mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-23 03:23:33 +00:00
1494 lines
47 KiB
Rust
1494 lines
47 KiB
Rust
#[macro_use]
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pub mod sym;
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#[allow(clippy::module_name_repetitions)]
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pub mod ast_utils;
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pub mod attrs;
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pub mod author;
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pub mod camel_case;
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pub mod comparisons;
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pub mod conf;
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pub mod constants;
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mod diagnostics;
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pub mod higher;
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mod hir_utils;
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pub mod inspector;
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pub mod internal_lints;
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pub mod numeric_literal;
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pub mod paths;
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pub mod ptr;
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pub mod sugg;
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pub mod usage;
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pub use self::attrs::*;
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pub use self::diagnostics::*;
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pub use self::hir_utils::{both, over, SpanlessEq, SpanlessHash};
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use std::borrow::Cow;
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use std::mem;
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use if_chain::if_chain;
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use rustc_ast::ast::{self, Attribute, LitKind};
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use rustc_attr as attr;
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use rustc_errors::Applicability;
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use rustc_hir as hir;
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use rustc_hir::def::{DefKind, Res};
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use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX, LOCAL_CRATE};
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use rustc_hir::intravisit::{NestedVisitorMap, Visitor};
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use rustc_hir::Node;
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use rustc_hir::{
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def, Arm, Block, Body, Constness, Crate, Expr, ExprKind, FnDecl, HirId, ImplItem, ImplItemKind, Item, ItemKind,
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MatchSource, Param, Pat, PatKind, Path, PathSegment, QPath, TraitItem, TraitItemKind, TraitRef, TyKind, Unsafety,
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};
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use rustc_infer::infer::TyCtxtInferExt;
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use rustc_lint::{LateContext, Level, Lint, LintContext};
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use rustc_middle::hir::map::Map;
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use rustc_middle::ty::{self, layout::IntegerExt, subst::GenericArg, Ty, TyCtxt, TypeFoldable};
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use rustc_span::hygiene::{ExpnKind, MacroKind};
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use rustc_span::source_map::original_sp;
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use rustc_span::symbol::{self, kw, Symbol};
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use rustc_span::{BytePos, Pos, Span, DUMMY_SP};
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use rustc_target::abi::Integer;
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use rustc_trait_selection::traits::query::normalize::AtExt;
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use smallvec::SmallVec;
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use crate::consts::{constant, Constant};
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use crate::reexport::Name;
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/// Returns `true` if the two spans come from differing expansions (i.e., one is
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/// from a macro and one isn't).
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#[must_use]
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pub fn differing_macro_contexts(lhs: Span, rhs: Span) -> bool {
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rhs.ctxt() != lhs.ctxt()
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}
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/// Returns `true` if the given `NodeId` is inside a constant context
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///
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/// # Example
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///
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/// ```rust,ignore
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/// if in_constant(cx, expr.hir_id) {
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/// // Do something
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/// }
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/// ```
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pub fn in_constant(cx: &LateContext<'_, '_>, id: HirId) -> bool {
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let parent_id = cx.tcx.hir().get_parent_item(id);
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match cx.tcx.hir().get(parent_id) {
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Node::Item(&Item {
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kind: ItemKind::Const(..) | ItemKind::Static(..),
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..
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})
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| Node::TraitItem(&TraitItem {
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kind: TraitItemKind::Const(..),
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..
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})
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| Node::ImplItem(&ImplItem {
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kind: ImplItemKind::Const(..),
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..
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})
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| Node::AnonConst(_) => true,
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Node::Item(&Item {
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kind: ItemKind::Fn(ref sig, ..),
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..
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})
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| Node::ImplItem(&ImplItem {
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kind: ImplItemKind::Fn(ref sig, _),
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..
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}) => sig.header.constness == Constness::Const,
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_ => false,
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}
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}
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/// Returns `true` if this `span` was expanded by any macro.
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#[must_use]
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pub fn in_macro(span: Span) -> bool {
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if span.from_expansion() {
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if let ExpnKind::Desugaring(..) = span.ctxt().outer_expn_data().kind {
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false
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} else {
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true
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}
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} else {
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false
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}
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}
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// If the snippet is empty, it's an attribute that was inserted during macro
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// expansion and we want to ignore those, because they could come from external
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// sources that the user has no control over.
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// For some reason these attributes don't have any expansion info on them, so
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// we have to check it this way until there is a better way.
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pub fn is_present_in_source<T: LintContext>(cx: &T, span: Span) -> bool {
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if let Some(snippet) = snippet_opt(cx, span) {
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if snippet.is_empty() {
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return false;
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}
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}
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true
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}
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/// Checks if given pattern is a wildcard (`_`)
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pub fn is_wild<'tcx>(pat: &impl std::ops::Deref<Target = Pat<'tcx>>) -> bool {
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match pat.kind {
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PatKind::Wild => true,
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_ => false,
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}
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}
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/// Checks if type is struct, enum or union type with the given def path.
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pub fn match_type(cx: &LateContext<'_, '_>, ty: Ty<'_>, path: &[&str]) -> bool {
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match ty.kind {
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ty::Adt(adt, _) => match_def_path(cx, adt.did, path),
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_ => false,
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}
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}
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/// Checks if the type is equal to a diagnostic item
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pub fn is_type_diagnostic_item(cx: &LateContext<'_, '_>, ty: Ty<'_>, diag_item: Symbol) -> bool {
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match ty.kind {
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ty::Adt(adt, _) => cx.tcx.is_diagnostic_item(diag_item, adt.did),
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_ => false,
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}
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}
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/// Checks if the method call given in `expr` belongs to the given trait.
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pub fn match_trait_method(cx: &LateContext<'_, '_>, expr: &Expr<'_>, path: &[&str]) -> bool {
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let def_id = cx.tables.type_dependent_def_id(expr.hir_id).unwrap();
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let trt_id = cx.tcx.trait_of_item(def_id);
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if let Some(trt_id) = trt_id {
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match_def_path(cx, trt_id, path)
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} else {
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false
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}
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}
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/// Checks if an expression references a variable of the given name.
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pub fn match_var(expr: &Expr<'_>, var: Name) -> bool {
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if let ExprKind::Path(QPath::Resolved(None, ref path)) = expr.kind {
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if let [p] = path.segments {
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return p.ident.name == var;
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}
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}
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false
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}
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pub fn last_path_segment<'tcx>(path: &QPath<'tcx>) -> &'tcx PathSegment<'tcx> {
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match *path {
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QPath::Resolved(_, ref path) => path.segments.last().expect("A path must have at least one segment"),
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QPath::TypeRelative(_, ref seg) => seg,
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}
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}
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pub fn single_segment_path<'tcx>(path: &QPath<'tcx>) -> Option<&'tcx PathSegment<'tcx>> {
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match *path {
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QPath::Resolved(_, ref path) => path.segments.get(0),
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QPath::TypeRelative(_, ref seg) => Some(seg),
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}
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}
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/// Matches a `QPath` against a slice of segment string literals.
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///
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/// There is also `match_path` if you are dealing with a `rustc_hir::Path` instead of a
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/// `rustc_hir::QPath`.
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///
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/// # Examples
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/// ```rust,ignore
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/// match_qpath(path, &["std", "rt", "begin_unwind"])
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/// ```
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pub fn match_qpath(path: &QPath<'_>, segments: &[&str]) -> bool {
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match *path {
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QPath::Resolved(_, ref path) => match_path(path, segments),
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QPath::TypeRelative(ref ty, ref segment) => match ty.kind {
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TyKind::Path(ref inner_path) => {
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if let [prefix @ .., end] = segments {
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if match_qpath(inner_path, prefix) {
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return segment.ident.name.as_str() == *end;
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}
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}
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false
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},
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_ => false,
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},
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}
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}
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/// Matches a `Path` against a slice of segment string literals.
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///
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/// There is also `match_qpath` if you are dealing with a `rustc_hir::QPath` instead of a
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/// `rustc_hir::Path`.
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///
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/// # Examples
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///
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/// ```rust,ignore
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/// if match_path(&trait_ref.path, &paths::HASH) {
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/// // This is the `std::hash::Hash` trait.
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/// }
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///
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/// if match_path(ty_path, &["rustc", "lint", "Lint"]) {
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/// // This is a `rustc_middle::lint::Lint`.
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/// }
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/// ```
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pub fn match_path(path: &Path<'_>, segments: &[&str]) -> bool {
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path.segments
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.iter()
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.rev()
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.zip(segments.iter().rev())
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.all(|(a, b)| a.ident.name.as_str() == *b)
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}
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/// Matches a `Path` against a slice of segment string literals, e.g.
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///
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/// # Examples
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/// ```rust,ignore
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/// match_path_ast(path, &["std", "rt", "begin_unwind"])
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/// ```
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pub fn match_path_ast(path: &ast::Path, segments: &[&str]) -> bool {
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path.segments
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.iter()
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.rev()
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.zip(segments.iter().rev())
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.all(|(a, b)| a.ident.name.as_str() == *b)
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}
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/// Gets the definition associated to a path.
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pub fn path_to_res(cx: &LateContext<'_, '_>, path: &[&str]) -> Option<def::Res> {
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let crates = cx.tcx.crates();
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let krate = crates
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.iter()
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.find(|&&krate| cx.tcx.crate_name(krate).as_str() == path[0]);
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if let Some(krate) = krate {
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let krate = DefId {
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krate: *krate,
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index: CRATE_DEF_INDEX,
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};
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let mut items = cx.tcx.item_children(krate);
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let mut path_it = path.iter().skip(1).peekable();
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loop {
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let segment = match path_it.next() {
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Some(segment) => segment,
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None => return None,
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};
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let result = SmallVec::<[_; 8]>::new();
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for item in mem::replace(&mut items, cx.tcx.arena.alloc_slice(&result)).iter() {
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if item.ident.name.as_str() == *segment {
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if path_it.peek().is_none() {
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return Some(item.res);
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}
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items = cx.tcx.item_children(item.res.def_id());
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break;
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}
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}
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}
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} else {
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None
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}
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}
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pub fn qpath_res(cx: &LateContext<'_, '_>, qpath: &hir::QPath<'_>, id: hir::HirId) -> Res {
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match qpath {
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hir::QPath::Resolved(_, path) => path.res,
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hir::QPath::TypeRelative(..) => {
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if cx.tcx.has_typeck_tables(id.owner.to_def_id()) {
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cx.tcx
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.typeck_tables_of(id.owner.to_def_id().expect_local())
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.qpath_res(qpath, id)
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} else {
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Res::Err
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}
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},
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}
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}
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/// Convenience function to get the `DefId` of a trait by path.
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/// It could be a trait or trait alias.
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pub fn get_trait_def_id(cx: &LateContext<'_, '_>, path: &[&str]) -> Option<DefId> {
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let res = match path_to_res(cx, path) {
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Some(res) => res,
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None => return None,
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};
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match res {
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Res::Def(DefKind::Trait | DefKind::TraitAlias, trait_id) => Some(trait_id),
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Res::Err => unreachable!("this trait resolution is impossible: {:?}", &path),
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_ => None,
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}
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}
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/// Checks whether a type implements a trait.
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/// See also `get_trait_def_id`.
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pub fn implements_trait<'a, 'tcx>(
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cx: &LateContext<'a, 'tcx>,
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ty: Ty<'tcx>,
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trait_id: DefId,
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ty_params: &[GenericArg<'tcx>],
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) -> bool {
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// Do not check on infer_types to avoid panic in evaluate_obligation.
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if ty.has_infer_types() {
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return false;
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}
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let ty = cx.tcx.erase_regions(&ty);
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let ty_params = cx.tcx.mk_substs(ty_params.iter());
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cx.tcx.type_implements_trait((trait_id, ty, ty_params, cx.param_env))
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}
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/// Gets the `hir::TraitRef` of the trait the given method is implemented for.
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///
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/// Use this if you want to find the `TraitRef` of the `Add` trait in this example:
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///
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/// ```rust
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/// struct Point(isize, isize);
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///
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/// impl std::ops::Add for Point {
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/// type Output = Self;
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///
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/// fn add(self, other: Self) -> Self {
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/// Point(0, 0)
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/// }
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/// }
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/// ```
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pub fn trait_ref_of_method<'tcx>(cx: &LateContext<'_, 'tcx>, hir_id: HirId) -> Option<&'tcx TraitRef<'tcx>> {
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// Get the implemented trait for the current function
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let parent_impl = cx.tcx.hir().get_parent_item(hir_id);
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if_chain! {
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if parent_impl != hir::CRATE_HIR_ID;
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if let hir::Node::Item(item) = cx.tcx.hir().get(parent_impl);
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if let hir::ItemKind::Impl{ of_trait: trait_ref, .. } = &item.kind;
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then { return trait_ref.as_ref(); }
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}
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None
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}
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/// Checks whether this type implements `Drop`.
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pub fn has_drop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
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match ty.ty_adt_def() {
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Some(def) => def.has_dtor(cx.tcx),
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None => false,
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}
|
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}
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/// Returns the method names and argument list of nested method call expressions that make up
|
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/// `expr`. method/span lists are sorted with the most recent call first.
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pub fn method_calls<'tcx>(
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expr: &'tcx Expr<'tcx>,
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max_depth: usize,
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) -> (Vec<Symbol>, Vec<&'tcx [Expr<'tcx>]>, Vec<Span>) {
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let mut method_names = Vec::with_capacity(max_depth);
|
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let mut arg_lists = Vec::with_capacity(max_depth);
|
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let mut spans = Vec::with_capacity(max_depth);
|
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|
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let mut current = expr;
|
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for _ in 0..max_depth {
|
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if let ExprKind::MethodCall(path, span, args, _) = ¤t.kind {
|
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if args.iter().any(|e| e.span.from_expansion()) {
|
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break;
|
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}
|
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method_names.push(path.ident.name);
|
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arg_lists.push(&**args);
|
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spans.push(*span);
|
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current = &args[0];
|
||
} else {
|
||
break;
|
||
}
|
||
}
|
||
|
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(method_names, arg_lists, spans)
|
||
}
|
||
|
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/// Matches an `Expr` against a chain of methods, and return the matched `Expr`s.
|
||
///
|
||
/// For example, if `expr` represents the `.baz()` in `foo.bar().baz()`,
|
||
/// `method_chain_args(expr, &["bar", "baz"])` will return a `Vec`
|
||
/// containing the `Expr`s for
|
||
/// `.bar()` and `.baz()`
|
||
pub fn method_chain_args<'a>(expr: &'a Expr<'_>, methods: &[&str]) -> Option<Vec<&'a [Expr<'a>]>> {
|
||
let mut current = expr;
|
||
let mut matched = Vec::with_capacity(methods.len());
|
||
for method_name in methods.iter().rev() {
|
||
// method chains are stored last -> first
|
||
if let ExprKind::MethodCall(ref path, _, ref args, _) = current.kind {
|
||
if path.ident.name.as_str() == *method_name {
|
||
if args.iter().any(|e| e.span.from_expansion()) {
|
||
return None;
|
||
}
|
||
matched.push(&**args); // build up `matched` backwards
|
||
current = &args[0] // go to parent expression
|
||
} else {
|
||
return None;
|
||
}
|
||
} else {
|
||
return None;
|
||
}
|
||
}
|
||
// Reverse `matched` so that it is in the same order as `methods`.
|
||
matched.reverse();
|
||
Some(matched)
|
||
}
|
||
|
||
/// Returns `true` if the provided `def_id` is an entrypoint to a program.
|
||
pub fn is_entrypoint_fn(cx: &LateContext<'_, '_>, def_id: DefId) -> bool {
|
||
cx.tcx
|
||
.entry_fn(LOCAL_CRATE)
|
||
.map_or(false, |(entry_fn_def_id, _)| def_id == entry_fn_def_id.to_def_id())
|
||
}
|
||
|
||
/// Gets the name of the item the expression is in, if available.
|
||
pub fn get_item_name(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> Option<Name> {
|
||
let parent_id = cx.tcx.hir().get_parent_item(expr.hir_id);
|
||
match cx.tcx.hir().find(parent_id) {
|
||
Some(
|
||
Node::Item(Item { ident, .. })
|
||
| Node::TraitItem(TraitItem { ident, .. })
|
||
| Node::ImplItem(ImplItem { ident, .. }),
|
||
) => Some(ident.name),
|
||
_ => None,
|
||
}
|
||
}
|
||
|
||
/// Gets the name of a `Pat`, if any.
|
||
pub fn get_pat_name(pat: &Pat<'_>) -> Option<Name> {
|
||
match pat.kind {
|
||
PatKind::Binding(.., ref spname, _) => Some(spname.name),
|
||
PatKind::Path(ref qpath) => single_segment_path(qpath).map(|ps| ps.ident.name),
|
||
PatKind::Box(ref p) | PatKind::Ref(ref p, _) => get_pat_name(&*p),
|
||
_ => None,
|
||
}
|
||
}
|
||
|
||
struct ContainsName {
|
||
name: Name,
|
||
result: bool,
|
||
}
|
||
|
||
impl<'tcx> Visitor<'tcx> for ContainsName {
|
||
type Map = Map<'tcx>;
|
||
|
||
fn visit_name(&mut self, _: Span, name: Name) {
|
||
if self.name == name {
|
||
self.result = true;
|
||
}
|
||
}
|
||
fn nested_visit_map(&mut self) -> NestedVisitorMap<Self::Map> {
|
||
NestedVisitorMap::None
|
||
}
|
||
}
|
||
|
||
/// Checks if an `Expr` contains a certain name.
|
||
pub fn contains_name(name: Name, expr: &Expr<'_>) -> bool {
|
||
let mut cn = ContainsName { name, result: false };
|
||
cn.visit_expr(expr);
|
||
cn.result
|
||
}
|
||
|
||
/// Converts a span to a code snippet if available, otherwise use default.
|
||
///
|
||
/// This is useful if you want to provide suggestions for your lint or more generally, if you want
|
||
/// to convert a given `Span` to a `str`.
|
||
///
|
||
/// # Example
|
||
/// ```rust,ignore
|
||
/// snippet(cx, expr.span, "..")
|
||
/// ```
|
||
pub fn snippet<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
|
||
snippet_opt(cx, span).map_or_else(|| Cow::Borrowed(default), From::from)
|
||
}
|
||
|
||
/// Same as `snippet`, but it adapts the applicability level by following rules:
|
||
///
|
||
/// - Applicability level `Unspecified` will never be changed.
|
||
/// - If the span is inside a macro, change the applicability level to `MaybeIncorrect`.
|
||
/// - If the default value is used and the applicability level is `MachineApplicable`, change it to
|
||
/// `HasPlaceholders`
|
||
pub fn snippet_with_applicability<'a, T: LintContext>(
|
||
cx: &T,
|
||
span: Span,
|
||
default: &'a str,
|
||
applicability: &mut Applicability,
|
||
) -> Cow<'a, str> {
|
||
if *applicability != Applicability::Unspecified && span.from_expansion() {
|
||
*applicability = Applicability::MaybeIncorrect;
|
||
}
|
||
snippet_opt(cx, span).map_or_else(
|
||
|| {
|
||
if *applicability == Applicability::MachineApplicable {
|
||
*applicability = Applicability::HasPlaceholders;
|
||
}
|
||
Cow::Borrowed(default)
|
||
},
|
||
From::from,
|
||
)
|
||
}
|
||
|
||
/// Same as `snippet`, but should only be used when it's clear that the input span is
|
||
/// not a macro argument.
|
||
pub fn snippet_with_macro_callsite<'a, T: LintContext>(cx: &T, span: Span, default: &'a str) -> Cow<'a, str> {
|
||
snippet(cx, span.source_callsite(), default)
|
||
}
|
||
|
||
/// Converts a span to a code snippet. Returns `None` if not available.
|
||
pub fn snippet_opt<T: LintContext>(cx: &T, span: Span) -> Option<String> {
|
||
cx.sess().source_map().span_to_snippet(span).ok()
|
||
}
|
||
|
||
/// Converts a span (from a block) to a code snippet if available, otherwise use default.
|
||
///
|
||
/// This trims the code of indentation, except for the first line. Use it for blocks or block-like
|
||
/// things which need to be printed as such.
|
||
///
|
||
/// The `indent_relative_to` arg can be used, to provide a span, where the indentation of the
|
||
/// resulting snippet of the given span.
|
||
///
|
||
/// # Example
|
||
///
|
||
/// ```rust,ignore
|
||
/// snippet_block(cx, block.span, "..", None)
|
||
/// // where, `block` is the block of the if expr
|
||
/// if x {
|
||
/// y;
|
||
/// }
|
||
/// // will return the snippet
|
||
/// {
|
||
/// y;
|
||
/// }
|
||
/// ```
|
||
///
|
||
/// ```rust,ignore
|
||
/// snippet_block(cx, block.span, "..", Some(if_expr.span))
|
||
/// // where, `block` is the block of the if expr
|
||
/// if x {
|
||
/// y;
|
||
/// }
|
||
/// // will return the snippet
|
||
/// {
|
||
/// y;
|
||
/// } // aligned with `if`
|
||
/// ```
|
||
/// Note that the first line of the snippet always has 0 indentation.
|
||
pub fn snippet_block<'a, T: LintContext>(
|
||
cx: &T,
|
||
span: Span,
|
||
default: &'a str,
|
||
indent_relative_to: Option<Span>,
|
||
) -> Cow<'a, str> {
|
||
let snip = snippet(cx, span, default);
|
||
let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
|
||
trim_multiline(snip, true, indent)
|
||
}
|
||
|
||
/// Same as `snippet_block`, but adapts the applicability level by the rules of
|
||
/// `snippet_with_applicabiliy`.
|
||
pub fn snippet_block_with_applicability<'a, T: LintContext>(
|
||
cx: &T,
|
||
span: Span,
|
||
default: &'a str,
|
||
indent_relative_to: Option<Span>,
|
||
applicability: &mut Applicability,
|
||
) -> Cow<'a, str> {
|
||
let snip = snippet_with_applicability(cx, span, default, applicability);
|
||
let indent = indent_relative_to.and_then(|s| indent_of(cx, s));
|
||
trim_multiline(snip, true, indent)
|
||
}
|
||
|
||
/// Returns a new Span that extends the original Span to the first non-whitespace char of the first
|
||
/// line.
|
||
///
|
||
/// ```rust,ignore
|
||
/// let x = ();
|
||
/// // ^^
|
||
/// // will be converted to
|
||
/// let x = ();
|
||
/// // ^^^^^^^^^^
|
||
/// ```
|
||
pub fn first_line_of_span<T: LintContext>(cx: &T, span: Span) -> Span {
|
||
if let Some(first_char_pos) = first_char_in_first_line(cx, span) {
|
||
span.with_lo(first_char_pos)
|
||
} else {
|
||
span
|
||
}
|
||
}
|
||
|
||
fn first_char_in_first_line<T: LintContext>(cx: &T, span: Span) -> Option<BytePos> {
|
||
let line_span = line_span(cx, span);
|
||
if let Some(snip) = snippet_opt(cx, line_span) {
|
||
snip.find(|c: char| !c.is_whitespace())
|
||
.map(|pos| line_span.lo() + BytePos::from_usize(pos))
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Returns the indentation of the line of a span
|
||
///
|
||
/// ```rust,ignore
|
||
/// let x = ();
|
||
/// // ^^ -- will return 0
|
||
/// let x = ();
|
||
/// // ^^ -- will return 4
|
||
/// ```
|
||
pub fn indent_of<T: LintContext>(cx: &T, span: Span) -> Option<usize> {
|
||
if let Some(snip) = snippet_opt(cx, line_span(cx, span)) {
|
||
snip.find(|c: char| !c.is_whitespace())
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Extends the span to the beginning of the spans line, incl. whitespaces.
|
||
///
|
||
/// ```rust,ignore
|
||
/// let x = ();
|
||
/// // ^^
|
||
/// // will be converted to
|
||
/// let x = ();
|
||
/// // ^^^^^^^^^^^^^^
|
||
/// ```
|
||
fn line_span<T: LintContext>(cx: &T, span: Span) -> Span {
|
||
let span = original_sp(span, DUMMY_SP);
|
||
let source_map_and_line = cx.sess().source_map().lookup_line(span.lo()).unwrap();
|
||
let line_no = source_map_and_line.line;
|
||
let line_start = source_map_and_line.sf.lines[line_no];
|
||
Span::new(line_start, span.hi(), span.ctxt())
|
||
}
|
||
|
||
/// Like `snippet_block`, but add braces if the expr is not an `ExprKind::Block`.
|
||
/// Also takes an `Option<String>` which can be put inside the braces.
|
||
pub fn expr_block<'a, T: LintContext>(
|
||
cx: &T,
|
||
expr: &Expr<'_>,
|
||
option: Option<String>,
|
||
default: &'a str,
|
||
indent_relative_to: Option<Span>,
|
||
) -> Cow<'a, str> {
|
||
let code = snippet_block(cx, expr.span, default, indent_relative_to);
|
||
let string = option.unwrap_or_default();
|
||
if expr.span.from_expansion() {
|
||
Cow::Owned(format!("{{ {} }}", snippet_with_macro_callsite(cx, expr.span, default)))
|
||
} else if let ExprKind::Block(_, _) = expr.kind {
|
||
Cow::Owned(format!("{}{}", code, string))
|
||
} else if string.is_empty() {
|
||
Cow::Owned(format!("{{ {} }}", code))
|
||
} else {
|
||
Cow::Owned(format!("{{\n{};\n{}\n}}", code, string))
|
||
}
|
||
}
|
||
|
||
/// Trim indentation from a multiline string with possibility of ignoring the
|
||
/// first line.
|
||
fn trim_multiline(s: Cow<'_, str>, ignore_first: bool, indent: Option<usize>) -> Cow<'_, str> {
|
||
let s_space = trim_multiline_inner(s, ignore_first, indent, ' ');
|
||
let s_tab = trim_multiline_inner(s_space, ignore_first, indent, '\t');
|
||
trim_multiline_inner(s_tab, ignore_first, indent, ' ')
|
||
}
|
||
|
||
fn trim_multiline_inner(s: Cow<'_, str>, ignore_first: bool, indent: Option<usize>, ch: char) -> Cow<'_, str> {
|
||
let mut x = s
|
||
.lines()
|
||
.skip(ignore_first as usize)
|
||
.filter_map(|l| {
|
||
if l.is_empty() {
|
||
None
|
||
} else {
|
||
// ignore empty lines
|
||
Some(l.char_indices().find(|&(_, x)| x != ch).unwrap_or((l.len(), ch)).0)
|
||
}
|
||
})
|
||
.min()
|
||
.unwrap_or(0);
|
||
if let Some(indent) = indent {
|
||
x = x.saturating_sub(indent);
|
||
}
|
||
if x > 0 {
|
||
Cow::Owned(
|
||
s.lines()
|
||
.enumerate()
|
||
.map(|(i, l)| {
|
||
if (ignore_first && i == 0) || l.is_empty() {
|
||
l
|
||
} else {
|
||
l.split_at(x).1
|
||
}
|
||
})
|
||
.collect::<Vec<_>>()
|
||
.join("\n"),
|
||
)
|
||
} else {
|
||
s
|
||
}
|
||
}
|
||
|
||
/// Gets the parent expression, if any –- this is useful to constrain a lint.
|
||
pub fn get_parent_expr<'c>(cx: &'c LateContext<'_, '_>, e: &Expr<'_>) -> Option<&'c Expr<'c>> {
|
||
let map = &cx.tcx.hir();
|
||
let hir_id = e.hir_id;
|
||
let parent_id = map.get_parent_node(hir_id);
|
||
if hir_id == parent_id {
|
||
return None;
|
||
}
|
||
map.find(parent_id).and_then(|node| {
|
||
if let Node::Expr(parent) = node {
|
||
Some(parent)
|
||
} else {
|
||
None
|
||
}
|
||
})
|
||
}
|
||
|
||
pub fn get_enclosing_block<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, hir_id: HirId) -> Option<&'tcx Block<'tcx>> {
|
||
let map = &cx.tcx.hir();
|
||
let enclosing_node = map
|
||
.get_enclosing_scope(hir_id)
|
||
.and_then(|enclosing_id| map.find(enclosing_id));
|
||
if let Some(node) = enclosing_node {
|
||
match node {
|
||
Node::Block(block) => Some(block),
|
||
Node::Item(&Item {
|
||
kind: ItemKind::Fn(_, _, eid),
|
||
..
|
||
})
|
||
| Node::ImplItem(&ImplItem {
|
||
kind: ImplItemKind::Fn(_, eid),
|
||
..
|
||
}) => match cx.tcx.hir().body(eid).value.kind {
|
||
ExprKind::Block(ref block, _) => Some(block),
|
||
_ => None,
|
||
},
|
||
_ => None,
|
||
}
|
||
} else {
|
||
None
|
||
}
|
||
}
|
||
|
||
/// Returns the base type for HIR references and pointers.
|
||
pub fn walk_ptrs_hir_ty<'tcx>(ty: &'tcx hir::Ty<'tcx>) -> &'tcx hir::Ty<'tcx> {
|
||
match ty.kind {
|
||
TyKind::Ptr(ref mut_ty) | TyKind::Rptr(_, ref mut_ty) => walk_ptrs_hir_ty(&mut_ty.ty),
|
||
_ => ty,
|
||
}
|
||
}
|
||
|
||
/// Returns the base type for references and raw pointers.
|
||
pub fn walk_ptrs_ty(ty: Ty<'_>) -> Ty<'_> {
|
||
match ty.kind {
|
||
ty::Ref(_, ty, _) => walk_ptrs_ty(ty),
|
||
_ => ty,
|
||
}
|
||
}
|
||
|
||
/// Returns the base type for references and raw pointers, and count reference
|
||
/// depth.
|
||
pub fn walk_ptrs_ty_depth(ty: Ty<'_>) -> (Ty<'_>, usize) {
|
||
fn inner(ty: Ty<'_>, depth: usize) -> (Ty<'_>, usize) {
|
||
match ty.kind {
|
||
ty::Ref(_, ty, _) => inner(ty, depth + 1),
|
||
_ => (ty, depth),
|
||
}
|
||
}
|
||
inner(ty, 0)
|
||
}
|
||
|
||
/// Checks whether the given expression is a constant integer of the given value.
|
||
/// unlike `is_integer_literal`, this version does const folding
|
||
pub fn is_integer_const(cx: &LateContext<'_, '_>, e: &Expr<'_>, value: u128) -> bool {
|
||
if is_integer_literal(e, value) {
|
||
return true;
|
||
}
|
||
let map = cx.tcx.hir();
|
||
let parent_item = map.get_parent_item(e.hir_id);
|
||
if let Some((Constant::Int(v), _)) = map
|
||
.maybe_body_owned_by(parent_item)
|
||
.and_then(|body_id| constant(cx, cx.tcx.body_tables(body_id), e))
|
||
{
|
||
value == v
|
||
} else {
|
||
false
|
||
}
|
||
}
|
||
|
||
/// Checks whether the given expression is a constant literal of the given value.
|
||
pub fn is_integer_literal(expr: &Expr<'_>, value: u128) -> bool {
|
||
// FIXME: use constant folding
|
||
if let ExprKind::Lit(ref spanned) = expr.kind {
|
||
if let LitKind::Int(v, _) = spanned.node {
|
||
return v == value;
|
||
}
|
||
}
|
||
false
|
||
}
|
||
|
||
/// Returns `true` if the given `Expr` has been coerced before.
|
||
///
|
||
/// Examples of coercions can be found in the Nomicon at
|
||
/// <https://doc.rust-lang.org/nomicon/coercions.html>.
|
||
///
|
||
/// See `rustc_middle::ty::adjustment::Adjustment` and `rustc_typeck::check::coercion` for more
|
||
/// information on adjustments and coercions.
|
||
pub fn is_adjusted(cx: &LateContext<'_, '_>, e: &Expr<'_>) -> bool {
|
||
cx.tables.adjustments().get(e.hir_id).is_some()
|
||
}
|
||
|
||
/// Returns the pre-expansion span if is this comes from an expansion of the
|
||
/// macro `name`.
|
||
/// See also `is_direct_expn_of`.
|
||
#[must_use]
|
||
pub fn is_expn_of(mut span: Span, name: &str) -> Option<Span> {
|
||
loop {
|
||
if span.from_expansion() {
|
||
let data = span.ctxt().outer_expn_data();
|
||
let new_span = data.call_site;
|
||
|
||
if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind {
|
||
if mac_name.as_str() == name {
|
||
return Some(new_span);
|
||
}
|
||
}
|
||
|
||
span = new_span;
|
||
} else {
|
||
return None;
|
||
}
|
||
}
|
||
}
|
||
|
||
/// 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
|
||
/// ```rust,ignore
|
||
/// foo!(bar!(42));
|
||
/// ```
|
||
/// `42` is considered expanded from `foo!` and `bar!` by `is_expn_of` but only
|
||
/// `bar!` by
|
||
/// `is_direct_expn_of`.
|
||
#[must_use]
|
||
pub fn is_direct_expn_of(span: Span, name: &str) -> Option<Span> {
|
||
if span.from_expansion() {
|
||
let data = span.ctxt().outer_expn_data();
|
||
let new_span = data.call_site;
|
||
|
||
if let ExpnKind::Macro(MacroKind::Bang, mac_name) = data.kind {
|
||
if mac_name.as_str() == name {
|
||
return Some(new_span);
|
||
}
|
||
}
|
||
}
|
||
|
||
None
|
||
}
|
||
|
||
/// Convenience function to get the return type of a function.
|
||
pub fn return_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, fn_item: hir::HirId) -> Ty<'tcx> {
|
||
let fn_def_id = cx.tcx.hir().local_def_id(fn_item);
|
||
let ret_ty = cx.tcx.fn_sig(fn_def_id).output();
|
||
cx.tcx.erase_late_bound_regions(&ret_ty)
|
||
}
|
||
|
||
/// Returns `true` if the given type is an `unsafe` function.
|
||
pub fn type_is_unsafe_function<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
|
||
match ty.kind {
|
||
ty::FnDef(..) | ty::FnPtr(_) => ty.fn_sig(cx.tcx).unsafety() == Unsafety::Unsafe,
|
||
_ => false,
|
||
}
|
||
}
|
||
|
||
pub fn is_copy<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
|
||
ty.is_copy_modulo_regions(cx.tcx.at(DUMMY_SP), cx.param_env)
|
||
}
|
||
|
||
/// Checks if an expression is constructing a tuple-like enum variant or struct
|
||
pub fn is_ctor_or_promotable_const_function(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
|
||
if let ExprKind::Call(ref fun, _) = expr.kind {
|
||
if let ExprKind::Path(ref qp) = fun.kind {
|
||
let res = cx.tables.qpath_res(qp, fun.hir_id);
|
||
return match res {
|
||
def::Res::Def(DefKind::Variant | DefKind::Ctor(..), ..) => true,
|
||
def::Res::Def(_, def_id) => cx.tcx.is_promotable_const_fn(def_id),
|
||
_ => false,
|
||
};
|
||
}
|
||
}
|
||
false
|
||
}
|
||
|
||
/// Returns `true` if a pattern is refutable.
|
||
// TODO: should be implemented using rustc/mir_build/hair machinery
|
||
pub fn is_refutable(cx: &LateContext<'_, '_>, pat: &Pat<'_>) -> bool {
|
||
fn is_enum_variant(cx: &LateContext<'_, '_>, qpath: &QPath<'_>, id: HirId) -> bool {
|
||
matches!(
|
||
cx.tables.qpath_res(qpath, id),
|
||
def::Res::Def(DefKind::Variant, ..) | Res::Def(DefKind::Ctor(def::CtorOf::Variant, _), _)
|
||
)
|
||
}
|
||
|
||
fn are_refutable<'a, I: Iterator<Item = &'a Pat<'a>>>(cx: &LateContext<'_, '_>, mut i: I) -> bool {
|
||
i.any(|pat| is_refutable(cx, pat))
|
||
}
|
||
|
||
match pat.kind {
|
||
PatKind::Wild => false,
|
||
PatKind::Binding(_, _, _, pat) => pat.map_or(false, |pat| is_refutable(cx, pat)),
|
||
PatKind::Box(ref pat) | PatKind::Ref(ref pat, _) => is_refutable(cx, pat),
|
||
PatKind::Lit(..) | PatKind::Range(..) => true,
|
||
PatKind::Path(ref qpath) => is_enum_variant(cx, qpath, pat.hir_id),
|
||
PatKind::Or(ref pats) => {
|
||
// TODO: should be the honest check, that pats is exhaustive set
|
||
are_refutable(cx, pats.iter().map(|pat| &**pat))
|
||
},
|
||
PatKind::Tuple(ref pats, _) => are_refutable(cx, pats.iter().map(|pat| &**pat)),
|
||
PatKind::Struct(ref qpath, ref fields, _) => {
|
||
is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, fields.iter().map(|field| &*field.pat))
|
||
},
|
||
PatKind::TupleStruct(ref qpath, ref pats, _) => {
|
||
is_enum_variant(cx, qpath, pat.hir_id) || are_refutable(cx, pats.iter().map(|pat| &**pat))
|
||
},
|
||
PatKind::Slice(ref head, ref middle, ref tail) => {
|
||
match &cx.tables.node_type(pat.hir_id).kind {
|
||
ty::Slice(..) => {
|
||
// [..] is the only irrefutable slice pattern.
|
||
!head.is_empty() || middle.is_none() || !tail.is_empty()
|
||
},
|
||
ty::Array(..) => are_refutable(cx, head.iter().chain(middle).chain(tail.iter()).map(|pat| &**pat)),
|
||
_ => {
|
||
// unreachable!()
|
||
true
|
||
},
|
||
}
|
||
},
|
||
}
|
||
}
|
||
|
||
/// Checks for the `#[automatically_derived]` attribute all `#[derive]`d
|
||
/// implementations have.
|
||
pub fn is_automatically_derived(attrs: &[ast::Attribute]) -> bool {
|
||
attr::contains_name(attrs, sym!(automatically_derived))
|
||
}
|
||
|
||
/// Remove blocks around an expression.
|
||
///
|
||
/// Ie. `x`, `{ x }` and `{{{{ x }}}}` all give `x`. `{ x; y }` and `{}` return
|
||
/// themselves.
|
||
pub fn remove_blocks<'tcx>(mut expr: &'tcx Expr<'tcx>) -> &'tcx Expr<'tcx> {
|
||
while let ExprKind::Block(ref block, ..) = expr.kind {
|
||
match (block.stmts.is_empty(), block.expr.as_ref()) {
|
||
(true, Some(e)) => expr = e,
|
||
_ => break,
|
||
}
|
||
}
|
||
expr
|
||
}
|
||
|
||
pub fn is_self(slf: &Param<'_>) -> bool {
|
||
if let PatKind::Binding(.., name, _) = slf.pat.kind {
|
||
name.name == kw::SelfLower
|
||
} else {
|
||
false
|
||
}
|
||
}
|
||
|
||
pub fn is_self_ty(slf: &hir::Ty<'_>) -> bool {
|
||
if_chain! {
|
||
if let TyKind::Path(ref qp) = slf.kind;
|
||
if let QPath::Resolved(None, ref path) = *qp;
|
||
if let Res::SelfTy(..) = path.res;
|
||
then {
|
||
return true
|
||
}
|
||
}
|
||
false
|
||
}
|
||
|
||
pub fn iter_input_pats<'tcx>(decl: &FnDecl<'_>, body: &'tcx Body<'_>) -> impl Iterator<Item = &'tcx Param<'tcx>> {
|
||
(0..decl.inputs.len()).map(move |i| &body.params[i])
|
||
}
|
||
|
||
/// Checks if a given expression is a match expression expanded from the `?`
|
||
/// operator or the `try` macro.
|
||
pub fn is_try<'tcx>(expr: &'tcx Expr<'tcx>) -> Option<&'tcx Expr<'tcx>> {
|
||
fn is_ok(arm: &Arm<'_>) -> bool {
|
||
if_chain! {
|
||
if let PatKind::TupleStruct(ref path, ref pat, None) = arm.pat.kind;
|
||
if match_qpath(path, &paths::RESULT_OK[1..]);
|
||
if let PatKind::Binding(_, hir_id, _, None) = pat[0].kind;
|
||
if let ExprKind::Path(QPath::Resolved(None, ref path)) = arm.body.kind;
|
||
if let Res::Local(lid) = path.res;
|
||
if lid == hir_id;
|
||
then {
|
||
return true;
|
||
}
|
||
}
|
||
false
|
||
}
|
||
|
||
fn is_err(arm: &Arm<'_>) -> bool {
|
||
if let PatKind::TupleStruct(ref path, _, _) = arm.pat.kind {
|
||
match_qpath(path, &paths::RESULT_ERR[1..])
|
||
} else {
|
||
false
|
||
}
|
||
}
|
||
|
||
if let ExprKind::Match(_, ref arms, ref source) = expr.kind {
|
||
// desugared from a `?` operator
|
||
if let MatchSource::TryDesugar = *source {
|
||
return Some(expr);
|
||
}
|
||
|
||
if_chain! {
|
||
if arms.len() == 2;
|
||
if arms[0].guard.is_none();
|
||
if arms[1].guard.is_none();
|
||
if (is_ok(&arms[0]) && is_err(&arms[1])) ||
|
||
(is_ok(&arms[1]) && is_err(&arms[0]));
|
||
then {
|
||
return Some(expr);
|
||
}
|
||
}
|
||
}
|
||
|
||
None
|
||
}
|
||
|
||
/// Returns `true` if the lint is allowed in the current context
|
||
///
|
||
/// Useful for skipping long running code when it's unnecessary
|
||
pub fn is_allowed(cx: &LateContext<'_, '_>, lint: &'static Lint, id: HirId) -> bool {
|
||
cx.tcx.lint_level_at_node(lint, id).0 == Level::Allow
|
||
}
|
||
|
||
pub fn get_arg_name(pat: &Pat<'_>) -> Option<Name> {
|
||
match pat.kind {
|
||
PatKind::Binding(.., ident, None) => Some(ident.name),
|
||
PatKind::Ref(ref subpat, _) => get_arg_name(subpat),
|
||
_ => None,
|
||
}
|
||
}
|
||
|
||
pub fn int_bits(tcx: TyCtxt<'_>, ity: ast::IntTy) -> u64 {
|
||
Integer::from_attr(&tcx, attr::IntType::SignedInt(ity)).size().bits()
|
||
}
|
||
|
||
#[allow(clippy::cast_possible_wrap)]
|
||
/// Turn a constant int byte representation into an i128
|
||
pub fn sext(tcx: TyCtxt<'_>, u: u128, ity: ast::IntTy) -> i128 {
|
||
let amt = 128 - int_bits(tcx, ity);
|
||
((u as i128) << amt) >> amt
|
||
}
|
||
|
||
#[allow(clippy::cast_sign_loss)]
|
||
/// clip unused bytes
|
||
pub fn unsext(tcx: TyCtxt<'_>, u: i128, ity: ast::IntTy) -> u128 {
|
||
let amt = 128 - int_bits(tcx, ity);
|
||
((u as u128) << amt) >> amt
|
||
}
|
||
|
||
/// clip unused bytes
|
||
pub fn clip(tcx: TyCtxt<'_>, u: u128, ity: ast::UintTy) -> u128 {
|
||
let bits = Integer::from_attr(&tcx, attr::IntType::UnsignedInt(ity)).size().bits();
|
||
let amt = 128 - bits;
|
||
(u << amt) >> amt
|
||
}
|
||
|
||
/// Removes block comments from the given `Vec` of lines.
|
||
///
|
||
/// # Examples
|
||
///
|
||
/// ```rust,ignore
|
||
/// without_block_comments(vec!["/*", "foo", "*/"]);
|
||
/// // => vec![]
|
||
///
|
||
/// without_block_comments(vec!["bar", "/*", "foo", "*/"]);
|
||
/// // => vec!["bar"]
|
||
/// ```
|
||
pub fn without_block_comments(lines: Vec<&str>) -> Vec<&str> {
|
||
let mut without = vec![];
|
||
|
||
let mut nest_level = 0;
|
||
|
||
for line in lines {
|
||
if line.contains("/*") {
|
||
nest_level += 1;
|
||
continue;
|
||
} else if line.contains("*/") {
|
||
nest_level -= 1;
|
||
continue;
|
||
}
|
||
|
||
if nest_level == 0 {
|
||
without.push(line);
|
||
}
|
||
}
|
||
|
||
without
|
||
}
|
||
|
||
pub fn any_parent_is_automatically_derived(tcx: TyCtxt<'_>, node: HirId) -> bool {
|
||
let map = &tcx.hir();
|
||
let mut prev_enclosing_node = None;
|
||
let mut enclosing_node = node;
|
||
while Some(enclosing_node) != prev_enclosing_node {
|
||
if is_automatically_derived(map.attrs(enclosing_node)) {
|
||
return true;
|
||
}
|
||
prev_enclosing_node = Some(enclosing_node);
|
||
enclosing_node = map.get_parent_item(enclosing_node);
|
||
}
|
||
false
|
||
}
|
||
|
||
/// Returns true if ty has `iter` or `iter_mut` methods
|
||
pub fn has_iter_method(cx: &LateContext<'_, '_>, probably_ref_ty: Ty<'_>) -> Option<&'static str> {
|
||
// FIXME: instead of this hard-coded list, we should check if `<adt>::iter`
|
||
// exists and has the desired signature. Unfortunately FnCtxt is not exported
|
||
// so we can't use its `lookup_method` method.
|
||
let into_iter_collections: [&[&str]; 13] = [
|
||
&paths::VEC,
|
||
&paths::OPTION,
|
||
&paths::RESULT,
|
||
&paths::BTREESET,
|
||
&paths::BTREEMAP,
|
||
&paths::VEC_DEQUE,
|
||
&paths::LINKED_LIST,
|
||
&paths::BINARY_HEAP,
|
||
&paths::HASHSET,
|
||
&paths::HASHMAP,
|
||
&paths::PATH_BUF,
|
||
&paths::PATH,
|
||
&paths::RECEIVER,
|
||
];
|
||
|
||
let ty_to_check = match probably_ref_ty.kind {
|
||
ty::Ref(_, ty_to_check, _) => ty_to_check,
|
||
_ => probably_ref_ty,
|
||
};
|
||
|
||
let def_id = match ty_to_check.kind {
|
||
ty::Array(..) => return Some("array"),
|
||
ty::Slice(..) => return Some("slice"),
|
||
ty::Adt(adt, _) => adt.did,
|
||
_ => return None,
|
||
};
|
||
|
||
for path in &into_iter_collections {
|
||
if match_def_path(cx, def_id, path) {
|
||
return Some(*path.last().unwrap());
|
||
}
|
||
}
|
||
None
|
||
}
|
||
|
||
/// Matches a function call with the given path and returns the arguments.
|
||
///
|
||
/// Usage:
|
||
///
|
||
/// ```rust,ignore
|
||
/// if let Some(args) = match_function_call(cx, begin_panic_call, &paths::BEGIN_PANIC);
|
||
/// ```
|
||
pub fn match_function_call<'a, 'tcx>(
|
||
cx: &LateContext<'a, 'tcx>,
|
||
expr: &'tcx Expr<'_>,
|
||
path: &[&str],
|
||
) -> Option<&'tcx [Expr<'tcx>]> {
|
||
if_chain! {
|
||
if let ExprKind::Call(ref fun, ref args) = expr.kind;
|
||
if let ExprKind::Path(ref qpath) = fun.kind;
|
||
if let Some(fun_def_id) = cx.tables.qpath_res(qpath, fun.hir_id).opt_def_id();
|
||
if match_def_path(cx, fun_def_id, path);
|
||
then {
|
||
return Some(&args)
|
||
}
|
||
};
|
||
None
|
||
}
|
||
|
||
/// Checks if `Ty` is normalizable. This function is useful
|
||
/// to avoid crashes on `layout_of`.
|
||
pub fn is_normalizable<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, param_env: ty::ParamEnv<'tcx>, ty: Ty<'tcx>) -> bool {
|
||
cx.tcx.infer_ctxt().enter(|infcx| {
|
||
let cause = rustc_middle::traits::ObligationCause::dummy();
|
||
infcx.at(&cause, param_env).normalize(&ty).is_ok()
|
||
})
|
||
}
|
||
|
||
pub fn match_def_path<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, did: DefId, syms: &[&str]) -> bool {
|
||
// We have to convert `syms` to `&[Symbol]` here because rustc's `match_def_path`
|
||
// accepts only that. We should probably move to Symbols in Clippy as well.
|
||
let syms = syms.iter().map(|p| Symbol::intern(p)).collect::<Vec<Symbol>>();
|
||
cx.match_def_path(did, &syms)
|
||
}
|
||
|
||
/// 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 }`.
|
||
pub fn if_sequence<'tcx>(
|
||
mut expr: &'tcx Expr<'tcx>,
|
||
) -> (SmallVec<[&'tcx Expr<'tcx>; 1]>, SmallVec<[&'tcx Block<'tcx>; 1]>) {
|
||
let mut conds = SmallVec::new();
|
||
let mut blocks: SmallVec<[&Block<'_>; 1]> = SmallVec::new();
|
||
|
||
while let Some((ref cond, ref then_expr, ref else_expr)) = higher::if_block(&expr) {
|
||
conds.push(&**cond);
|
||
if let ExprKind::Block(ref block, _) = then_expr.kind {
|
||
blocks.push(block);
|
||
} else {
|
||
panic!("ExprKind::If node is not an ExprKind::Block");
|
||
}
|
||
|
||
if let Some(ref else_expr) = *else_expr {
|
||
expr = else_expr;
|
||
} else {
|
||
break;
|
||
}
|
||
}
|
||
|
||
// final `else {..}`
|
||
if !blocks.is_empty() {
|
||
if let ExprKind::Block(ref block, _) = expr.kind {
|
||
blocks.push(&**block);
|
||
}
|
||
}
|
||
|
||
(conds, blocks)
|
||
}
|
||
|
||
pub fn parent_node_is_if_expr<'a, 'b>(expr: &Expr<'_>, cx: &LateContext<'a, 'b>) -> bool {
|
||
let map = cx.tcx.hir();
|
||
let parent_id = map.get_parent_node(expr.hir_id);
|
||
let parent_node = map.get(parent_id);
|
||
|
||
match parent_node {
|
||
Node::Expr(e) => higher::if_block(&e).is_some(),
|
||
Node::Arm(e) => higher::if_block(&e.body).is_some(),
|
||
_ => false,
|
||
}
|
||
}
|
||
|
||
// Finds the attribute with the given name, if any
|
||
pub fn attr_by_name<'a>(attrs: &'a [Attribute], name: &'_ str) -> Option<&'a Attribute> {
|
||
attrs
|
||
.iter()
|
||
.find(|attr| attr.ident().map_or(false, |ident| ident.as_str() == name))
|
||
}
|
||
|
||
// Finds the `#[must_use]` attribute, if any
|
||
pub fn must_use_attr(attrs: &[Attribute]) -> Option<&Attribute> {
|
||
attr_by_name(attrs, "must_use")
|
||
}
|
||
|
||
// Returns whether the type has #[must_use] attribute
|
||
pub fn is_must_use_ty<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, ty: Ty<'tcx>) -> bool {
|
||
match ty.kind {
|
||
ty::Adt(ref adt, _) => must_use_attr(&cx.tcx.get_attrs(adt.did)).is_some(),
|
||
ty::Foreign(ref did) => must_use_attr(&cx.tcx.get_attrs(*did)).is_some(),
|
||
ty::Slice(ref ty)
|
||
| ty::Array(ref ty, _)
|
||
| ty::RawPtr(ty::TypeAndMut { ref ty, .. })
|
||
| ty::Ref(_, ref ty, _) => {
|
||
// for the Array case we don't need to care for the len == 0 case
|
||
// because we don't want to lint functions returning empty arrays
|
||
is_must_use_ty(cx, *ty)
|
||
},
|
||
ty::Tuple(ref substs) => substs.types().any(|ty| is_must_use_ty(cx, ty)),
|
||
ty::Opaque(ref def_id, _) => {
|
||
for (predicate, _) in cx.tcx.predicates_of(*def_id).predicates {
|
||
if let ty::PredicateKind::Trait(ref poly_trait_predicate, _) = predicate.kind() {
|
||
if must_use_attr(&cx.tcx.get_attrs(poly_trait_predicate.skip_binder().trait_ref.def_id)).is_some() {
|
||
return true;
|
||
}
|
||
}
|
||
}
|
||
false
|
||
},
|
||
ty::Dynamic(binder, _) => {
|
||
for predicate in binder.skip_binder().iter() {
|
||
if let ty::ExistentialPredicate::Trait(ref trait_ref) = predicate {
|
||
if must_use_attr(&cx.tcx.get_attrs(trait_ref.def_id)).is_some() {
|
||
return true;
|
||
}
|
||
}
|
||
}
|
||
false
|
||
},
|
||
_ => false,
|
||
}
|
||
}
|
||
|
||
// check if expr is calling method or function with #[must_use] attribyte
|
||
pub fn is_must_use_func_call(cx: &LateContext<'_, '_>, expr: &Expr<'_>) -> bool {
|
||
let did = match expr.kind {
|
||
ExprKind::Call(ref path, _) => if_chain! {
|
||
if let ExprKind::Path(ref qpath) = path.kind;
|
||
if let def::Res::Def(_, did) = cx.tables.qpath_res(qpath, path.hir_id);
|
||
then {
|
||
Some(did)
|
||
} else {
|
||
None
|
||
}
|
||
},
|
||
ExprKind::MethodCall(_, _, _, _) => cx.tables.type_dependent_def_id(expr.hir_id),
|
||
_ => None,
|
||
};
|
||
|
||
if let Some(did) = did {
|
||
must_use_attr(&cx.tcx.get_attrs(did)).is_some()
|
||
} else {
|
||
false
|
||
}
|
||
}
|
||
|
||
pub fn is_no_std_crate(krate: &Crate<'_>) -> bool {
|
||
krate.item.attrs.iter().any(|attr| {
|
||
if let ast::AttrKind::Normal(ref attr) = attr.kind {
|
||
attr.path == symbol::sym::no_std
|
||
} else {
|
||
false
|
||
}
|
||
})
|
||
}
|
||
|
||
/// Check if parent of a hir node is a trait implementation block.
|
||
/// For example, `f` in
|
||
/// ```rust,ignore
|
||
/// impl Trait for S {
|
||
/// fn f() {}
|
||
/// }
|
||
/// ```
|
||
pub fn is_trait_impl_item(cx: &LateContext<'_, '_>, hir_id: HirId) -> bool {
|
||
if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
|
||
matches!(item.kind, ItemKind::Impl{ of_trait: Some(_), .. })
|
||
} else {
|
||
false
|
||
}
|
||
}
|
||
|
||
/// Check if it's even possible to satisfy the `where` clause for the item.
|
||
///
|
||
/// `trivial_bounds` feature allows functions with unsatisfiable bounds, for example:
|
||
///
|
||
/// ```ignore
|
||
/// fn foo() where i32: Iterator {
|
||
/// for _ in 2i32 {}
|
||
/// }
|
||
/// ```
|
||
pub fn fn_has_unsatisfiable_preds(cx: &LateContext<'_, '_>, did: DefId) -> bool {
|
||
use rustc_trait_selection::traits;
|
||
let predicates =
|
||
cx.tcx
|
||
.predicates_of(did)
|
||
.predicates
|
||
.iter()
|
||
.filter_map(|(p, _)| if p.is_global() { Some(*p) } else { None });
|
||
!traits::normalize_and_test_predicates(
|
||
cx.tcx,
|
||
traits::elaborate_predicates(cx.tcx, predicates)
|
||
.map(|o| o.predicate)
|
||
.collect::<Vec<_>>(),
|
||
)
|
||
}
|
||
|
||
pub fn run_lints(cx: &LateContext<'_, '_>, lints: &[&'static Lint], id: HirId) -> bool {
|
||
lints.iter().any(|lint| {
|
||
matches!(
|
||
cx.tcx.lint_level_at_node(lint, id),
|
||
(Level::Forbid | Level::Deny | Level::Warn, _)
|
||
)
|
||
})
|
||
}
|
||
|
||
#[macro_export]
|
||
macro_rules! unwrap_cargo_metadata {
|
||
($cx: ident, $lint: ident, $deps: expr) => {{
|
||
let mut command = cargo_metadata::MetadataCommand::new();
|
||
if !$deps {
|
||
command.no_deps();
|
||
}
|
||
|
||
match command.exec() {
|
||
Ok(metadata) => metadata,
|
||
Err(err) => {
|
||
span_lint($cx, $lint, DUMMY_SP, &format!("could not read cargo metadata: {}", err));
|
||
return;
|
||
},
|
||
}
|
||
}};
|
||
}
|
||
|
||
#[cfg(test)]
|
||
mod test {
|
||
use super::{trim_multiline, without_block_comments};
|
||
|
||
#[test]
|
||
fn test_trim_multiline_single_line() {
|
||
assert_eq!("", trim_multiline("".into(), false, None));
|
||
assert_eq!("...", trim_multiline("...".into(), false, None));
|
||
assert_eq!("...", trim_multiline(" ...".into(), false, None));
|
||
assert_eq!("...", trim_multiline("\t...".into(), false, None));
|
||
assert_eq!("...", trim_multiline("\t\t...".into(), false, None));
|
||
}
|
||
|
||
#[test]
|
||
#[rustfmt::skip]
|
||
fn test_trim_multiline_block() {
|
||
assert_eq!("\
|
||
if x {
|
||
y
|
||
} else {
|
||
z
|
||
}", trim_multiline(" if x {
|
||
y
|
||
} else {
|
||
z
|
||
}".into(), false, None));
|
||
assert_eq!("\
|
||
if x {
|
||
\ty
|
||
} else {
|
||
\tz
|
||
}", trim_multiline(" if x {
|
||
\ty
|
||
} else {
|
||
\tz
|
||
}".into(), false, None));
|
||
}
|
||
|
||
#[test]
|
||
#[rustfmt::skip]
|
||
fn test_trim_multiline_empty_line() {
|
||
assert_eq!("\
|
||
if x {
|
||
y
|
||
|
||
} else {
|
||
z
|
||
}", trim_multiline(" if x {
|
||
y
|
||
|
||
} else {
|
||
z
|
||
}".into(), false, None));
|
||
}
|
||
|
||
#[test]
|
||
fn test_without_block_comments_lines_without_block_comments() {
|
||
let result = without_block_comments(vec!["/*", "", "*/"]);
|
||
println!("result: {:?}", result);
|
||
assert!(result.is_empty());
|
||
|
||
let result = without_block_comments(vec!["", "/*", "", "*/", "#[crate_type = \"lib\"]", "/*", "", "*/", ""]);
|
||
assert_eq!(result, vec!["", "#[crate_type = \"lib\"]", ""]);
|
||
|
||
let result = without_block_comments(vec!["/* rust", "", "*/"]);
|
||
assert!(result.is_empty());
|
||
|
||
let result = without_block_comments(vec!["/* one-line comment */"]);
|
||
assert!(result.is_empty());
|
||
|
||
let result = without_block_comments(vec!["/* nested", "/* multi-line", "comment", "*/", "test", "*/"]);
|
||
assert!(result.is_empty());
|
||
|
||
let result = without_block_comments(vec!["/* nested /* inline /* comment */ test */ */"]);
|
||
assert!(result.is_empty());
|
||
|
||
let result = without_block_comments(vec!["foo", "bar", "baz"]);
|
||
assert_eq!(result, vec!["foo", "bar", "baz"]);
|
||
}
|
||
}
|