| # Licensed under the Apache License: http://www.apache.org/licenses/LICENSE-2.0 |
| # For details: https://github.com/nedbat/coveragepy/blob/master/NOTICE.txt |
| |
| """Code parsing for coverage.py.""" |
| |
| from __future__ import annotations |
| |
| import ast |
| import functools |
| import collections |
| import os |
| import re |
| import sys |
| import token |
| import tokenize |
| |
| from dataclasses import dataclass |
| from types import CodeType |
| from typing import ( |
| cast, Any, Callable, Dict, Iterable, List, Optional, Protocol, Sequence, |
| Set, Tuple, |
| ) |
| |
| from coverage import env |
| from coverage.bytecode import code_objects |
| from coverage.debug import short_stack |
| from coverage.exceptions import NoSource, NotPython |
| from coverage.misc import nice_pair |
| from coverage.phystokens import generate_tokens |
| from coverage.types import TArc, TLineNo |
| |
| |
| class PythonParser: |
| """Parse code to find executable lines, excluded lines, etc. |
| |
| This information is all based on static analysis: no code execution is |
| involved. |
| |
| """ |
| def __init__( |
| self, |
| text: str | None = None, |
| filename: str | None = None, |
| exclude: str | None = None, |
| ) -> None: |
| """ |
| Source can be provided as `text`, the text itself, or `filename`, from |
| which the text will be read. Excluded lines are those that match |
| `exclude`, a regex string. |
| |
| """ |
| assert text or filename, "PythonParser needs either text or filename" |
| self.filename = filename or "<code>" |
| if text is not None: |
| self.text: str = text |
| else: |
| from coverage.python import get_python_source |
| try: |
| self.text = get_python_source(self.filename) |
| except OSError as err: |
| raise NoSource(f"No source for code: '{self.filename}': {err}") from err |
| |
| self.exclude = exclude |
| |
| # The parsed AST of the text. |
| self._ast_root: ast.AST | None = None |
| |
| # The normalized line numbers of the statements in the code. Exclusions |
| # are taken into account, and statements are adjusted to their first |
| # lines. |
| self.statements: set[TLineNo] = set() |
| |
| # The normalized line numbers of the excluded lines in the code, |
| # adjusted to their first lines. |
| self.excluded: set[TLineNo] = set() |
| |
| # The raw_* attributes are only used in this class, and in |
| # lab/parser.py to show how this class is working. |
| |
| # The line numbers that start statements, as reported by the line |
| # number table in the bytecode. |
| self.raw_statements: set[TLineNo] = set() |
| |
| # The raw line numbers of excluded lines of code, as marked by pragmas. |
| self.raw_excluded: set[TLineNo] = set() |
| |
| # The line numbers of class definitions. |
| self.raw_classdefs: set[TLineNo] = set() |
| |
| # The line numbers of docstring lines. |
| self.raw_docstrings: set[TLineNo] = set() |
| |
| # Internal detail, used by lab/parser.py. |
| self.show_tokens = False |
| |
| # A dict mapping line numbers to lexical statement starts for |
| # multi-line statements. |
| self._multiline: dict[TLineNo, TLineNo] = {} |
| |
| # Lazily-created arc data, and missing arc descriptions. |
| self._all_arcs: set[TArc] | None = None |
| self._missing_arc_fragments: TArcFragments | None = None |
| |
| def lines_matching(self, regex: str) -> set[TLineNo]: |
| """Find the lines matching a regex. |
| |
| Returns a set of line numbers, the lines that contain a match for |
| `regex`. The entire line needn't match, just a part of it. |
| Handles multiline regex patterns. |
| |
| """ |
| regex_c = re.compile(regex, re.MULTILINE) |
| matches: set[TLineNo] = set() |
| |
| last_start = 0 |
| last_start_line = 0 |
| for match in regex_c.finditer(self.text): |
| start, end = match.span() |
| start_line = last_start_line + self.text.count('\n', last_start, start) |
| end_line = last_start_line + self.text.count('\n', last_start, end) |
| matches.update(self._multiline.get(i, i) for i in range(start_line + 1, end_line + 2)) |
| last_start = start |
| last_start_line = start_line |
| return matches |
| |
| def _raw_parse(self) -> None: |
| """Parse the source to find the interesting facts about its lines. |
| |
| A handful of attributes are updated. |
| |
| """ |
| # Find lines which match an exclusion pattern. |
| if self.exclude: |
| self.raw_excluded = self.lines_matching(self.exclude) |
| self.excluded = set(self.raw_excluded) |
| |
| # The current number of indents. |
| indent: int = 0 |
| # An exclusion comment will exclude an entire clause at this indent. |
| exclude_indent: int = 0 |
| # Are we currently excluding lines? |
| excluding: bool = False |
| # The line number of the first line in a multi-line statement. |
| first_line: int = 0 |
| # Is the file empty? |
| empty: bool = True |
| # Parenthesis (and bracket) nesting level. |
| nesting: int = 0 |
| |
| assert self.text is not None |
| tokgen = generate_tokens(self.text) |
| for toktype, ttext, (slineno, _), (elineno, _), ltext in tokgen: |
| if self.show_tokens: # pragma: debugging |
| print("%10s %5s %-20r %r" % ( |
| tokenize.tok_name.get(toktype, toktype), |
| nice_pair((slineno, elineno)), ttext, ltext, |
| )) |
| if toktype == token.INDENT: |
| indent += 1 |
| elif toktype == token.DEDENT: |
| indent -= 1 |
| elif toktype == token.OP: |
| if ttext == ":" and nesting == 0: |
| should_exclude = ( |
| self.excluded.intersection(range(first_line, elineno + 1)) |
| ) |
| if not excluding and should_exclude: |
| # Start excluding a suite. We trigger off of the colon |
| # token so that the #pragma comment will be recognized on |
| # the same line as the colon. |
| self.excluded.add(elineno) |
| exclude_indent = indent |
| excluding = True |
| elif ttext in "([{": |
| nesting += 1 |
| elif ttext in ")]}": |
| nesting -= 1 |
| elif toktype == token.NEWLINE: |
| if first_line and elineno != first_line: |
| # We're at the end of a line, and we've ended on a |
| # different line than the first line of the statement, |
| # so record a multi-line range. |
| for l in range(first_line, elineno+1): |
| self._multiline[l] = first_line |
| first_line = 0 |
| |
| if ttext.strip() and toktype != tokenize.COMMENT: |
| # A non-white-space token. |
| empty = False |
| if not first_line: |
| # The token is not white space, and is the first in a statement. |
| first_line = slineno |
| # Check whether to end an excluded suite. |
| if excluding and indent <= exclude_indent: |
| excluding = False |
| if excluding: |
| self.excluded.add(elineno) |
| |
| # Find the starts of the executable statements. |
| if not empty: |
| byte_parser = ByteParser(self.text, filename=self.filename) |
| self.raw_statements.update(byte_parser._find_statements()) |
| |
| # The first line of modules can lie and say 1 always, even if the first |
| # line of code is later. If so, map 1 to the actual first line of the |
| # module. |
| if env.PYBEHAVIOR.module_firstline_1 and self._multiline: |
| self._multiline[1] = min(self.raw_statements) |
| |
| self.excluded = self.first_lines(self.excluded) |
| |
| # AST lets us find classes, docstrings, and decorator-affected |
| # functions and classes. |
| assert self._ast_root is not None |
| for node in ast.walk(self._ast_root): |
| # Find class definitions. |
| if isinstance(node, ast.ClassDef): |
| self.raw_classdefs.add(node.lineno) |
| # Find docstrings. |
| if isinstance(node, (ast.ClassDef, ast.FunctionDef, ast.AsyncFunctionDef, ast.Module)): |
| if node.body: |
| first = node.body[0] |
| if ( |
| isinstance(first, ast.Expr) |
| and isinstance(first.value, ast.Constant) |
| and isinstance(first.value.value, str) |
| ): |
| self.raw_docstrings.update( |
| range(first.lineno, cast(int, first.end_lineno) + 1) |
| ) |
| # Exclusions carry from decorators and signatures to the bodies of |
| # functions and classes. |
| if isinstance(node, (ast.ClassDef, ast.FunctionDef, ast.AsyncFunctionDef)): |
| first_line = min((d.lineno for d in node.decorator_list), default=node.lineno) |
| if self.excluded.intersection(range(first_line, node.lineno + 1)): |
| self.excluded.update(range(first_line, cast(int, node.end_lineno) + 1)) |
| |
| @functools.lru_cache(maxsize=1000) |
| def first_line(self, lineno: TLineNo) -> TLineNo: |
| """Return the first line number of the statement including `lineno`.""" |
| if lineno < 0: |
| lineno = -self._multiline.get(-lineno, -lineno) |
| else: |
| lineno = self._multiline.get(lineno, lineno) |
| return lineno |
| |
| def first_lines(self, linenos: Iterable[TLineNo]) -> set[TLineNo]: |
| """Map the line numbers in `linenos` to the correct first line of the |
| statement. |
| |
| Returns a set of the first lines. |
| |
| """ |
| return {self.first_line(l) for l in linenos} |
| |
| def translate_lines(self, lines: Iterable[TLineNo]) -> set[TLineNo]: |
| """Implement `FileReporter.translate_lines`.""" |
| return self.first_lines(lines) |
| |
| def translate_arcs(self, arcs: Iterable[TArc]) -> set[TArc]: |
| """Implement `FileReporter.translate_arcs`.""" |
| return {(self.first_line(a), self.first_line(b)) for (a, b) in arcs} |
| |
| def parse_source(self) -> None: |
| """Parse source text to find executable lines, excluded lines, etc. |
| |
| Sets the .excluded and .statements attributes, normalized to the first |
| line of multi-line statements. |
| |
| """ |
| try: |
| self._ast_root = ast.parse(self.text) |
| self._raw_parse() |
| except (tokenize.TokenError, IndentationError, SyntaxError) as err: |
| if hasattr(err, "lineno"): |
| lineno = err.lineno # IndentationError |
| else: |
| lineno = err.args[1][0] # TokenError |
| raise NotPython( |
| f"Couldn't parse '{self.filename}' as Python source: " + |
| f"{err.args[0]!r} at line {lineno}", |
| ) from err |
| |
| ignore = self.excluded | self.raw_docstrings |
| starts = self.raw_statements - ignore |
| self.statements = self.first_lines(starts) - ignore |
| |
| def arcs(self) -> set[TArc]: |
| """Get information about the arcs available in the code. |
| |
| Returns a set of line number pairs. Line numbers have been normalized |
| to the first line of multi-line statements. |
| |
| """ |
| if self._all_arcs is None: |
| self._analyze_ast() |
| assert self._all_arcs is not None |
| return self._all_arcs |
| |
| def _analyze_ast(self) -> None: |
| """Run the AstArcAnalyzer and save its results. |
| |
| `_all_arcs` is the set of arcs in the code. |
| |
| """ |
| assert self._ast_root is not None |
| aaa = AstArcAnalyzer(self._ast_root, self.raw_statements, self._multiline) |
| aaa.analyze() |
| |
| self._all_arcs = set() |
| for l1, l2 in aaa.arcs: |
| fl1 = self.first_line(l1) |
| fl2 = self.first_line(l2) |
| if fl1 != fl2: |
| self._all_arcs.add((fl1, fl2)) |
| |
| self._missing_arc_fragments = aaa.missing_arc_fragments |
| |
| @functools.lru_cache() |
| def exit_counts(self) -> dict[TLineNo, int]: |
| """Get a count of exits from that each line. |
| |
| Excluded lines are excluded. |
| |
| """ |
| exit_counts: dict[TLineNo, int] = collections.defaultdict(int) |
| for l1, l2 in self.arcs(): |
| if l1 < 0: |
| # Don't ever report -1 as a line number |
| continue |
| if l1 in self.excluded: |
| # Don't report excluded lines as line numbers. |
| continue |
| if l2 in self.excluded: |
| # Arcs to excluded lines shouldn't count. |
| continue |
| exit_counts[l1] += 1 |
| |
| # Class definitions have one extra exit, so remove one for each: |
| for l in self.raw_classdefs: |
| # Ensure key is there: class definitions can include excluded lines. |
| if l in exit_counts: |
| exit_counts[l] -= 1 |
| |
| return exit_counts |
| |
| def missing_arc_description( |
| self, |
| start: TLineNo, |
| end: TLineNo, |
| executed_arcs: Iterable[TArc] | None = None, |
| ) -> str: |
| """Provide an English sentence describing a missing arc.""" |
| if self._missing_arc_fragments is None: |
| self._analyze_ast() |
| assert self._missing_arc_fragments is not None |
| |
| actual_start = start |
| |
| if ( |
| executed_arcs and |
| end < 0 and end == -start and |
| (end, start) not in executed_arcs and |
| (end, start) in self._missing_arc_fragments |
| ): |
| # It's a one-line callable, and we never even started it, |
| # and we have a message about not starting it. |
| start, end = end, start |
| |
| fragment_pairs = self._missing_arc_fragments.get((start, end), [(None, None)]) |
| |
| msgs = [] |
| for smsg, emsg in fragment_pairs: |
| if emsg is None: |
| if end < 0: |
| # Hmm, maybe we have a one-line callable, let's check. |
| if (-end, end) in self._missing_arc_fragments: |
| return self.missing_arc_description(-end, end) |
| emsg = "didn't jump to the function exit" |
| else: |
| emsg = "didn't jump to line {lineno}" |
| emsg = emsg.format(lineno=end) |
| |
| msg = f"line {actual_start} {emsg}" |
| if smsg is not None: |
| msg += f" because {smsg.format(lineno=actual_start)}" |
| |
| msgs.append(msg) |
| |
| return " or ".join(msgs) |
| |
| |
| class ByteParser: |
| """Parse bytecode to understand the structure of code.""" |
| |
| def __init__( |
| self, |
| text: str, |
| code: CodeType | None = None, |
| filename: str | None = None, |
| ) -> None: |
| self.text = text |
| if code is not None: |
| self.code = code |
| else: |
| assert filename is not None |
| # We only get here if earlier ast parsing succeeded, so no need to |
| # catch errors. |
| self.code = compile(text, filename, "exec", dont_inherit=True) |
| |
| def child_parsers(self) -> Iterable[ByteParser]: |
| """Iterate over all the code objects nested within this one. |
| |
| The iteration includes `self` as its first value. |
| |
| """ |
| return (ByteParser(self.text, code=c) for c in code_objects(self.code)) |
| |
| def _line_numbers(self) -> Iterable[TLineNo]: |
| """Yield the line numbers possible in this code object. |
| |
| Uses co_lnotab described in Python/compile.c to find the |
| line numbers. Produces a sequence: l0, l1, ... |
| """ |
| if hasattr(self.code, "co_lines"): |
| # PYVERSIONS: new in 3.10 |
| for _, _, line in self.code.co_lines(): |
| if line: |
| yield line |
| else: |
| # Adapted from dis.py in the standard library. |
| byte_increments = self.code.co_lnotab[0::2] |
| line_increments = self.code.co_lnotab[1::2] |
| |
| last_line_num = None |
| line_num = self.code.co_firstlineno |
| byte_num = 0 |
| for byte_incr, line_incr in zip(byte_increments, line_increments): |
| if byte_incr: |
| if line_num != last_line_num: |
| yield line_num |
| last_line_num = line_num |
| byte_num += byte_incr |
| if line_incr >= 0x80: |
| line_incr -= 0x100 |
| line_num += line_incr |
| if line_num != last_line_num: |
| yield line_num |
| |
| def _find_statements(self) -> Iterable[TLineNo]: |
| """Find the statements in `self.code`. |
| |
| Produce a sequence of line numbers that start statements. Recurses |
| into all code objects reachable from `self.code`. |
| |
| """ |
| for bp in self.child_parsers(): |
| # Get all of the lineno information from this code. |
| yield from bp._line_numbers() |
| |
| |
| # |
| # AST analysis |
| # |
| |
| @dataclass(frozen=True, order=True) |
| class ArcStart: |
| """The information needed to start an arc. |
| |
| `lineno` is the line number the arc starts from. |
| |
| `cause` is an English text fragment used as the `startmsg` for |
| AstArcAnalyzer.missing_arc_fragments. It will be used to describe why an |
| arc wasn't executed, so should fit well into a sentence of the form, |
| "Line 17 didn't run because {cause}." The fragment can include "{lineno}" |
| to have `lineno` interpolated into it. |
| |
| As an example, this code:: |
| |
| if something(x): # line 1 |
| func(x) # line 2 |
| more_stuff() # line 3 |
| |
| would have two ArcStarts: |
| |
| - ArcStart(1, "the condition on line 1 was always true") |
| - ArcStart(1, "the condition on line 1 was never true") |
| |
| The first would be used to create an arc from 1 to 3, creating a message like |
| "line 1 didn't jump to line 3 because the condition on line 1 was always true." |
| |
| The second would be used for the arc from 1 to 2, creating a message like |
| "line 1 didn't jump to line 2 because the condition on line 1 was never true." |
| |
| """ |
| lineno: TLineNo |
| cause: str = "" |
| |
| |
| class TAddArcFn(Protocol): |
| """The type for AstArcAnalyzer.add_arc().""" |
| def __call__( |
| self, |
| start: TLineNo, |
| end: TLineNo, |
| smsg: str | None = None, |
| emsg: str | None = None, |
| ) -> None: |
| ... |
| |
| TArcFragments = Dict[TArc, List[Tuple[Optional[str], Optional[str]]]] |
| |
| class Block: |
| """ |
| Blocks need to handle various exiting statements in their own ways. |
| |
| All of these methods take a list of exits, and a callable `add_arc` |
| function that they can use to add arcs if needed. They return True if the |
| exits are handled, or False if the search should continue up the block |
| stack. |
| """ |
| # pylint: disable=unused-argument |
| def process_break_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| """Process break exits.""" |
| # Because break can only appear in loops, and most subclasses |
| # implement process_break_exits, this function is never reached. |
| raise AssertionError |
| |
| def process_continue_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| """Process continue exits.""" |
| # Because continue can only appear in loops, and most subclasses |
| # implement process_continue_exits, this function is never reached. |
| raise AssertionError |
| |
| def process_raise_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| """Process raise exits.""" |
| return False |
| |
| def process_return_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| """Process return exits.""" |
| return False |
| |
| |
| class LoopBlock(Block): |
| """A block on the block stack representing a `for` or `while` loop.""" |
| def __init__(self, start: TLineNo) -> None: |
| # The line number where the loop starts. |
| self.start = start |
| # A set of ArcStarts, the arcs from break statements exiting this loop. |
| self.break_exits: set[ArcStart] = set() |
| |
| def process_break_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| self.break_exits.update(exits) |
| return True |
| |
| def process_continue_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| for xit in exits: |
| add_arc(xit.lineno, self.start, xit.cause) |
| return True |
| |
| |
| class FunctionBlock(Block): |
| """A block on the block stack representing a function definition.""" |
| def __init__(self, start: TLineNo, name: str) -> None: |
| # The line number where the function starts. |
| self.start = start |
| # The name of the function. |
| self.name = name |
| |
| def process_raise_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| for xit in exits: |
| add_arc( |
| xit.lineno, -self.start, xit.cause, |
| f"didn't except from function {self.name!r}", |
| ) |
| return True |
| |
| def process_return_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| for xit in exits: |
| add_arc( |
| xit.lineno, -self.start, xit.cause, |
| f"didn't return from function {self.name!r}", |
| ) |
| return True |
| |
| |
| class TryBlock(Block): |
| """A block on the block stack representing a `try` block.""" |
| def __init__(self, handler_start: TLineNo | None, final_start: TLineNo | None) -> None: |
| # The line number of the first "except" handler, if any. |
| self.handler_start = handler_start |
| # The line number of the "finally:" clause, if any. |
| self.final_start = final_start |
| |
| # The ArcStarts for breaks/continues/returns/raises inside the "try:" |
| # that need to route through the "finally:" clause. |
| self.break_from: set[ArcStart] = set() |
| self.continue_from: set[ArcStart] = set() |
| self.raise_from: set[ArcStart] = set() |
| self.return_from: set[ArcStart] = set() |
| |
| def process_break_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| if self.final_start is not None: |
| self.break_from.update(exits) |
| return True |
| return False |
| |
| def process_continue_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| if self.final_start is not None: |
| self.continue_from.update(exits) |
| return True |
| return False |
| |
| def process_raise_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| if self.handler_start is not None: |
| for xit in exits: |
| add_arc(xit.lineno, self.handler_start, xit.cause) |
| else: |
| assert self.final_start is not None |
| self.raise_from.update(exits) |
| return True |
| |
| def process_return_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| if self.final_start is not None: |
| self.return_from.update(exits) |
| return True |
| return False |
| |
| |
| class WithBlock(Block): |
| """A block on the block stack representing a `with` block.""" |
| def __init__(self, start: TLineNo) -> None: |
| # We only ever use this block if it is needed, so that we don't have to |
| # check this setting in all the methods. |
| assert env.PYBEHAVIOR.exit_through_with |
| |
| # The line number of the with statement. |
| self.start = start |
| |
| # The ArcStarts for breaks/continues/returns/raises inside the "with:" |
| # that need to go through the with-statement while exiting. |
| self.break_from: set[ArcStart] = set() |
| self.continue_from: set[ArcStart] = set() |
| self.return_from: set[ArcStart] = set() |
| |
| def _process_exits( |
| self, |
| exits: set[ArcStart], |
| add_arc: TAddArcFn, |
| from_set: set[ArcStart] | None = None, |
| ) -> bool: |
| """Helper to process the four kinds of exits.""" |
| for xit in exits: |
| add_arc(xit.lineno, self.start, xit.cause) |
| if from_set is not None: |
| from_set.update(exits) |
| return True |
| |
| def process_break_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| return self._process_exits(exits, add_arc, self.break_from) |
| |
| def process_continue_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| return self._process_exits(exits, add_arc, self.continue_from) |
| |
| def process_raise_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| return self._process_exits(exits, add_arc) |
| |
| def process_return_exits(self, exits: set[ArcStart], add_arc: TAddArcFn) -> bool: |
| return self._process_exits(exits, add_arc, self.return_from) |
| |
| |
| class NodeList(ast.AST): |
| """A synthetic fictitious node, containing a sequence of nodes. |
| |
| This is used when collapsing optimized if-statements, to represent the |
| unconditional execution of one of the clauses. |
| |
| """ |
| def __init__(self, body: Sequence[ast.AST]) -> None: |
| self.body = body |
| self.lineno = body[0].lineno |
| |
| # TODO: Shouldn't the cause messages join with "and" instead of "or"? |
| |
| def _make_expression_code_method(noun: str) -> Callable[[AstArcAnalyzer, ast.AST], None]: |
| """A function to make methods for expression-based callable _code_object__ methods.""" |
| def _code_object__expression_callable(self: AstArcAnalyzer, node: ast.AST) -> None: |
| start = self.line_for_node(node) |
| self.add_arc(-start, start, None, f"didn't run the {noun} on line {start}") |
| self.add_arc(start, -start, None, f"didn't finish the {noun} on line {start}") |
| return _code_object__expression_callable |
| |
| |
| class AstArcAnalyzer: |
| """Analyze source text with an AST to find executable code paths. |
| |
| The .analyze() method does the work, and populates these attributes: |
| |
| `arcs`: a set of (from, to) pairs of the the arcs possible in the code. |
| |
| `missing_arc_fragments`: a dict mapping (from, to) arcs to lists of |
| message fragments explaining why the arc is missing from execution:: |
| |
| { (start, end): [(startmsg, endmsg), ...], } |
| |
| For an arc starting from line 17, they should be usable to form complete |
| sentences like: "Line 17 {endmsg} because {startmsg}". |
| |
| """ |
| |
| def __init__( |
| self, |
| root_node: ast.AST, |
| statements: set[TLineNo], |
| multiline: dict[TLineNo, TLineNo], |
| ) -> None: |
| self.root_node = root_node |
| # TODO: I think this is happening in too many places. |
| self.statements = {multiline.get(l, l) for l in statements} |
| self.multiline = multiline |
| |
| # Turn on AST dumps with an environment variable. |
| # $set_env.py: COVERAGE_AST_DUMP - Dump the AST nodes when parsing code. |
| dump_ast = bool(int(os.getenv("COVERAGE_AST_DUMP", "0"))) |
| |
| if dump_ast: # pragma: debugging |
| # Dump the AST so that failing tests have helpful output. |
| print(f"Statements: {self.statements}") |
| print(f"Multiline map: {self.multiline}") |
| dumpkw: dict[str, Any] = {} |
| if sys.version_info >= (3, 9): |
| dumpkw["indent"] = 4 |
| print(ast.dump(self.root_node, include_attributes=True, **dumpkw)) |
| |
| self.arcs: set[TArc] = set() |
| self.missing_arc_fragments: TArcFragments = collections.defaultdict(list) |
| self.block_stack: list[Block] = [] |
| |
| # $set_env.py: COVERAGE_TRACK_ARCS - Trace possible arcs added while parsing code. |
| self.debug = bool(int(os.getenv("COVERAGE_TRACK_ARCS", "0"))) |
| |
| def analyze(self) -> None: |
| """Examine the AST tree from `self.root_node` to determine possible arcs.""" |
| for node in ast.walk(self.root_node): |
| node_name = node.__class__.__name__ |
| code_object_handler = getattr(self, "_code_object__" + node_name, None) |
| if code_object_handler is not None: |
| code_object_handler(node) |
| |
| # Code object dispatchers: _code_object__* |
| # |
| # These methods are used by analyze() as the start of the analysis. |
| # There is one for each construct with a code object. |
| |
| def _code_object__Module(self, node: ast.Module) -> None: |
| start = self.line_for_node(node) |
| if node.body: |
| exits = self.body_exits(node.body, from_start=ArcStart(-start)) |
| for xit in exits: |
| self.add_arc(xit.lineno, -start, xit.cause, "didn't exit the module") |
| else: |
| # Empty module. |
| self.add_arc(-start, start) |
| self.add_arc(start, -start) |
| |
| def _code_object__FunctionDef(self, node: ast.FunctionDef) -> None: |
| start = self.line_for_node(node) |
| self.block_stack.append(FunctionBlock(start=start, name=node.name)) |
| exits = self.body_exits(node.body, from_start=ArcStart(-start)) |
| self.process_return_exits(exits) |
| self.block_stack.pop() |
| |
| _code_object__AsyncFunctionDef = _code_object__FunctionDef |
| |
| def _code_object__ClassDef(self, node: ast.ClassDef) -> None: |
| start = self.line_for_node(node) |
| self.add_arc(-start, start) |
| exits = self.body_exits(node.body, from_start=ArcStart(start)) |
| for xit in exits: |
| self.add_arc( |
| xit.lineno, -start, xit.cause, |
| f"didn't exit the body of class {node.name!r}", |
| ) |
| |
| _code_object__Lambda = _make_expression_code_method("lambda") |
| _code_object__GeneratorExp = _make_expression_code_method("generator expression") |
| if env.PYBEHAVIOR.comprehensions_are_functions: |
| _code_object__DictComp = _make_expression_code_method("dictionary comprehension") |
| _code_object__SetComp = _make_expression_code_method("set comprehension") |
| _code_object__ListComp = _make_expression_code_method("list comprehension") |
| |
| |
| def add_arc( |
| self, |
| start: TLineNo, |
| end: TLineNo, |
| smsg: str | None = None, |
| emsg: str | None = None, |
| ) -> None: |
| """Add an arc, including message fragments to use if it is missing.""" |
| if self.debug: # pragma: debugging |
| print(f"\nAdding possible arc: ({start}, {end}): {smsg!r}, {emsg!r}") |
| print(short_stack()) |
| self.arcs.add((start, end)) |
| |
| if smsg is not None or emsg is not None: |
| self.missing_arc_fragments[(start, end)].append((smsg, emsg)) |
| |
| def nearest_blocks(self) -> Iterable[Block]: |
| """Yield the blocks in nearest-to-farthest order.""" |
| return reversed(self.block_stack) |
| |
| def line_for_node(self, node: ast.AST) -> TLineNo: |
| """What is the right line number to use for this node? |
| |
| This dispatches to _line__Node functions where needed. |
| |
| """ |
| node_name = node.__class__.__name__ |
| handler = cast( |
| Optional[Callable[[ast.AST], TLineNo]], |
| getattr(self, "_line__" + node_name, None), |
| ) |
| if handler is not None: |
| return handler(node) |
| else: |
| return node.lineno |
| |
| # First lines: _line__* |
| # |
| # Dispatched by line_for_node, each method knows how to identify the first |
| # line number in the node, as Python will report it. |
| |
| def _line_decorated(self, node: ast.FunctionDef) -> TLineNo: |
| """Compute first line number for things that can be decorated (classes and functions).""" |
| if node.decorator_list: |
| lineno = node.decorator_list[0].lineno |
| else: |
| lineno = node.lineno |
| return lineno |
| |
| def _line__Assign(self, node: ast.Assign) -> TLineNo: |
| return self.line_for_node(node.value) |
| |
| _line__ClassDef = _line_decorated |
| |
| def _line__Dict(self, node: ast.Dict) -> TLineNo: |
| if node.keys: |
| if node.keys[0] is not None: |
| return node.keys[0].lineno |
| else: |
| # Unpacked dict literals `{**{"a":1}}` have None as the key, |
| # use the value in that case. |
| return node.values[0].lineno |
| else: |
| return node.lineno |
| |
| _line__FunctionDef = _line_decorated |
| _line__AsyncFunctionDef = _line_decorated |
| |
| def _line__List(self, node: ast.List) -> TLineNo: |
| if node.elts: |
| return self.line_for_node(node.elts[0]) |
| else: |
| return node.lineno |
| |
| def _line__Module(self, node: ast.Module) -> TLineNo: |
| if env.PYBEHAVIOR.module_firstline_1: |
| return 1 |
| elif node.body: |
| return self.line_for_node(node.body[0]) |
| else: |
| # Empty modules have no line number, they always start at 1. |
| return 1 |
| |
| # The node types that just flow to the next node with no complications. |
| OK_TO_DEFAULT = { |
| "AnnAssign", "Assign", "Assert", "AugAssign", "Delete", "Expr", "Global", |
| "Import", "ImportFrom", "Nonlocal", "Pass", |
| } |
| |
| def node_exits(self, node: ast.AST) -> set[ArcStart]: |
| """Find the set of arc starts that exit this node. |
| |
| Return a set of ArcStarts, exits from this node to the next. Because a |
| node represents an entire sub-tree (including its children), the exits |
| from a node can be arbitrarily complex:: |
| |
| if something(1): |
| if other(2): |
| doit(3) |
| else: |
| doit(5) |
| |
| There are three exits from line 1: they start at lines 1, 3 and 5. |
| There are two exits from line 2: lines 3 and 5. |
| |
| """ |
| node_name = node.__class__.__name__ |
| handler = cast( |
| Optional[Callable[[ast.AST], Set[ArcStart]]], |
| getattr(self, "_handle__" + node_name, None), |
| ) |
| if handler is not None: |
| arc_starts = handler(node) |
| else: |
| # No handler: either it's something that's ok to default (a simple |
| # statement), or it's something we overlooked. |
| if env.TESTING: |
| if node_name not in self.OK_TO_DEFAULT: |
| raise RuntimeError(f"*** Unhandled: {node}") # pragma: only failure |
| |
| # Default for simple statements: one exit from this node. |
| arc_starts = {ArcStart(self.line_for_node(node))} |
| return arc_starts |
| |
| def body_exits( |
| self, |
| body: Sequence[ast.AST], |
| from_start: ArcStart | None = None, |
| prev_starts: set[ArcStart] | None = None, |
| ) -> set[ArcStart]: |
| """Find arc starts that exit the body of a compound statement. |
| |
| `body` is the body node. `from_start` is a single `ArcStart` that can |
| be the previous line in flow before this body. `prev_starts` is a set |
| of ArcStarts that can be the previous line. Only one of them should be |
| given. |
| |
| Also records arcs (using `add_arc`) within the body. |
| |
| Returns a set of ArcStarts, the exits from this body. |
| |
| """ |
| if prev_starts is None: |
| assert from_start is not None |
| prev_starts = {from_start} |
| else: |
| assert from_start is None |
| |
| # Loop over the nodes in the body, making arcs from each one's exits to |
| # the next node. |
| for body_node in body: |
| lineno = self.line_for_node(body_node) |
| first_line = self.multiline.get(lineno, lineno) |
| if first_line not in self.statements: |
| maybe_body_node = self.find_non_missing_node(body_node) |
| if maybe_body_node is None: |
| continue |
| body_node = maybe_body_node |
| lineno = self.line_for_node(body_node) |
| for prev_start in prev_starts: |
| self.add_arc(prev_start.lineno, lineno, prev_start.cause) |
| prev_starts = self.node_exits(body_node) |
| return prev_starts |
| |
| def find_non_missing_node(self, node: ast.AST) -> ast.AST | None: |
| """Search `node` looking for a child that has not been optimized away. |
| |
| This might return the node you started with, or it will work recursively |
| to find a child node in self.statements. |
| |
| Returns a node, or None if none of the node remains. |
| |
| """ |
| # This repeats work just done in body_exits, but this duplication |
| # means we can avoid a function call in the 99.9999% case of not |
| # optimizing away statements. |
| lineno = self.line_for_node(node) |
| first_line = self.multiline.get(lineno, lineno) |
| if first_line in self.statements: |
| return node |
| |
| missing_fn = cast( |
| Optional[Callable[[ast.AST], Optional[ast.AST]]], |
| getattr(self, "_missing__" + node.__class__.__name__, None), |
| ) |
| if missing_fn is not None: |
| ret_node = missing_fn(node) |
| else: |
| ret_node = None |
| return ret_node |
| |
| # Missing nodes: _missing__* |
| # |
| # Entire statements can be optimized away by Python. They will appear in |
| # the AST, but not the bytecode. These functions are called (by |
| # find_non_missing_node) to find a node to use instead of the missing |
| # node. They can return None if the node should truly be gone. |
| |
| def _missing__If(self, node: ast.If) -> ast.AST | None: |
| # If the if-node is missing, then one of its children might still be |
| # here, but not both. So return the first of the two that isn't missing. |
| # Use a NodeList to hold the clauses as a single node. |
| non_missing = self.find_non_missing_node(NodeList(node.body)) |
| if non_missing: |
| return non_missing |
| if node.orelse: |
| return self.find_non_missing_node(NodeList(node.orelse)) |
| return None |
| |
| def _missing__NodeList(self, node: NodeList) -> ast.AST | None: |
| # A NodeList might be a mixture of missing and present nodes. Find the |
| # ones that are present. |
| non_missing_children = [] |
| for child in node.body: |
| maybe_child = self.find_non_missing_node(child) |
| if maybe_child is not None: |
| non_missing_children.append(maybe_child) |
| |
| # Return the simplest representation of the present children. |
| if not non_missing_children: |
| return None |
| if len(non_missing_children) == 1: |
| return non_missing_children[0] |
| return NodeList(non_missing_children) |
| |
| def _missing__While(self, node: ast.While) -> ast.AST | None: |
| body_nodes = self.find_non_missing_node(NodeList(node.body)) |
| if not body_nodes: |
| return None |
| # Make a synthetic While-true node. |
| new_while = ast.While() |
| new_while.lineno = body_nodes.lineno |
| new_while.test = ast.Name() |
| new_while.test.lineno = body_nodes.lineno |
| new_while.test.id = "True" |
| assert hasattr(body_nodes, "body") |
| new_while.body = body_nodes.body |
| new_while.orelse = [] |
| return new_while |
| |
| def is_constant_expr(self, node: ast.AST) -> str | None: |
| """Is this a compile-time constant?""" |
| node_name = node.__class__.__name__ |
| if node_name in ["Constant", "NameConstant", "Num"]: |
| return "Num" |
| elif isinstance(node, ast.Name): |
| if node.id in ["True", "False", "None", "__debug__"]: |
| return "Name" |
| return None |
| |
| # In the fullness of time, these might be good tests to write: |
| # while EXPR: |
| # while False: |
| # listcomps hidden deep in other expressions |
| # listcomps hidden in lists: x = [[i for i in range(10)]] |
| # nested function definitions |
| |
| # Exit processing: process_*_exits |
| # |
| # These functions process the four kinds of jump exits: break, continue, |
| # raise, and return. To figure out where an exit goes, we have to look at |
| # the block stack context. For example, a break will jump to the nearest |
| # enclosing loop block, or the nearest enclosing finally block, whichever |
| # is nearer. |
| |
| def process_break_exits(self, exits: set[ArcStart]) -> None: |
| """Add arcs due to jumps from `exits` being breaks.""" |
| for block in self.nearest_blocks(): # pragma: always breaks |
| if block.process_break_exits(exits, self.add_arc): |
| break |
| |
| def process_continue_exits(self, exits: set[ArcStart]) -> None: |
| """Add arcs due to jumps from `exits` being continues.""" |
| for block in self.nearest_blocks(): # pragma: always breaks |
| if block.process_continue_exits(exits, self.add_arc): |
| break |
| |
| def process_raise_exits(self, exits: set[ArcStart]) -> None: |
| """Add arcs due to jumps from `exits` being raises.""" |
| for block in self.nearest_blocks(): |
| if block.process_raise_exits(exits, self.add_arc): |
| break |
| |
| def process_return_exits(self, exits: set[ArcStart]) -> None: |
| """Add arcs due to jumps from `exits` being returns.""" |
| for block in self.nearest_blocks(): # pragma: always breaks |
| if block.process_return_exits(exits, self.add_arc): |
| break |
| |
| # Node handlers: _handle__* |
| # |
| # Each handler deals with a specific AST node type, dispatched from |
| # node_exits. Handlers return the set of exits from that node, and can |
| # also call self.add_arc to record arcs they find. These functions mirror |
| # the Python semantics of each syntactic construct. See the docstring |
| # for node_exits to understand the concept of exits from a node. |
| # |
| # Every node type that represents a statement should have a handler, or it |
| # should be listed in OK_TO_DEFAULT. |
| |
| def _handle__Break(self, node: ast.Break) -> set[ArcStart]: |
| here = self.line_for_node(node) |
| break_start = ArcStart(here, cause="the break on line {lineno} wasn't executed") |
| self.process_break_exits({break_start}) |
| return set() |
| |
| def _handle_decorated(self, node: ast.FunctionDef) -> set[ArcStart]: |
| """Add arcs for things that can be decorated (classes and functions).""" |
| main_line: TLineNo = node.lineno |
| last: TLineNo | None = node.lineno |
| decs = node.decorator_list |
| if decs: |
| last = None |
| for dec_node in decs: |
| dec_start = self.line_for_node(dec_node) |
| if last is not None and dec_start != last: # type: ignore[unreachable] |
| self.add_arc(last, dec_start) # type: ignore[unreachable] |
| last = dec_start |
| assert last is not None |
| self.add_arc(last, main_line) |
| last = main_line |
| if env.PYBEHAVIOR.trace_decorator_line_again: |
| for top, bot in zip(decs, decs[1:]): |
| self.add_arc(self.line_for_node(bot), self.line_for_node(top)) |
| self.add_arc(self.line_for_node(decs[0]), main_line) |
| self.add_arc(main_line, self.line_for_node(decs[-1])) |
| # The definition line may have been missed, but we should have it |
| # in `self.statements`. For some constructs, `line_for_node` is |
| # not what we'd think of as the first line in the statement, so map |
| # it to the first one. |
| if node.body: |
| body_start = self.line_for_node(node.body[0]) |
| body_start = self.multiline.get(body_start, body_start) |
| # The body is handled in collect_arcs. |
| assert last is not None |
| return {ArcStart(last)} |
| |
| _handle__ClassDef = _handle_decorated |
| |
| def _handle__Continue(self, node: ast.Continue) -> set[ArcStart]: |
| here = self.line_for_node(node) |
| continue_start = ArcStart(here, cause="the continue on line {lineno} wasn't executed") |
| self.process_continue_exits({continue_start}) |
| return set() |
| |
| def _handle__For(self, node: ast.For) -> set[ArcStart]: |
| start = self.line_for_node(node.iter) |
| self.block_stack.append(LoopBlock(start=start)) |
| from_start = ArcStart(start, cause="the loop on line {lineno} never started") |
| exits = self.body_exits(node.body, from_start=from_start) |
| # Any exit from the body will go back to the top of the loop. |
| for xit in exits: |
| self.add_arc(xit.lineno, start, xit.cause) |
| my_block = self.block_stack.pop() |
| assert isinstance(my_block, LoopBlock) |
| exits = my_block.break_exits |
| from_start = ArcStart(start, cause="the loop on line {lineno} didn't complete") |
| if node.orelse: |
| else_exits = self.body_exits(node.orelse, from_start=from_start) |
| exits |= else_exits |
| else: |
| # No else clause: exit from the for line. |
| exits.add(from_start) |
| return exits |
| |
| _handle__AsyncFor = _handle__For |
| |
| _handle__FunctionDef = _handle_decorated |
| _handle__AsyncFunctionDef = _handle_decorated |
| |
| def _handle__If(self, node: ast.If) -> set[ArcStart]: |
| start = self.line_for_node(node.test) |
| from_start = ArcStart(start, cause="the condition on line {lineno} was never true") |
| exits = self.body_exits(node.body, from_start=from_start) |
| from_start = ArcStart(start, cause="the condition on line {lineno} was always true") |
| exits |= self.body_exits(node.orelse, from_start=from_start) |
| return exits |
| |
| if sys.version_info >= (3, 10): |
| def _handle__Match(self, node: ast.Match) -> set[ArcStart]: |
| start = self.line_for_node(node) |
| last_start = start |
| exits = set() |
| for case in node.cases: |
| case_start = self.line_for_node(case.pattern) |
| self.add_arc(last_start, case_start, "the pattern on line {lineno} always matched") |
| from_start = ArcStart( |
| case_start, |
| cause="the pattern on line {lineno} never matched", |
| ) |
| exits |= self.body_exits(case.body, from_start=from_start) |
| last_start = case_start |
| |
| # case is now the last case, check for wildcard match. |
| pattern = case.pattern # pylint: disable=undefined-loop-variable |
| while isinstance(pattern, ast.MatchOr): |
| pattern = pattern.patterns[-1] |
| had_wildcard = ( |
| isinstance(pattern, ast.MatchAs) |
| and pattern.pattern is None |
| and case.guard is None # pylint: disable=undefined-loop-variable |
| ) |
| |
| if not had_wildcard: |
| exits.add( |
| ArcStart(case_start, cause="the pattern on line {lineno} always matched"), |
| ) |
| return exits |
| |
| def _handle__NodeList(self, node: NodeList) -> set[ArcStart]: |
| start = self.line_for_node(node) |
| exits = self.body_exits(node.body, from_start=ArcStart(start)) |
| return exits |
| |
| def _handle__Raise(self, node: ast.Raise) -> set[ArcStart]: |
| here = self.line_for_node(node) |
| raise_start = ArcStart(here, cause="the raise on line {lineno} wasn't executed") |
| self.process_raise_exits({raise_start}) |
| # `raise` statement jumps away, no exits from here. |
| return set() |
| |
| def _handle__Return(self, node: ast.Return) -> set[ArcStart]: |
| here = self.line_for_node(node) |
| return_start = ArcStart(here, cause="the return on line {lineno} wasn't executed") |
| self.process_return_exits({return_start}) |
| # `return` statement jumps away, no exits from here. |
| return set() |
| |
| def _handle__Try(self, node: ast.Try) -> set[ArcStart]: |
| if node.handlers: |
| handler_start = self.line_for_node(node.handlers[0]) |
| else: |
| handler_start = None |
| |
| if node.finalbody: |
| final_start = self.line_for_node(node.finalbody[0]) |
| else: |
| final_start = None |
| |
| # This is true by virtue of Python syntax: have to have either except |
| # or finally, or both. |
| assert handler_start is not None or final_start is not None |
| try_block = TryBlock(handler_start, final_start) |
| self.block_stack.append(try_block) |
| |
| start = self.line_for_node(node) |
| exits = self.body_exits(node.body, from_start=ArcStart(start)) |
| |
| # We're done with the `try` body, so this block no longer handles |
| # exceptions. We keep the block so the `finally` clause can pick up |
| # flows from the handlers and `else` clause. |
| if node.finalbody: |
| try_block.handler_start = None |
| if node.handlers: |
| # If there are `except` clauses, then raises in the try body |
| # will already jump to them. Start this set over for raises in |
| # `except` and `else`. |
| try_block.raise_from = set() |
| else: |
| self.block_stack.pop() |
| |
| handler_exits: set[ArcStart] = set() |
| |
| if node.handlers: |
| last_handler_start: TLineNo | None = None |
| for handler_node in node.handlers: |
| handler_start = self.line_for_node(handler_node) |
| if last_handler_start is not None: |
| self.add_arc(last_handler_start, handler_start) |
| last_handler_start = handler_start |
| from_cause = "the exception caught by line {lineno} didn't happen" |
| from_start = ArcStart(handler_start, cause=from_cause) |
| handler_exits |= self.body_exits(handler_node.body, from_start=from_start) |
| |
| if node.orelse: |
| exits = self.body_exits(node.orelse, prev_starts=exits) |
| |
| exits |= handler_exits |
| |
| if node.finalbody: |
| self.block_stack.pop() |
| final_from = ( # You can get to the `finally` clause from: |
| exits | # the exits of the body or `else` clause, |
| try_block.break_from | # or a `break`, |
| try_block.continue_from | # or a `continue`, |
| try_block.raise_from | # or a `raise`, |
| try_block.return_from # or a `return`. |
| ) |
| |
| final_exits = self.body_exits(node.finalbody, prev_starts=final_from) |
| |
| if try_block.break_from: |
| if env.PYBEHAVIOR.finally_jumps_back: |
| for break_line in try_block.break_from: |
| lineno = break_line.lineno |
| cause = break_line.cause.format(lineno=lineno) |
| for final_exit in final_exits: |
| self.add_arc(final_exit.lineno, lineno, cause) |
| breaks = try_block.break_from |
| else: |
| breaks = self._combine_finally_starts(try_block.break_from, final_exits) |
| self.process_break_exits(breaks) |
| |
| if try_block.continue_from: |
| if env.PYBEHAVIOR.finally_jumps_back: |
| for continue_line in try_block.continue_from: |
| lineno = continue_line.lineno |
| cause = continue_line.cause.format(lineno=lineno) |
| for final_exit in final_exits: |
| self.add_arc(final_exit.lineno, lineno, cause) |
| continues = try_block.continue_from |
| else: |
| continues = self._combine_finally_starts(try_block.continue_from, final_exits) |
| self.process_continue_exits(continues) |
| |
| if try_block.raise_from: |
| self.process_raise_exits( |
| self._combine_finally_starts(try_block.raise_from, final_exits), |
| ) |
| |
| if try_block.return_from: |
| if env.PYBEHAVIOR.finally_jumps_back: |
| for return_line in try_block.return_from: |
| lineno = return_line.lineno |
| cause = return_line.cause.format(lineno=lineno) |
| for final_exit in final_exits: |
| self.add_arc(final_exit.lineno, lineno, cause) |
| returns = try_block.return_from |
| else: |
| returns = self._combine_finally_starts(try_block.return_from, final_exits) |
| self.process_return_exits(returns) |
| |
| if exits: |
| # The finally clause's exits are only exits for the try block |
| # as a whole if the try block had some exits to begin with. |
| exits = final_exits |
| |
| return exits |
| |
| def _combine_finally_starts(self, starts: set[ArcStart], exits: set[ArcStart]) -> set[ArcStart]: |
| """Helper for building the cause of `finally` branches. |
| |
| "finally" clauses might not execute their exits, and the causes could |
| be due to a failure to execute any of the exits in the try block. So |
| we use the causes from `starts` as the causes for `exits`. |
| """ |
| causes = [] |
| for start in sorted(starts): |
| if start.cause: |
| causes.append(start.cause.format(lineno=start.lineno)) |
| cause = " or ".join(causes) |
| exits = {ArcStart(xit.lineno, cause) for xit in exits} |
| return exits |
| |
| def _handle__While(self, node: ast.While) -> set[ArcStart]: |
| start = to_top = self.line_for_node(node.test) |
| constant_test = self.is_constant_expr(node.test) |
| top_is_body0 = False |
| if constant_test: |
| top_is_body0 = True |
| if env.PYBEHAVIOR.keep_constant_test: |
| top_is_body0 = False |
| if top_is_body0: |
| to_top = self.line_for_node(node.body[0]) |
| self.block_stack.append(LoopBlock(start=to_top)) |
| from_start = ArcStart(start, cause="the condition on line {lineno} was never true") |
| exits = self.body_exits(node.body, from_start=from_start) |
| for xit in exits: |
| self.add_arc(xit.lineno, to_top, xit.cause) |
| exits = set() |
| my_block = self.block_stack.pop() |
| assert isinstance(my_block, LoopBlock) |
| exits.update(my_block.break_exits) |
| from_start = ArcStart(start, cause="the condition on line {lineno} was always true") |
| if node.orelse: |
| else_exits = self.body_exits(node.orelse, from_start=from_start) |
| exits |= else_exits |
| else: |
| # No `else` clause: you can exit from the start. |
| if not constant_test: |
| exits.add(from_start) |
| return exits |
| |
| def _handle__With(self, node: ast.With) -> set[ArcStart]: |
| start = self.line_for_node(node) |
| if env.PYBEHAVIOR.exit_through_with: |
| self.block_stack.append(WithBlock(start=start)) |
| exits = self.body_exits(node.body, from_start=ArcStart(start)) |
| if env.PYBEHAVIOR.exit_through_with: |
| with_block = self.block_stack.pop() |
| assert isinstance(with_block, WithBlock) |
| with_exit = {ArcStart(start)} |
| if exits: |
| for xit in exits: |
| self.add_arc(xit.lineno, start) |
| exits = with_exit |
| if with_block.break_from: |
| self.process_break_exits( |
| self._combine_finally_starts(with_block.break_from, with_exit), |
| ) |
| if with_block.continue_from: |
| self.process_continue_exits( |
| self._combine_finally_starts(with_block.continue_from, with_exit), |
| ) |
| if with_block.return_from: |
| self.process_return_exits( |
| self._combine_finally_starts(with_block.return_from, with_exit), |
| ) |
| return exits |
| |
| _handle__AsyncWith = _handle__With |
