Crate clippy_utils

Type used to check whether two ast are the same. This is different from the operator == on ast types as this operator would compare true equality with ID and span.

SpanlessHash

Type used to hash an ast element. This is different from the Hash trait on ast types as this trait would consider IDs and spans.

Enums

CaptureKind

How a local is captured by a closure

Statics

BINOP_TRAITS

Binary operation traits like LangItem::Add

OP_ASSIGN_TRAITS

Operator-Assign traits like LangItem::AddAssign

TEST_ITEM_NAMES_CACHE 🔒

Functions

any_parent_has_attr

any_parent_is_automatically_derived

binop_traits

Converts BinOpKind::Add to (LangItem::Add, LangItem::AddAssign), for example

both

Checks if the two Options are both None or some equal values as per eq_fn.

can_move_expr_to_closure

Checks if the expression can be moved into a closure as is. This will return a list of captures if so, otherwise, None.

can_move_expr_to_closure_no_visit

Checks if the top level expression can be moved into a closure as is. Currently checks for:

can_mut_borrow_both

Checks if two expressions can be mutably borrowed simultaneously and they aren’t dependent on borrowing same thing twice

capture_local_usage

Given an expression referencing a local, determines how it would be captured in a closure. Note as this will walk up to parent expressions until the capture can be determined it should only be used while making a closure somewhere a value is consumed. e.g. a block, match arm, or function argument (other than a receiver).

clip

clip unused bytes

contains_name

Checks if an Expr contains a certain name.

contains_return

Returns true if expr contains a return expression

count_eq

Counts how many elements of the slices are equal as per eq_fn.

def_path_res

Resolves a def path like std::vec::Vec. This function is expensive and should be used sparingly.

eq_expr_value

Checks if two expressions evaluate to the same value, and don’t contain any side effects.

expr_custom_deref_adjustment

Gets the mutability of the custom deref adjustment, if any.

expr_or_init

If the given expression is a local binding, find the initializer expression. If that initializer expression is another local binding, find its initializer again. This process repeats as long as possible (but usually no more than once). Initializer expressions with adjustments are ignored. If this is not desired, use find_binding_init instead.

find_binding_init

Finds the initializer expression for a local binding. Returns None if the binding is mutable. By only considering immutable bindings, we guarantee that the returned expression represents the value of the binding wherever it is referenced.

fn_def_id

Returns the DefId of the callee if the given expression is a function or method call.

fn_has_unsatisfiable_preds

Check if it’s even possible to satisfy the where clause for the item.

get_async_fn_body

Peels away all the compiler generated code surrounding the body of an async function,

get_enclosing_block

get_enclosing_loop_or_multi_call_closure

Gets the loop or closure enclosing the given expression, if any.

get_expr_use_or_unification_node

Gets the node where an expression is either used, or it’s type is unified with another branch. Returns both the node and the HirId of the closest child node.

get_item_name

Gets the name of the item the expression is in, if available.

get_parent_as_impl

Gets the parent node if it’s an impl block.

get_parent_expr

Gets the parent expression, if any –- this is useful to constrain a lint.

get_parent_expr_for_hir

This retrieves the parent for the given HirId if it’s an expression. This is useful for constraint lints

get_parent_node

Gets the parent node, if any.

get_trait_def_id

Convenience function to get the DefId of a trait by path. It could be a trait or trait alias.

Returns the list of condition expressions and the list of blocks in a sequence of if/else. E.g., this returns ([a, b], [c, d, e]) for the expression if a { c } else if b { d } else { e }.

in_constant

Returns true if the given NodeId is inside a constant context

int_bits

is_adjusted

Returns true if the given Expr has been coerced before.

is_async_fn

Checks if the given function kind is an async function.

is_ctor_or_promotable_const_function

Checks if an expression is constructing a tuple-like enum variant or struct

is_default_equivalent

Returns true if the expr is equal to Default::default() of it’s type when evaluated. It doesn’t cover all cases, for example indirect function calls (some of std functions are supported) but it is the best we have.

is_default_equivalent_call

Return true if the expr is equal to Default::default when evaluated.

is_default_equivalent_ctor 🔒

Returns true if the def_id associated with the path is recognized as a “default-equivalent” constructor from the std library

is_diag_item_method

Checks if a method is defined in an impl of a diagnostic item

is_diag_trait_item

Checks if a method is in a diagnostic item trait

is_direct_expn_of

Returns the pre-expansion span if the span directly comes from an expansion of the macro name. The difference with is_expn_of is that in

is_else_clause

Checks if the given expression is the else clause of either an if or if let expression.

is_entrypoint_fn

Returns true if the provided def_id is an entrypoint to a program.

is_expn_of

Returns the pre-expansion span if this comes from an expansion of the macro name. See also is_direct_expn_of.

is_expr_final_block_expr

Checks if the expression is the final expression returned from a block.

is_expr_identity_function

Checks if an expression represents the identity function Only examines closures and std::convert::identity

is_expr_path_def_path

If the expression is a path, resolves it to a DefId and checks if it matches the given path.

is_expr_used_or_unified

Checks if the result of an expression is used, or it’s type is unified with another branch.

is_from_proc_macro

Checks if the item likely came from a proc-macro.

is_hir_ty_cfg_dependant

is_in_cfg_test

Checks if the item containing the given HirId has #[cfg(test)] attribute applied

is_in_panic_handler

Returns true if the expression is in the program’s #[panic_handler].

is_in_test_function

Checks if the function containing the given HirId is a #[test] function

is_integer_const

Checks whether the given expression is a constant integer of the given value. unlike is_integer_literal, this version does const folding

is_integer_literal

Checks whether the given expression is a constant literal of the given value.

is_lang_ctor

Checks if a QPath resolves to a constructor of a LangItem. For example, use this to check whether a function call or a pattern is Some(..).

is_lint_allowed

Returns true if the lint is allowed in the current context. This is useful for skipping long running code when it’s unnecessary

is_must_use_func_call

is_no_core_crate

is_no_std_crate

is_path_diagnostic_item

If maybe_path is a path node which resolves to an item, resolves it to a DefId and checks if it matches the given diagnostic item.

is_refutable

Returns true if a pattern is refutable.

is_self

is_self_ty

is_slice_of_primitives

Returns Option where String is a textual representation of the type encapsulated in the slice iff the given expression is a slice of primitives (as defined in the is_recursively_primitive_type function) and None otherwise.

is_span_if

Checks if the span actually refers to an if expression

is_span_match

Checks if the span actually refers to a match expression

is_test_module_or_function

Checks whether item either has test attribute applied, or is a module with test in its name.

is_trait_impl_item

Check if parent of a hir node is a trait implementation block. For example, f in

is_trait_item

Checks if the given expression is a path referring an item on the trait that is marked with the given diagnostic item.

is_trait_method

Checks if the method call given in expr belongs to the given trait.

is_try

Checks if a given expression is a match expression expanded from the ? operator or the try macro.

is_unit_expr

is_wild

Checks if given pattern is a wildcard (_)

iter_input_pats

last_path_segment

line_span 🔒

Extends the span to the beginning of the spans line, incl. whitespaces.

match_any_def_paths

Checks if the given DefId matches any of the paths. Returns the index of matching path, if any.

match_def_path

Checks if the given DefId matches the path.

match_function_call

Matches a function call with the given path and returns the arguments.

match_libc_symbol

Checks if the given DefId matches the libc item.

match_path

THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the entire path or resolved DefId. Prefer using match_def_path. Consider getting a DefId from QPath::Resolved.1.res.opt_def_id().

match_qpath

THIS METHOD IS DEPRECATED and will eventually be removed since it does not match against the entire path or resolved DefId. Prefer using match_def_path. Consider getting a DefId from QPath::Resolved.1.res.opt_def_id().

match_trait_method

Checks if the method call given in expr belongs to the given trait. This is a deprecated function, consider using is_trait_method.

meets_msrv

method_calls

Returns the method names and argument list of nested method call expressions that make up expr. method/span lists are sorted with the most recent call first.

method_chain_args

Matches an Expr against a chain of methods, and return the matched Exprs.

nth_arg

Convenience function to get the nth argument type of a function.

over

Checks if two slices are equal as per eq_fn.

parse_msrv

path_def_id

If maybe_path is a path node which resolves to an item, retrieves the item ID

path_res

If maybe_path is a path node, resolves it, otherwise returns Res::Err

path_to_local

If the expression is a path to a local, returns the canonical HirId of the local.

path_to_local_id

Returns true if the expression is a path to a local with the specified HirId. Use this function to see if an expression matches a function argument or a match binding.

peel_blocks

Removes blocks around an expression, only if the block contains just one expression and no statements. Unsafe blocks are not removed.

peel_blocks_with_stmt

Removes blocks around an expression, only if the block contains just one expression or just one expression statement with a semicolon. Unsafe blocks are not removed.

peel_hir_expr_refs

Peels off all references on the expression. Returns the underlying expression and the number of references removed.

peel_hir_expr_while

Peels of expressions while the given closure returns Some.

peel_hir_pat_refs

Peels off all references on the pattern. Returns the underlying pattern and the number of references removed.

peel_hir_ty_refs

Peels off all references on the type. Returns the underlying type and the number of references removed.

peel_n_hir_expr_refs

Peels off up to the given number of references on the expression. Returns the underlying expression and the number of references removed.

peel_ref_operators

Removes AddrOf operators (&) or deref operators (*), but only if a reference type is dereferenced. An overloaded deref such as Vec to slice would not be removed.

projection_stack 🔒

This method will return tuple of projection stack and root of the expression, used in can_mut_borrow_both.

qpath_generic_tys

recurse_or_patterns

If the pattern is an or pattern, call the function once for each sub pattern. Otherwise, call the function once on the given pattern.

return_ty

Convenience function to get the return type of a function.

search_same

returns list of all pairs (a, b) from exprs such that eq(a, b) hash must be comformed with eq

sext

Turn a constant int byte representation into an i128

span_contains_comment

Checks whether a given span has any comment token This checks for all types of comment: line “//”, block “/**”, doc “///” “//!”

std_or_core

strip_pat_refs

trait_ref_of_method

Gets the hir::TraitRef of the trait the given method is implemented for.

unsext

clip unused bytes

walk_to_expr_usage

Walks the HIR tree from the given expression, up to the node where the value produced by the expression is consumed. Calls the function for every node encountered this way until it returns Some.

with_test_item_names 🔒

Type Definitions

MethodArguments

Arguments of a method: the receiver and all the additional arguments.

Crate clippy_utils

Re-exports

Modules

Macros

Structs

Enums

Statics

Traits

Functions

Type Definitions