ruff/crates/ruff_python_parser/src/error.rs

715 lines
26 KiB
Rust

use std::fmt::{self, Display};
use ruff_python_ast::PythonVersion;
use ruff_text_size::{Ranged, TextRange};
use crate::TokenKind;
/// Represents represent errors that occur during parsing and are
/// returned by the `parse_*` functions.
#[derive(Debug, PartialEq, Clone)]
pub struct ParseError {
pub error: ParseErrorType,
pub location: TextRange,
}
impl std::ops::Deref for ParseError {
type Target = ParseErrorType;
fn deref(&self) -> &Self::Target {
&self.error
}
}
impl std::error::Error for ParseError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
Some(&self.error)
}
}
impl fmt::Display for ParseError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(f, "{} at byte range {:?}", &self.error, self.location)
}
}
impl From<LexicalError> for ParseError {
fn from(error: LexicalError) -> Self {
ParseError {
location: error.location(),
error: ParseErrorType::Lexical(error.into_error()),
}
}
}
impl ParseError {
pub fn error(self) -> ParseErrorType {
self.error
}
}
/// Represents the different types of errors that can occur during parsing of an f-string.
#[derive(Debug, Clone, PartialEq)]
pub enum FStringErrorType {
/// Expected a right brace after an opened left brace.
UnclosedLbrace,
/// An invalid conversion flag was encountered.
InvalidConversionFlag,
/// A single right brace was encountered.
SingleRbrace,
/// Unterminated string.
UnterminatedString,
/// Unterminated triple-quoted string.
UnterminatedTripleQuotedString,
/// A lambda expression without parentheses was encountered.
LambdaWithoutParentheses,
}
impl std::fmt::Display for FStringErrorType {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
use FStringErrorType::{
InvalidConversionFlag, LambdaWithoutParentheses, SingleRbrace, UnclosedLbrace,
UnterminatedString, UnterminatedTripleQuotedString,
};
match self {
UnclosedLbrace => write!(f, "expecting '}}'"),
InvalidConversionFlag => write!(f, "invalid conversion character"),
SingleRbrace => write!(f, "single '}}' is not allowed"),
UnterminatedString => write!(f, "unterminated string"),
UnterminatedTripleQuotedString => write!(f, "unterminated triple-quoted string"),
LambdaWithoutParentheses => {
write!(f, "lambda expressions are not allowed without parentheses")
}
}
}
}
/// Represents the different types of errors that can occur during parsing.
#[derive(Debug, PartialEq, Clone)]
pub enum ParseErrorType {
/// An unexpected error occurred.
OtherError(String),
/// An empty slice was found during parsing, e.g `data[]`.
EmptySlice,
/// An empty global names list was found during parsing.
EmptyGlobalNames,
/// An empty nonlocal names list was found during parsing.
EmptyNonlocalNames,
/// An empty delete targets list was found during parsing.
EmptyDeleteTargets,
/// An empty import names list was found during parsing.
EmptyImportNames,
/// An empty type parameter list was found during parsing.
EmptyTypeParams,
/// An unparenthesized named expression was found where it is not allowed.
UnparenthesizedNamedExpression,
/// An unparenthesized tuple expression was found where it is not allowed.
UnparenthesizedTupleExpression,
/// An unparenthesized generator expression was found where it is not allowed.
UnparenthesizedGeneratorExpression,
/// An invalid usage of a lambda expression was found.
InvalidLambdaExpressionUsage,
/// An invalid usage of a yield expression was found.
InvalidYieldExpressionUsage,
/// An invalid usage of a starred expression was found.
InvalidStarredExpressionUsage,
/// A star pattern was found outside a sequence pattern.
InvalidStarPatternUsage,
/// A parameter was found after a vararg.
ParamAfterVarKeywordParam,
/// A non-default parameter follows a default parameter.
NonDefaultParamAfterDefaultParam,
/// A default value was found for a `*` or `**` parameter.
VarParameterWithDefault,
/// A duplicate parameter was found in a function definition or lambda expression.
DuplicateParameter(String),
/// A keyword argument was repeated.
DuplicateKeywordArgumentError(String),
/// An invalid expression was found in the assignment target.
InvalidAssignmentTarget,
/// An invalid expression was found in the named assignment target.
InvalidNamedAssignmentTarget,
/// An invalid expression was found in the annotated assignment target.
InvalidAnnotatedAssignmentTarget,
/// An invalid expression was found in the augmented assignment target.
InvalidAugmentedAssignmentTarget,
/// An invalid expression was found in the delete target.
InvalidDeleteTarget,
/// A positional argument was found after a keyword argument.
PositionalAfterKeywordArgument,
/// A positional argument was found after a keyword argument unpacking.
PositionalAfterKeywordUnpacking,
/// An iterable argument unpacking was found after keyword argument unpacking.
InvalidArgumentUnpackingOrder,
/// An invalid usage of iterable unpacking in a comprehension was found.
IterableUnpackingInComprehension,
/// Multiple simple statements were found in the same line without a `;` separating them.
SimpleStatementsOnSameLine,
/// A simple statement and a compound statement was found in the same line.
SimpleAndCompoundStatementOnSameLine,
/// Expected one or more keyword parameter after `*` separator.
ExpectedKeywordParam,
/// Expected a real number for a complex literal pattern.
ExpectedRealNumber,
/// Expected an imaginary number for a complex literal pattern.
ExpectedImaginaryNumber,
/// Expected an expression at the current parser location.
ExpectedExpression,
/// The parser expected a specific token that was not found.
ExpectedToken {
expected: TokenKind,
found: TokenKind,
},
/// An unexpected indentation was found during parsing.
UnexpectedIndentation,
/// The statement being parsed cannot be `async`.
UnexpectedTokenAfterAsync(TokenKind),
/// Ipython escape command was found
UnexpectedIpythonEscapeCommand,
/// An unexpected token was found at the end of an expression parsing
UnexpectedExpressionToken,
/// An f-string error containing the [`FStringErrorType`].
FStringError(FStringErrorType),
/// Parser encountered an error during lexing.
Lexical(LexicalErrorType),
}
impl std::error::Error for ParseErrorType {}
impl std::fmt::Display for ParseErrorType {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
ParseErrorType::OtherError(msg) => write!(f, "{msg}"),
ParseErrorType::ExpectedToken { found, expected } => {
write!(f, "Expected {expected}, found {found}",)
}
ParseErrorType::Lexical(ref lex_error) => write!(f, "{lex_error}"),
ParseErrorType::SimpleStatementsOnSameLine => {
f.write_str("Simple statements must be separated by newlines or semicolons")
}
ParseErrorType::SimpleAndCompoundStatementOnSameLine => f.write_str(
"Compound statements are not allowed on the same line as simple statements",
),
ParseErrorType::UnexpectedTokenAfterAsync(kind) => {
write!(
f,
"Expected 'def', 'with' or 'for' to follow 'async', found {kind}",
)
}
ParseErrorType::InvalidArgumentUnpackingOrder => {
f.write_str("Iterable argument unpacking cannot follow keyword argument unpacking")
}
ParseErrorType::IterableUnpackingInComprehension => {
f.write_str("Iterable unpacking cannot be used in a comprehension")
}
ParseErrorType::UnparenthesizedNamedExpression => {
f.write_str("Unparenthesized named expression cannot be used here")
}
ParseErrorType::UnparenthesizedTupleExpression => {
f.write_str("Unparenthesized tuple expression cannot be used here")
}
ParseErrorType::UnparenthesizedGeneratorExpression => {
f.write_str("Unparenthesized generator expression cannot be used here")
}
ParseErrorType::InvalidYieldExpressionUsage => {
f.write_str("Yield expression cannot be used here")
}
ParseErrorType::InvalidLambdaExpressionUsage => {
f.write_str("Lambda expression cannot be used here")
}
ParseErrorType::InvalidStarredExpressionUsage => {
f.write_str("Starred expression cannot be used here")
}
ParseErrorType::PositionalAfterKeywordArgument => {
f.write_str("Positional argument cannot follow keyword argument")
}
ParseErrorType::PositionalAfterKeywordUnpacking => {
f.write_str("Positional argument cannot follow keyword argument unpacking")
}
ParseErrorType::EmptySlice => f.write_str("Expected index or slice expression"),
ParseErrorType::EmptyGlobalNames => {
f.write_str("Global statement must have at least one name")
}
ParseErrorType::EmptyNonlocalNames => {
f.write_str("Nonlocal statement must have at least one name")
}
ParseErrorType::EmptyDeleteTargets => {
f.write_str("Delete statement must have at least one target")
}
ParseErrorType::EmptyImportNames => {
f.write_str("Expected one or more symbol names after import")
}
ParseErrorType::EmptyTypeParams => f.write_str("Type parameter list cannot be empty"),
ParseErrorType::ParamAfterVarKeywordParam => {
f.write_str("Parameter cannot follow var-keyword parameter")
}
ParseErrorType::NonDefaultParamAfterDefaultParam => {
f.write_str("Parameter without a default cannot follow a parameter with a default")
}
ParseErrorType::ExpectedKeywordParam => {
f.write_str("Expected one or more keyword parameter after '*' separator")
}
ParseErrorType::VarParameterWithDefault => {
f.write_str("Parameter with '*' or '**' cannot have default value")
}
ParseErrorType::InvalidStarPatternUsage => {
f.write_str("Star pattern cannot be used here")
}
ParseErrorType::ExpectedRealNumber => {
f.write_str("Expected a real number in complex literal pattern")
}
ParseErrorType::ExpectedImaginaryNumber => {
f.write_str("Expected an imaginary number in complex literal pattern")
}
ParseErrorType::ExpectedExpression => f.write_str("Expected an expression"),
ParseErrorType::UnexpectedIndentation => f.write_str("Unexpected indentation"),
ParseErrorType::InvalidAssignmentTarget => f.write_str("Invalid assignment target"),
ParseErrorType::InvalidAnnotatedAssignmentTarget => {
f.write_str("Invalid annotated assignment target")
}
ParseErrorType::InvalidNamedAssignmentTarget => {
f.write_str("Assignment expression target must be an identifier")
}
ParseErrorType::InvalidAugmentedAssignmentTarget => {
f.write_str("Invalid augmented assignment target")
}
ParseErrorType::InvalidDeleteTarget => f.write_str("Invalid delete target"),
ParseErrorType::DuplicateParameter(arg_name) => {
write!(f, "Duplicate parameter {arg_name:?}")
}
ParseErrorType::DuplicateKeywordArgumentError(arg_name) => {
write!(f, "Duplicate keyword argument {arg_name:?}")
}
ParseErrorType::UnexpectedIpythonEscapeCommand => {
f.write_str("IPython escape commands are only allowed in `Mode::Ipython`")
}
ParseErrorType::FStringError(ref fstring_error) => {
write!(f, "f-string: {fstring_error}")
}
ParseErrorType::UnexpectedExpressionToken => {
write!(f, "Unexpected token at the end of an expression")
}
}
}
}
/// Represents an error that occur during lexing and are
/// returned by the `parse_*` functions in the iterator in the
/// [lexer] implementation.
///
/// [lexer]: crate::lexer
#[derive(Debug, Clone, PartialEq)]
pub struct LexicalError {
/// The type of error that occurred.
error: LexicalErrorType,
/// The location of the error.
location: TextRange,
}
impl LexicalError {
/// Creates a new `LexicalError` with the given error type and location.
pub fn new(error: LexicalErrorType, location: TextRange) -> Self {
Self { error, location }
}
pub fn error(&self) -> &LexicalErrorType {
&self.error
}
pub fn into_error(self) -> LexicalErrorType {
self.error
}
pub fn location(&self) -> TextRange {
self.location
}
}
impl std::ops::Deref for LexicalError {
type Target = LexicalErrorType;
fn deref(&self) -> &Self::Target {
self.error()
}
}
impl std::error::Error for LexicalError {
fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
Some(self.error())
}
}
impl std::fmt::Display for LexicalError {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
write!(
f,
"{} at byte offset {}",
self.error(),
u32::from(self.location().start())
)
}
}
/// Represents the different types of errors that can occur during lexing.
#[derive(Debug, Clone, PartialEq)]
pub enum LexicalErrorType {
// TODO: Can probably be removed, the places it is used seem to be able
// to use the `UnicodeError` variant instead.
#[doc(hidden)]
StringError,
/// A string literal without the closing quote.
UnclosedStringError,
/// Decoding of a unicode escape sequence in a string literal failed.
UnicodeError,
/// Missing the `{` for unicode escape sequence.
MissingUnicodeLbrace,
/// Missing the `}` for unicode escape sequence.
MissingUnicodeRbrace,
/// The indentation is not consistent.
IndentationError,
/// An unrecognized token was encountered.
UnrecognizedToken { tok: char },
/// An f-string error containing the [`FStringErrorType`].
FStringError(FStringErrorType),
/// Invalid character encountered in a byte literal.
InvalidByteLiteral,
/// An unexpected character was encountered after a line continuation.
LineContinuationError,
/// An unexpected end of file was encountered.
Eof,
/// An unexpected error occurred.
OtherError(Box<str>),
}
impl std::error::Error for LexicalErrorType {}
impl std::fmt::Display for LexicalErrorType {
fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
match self {
LexicalErrorType::StringError => write!(f, "Got unexpected string"),
LexicalErrorType::FStringError(error) => write!(f, "f-string: {error}"),
LexicalErrorType::InvalidByteLiteral => {
write!(f, "bytes can only contain ASCII literal characters")
}
LexicalErrorType::UnicodeError => write!(f, "Got unexpected unicode"),
LexicalErrorType::IndentationError => {
write!(f, "unindent does not match any outer indentation level")
}
LexicalErrorType::UnrecognizedToken { tok } => {
write!(f, "Got unexpected token {tok}")
}
LexicalErrorType::LineContinuationError => {
write!(f, "Expected a newline after line continuation character")
}
LexicalErrorType::Eof => write!(f, "unexpected EOF while parsing"),
LexicalErrorType::OtherError(msg) => write!(f, "{msg}"),
LexicalErrorType::UnclosedStringError => {
write!(f, "missing closing quote in string literal")
}
LexicalErrorType::MissingUnicodeLbrace => {
write!(f, "Missing `{{` in Unicode escape sequence")
}
LexicalErrorType::MissingUnicodeRbrace => {
write!(f, "Missing `}}` in Unicode escape sequence")
}
}
}
}
/// Represents a version-related syntax error detected during parsing.
///
/// An example of a version-related error is the use of a `match` statement before Python 3.10, when
/// it was first introduced. See [`UnsupportedSyntaxErrorKind`] for other kinds of errors.
#[derive(Debug, PartialEq, Clone)]
pub struct UnsupportedSyntaxError {
pub kind: UnsupportedSyntaxErrorKind,
pub range: TextRange,
/// The target [`PythonVersion`] for which this error was detected.
pub target_version: PythonVersion,
}
impl Ranged for UnsupportedSyntaxError {
fn range(&self) -> TextRange {
self.range
}
}
/// The type of tuple unpacking for [`UnsupportedSyntaxErrorKind::StarTuple`].
#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
pub enum StarTupleKind {
Return,
Yield,
}
#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy)]
pub enum UnsupportedSyntaxErrorKind {
Match,
Walrus,
ExceptStar,
/// Represents the use of a parenthesized keyword argument name after Python 3.8.
///
/// ## Example
///
/// From [BPO 34641] it sounds like this was only accidentally supported and was removed when
/// noticed. Code like this used to be valid:
///
/// ```python
/// f((a)=1)
/// ```
///
/// After Python 3.8, you have to omit the parentheses around `a`:
///
/// ```python
/// f(a=1)
/// ```
///
/// [BPO 34641]: https://github.com/python/cpython/issues/78822
ParenthesizedKeywordArgumentName,
/// Represents the use of unparenthesized tuple unpacking in a `return` statement or `yield`
/// expression before Python 3.8.
///
/// ## Examples
///
/// Before Python 3.8, this syntax was allowed:
///
/// ```python
/// rest = (4, 5, 6)
///
/// def f():
/// t = 1, 2, 3, *rest
/// return t
///
/// def g():
/// t = 1, 2, 3, *rest
/// yield t
/// ```
///
/// But this was not:
///
/// ```python
/// rest = (4, 5, 6)
///
/// def f():
/// return 1, 2, 3, *rest
///
/// def g():
/// yield 1, 2, 3, *rest
/// ```
///
/// Instead, parentheses were required in the `return` and `yield` cases:
///
/// ```python
/// rest = (4, 5, 6)
///
/// def f():
/// return (1, 2, 3, *rest)
///
/// def g():
/// yield (1, 2, 3, *rest)
/// ```
///
/// This was reported in [BPO 32117] and updated in Python 3.8 to allow the unparenthesized
/// form.
///
/// [BPO 32117]: https://github.com/python/cpython/issues/76298
StarTuple(StarTupleKind),
/// Represents the use of a "relaxed" [PEP 614] decorator before Python 3.9.
///
/// ## Examples
///
/// Prior to Python 3.9, decorators were defined to be [`dotted_name`]s, optionally followed by
/// an argument list. For example:
///
/// ```python
/// @buttons.clicked.connect
/// def foo(): ...
///
/// @buttons.clicked.connect(1, 2, 3)
/// def foo(): ...
/// ```
///
/// As pointed out in the PEP, this prevented reasonable extensions like subscripts:
///
/// ```python
/// buttons = [QPushButton(f'Button {i}') for i in range(10)]
///
/// @buttons[0].clicked.connect
/// def spam(): ...
/// ```
///
/// Python 3.9 removed these restrictions and expanded the [decorator grammar] to include any
/// assignment expression and include cases like the example above.
///
/// [PEP 614]: https://peps.python.org/pep-0614/
/// [`dotted_name`]: https://docs.python.org/3.8/reference/compound_stmts.html#grammar-token-dotted-name
/// [decorator grammar]: https://docs.python.org/3/reference/compound_stmts.html#grammar-token-python-grammar-decorator
RelaxedDecorator,
/// Represents the use of a [PEP 570] positional-only parameter before Python 3.8.
///
/// ## Examples
///
/// Python 3.8 added the `/` syntax for marking preceding parameters as positional-only:
///
/// ```python
/// def foo(a, b, /, c): ...
/// ```
///
/// This means `a` and `b` in this case can only be provided by position, not by name. In other
/// words, this code results in a `TypeError` at runtime:
///
/// ```pycon
/// >>> def foo(a, b, /, c): ...
/// ...
/// >>> foo(a=1, b=2, c=3)
/// Traceback (most recent call last):
/// File "<python-input-3>", line 1, in <module>
/// foo(a=1, b=2, c=3)
/// ~~~^^^^^^^^^^^^^^^
/// TypeError: foo() got some positional-only arguments passed as keyword arguments: 'a, b'
/// ```
///
/// [PEP 570]: https://peps.python.org/pep-0570/
PositionalOnlyParameter,
/// Represents the use of a [type parameter list] before Python 3.12.
///
/// ## Examples
///
/// Before Python 3.12, generic parameters had to be declared separately using a class like
/// [`typing.TypeVar`], which could then be used in a function or class definition:
///
/// ```python
/// from typing import Generic, TypeVar
///
/// T = TypeVar("T")
///
/// def f(t: T): ...
/// class C(Generic[T]): ...
/// ```
///
/// [PEP 695], included in Python 3.12, introduced the new type parameter syntax, which allows
/// these to be written more compactly and without a separate type variable:
///
/// ```python
/// def f[T](t: T): ...
/// class C[T]: ...
/// ```
///
/// [type parameter list]: https://docs.python.org/3/reference/compound_stmts.html#type-parameter-lists
/// [PEP 695]: https://peps.python.org/pep-0695/
/// [`typing.TypeVar`]: https://docs.python.org/3/library/typing.html#typevar
TypeParameterList,
TypeAliasStatement,
TypeParamDefault,
}
impl Display for UnsupportedSyntaxError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let kind = match self.kind {
UnsupportedSyntaxErrorKind::Match => "Cannot use `match` statement",
UnsupportedSyntaxErrorKind::Walrus => "Cannot use named assignment expression (`:=`)",
UnsupportedSyntaxErrorKind::ExceptStar => "Cannot use `except*`",
UnsupportedSyntaxErrorKind::ParenthesizedKeywordArgumentName => {
"Cannot use parenthesized keyword argument name"
}
UnsupportedSyntaxErrorKind::StarTuple(StarTupleKind::Return) => {
"Cannot use iterable unpacking in return statements"
}
UnsupportedSyntaxErrorKind::StarTuple(StarTupleKind::Yield) => {
"Cannot use iterable unpacking in yield expressions"
}
UnsupportedSyntaxErrorKind::RelaxedDecorator => "Unsupported expression in decorators",
UnsupportedSyntaxErrorKind::PositionalOnlyParameter => {
"Cannot use positional-only parameter separator"
}
UnsupportedSyntaxErrorKind::TypeParameterList => "Cannot use type parameter lists",
UnsupportedSyntaxErrorKind::TypeAliasStatement => "Cannot use `type` alias statement",
UnsupportedSyntaxErrorKind::TypeParamDefault => {
"Cannot set default type for a type parameter"
}
};
write!(
f,
"{kind} on Python {} (syntax was {changed})",
self.target_version,
changed = self.kind.changed_version(),
)
}
}
/// Represents the kind of change in Python syntax between versions.
enum Change {
Added(PythonVersion),
Removed(PythonVersion),
}
impl Display for Change {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
Change::Added(version) => write!(f, "added in Python {version}"),
Change::Removed(version) => write!(f, "removed in Python {version}"),
}
}
}
impl UnsupportedSyntaxErrorKind {
/// Returns the Python version when the syntax associated with this error was changed, and the
/// type of [`Change`] (added or removed).
const fn changed_version(self) -> Change {
match self {
UnsupportedSyntaxErrorKind::Match => Change::Added(PythonVersion::PY310),
UnsupportedSyntaxErrorKind::Walrus => Change::Added(PythonVersion::PY38),
UnsupportedSyntaxErrorKind::ExceptStar => Change::Added(PythonVersion::PY311),
UnsupportedSyntaxErrorKind::StarTuple(_) => Change::Added(PythonVersion::PY38),
UnsupportedSyntaxErrorKind::RelaxedDecorator => Change::Added(PythonVersion::PY39),
UnsupportedSyntaxErrorKind::PositionalOnlyParameter => {
Change::Added(PythonVersion::PY38)
}
UnsupportedSyntaxErrorKind::ParenthesizedKeywordArgumentName => {
Change::Removed(PythonVersion::PY38)
}
UnsupportedSyntaxErrorKind::TypeParameterList => Change::Added(PythonVersion::PY312),
UnsupportedSyntaxErrorKind::TypeAliasStatement => Change::Added(PythonVersion::PY312),
UnsupportedSyntaxErrorKind::TypeParamDefault => Change::Added(PythonVersion::PY313),
}
}
/// Returns whether or not this kind of syntax is unsupported on `target_version`.
pub(crate) fn is_unsupported(self, target_version: PythonVersion) -> bool {
match self.changed_version() {
Change::Added(version) => target_version < version,
Change::Removed(version) => target_version >= version,
}
}
/// Returns `true` if this kind of syntax is supported on `target_version`.
pub(crate) fn is_supported(self, target_version: PythonVersion) -> bool {
!self.is_unsupported(target_version)
}
}
#[cfg(target_pointer_width = "64")]
mod sizes {
use crate::error::{LexicalError, LexicalErrorType};
use static_assertions::assert_eq_size;
assert_eq_size!(LexicalErrorType, [u8; 24]);
assert_eq_size!(LexicalError, [u8; 32]);
}