| 1 | """
|
| 2 | control_flow_pass.py - AST pass that builds a control flow graph.
|
| 3 | """
|
| 4 | import collections
|
| 5 |
|
| 6 | import mypy
|
| 7 | from mypy.nodes import (Block, Expression, Statement, CallExpr, FuncDef,
|
| 8 | IfStmt, NameExpr, MemberExpr, IndexExpr, TupleExpr,
|
| 9 | IntExpr)
|
| 10 |
|
| 11 | from mypy.types import CallableType, Instance, Type, UnionType, NoneTyp, TupleType
|
| 12 |
|
| 13 | from mycpp.crash import catch_errors
|
| 14 | from mycpp.util import SymbolToString, SplitPyName
|
| 15 | from mycpp import visitor
|
| 16 | from mycpp import util
|
| 17 | from mycpp.util import SymbolPath
|
| 18 | from mycpp import pass_state
|
| 19 |
|
| 20 | from typing import Dict, List, Union, Optional, overload, TYPE_CHECKING
|
| 21 |
|
| 22 | if TYPE_CHECKING:
|
| 23 | from mycpp import conversion_pass
|
| 24 | from mycpp import cppgen_pass
|
| 25 |
|
| 26 |
|
| 27 | def GetObjectTypeName(t: Type) -> SymbolPath:
|
| 28 | if isinstance(t, Instance):
|
| 29 | return SplitPyName(t.type.fullname)
|
| 30 |
|
| 31 | elif isinstance(t, UnionType):
|
| 32 | assert len(t.items) == 2
|
| 33 | if isinstance(t.items[0], NoneTyp):
|
| 34 | return GetObjectTypeName(t.items[1])
|
| 35 |
|
| 36 | return GetObjectTypeName(t.items[0])
|
| 37 |
|
| 38 | assert False, t
|
| 39 |
|
| 40 |
|
| 41 | INVALID_ID = -99 # statement IDs are positive
|
| 42 |
|
| 43 |
|
| 44 | class Build(visitor.SimpleVisitor):
|
| 45 |
|
| 46 | def __init__(self, types: Dict[Expression,
|
| 47 | Type], virtual: pass_state.Virtual,
|
| 48 | local_vars: 'cppgen_pass.AllLocalVars',
|
| 49 | dot_exprs: 'conversion_pass.DotExprs') -> None:
|
| 50 | visitor.SimpleVisitor.__init__(self)
|
| 51 |
|
| 52 | self.types = types
|
| 53 | self.cflow_graphs: Dict[
|
| 54 | SymbolPath, pass_state.ControlFlowGraph] = collections.defaultdict(
|
| 55 | pass_state.ControlFlowGraph)
|
| 56 | self.current_statement_id = INVALID_ID
|
| 57 | self.current_func_node: Optional[FuncDef] = None
|
| 58 | self.loop_stack: List[pass_state.CfgLoopContext] = []
|
| 59 | self.virtual = virtual
|
| 60 | self.local_vars = local_vars
|
| 61 | self.dot_exprs = dot_exprs
|
| 62 | self.heap_counter = 0
|
| 63 | # statement object -> SymbolPath of the callee
|
| 64 | self.callees: Dict['mypy.nodes.CallExpr', SymbolPath] = {}
|
| 65 | self.current_lval: Optional[Expression] = None
|
| 66 |
|
| 67 | self.inside_switch = False
|
| 68 | self.inside_loop = False
|
| 69 |
|
| 70 | def current_cfg(self) -> pass_state.ControlFlowGraph:
|
| 71 | if not self.current_func_node:
|
| 72 | return None
|
| 73 |
|
| 74 | return self.cflow_graphs[SplitPyName(self.current_func_node.fullname)]
|
| 75 |
|
| 76 | def resolve_callee(
|
| 77 | self, o: CallExpr, current_class_name: Optional[util.SymbolPath]
|
| 78 | ) -> Optional[util.SymbolPath]:
|
| 79 | """
|
| 80 | Returns the fully qualified name of the callee in the given call
|
| 81 | expression.
|
| 82 |
|
| 83 | Member functions are prefixed by the names of the classes that contain
|
| 84 | them. For example, the name of the callee in the last statement of the
|
| 85 | snippet below is `module.SomeObject.Foo`.
|
| 86 |
|
| 87 | x = module.SomeObject()
|
| 88 | x.Foo()
|
| 89 |
|
| 90 | Free-functions defined in the local module are referred to by their
|
| 91 | normal fully qualified names. The function `foo` in a module called
|
| 92 | `moduleA` would is named `moduleA.foo`. Calls to free-functions defined
|
| 93 | in imported modules are named the same way.
|
| 94 | """
|
| 95 |
|
| 96 | if isinstance(o.callee, NameExpr):
|
| 97 | return SplitPyName(o.callee.fullname)
|
| 98 |
|
| 99 | elif isinstance(o.callee, MemberExpr):
|
| 100 | if isinstance(o.callee.expr, NameExpr):
|
| 101 | is_module = isinstance(self.dot_exprs.get(o.callee),
|
| 102 | pass_state.ModuleMember)
|
| 103 | if is_module:
|
| 104 | return (SplitPyName(o.callee.expr.fullname) +
|
| 105 | (o.callee.name, ))
|
| 106 |
|
| 107 | elif o.callee.expr.name == 'self':
|
| 108 | assert current_class_name
|
| 109 | return current_class_name + (o.callee.name, )
|
| 110 |
|
| 111 | else:
|
| 112 | local_type = None
|
| 113 | for name, t in self.local_vars.get(self.current_func_node,
|
| 114 | []):
|
| 115 | if name == o.callee.expr.name:
|
| 116 | local_type = t
|
| 117 | break
|
| 118 |
|
| 119 | if local_type:
|
| 120 | if isinstance(local_type, str):
|
| 121 | return (SplitPyName(local_type) +
|
| 122 | (o.callee.name, ))
|
| 123 |
|
| 124 | elif isinstance(local_type, Instance):
|
| 125 | return (SplitPyName(local_type.type.fullname) +
|
| 126 | (o.callee.name, ))
|
| 127 |
|
| 128 | elif isinstance(local_type, UnionType):
|
| 129 | assert len(local_type.items) == 2
|
| 130 | return (SplitPyName(
|
| 131 | local_type.items[0].type.fullname) +
|
| 132 | (o.callee.expr.name, ))
|
| 133 |
|
| 134 | else:
|
| 135 | assert not isinstance(local_type, CallableType)
|
| 136 | # primitive type or string. don't care.
|
| 137 | return None
|
| 138 |
|
| 139 | else:
|
| 140 | # context or exception handler. probably safe to ignore.
|
| 141 | return None
|
| 142 |
|
| 143 | else:
|
| 144 | t = self.types.get(o.callee.expr)
|
| 145 | if isinstance(t, Instance):
|
| 146 | return SplitPyName(t.type.fullname) + (o.callee.name, )
|
| 147 |
|
| 148 | elif isinstance(t, UnionType):
|
| 149 | assert len(t.items) == 2
|
| 150 | return (SplitPyName(t.items[0].type.fullname) +
|
| 151 | (o.callee.name, ))
|
| 152 |
|
| 153 | elif o.callee.expr and getattr(o.callee.expr, 'fullname',
|
| 154 | None):
|
| 155 | return (SplitPyName(o.callee.expr.fullname) +
|
| 156 | (o.callee.name, ))
|
| 157 |
|
| 158 | else:
|
| 159 | # constructors of things that we don't care about.
|
| 160 | return None
|
| 161 |
|
| 162 | # Don't currently get here
|
| 163 | raise AssertionError()
|
| 164 |
|
| 165 | def get_ref_name(self, expr: Expression) -> Optional[util.SymbolPath]:
|
| 166 | """
|
| 167 | To do dataflow analysis we need to track changes to objects, which
|
| 168 | requires naming them. This function returns the name of the object
|
| 169 | referred to by the given expression. If the expression doesn't refer to
|
| 170 | an object or variable it returns None.
|
| 171 |
|
| 172 | Objects are named slightly differently than they appear in the source
|
| 173 | code.
|
| 174 |
|
| 175 | Objects referenced by local variables are referred to by the name of the
|
| 176 | local. For example, the name of the object in both statements below is
|
| 177 | `x`.
|
| 178 |
|
| 179 | x = module.SomeObject()
|
| 180 | x = None
|
| 181 |
|
| 182 | Member expressions are named after the parent object's type. For
|
| 183 | example, the names of the objects in the member assignment statements
|
| 184 | below are both `module.SomeObject.member_a`. This makes it possible to
|
| 185 | track data flow across object members without having to track individual
|
| 186 | heap objects, which would increase the search space for analyses and
|
| 187 | slow things down.
|
| 188 |
|
| 189 | x = module.SomeObject()
|
| 190 | y = module.SomeObject()
|
| 191 | x.member_a = 'foo'
|
| 192 | y.member_a = 'bar'
|
| 193 |
|
| 194 | Index expressions are named after their bases, for the same reasons as
|
| 195 | member expressions. The coarse-grained precision should lead to an
|
| 196 | over-approximation of where objects are in use, but should not miss any
|
| 197 | references. This should be fine for our purposes. In the snippet below
|
| 198 | the last two assignments are named `x` and `module.SomeObject.a_list`.
|
| 199 |
|
| 200 | x = [None] # list[Thing]
|
| 201 | y = module.SomeObject()
|
| 202 | x[0] = Thing()
|
| 203 | y.a_list[1] = Blah()
|
| 204 |
|
| 205 | Index expressions over tuples are treated differently, though. Tuples
|
| 206 | have a fixed size, tend to be small, and their elements have distinct
|
| 207 | types. So, each element can be (and probably needs to be) individually
|
| 208 | named. In the snippet below, the name of the RHS in the second
|
| 209 | assignment is `t.0`.
|
| 210 |
|
| 211 | t = (1, 2, 3, 4)
|
| 212 | x = t[0]
|
| 213 |
|
| 214 | The examples above all deal with assignments, but these rules apply to
|
| 215 | any expression that uses an object or variable.
|
| 216 | """
|
| 217 | if isinstance(expr,
|
| 218 | NameExpr) and expr.name not in {'True', 'False', 'None'}:
|
| 219 | return (expr.name, )
|
| 220 |
|
| 221 | elif isinstance(expr, MemberExpr):
|
| 222 | dot_expr = self.dot_exprs[expr]
|
| 223 | if isinstance(dot_expr, pass_state.ModuleMember):
|
| 224 | return dot_expr.module_path + (dot_expr.member, )
|
| 225 |
|
| 226 | elif isinstance(dot_expr, pass_state.HeapObjectMember):
|
| 227 | obj_name = self.get_ref_name(dot_expr.object_expr)
|
| 228 | if obj_name:
|
| 229 | # XXX: add a new case like pass_state.ExpressionMember for
|
| 230 | # cases when the LHS of . isn't a reference (e.g.
|
| 231 | # builtin/assign_osh.py:54)
|
| 232 | return obj_name + (dot_expr.member, )
|
| 233 |
|
| 234 | elif isinstance(dot_expr, pass_state.StackObjectMember):
|
| 235 | return (self.get_ref_name(dot_expr.object_expr) +
|
| 236 | (dot_expr.member, ))
|
| 237 |
|
| 238 | elif isinstance(expr, IndexExpr):
|
| 239 | if isinstance(self.types[expr.base], TupleType):
|
| 240 | assert isinstance(expr.index, IntExpr)
|
| 241 | return self.get_ref_name(expr.base) + (str(expr.index.value), )
|
| 242 |
|
| 243 | return self.get_ref_name(expr.base)
|
| 244 |
|
| 245 | return None
|
| 246 |
|
| 247 | #
|
| 248 | # COPIED from IRBuilder
|
| 249 | #
|
| 250 |
|
| 251 | @overload
|
| 252 | def accept(self, node: Expression) -> None:
|
| 253 | ...
|
| 254 |
|
| 255 | @overload
|
| 256 | def accept(self, node: Statement) -> None:
|
| 257 | ...
|
| 258 |
|
| 259 | def accept(self, node: Union[Statement, Expression]) -> None:
|
| 260 | with catch_errors(self.module_path, node.line):
|
| 261 | if isinstance(node, Expression):
|
| 262 | node.accept(self)
|
| 263 | else:
|
| 264 | cfg = self.current_cfg()
|
| 265 | # Most statements have empty visitors because they don't
|
| 266 | # require any special logic. Create statements for them
|
| 267 | # here. Don't create statements from blocks to avoid
|
| 268 | # stuttering.
|
| 269 | if cfg and not isinstance(node, Block):
|
| 270 | self.current_statement_id = cfg.AddStatement()
|
| 271 |
|
| 272 | node.accept(self)
|
| 273 |
|
| 274 | # Statements
|
| 275 |
|
| 276 | def visit_for_stmt(self, o: 'mypy.nodes.ForStmt') -> None:
|
| 277 | cfg = self.current_cfg()
|
| 278 | was_inside_loop = self.inside_loop
|
| 279 | self.inside_loop = True
|
| 280 | with pass_state.CfgLoopContext(
|
| 281 | cfg, entry=self.current_statement_id) as loop:
|
| 282 | self.accept(o.expr)
|
| 283 | self.loop_stack.append(loop)
|
| 284 | self.accept(o.body)
|
| 285 | self.loop_stack.pop()
|
| 286 |
|
| 287 | # Let the outer loop toggle this off
|
| 288 | if not was_inside_loop:
|
| 289 | self.inside_loop = False
|
| 290 |
|
| 291 | def _handle_switch(self, expr: Expression, o: 'mypy.nodes.WithStmt',
|
| 292 | cfg: pass_state.ControlFlowGraph) -> None:
|
| 293 | assert len(o.body.body) == 1, o.body.body
|
| 294 | if_node = o.body.body[0]
|
| 295 | assert isinstance(if_node, IfStmt), if_node
|
| 296 | cases: util.CaseList = []
|
| 297 | default_block = util.CollectSwitchCases(self.module_path, if_node,
|
| 298 | cases)
|
| 299 | with pass_state.CfgBranchContext(
|
| 300 | cfg, self.current_statement_id) as branch_ctx:
|
| 301 | for expr, body in cases:
|
| 302 | self.accept(expr)
|
| 303 | assert expr is not None, expr
|
| 304 | with branch_ctx.AddBranch():
|
| 305 | self.accept(body)
|
| 306 |
|
| 307 | if not isinstance(default_block, int):
|
| 308 | with branch_ctx.AddBranch():
|
| 309 | self.accept(default_block)
|
| 310 |
|
| 311 | def oils_visit_switch(self, expr: 'mypy.nodes.CallExpr',
|
| 312 | o: 'mypy.nodes.WithStmt',
|
| 313 | switch_type: str) -> None:
|
| 314 | """Build control flow graph for switch statements."""
|
| 315 | cfg = self.current_cfg()
|
| 316 | was_inside_loop = self.inside_loop
|
| 317 | self.inside_switch = True
|
| 318 | self.inside_loop = False
|
| 319 | self._handle_switch(expr, o, cfg)
|
| 320 | self.inside_switch = False
|
| 321 | # Restore if we were inside a loop
|
| 322 | if was_inside_loop:
|
| 323 | self.inside_loop = True
|
| 324 |
|
| 325 | def visit_with_stmt(self, o: 'mypy.nodes.WithStmt') -> None:
|
| 326 | cfg = self.current_cfg()
|
| 327 |
|
| 328 | assert len(o.expr) == 1, o.expr
|
| 329 | expr = o.expr[0]
|
| 330 |
|
| 331 | assert isinstance(expr, CallExpr), expr
|
| 332 | self.accept(expr)
|
| 333 |
|
| 334 | # Note: we have 'with alloc.ctx_SourceCode'
|
| 335 | #assert isinstance(expr.callee, NameExpr), expr.callee
|
| 336 | if isinstance(expr.callee, NameExpr):
|
| 337 | callee_name = expr.callee.name
|
| 338 | if callee_name in ('switch', 'str_switch', 'tagswitch'):
|
| 339 | self.oils_visit_switch(expr, o, callee_name)
|
| 340 | return
|
| 341 |
|
| 342 | with pass_state.CfgBlockContext(cfg, self.current_statement_id):
|
| 343 | self.accept(o.body)
|
| 344 |
|
| 345 | def oils_visit_func_def(self, o: 'mypy.nodes.FuncDef',
|
| 346 | current_class_name: Optional[util.SymbolPath],
|
| 347 | current_method_name: Optional[str]) -> None:
|
| 348 | # For virtual methods, pretend that the method on the base class calls
|
| 349 | # the same method on every subclass. This way call sites using the
|
| 350 | # abstract base class will over-approximate the set of call paths they
|
| 351 | # can take when checking if they can reach MaybeCollect().
|
| 352 | if current_class_name and self.virtual.IsVirtual(
|
| 353 | current_class_name, o.name):
|
| 354 | key = (current_class_name, o.name)
|
| 355 | base = self.virtual.virtuals[key]
|
| 356 | if base:
|
| 357 | sub = SymbolToString(current_class_name + (o.name, ),
|
| 358 | delim='.')
|
| 359 | base_key = base[0] + (base[1], )
|
| 360 | cfg = self.cflow_graphs[base_key]
|
| 361 | cfg.AddFact(0, pass_state.FunctionCall(sub))
|
| 362 |
|
| 363 | self.current_func_node = o
|
| 364 | cfg = self.current_cfg()
|
| 365 | for arg in o.arguments:
|
| 366 | cfg.AddFact(0,
|
| 367 | pass_state.Definition((arg.variable.name, ), '$Empty'))
|
| 368 |
|
| 369 | self.accept(o.body)
|
| 370 | self.current_func_node = None
|
| 371 | self.current_statement_id = INVALID_ID
|
| 372 |
|
| 373 | def visit_while_stmt(self, o: 'mypy.nodes.WhileStmt') -> None:
|
| 374 | cfg = self.current_cfg()
|
| 375 | was_inside_loop = self.inside_loop
|
| 376 | self.inside_loop = True
|
| 377 | with pass_state.CfgLoopContext(
|
| 378 | cfg, entry=self.current_statement_id) as loop:
|
| 379 | self.accept(o.expr)
|
| 380 | self.loop_stack.append(loop)
|
| 381 | self.accept(o.body)
|
| 382 | self.loop_stack.pop()
|
| 383 |
|
| 384 | # Let the outer loop toggle this off
|
| 385 | if not was_inside_loop:
|
| 386 | self.inside_loop = False
|
| 387 |
|
| 388 | def visit_return_stmt(self, o: 'mypy.nodes.ReturnStmt') -> None:
|
| 389 | cfg = self.current_cfg()
|
| 390 | if cfg:
|
| 391 | cfg.AddDeadend(self.current_statement_id)
|
| 392 |
|
| 393 | if o.expr:
|
| 394 | self.accept(o.expr)
|
| 395 |
|
| 396 | def visit_if_stmt(self, o: 'mypy.nodes.IfStmt') -> None:
|
| 397 | cfg = self.current_cfg()
|
| 398 |
|
| 399 | if util.ShouldVisitIfExpr(o):
|
| 400 | for expr in o.expr:
|
| 401 | self.accept(expr)
|
| 402 |
|
| 403 | with pass_state.CfgBranchContext(
|
| 404 | cfg, self.current_statement_id) as branch_ctx:
|
| 405 | if util.ShouldVisitIfBody(o):
|
| 406 | with branch_ctx.AddBranch():
|
| 407 | for node in o.body:
|
| 408 | self.accept(node)
|
| 409 |
|
| 410 | if util.ShouldVisitElseBody(o):
|
| 411 | with branch_ctx.AddBranch():
|
| 412 | self.accept(o.else_body)
|
| 413 |
|
| 414 | def visit_break_stmt(self, o: 'mypy.nodes.BreakStmt') -> None:
|
| 415 | if self.inside_switch and not self.inside_loop:
|
| 416 | # since it will break out of the loop in Python, but only leave
|
| 417 | # the switch case in C++, # disallow break inside a switch
|
| 418 | self.report_error(
|
| 419 | o, "'break' is not allowed to be used inside a switch")
|
| 420 | if len(self.loop_stack):
|
| 421 | self.loop_stack[-1].AddBreak(self.current_statement_id)
|
| 422 |
|
| 423 | def visit_continue_stmt(self, o: 'mypy.nodes.ContinueStmt') -> None:
|
| 424 | if len(self.loop_stack):
|
| 425 | self.loop_stack[-1].AddContinue(self.current_statement_id)
|
| 426 |
|
| 427 | def visit_raise_stmt(self, o: 'mypy.nodes.RaiseStmt') -> None:
|
| 428 | cfg = self.current_cfg()
|
| 429 | if cfg:
|
| 430 | cfg.AddDeadend(self.current_statement_id)
|
| 431 |
|
| 432 | if o.expr:
|
| 433 | self.accept(o.expr)
|
| 434 |
|
| 435 | def visit_try_stmt(self, o: 'mypy.nodes.TryStmt') -> None:
|
| 436 | cfg = self.current_cfg()
|
| 437 | with pass_state.CfgBranchContext(cfg,
|
| 438 | self.current_statement_id) as try_ctx:
|
| 439 | with try_ctx.AddBranch() as try_block:
|
| 440 | self.accept(o.body)
|
| 441 |
|
| 442 | for t, v, handler in zip(o.types, o.vars, o.handlers):
|
| 443 | with try_ctx.AddBranch(try_block.exit):
|
| 444 | self.accept(handler)
|
| 445 |
|
| 446 | # 2024-12(andy): SimpleVisitor now has a special case for:
|
| 447 | #
|
| 448 | # myvar = [x for x in other]
|
| 449 | #
|
| 450 | # This seems like it should affect the control flow graph, since we are no
|
| 451 | # longer calling oils_visit_assignment_stmt, and are instead calling
|
| 452 | # oils_visit_assign_to_listcomp.
|
| 453 | #
|
| 454 | # We may need more test coverage?
|
| 455 | # List comprehensions are arguably a weird/legacy part of the mycpp IR that
|
| 456 | # should be cleaned up.
|
| 457 | #
|
| 458 | # We do NOT allow:
|
| 459 | #
|
| 460 | # myfunc([x for x in other])
|
| 461 | #
|
| 462 | # See mycpp/visitor.py and mycpp/cppgen_pass.py for how this is used.
|
| 463 |
|
| 464 | #def oils_visit_assign_to_listcomp(self, o: 'mypy.nodes.AssignmentStmt', lval: NameExpr) -> None:
|
| 465 |
|
| 466 | def oils_visit_assignment_stmt(self, o: 'mypy.nodes.AssignmentStmt',
|
| 467 | lval: Expression, rval: Expression,
|
| 468 | current_method_name: Optional[str],
|
| 469 | at_global_scope: bool) -> None:
|
| 470 | cfg = self.current_cfg()
|
| 471 | if cfg:
|
| 472 | lval_names = []
|
| 473 | if isinstance(lval, TupleExpr):
|
| 474 | lval_names.extend(
|
| 475 | [self.get_ref_name(item) for item in lval.items])
|
| 476 |
|
| 477 | else:
|
| 478 | lval_names.append(self.get_ref_name(lval))
|
| 479 |
|
| 480 | assert len(lval_names), lval
|
| 481 |
|
| 482 | rval_type = self.types[rval]
|
| 483 | rval_names: List[Optional[util.SymbolPath]] = []
|
| 484 | if isinstance(rval, CallExpr):
|
| 485 | # The RHS is either an object constructor or something that
|
| 486 | # returns a primitive type (e.g. Tuple[int, int] or str).
|
| 487 | # XXX: When we add inter-procedural analysis we should treat
|
| 488 | # these not as definitions but as some new kind of assignment.
|
| 489 | rval_names = [None for _ in lval_names]
|
| 490 |
|
| 491 | elif isinstance(rval, TupleExpr) and len(lval_names) == 1:
|
| 492 | # We're constructing a tuple. Since tuples have have a fixed
|
| 493 | # (and usually small) size, we can name each of the
|
| 494 | # elements.
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| 495 | base = lval_names[0]
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| 496 | lval_names = [
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| 497 | base + (str(i), ) for i in range(len(rval.items))
|
| 498 | ]
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| 499 | rval_names = [self.get_ref_name(item) for item in rval.items]
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| 500 |
|
| 501 | elif isinstance(rval_type, TupleType):
|
| 502 | # We're unpacking a tuple. Like the tuple construction case,
|
| 503 | # give each element a name.
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| 504 | rval_name = self.get_ref_name(rval)
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| 505 | assert rval_name, rval
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| 506 | rval_names = [
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| 507 | rval_name + (str(i), ) for i in range(len(lval_names))
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| 508 | ]
|
| 509 |
|
| 510 | else:
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| 511 | rval_names = [self.get_ref_name(rval)]
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| 512 |
|
| 513 | assert len(rval_names) == len(lval_names)
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| 514 |
|
| 515 | for lhs, rhs in zip(lval_names, rval_names):
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| 516 | assert lhs, lval
|
| 517 | if rhs:
|
| 518 | # In this case rhe RHS is another variable. Record the
|
| 519 | # assignment so we can keep track of aliases.
|
| 520 | cfg.AddFact(self.current_statement_id,
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| 521 | pass_state.Assignment(lhs, rhs))
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| 522 | else:
|
| 523 | # In this case the RHS is either some kind of literal (e.g.
|
| 524 | # [] or 'foo') or a call to an object constructor. Mark this
|
| 525 | # statement as an (re-)definition of a variable.
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| 526 | cfg.AddFact(
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| 527 | self.current_statement_id,
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| 528 | pass_state.Definition(
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| 529 | lhs, '$HeapObject(h{})'.format(self.heap_counter)),
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| 530 | )
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| 531 | self.heap_counter += 1
|
| 532 |
|
| 533 | # TODO: Could simplify this
|
| 534 | self.current_lval = lval
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| 535 | self.accept(lval)
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| 536 | self.current_lval = None
|
| 537 |
|
| 538 | self.accept(rval)
|
| 539 |
|
| 540 | # Expressions
|
| 541 |
|
| 542 | def oils_visit_member_expr(self, o: 'mypy.nodes.MemberExpr') -> None:
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| 543 | self.accept(o.expr)
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| 544 | cfg = self.current_cfg()
|
| 545 | if (cfg and
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| 546 | not isinstance(self.dot_exprs[o], pass_state.ModuleMember) and
|
| 547 | o != self.current_lval):
|
| 548 | ref = self.get_ref_name(o)
|
| 549 | if ref:
|
| 550 | cfg.AddFact(self.current_statement_id, pass_state.Use(ref))
|
| 551 |
|
| 552 | def oils_visit_name_expr(self, o: 'mypy.nodes.NameExpr') -> None:
|
| 553 | cfg = self.current_cfg()
|
| 554 | if cfg and o != self.current_lval:
|
| 555 | is_local = False
|
| 556 | for name, t in self.local_vars.get(self.current_func_node, []):
|
| 557 | if name == o.name:
|
| 558 | is_local = True
|
| 559 | break
|
| 560 |
|
| 561 | ref = self.get_ref_name(o)
|
| 562 | if ref and is_local:
|
| 563 | cfg.AddFact(self.current_statement_id, pass_state.Use(ref))
|
| 564 |
|
| 565 | def oils_visit_call_expr(
|
| 566 | self, o: 'mypy.nodes.CallExpr',
|
| 567 | current_class_name: Optional[util.SymbolPath]) -> None:
|
| 568 | cfg = self.current_cfg()
|
| 569 | if self.current_func_node:
|
| 570 | full_callee = self.resolve_callee(o, current_class_name)
|
| 571 | if full_callee:
|
| 572 | self.callees[o] = full_callee
|
| 573 | cfg.AddFact(
|
| 574 | self.current_statement_id,
|
| 575 | pass_state.FunctionCall(
|
| 576 | SymbolToString(full_callee, delim='.')))
|
| 577 |
|
| 578 | for i, arg in enumerate(o.args):
|
| 579 | arg_ref = self.get_ref_name(arg)
|
| 580 | if arg_ref:
|
| 581 | cfg.AddFact(self.current_statement_id,
|
| 582 | pass_state.Bind(arg_ref, full_callee, i))
|
| 583 |
|
| 584 | self.accept(o.callee)
|
| 585 | for arg in o.args:
|
| 586 | self.accept(arg)
|