# Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. import copy from paddle.utils import gast from collections import defaultdict from paddle.fluid import unique_name from paddle.fluid.dygraph.dygraph_to_static.static_analysis import ( AstNodeWrapper, ) from paddle.fluid.dygraph.dygraph_to_static.static_analysis import NodeVarType from paddle.fluid.dygraph.dygraph_to_static.static_analysis import ( StaticAnalysisVisitor, ) from paddle.fluid.dygraph.dygraph_to_static.utils import ast_to_source_code from paddle.fluid.dygraph.dygraph_to_static.utils import get_attribute_full_name from paddle.fluid.dygraph.dygraph_to_static.utils import ( create_nonlocal_stmt_nodes, create_get_args_node, create_set_args_node, ) from paddle.fluid.dygraph.dygraph_to_static.utils import ( FunctionNameLivenessAnalysis, ) from .ifelse_transformer import ARGS_NAME from paddle.fluid.dygraph.dygraph_to_static.base_transformer import ( BaseTransformer, ) from paddle.fluid.dygraph.dygraph_to_static.base_transformer import ( ForLoopTuplePreTransformer, ) from paddle.fluid.dygraph.dygraph_to_static.base_transformer import ( ForNodeVisitor, ) from paddle.fluid.dygraph.dygraph_to_static.utils import ( GetterSetterHelper, create_name_str, ) __all__ = ['LoopTransformer', 'NameVisitor'] WHILE_CONDITION_PREFIX = 'while_condition' WHILE_BODY_PREFIX = 'while_body' FOR_CONDITION_PREFIX = 'for_loop_condition' FOR_BODY_PREFIX = 'for_loop_body' def create_while_nodes( condition_name, body_name, loop_var_names, push_pop_names, getter_name, setter_name, ): """ Returns a list of gast.Node which represents the calling of Paddle controlflow while_loop. Usually, the list just contain 1 statement such as: [a, b, c] = paddle.jit.dy2static.convert_while_loop( condition_name, body_name, [a, b, c]) where a, b, c are in loop_var_names. However, if loop_var_names contains property such as foo.x, we cannot assign the property as output of convert_while_loop because Python property is a kind of read-only attribute. To handle the case, we replace the attributes which are output of convert_while_loop with generated variables, then if we know the attribute is not read-only at runtime, we assign the attribute. The created statements are like: [a, b, __attribute_variable_1] = paddle.jit.dy2static.convert_while_loop( condition_name, body_name, [a, b, foo.x]) if not isinstance(getattr(type(foo), x, None), property): foo.x = __attribute_variable_1 The number of above statements is not only 1, that's why the return type is a list of gast.Node. """ # NOTE(liym27): # It's better to parse the source code into an AST node than to customize an AST node # including child nodes, because it is easy to mistake the ast node type when customizing the node. # # For example: loop_var_names = [a, b, foo.x], the type of `a` or `b` is gast.Name, # but the type of `foo.x` gast.Attribute. # We have to make loop_var_names and assign_loop_var_names with same order # set doesn't have order so we convert it to list loop_var_names = list(loop_var_names) assign_loop_var_names = [] for name in loop_var_names: assign_loop_var_names.append(name) while_func_name = "_jst.While" while_node_str = ( "{}({}, {}, {}, {}, return_name_ids={}, push_pop_names={})".format( while_func_name, condition_name, body_name, getter_name, setter_name, create_name_str(loop_var_names), create_name_str(push_pop_names), ) ) while_node = gast.parse(while_node_str).body[0] ret = [while_node] return ret class NameVisitor(gast.NodeVisitor): ''' Analysis name liveness for loop transformer ''' def __init__(self, root_node): # Set of gast.Name or gast.Attribute for variables self.current_seen_vars = set() # List of gast.While/gast.For nodes self.current_loop = [] # List of nodes that have scope of variables. self.nodes_with_scope = [] self.blacklist_names = {"False", "True", "None"} # Mapping from gast.While/gast.For to variable nodes self.before_loop_body_vars = defaultdict(set) # NOTE: Use ordered list as dict value self.in_loop_vars = defaultdict(list) # Mapping from gast.While/gast.For to variable nodes which is condition # of loop or being modified during the loop self.write_in_loop = defaultdict(set) self.condition_vars = defaultdict(set) self.in_condition = False # Some names are types, we shouldn't record them as loop var names. self.type_vars = set() self.static_analysis_visitor = StaticAnalysisVisitor(root_node) self.node_to_wrapper_map = ( self.static_analysis_visitor.get_node_to_wrapper_map() ) self.visit(root_node) def get_loop_var_names(self, node): assert isinstance( node, (gast.While, gast.For) ), "Input node is not gast loop node" loop_var_names = set() create_var_names = set() read_context = {type(gast.Load()), type(gast.AugLoad())} in_loop_vars_list = self.in_loop_vars[node] # get dict `var_name_to_ctxs` var_name_to_ctxs = defaultdict(list) for var_node in in_loop_vars_list: var_name_to_ctxs[self._var_node_to_name(var_node)].append( var_node.ctx ) in_loop_vars = set(in_loop_vars_list) in_loop_vars = self._remove_unnecessary_vars(in_loop_vars, node) in_loop_name_strs = self._var_nodes_to_names(in_loop_vars) before_loop_body_vars = self.before_loop_body_vars[node] before_loop_body_vars = self._remove_unnecessary_vars( before_loop_body_vars, node ) before_loop_name_strs = self._var_nodes_to_names(before_loop_body_vars) after_loop_vars = ( self.current_seen_vars - before_loop_body_vars - in_loop_vars ) after_loop_vars = self._remove_unnecessary_vars(after_loop_vars, node) after_loop_name_strs = self._var_nodes_to_names( after_loop_vars, read_context ) condition_vars = self.condition_vars[node] condition_names = self._var_nodes_to_names(condition_vars) write_vars = self.write_in_loop[node] write_names = self._var_nodes_to_names(write_vars) name_to_type = {} for var in in_loop_vars: wrapper = self.node_to_wrapper_map[var] name_to_type[self._var_node_to_name(var)] = wrapper.node_var_type for name in in_loop_name_strs: if name in before_loop_name_strs: # If a variable is used in loop and created before loop # If this var is a basic variable and read-only and not # condition var, it may not be loop_var else it should # be in loop_var as input if (name not in condition_names) and (name not in write_names): continue loop_var_names.add(name) elif name in after_loop_name_strs: # If a variable is created in the while loop and read after # loop, it should be in loop_var and we should create it # because name in after_loop_name must be initialized in loop # So it is write-only, we don't have to filter read-only basic # vars out loop_var_names.add(name) create_var_names.add(name) else: # If a variable is used and created in loop, but used before created, # it should be in loop_var and we should create it. # For example, `var_a` should be in loop_var and we should create it. # # res = 0 # for i, x in enumerate(x_array): # if i > 2: # x = func1(var_a) # var_a = func2(x) # is_created = False for ctx in var_name_to_ctxs[name]: if isinstance(ctx, gast.Store): is_created = True if ( isinstance(var_name_to_ctxs[name][0], gast.Load) and is_created ): loop_var_names.add(name) create_var_names.add(name) return loop_var_names, create_var_names def visit_Name(self, node): if self._is_call_func_name_node(node): self.generic_visit(node) return if node.id in self.blacklist_names: self.generic_visit(node) return self.current_seen_vars.add(node) write_context = { type(gast.Store()), type(gast.AugStore()), type(gast.Del()), } for loop_node in self.current_loop: self.in_loop_vars[loop_node].append(node) if type(node.ctx) in write_context: self.write_in_loop[loop_node].add(node) if self.in_condition: self.condition_vars[loop_node].add(node) self.generic_visit(node) def visit_FunctionDef(self, node): self.nodes_with_scope.append(node) self.blacklist_names.add(node.name) # The variables in the function are not visible to the outside scope. before_func_seen_vars = copy.copy(self.current_seen_vars) self.generic_visit(node) self.nodes_with_scope.pop() # After exiting the scope of the node, variables in this scope # should be removed from self.current_seen_vars. if self.nodes_with_scope: self.current_seen_vars = before_func_seen_vars def visit(self, node): method = 'visit_' + node.__class__.__name__ visitor = getattr(self, method, self.generic_visit) ret = visitor(node) return ret def visit_Attribute(self, node): if self._is_call_func_name_node(node): return attr_full_name = get_attribute_full_name(node) # Class variables are not allowed to appear in the arguments list # of defined function under class methods in Python. """ def class_func(self): def while_loop_body(self.x, y) # `self.x` is illegal. """ # TODO: If do change the variable with `self.var`, need a better # way to deal with this case. if attr_full_name.startswith("self."): return self.current_seen_vars.add(node) for loop_node in self.current_loop: self.in_loop_vars[loop_node].append(node) # sub-nodes are visited during get_attribute_full_name and we shouldn't # visit again def visit_For(self, node): self.current_loop.append(node) self.in_condition = True self.visit(node.target) self.visit(node.iter) self.in_condition = False self.before_loop_body_vars[node] = copy.copy(self.current_seen_vars) self.generic_visit(node) self.current_loop.pop() def visit_While(self, node): self.current_loop.append(node) self.in_condition = True self.visit(node.test) self.in_condition = False self.before_loop_body_vars[node] = copy.copy(self.current_seen_vars) self.generic_visit(node) self.current_loop.pop() def visit_Call(self, node): # Store type var names such as "isinstance(x, some_type_names)" and # Remove them later if isinstance(node.func, gast.Name) and node.func.id == 'isinstance': type_node = node.args[1] if isinstance(type_node, gast.Tuple): for element in type_node.elts: self.type_vars.add(ast_to_source_code(element).strip()) else: self.type_vars.add(ast_to_source_code(type_node).strip()) self.generic_visit(node) def _var_nodes_to_names(self, node_set, ctx_filter_set=None): ret = set() for node in node_set: if ctx_filter_set is None or type(node.ctx) in ctx_filter_set: ret.add(self._var_node_to_name(node)) return ret def _var_node_to_name(self, node): if isinstance(node, gast.Name): return node.id elif isinstance(node, gast.Attribute): return get_attribute_full_name(node) def _node_var_type_is_basic(self, node_var_type): basic_types = { NodeVarType.BOOLEAN, NodeVarType.INT, NodeVarType.FLOAT, NodeVarType.STRING, } for t in node_var_type: if t in basic_types: return True return False def _is_call_func_name_node(self, node): parent_node = self._get_parent_node(node) if isinstance(parent_node, gast.Call) and parent_node.func == node: return True return False def _is_global_or_nonlocal(self, node): return False def _is_ancestor_node(self, ancestor_node, node): parent_node = self._get_parent_node(node) while parent_node is not None: if parent_node == ancestor_node: return True parent_node = self._get_parent_node(parent_node) return False def _get_parent_node(self, node): wrapper_node = self.node_to_wrapper_map.get(node) if wrapper_node: if wrapper_node.parent: parent_node = wrapper_node.parent.node return parent_node return None def _remove_unnecessary_vars(self, loop_vars, loop_node): """ Remove unnecessary vars from before_loop_vars, after_loop_vars or in_loop_vars about loop_node. 1. Remove target vars of gast.For from before_loop_vars or after_loop_vars. 2. Remove vars only in gast.comprehension. 3. Remove vars that are type names, for example: "isinstance(x, var_type_name)" :param loop_vars: before_loop_vars, after_loop_vars or in_loop_vars of loop_node. :param loop_node: Current loop node. """ def filter_name_nodes_from(root_node, target_var_names): """ Filter children with gast.Name type from node.(inclusivly) """ name_nodes = set() if isinstance(root_node, gast.Name): if node.id in target_var_names: name_nodes.add(root_node) for child_node in gast.walk(root_node): if isinstance(child_node, gast.Name): if child_node.id in target_var_names: name_nodes.add(child_node) return name_nodes vars_of_list_generator = set() target_vars_of_for_node = set() for name_node in loop_vars: if not isinstance(name_node, gast.Name): continue parent_node = self._get_parent_node(name_node) # NOTE: gast.For.target or gast.comprehension.target can be gast.Tuple. # For examples: # 1) `for i, j in enumerate(x)` has two target vars: i and j # 2) `[x for x,y in array]` has two target vars: x and y if isinstance(parent_node, gast.Tuple): parent_node = self._get_parent_node(parent_node) # 1. Get vars only in gast.comprehension. # For examples: # 1) [x for x,y in array] -> x, x, y # 2) [f(x) for x in array] -> x # 3) [func(x, y) for x in array] -> x, x if isinstance(parent_node, gast.comprehension): # 1.1 target vars in list/set comprehensions target_node = parent_node.target if isinstance(target_node, gast.Tuple): target_vars = target_node.elts else: target_vars = [target_node] vars_of_list_generator = vars_of_list_generator | set( target_vars ) # 1.2 vars from target vars used in elt_node target_var_names = {var.id for var in target_vars} comp_node = self._get_parent_node(parent_node) elt_nodes = [] if isinstance(comp_node, gast.ListComp): elt_nodes.append(comp_node.elt) elif isinstance(comp_node, gast.DictComp): elt_nodes.extend([comp_node.key, comp_node.value]) for node in elt_nodes: vars_of_list_generator |= filter_name_nodes_from( node, target_var_names ) # 2. Get target vars or vars from target vars used in for-loop but the for-loop is # 1) not the "loop_node" itself # 2) not the ancestor of the "loop_node" # # For examples: # for k in range(x): # if it's this "loop_node", i or j both should be target vars. # # do something # # for i in range(a): # if it's this "loop_node", k or j should be in target vars but i should not. # for j in range(a): # if it's this "loop_node", k should be in target_vars but i or j should not. # x = i+j elif isinstance(parent_node, gast.For): if parent_node is loop_node: continue if self._is_ancestor_node(parent_node, loop_node): continue # 2.1 target vars in gast.For node. target_node = parent_node.target if isinstance(target_node, gast.Tuple): target_vars = target_node.elts else: target_vars = [target_node] target_vars_of_for_node = target_vars_of_for_node | set( target_vars ) # 2.2 vars from target vars used in for-loop target_vars_name_strs = {var.id for var in target_vars_of_for_node} for var in loop_vars: if not isinstance(var, gast.Name): continue if ( var.id in target_vars_name_strs and var not in self.condition_vars[loop_node] ): target_vars_of_for_node.add(var) removed_vars = target_vars_of_for_node | vars_of_list_generator # 3. Remove var type names which are stored in self.type_vars for var in loop_vars: if ast_to_source_code(var).strip() in self.type_vars: removed_vars.add(var) return loop_vars - removed_vars class LoopTransformer(BaseTransformer): """ This class transforms python while/for statement into Static Graph Ast """ def __init__(self, wrapper_root): assert isinstance( wrapper_root, AstNodeWrapper ), "Input non-AstNodeWrapper node for the initialization of LoopTransformer." self.wrapper_root = wrapper_root self.root = wrapper_root.node FunctionNameLivenessAnalysis(self.root) def transform(self): ForLoopTuplePreTransformer(self.wrapper_root).transform() self.visit(self.root) def visit_While(self, node): self.generic_visit(node) new_stmts = self.get_while_stmt_nodes(node) return new_stmts def visit_For(self, node): self.generic_visit(node) new_stmts = self.get_for_stmt_nodes(node) return new_stmts def replace_stmt_list(self, body_list): if not isinstance(body_list, list): return i = 0 while i < len(body_list): if isinstance(body_list[i], gast.While): new_stmts = self.get_while_stmt_nodes(body_list[i]) body_list[i : i + 1] = new_stmts i += len(new_stmts) elif isinstance(body_list[i], gast.For): new_stmts = self.get_for_stmt_nodes(body_list[i]) body_list[i : i + 1] = new_stmts i += len(new_stmts) else: i += 1 def get_for_stmt_nodes(self, node): # TODO: consider for - else in python # 1. get key statements for different cases # NOTE 1: three key statements: # 1). init_stmts: list[node], prepare nodes of for loop, may not only one # 2). cond_stmt: node, condition node to judge whether continue loop # 3). body_stmts: list[node], updated loop body, sometimes we should change # the original statement in body, not just append new statement # # NOTE 2: The following `for` statements will be transformed to `while` statements: # 1). for x in range(*) # 2). for x in iter_var # 3). for i, x in enumerate(*) current_for_node_parser = ForNodeVisitor(node) stmts_tuple = current_for_node_parser.parse() if stmts_tuple is None: return [node] init_stmts, cond_stmt, body_stmts = stmts_tuple # 2. get original loop vars loop_var_names, create_var_names = ( node.pd_scope.modified_vars(), node.pd_scope.created_vars(), ) push_pop_names = list(node.pd_scope.variadic_length_vars()) # TODO: Remove the bunch of code? We have the unique format `for A in B:` # NOTE: in 'for x in var' or 'for i, x in enumerate(var)' cases, # we need append new loop var & remove useless loop var # 1. for x in var -> x is no need # 2. for i, x in enumerate(var) -> x is no need if current_for_node_parser.is_for_iter(): iter_var_name = current_for_node_parser.iter_var_name iter_idx_name = current_for_node_parser.iter_idx_name loop_var_names.add(iter_idx_name) if current_for_node_parser.enum_idx_name is not None: loop_var_names.add(current_for_node_parser.enum_idx_name) # 3. prepare result statement list new_stmts = [] # Python can create variable in loop and use it out of loop, E.g. # # for x in range(10): # y += x # print(x) # x = 10 # # We don't need to create static variable for them, because # we do this in CreateUndefinedVarTransformer # create non-local statement for body and cond. nonlocal_names = list(loop_var_names | create_var_names) nonlocal_names.sort() # TODO(dev): Need a better way to deal this. if ARGS_NAME in nonlocal_names: nonlocal_names.remove(ARGS_NAME) nonlocal_stmt_node = create_nonlocal_stmt_nodes(nonlocal_names) # 4. append init statements new_stmts.extend(init_stmts) # 5. create & append condition function node condition_func_node = gast.FunctionDef( name=unique_name.generate(FOR_CONDITION_PREFIX), args=gast.arguments( args=[], posonlyargs=[], vararg=None, kwonlyargs=[], kw_defaults=None, kwarg=None, defaults=[], ), body=nonlocal_stmt_node + [gast.Return(value=cond_stmt)], decorator_list=[], returns=None, type_comment=None, ) new_stmts.append(condition_func_node) # 6. create & append loop body function node # append return values for loop body body_func_node = gast.FunctionDef( name=unique_name.generate(FOR_BODY_PREFIX), args=gast.arguments( args=[], posonlyargs=[], vararg=None, kwonlyargs=[], kw_defaults=None, kwarg=None, defaults=[], ), body=nonlocal_stmt_node + body_stmts, decorator_list=[], returns=None, type_comment=None, ) new_stmts.append(body_func_node) helper = GetterSetterHelper(None, None, nonlocal_names, push_pop_names) get_args_node = create_get_args_node(helper.union()) set_args_node = create_set_args_node(helper.union()) # 7. create & append while loop node while_loop_nodes = create_while_nodes( condition_func_node.name, body_func_node.name, nonlocal_names, push_pop_names, get_args_node.name, set_args_node.name, ) new_stmts.extend([get_args_node, set_args_node]) new_stmts.extend(while_loop_nodes) return new_stmts def get_while_stmt_nodes(self, node): loop_var_names, create_var_names = ( node.pd_scope.modified_vars(), node.pd_scope.created_vars(), ) push_pop_names = list(node.pd_scope.variadic_length_vars()) new_stmts = [] # create non-local statement for body and cond. nonlocal_names = list(loop_var_names | create_var_names) nonlocal_names.sort() # TODO(dev): Need a better way to deal this. if ARGS_NAME in nonlocal_names: nonlocal_names.remove(ARGS_NAME) nonlocal_stmt_node = create_nonlocal_stmt_nodes(nonlocal_names) # Python can create variable in loop and use it out of loop, E.g. # # while x < 10: # x += 1 # y = x # z = y # # We don't need to create static variable for those variables, because # we do this in CreateUndefinedVarTransformer condition_func_node = gast.FunctionDef( name=unique_name.generate(WHILE_CONDITION_PREFIX), args=gast.arguments( args=[], posonlyargs=[], vararg=None, kwonlyargs=[], kw_defaults=None, kwarg=None, defaults=[], ), body=nonlocal_stmt_node + [gast.Return(value=node.test)], decorator_list=[], returns=None, type_comment=None, ) new_stmts.append(condition_func_node) new_body = node.body body_func_node = gast.FunctionDef( name=unique_name.generate(WHILE_BODY_PREFIX), args=gast.arguments( args=[], posonlyargs=[], vararg=None, kwonlyargs=[], kw_defaults=None, kwarg=None, defaults=[], ), body=nonlocal_stmt_node + new_body, decorator_list=[], returns=None, type_comment=None, ) new_stmts.append(body_func_node) helper = GetterSetterHelper(None, None, nonlocal_names, push_pop_names) get_args_node = create_get_args_node(helper.union()) set_args_node = create_set_args_node(helper.union()) while_loop_nodes = create_while_nodes( condition_func_node.name, body_func_node.name, nonlocal_names, push_pop_names, get_args_node.name, set_args_node.name, ) new_stmts.extend([get_args_node, set_args_node]) new_stmts.extend(while_loop_nodes) return new_stmts