Cython/Compiler/ParseTreeTransforms.py

   1
   2 import cython
   3 cython.declare(PyrexTypes=object, Naming=object, ExprNodes=object, Nodes=object,
   4                Options=object, UtilNodes=object, ModuleNode=object,
   5                LetNode=object, LetRefNode=object, TreeFragment=object,
   6                TemplateTransform=object, EncodedString=object,
   7                error=object, warning=object, copy=object)
   8
   9 import PyrexTypes
  10 import Naming
  11 import ExprNodes
  12 import Nodes
  13 import Options
  14 import Builtin
  15
  16 from Cython.Compiler.Visitor import VisitorTransform, TreeVisitor
  17 from Cython.Compiler.Visitor import CythonTransform, EnvTransform, ScopeTrackingTransform
  18 from Cython.Compiler.ModuleNode import ModuleNode
  19 from Cython.Compiler.UtilNodes import LetNode, LetRefNode, ResultRefNode
  20 from Cython.Compiler.TreeFragment import TreeFragment, TemplateTransform
  21 from Cython.Compiler.StringEncoding import EncodedString
  22 from Cython.Compiler.Errors import error, warning, CompileError, InternalError
  23
  24 import copy
  25
  26
  27 class NameNodeCollector(TreeVisitor):
  28     """Collect all NameNodes of a (sub-)tree in the ``name_nodes``
  29     attribute.
  30     """
  31     def __init__(self):
  32         super(NameNodeCollector, self).__init__()
  33         self.name_nodes = []
  34
  35     def visit_NameNode(self, node):
  36         self.name_nodes.append(node)
  37
  38     def visit_Node(self, node):
  39         self._visitchildren(node, None)
  40
  41
  42 class SkipDeclarations(object):
  43     """
  44     Variable and function declarations can often have a deep tree structure,
  45     and yet most transformations don't need to descend to this depth.
  46
  47     Declaration nodes are removed after AnalyseDeclarationsTransform, so there
  48     is no need to use this for transformations after that point.
  49     """
  50     def visit_CTypeDefNode(self, node):
  51         return node
  52
  53     def visit_CVarDefNode(self, node):
  54         return node
  55
  56     def visit_CDeclaratorNode(self, node):
  57         return node
  58
  59     def visit_CBaseTypeNode(self, node):
  60         return node
  61
  62     def visit_CEnumDefNode(self, node):
  63         return node
  64
  65     def visit_CStructOrUnionDefNode(self, node):
  66         return node
  67
  68 class NormalizeTree(CythonTransform):
  69     """
  70     This transform fixes up a few things after parsing
  71     in order to make the parse tree more suitable for
  72     transforms.
  73
  74     a) After parsing, blocks with only one statement will
  75     be represented by that statement, not by a StatListNode.
  76     When doing transforms this is annoying and inconsistent,
  77     as one cannot in general remove a statement in a consistent
  78     way and so on. This transform wraps any single statements
  79     in a StatListNode containing a single statement.
  80
  81     b) The PassStatNode is a noop and serves no purpose beyond
  82     plugging such one-statement blocks; i.e., once parsed a
  83 `    "pass" can just as well be represented using an empty
  84     StatListNode. This means less special cases to worry about
  85     in subsequent transforms (one always checks to see if a
  86     StatListNode has no children to see if the block is empty).
  87     """
  88
  89     def __init__(self, context):
  90         super(NormalizeTree, self).__init__(context)
  91         self.is_in_statlist = False
  92         self.is_in_expr = False
  93
  94     def visit_ExprNode(self, node):
  95         stacktmp = self.is_in_expr
  96         self.is_in_expr = True
  97         self.visitchildren(node)
  98         self.is_in_expr = stacktmp
  99         return node
 100
 101     def visit_StatNode(self, node, is_listcontainer=False):
 102         stacktmp = self.is_in_statlist
 103         self.is_in_statlist = is_listcontainer
 104         self.visitchildren(node)
 105         self.is_in_statlist = stacktmp
 106         if not self.is_in_statlist and not self.is_in_expr:
 107             return Nodes.StatListNode(pos=node.pos, stats=[node])
 108         else:
 109             return node
 110
 111     def visit_StatListNode(self, node):
 112         self.is_in_statlist = True
 113         self.visitchildren(node)
 114         self.is_in_statlist = False
 115         return node
 116
 117     def visit_ParallelAssignmentNode(self, node):
 118         return self.visit_StatNode(node, True)
 119
 120     def visit_CEnumDefNode(self, node):
 121         return self.visit_StatNode(node, True)
 122
 123     def visit_CStructOrUnionDefNode(self, node):
 124         return self.visit_StatNode(node, True)
 125
 126     # Eliminate PassStatNode
 127     def visit_PassStatNode(self, node):
 128         if not self.is_in_statlist:
 129             return Nodes.StatListNode(pos=node.pos, stats=[])
 130         else:
 131             return []
 132
 133     def visit_CDeclaratorNode(self, node):
 134         return node
 135
 136
 137 class PostParseError(CompileError): pass
 138
 139 # error strings checked by unit tests, so define them
 140 ERR_CDEF_INCLASS = 'Cannot assign default value to fields in cdef classes, structs or unions'
 141 ERR_BUF_DEFAULTS = 'Invalid buffer defaults specification (see docs)'
 142 ERR_INVALID_SPECIALATTR_TYPE = 'Special attributes must not have a type declared'
 143 class PostParse(ScopeTrackingTransform):
 144     """
 145     Basic interpretation of the parse tree, as well as validity
 146     checking that can be done on a very basic level on the parse
 147     tree (while still not being a problem with the basic syntax,
 148     as such).
 149
 150     Specifically:
 151     - Default values to cdef assignments are turned into single
 152     assignments following the declaration (everywhere but in class
 153     bodies, where they raise a compile error)
 154
 155     - Interpret some node structures into Python runtime values.
 156     Some nodes take compile-time arguments (currently:
 157     TemplatedTypeNode[args] and __cythonbufferdefaults__ = {args}),
 158     which should be interpreted. This happens in a general way
 159     and other steps should be taken to ensure validity.
 160
 161     Type arguments cannot be interpreted in this way.
 162
 163     - For __cythonbufferdefaults__ the arguments are checked for
 164     validity.
 165
 166     TemplatedTypeNode has its directives interpreted:
 167     Any first positional argument goes into the "dtype" attribute,
 168     any "ndim" keyword argument goes into the "ndim" attribute and
 169     so on. Also it is checked that the directive combination is valid.
 170     - __cythonbufferdefaults__ attributes are parsed and put into the
 171     type information.
 172
 173     Note: Currently Parsing.py does a lot of interpretation and
 174     reorganization that can be refactored into this transform
 175     if a more pure Abstract Syntax Tree is wanted.
 176     """
 177
 178     def __init__(self, context):
 179         super(PostParse, self).__init__(context)
 180         self.specialattribute_handlers = {
 181             '__cythonbufferdefaults__' : self.handle_bufferdefaults
 182         }
 183
 184     def visit_ModuleNode(self, node):
 185         self.lambda_counter = 1
 186         self.genexpr_counter = 1
 187         return super(PostParse, self).visit_ModuleNode(node)
 188
 189     def visit_LambdaNode(self, node):
 190         # unpack a lambda expression into the corresponding DefNode
 191         lambda_id = self.lambda_counter
 192         self.lambda_counter += 1
 193         node.lambda_name = EncodedString(u'lambda%d' % lambda_id)
 194         collector = YieldNodeCollector()
 195         collector.visitchildren(node.result_expr)
 196         if collector.yields or isinstance(node.result_expr, ExprNodes.YieldExprNode):
 197             body = Nodes.ExprStatNode(
 198                 node.result_expr.pos, expr=node.result_expr)
 199         else:
 200             body = Nodes.ReturnStatNode(
 201                 node.result_expr.pos, value=node.result_expr)
 202         node.def_node = Nodes.DefNode(
 203             node.pos, name=node.name, lambda_name=node.lambda_name,
 204             args=node.args, star_arg=node.star_arg,
 205             starstar_arg=node.starstar_arg,
 206             body=body, doc=None)
 207         self.visitchildren(node)
 208         return node
 209
 210     def visit_GeneratorExpressionNode(self, node):
 211         # unpack a generator expression into the corresponding DefNode
 212         genexpr_id = self.genexpr_counter
 213         self.genexpr_counter += 1
 214         node.genexpr_name = EncodedString(u'genexpr%d' % genexpr_id)
 215
 216         node.def_node = Nodes.DefNode(node.pos, name=node.name,
 217                                       doc=None,
 218                                       args=[], star_arg=None,
 219                                       starstar_arg=None,
 220                                       body=node.loop)
 221         self.visitchildren(node)
 222         return node
 223
 224     # cdef variables
 225     def handle_bufferdefaults(self, decl):
 226         if not isinstance(decl.default, ExprNodes.DictNode):
 227             raise PostParseError(decl.pos, ERR_BUF_DEFAULTS)
 228         self.scope_node.buffer_defaults_node = decl.default
 229         self.scope_node.buffer_defaults_pos = decl.pos
 230
 231     def visit_CVarDefNode(self, node):
 232         # This assumes only plain names and pointers are assignable on
 233         # declaration. Also, it makes use of the fact that a cdef decl
 234         # must appear before the first use, so we don't have to deal with
 235         # "i = 3; cdef int i = i" and can simply move the nodes around.
 236         try:
 237             self.visitchildren(node)
 238             stats = [node]
 239             newdecls = []
 240             for decl in node.declarators:
 241                 declbase = decl
 242                 while isinstance(declbase, Nodes.CPtrDeclaratorNode):
 243                     declbase = declbase.base
 244                 if isinstance(declbase, Nodes.CNameDeclaratorNode):
 245                     if declbase.default is not None:
 246                         if self.scope_type in ('cclass', 'pyclass', 'struct'):
 247                             if isinstance(self.scope_node, Nodes.CClassDefNode):
 248                                 handler = self.specialattribute_handlers.get(decl.name)
 249                                 if handler:
 250                                     if decl is not declbase:
 251                                         raise PostParseError(decl.pos, ERR_INVALID_SPECIALATTR_TYPE)
 252                                     handler(decl)
 253                                     continue # Remove declaration
 254                             raise PostParseError(decl.pos, ERR_CDEF_INCLASS)
 255                         first_assignment = self.scope_type != 'module'
 256                         stats.append(Nodes.SingleAssignmentNode(node.pos,
 257                             lhs=ExprNodes.NameNode(node.pos, name=declbase.name),
 258                             rhs=declbase.default, first=first_assignment))
 259                         declbase.default = None
 260                 newdecls.append(decl)
 261             node.declarators = newdecls
 262             return stats
 263         except PostParseError, e:
 264             # An error in a cdef clause is ok, simply remove the declaration
 265             # and try to move on to report more errors
 266             self.context.nonfatal_error(e)
 267             return None
 268
 269     # Split parallel assignments (a,b = b,a) into separate partial
 270     # assignments that are executed rhs-first using temps.  This
 271     # restructuring must be applied before type analysis so that known
 272     # types on rhs and lhs can be matched directly.  It is required in
 273     # the case that the types cannot be coerced to a Python type in
 274     # order to assign from a tuple.
 275
 276     def visit_SingleAssignmentNode(self, node):
 277         self.visitchildren(node)
 278         return self._visit_assignment_node(node, [node.lhs, node.rhs])
 279
 280     def visit_CascadedAssignmentNode(self, node):
 281         self.visitchildren(node)
 282         return self._visit_assignment_node(node, node.lhs_list + [node.rhs])
 283
 284     def _visit_assignment_node(self, node, expr_list):
 285         """Flatten parallel assignments into separate single
 286         assignments or cascaded assignments.
 287         """
 288         if sum([ 1 for expr in expr_list if expr.is_sequence_constructor ]) < 2:
 289             # no parallel assignments => nothing to do
 290             return node
 291
 292         expr_list_list = []
 293         flatten_parallel_assignments(expr_list, expr_list_list)
 294         temp_refs = []
 295         eliminate_rhs_duplicates(expr_list_list, temp_refs)
 296
 297         nodes = []
 298         for expr_list in expr_list_list:
 299             lhs_list = expr_list[:-1]
 300             rhs = expr_list[-1]
 301             if len(lhs_list) == 1:
 302                 node = Nodes.SingleAssignmentNode(rhs.pos,
 303                     lhs = lhs_list[0], rhs = rhs)
 304             else:
 305                 node = Nodes.CascadedAssignmentNode(rhs.pos,
 306                     lhs_list = lhs_list, rhs = rhs)
 307             nodes.append(node)
 308
 309         if len(nodes) == 1:
 310             assign_node = nodes[0]
 311         else:
 312             assign_node = Nodes.ParallelAssignmentNode(nodes[0].pos, stats = nodes)
 313
 314         if temp_refs:
 315             duplicates_and_temps = [ (temp.expression, temp)
 316                                      for temp in temp_refs ]
 317             sort_common_subsequences(duplicates_and_temps)
 318             for _, temp_ref in duplicates_and_temps[::-1]:
 319                 assign_node = LetNode(temp_ref, assign_node)
 320
 321         return assign_node
 322
 323     def _flatten_sequence(self, seq, result):
 324         for arg in seq.args:
 325             if arg.is_sequence_constructor:
 326                 self._flatten_sequence(arg, result)
 327             else:
 328                 result.append(arg)
 329         return result
 330
 331     def visit_DelStatNode(self, node):
 332         self.visitchildren(node)
 333         node.args = self._flatten_sequence(node, [])
 334         return node
 335
 336
 337 def eliminate_rhs_duplicates(expr_list_list, ref_node_sequence):
 338     """Replace rhs items by LetRefNodes if they appear more than once.
 339     Creates a sequence of LetRefNodes that set up the required temps
 340     and appends them to ref_node_sequence.  The input list is modified
 341     in-place.
 342     """
 343     seen_nodes = cython.set()
 344     ref_nodes = {}
 345     def find_duplicates(node):
 346         if node.is_literal or node.is_name:
 347             # no need to replace those; can't include attributes here
 348             # as their access is not necessarily side-effect free
 349             return
 350         if node in seen_nodes:
 351             if node not in ref_nodes:
 352                 ref_node = LetRefNode(node)
 353                 ref_nodes[node] = ref_node
 354                 ref_node_sequence.append(ref_node)
 355         else:
 356             seen_nodes.add(node)
 357             if node.is_sequence_constructor:
 358                 for item in node.args:
 359                     find_duplicates(item)
 360
 361     for expr_list in expr_list_list:
 362         rhs = expr_list[-1]
 363         find_duplicates(rhs)
 364     if not ref_nodes:
 365         return
 366
 367     def substitute_nodes(node):
 368         if node in ref_nodes:
 369             return ref_nodes[node]
 370         elif node.is_sequence_constructor:
 371             node.args = list(map(substitute_nodes, node.args))
 372         return node
 373
 374     # replace nodes inside of the common subexpressions
 375     for node in ref_nodes:
 376         if node.is_sequence_constructor:
 377             node.args = list(map(substitute_nodes, node.args))
 378
 379     # replace common subexpressions on all rhs items
 380     for expr_list in expr_list_list:
 381         expr_list[-1] = substitute_nodes(expr_list[-1])
 382
 383 def sort_common_subsequences(items):
 384     """Sort items/subsequences so that all items and subsequences that
 385     an item contains appear before the item itself.  This is needed
 386     because each rhs item must only be evaluated once, so its value
 387     must be evaluated first and then reused when packing sequences
 388     that contain it.
 389
 390     This implies a partial order, and the sort must be stable to
 391     preserve the original order as much as possible, so we use a
 392     simple insertion sort (which is very fast for short sequences, the
 393     normal case in practice).
 394     """
 395     def contains(seq, x):
 396         for item in seq:
 397             if item is x:
 398                 return True
 399             elif item.is_sequence_constructor and contains(item.args, x):
 400                 return True
 401         return False
 402     def lower_than(a,b):
 403         return b.is_sequence_constructor and contains(b.args, a)
 404
 405     for pos, item in enumerate(items):
 406         key = item[1] # the ResultRefNode which has already been injected into the sequences
 407         new_pos = pos
 408         for i in xrange(pos-1, -1, -1):
 409             if lower_than(key, items[i][0]):
 410                 new_pos = i
 411         if new_pos != pos:
 412             for i in xrange(pos, new_pos, -1):
 413                 items[i] = items[i-1]
 414             items[new_pos] = item
 415
 416 def flatten_parallel_assignments(input, output):
 417     #  The input is a list of expression nodes, representing the LHSs
 418     #  and RHS of one (possibly cascaded) assignment statement.  For
 419     #  sequence constructors, rearranges the matching parts of both
 420     #  sides into a list of equivalent assignments between the
 421     #  individual elements.  This transformation is applied
 422     #  recursively, so that nested structures get matched as well.
 423     rhs = input[-1]
 424     if not rhs.is_sequence_constructor or not sum([lhs.is_sequence_constructor for lhs in input[:-1]]):
 425         output.append(input)
 426         return
 427
 428     complete_assignments = []
 429
 430     rhs_size = len(rhs.args)
 431     lhs_targets = [ [] for _ in xrange(rhs_size) ]
 432     starred_assignments = []
 433     for lhs in input[:-1]:
 434         if not lhs.is_sequence_constructor:
 435             if lhs.is_starred:
 436                 error(lhs.pos, "starred assignment target must be in a list or tuple")
 437             complete_assignments.append(lhs)
 438             continue
 439         lhs_size = len(lhs.args)
 440         starred_targets = sum([1 for expr in lhs.args if expr.is_starred])
 441         if starred_targets > 1:
 442             error(lhs.pos, "more than 1 starred expression in assignment")
 443             output.append([lhs,rhs])
 444             continue
 445         elif lhs_size - starred_targets > rhs_size:
 446             error(lhs.pos, "need more than %d value%s to unpack"
 447                   % (rhs_size, (rhs_size != 1) and 's' or ''))
 448             output.append([lhs,rhs])
 449             continue
 450         elif starred_targets:
 451             map_starred_assignment(lhs_targets, starred_assignments,
 452                                    lhs.args, rhs.args)
 453         elif lhs_size < rhs_size:
 454             error(lhs.pos, "too many values to unpack (expected %d, got %d)"
 455                   % (lhs_size, rhs_size))
 456             output.append([lhs,rhs])
 457             continue
 458         else:
 459             for targets, expr in zip(lhs_targets, lhs.args):
 460                 targets.append(expr)
 461
 462     if complete_assignments:
 463         complete_assignments.append(rhs)
 464         output.append(complete_assignments)
 465
 466     # recursively flatten partial assignments
 467     for cascade, rhs in zip(lhs_targets, rhs.args):
 468         if cascade:
 469             cascade.append(rhs)
 470             flatten_parallel_assignments(cascade, output)
 471
 472     # recursively flatten starred assignments
 473     for cascade in starred_assignments:
 474         if cascade[0].is_sequence_constructor:
 475             flatten_parallel_assignments(cascade, output)
 476         else:
 477             output.append(cascade)
 478
 479 def map_starred_assignment(lhs_targets, starred_assignments, lhs_args, rhs_args):
 480     # Appends the fixed-position LHS targets to the target list that
 481     # appear left and right of the starred argument.
 482     #
 483     # The starred_assignments list receives a new tuple
 484     # (lhs_target, rhs_values_list) that maps the remaining arguments
 485     # (those that match the starred target) to a list.
 486
 487     # left side of the starred target
 488     for i, (targets, expr) in enumerate(zip(lhs_targets, lhs_args)):
 489         if expr.is_starred:
 490             starred = i
 491             lhs_remaining = len(lhs_args) - i - 1
 492             break
 493         targets.append(expr)
 494     else:
 495         raise InternalError("no starred arg found when splitting starred assignment")
 496
 497     # right side of the starred target
 498     for i, (targets, expr) in enumerate(zip(lhs_targets[-lhs_remaining:],
 499                                             lhs_args[starred + 1:])):
 500         targets.append(expr)
 501
 502     # the starred target itself, must be assigned a (potentially empty) list
 503     target = lhs_args[starred].target # unpack starred node
 504     starred_rhs = rhs_args[starred:]
 505     if lhs_remaining:
 506         starred_rhs = starred_rhs[:-lhs_remaining]
 507     if starred_rhs:
 508         pos = starred_rhs[0].pos
 509     else:
 510         pos = target.pos
 511     starred_assignments.append([
 512         target, ExprNodes.ListNode(pos=pos, args=starred_rhs)])
 513
 514
 515 class PxdPostParse(CythonTransform, SkipDeclarations):
 516     """
 517     Basic interpretation/validity checking that should only be
 518     done on pxd trees.
 519
 520     A lot of this checking currently happens in the parser; but
 521     what is listed below happens here.
 522
 523     - "def" functions are let through only if they fill the
 524     getbuffer/releasebuffer slots
 525
 526     - cdef functions are let through only if they are on the
 527     top level and are declared "inline"
 528     """
 529     ERR_INLINE_ONLY = "function definition in pxd file must be declared 'cdef inline'"
 530     ERR_NOGO_WITH_INLINE = "inline function definition in pxd file cannot be '%s'"
 531
 532     def __call__(self, node):
 533         self.scope_type = 'pxd'
 534         return super(PxdPostParse, self).__call__(node)
 535
 536     def visit_CClassDefNode(self, node):
 537         old = self.scope_type
 538         self.scope_type = 'cclass'
 539         self.visitchildren(node)
 540         self.scope_type = old
 541         return node
 542
 543     def visit_FuncDefNode(self, node):
 544         # FuncDefNode always come with an implementation (without
 545         # an imp they are CVarDefNodes..)
 546         err = self.ERR_INLINE_ONLY
 547
 548         if (isinstance(node, Nodes.DefNode) and self.scope_type == 'cclass'
 549             and node.name in ('__getbuffer__', '__releasebuffer__')):
 550             err = None # allow these slots
 551
 552         if isinstance(node, Nodes.CFuncDefNode):
 553             if u'inline' in node.modifiers and self.scope_type == 'pxd':
 554                 node.inline_in_pxd = True
 555                 if node.visibility != 'private':
 556                     err = self.ERR_NOGO_WITH_INLINE % node.visibility
 557                 elif node.api:
 558                     err = self.ERR_NOGO_WITH_INLINE % 'api'
 559                 else:
 560                     err = None # allow inline function
 561             else:
 562                 err = self.ERR_INLINE_ONLY
 563
 564         if err:
 565             self.context.nonfatal_error(PostParseError(node.pos, err))
 566             return None
 567         else:
 568             return node
 569
 570 class InterpretCompilerDirectives(CythonTransform, SkipDeclarations):
 571     """
 572     After parsing, directives can be stored in a number of places:
 573     - #cython-comments at the top of the file (stored in ModuleNode)
 574     - Command-line arguments overriding these
 575     - @cython.directivename decorators
 576     - with cython.directivename: statements
 577
 578     This transform is responsible for interpreting these various sources
 579     and store the directive in two ways:
 580     - Set the directives attribute of the ModuleNode for global directives.
 581     - Use a CompilerDirectivesNode to override directives for a subtree.
 582
 583     (The first one is primarily to not have to modify with the tree
 584     structure, so that ModuleNode stay on top.)
 585
 586     The directives are stored in dictionaries from name to value in effect.
 587     Each such dictionary is always filled in for all possible directives,
 588     using default values where no value is given by the user.
 589
 590     The available directives are controlled in Options.py.
 591
 592     Note that we have to run this prior to analysis, and so some minor
 593     duplication of functionality has to occur: We manually track cimports
 594     and which names the "cython" module may have been imported to.
 595     """
 596     unop_method_nodes = {
 597         'typeof': ExprNodes.TypeofNode,
 598
 599         'operator.address': ExprNodes.AmpersandNode,
 600         'operator.dereference': ExprNodes.DereferenceNode,
 601         'operator.preincrement' : ExprNodes.inc_dec_constructor(True, '++'),
 602         'operator.predecrement' : ExprNodes.inc_dec_constructor(True, '--'),
 603         'operator.postincrement': ExprNodes.inc_dec_constructor(False, '++'),
 604         'operator.postdecrement': ExprNodes.inc_dec_constructor(False, '--'),
 605
 606         # For backwards compatability.
 607         'address': ExprNodes.AmpersandNode,
 608     }
 609
 610     binop_method_nodes = {
 611         'operator.comma'        : ExprNodes.c_binop_constructor(','),
 612     }
 613
 614     special_methods = cython.set(['declare', 'union', 'struct', 'typedef', 'sizeof',
 615                                   'cast', 'pointer', 'compiled', 'NULL'])
 616     special_methods.update(unop_method_nodes.keys())
 617
 618     def __init__(self, context, compilation_directive_defaults):
 619         super(InterpretCompilerDirectives, self).__init__(context)
 620         self.compilation_directive_defaults = {}
 621         for key, value in compilation_directive_defaults.items():
 622             self.compilation_directive_defaults[unicode(key)] = copy.deepcopy(value)
 623         self.cython_module_names = cython.set()
 624         self.directive_names = {}
 625
 626     def check_directive_scope(self, pos, directive, scope):
 627         legal_scopes = Options.directive_scopes.get(directive, None)
 628         if legal_scopes and scope not in legal_scopes:
 629             self.context.nonfatal_error(PostParseError(pos, 'The %s compiler directive '
 630                                         'is not allowed in %s scope' % (directive, scope)))
 631             return False
 632         else:
 633             return True
 634
 635     # Set up processing and handle the cython: comments.
 636     def visit_ModuleNode(self, node):
 637         for key, value in node.directive_comments.items():
 638             if not self.check_directive_scope(node.pos, key, 'module'):
 639                 self.wrong_scope_error(node.pos, key, 'module')
 640                 del node.directive_comments[key]
 641
 642         directives = copy.deepcopy(Options.directive_defaults)
 643         directives.update(copy.deepcopy(self.compilation_directive_defaults))
 644         directives.update(node.directive_comments)
 645         self.directives = directives
 646         node.directives = directives
 647         self.visitchildren(node)
 648         node.cython_module_names = self.cython_module_names
 649         return node
 650
 651     # The following four functions track imports and cimports that
 652     # begin with "cython"
 653     def is_cython_directive(self, name):
 654         return (name in Options.directive_types or
 655                 name in self.special_methods or
 656                 PyrexTypes.parse_basic_type(name))
 657
 658     def visit_CImportStatNode(self, node):
 659         if node.module_name == u"cython":
 660             self.cython_module_names.add(node.as_name or u"cython")
 661         elif node.module_name.startswith(u"cython."):
 662             if node.as_name:
 663                 self.directive_names[node.as_name] = node.module_name[7:]
 664             else:
 665                 self.cython_module_names.add(u"cython")
 666             # if this cimport was a compiler directive, we don't
 667             # want to leave the cimport node sitting in the tree
 668             return None
 669         return node
 670
 671     def visit_FromCImportStatNode(self, node):
 672         if (node.module_name == u"cython") or \
 673                node.module_name.startswith(u"cython."):
 674             submodule = (node.module_name + u".")[7:]
 675             newimp = []
 676             for pos, name, as_name, kind in node.imported_names:
 677                 full_name = submodule + name
 678                 if self.is_cython_directive(full_name):
 679                     if as_name is None:
 680                         as_name = full_name
 681                     self.directive_names[as_name] = full_name
 682                     if kind is not None:
 683                         self.context.nonfatal_error(PostParseError(pos,
 684                             "Compiler directive imports must be plain imports"))
 685                 else:
 686                     newimp.append((pos, name, as_name, kind))
 687             if not newimp:
 688                 return None
 689             node.imported_names = newimp
 690         return node
 691
 692     def visit_FromImportStatNode(self, node):
 693         if (node.module.module_name.value == u"cython") or \
 694                node.module.module_name.value.startswith(u"cython."):
 695             submodule = (node.module.module_name.value + u".")[7:]
 696             newimp = []
 697             for name, name_node in node.items:
 698                 full_name = submodule + name
 699                 if self.is_cython_directive(full_name):
 700                     self.directive_names[name_node.name] = full_name
 701                 else:
 702                     newimp.append((name, name_node))
 703             if not newimp:
 704                 return None
 705             node.items = newimp
 706         return node
 707
 708     def visit_SingleAssignmentNode(self, node):
 709         if (isinstance(node.rhs, ExprNodes.ImportNode) and
 710                 node.rhs.module_name.value == u'cython'):
 711             node = Nodes.CImportStatNode(node.pos,
 712                                          module_name = u'cython',
 713                                          as_name = node.lhs.name)
 714             self.visit_CImportStatNode(node)
 715         else:
 716             self.visitchildren(node)
 717         return node
 718
 719     def visit_NameNode(self, node):
 720         if node.name in self.cython_module_names:
 721             node.is_cython_module = True
 722         else:
 723             node.cython_attribute = self.directive_names.get(node.name)
 724         return node
 725
 726     def try_to_parse_directives(self, node):
 727         # If node is the contents of an directive (in a with statement or
 728         # decorator), returns a list of (directivename, value) pairs.
 729         # Otherwise, returns None
 730         if isinstance(node, ExprNodes.CallNode):
 731             self.visit(node.function)
 732             optname = node.function.as_cython_attribute()
 733             if optname:
 734                 directivetype = Options.directive_types.get(optname)
 735                 if directivetype:
 736                     args, kwds = node.explicit_args_kwds()
 737                     directives = []
 738                     key_value_pairs = []
 739                     if kwds is not None and directivetype is not dict:
 740                         for keyvalue in kwds.key_value_pairs:
 741                             key, value = keyvalue
 742                             sub_optname = "%s.%s" % (optname, key.value)
 743                             if Options.directive_types.get(sub_optname):
 744                                 directives.append(self.try_to_parse_directive(sub_optname, [value], None, keyvalue.pos))
 745                             else:
 746                                 key_value_pairs.append(keyvalue)
 747                         if not key_value_pairs:
 748                             kwds = None
 749                         else:
 750                             kwds.key_value_pairs = key_value_pairs
 751                         if directives and not kwds and not args:
 752                             return directives
 753                     directives.append(self.try_to_parse_directive(optname, args, kwds, node.function.pos))
 754                     return directives
 755         elif isinstance(node, (ExprNodes.AttributeNode, ExprNodes.NameNode)):
 756             self.visit(node)
 757             optname = node.as_cython_attribute()
 758             if optname:
 759                 directivetype = Options.directive_types.get(optname)
 760                 if directivetype is bool:
 761                     return [(optname, True)]
 762                 elif directivetype is None:
 763                     return [(optname, None)]
 764                 else:
 765                     raise PostParseError(
 766                         node.pos, "The '%s' directive should be used as a function call." % optname)
 767         return None
 768
 769     def try_to_parse_directive(self, optname, args, kwds, pos):
 770         directivetype = Options.directive_types.get(optname)
 771         if len(args) == 1 and isinstance(args[0], ExprNodes.NoneNode):
 772             return optname, Options.directive_defaults[optname]
 773         elif directivetype is bool:
 774             if kwds is not None or len(args) != 1 or not isinstance(args[0], ExprNodes.BoolNode):
 775                 raise PostParseError(pos,
 776                     'The %s directive takes one compile-time boolean argument' % optname)
 777             return (optname, args[0].value)
 778         elif directivetype is str:
 779             if kwds is not None or len(args) != 1 or not isinstance(args[0], (ExprNodes.StringNode,
 780                                                                               ExprNodes.UnicodeNode)):
 781                 raise PostParseError(pos,
 782                     'The %s directive takes one compile-time string argument' % optname)
 783             return (optname, str(args[0].value))
 784         elif directivetype is dict:
 785             if len(args) != 0:
 786                 raise PostParseError(pos,
 787                     'The %s directive takes no prepositional arguments' % optname)
 788             return optname, dict([(key.value, value) for key, value in kwds.key_value_pairs])
 789         elif directivetype is list:
 790             if kwds and len(kwds) != 0:
 791                 raise PostParseError(pos,
 792                     'The %s directive takes no keyword arguments' % optname)
 793             return optname, [ str(arg.value) for arg in args ]
 794         else:
 795             assert False
 796
 797     def visit_with_directives(self, body, directives):
 798         olddirectives = self.directives
 799         newdirectives = copy.copy(olddirectives)
 800         newdirectives.update(directives)
 801         self.directives = newdirectives
 802         assert isinstance(body, Nodes.StatListNode), body
 803         retbody = self.visit_Node(body)
 804         directive = Nodes.CompilerDirectivesNode(pos=retbody.pos, body=retbody,
 805                                                  directives=newdirectives)
 806         self.directives = olddirectives
 807         return directive
 808
 809     # Handle decorators
 810     def visit_FuncDefNode(self, node):
 811         directives = self._extract_directives(node, 'function')
 812         if not directives:
 813             return self.visit_Node(node)
 814         body = Nodes.StatListNode(node.pos, stats=[node])
 815         return self.visit_with_directives(body, directives)
 816
 817     def visit_CVarDefNode(self, node):
 818         if not node.decorators:
 819             return node
 820         for dec in node.decorators:
 821             for directive in self.try_to_parse_directives(dec.decorator) or ():
 822                 if directive is not None and directive[0] == u'locals':
 823                     node.directive_locals = directive[1]
 824                 else:
 825                     self.context.nonfatal_error(PostParseError(dec.pos,
 826                         "Cdef functions can only take cython.locals() decorator."))
 827         return node
 828
 829     def visit_CClassDefNode(self, node):
 830         directives = self._extract_directives(node, 'cclass')
 831         if not directives:
 832             return self.visit_Node(node)
 833         body = Nodes.StatListNode(node.pos, stats=[node])
 834         return self.visit_with_directives(body, directives)
 835
 836     def visit_PyClassDefNode(self, node):
 837         directives = self._extract_directives(node, 'class')
 838         if not directives:
 839             return self.visit_Node(node)
 840         body = Nodes.StatListNode(node.pos, stats=[node])
 841         return self.visit_with_directives(body, directives)
 842
 843     def _extract_directives(self, node, scope_name):
 844         if not node.decorators:
 845             return {}
 846         # Split the decorators into two lists -- real decorators and directives
 847         directives = []
 848         realdecs = []
 849         for dec in node.decorators:
 850             new_directives = self.try_to_parse_directives(dec.decorator)
 851             if new_directives is not None:
 852                 for directive in new_directives:
 853                     if self.check_directive_scope(node.pos, directive[0], scope_name):
 854                         directives.append(directive)
 855             else:
 856                 realdecs.append(dec)
 857         if realdecs and isinstance(node, (Nodes.CFuncDefNode, Nodes.CClassDefNode)):
 858             raise PostParseError(realdecs[0].pos, "Cdef functions/classes cannot take arbitrary decorators.")
 859         else:
 860             node.decorators = realdecs
 861         # merge or override repeated directives
 862         optdict = {}
 863         directives.reverse() # Decorators coming first take precedence
 864         for directive in directives:
 865             name, value = directive
 866             if name in optdict:
 867                 old_value = optdict[name]
 868                 # keywords and arg lists can be merged, everything
 869                 # else overrides completely
 870                 if isinstance(old_value, dict):
 871                     old_value.update(value)
 872                 elif isinstance(old_value, list):
 873                     old_value.extend(value)
 874                 else:
 875                     optdict[name] = value
 876             else:
 877                 optdict[name] = value
 878         return optdict
 879
 880     # Handle with statements
 881     def visit_WithStatNode(self, node):
 882         directive_dict = {}
 883         for directive in self.try_to_parse_directives(node.manager) or []:
 884             if directive is not None:
 885                 if node.target is not None:
 886                     self.context.nonfatal_error(
 887                         PostParseError(node.pos, "Compiler directive with statements cannot contain 'as'"))
 888                 else:
 889                     name, value = directive
 890                     if name == 'nogil':
 891                         # special case: in pure mode, "with nogil" spells "with cython.nogil"
 892                         node = Nodes.GILStatNode(node.pos, state = "nogil", body = node.body)
 893                         return self.visit_Node(node)
 894                     if self.check_directive_scope(node.pos, name, 'with statement'):
 895                         directive_dict[name] = value
 896         if directive_dict:
 897             return self.visit_with_directives(node.body, directive_dict)
 898         return self.visit_Node(node)
 899
 900
 901 class DecoratorTransform(CythonTransform, SkipDeclarations):
 902
 903     def visit_DefNode(self, func_node):
 904         self.visitchildren(func_node)
 905         if not func_node.decorators:
 906             return func_node
 907         return self._handle_decorators(
 908             func_node, func_node.name)
 909
 910     def visit_CClassDefNode(self, class_node):
 911         # This doesn't currently work, so it's disabled.
 912         #
 913         # Problem: assignments to cdef class names do not work.  They
 914         # would require an additional check anyway, as the extension
 915         # type must not change its C type, so decorators cannot
 916         # replace an extension type, just alter it and return it.
 917
 918         self.visitchildren(class_node)
 919         if not class_node.decorators:
 920             return class_node
 921         error(class_node.pos,
 922               "Decorators not allowed on cdef classes (used on type '%s')" % class_node.class_name)
 923         return class_node
 924         #return self._handle_decorators(
 925         #    class_node, class_node.class_name)
 926
 927     def visit_ClassDefNode(self, class_node):
 928         self.visitchildren(class_node)
 929         if not class_node.decorators:
 930             return class_node
 931         return self._handle_decorators(
 932             class_node, class_node.name)
 933
 934     def _handle_decorators(self, node, name):
 935         decorator_result = ExprNodes.NameNode(node.pos, name = name)
 936         for decorator in node.decorators[::-1]:
 937             decorator_result = ExprNodes.SimpleCallNode(
 938                 decorator.pos,
 939                 function = decorator.decorator,
 940                 args = [decorator_result])
 941
 942         name_node = ExprNodes.NameNode(node.pos, name = name)
 943         reassignment = Nodes.SingleAssignmentNode(
 944             node.pos,
 945             lhs = name_node,
 946             rhs = decorator_result)
 947         return [node, reassignment]
 948
 949
 950 class AnalyseDeclarationsTransform(CythonTransform):
 951
 952     basic_property = TreeFragment(u"""
 953 property NAME:
 954     def __get__(self):
 955         return ATTR
 956     def __set__(self, value):
 957         ATTR = value
 958     """, level='c_class')
 959     basic_pyobject_property = TreeFragment(u"""
 960 property NAME:
 961     def __get__(self):
 962         return ATTR
 963     def __set__(self, value):
 964         ATTR = value
 965     def __del__(self):
 966         ATTR = None
 967     """, level='c_class')
 968     basic_property_ro = TreeFragment(u"""
 969 property NAME:
 970     def __get__(self):
 971         return ATTR
 972     """, level='c_class')
 973
 974     struct_or_union_wrapper = TreeFragment(u"""
 975 cdef class NAME:
 976     cdef TYPE value
 977     def __init__(self, MEMBER=None):
 978         cdef int count
 979         count = 0
 980         INIT_ASSIGNMENTS
 981         if IS_UNION and count > 1:
 982             raise ValueError, "At most one union member should be specified."
 983     def __str__(self):
 984         return STR_FORMAT % MEMBER_TUPLE
 985     def __repr__(self):
 986         return REPR_FORMAT % MEMBER_TUPLE
 987     """)
 988
 989     init_assignment = TreeFragment(u"""
 990 if VALUE is not None:
 991     ATTR = VALUE
 992     count += 1
 993     """)
 994
 995     def __call__(self, root):
 996         self.env_stack = [root.scope]
 997         # needed to determine if a cdef var is declared after it's used.
 998         self.seen_vars_stack = []
 999         return super(AnalyseDeclarationsTransform, self).__call__(root)
1000
1001     def visit_NameNode(self, node):
1002         self.seen_vars_stack[-1].add(node.name)
1003         return node
1004
1005     def visit_ModuleNode(self, node):
1006         self.seen_vars_stack.append(cython.set())
1007         node.analyse_declarations(self.env_stack[-1])
1008         self.visitchildren(node)
1009         self.seen_vars_stack.pop()
1010         return node
1011
1012     def visit_LambdaNode(self, node):
1013         node.analyse_declarations(self.env_stack[-1])
1014         self.visitchildren(node)
1015         return node
1016
1017     def visit_ClassDefNode(self, node):
1018         self.env_stack.append(node.scope)
1019         self.visitchildren(node)
1020         self.env_stack.pop()
1021         return node
1022
1023     def visit_CClassDefNode(self, node):
1024         node = self.visit_ClassDefNode(node)
1025         if node.scope and node.scope.implemented:
1026             stats = []
1027             for entry in node.scope.var_entries:
1028                 if entry.needs_property:
1029                     property = self.create_Property(entry)
1030                     property.analyse_declarations(node.scope)
1031                     self.visit(property)
1032                     stats.append(property)
1033             if stats:
1034                 node.body.stats += stats
1035         return node
1036
1037     def visit_FuncDefNode(self, node):
1038         self.seen_vars_stack.append(cython.set())
1039         lenv = node.local_scope
1040         node.body.analyse_control_flow(lenv) # this will be totally refactored
1041         node.declare_arguments(lenv)
1042         for var, type_node in node.directive_locals.items():
1043             if not lenv.lookup_here(var):   # don't redeclare args
1044                 type = type_node.analyse_as_type(lenv)
1045                 if type:
1046                     lenv.declare_var(var, type, type_node.pos)
1047                 else:
1048                     error(type_node.pos, "Not a type")
1049         node.body.analyse_declarations(lenv)
1050         self.env_stack.append(lenv)
1051         self.visitchildren(node)
1052         self.env_stack.pop()
1053         self.seen_vars_stack.pop()
1054         return node
1055
1056     def visit_ScopedExprNode(self, node):
1057         env = self.env_stack[-1]
1058         node.analyse_declarations(env)
1059         # the node may or may not have a local scope
1060         if node.has_local_scope:
1061             self.seen_vars_stack.append(cython.set(self.seen_vars_stack[-1]))
1062             self.env_stack.append(node.expr_scope)
1063             node.analyse_scoped_declarations(node.expr_scope)
1064             self.visitchildren(node)
1065             self.env_stack.pop()
1066             self.seen_vars_stack.pop()
1067         else:
1068             node.analyse_scoped_declarations(env)
1069             self.visitchildren(node)
1070         return node
1071
1072     def visit_TempResultFromStatNode(self, node):
1073         self.visitchildren(node)
1074         node.analyse_declarations(self.env_stack[-1])
1075         return node
1076
1077     def visit_CStructOrUnionDefNode(self, node):
1078         # Create a wrapper node if needed.
1079         # We want to use the struct type information (so it can't happen
1080         # before this phase) but also create new objects to be declared
1081         # (so it can't happen later).
1082         # Note that we don't return the original node, as it is
1083         # never used after this phase.
1084         if True: # private (default)
1085             return None
1086
1087         self_value = ExprNodes.AttributeNode(
1088             pos = node.pos,
1089             obj = ExprNodes.NameNode(pos=node.pos, name=u"self"),
1090             attribute = EncodedString(u"value"))
1091         var_entries = node.entry.type.scope.var_entries
1092         attributes = []
1093         for entry in var_entries:
1094             attributes.append(ExprNodes.AttributeNode(pos = entry.pos,
1095                                                       obj = self_value,
1096                                                       attribute = entry.name))
1097         # __init__ assignments
1098         init_assignments = []
1099         for entry, attr in zip(var_entries, attributes):
1100             # TODO: branch on visibility
1101             init_assignments.append(self.init_assignment.substitute({
1102                     u"VALUE": ExprNodes.NameNode(entry.pos, name = entry.name),
1103                     u"ATTR": attr,
1104                 }, pos = entry.pos))
1105
1106         # create the class
1107         str_format = u"%s(%s)" % (node.entry.type.name, ("%s, " * len(attributes))[:-2])
1108         wrapper_class = self.struct_or_union_wrapper.substitute({
1109             u"INIT_ASSIGNMENTS": Nodes.StatListNode(node.pos, stats = init_assignments),
1110             u"IS_UNION": ExprNodes.BoolNode(node.pos, value = not node.entry.type.is_struct),
1111             u"MEMBER_TUPLE": ExprNodes.TupleNode(node.pos, args=attributes),
1112             u"STR_FORMAT": ExprNodes.StringNode(node.pos, value = EncodedString(str_format)),
1113             u"REPR_FORMAT": ExprNodes.StringNode(node.pos, value = EncodedString(str_format.replace("%s", "%r"))),
1114         }, pos = node.pos).stats[0]
1115         wrapper_class.class_name = node.name
1116         wrapper_class.shadow = True
1117         class_body = wrapper_class.body.stats
1118
1119         # fix value type
1120         assert isinstance(class_body[0].base_type, Nodes.CSimpleBaseTypeNode)
1121         class_body[0].base_type.name = node.name
1122
1123         # fix __init__ arguments
1124         init_method = class_body[1]
1125         assert isinstance(init_method, Nodes.DefNode) and init_method.name == '__init__'
1126         arg_template = init_method.args[1]
1127         if not node.entry.type.is_struct:
1128             arg_template.kw_only = True
1129         del init_method.args[1]
1130         for entry, attr in zip(var_entries, attributes):
1131             arg = copy.deepcopy(arg_template)
1132             arg.declarator.name = entry.name
1133             init_method.args.append(arg)
1134
1135         # setters/getters
1136         for entry, attr in zip(var_entries, attributes):
1137             # TODO: branch on visibility
1138             if entry.type.is_pyobject:
1139                 template = self.basic_pyobject_property
1140             else:
1141                 template = self.basic_property
1142             property = template.substitute({
1143                     u"ATTR": attr,
1144                 }, pos = entry.pos).stats[0]
1145             property.name = entry.name
1146             wrapper_class.body.stats.append(property)
1147
1148         wrapper_class.analyse_declarations(self.env_stack[-1])
1149         return self.visit_CClassDefNode(wrapper_class)
1150
1151     # Some nodes are no longer needed after declaration
1152     # analysis and can be dropped. The analysis was performed
1153     # on these nodes in a seperate recursive process from the
1154     # enclosing function or module, so we can simply drop them.
1155     def visit_CDeclaratorNode(self, node):
1156         # necessary to ensure that all CNameDeclaratorNodes are visited.
1157         self.visitchildren(node)
1158         return node
1159
1160     def visit_CTypeDefNode(self, node):
1161         return node
1162
1163     def visit_CBaseTypeNode(self, node):
1164         return None
1165
1166     def visit_CEnumDefNode(self, node):
1167         if node.visibility == 'public':
1168             return node
1169         else:
1170             return None
1171
1172     def visit_CNameDeclaratorNode(self, node):
1173         if node.name in self.seen_vars_stack[-1]:
1174             entry = self.env_stack[-1].lookup(node.name)
1175             if (entry is None or entry.visibility != 'extern'
1176                 and not entry.scope.is_c_class_scope):
1177                 warning(node.pos, "cdef variable '%s' declared after it is used" % node.name, 2)
1178         self.visitchildren(node)
1179         return node
1180
1181     def visit_CVarDefNode(self, node):
1182         # to ensure all CNameDeclaratorNodes are visited.
1183         self.visitchildren(node)
1184         return None
1185
1186     def create_Property(self, entry):
1187         if entry.visibility == 'public':
1188             if entry.type.is_pyobject:
1189                 template = self.basic_pyobject_property
1190             else:
1191                 template = self.basic_property
1192         elif entry.visibility == 'readonly':
1193             template = self.basic_property_ro
1194         property = template.substitute({
1195                 u"ATTR": ExprNodes.AttributeNode(pos=entry.pos,
1196                                                  obj=ExprNodes.NameNode(pos=entry.pos, name="self"),
1197                                                  attribute=entry.name),
1198             }, pos=entry.pos).stats[0]
1199         property.name = entry.name
1200         # ---------------------------------------
1201         # XXX This should go to AutoDocTransforms
1202         # ---------------------------------------
1203         if (Options.docstrings and
1204             self.current_directives['embedsignature']):
1205             attr_name = entry.name
1206             type_name = entry.type.declaration_code("", for_display=1)
1207             default_value = ''
1208             if not entry.type.is_pyobject:
1209                 type_name = "'%s'" % type_name
1210             elif entry.type.is_extension_type:
1211                 type_name = entry.type.module_name + '.' + type_name
1212             if entry.init is not None:
1213                 default_value = ' = ' + entry.init
1214             elif entry.init_to_none:
1215                 default_value = ' = ' + repr(None)
1216             docstring = attr_name + ': ' + type_name + default_value
1217             property.doc = EncodedString(docstring)
1218         # ---------------------------------------
1219         return property
1220
1221 class AnalyseExpressionsTransform(CythonTransform):
1222
1223     def visit_ModuleNode(self, node):
1224         node.scope.infer_types()
1225         node.body.analyse_expressions(node.scope)
1226         self.visitchildren(node)
1227         return node
1228
1229     def visit_FuncDefNode(self, node):
1230         node.local_scope.infer_types()
1231         node.body.analyse_expressions(node.local_scope)
1232         self.visitchildren(node)
1233         return node
1234
1235     def visit_ScopedExprNode(self, node):
1236         if node.has_local_scope:
1237             node.expr_scope.infer_types()
1238             node.analyse_scoped_expressions(node.expr_scope)
1239         self.visitchildren(node)
1240         return node
1241
1242 class ExpandInplaceOperators(EnvTransform):
1243
1244     def visit_InPlaceAssignmentNode(self, node):
1245         lhs = node.lhs
1246         rhs = node.rhs
1247         if lhs.type.is_cpp_class:
1248             # No getting around this exact operator here.
1249             return node
1250         if isinstance(lhs, ExprNodes.IndexNode) and lhs.is_buffer_access:
1251             # There is code to handle this case.
1252             return node
1253
1254         env = self.current_env()
1255         def side_effect_free_reference(node, setting=False):
1256             if isinstance(node, ExprNodes.NameNode):
1257                 return node, []
1258             elif node.type.is_pyobject and not setting:
1259                 node = LetRefNode(node)
1260                 return node, [node]
1261             elif isinstance(node, ExprNodes.IndexNode):
1262                 if node.is_buffer_access:
1263                     raise ValueError, "Buffer access"
1264                 base, temps = side_effect_free_reference(node.base)
1265                 index = LetRefNode(node.index)
1266                 return ExprNodes.IndexNode(node.pos, base=base, index=index), temps + [index]
1267             elif isinstance(node, ExprNodes.AttributeNode):
1268                 obj, temps = side_effect_free_reference(node.obj)
1269                 return ExprNodes.AttributeNode(node.pos, obj=obj, attribute=node.attribute), temps
1270             else:
1271                 node = LetRefNode(node)
1272                 return node, [node]
1273         try:
1274             lhs, let_ref_nodes = side_effect_free_reference(lhs, setting=True)
1275         except ValueError:
1276             return node
1277         dup = lhs.__class__(**lhs.__dict__)
1278         binop = ExprNodes.binop_node(node.pos,
1279                                      operator = node.operator,
1280                                      operand1 = dup,
1281                                      operand2 = rhs,
1282                                      inplace=True)
1283         # Manually analyse types for new node.
1284         lhs.analyse_target_types(env)
1285         dup.analyse_types(env)
1286         binop.analyse_operation(env)
1287         node = Nodes.SingleAssignmentNode(
1288             node.pos,
1289             lhs = lhs,
1290             rhs=binop.coerce_to(lhs.type, env))
1291         # Use LetRefNode to avoid side effects.
1292         let_ref_nodes.reverse()
1293         for t in let_ref_nodes:
1294             node = LetNode(t, node)
1295         return node
1296
1297     def visit_ExprNode(self, node):
1298         # In-place assignments can't happen within an expression.
1299         return node
1300
1301
1302 class AlignFunctionDefinitions(CythonTransform):
1303     """
1304     This class takes the signatures from a .pxd file and applies them to
1305     the def methods in a .py file.
1306     """
1307
1308     def visit_ModuleNode(self, node):
1309         self.scope = node.scope
1310         self.directives = node.directives
1311         self.visitchildren(node)
1312         return node
1313
1314     def visit_PyClassDefNode(self, node):
1315         pxd_def = self.scope.lookup(node.name)
1316         if pxd_def:
1317             if pxd_def.is_cclass:
1318                 return self.visit_CClassDefNode(node.as_cclass(), pxd_def)
1319             else:
1320                 error(node.pos, "'%s' redeclared" % node.name)
1321                 if pxd_def.pos:
1322                     error(pxd_def.pos, "previous declaration here")
1323                 return None
1324         else:
1325             return node
1326
1327     def visit_CClassDefNode(self, node, pxd_def=None):
1328         if pxd_def is None:
1329             pxd_def = self.scope.lookup(node.class_name)
1330         if pxd_def:
1331             outer_scope = self.scope
1332             self.scope = pxd_def.type.scope
1333         self.visitchildren(node)
1334         if pxd_def:
1335             self.scope = outer_scope
1336         return node
1337
1338     def visit_DefNode(self, node):
1339         pxd_def = self.scope.lookup(node.name)
1340         if pxd_def and (not pxd_def.scope or not pxd_def.scope.is_builtin_scope):
1341             if not pxd_def.is_cfunction:
1342                 error(node.pos, "'%s' redeclared" % node.name)
1343                 if pxd_def.pos:
1344                     error(pxd_def.pos, "previous declaration here")
1345                 return None
1346             node = node.as_cfunction(pxd_def)
1347         elif (self.scope.is_module_scope and self.directives['auto_cpdef']
1348               and node.is_cdef_func_compatible()):
1349             node = node.as_cfunction(scope=self.scope)
1350         # Enable this when nested cdef functions are allowed.
1351         # self.visitchildren(node)
1352         return node
1353
1354
1355 class YieldNodeCollector(TreeVisitor):
1356
1357     def __init__(self):
1358         super(YieldNodeCollector, self).__init__()
1359         self.yields = []
1360         self.returns = []
1361         self.has_return_value = False
1362
1363     def visit_Node(self, node):
1364         return self.visitchildren(node)
1365
1366     def visit_YieldExprNode(self, node):
1367         if self.has_return_value:
1368             error(node.pos, "'yield' outside function")
1369         self.yields.append(node)
1370         self.visitchildren(node)
1371
1372     def visit_ReturnStatNode(self, node):
1373         if node.value:
1374             self.has_return_value = True
1375             if self.yields:
1376                 error(node.pos, "'return' with argument inside generator")
1377         self.returns.append(node)
1378
1379     def visit_ClassDefNode(self, node):
1380         pass
1381
1382     def visit_FuncDefNode(self, node):
1383         pass
1384
1385     def visit_LambdaNode(self, node):
1386         pass
1387
1388     def visit_GeneratorExpressionNode(self, node):
1389         pass
1390
1391 class MarkClosureVisitor(CythonTransform):
1392
1393     def visit_ModuleNode(self, node):
1394         self.needs_closure = False
1395         self.visitchildren(node)
1396         return node
1397
1398     def visit_FuncDefNode(self, node):
1399         self.needs_closure = False
1400         self.visitchildren(node)
1401         node.needs_closure = self.needs_closure
1402         self.needs_closure = True
1403
1404         collector = YieldNodeCollector()
1405         collector.visitchildren(node)
1406
1407         if collector.yields:
1408             for i, yield_expr in enumerate(collector.yields):
1409                 yield_expr.label_num = i + 1
1410
1411             gbody = Nodes.GeneratorBodyDefNode(pos=node.pos,
1412                                                name=node.name,
1413                                                body=node.body)
1414             generator = Nodes.GeneratorDefNode(pos=node.pos,
1415                                                name=node.name,
1416                                                args=node.args,
1417                                                star_arg=node.star_arg,
1418                                                starstar_arg=node.starstar_arg,
1419                                                doc=node.doc,
1420                                                decorators=node.decorators,
1421                                                gbody=gbody,
1422                                                lambda_name=node.lambda_name)
1423             return generator
1424         return node
1425
1426     def visit_CFuncDefNode(self, node):
1427         self.visit_FuncDefNode(node)
1428         if node.needs_closure:
1429             error(node.pos, "closures inside cdef functions not yet supported")
1430         return node
1431
1432     def visit_LambdaNode(self, node):
1433         self.needs_closure = False
1434         self.visitchildren(node)
1435         node.needs_closure = self.needs_closure
1436         self.needs_closure = True
1437         return node
1438
1439     def visit_ClassDefNode(self, node):
1440         self.visitchildren(node)
1441         self.needs_closure = True
1442         return node
1443
1444 class CreateClosureClasses(CythonTransform):
1445     # Output closure classes in module scope for all functions
1446     # that really need it.
1447
1448     def __init__(self, context):
1449         super(CreateClosureClasses, self).__init__(context)
1450         self.path = []
1451         self.in_lambda = False
1452         self.generator_class = None
1453
1454     def visit_ModuleNode(self, node):
1455         self.module_scope = node.scope
1456         self.visitchildren(node)
1457         return node
1458
1459     def create_generator_class(self, target_module_scope, pos):
1460         if self.generator_class:
1461             return self.generator_class
1462         # XXX: make generator class creation cleaner
1463         entry = target_module_scope.declare_c_class(name='__pyx_Generator',
1464                     objstruct_cname='__pyx_Generator_object',
1465                     typeobj_cname='__pyx_Generator_type',
1466                     pos=pos, defining=True, implementing=True)
1467         klass = entry.type.scope
1468         klass.is_internal = True
1469         klass.directives = {'final': True}
1470
1471         body_type = PyrexTypes.create_typedef_type('generator_body',
1472                                                    PyrexTypes.c_void_ptr_type,
1473                                                    '__pyx_generator_body_t')
1474         klass.declare_var(pos=pos, name='body', cname='body',
1475                           type=body_type, is_cdef=True)
1476         klass.declare_var(pos=pos, name='is_running', cname='is_running', type=PyrexTypes.c_int_type,
1477                           is_cdef=True)
1478         klass.declare_var(pos=pos, name='resume_label', cname='resume_label', type=PyrexTypes.c_int_type,
1479                           is_cdef=True)
1480         klass.declare_var(pos=pos, name='exc_type', cname='exc_type',
1481                           type=PyrexTypes.py_object_type, is_cdef=True)
1482         klass.declare_var(pos=pos, name='exc_value', cname='exc_value',
1483                           type=PyrexTypes.py_object_type, is_cdef=True)
1484         klass.declare_var(pos=pos, name='exc_traceback', cname='exc_traceback',
1485                           type=PyrexTypes.py_object_type, is_cdef=True)
1486
1487         import TypeSlots
1488         e = klass.declare_pyfunction('send', pos)
1489         e.func_cname = '__Pyx_Generator_Send'
1490         e.signature = TypeSlots.binaryfunc
1491
1492         e = klass.declare_pyfunction('close', pos)
1493         e.func_cname = '__Pyx_Generator_Close'
1494         e.signature = TypeSlots.unaryfunc
1495
1496         e = klass.declare_pyfunction('throw', pos)
1497         e.func_cname = '__Pyx_Generator_Throw'
1498         e.signature = TypeSlots.pyfunction_signature
1499
1500         e = klass.declare_var('__iter__', PyrexTypes.py_object_type, pos, visibility='public')
1501         e.func_cname = 'PyObject_SelfIter'
1502
1503         e = klass.declare_var('__next__', PyrexTypes.py_object_type, pos, visibility='public')
1504         e.func_cname = '__Pyx_Generator_Next'
1505
1506         self.generator_class = entry.type
1507         return self.generator_class
1508
1509     def find_entries_used_in_closures(self, node):
1510         from_closure = []
1511         in_closure = []
1512         for name, entry in node.local_scope.entries.items():
1513             if entry.from_closure:
1514                 from_closure.append((name, entry))
1515             elif entry.in_closure:
1516                 in_closure.append((name, entry))
1517         return from_closure, in_closure
1518
1519     def create_class_from_scope(self, node, target_module_scope, inner_node=None):
1520         # skip generator body
1521         if node.is_generator_body:
1522             return
1523         # move local variables into closure
1524         if node.is_generator:
1525             for entry in node.local_scope.entries.values():
1526                 if not entry.from_closure:
1527                     entry.in_closure = True
1528
1529         from_closure, in_closure = self.find_entries_used_in_closures(node)
1530         in_closure.sort()
1531
1532         # Now from the begining
1533         node.needs_closure = False
1534         node.needs_outer_scope = False
1535
1536         func_scope = node.local_scope
1537         cscope = node.entry.scope
1538         while cscope.is_py_class_scope or cscope.is_c_class_scope:
1539             cscope = cscope.outer_scope
1540
1541         if not from_closure and (self.path or inner_node):
1542             if not inner_node:
1543                 if not node.assmt:
1544                     raise InternalError, "DefNode does not have assignment node"
1545                 inner_node = node.assmt.rhs
1546             inner_node.needs_self_code = False
1547             node.needs_outer_scope = False
1548
1549         base_type = None
1550         if node.is_generator:
1551             base_type = self.create_generator_class(target_module_scope, node.pos)
1552         elif not in_closure and not from_closure:
1553             return
1554         elif not in_closure:
1555             func_scope.is_passthrough = True
1556             func_scope.scope_class = cscope.scope_class
1557             node.needs_outer_scope = True
1558             return
1559
1560         as_name = '%s_%s' % (target_module_scope.next_id(Naming.closure_class_prefix), node.entry.cname)
1561
1562         entry = target_module_scope.declare_c_class(
1563             name=as_name, pos=node.pos, defining=True,
1564             implementing=True, base_type=base_type)
1565
1566         func_scope.scope_class = entry
1567         class_scope = entry.type.scope
1568         class_scope.is_internal = True
1569         class_scope.directives = {'final': True}
1570
1571         if from_closure:
1572             assert cscope.is_closure_scope
1573             class_scope.declare_var(pos=node.pos,
1574                                     name=Naming.outer_scope_cname,
1575                                     cname=Naming.outer_scope_cname,
1576                                     type=cscope.scope_class.type,
1577                                     is_cdef=True)
1578             node.needs_outer_scope = True
1579         for name, entry in in_closure:
1580             closure_entry = class_scope.declare_var(pos=entry.pos,
1581                                     name=entry.name,
1582                                     cname=entry.cname,
1583                                     type=entry.type,
1584                                     is_cdef=True)
1585             if entry.is_declared_generic:
1586                 closure_entry.is_declared_generic = 1
1587         node.needs_closure = True
1588         # Do it here because other classes are already checked
1589         target_module_scope.check_c_class(func_scope.scope_class)
1590
1591     def visit_LambdaNode(self, node):
1592         was_in_lambda = self.in_lambda
1593         self.in_lambda = True
1594         self.create_class_from_scope(node.def_node, self.module_scope, node)
1595         self.visitchildren(node)
1596         self.in_lambda = was_in_lambda
1597         return node
1598
1599     def visit_FuncDefNode(self, node):
1600         if self.in_lambda:
1601             self.visitchildren(node)
1602             return node
1603         if node.needs_closure or self.path:
1604             self.create_class_from_scope(node, self.module_scope)
1605             self.path.append(node)
1606             self.visitchildren(node)
1607             self.path.pop()
1608         return node
1609
1610
1611 class GilCheck(VisitorTransform):
1612     """
1613     Call `node.gil_check(env)` on each node to make sure we hold the
1614     GIL when we need it.  Raise an error when on Python operations
1615     inside a `nogil` environment.
1616     """
1617     def __call__(self, root):
1618         self.env_stack = [root.scope]
1619         self.nogil = False
1620         return super(GilCheck, self).__call__(root)
1621
1622     def visit_FuncDefNode(self, node):
1623         self.env_stack.append(node.local_scope)
1624         was_nogil = self.nogil
1625         self.nogil = node.local_scope.nogil
1626         if self.nogil and node.nogil_check:
1627             node.nogil_check(node.local_scope)
1628         self.visitchildren(node)
1629         self.env_stack.pop()
1630         self.nogil = was_nogil
1631         return node
1632
1633     def visit_GILStatNode(self, node):
1634         env = self.env_stack[-1]
1635         if self.nogil and node.nogil_check: node.nogil_check()
1636         was_nogil = self.nogil
1637         self.nogil = (node.state == 'nogil')
1638         self.visitchildren(node)
1639         self.nogil = was_nogil
1640         return node
1641
1642     def visit_Node(self, node):
1643         if self.env_stack and self.nogil and node.nogil_check:
1644             node.nogil_check(self.env_stack[-1])
1645         self.visitchildren(node)
1646         return node
1647
1648
1649 class TransformBuiltinMethods(EnvTransform):
1650
1651     def visit_SingleAssignmentNode(self, node):
1652         if node.declaration_only:
1653             return None
1654         else:
1655             self.visitchildren(node)
1656             return node
1657
1658     def visit_AttributeNode(self, node):
1659         self.visitchildren(node)
1660         return self.visit_cython_attribute(node)
1661
1662     def visit_NameNode(self, node):
1663         return self.visit_cython_attribute(node)
1664
1665     def visit_cython_attribute(self, node):
1666         attribute = node.as_cython_attribute()
1667         if attribute:
1668             if attribute == u'compiled':
1669                 node = ExprNodes.BoolNode(node.pos, value=True)
1670             elif attribute == u'NULL':
1671                 node = ExprNodes.NullNode(node.pos)
1672             elif attribute in (u'set', u'frozenset'):
1673                 node = ExprNodes.NameNode(node.pos, name=EncodedString(attribute),
1674                                           entry=self.current_env().builtin_scope().lookup_here(attribute))
1675             elif not PyrexTypes.parse_basic_type(attribute):
1676                 error(node.pos, u"'%s' not a valid cython attribute or is being used incorrectly" % attribute)
1677         return node
1678
1679     def _inject_locals(self, node, func_name):
1680         # locals()/dir() builtins
1681         lenv = self.current_env()
1682         entry = lenv.lookup_here(func_name)
1683         if entry:
1684             # not the builtin
1685             return node
1686         pos = node.pos
1687         if func_name == 'locals':
1688             if len(node.args) > 0:
1689                 error(self.pos, "Builtin 'locals()' called with wrong number of args, expected 0, got %d"
1690                       % len(node.args))
1691                 return node
1692             items = [ ExprNodes.DictItemNode(pos,
1693                                              key=ExprNodes.StringNode(pos, value=var),
1694                                              value=ExprNodes.NameNode(pos, name=var))
1695                       for var in lenv.entries ]
1696             return ExprNodes.DictNode(pos, key_value_pairs=items)
1697         else:
1698             if len(node.args) > 1:
1699                 error(self.pos, "Builtin 'dir()' called with wrong number of args, expected 0-1, got %d"
1700                       % len(node.args))
1701                 return node
1702             elif len(node.args) == 1:
1703                 # optimised in Builtin.py
1704                 return node
1705             items = [ ExprNodes.StringNode(pos, value=var) for var in lenv.entries ]
1706             return ExprNodes.ListNode(pos, args=items)
1707
1708     def visit_SimpleCallNode(self, node):
1709         if isinstance(node.function, ExprNodes.NameNode):
1710             func_name = node.function.name
1711             if func_name in ('dir', 'locals'):
1712                 return self._inject_locals(node, func_name)
1713
1714         # cython.foo
1715         function = node.function.as_cython_attribute()
1716         if function:
1717             if function in InterpretCompilerDirectives.unop_method_nodes:
1718                 if len(node.args) != 1:
1719                     error(node.function.pos, u"%s() takes exactly one argument" % function)
1720                 else:
1721                     node = InterpretCompilerDirectives.unop_method_nodes[function](node.function.pos, operand=node.args[0])
1722             elif function in InterpretCompilerDirectives.binop_method_nodes:
1723                 if len(node.args) != 2:
1724                     error(node.function.pos, u"%s() takes exactly two arguments" % function)
1725                 else:
1726                     node = InterpretCompilerDirectives.binop_method_nodes[function](node.function.pos, operand1=node.args[0], operand2=node.args[1])
1727             elif function == u'cast':
1728                 if len(node.args) != 2:
1729                     error(node.function.pos, u"cast() takes exactly two arguments")
1730                 else:
1731                     type = node.args[0].analyse_as_type(self.current_env())
1732                     if type:
1733                         node = ExprNodes.TypecastNode(node.function.pos, type=type, operand=node.args[1])
1734                     else:
1735                         error(node.args[0].pos, "Not a type")
1736             elif function == u'sizeof':
1737                 if len(node.args) != 1:
1738                     error(node.function.pos, u"sizeof() takes exactly one argument")
1739                 else:
1740                     type = node.args[0].analyse_as_type(self.current_env())
1741                     if type:
1742                         node = ExprNodes.SizeofTypeNode(node.function.pos, arg_type=type)
1743                     else:
1744                         node = ExprNodes.SizeofVarNode(node.function.pos, operand=node.args[0])
1745             elif function == 'cmod':
1746                 if len(node.args) != 2:
1747                     error(node.function.pos, u"cmod() takes exactly two arguments")
1748                 else:
1749                     node = ExprNodes.binop_node(node.function.pos, '%', node.args[0], node.args[1])
1750                     node.cdivision = True
1751             elif function == 'cdiv':
1752                 if len(node.args) != 2:
1753                     error(node.function.pos, u"cdiv() takes exactly two arguments")
1754                 else:
1755                     node = ExprNodes.binop_node(node.function.pos, '/', node.args[0], node.args[1])
1756                     node.cdivision = True
1757             elif function == u'set':
1758                 node.function = ExprNodes.NameNode(node.pos, name=EncodedString('set'))
1759             else:
1760                 error(node.function.pos, u"'%s' not a valid cython language construct" % function)
1761
1762         self.visitchildren(node)
1763         return node
1764
1765
1766 class DebugTransform(CythonTransform):
1767     """
1768     Create debug information and all functions' visibility to extern in order
1769     to enable debugging.
1770     """
1771
1772     def __init__(self, context, options, result):
1773         super(DebugTransform, self).__init__(context)
1774         self.visited = cython.set()
1775         # our treebuilder and debug output writer
1776         # (see Cython.Debugger.debug_output.CythonDebugWriter)
1777         self.tb = self.context.gdb_debug_outputwriter
1778         #self.c_output_file = options.output_file
1779         self.c_output_file = result.c_file
1780
1781         # Closure support, basically treat nested functions as if the AST were
1782         # never nested
1783         self.nested_funcdefs = []
1784
1785         # tells visit_NameNode whether it should register step-into functions
1786         self.register_stepinto = False
1787
1788     def visit_ModuleNode(self, node):
1789         self.tb.module_name = node.full_module_name
1790         attrs = dict(
1791             module_name=node.full_module_name,
1792             filename=node.pos[0].filename,
1793             c_filename=self.c_output_file)
1794
1795         self.tb.start('Module', attrs)
1796
1797         # serialize functions
1798         self.tb.start('Functions')
1799         # First, serialize functions normally...
1800         self.visitchildren(node)
1801
1802         # ... then, serialize nested functions
1803         for nested_funcdef in self.nested_funcdefs:
1804             self.visit_FuncDefNode(nested_funcdef)
1805
1806         self.register_stepinto = True
1807         self.serialize_modulenode_as_function(node)
1808         self.register_stepinto = False
1809         self.tb.end('Functions')
1810
1811         # 2.3 compatibility. Serialize global variables
1812         self.tb.start('Globals')
1813         entries = {}
1814
1815         for k, v in node.scope.entries.iteritems():
1816             if (v.qualified_name not in self.visited and not
1817                 v.name.startswith('__pyx_') and not
1818                 v.type.is_cfunction and not
1819                 v.type.is_extension_type):
1820                 entries[k]= v
1821
1822         self.serialize_local_variables(entries)
1823         self.tb.end('Globals')
1824         # self.tb.end('Module') # end Module after the line number mapping in
1825         # Cython.Compiler.ModuleNode.ModuleNode._serialize_lineno_map
1826         return node
1827
1828     def visit_FuncDefNode(self, node):
1829         self.visited.add(node.local_scope.qualified_name)
1830
1831         if getattr(node, 'is_wrapper', False):
1832             return node
1833
1834         if self.register_stepinto:
1835             self.nested_funcdefs.append(node)
1836             return node
1837
1838         # node.entry.visibility = 'extern'
1839         if node.py_func is None:
1840             pf_cname = ''
1841         else:
1842             pf_cname = node.py_func.entry.func_cname
1843
1844         attrs = dict(
1845             name=node.entry.name,
1846             cname=node.entry.func_cname,
1847             pf_cname=pf_cname,
1848             qualified_name=node.local_scope.qualified_name,
1849             lineno=str(node.pos[1]))
1850
1851         self.tb.start('Function', attrs=attrs)
1852
1853         self.tb.start('Locals')
1854         self.serialize_local_variables(node.local_scope.entries)
1855         self.tb.end('Locals')
1856
1857         self.tb.start('Arguments')
1858         for arg in node.local_scope.arg_entries:
1859             self.tb.start(arg.name)
1860             self.tb.end(arg.name)
1861         self.tb.end('Arguments')
1862
1863         self.tb.start('StepIntoFunctions')
1864         self.register_stepinto = True
1865         self.visitchildren(node)
1866         self.register_stepinto = False
1867         self.tb.end('StepIntoFunctions')
1868         self.tb.end('Function')
1869
1870         return node
1871
1872     def visit_NameNode(self, node):
1873         if (self.register_stepinto and
1874             node.type.is_cfunction and
1875             getattr(node, 'is_called', False) and
1876             node.entry.func_cname is not None):
1877             # don't check node.entry.in_cinclude, as 'cdef extern: ...'
1878             # declared functions are not 'in_cinclude'.
1879             # This means we will list called 'cdef' functions as
1880             # "step into functions", but this is not an issue as they will be
1881             # recognized as Cython functions anyway.
1882             attrs = dict(name=node.entry.func_cname)
1883             self.tb.start('StepIntoFunction', attrs=attrs)
1884             self.tb.end('StepIntoFunction')
1885
1886         self.visitchildren(node)
1887         return node
1888
1889     def serialize_modulenode_as_function(self, node):
1890         """
1891         Serialize the module-level code as a function so the debugger will know
1892         it's a "relevant frame" and it will know where to set the breakpoint
1893         for 'break modulename'.
1894         """
1895         name = node.full_module_name.rpartition('.')[-1]
1896
1897         cname_py2 = 'init' + name
1898         cname_py3 = 'PyInit_' + name
1899
1900         py2_attrs = dict(
1901             name=name,
1902             cname=cname_py2,
1903             pf_cname='',
1904             # Ignore the qualified_name, breakpoints should be set using
1905             # `cy break modulename:lineno` for module-level breakpoints.
1906             qualified_name='',
1907             lineno='1',
1908             is_initmodule_function="True",
1909         )
1910
1911         py3_attrs = dict(py2_attrs, cname=cname_py3)
1912
1913         self._serialize_modulenode_as_function(node, py2_attrs)
1914         self._serialize_modulenode_as_function(node, py3_attrs)
1915
1916     def _serialize_modulenode_as_function(self, node, attrs):
1917         self.tb.start('Function', attrs=attrs)
1918
1919         self.tb.start('Locals')
1920         self.serialize_local_variables(node.scope.entries)
1921         self.tb.end('Locals')
1922
1923         self.tb.start('Arguments')
1924         self.tb.end('Arguments')
1925
1926         self.tb.start('StepIntoFunctions')
1927         self.register_stepinto = True
1928         self.visitchildren(node)
1929         self.register_stepinto = False
1930         self.tb.end('StepIntoFunctions')
1931
1932         self.tb.end('Function')
1933
1934     def serialize_local_variables(self, entries):
1935         for entry in entries.values():
1936             if entry.type.is_pyobject:
1937                 vartype = 'PythonObject'
1938             else:
1939                 vartype = 'CObject'
1940
1941             if entry.from_closure:
1942                 # We're dealing with a closure where a variable from an outer
1943                 # scope is accessed, get it from the scope object.
1944                 cname = '%s->%s' % (Naming.cur_scope_cname,
1945                                     entry.outer_entry.cname)
1946
1947                 qname = '%s.%s.%s' % (entry.scope.outer_scope.qualified_name,
1948                                       entry.scope.name,
1949                                       entry.name)
1950             elif entry.in_closure:
1951                 cname = '%s->%s' % (Naming.cur_scope_cname,
1952                                     entry.cname)
1953                 qname = entry.qualified_name
1954             else:
1955                 cname = entry.cname
1956                 qname = entry.qualified_name
1957
1958             if not entry.pos:
1959                 # this happens for variables that are not in the user's code,
1960                 # e.g. for the global __builtins__, __doc__, etc. We can just
1961                 # set the lineno to 0 for those.
1962                 lineno = '0'
1963             else:
1964                 lineno = str(entry.pos[1])
1965
1966             attrs = dict(
1967                 name=entry.name,
1968                 cname=cname,
1969                 qualified_name=qname,
1970                 type=vartype,
1971                 lineno=lineno)
1972
1973             self.tb.start('LocalVar', attrs)
1974             self.tb.end('LocalVar')
1975