## Summary
Removes the `module_ptr` field from `AstNodeRef` in release mode, and
change `NodeIndex` to a `NonZeroU32` to reduce the size of
`Option<AstNodeRef<_>>` fields.
I believe CI runs in debug mode, so this won't show up in the memory
report, but this reduces memory by ~2% in release mode.
As of [this cpython PR](https://github.com/python/cpython/pull/135996),
it is not allowed to concatenate t-strings with non-t-strings,
implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now
syntax errors.
This PR updates some AST nodes and parsing to reflect this change.
The structural change is that `TStringPart` is no longer needed, since,
as in the case of `BytesStringLiteral`, the only possibilities are that
we have a single `TString` or a vector of such (representing an implicit
concatenation of t-strings). This removes a level of nesting from many
AST expressions (which is what all the snapshot changes reflect), and
simplifies some logic in the implementation of visitors, for example.
The other change of note is in the parser. When we meet an implicit
concatenation of string-like literals, we now count the number of
t-string literals. If these do not exhaust the total number of
implicitly concatenated pieces, then we emit a syntax error. To recover
from this syntax error, we encode any t-string pieces as _invalid_
string literals (which means we flag them as invalid, record their
range, and record the value as `""`). Note that if at least one of the
pieces is an f-string we prefer to parse the entire string as an
f-string; otherwise we parse it as a string.
This logic is exactly the same as how we currently treat
`BytesStringLiteral` parsing and error recovery - and carries with it
the same pros and cons.
Finally, note that I have not implemented any changes in the
implementation of the formatter. As far as I can tell, none are needed.
I did change a few of the fixtures so that we are always concatenating
t-strings with t-strings.
## Summary
Garbage collect ASTs once we are done checking a given file. Queries
with a cross-file dependency on the AST will reparse the file on demand.
This reduces ty's peak memory usage by ~20-30%.
The primary change of this PR is adding a `node_index` field to every
AST node, that is assigned by the parser. `ParsedModule` can use this to
create a flat index of AST nodes any time the file is parsed (or
reparsed). This allows `AstNodeRef` to simply index into the current
instance of the `ParsedModule`, instead of storing a pointer directly.
The indices are somewhat hackily (using an atomic integer) assigned by
the `parsed_module` query instead of by the parser directly. Assigning
the indices in source-order in the (recursive) parser turns out to be
difficult, and collecting the nodes during semantic indexing is
impossible as `SemanticIndex` does not hold onto a specific
`ParsedModuleRef`, which the pointers in the flat AST are tied to. This
means that we have to do an extra AST traversal to assign and collect
the nodes into a flat index, but the small performance impact (~3% on
cold runs) seems worth it for the memory savings.
Part of https://github.com/astral-sh/ty/issues/214.
This PR implements template strings (t-strings) in the parser and
formatter for Ruff.
Minimal changes necessary to compile were made in other parts of the code (e.g. ty, the linter, etc.). These will be covered properly in follow-up PRs.
Summary
--
Detects duplicate type parameter names in function definitions, class
definitions, and type alias statements.
I also boxed the `type_params` field on `StmtTypeAlias` to make it
easier to
`match` with functions and classes. (That's the reason for the red-knot
code
owner review requests, sorry!)
Test Plan
--
New `ruff_python_syntax_errors` unit tests.
Fixes#11119.
When suggesting a return type as a union in Python <=3.9, we now avoid a
`TypeError` by correctly suggesting syntax like `Union[int,str,None]`
instead of `Union[int | str | None]`.
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## Summary
Treat async generators as "await" in ASYNC100.
Fixes#13637
## Test Plan
Updated snapshot
(Supersedes #9152, authored by @LaBatata101)
## Summary
This PR replaces the current parser generated from LALRPOP to a
hand-written recursive descent parser.
It also updates the grammar for [PEP
646](https://peps.python.org/pep-0646/) so that the parser outputs the
correct AST. For example, in `data[*x]`, the index expression is now a
tuple with a single starred expression instead of just a starred
expression.
Beyond the performance improvements, the parser is also error resilient
and can provide better error messages. The behavior as seen by any
downstream tools isn't changed. That is, the linter and formatter can
still assume that the parser will _stop_ at the first syntax error. This
will be updated in the following months.
For more details about the change here, refer to the PR corresponding to
the individual commits and the release blog post.
## Test Plan
Write _lots_ and _lots_ of tests for both valid and invalid syntax and
verify the output.
## Acknowledgements
- @MichaReiser for reviewing 100+ parser PRs and continuously providing
guidance throughout the project
- @LaBatata101 for initiating the transition to a hand-written parser in
#9152
- @addisoncrump for implementing the fuzzer which helped
[catch](https://github.com/astral-sh/ruff/pull/10903)
[a](https://github.com/astral-sh/ruff/pull/10910)
[lot](https://github.com/astral-sh/ruff/pull/10966)
[of](https://github.com/astral-sh/ruff/pull/10896)
[bugs](https://github.com/astral-sh/ruff/pull/10877)
---------
Co-authored-by: Victor Hugo Gomes <labatata101@linuxmail.org>
Co-authored-by: Micha Reiser <micha@reiser.io>
The expression types in our AST are called `ExprYield`, `ExprAwait`,
`ExprStringLiteral` etc, except `ExprNamedExpr`, `ExprIfExpr` and
`ExprGenratorExpr`. This seems to align with [Python AST's
naming](https://docs.python.org/3/library/ast.html) but feels
inconsistent and excessive.
This PR removes the `Expr` postfix from `ExprNamedExpr`, `ExprIfExpr`,
and `ExprGeneratorExpr`.
## Summary
Charlie can probably explain this better than I but it turns out,
`CallPath` is used for two different things:
* To represent unqualified names like `version` where `version` can be a
local variable or imported (e.g. `from sys import version` where the
full qualified name is `sys.version`)
* To represent resolved, full qualified names
This PR splits `CallPath` into two types to make this destinction clear.
> Note: I haven't renamed all `call_path` variables to `qualified_name`
or `unqualified_name`. I can do that if that's welcomed but I first want
to get feedback on the approach and naming overall.
## Test Plan
`cargo test`
## Summary
This PR removes the unneeded lifetime `'b` from many of our `Visitor`
implementations.
The lifetime is unneeded because it is only constraint by `'a`, so we
can use `'a` directly.
## Test Plan
`cargo build`
## Summary
This PR changes the `CallPath` type alias to a newtype wrapper.
A newtype wrapper allows us to limit the API and to experiment with
alternative ways to implement matching on `CallPath`s.
## Test Plan
`cargo test`
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Fixes#6611
## Summary
This lint rule spots comments that are _intended_ to suppress or enable
the formatter, but will be ignored by the Ruff formatter.
We borrow some functions the formatter uses for determining comment
placement / putting them in context within an AST.
The analysis function uses an AST visitor to visit each comment and
attach it to the AST. It then uses that context to check:
1. Is this comment in an expression?
2. Does this comment have bad placement? (e.g. a `# fmt: skip` above a
function instead of at the end of a line)
3. Is this comment redundant?
4. Does this comment actually suppress any code?
5. Does this comment have ambiguous placement? (e.g. a `# fmt: off`
above an `else:` block)
If any of these are true, a violation is thrown. The reported reason
depends on the order of the above check-list: in other words, a `# fmt:
skip` comment on its own line within a list expression will be reported
as being in an expression, since that reason takes priority.
The lint suggests removing the comment as an unsafe fix, regardless of
the reason.
## Test Plan
A snapshot test has been created.
## Summary
This PR ensures that if a list `x` is modified within a `for` loop, we
avoid flagging `list(x)` as unnecessary. Previously, we only detected
calls to exactly `.append`, and they couldn't be nested within other
statements.
Closes https://github.com/astral-sh/ruff/issues/9925.
## Summary
This PR reduces the size of `Expr` from 80 to 64 bytes, by reducing the
sizes of...
- `ExprCall` from 72 to 56 bytes, by using boxed slices for `Arguments`.
- `ExprCompare` from 64 to 48 bytes, by using boxed slices for its
various vectors.
In testing, the parser gets a bit faster, and the linter benchmarks
improve quite a bit.
## Summary
Given:
```python
from somewhere import get_cfg
def lookup_cfg(cfg_description):
cfg = get_cfg(cfg_description)
if cfg is not None:
return cfg
raise AttributeError(f"No cfg found matching {cfg_description}")
```
We were analyzing the method from last-to-first statement. So we saw the
`raise`, then assumed the method _always_ raised. In reality, though, it
_might_ return. This PR improves the branch analysis to respect these
mixed cases.
Closes https://github.com/astral-sh/ruff/issues/9269.
Closes https://github.com/astral-sh/ruff/issues/9304.
## Summary
Adds a rule to detect unions that include `typing.NoReturn` or
`typing.Never`. In such cases, the use of the bottom type is redundant.
Closes https://github.com/astral-sh/ruff/issues/9113.
## Test Plan
`cargo test`
## Summary
Given a function like:
```python
def func(x: int):
if not x:
raise ValueError
else:
raise TypeError
```
We now correctly use `NoReturn` as the return type, rather than `None`.
Closes https://github.com/astral-sh/ruff/issues/9201.
This PR adds a `as_slice` method to all the string nodes which returns
all the parts of the nodes as a slice. This will be useful in the next
PR to split the string formatting to use this method to extract the
_single node_ or _implicitly concanated nodes_.
Rebase of #6365 authored by @davidszotten.
## Summary
This PR updates the AST structure for an f-string elements.
The main **motivation** behind this change is to have a dedicated node
for the string part of an f-string. Previously, the existing
`ExprStringLiteral` node was used for this purpose which isn't exactly
correct. The `ExprStringLiteral` node should include the quotes as well
in the range but the f-string literal element doesn't include the quote
as it's a specific part within an f-string. For example,
```python
f"foo {x}"
# ^^^^
# This is the literal part of an f-string
```
The introduction of `FStringElement` enum is helpful which represent
either the literal part or the expression part of an f-string.
### Rule Updates
This means that there'll be two nodes representing a string depending on
the context. One for a normal string literal while the other is a string
literal within an f-string. The AST checker is updated to accommodate
this change. The rules which work on string literal are updated to check
on the literal part of f-string as well.
#### Notes
1. The `Expr::is_literal_expr` method would check for
`ExprStringLiteral` and return true if so. But now that we don't
represent the literal part of an f-string using that node, this improves
the method's behavior and confines to the actual expression. We do have
the `FStringElement::is_literal` method.
2. We avoid checking if we're in a f-string context before adding to
`string_type_definitions` because the f-string literal is now a
dedicated node and not part of `Expr`.
3. Annotations cannot use f-string so we avoid changing any rules which
work on annotation and checks for `ExprStringLiteral`.
## Test Plan
- All references of `Expr::StringLiteral` were checked to see if any of
the rules require updating to account for the f-string literal element
node.
- New test cases are added for rules which check against the literal
part of an f-string.
- Check the ecosystem results and ensure it remains unchanged.
## Performance
There's a performance penalty in the parser. The reason for this remains
unknown as it seems that the generated assembly code is now different
for the `__reduce154` function. The reduce function body is just popping
the `ParenthesizedExpr` on top of the stack and pushing it with the new
location.
- The size of `FStringElement` enum is the same as `Expr` which is what
it replaces in `FString::format_spec`
- The size of `FStringExpressionElement` is the same as
`ExprFormattedValue` which is what it replaces
I tried reducing the `Expr` enum from 80 bytes to 72 bytes but it hardly
resulted in any performance gain. The difference can be seen here:
- Original profile: https://share.firefox.dev/3Taa7ES
- Profile after boxing some node fields:
https://share.firefox.dev/3GsNXpD
### Backtracking
I tried backtracking the changes to see if any of the isolated change
produced this regression. The problem here is that the overall change is
so small that there's only a single checkpoint where I can backtrack and
that checkpoint results in the same regression. This checkpoint is to
revert using `Expr` to the `FString::format_spec` field. After this
point, the change would revert back to the original implementation.
## Review process
The review process is similar to #7927. The first set of commits update
the node structure, parser, and related AST files. Then, further commits
update the linter and formatter part to account for the AST change.
---------
Co-authored-by: David Szotten <davidszotten@gmail.com>
## Summary
Adds detection for branches without a `return` or `raise`, so that we
can properly `Optional` the return types. I'd like to remove this and
replace it with our code graph analysis from the `unreachable.rs` rule,
but it at least fixes the worst offenders.
Closes#8942.
## Summary
This PR updates the string nodes (`ExprStringLiteral`,
`ExprBytesLiteral`, and `ExprFString`) to account for implicit string
concatenation.
### Motivation
In Python, implicit string concatenation are joined while parsing
because the interpreter doesn't require the information for each part.
While that's feasible for an interpreter, it falls short for a static
analysis tool where having such information is more useful. Currently,
various parts of the code uses the lexer to get the individual string
parts.
One of the main challenge this solves is that of string formatting.
Currently, the formatter relies on the lexer to get the individual
string parts, and formats them including the comments accordingly. But,
with PEP 701, f-string can also contain comments. Without this change,
it becomes very difficult to add support for f-string formatting.
### Implementation
The initial proposal was made in this discussion:
https://github.com/astral-sh/ruff/discussions/6183#discussioncomment-6591993.
There were various AST designs which were explored for this task which
are available in the linked internal document[^1].
The selected variant was the one where the nodes were kept as it is
except that the `implicit_concatenated` field was removed and instead a
new struct was added to the `Expr*` struct. This would be a private
struct would contain the actual implementation of how the AST is
designed for both single and implicitly concatenated strings.
This implementation is achieved through an enum with two variants:
`Single` and `Concatenated` to avoid allocating a vector even for single
strings. There are various public methods available on the value struct
to query certain information regarding the node.
The nodes are structured in the following way:
```
ExprStringLiteral - "foo" "bar"
|- StringLiteral - "foo"
|- StringLiteral - "bar"
ExprBytesLiteral - b"foo" b"bar"
|- BytesLiteral - b"foo"
|- BytesLiteral - b"bar"
ExprFString - "foo" f"bar {x}"
|- FStringPart::Literal - "foo"
|- FStringPart::FString - f"bar {x}"
|- StringLiteral - "bar "
|- FormattedValue - "x"
```
[^1]: Internal document:
https://www.notion.so/astral-sh/Implicit-String-Concatenation-e036345dc48943f89e416c087bf6f6d9?pvs=4
#### Visitor
The way the nodes are structured is that the entire string, including
all the parts that are implicitly concatenation, is a single node
containing individual nodes for the parts. The previous section has a
representation of that tree for all the string nodes. This means that
new visitor methods are added to visit the individual parts of string,
bytes, and f-strings for `Visitor`, `PreorderVisitor`, and
`Transformer`.
## Test Plan
- `cargo insta test --workspace --all-features --unreferenced reject`
- Verify that the ecosystem results are unchanged
## Summary
This PR adds (unsafe) fixes to the flake8-annotations rules that enforce
missing return types, offering to automatically insert type annotations
for functions with literal return values. The logic is smart enough to
generate simplified unions (e.g., `float` instead of `int | float`) and
deal with implicit returns (`return` without a value).
Closes https://github.com/astral-sh/ruff/issues/1640 (though we could
open a separate issue for referring parameter types).
Closes https://github.com/astral-sh/ruff/issues/8213.
## Test Plan
`cargo test`
## Summary
Adds an extra check to F632 to check for any `is` comparisons to a
mutable initialisers.
Implements #8589 .
Example:
```Python
named_var = {}
if named_var is {}: # F632 (fix)
pass
```
The if condition will always evaluate to False because it checks on
identity and it's impossible to take the same identity as a hard coded
list/set/dict initializer.
## Test Plan
Multiple test cases were added to ensure the rule works + doesn't flag
false positives + the fix works correctly.
## Summary
Adds `TRIO105` from the [flake8-trio
plugin](https://github.com/Zac-HD/flake8-trio). The `MethodName` logic
mirrors that of `TRIO100` to stay consistent within the plugin.
It is at 95% parity with the exception of upstream also checking for a
slightly more complex scenario where a call to `start()` on a
`trio.Nursery` context should also be immediately awaited. Upstream
plugin appears to just check for anything named `nursery` judging from
[the relevant issue](https://github.com/Zac-HD/flake8-trio/issues/56).
Unsure if we want to do so something similar or, alternatively, if there
is some capability in ruff to check for calls made on this context some
other way
## Test Plan
Added a new fixture, based on [the one from upstream
plugin](https://github.com/Zac-HD/flake8-trio/blob/main/tests/eval_files/trio105.py)
## Issue link
Refers: https://github.com/astral-sh/ruff/issues/8451
