paul@113 742
paul@113 743
            in_conditional = self.in_conditional
paul@113 744
            self.in_conditional = True
paul@113 745
            self.process_structure_node(body)
paul@113 746
            self.in_conditional = in_conditional
paul@113 747
paul@113 748
            self.end_if()
paul@113 749
            first = False
paul@113 750
paul@113 751
        if n.else_:
paul@113 752
            self.start_else()
paul@113 753
            self.process_structure_node(n.else_)
paul@113 754
            self.end_else()
paul@113 755
paul@113 756
    def process_invocation_node(self, n):
paul@113 757
paul@113 758
        "Process the given invocation node 'n'."
paul@113 759
paul@113 760
        expr = self.process_structure_node(n.node)
paul@113 761
        objpath = expr.get_origin()
paul@118 762
        target = None
paul@113 763
paul@113 764
        # Obtain details of the callable.
paul@113 765
paul@113 766
        if objpath:
paul@113 767
            parameters = self.importer.function_parameters.get(objpath)
paul@118 768
            if expr.has_kind("<class>"):
paul@118 769
                target = encode_instantiator_pointer(objpath)
paul@118 770
            elif expr.has_kind("<function>"):
paul@118 771
                target = encode_function_pointer(objpath)
paul@113 772
        else:
paul@113 773
            parameters = None
paul@113 774
paul@113 775
        stages = []
paul@113 776
paul@122 777
        # First, the invocation target is presented.
paul@113 778
paul@113 779
        stages.append("__tmp_target = %s" % expr)
paul@122 780
paul@122 781
        # Arguments are presented in a temporary frame array with any context
paul@122 782
        # always being the first argument (although it may be set to null for
paul@122 783
        # invocations where it would be unused).
paul@122 784
paul@122 785
        args = ["__CONTEXT_AS_VALUE(__tmp_target)"]
paul@122 786
        args += [None] * (not parameters and len(n.args) or parameters and len(parameters) or 0)
paul@122 787
        kwcodes = []
paul@122 788
        kwargs = []
paul@122 789
paul@122 790
        for i, arg in enumerate(n.args):
paul@122 791
            argexpr = self.process_structure_node(arg)
paul@122 792
paul@122 793
            # Store a keyword argument, either in the argument list or
paul@122 794
            # in a separate keyword argument list for subsequent lookup.
paul@122 795
paul@122 796
            if isinstance(arg, compiler.ast.Keyword):
paul@113 797
paul@122 798
                # With knowledge of the target, store the keyword
paul@122 799
                # argument directly.
paul@122 800
paul@122 801
                if parameters:
paul@122 802
                    argnum = parameters.index(arg.name)
paul@122 803
                    args[argnum+1] = str(argexpr)
paul@122 804
paul@122 805
                # Otherwise, store the details in a separate collection.
paul@122 806
paul@122 807
                else:
paul@122 808
                    kwargs.append(str(argexpr))
paul@122 809
                    kwcodes.append("{%s, %s}" % (
paul@122 810
                        encode_symbol("ppos", arg.name),
paul@122 811
                        encode_symbol("pcode", arg.name)))
paul@122 812
paul@122 813
            else:
paul@122 814
                args[i+1] = str(argexpr)
paul@113 815
paul@113 816
        # Defaults are added to the frame where arguments are missing.
paul@113 817
paul@122 818
        if parameters:
paul@122 819
            function_defaults = self.importer.function_defaults.get(objpath)
paul@122 820
            if function_defaults:
paul@122 821
paul@122 822
                # Visit each default and set any missing arguments.
paul@122 823
paul@122 824
                for i, (argname, default) in enumerate(function_defaults):
paul@122 825
                    argnum = parameters.index(argname)
paul@122 826
                    if not args[argnum+1]:
paul@122 827
                        args[argnum+1] = "__GETDEFAULT(%s, %d)" % (target, i)
paul@122 828
paul@122 829
        if None in args:
paul@122 830
            print self.get_namespace_path()
paul@122 831
            print n
paul@122 832
            print expr
paul@122 833
            print target
paul@122 834
            print args
paul@122 835
paul@122 836
        argstr = "__ARGS(%s)" % ", ".join(args)
paul@122 837
        kwargstr = kwargs and ("__ARGS(%s)" % ", ".join(kwargs)) or "0"
paul@122 838
        kwcodestr = kwcodes and ("__KWARGS(%s)" % ", ".join(kwcodes)) or "0"
paul@122 839
paul@122 840
        # The callable is then obtained.
paul@113 841
paul@118 842
        if target:
paul@122 843
            callable = "__tmp_target"
paul@118 844
paul@118 845
        elif self.always_callable:
paul@122 846
            callable = "__load_via_object(__tmp_target, %s)" % \
paul@113 847
                     encode_symbol("pos", "__fn__")
paul@113 848
        else:
paul@122 849
            callable = "__check_and_load_via_object(__tmp_target, %s, %s)" % (
paul@113 850
                     encode_symbol("pos", "__fn__"), encode_symbol("code", "__fn__"))
paul@113 851
paul@122 852
        stages.append(callable)
paul@122 853
paul@122 854
        # With a known target, the function is obtained directly and called.
paul@122 855
paul@122 856
        if target:
paul@122 857
            output = "(\n%s.fn\n)(%s)" % (",\n".join(stages), argstr)
paul@113 858
paul@122 859
        # With unknown targets, the generic invocation function is applied to
paul@122 860
        # the callable and argument collections.
paul@113 861
paul@122 862
        else:
paul@122 863
            output = "__invoke(\n(\n%s\n),\n%d, %s, %s,\n%d, %s\n)" % (
paul@122 864
                ",\n".join(stages),
paul@122 865
                len(kwargs), kwcodestr, kwargstr,
paul@122 866
                len(args), argstr)
paul@122 867
paul@122 868
        return make_expression(output)
paul@113 869
paul@113 870
    def always_callable(self, refs):
paul@113 871
paul@113 872
        "Determine whether all 'refs' are callable."
paul@113 873
paul@113 874
        for ref in refs:
paul@113 875
            if not ref.static():
paul@113 876
                return False
paul@113 877
            else:
paul@113 878
                origin = ref.final()
paul@113 879
                if not self.importer.get_attribute(origin, "__fn__"):
paul@113 880
                    return False
paul@113 881
        return True
paul@113 882
paul@113 883
    def need_default_arguments(self, objpath, nargs):
paul@113 884
paul@113 885
        """
paul@113 886
        Return whether any default arguments are needed when invoking the object
paul@113 887
        given by 'objpath'.
paul@113 888
        """
paul@113 889
paul@113 890
        parameters = self.importer.function_parameters.get(objpath)
paul@113 891
        return nargs < len(parameters)
paul@113 892
paul@113 893
    def process_lambda_node(self, n):
paul@113 894
paul@113 895
        "Process the given lambda node 'n'."
paul@113 896
paul@113 897
        name = self.get_lambda_name()
paul@113 898
        function_name = self.get_object_path(name)
paul@113 899
paul@113 900
        defaults = self.process_function_defaults(n, name, "__tmp")
paul@113 901
        if not defaults:
paul@113 902
            return make_expression(encode_path(function_name))
paul@113 903
        else:
paul@113 904
            return make_expression("(__COPY(%s, __tmp), %s)" % (encode_path(function_name), ", ".join(defaults)))
paul@113 905
paul@113 906
    def process_logical_node(self, n):
paul@113 907
paul@113 908
        "Process the given operator node 'n'."
paul@113 909
paul@113 910
        if isinstance(n, compiler.ast.And):
paul@113 911
            op = " && "
paul@113 912
        else:
paul@113 913
            op = " || "
paul@113 914
paul@113 915
        # NOTE: This needs to evaluate whether the operands are true or false
paul@113 916
        # NOTE: according to Python rules.
paul@113 917
paul@113 918
        results = [("(%s)" % self.process_structure_node(node)) for node in n.nodes]
paul@113 919
        return make_expression("(%s)" % op.join(results))
paul@113 920
paul@113 921
    def process_name_node(self, n, expr=None):
paul@113 922
paul@113 923
        "Process the given name node 'n' with the optional assignment 'expr'."
paul@113 924
paul@113 925
        # Determine whether the name refers to a static external entity.
paul@113 926
paul@113 927
        if n.name in predefined_constants:
paul@113 928
            return PredefinedConstantRef(n.name)
paul@113 929
paul@113 930
        # Convert literal references.
paul@113 931
paul@113 932
        elif n.name.startswith("$L"):
paul@113 933
            literal_name = n.name[len("$L"):]
paul@113 934
            ref = self.importer.get_object("__builtins__.%s" % literal_name)
paul@113 935
            return TrResolvedNameRef(n.name, ref)
paul@113 936
paul@113 937
        # Convert operator function names to references.
paul@113 938
paul@113 939
        elif n.name.startswith("$op"):
paul@113 940
            opname = n.name[len("$op"):]
paul@113 941
            ref = self.importer.get_object("operator.%s" % opname)
paul@113 942
            return TrResolvedNameRef(n.name, ref)
paul@113 943
paul@113 944
        # Get the appropriate name for the name reference, using the same method
paul@113 945
        # as in the inspector.
paul@113 946
paul@113 947
        path = self.get_object_path(n.name)
paul@113 948
        ref = self.importer.get_object(path)
paul@113 949
        name = self.get_name_for_tracking(n.name, ref and ref.final())
paul@113 950
paul@113 951
        # Get the static identity of the name.
paul@113 952
paul@113 953
        ref = self.importer.identify(path)
paul@113 954
paul@113 955
        # Obtain any resolved names for non-assignment names.
paul@113 956
paul@113 957
        if not expr and not ref and self.in_function:
paul@113 958
            locals = self.importer.function_locals.get(self.get_namespace_path())
paul@113 959
            ref = locals and locals.get(n.name)
paul@113 960
paul@113 961
        # Qualified names are used for resolved static references or for
paul@113 962
        # static namespace members. The reference should be configured to return
paul@113 963
        # such names.
paul@113 964
paul@113 965
        return TrResolvedNameRef(name, ref, expr=expr)
paul@113 966
paul@113 967
    def process_not_node(self, n):
paul@113 968
paul@113 969
        "Process the given operator node 'n'."
paul@113 970
paul@113 971
        # NOTE: This needs to evaluate whether the operand is true or false
paul@113 972
        # NOTE: according to Python rules.
paul@113 973
paul@113 974
        return make_expression("(!(%s))" % n.expr)
paul@113 975
paul@113 976
    def process_try_node(self, n):
paul@113 977
paul@113 978
        """
paul@113 979
        Process the given "try...except" node 'n'.
paul@113 980
        """
paul@113 981
paul@113 982
        # NOTE: Placeholders/macros.
paul@113 983
paul@113 984
        self.writeline("TRY")
paul@113 985
        self.writeline("{")
paul@113 986
        self.indent += 1
paul@113 987
        self.process_structure_node(n.body)
paul@113 988
        self.indent -= 1
paul@113 989
        self.writeline("}")
paul@113 990
paul@113 991
        for name, var, handler in n.handlers:
paul@113 992
            if name is not None:
paul@113 993
                name_ref = self.process_structure_node(name)
paul@113 994
                self.writeline("EXCEPT(%s)" % name_ref)
paul@113 995
paul@113 996
            self.writeline("{")
paul@113 997
            self.indent += 1
paul@113 998
paul@113 999
            # Establish the local for the handler.
paul@113 1000
            # NOTE: Need to provide the exception value.
paul@113 1001
paul@113 1002
            if var is not None:
paul@113 1003
                var_ref = self.process_structure_node(var)
paul@113 1004
paul@113 1005
            if handler is not None:
paul@113 1006
                self.process_structure_node(handler)
paul@113 1007
paul@113 1008
            self.indent -= 1
paul@113 1009
            self.writeline("}")
paul@113 1010
paul@113 1011
        if n.else_:
paul@113 1012
            self.process_structure_node(n.else_)
paul@113 1013
paul@113 1014
    def process_try_finally_node(self, n):
paul@113 1015
paul@113 1016
        """
paul@113 1017
        Process the given "try...finally" node 'n'.
paul@113 1018
        """
paul@113 1019
paul@113 1020
        # NOTE: Placeholders/macros.
paul@113 1021
paul@113 1022
        self.writeline("TRY")
paul@113 1023
        self.writeline("{")
paul@113 1024
        self.indent += 1
paul@113 1025
        self.process_structure_node(n.body)
paul@113 1026
        self.indent -= 1
paul@113 1027
        self.writeline("}")
paul@113 1028
        self.writeline("FINALLY")
paul@113 1029
        self.writeline("{")
paul@113 1030
        self.indent += 1
paul@113 1031
        self.process_structure_node(n.final)
paul@113 1032
        self.indent -= 1
paul@113 1033
        self.writeline("}")
paul@113 1034
paul@113 1035
    def process_while_node(self, n):
paul@113 1036
paul@113 1037
        "Process the given while node 'n'."
paul@113 1038
paul@113 1039
        self.writeline("while (1)")
paul@113 1040
        self.writeline("{")
paul@113 1041
        self.indent += 1
paul@113 1042
        test = self.process_structure_node(n.test)
paul@113 1043
paul@113 1044
        # Emit the loop termination condition unless "while <true value>" is
paul@113 1045
        # indicated.
paul@113 1046
paul@113 1047
        if not (isinstance(test, PredefinedConstantRef) and test.value):
paul@113 1048
paul@113 1049
            # NOTE: This needs to evaluate whether the operand is true or false
paul@113 1050
            # NOTE: according to Python rules.
paul@113 1051
paul@113 1052
            self.writeline("if (!(%s))" % test)
paul@113 1053
            self.writeline("{")
paul@113 1054
            self.indent += 1
paul@113 1055
            if n.else_:
paul@113 1056
                self.process_structure_node(n.else_)
paul@113 1057
            self.writeline("break;")
paul@113 1058
            self.indent -= 1
paul@113 1059
            self.writeline("}")
paul@113 1060
paul@113 1061
        in_conditional = self.in_conditional
paul@113 1062
        self.in_conditional = True
paul@113 1063
        self.process_structure_node(n.body)
paul@113 1064
        self.in_conditional = in_conditional
paul@113 1065
paul@113 1066
        self.indent -= 1
paul@113 1067
        self.writeline("}")
paul@113 1068
paul@113 1069
    # Output generation.
paul@113 1070
paul@113 1071
    def start_module(self):
paul@113 1072
        print >>self.out, "void __main_%s()" % encode_path(self.name)
paul@113 1073
        print >>self.out, "{"
paul@113 1074
        self.indent += 1
paul@113 1075
paul@113 1076
    def end_module(self):
paul@113 1077
        self.indent -= 1
paul@113 1078
        self.end_function()
paul@113 1079
paul@113 1080
    def start_function(self, name):
paul@113 1081
        print >>self.out, "__attr %s(__attr __args[])" % encode_function_pointer(name)
paul@113 1082
        print >>self.out, "{"
paul@113 1083
        self.indent += 1
paul@113 1084
paul@113 1085
        # Obtain local names from parameters.
paul@113 1086
paul@113 1087
        parameters = self.importer.function_parameters[name]
paul@113 1088
        names = []
paul@113 1089
        locals = self.importer.function_locals[name].keys()
paul@113 1090
paul@113 1091
        for n in locals:
paul@113 1092
paul@113 1093
            # Filter out special names and parameters. Note that self is a local
paul@113 1094
            # regardless of whether it originally appeared in the parameters or
paul@113 1095
            # not.
paul@113 1096
paul@113 1097
            if n.startswith("$l") or n in parameters or n == "self":
paul@113 1098
                continue
paul@113 1099
            names.append(encode_path(n))
paul@113 1100
paul@113 1101
        # Emit required local names.
paul@113 1102
paul@113 1103
        if names:
paul@113 1104
            names.sort()
paul@113 1105
            self.writeline("__attr %s;" % ", ".join(names))
paul@113 1106
paul@113 1107
        # Generate any self reference.
paul@113 1108
paul@113 1109
        if self.in_method(name):
paul@113 1110
            self.writeline("#define self (__args[0])")
paul@113 1111
paul@113 1112
        # Generate aliases for the parameters.
paul@113 1113
paul@113 1114
        for i, parameter in enumerate(parameters):
paul@113 1115
            self.writeline("#define %s (__args[%d])" % (encode_path(parameter), i+1))
paul@113 1116
paul@113 1117
    def end_function(self):
paul@113 1118
        self.indent -= 1
paul@113 1119
        print >>self.out, "}"
paul@113 1120
paul@113 1121
    def start_if(self, first, test_ref):
paul@113 1122
paul@113 1123
        # NOTE: This needs to evaluate whether the operand is true or false
paul@113 1124
        # NOTE: according to Python rules.
paul@113 1125
paul@113 1126
        self.writeline("%sif (%s)" % (not first and "else " or "", test_ref))
paul@113 1127
        self.writeline("{")
paul@113 1128
        self.indent += 1
paul@113 1129
paul@113 1130
    def end_if(self):
paul@113 1131
        self.indent -= 1
paul@113 1132
        self.writeline("}")
paul@113 1133
paul@113 1134
    def start_else(self):
paul@113 1135
        self.writeline("else")
paul@113 1136
        self.writeline("{")
paul@113 1137
        self.indent += 1
paul@113 1138
paul@113 1139
    def end_else(self):
paul@113 1140
        self.indent -= 1
paul@113 1141
        self.writeline("}")
paul@113 1142
paul@113 1143
    def statement(self, expr):
paul@113 1144
        # NOTE: Should never be None.
paul@113 1145
        if not expr:
paul@113 1146
            self.writeline("...;")
paul@113 1147
        s = str(expr)
paul@113 1148
        if s:
paul@113 1149
            self.writeline("%s;" % s)
paul@113 1150
paul@113 1151
    def statements(self, results):
paul@113 1152
        for result in results:
paul@113 1153
            self.statement(result)
paul@113 1154
paul@113 1155
    def pad(self, extra=0):
paul@113 1156
        return (self.indent + extra) * self.tabstop
paul@113 1157
paul@113 1158
    def indenttext(self, s, levels):
paul@116 1159
        lines = s.split("\n")
paul@116 1160
        out = [lines[0]]
paul@116 1161
        for line in lines[1:]:
paul@116 1162
            out.append(levels * self.tabstop + line)
paul@116 1163
            if line.endswith("("):
paul@116 1164
                levels += 1
paul@122 1165
            elif line.startswith(")"):
paul@116 1166
                levels -= 1
paul@116 1167
        return "\n".join(out)
paul@113 1168
paul@113 1169
    def writeline(self, s):
paul@113 1170
        print >>self.out, "%s%s" % (self.pad(), self.indenttext(s, self.indent + 1))
paul@113 1171
paul@113 1172
    def write_comment(self, s):
paul@113 1173
        self.writeline("/* %s */" % s)
paul@113 1174
paul@113 1175
# vim: tabstop=4 expandtab shiftwidth=4