diff options
| author | Philipp Krones <hello@philkrones.com> | 2024-03-21 22:05:29 +0100 |
|---|---|---|
| committer | Philipp Krones <hello@philkrones.com> | 2024-03-21 22:05:29 +0100 |
| commit | 7d42d736c53dce04ec02c2ffdf876d86901de2e7 (patch) | |
| tree | c98b05e5982d9f5726f9e88d411b5662109108d4 /clippy_lints/src | |
| parent | 76096efb48d79ee5d3434d31285828d15a50b9c7 (diff) | |
| parent | 443f459f98841001b2c2041adda05b9318f44b24 (diff) | |
Merge remote-tracking branch 'upstream/master' into rustup
Diffstat (limited to 'clippy_lints/src')
51 files changed, 1300 insertions, 346 deletions
diff --git a/clippy_lints/src/assigning_clones.rs b/clippy_lints/src/assigning_clones.rs index b1c552c7a8d..88d9f762a87 100644 --- a/clippy_lints/src/assigning_clones.rs +++ b/clippy_lints/src/assigning_clones.rs @@ -1,3 +1,4 @@ +use clippy_config::msrvs::{self, Msrv}; use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::macros::HirNode; use clippy_utils::sugg::Sugg; @@ -6,7 +7,7 @@ use rustc_errors::Applicability; use rustc_hir::{self as hir, Expr, ExprKind, Node}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::ty::{self, Instance, Mutability}; -use rustc_session::declare_lint_pass; +use rustc_session::impl_lint_pass; use rustc_span::def_id::DefId; use rustc_span::symbol::sym; use rustc_span::ExpnKind; @@ -49,7 +50,19 @@ declare_clippy_lint! { perf, "assigning the result of cloning may be inefficient" } -declare_lint_pass!(AssigningClones => [ASSIGNING_CLONES]); + +pub struct AssigningClones { + msrv: Msrv, +} + +impl AssigningClones { + #[must_use] + pub fn new(msrv: Msrv) -> Self { + Self { msrv } + } +} + +impl_lint_pass!(AssigningClones => [ASSIGNING_CLONES]); impl<'tcx> LateLintPass<'tcx> for AssigningClones { fn check_expr(&mut self, cx: &LateContext<'tcx>, assign_expr: &'tcx hir::Expr<'_>) { @@ -68,10 +81,12 @@ impl<'tcx> LateLintPass<'tcx> for AssigningClones { return; }; - if is_ok_to_suggest(cx, lhs, &call) { + if is_ok_to_suggest(cx, lhs, &call, &self.msrv) { suggest(cx, assign_expr, lhs, &call); } } + + extract_msrv_attr!(LateContext); } // Try to resolve the call to `Clone::clone` or `ToOwned::to_owned`. @@ -135,7 +150,13 @@ fn extract_call<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> Option< // Return true if we find that the called method has a custom implementation and isn't derived or // provided by default by the corresponding trait. -fn is_ok_to_suggest<'tcx>(cx: &LateContext<'tcx>, lhs: &Expr<'tcx>, call: &CallCandidate<'tcx>) -> bool { +fn is_ok_to_suggest<'tcx>(cx: &LateContext<'tcx>, lhs: &Expr<'tcx>, call: &CallCandidate<'tcx>, msrv: &Msrv) -> bool { + // For calls to .to_owned we suggest using .clone_into(), which was only stablilized in 1.63. + // If the current MSRV is below that, don't suggest the lint. + if !msrv.meets(msrvs::ASSIGNING_CLONES) && matches!(call.target, TargetTrait::ToOwned) { + return false; + } + // If the left-hand side is a local variable, it might be uninitialized at this point. // In that case we do not want to suggest the lint. if let Some(local) = path_to_local(lhs) { diff --git a/clippy_lints/src/attrs/duplicated_attributes.rs b/clippy_lints/src/attrs/duplicated_attributes.rs new file mode 100644 index 00000000000..3c5ac597fd5 --- /dev/null +++ b/clippy_lints/src/attrs/duplicated_attributes.rs @@ -0,0 +1,64 @@ +use super::DUPLICATED_ATTRIBUTES; +use clippy_utils::diagnostics::span_lint_and_then; +use rustc_ast::{Attribute, MetaItem}; +use rustc_data_structures::fx::FxHashMap; +use rustc_lint::EarlyContext; +use rustc_span::{sym, Span}; +use std::collections::hash_map::Entry; + +fn emit_if_duplicated( + cx: &EarlyContext<'_>, + attr: &MetaItem, + attr_paths: &mut FxHashMap<String, Span>, + complete_path: String, +) { + match attr_paths.entry(complete_path) { + Entry::Vacant(v) => { + v.insert(attr.span); + }, + Entry::Occupied(o) => { + span_lint_and_then(cx, DUPLICATED_ATTRIBUTES, attr.span, "duplicated attribute", |diag| { + diag.span_note(*o.get(), "first defined here"); + diag.span_help(attr.span, "remove this attribute"); + }); + }, + } +} + +fn check_duplicated_attr( + cx: &EarlyContext<'_>, + attr: &MetaItem, + attr_paths: &mut FxHashMap<String, Span>, + parent: &mut Vec<String>, +) { + let Some(ident) = attr.ident() else { return }; + let name = ident.name; + if name == sym::doc || name == sym::cfg_attr { + // FIXME: Would be nice to handle `cfg_attr` as well. Only problem is to check that cfg + // conditions are the same. + return; + } + if let Some(value) = attr.value_str() { + emit_if_duplicated(cx, attr, attr_paths, format!("{}:{name}={value}", parent.join(":"))); + } else if let Some(sub_attrs) = attr.meta_item_list() { + parent.push(name.as_str().to_string()); + for sub_attr in sub_attrs { + if let Some(meta) = sub_attr.meta_item() { + check_duplicated_attr(cx, meta, attr_paths, parent); + } + } + parent.pop(); + } else { + emit_if_duplicated(cx, attr, attr_paths, format!("{}:{name}", parent.join(":"))); + } +} + +pub fn check(cx: &EarlyContext<'_>, attrs: &[Attribute]) { + let mut attr_paths = FxHashMap::default(); + + for attr in attrs { + if let Some(meta) = attr.meta() { + check_duplicated_attr(cx, &meta, &mut attr_paths, &mut Vec::new()); + } + } +} diff --git a/clippy_lints/src/attrs/mod.rs b/clippy_lints/src/attrs/mod.rs index c4c65d3248a..675c428948f 100644 --- a/clippy_lints/src/attrs/mod.rs +++ b/clippy_lints/src/attrs/mod.rs @@ -4,6 +4,7 @@ mod allow_attributes_without_reason; mod blanket_clippy_restriction_lints; mod deprecated_cfg_attr; mod deprecated_semver; +mod duplicated_attributes; mod empty_line_after; mod inline_always; mod maybe_misused_cfg; @@ -16,7 +17,7 @@ mod useless_attribute; mod utils; use clippy_config::msrvs::Msrv; -use rustc_ast::{Attribute, MetaItemKind, NestedMetaItem}; +use rustc_ast::{Attribute, Crate, MetaItemKind, NestedMetaItem}; use rustc_hir::{ImplItem, Item, ItemKind, TraitItem}; use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass}; use rustc_session::{declare_lint_pass, impl_lint_pass}; @@ -489,6 +490,32 @@ declare_clippy_lint! { "item has both inner and outer attributes" } +declare_clippy_lint! { + /// ### What it does + /// Checks for attributes that appear two or more times. + /// + /// ### Why is this bad? + /// Repeating an attribute on the same item (or globally on the same crate) + /// is unnecessary and doesn't have an effect. + /// + /// ### Example + /// ```no_run + /// #[allow(dead_code)] + /// #[allow(dead_code)] + /// fn foo() {} + /// ``` + /// + /// Use instead: + /// ```no_run + /// #[allow(dead_code)] + /// fn foo() {} + /// ``` + #[clippy::version = "1.78.0"] + pub DUPLICATED_ATTRIBUTES, + suspicious, + "duplicated attribute" +} + declare_lint_pass!(Attributes => [ ALLOW_ATTRIBUTES_WITHOUT_REASON, INLINE_ALWAYS, @@ -568,12 +595,18 @@ impl_lint_pass!(EarlyAttributes => [ DEPRECATED_CLIPPY_CFG_ATTR, UNNECESSARY_CLIPPY_CFG, MIXED_ATTRIBUTES_STYLE, + DUPLICATED_ATTRIBUTES, ]); impl EarlyLintPass for EarlyAttributes { + fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) { + duplicated_attributes::check(cx, &krate.attrs); + } + fn check_item(&mut self, cx: &EarlyContext<'_>, item: &rustc_ast::Item) { empty_line_after::check(cx, item); mixed_attributes_style::check(cx, item); + duplicated_attributes::check(cx, &item.attrs); } fn check_attribute(&mut self, cx: &EarlyContext<'_>, attr: &Attribute) { diff --git a/clippy_lints/src/casts/cast_lossless.rs b/clippy_lints/src/casts/cast_lossless.rs index fe2455f4b23..86f4332d05a 100644 --- a/clippy_lints/src/casts/cast_lossless.rs +++ b/clippy_lints/src/casts/cast_lossless.rs @@ -1,12 +1,12 @@ use clippy_config::msrvs::{self, Msrv}; use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::in_constant; -use clippy_utils::source::snippet_opt; +use clippy_utils::source::{snippet_opt, snippet_with_applicability}; use clippy_utils::ty::is_isize_or_usize; use rustc_errors::Applicability; -use rustc_hir::{Expr, ExprKind}; +use rustc_hir::{Expr, ExprKind, QPath, TyKind}; use rustc_lint::LateContext; -use rustc_middle::ty::{self, FloatTy, Ty}; +use rustc_middle::ty::{self, FloatTy, Ty, UintTy}; use super::{utils, CAST_LOSSLESS}; @@ -16,6 +16,7 @@ pub(super) fn check( cast_op: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>, + cast_to_hir: &rustc_hir::Ty<'_>, msrv: &Msrv, ) { if !should_lint(cx, expr, cast_from, cast_to, msrv) { @@ -24,11 +25,11 @@ pub(super) fn check( // The suggestion is to use a function call, so if the original expression // has parens on the outside, they are no longer needed. - let mut applicability = Applicability::MachineApplicable; + let mut app = Applicability::MachineApplicable; let opt = snippet_opt(cx, cast_op.span.source_callsite()); let sugg = opt.as_ref().map_or_else( || { - applicability = Applicability::HasPlaceholders; + app = Applicability::HasPlaceholders; ".." }, |snip| { @@ -40,10 +41,27 @@ pub(super) fn check( }, ); + // Display the type alias instead of the aliased type. Fixes #11285 + // + // FIXME: Once `lazy_type_alias` is stabilized(?) we should use `rustc_middle` types instead, + // this will allow us to display the right type with `cast_from` as well. + let cast_to_fmt = if let TyKind::Path(QPath::Resolved(None, path)) = cast_to_hir.kind + // It's a bit annoying but the turbofish is optional for types. A type in an `as` cast + // shouldn't have these if they're primitives, which are the only things we deal with. + // + // This could be removed for performance if this check is determined to have a pretty major + // effect. + && path.segments.iter().all(|segment| segment.args.is_none()) + { + snippet_with_applicability(cx, cast_to_hir.span, "..", &mut app) + } else { + cast_to.to_string().into() + }; + let message = if cast_from.is_bool() { - format!("casting `{cast_from:}` to `{cast_to:}` is more cleanly stated with `{cast_to:}::from(_)`") + format!("casting `{cast_from}` to `{cast_to_fmt}` is more cleanly stated with `{cast_to_fmt}::from(_)`") } else { - format!("casting `{cast_from}` to `{cast_to}` may become silently lossy if you later change the type") + format!("casting `{cast_from}` to `{cast_to_fmt}` may become silently lossy if you later change the type") }; span_lint_and_sugg( @@ -52,14 +70,17 @@ pub(super) fn check( expr.span, &message, "try", - format!("{cast_to}::from({sugg})"), - applicability, + format!("{cast_to_fmt}::from({sugg})"), + app, ); } fn should_lint(cx: &LateContext<'_>, expr: &Expr<'_>, cast_from: Ty<'_>, cast_to: Ty<'_>, msrv: &Msrv) -> bool { // Do not suggest using From in consts/statics until it is valid to do so (see #2267). - if in_constant(cx, expr.hir_id) { + // + // If destination is u128, do not lint because source type cannot be larger + // If source is bool, still lint due to the lint message differing (refers to style) + if in_constant(cx, expr.hir_id) || (!cast_from.is_bool() && matches!(cast_to.kind(), ty::Uint(UintTy::U128))) { return false; } diff --git a/clippy_lints/src/casts/mod.rs b/clippy_lints/src/casts/mod.rs index 14f2f4a7f59..063aab28238 100644 --- a/clippy_lints/src/casts/mod.rs +++ b/clippy_lints/src/casts/mod.rs @@ -791,7 +791,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts { cast_abs_to_unsigned::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv); cast_nan_to_int::check(cx, expr, cast_expr, cast_from, cast_to); } - cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, &self.msrv); + cast_lossless::check(cx, expr, cast_expr, cast_from, cast_to, cast_to_hir, &self.msrv); cast_enum_constructor::check(cx, expr, cast_expr, cast_from); } diff --git a/clippy_lints/src/dbg_macro.rs b/clippy_lints/src/dbg_macro.rs index ec66556cebf..e2296767431 100644 --- a/clippy_lints/src/dbg_macro.rs +++ b/clippy_lints/src/dbg_macro.rs @@ -1,12 +1,14 @@ use clippy_utils::diagnostics::span_lint_and_sugg; -use clippy_utils::macros::root_macro_call_first_node; +use clippy_utils::macros::{macro_backtrace, MacroCall}; use clippy_utils::source::snippet_with_applicability; use clippy_utils::{is_in_cfg_test, is_in_test_function}; +use rustc_data_structures::fx::FxHashSet; use rustc_errors::Applicability; -use rustc_hir::{Expr, ExprKind, Node}; +use rustc_hir::{Expr, ExprKind, HirId, Node}; use rustc_lint::{LateContext, LateLintPass, LintContext}; +use rustc_middle::lint::in_external_macro; use rustc_session::impl_lint_pass; -use rustc_span::sym; +use rustc_span::{sym, Span, SyntaxContext}; declare_clippy_lint! { /// ### What it does @@ -31,31 +33,38 @@ declare_clippy_lint! { "`dbg!` macro is intended as a debugging tool" } -#[derive(Copy, Clone)] +#[derive(Clone)] pub struct DbgMacro { allow_dbg_in_tests: bool, + /// Tracks the `dbg!` macro callsites that are already checked. + checked_dbg_call_site: FxHashSet<Span>, + /// Tracks the previous `SyntaxContext`, to avoid walking the same context chain. + prev_ctxt: SyntaxContext, } impl_lint_pass!(DbgMacro => [DBG_MACRO]); impl DbgMacro { pub fn new(allow_dbg_in_tests: bool) -> Self { - DbgMacro { allow_dbg_in_tests } + DbgMacro { + allow_dbg_in_tests, + checked_dbg_call_site: FxHashSet::default(), + prev_ctxt: SyntaxContext::root(), + } } } impl LateLintPass<'_> for DbgMacro { fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { - let Some(macro_call) = root_macro_call_first_node(cx, expr) else { - return; - }; - if cx.tcx.is_diagnostic_item(sym::dbg_macro, macro_call.def_id) { + let cur_syntax_ctxt = expr.span.ctxt(); + + if cur_syntax_ctxt != self.prev_ctxt && + let Some(macro_call) = first_dbg_macro_in_expansion(cx, expr.span) && + !in_external_macro(cx.sess(), macro_call.span) && + self.checked_dbg_call_site.insert(macro_call.span) && // allows `dbg!` in test code if allow-dbg-in-test is set to true in clippy.toml - if self.allow_dbg_in_tests - && (is_in_test_function(cx.tcx, expr.hir_id) || is_in_cfg_test(cx.tcx, expr.hir_id)) - { - return; - } + !(self.allow_dbg_in_tests && is_in_test(cx, expr.hir_id)) + { let mut applicability = Applicability::MachineApplicable; let (sugg_span, suggestion) = match expr.peel_drop_temps().kind { @@ -101,6 +110,8 @@ impl LateLintPass<'_> for DbgMacro { _ => return, }; + self.prev_ctxt = cur_syntax_ctxt; + span_lint_and_sugg( cx, DBG_MACRO, @@ -112,4 +123,16 @@ impl LateLintPass<'_> for DbgMacro { ); } } + + fn check_crate_post(&mut self, _: &LateContext<'_>) { + self.checked_dbg_call_site = FxHashSet::default(); + } +} + +fn is_in_test(cx: &LateContext<'_>, hir_id: HirId) -> bool { + is_in_test_function(cx.tcx, hir_id) || is_in_cfg_test(cx.tcx, hir_id) +} + +fn first_dbg_macro_in_expansion(cx: &LateContext<'_>, span: Span) -> Option<MacroCall> { + macro_backtrace(span).find(|mc| cx.tcx.is_diagnostic_item(sym::dbg_macro, mc.def_id)) } diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index 2b324f5f96e..c8e148598a2 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -54,6 +54,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::attrs::DEPRECATED_CFG_ATTR_INFO, crate::attrs::DEPRECATED_CLIPPY_CFG_ATTR_INFO, crate::attrs::DEPRECATED_SEMVER_INFO, + crate::attrs::DUPLICATED_ATTRIBUTES_INFO, crate::attrs::EMPTY_LINE_AFTER_DOC_COMMENTS_INFO, crate::attrs::EMPTY_LINE_AFTER_OUTER_ATTR_INFO, crate::attrs::INLINE_ALWAYS_INFO, @@ -235,6 +236,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::instant_subtraction::MANUAL_INSTANT_ELAPSED_INFO, crate::instant_subtraction::UNCHECKED_DURATION_SUBTRACTION_INFO, crate::int_plus_one::INT_PLUS_ONE_INFO, + crate::integer_division_remainder_used::INTEGER_DIVISION_REMAINDER_USED_INFO, crate::invalid_upcast_comparisons::INVALID_UPCAST_COMPARISONS_INFO, crate::item_name_repetitions::ENUM_VARIANT_NAMES_INFO, crate::item_name_repetitions::MODULE_INCEPTION_INFO, @@ -310,6 +312,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::manual_slice_size_calculation::MANUAL_SLICE_SIZE_CALCULATION_INFO, crate::manual_string_new::MANUAL_STRING_NEW_INFO, crate::manual_strip::MANUAL_STRIP_INFO, + crate::manual_unwrap_or_default::MANUAL_UNWRAP_OR_DEFAULT_INFO, crate::map_unit_fn::OPTION_MAP_UNIT_FN_INFO, crate::map_unit_fn::RESULT_MAP_UNIT_FN_INFO, crate::match_result_ok::MATCH_RESULT_OK_INFO, @@ -353,6 +356,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::methods::CLONE_ON_COPY_INFO, crate::methods::CLONE_ON_REF_PTR_INFO, crate::methods::COLLAPSIBLE_STR_REPLACE_INFO, + crate::methods::CONST_IS_EMPTY_INFO, crate::methods::DRAIN_COLLECT_INFO, crate::methods::ERR_EXPECT_INFO, crate::methods::EXPECT_FUN_CALL_INFO, @@ -750,5 +754,6 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::write::WRITE_LITERAL_INFO, crate::write::WRITE_WITH_NEWLINE_INFO, crate::zero_div_zero::ZERO_DIVIDED_BY_ZERO_INFO, + crate::zero_repeat_side_effects::ZERO_REPEAT_SIDE_EFFECTS_INFO, crate::zero_sized_map_values::ZERO_SIZED_MAP_VALUES_INFO, ]; diff --git a/clippy_lints/src/doc/markdown.rs b/clippy_lints/src/doc/markdown.rs index d2f14756591..1add02af310 100644 --- a/clippy_lints/src/doc/markdown.rs +++ b/clippy_lints/src/doc/markdown.rs @@ -8,7 +8,14 @@ use url::Url; use crate::doc::DOC_MARKDOWN; -pub fn check(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, text: &str, span: Span, code_level: isize) { +pub fn check( + cx: &LateContext<'_>, + valid_idents: &FxHashSet<String>, + text: &str, + span: Span, + code_level: isize, + blockquote_level: isize, +) { for orig_word in text.split(|c: char| c.is_whitespace() || c == '\'') { // Trim punctuation as in `some comment (see foo::bar).` // ^^ @@ -46,11 +53,11 @@ pub fn check(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, text: &str, span.parent(), ); - check_word(cx, word, span, code_level); + check_word(cx, word, span, code_level, blockquote_level); } } -fn check_word(cx: &LateContext<'_>, word: &str, span: Span, code_level: isize) { +fn check_word(cx: &LateContext<'_>, word: &str, span: Span, code_level: isize, blockquote_level: isize) { /// Checks if a string is upper-camel-case, i.e., starts with an uppercase and /// contains at least two uppercase letters (`Clippy` is ok) and one lower-case /// letter (`NASA` is ok). @@ -97,7 +104,9 @@ fn check_word(cx: &LateContext<'_>, word: &str, span: Span, code_level: isize) { } // We assume that mixed-case words are not meant to be put inside backticks. (Issue #2343) - if code_level > 0 || (has_underscore(word) && has_hyphen(word)) { + // + // We also assume that backticks are not necessary if inside a quote. (Issue #10262) + if code_level > 0 || blockquote_level > 0 || (has_underscore(word) && has_hyphen(word)) { return; } diff --git a/clippy_lints/src/doc/mod.rs b/clippy_lints/src/doc/mod.rs index 003d26b7b89..b135e4e3577 100644 --- a/clippy_lints/src/doc/mod.rs +++ b/clippy_lints/src/doc/mod.rs @@ -7,14 +7,14 @@ use clippy_utils::{is_entrypoint_fn, method_chain_args}; use pulldown_cmark::Event::{ Code, End, FootnoteReference, HardBreak, Html, Rule, SoftBreak, Start, TaskListMarker, Text, }; -use pulldown_cmark::Tag::{CodeBlock, Heading, Item, Link, Paragraph}; +use pulldown_cmark::Tag::{BlockQuote, CodeBlock, Heading, Item, Link, Paragraph}; use pulldown_cmark::{BrokenLink, CodeBlockKind, CowStr, Options}; use rustc_ast::ast::Attribute; use rustc_data_structures::fx::FxHashSet; use rustc_hir as hir; use rustc_hir::intravisit::{self, Visitor}; use rustc_hir::{AnonConst, Expr}; -use rustc_lint::{LateContext, LateLintPass}; +use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::nested_filter; use rustc_middle::lint::in_external_macro; use rustc_middle::ty; @@ -538,7 +538,16 @@ fn check_attrs(cx: &LateContext<'_>, valid_idents: &FxHashSet<String>, attrs: &[ suspicious_doc_comments::check(cx, attrs); - let (fragments, _) = attrs_to_doc_fragments(attrs.iter().map(|attr| (attr, None)), true); + let (fragments, _) = attrs_to_doc_fragments( + attrs.iter().filter_map(|attr| { + if in_external_macro(cx.sess(), attr.span) { + None + } else { + Some((attr, None)) + } + }), + true, + ); let mut doc = fragments.iter().fold(String::new(), |mut acc, fragment| { add_doc_fragment(&mut acc, fragment); acc @@ -602,6 +611,7 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize let mut text_to_check: Vec<(CowStr<'_>, Range<usize>, isize)> = Vec::new(); let mut paragraph_range = 0..0; let mut code_level = 0; + let mut blockquote_level = 0; for (event, range) in events { match event { @@ -610,8 +620,14 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize code_level += 1; } else if tag.starts_with("</code") { code_level -= 1; + } else if tag.starts_with("<blockquote") || tag.starts_with("<q") { + blockquote_level += 1; + } else if tag.starts_with("</blockquote") || tag.starts_with("</q") { + blockquote_level -= 1; } }, + Start(BlockQuote) => blockquote_level += 1, + End(BlockQuote) => blockquote_level -= 1, Start(CodeBlock(ref kind)) => { in_code = true; if let CodeBlockKind::Fenced(lang) = kind { @@ -663,7 +679,7 @@ fn check_doc<'a, Events: Iterator<Item = (pulldown_cmark::Event<'a>, Range<usize } else { for (text, range, assoc_code_level) in text_to_check { if let Some(span) = fragments.span(cx, range) { - markdown::check(cx, valid_idents, &text, span, assoc_code_level); + markdown::check(cx, valid_idents, &text, span, assoc_code_level, blockquote_level); } } } diff --git a/clippy_lints/src/else_if_without_else.rs b/clippy_lints/src/else_if_without_else.rs index 47780cab9ed..a6ca7fe9e0b 100644 --- a/clippy_lints/src/else_if_without_else.rs +++ b/clippy_lints/src/else_if_without_else.rs @@ -49,24 +49,22 @@ declare_clippy_lint! { declare_lint_pass!(ElseIfWithoutElse => [ELSE_IF_WITHOUT_ELSE]); impl EarlyLintPass for ElseIfWithoutElse { - fn check_expr(&mut self, cx: &EarlyContext<'_>, mut item: &Expr) { + fn check_expr(&mut self, cx: &EarlyContext<'_>, item: &Expr) { if in_external_macro(cx.sess(), item.span) { return; } - while let ExprKind::If(_, _, Some(ref els)) = item.kind { - if let ExprKind::If(_, _, None) = els.kind { - span_lint_and_help( - cx, - ELSE_IF_WITHOUT_ELSE, - els.span, - "`if` expression with an `else if`, but without a final `else`", - None, - "add an `else` block here", - ); - } - - item = els; + if let ExprKind::If(_, _, Some(ref els)) = item.kind + && let ExprKind::If(_, _, None) = els.kind + { + span_lint_and_help( + cx, + ELSE_IF_WITHOUT_ELSE, + els.span, + "`if` expression with an `else if`, but without a final `else`", + None, + "add an `else` block here", + ); } } } diff --git a/clippy_lints/src/entry.rs b/clippy_lints/src/entry.rs index ebda2ad8387..dafbf6c8846 100644 --- a/clippy_lints/src/entry.rs +++ b/clippy_lints/src/entry.rs @@ -358,7 +358,7 @@ struct InsertSearcher<'cx, 'tcx> { can_use_entry: bool, /// Whether this expression is the final expression in this code path. This may be a statement. in_tail_pos: bool, - // Is this expression a single insert. A slightly better suggestion can be made in this case. + /// Is this expression a single insert. A slightly better suggestion can be made in this case. is_single_insert: bool, /// If the visitor has seen the map being used. is_map_used: bool, @@ -431,6 +431,9 @@ impl<'tcx> Visitor<'tcx> for InsertSearcher<'_, 'tcx> { self.is_single_insert = false; self.visit_expr(e); } + if let Some(els) = &l.els { + self.visit_block(els); + } }, StmtKind::Item(_) => { self.allow_insert_closure &= !self.in_tail_pos; diff --git a/clippy_lints/src/from_over_into.rs b/clippy_lints/src/from_over_into.rs index 1933a00891b..93527bcdf5c 100644 --- a/clippy_lints/src/from_over_into.rs +++ b/clippy_lints/src/from_over_into.rs @@ -181,6 +181,9 @@ fn convert_to_from( let from = snippet_opt(cx, self_ty.span)?; let into = snippet_opt(cx, target_ty.span)?; + let return_type = matches!(sig.decl.output, FnRetTy::Return(_)) + .then_some(String::from("Self")) + .unwrap_or_default(); let mut suggestions = vec![ // impl Into<T> for U -> impl From<T> for U // ~~~~ ~~~~ @@ -197,13 +200,10 @@ fn convert_to_from( // fn into([mut] self) -> T -> fn into([mut] v: T) -> T // ~~~~ ~~~~ (self_ident.span, format!("val: {from}")), - ]; - - if let FnRetTy::Return(_) = sig.decl.output { // fn into(self) -> T -> fn into(self) -> Self // ~ ~~~~ - suggestions.push((sig.decl.output.span(), String::from("Self"))); - } + (sig.decl.output.span(), return_type), + ]; let mut finder = SelfFinder { cx, diff --git a/clippy_lints/src/functions/mod.rs b/clippy_lints/src/functions/mod.rs index 96da2ec2a1a..9cc51fa8cd5 100644 --- a/clippy_lints/src/functions/mod.rs +++ b/clippy_lints/src/functions/mod.rs @@ -250,7 +250,7 @@ declare_clippy_lint! { /// /// ### Why is this bad? /// A `Result` is at least as large as the `Err`-variant. While we - /// expect that variant to be seldomly used, the compiler needs to reserve + /// expect that variant to be seldom used, the compiler needs to reserve /// and move that much memory every single time. /// Furthermore, errors are often simply passed up the call-stack, making /// use of the `?`-operator and its type-conversion mechanics. If the diff --git a/clippy_lints/src/integer_division_remainder_used.rs b/clippy_lints/src/integer_division_remainder_used.rs new file mode 100644 index 00000000000..36dc45ca788 --- /dev/null +++ b/clippy_lints/src/integer_division_remainder_used.rs @@ -0,0 +1,50 @@ +use clippy_utils::diagnostics::span_lint; +use rustc_ast::BinOpKind; +use rustc_hir::{Expr, ExprKind}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::ty::{self}; +use rustc_session::declare_lint_pass; + +declare_clippy_lint! { + /// ### What it does + /// Checks for the usage of division (/) and remainder (%) operations + /// when performed on any integer types using the default Div and Rem trait implementations. + /// + /// ### Why is this bad? + /// In cryptographic contexts, division can result in timing sidechannel vulnerabilities, + /// and needs to be replaced with constant-time code instead (e.g. Barrett reduction). + /// + /// ### Example + /// ```no_run + /// let my_div = 10 / 2; + /// ``` + /// Use instead: + /// ```no_run + /// let my_div = 10 >> 1; + /// ``` + #[clippy::version = "1.78.0"] + pub INTEGER_DIVISION_REMAINDER_USED, + restriction, + "use of disallowed default division and remainder operations" +} + +declare_lint_pass!(IntegerDivisionRemainderUsed => [INTEGER_DIVISION_REMAINDER_USED]); + +impl LateLintPass<'_> for IntegerDivisionRemainderUsed { + fn check_expr(&mut self, cx: &LateContext<'_>, expr: &Expr<'_>) { + if let ExprKind::Binary(op, lhs, rhs) = &expr.kind + && let BinOpKind::Div | BinOpKind::Rem = op.node + && let lhs_ty = cx.typeck_results().expr_ty(lhs) + && let rhs_ty = cx.typeck_results().expr_ty(rhs) + && let ty::Int(_) | ty::Uint(_) = lhs_ty.peel_refs().kind() + && let ty::Int(_) | ty::Uint(_) = rhs_ty.peel_refs().kind() + { + span_lint( + cx, + INTEGER_DIVISION_REMAINDER_USED, + expr.span.source_callsite(), + &format!("use of {} has been disallowed in this context", op.node.as_str()), + ); + } + } +} diff --git a/clippy_lints/src/let_if_seq.rs b/clippy_lints/src/let_if_seq.rs index f084d89ccc2..d4ddf76fb8a 100644 --- a/clippy_lints/src/let_if_seq.rs +++ b/clippy_lints/src/let_if_seq.rs @@ -1,4 +1,4 @@ -use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::diagnostics::span_lint_hir_and_then; use clippy_utils::path_to_local_id; use clippy_utils::source::snippet; use clippy_utils::visitors::is_local_used; @@ -122,9 +122,10 @@ impl<'tcx> LateLintPass<'tcx> for LetIfSeq { value=snippet(cx, value.span, "<value>"), default=snippet(cx, default.span, "<default>"), ); - span_lint_and_then( + span_lint_hir_and_then( cx, USELESS_LET_IF_SEQ, + local.hir_id, span, "`if _ { .. } else { .. }` is an expression", |diag| { diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index b930175c4d8..57fac351042 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -172,6 +172,7 @@ mod init_numbered_fields; mod inline_fn_without_body; mod instant_subtraction; mod int_plus_one; +mod integer_division_remainder_used; mod invalid_upcast_comparisons; mod item_name_repetitions; mod items_after_statements; @@ -211,6 +212,7 @@ mod manual_retain; mod manual_slice_size_calculation; mod manual_string_new; mod manual_strip; +mod manual_unwrap_or_default; mod map_unit_fn; mod match_result_ok; mod matches; @@ -373,6 +375,7 @@ mod visibility; mod wildcard_imports; mod write; mod zero_div_zero; +mod zero_repeat_side_effects; mod zero_sized_map_values; // end lints modules, do not remove this comment, it’s used in `update_lints` @@ -1119,7 +1122,10 @@ pub fn register_lints(store: &mut rustc_lint::LintStore, conf: &'static Conf) { store.register_late_pass(move |_| Box::new(incompatible_msrv::IncompatibleMsrv::new(msrv()))); store.register_late_pass(|_| Box::new(to_string_trait_impl::ToStringTraitImpl)); store.register_early_pass(|| Box::new(multiple_bound_locations::MultipleBoundLocations)); - store.register_late_pass(|_| Box::new(assigning_clones::AssigningClones)); + store.register_late_pass(move |_| Box::new(assigning_clones::AssigningClones::new(msrv()))); + store.register_late_pass(|_| Box::new(zero_repeat_side_effects::ZeroRepeatSideEffects)); + store.register_late_pass(|_| Box::new(manual_unwrap_or_default::ManualUnwrapOrDefault)); + store.register_late_pass(|_| Box::new(integer_division_remainder_used::IntegerDivisionRemainderUsed)); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/loops/needless_range_loop.rs b/clippy_lints/src/loops/needless_range_loop.rs index 47dc3807e62..cf34c904dfe 100644 --- a/clippy_lints/src/loops/needless_range_loop.rs +++ b/clippy_lints/src/loops/needless_range_loop.rs @@ -273,7 +273,7 @@ impl<'a, 'tcx> VarVisitor<'a, 'tcx> { } return false; // no need to walk further *on the variable* }, - Res::Def(DefKind::Static{..} | DefKind::Const, ..) => { + Res::Def(DefKind::Static { .. } | DefKind::Const, ..) => { if index_used_directly { self.indexed_directly.insert( seqvar.segments[0].ident.name, diff --git a/clippy_lints/src/loops/never_loop.rs b/clippy_lints/src/loops/never_loop.rs index 6cc79440f39..8aae7be4593 100644 --- a/clippy_lints/src/loops/never_loop.rs +++ b/clippy_lints/src/loops/never_loop.rs @@ -255,9 +255,7 @@ fn never_loop_expr<'tcx>( InlineAsmOperand::Const { .. } | InlineAsmOperand::SymFn { .. } | InlineAsmOperand::SymStatic { .. } => { NeverLoopResult::Normal }, - InlineAsmOperand::Label { block } => { - never_loop_block(cx, block, local_labels, main_loop_id) - } + InlineAsmOperand::Label { block } => never_loop_block(cx, block, local_labels, main_loop_id), })), ExprKind::OffsetOf(_, _) | ExprKind::Yield(_, _) diff --git a/clippy_lints/src/loops/unused_enumerate_index.rs b/clippy_lints/src/loops/unused_enumerate_index.rs index dd7fae79d9b..31f0f1cfeba 100644 --- a/clippy_lints/src/loops/unused_enumerate_index.rs +++ b/clippy_lints/src/loops/unused_enumerate_index.rs @@ -1,62 +1,41 @@ use super::UNUSED_ENUMERATE_INDEX; use clippy_utils::diagnostics::{multispan_sugg, span_lint_and_then}; use clippy_utils::source::snippet; -use clippy_utils::{pat_is_wild, sugg}; +use clippy_utils::{match_def_path, pat_is_wild, sugg}; use rustc_hir::def::DefKind; use rustc_hir::{Expr, ExprKind, Pat, PatKind}; use rustc_lint::LateContext; use rustc_middle::ty; /// Checks for the `UNUSED_ENUMERATE_INDEX` lint. -pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &'tcx Pat<'_>, arg: &'tcx Expr<'_>, body: &'tcx Expr<'_>) { - let PatKind::Tuple([index, elem], _) = pat.kind else { - return; - }; - - let ExprKind::MethodCall(_method, self_arg, [], _) = arg.kind else { - return; - }; - - let ty = cx.typeck_results().expr_ty(arg); - - if !pat_is_wild(cx, &index.kind, body) { - return; - } - - let name = match *ty.kind() { - ty::Adt(base, _substs) => cx.tcx.def_path_str(base.did()), - _ => return, - }; - - if name != "std::iter::Enumerate" && name != "core::iter::Enumerate" { - return; +/// +/// The lint is also partially implemented in `clippy_lints/src/methods/unused_enumerate_index.rs`. +pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>, arg: &Expr<'_>, body: &'tcx Expr<'tcx>) { + if let PatKind::Tuple([index, elem], _) = pat.kind + && let ExprKind::MethodCall(_method, self_arg, [], _) = arg.kind + && let ty = cx.typeck_results().expr_ty(arg) + && pat_is_wild(cx, &index.kind, body) + && let ty::Adt(base, _) = *ty.kind() + && match_def_path(cx, base.did(), &clippy_utils::paths::CORE_ITER_ENUMERATE_STRUCT) + && let Some((DefKind::AssocFn, call_id)) = cx.typeck_results().type_dependent_def(arg.hir_id) + && match_def_path(cx, call_id, &clippy_utils::paths::CORE_ITER_ENUMERATE_METHOD) + { + span_lint_and_then( + cx, + UNUSED_ENUMERATE_INDEX, + arg.span, + "you seem to use `.enumerate()` and immediately discard the index", + |diag| { + let base_iter = sugg::Sugg::hir(cx, self_arg, "base iter"); + multispan_sugg( + diag, + "remove the `.enumerate()` call", + vec![ + (pat.span, snippet(cx, elem.span, "..").into_owned()), + (arg.span, base_iter.to_string()), + ], + ); + }, + ); } - - let Some((DefKind::AssocFn, call_id)) = cx.typeck_results().type_dependent_def(arg.hir_id) else { - return; - }; - - let call_name = cx.tcx.def_path_str(call_id); - - if call_name != "std::iter::Iterator::enumerate" && call_name != "core::iter::Iterator::enumerate" { - return; - } - - span_lint_and_then( - cx, - UNUSED_ENUMERATE_INDEX, - arg.span, - "you seem to use `.enumerate()` and immediately discard the index", - |diag| { - let base_iter = sugg::Sugg::hir(cx, self_arg, "base iter"); - multispan_sugg( - diag, - "remove the `.enumerate()` call", - vec![ - (pat.span, snippet(cx, elem.span, "..").into_owned()), - (arg.span, base_iter.to_string()), - ], - ); - }, - ); } diff --git a/clippy_lints/src/loops/while_immutable_condition.rs b/clippy_lints/src/loops/while_immutable_condition.rs index 3511d24e813..3dff826cb85 100644 --- a/clippy_lints/src/loops/while_immutable_condition.rs +++ b/clippy_lints/src/loops/while_immutable_condition.rs @@ -101,7 +101,7 @@ impl<'a, 'tcx> VarCollectorVisitor<'a, 'tcx> { Res::Local(hir_id) => { self.ids.insert(hir_id); }, - Res::Def(DefKind::Static{..}, def_id) => { + Res::Def(DefKind::Static { .. }, def_id) => { let mutable = self.cx.tcx.is_mutable_static(def_id); self.def_ids.insert(def_id, mutable); }, diff --git a/clippy_lints/src/manual_retain.rs b/clippy_lints/src/manual_retain.rs index 6f15fca089e..3ddb06a1e08 100644 --- a/clippy_lints/src/manual_retain.rs +++ b/clippy_lints/src/manual_retain.rs @@ -2,7 +2,7 @@ use clippy_config::msrvs::{self, Msrv}; use clippy_utils::diagnostics::span_lint_and_sugg; use clippy_utils::source::snippet; use clippy_utils::ty::{is_type_diagnostic_item, is_type_lang_item}; -use clippy_utils::{get_parent_expr, match_def_path, paths, SpanlessEq}; +use clippy_utils::{match_def_path, paths, SpanlessEq}; use rustc_errors::Applicability; use rustc_hir as hir; use rustc_hir::def_id::DefId; @@ -69,17 +69,16 @@ impl_lint_pass!(ManualRetain => [MANUAL_RETAIN]); impl<'tcx> LateLintPass<'tcx> for ManualRetain { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if let Some(parent_expr) = get_parent_expr(cx, expr) - && let Assign(left_expr, collect_expr, _) = &parent_expr.kind + if let Assign(left_expr, collect_expr, _) = &expr.kind && let hir::ExprKind::MethodCall(seg, ..) = &collect_expr.kind && seg.args.is_none() && let hir::ExprKind::MethodCall(_, target_expr, [], _) = &collect_expr.kind && let Some(collect_def_id) = cx.typeck_results().type_dependent_def_id(collect_expr.hir_id) && cx.tcx.is_diagnostic_item(sym::iterator_collect_fn, collect_def_id) { - check_into_iter(cx, left_expr, target_expr, parent_expr.span, &self.msrv); - check_iter(cx, left_expr, target_expr, parent_expr.span, &self.msrv); - check_to_owned(cx, left_expr, target_expr, parent_expr.span, &self.msrv); + check_into_iter(cx, left_expr, target_expr, expr.span, &self.msrv); + check_iter(cx, left_expr, target_expr, expr.span, &self.msrv); + check_to_owned(cx, left_expr, target_expr, expr.span, &self.msrv); } } diff --git a/clippy_lints/src/manual_unwrap_or_default.rs b/clippy_lints/src/manual_unwrap_or_default.rs new file mode 100644 index 00000000000..ddaf97c463a --- /dev/null +++ b/clippy_lints/src/manual_unwrap_or_default.rs @@ -0,0 +1,181 @@ +use rustc_errors::Applicability; +use rustc_hir::def::Res; +use rustc_hir::{Arm, Expr, ExprKind, HirId, LangItem, MatchSource, Pat, PatKind, QPath}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_session::declare_lint_pass; +use rustc_span::sym; + +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::is_default_equivalent; +use clippy_utils::source::snippet_opt; +use clippy_utils::ty::implements_trait; + +declare_clippy_lint! { + /// ### What it does + /// Checks if a `match` or `if let` expression can be simplified using + /// `.unwrap_or_default()`. + /// + /// ### Why is this bad? + /// It can be done in one call with `.unwrap_or_default()`. + /// + /// ### Example + /// ```no_run + /// let x: Option<String> = Some(String::new()); + /// let y: String = match x { + /// Some(v) => v, + /// None => String::new(), + /// }; + /// + /// let x: Option<Vec<String>> = Some(Vec::new()); + /// let y: Vec<String> = if let Some(v) = x { + /// v + /// } else { + /// Vec::new() + /// }; + /// ``` + /// Use instead: + /// ```no_run + /// let x: Option<String> = Some(String::new()); + /// let y: String = x.unwrap_or_default(); + /// + /// let x: Option<Vec<String>> = Some(Vec::new()); + /// let y: Vec<String> = x.unwrap_or_default(); + /// ``` + #[clippy::version = "1.78.0"] + pub MANUAL_UNWRAP_OR_DEFAULT, + suspicious, + "check if a `match` or `if let` can be simplified with `unwrap_or_default`" +} + +declare_lint_pass!(ManualUnwrapOrDefault => [MANUAL_UNWRAP_OR_DEFAULT]); + +fn get_some<'tcx>(cx: &LateContext<'tcx>, pat: &Pat<'tcx>) -> Option<HirId> { + if let PatKind::TupleStruct(QPath::Resolved(_, path), &[pat], _) = pat.kind + && let Some(def_id) = path.res.opt_def_id() + // Since it comes from a pattern binding, we need to get the parent to actually match + // against it. + && let Some(def_id) = cx.tcx.opt_parent(def_id) + && cx.tcx.lang_items().get(LangItem::OptionSome) == Some(def_id) + { + let mut bindings = Vec::new(); + pat.each_binding(|_, id, _, _| bindings.push(id)); + if let &[id] = bindings.as_slice() { + Some(id) + } else { + None + } + } else { + None + } +} + +fn get_none<'tcx>(cx: &LateContext<'tcx>, arm: &Arm<'tcx>) -> Option<&'tcx Expr<'tcx>> { + if let PatKind::Path(QPath::Resolved(_, path)) = arm.pat.kind + && let Some(def_id) = path.res.opt_def_id() + // Since it comes from a pattern binding, we need to get the parent to actually match + // against it. + && let Some(def_id) = cx.tcx.opt_parent(def_id) + && cx.tcx.lang_items().get(LangItem::OptionNone) == Some(def_id) + { + Some(arm.body) + } else if let PatKind::Wild = arm.pat.kind { + // We consider that the `Some` check will filter it out if it's not right. + Some(arm.body) + } else { + None + } +} + +fn get_some_and_none_bodies<'tcx>( + cx: &LateContext<'tcx>, + arm1: &'tcx Arm<'tcx>, + arm2: &'tcx Arm<'tcx>, +) -> Option<((&'tcx Expr<'tcx>, HirId), &'tcx Expr<'tcx>)> { + if let Some(binding_id) = get_some(cx, arm1.pat) + && let Some(body_none) = get_none(cx, arm2) + { + Some(((arm1.body, binding_id), body_none)) + } else if let Some(binding_id) = get_some(cx, arm2.pat) + && let Some(body_none) = get_none(cx, arm1) + { + Some(((arm2.body, binding_id), body_none)) + } else { + None + } +} + +fn handle_match<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool { + let ExprKind::Match(match_expr, [arm1, arm2], MatchSource::Normal | MatchSource::ForLoopDesugar) = expr.kind else { + return false; + }; + // We don't want conditions on the arms to simplify things. + if arm1.guard.is_none() + && arm2.guard.is_none() + // We check that the returned type implements the `Default` trait. + && let match_ty = cx.typeck_results().expr_ty(expr) + && let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default) + && implements_trait(cx, match_ty, default_trait_id, &[]) + // We now get the bodies for both the `Some` and `None` arms. + && let Some(((body_some, binding_id), body_none)) = get_some_and_none_bodies(cx, arm1, arm2) + // We check that the `Some(x) => x` doesn't do anything apart "returning" the value in `Some`. + && let ExprKind::Path(QPath::Resolved(_, path)) = body_some.peel_blocks().kind + && let Res::Local(local_id) = path.res + && local_id == binding_id + // We now check the `None` arm is calling a method equivalent to `Default::default`. + && let body_none = body_none.peel_blocks() + && is_default_equivalent(cx, body_none) + && let Some(match_expr_snippet) = snippet_opt(cx, match_expr.span) + { + span_lint_and_sugg( + cx, + MANUAL_UNWRAP_OR_DEFAULT, + expr.span, + "match can be simplified with `.unwrap_or_default()`", + "replace it with", + format!("{match_expr_snippet}.unwrap_or_default()"), + Applicability::MachineApplicable, + ); + } + true +} + +fn handle_if_let<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { + if let ExprKind::If(cond, if_block, Some(else_expr)) = expr.kind + && let ExprKind::Let(let_) = cond.kind + && let ExprKind::Block(_, _) = else_expr.kind + // We check that the returned type implements the `Default` trait. + && let match_ty = cx.typeck_results().expr_ty(expr) + && let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default) + && implements_trait(cx, match_ty, default_trait_id, &[]) + && let Some(binding_id) = get_some(cx, let_.pat) + // We check that the `Some(x) => x` doesn't do anything apart "returning" the value in `Some`. + && let ExprKind::Path(QPath::Resolved(_, path)) = if_block.peel_blocks().kind + && let Res::Local(local_id) = path.res + && local_id == binding_id + // We now check the `None` arm is calling a method equivalent to `Default::default`. + && let body_else = else_expr.peel_blocks() + && is_default_equivalent(cx, body_else) + && let Some(if_let_expr_snippet) = snippet_opt(cx, let_.init.span) + { + span_lint_and_sugg( + cx, + MANUAL_UNWRAP_OR_DEFAULT, + expr.span, + "if let can be simplified with `.unwrap_or_default()`", + "replace it with", + format!("{if_let_expr_snippet}.unwrap_or_default()"), + Applicability::MachineApplicable, + ); + } +} + +impl<'tcx> LateLintPass<'tcx> for ManualUnwrapOrDefault { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) { + if expr.span.from_expansion() { + return; + } + if !handle_match(cx, expr) { + handle_if_let(cx, expr); + } + } +} diff --git a/clippy_lints/src/matches/single_match.rs b/clippy_lints/src/matches/single_match.rs index 86c414dafcc..a0db8e2db1f 100644 --- a/clippy_lints/src/matches/single_match.rs +++ b/clippy_lints/src/matches/single_match.rs @@ -55,23 +55,15 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>], expr: }; let ty = cx.typeck_results().expr_ty(ex); - if *ty.kind() != ty::Bool || is_lint_allowed(cx, MATCH_BOOL, ex.hir_id) { - check_single_pattern(cx, ex, arms, expr, els); - check_opt_like(cx, ex, arms, expr, ty, els); + if (*ty.kind() != ty::Bool || is_lint_allowed(cx, MATCH_BOOL, ex.hir_id)) && + (check_single_pattern(arms) || check_opt_like(cx, arms, ty)) { + report_single_pattern(cx, ex, arms, expr, els); } } } -fn check_single_pattern( - cx: &LateContext<'_>, - ex: &Expr<'_>, - arms: &[Arm<'_>], - expr: &Expr<'_>, - els: Option<&Expr<'_>>, -) { - if is_wild(arms[1].pat) { - report_single_pattern(cx, ex, arms, expr, els); - } +fn check_single_pattern(arms: &[Arm<'_>]) -> bool { + is_wild(arms[1].pat) } fn report_single_pattern( @@ -140,19 +132,10 @@ fn report_single_pattern( span_lint_and_sugg(cx, lint, expr.span, msg, "try", sugg, app); } -fn check_opt_like<'a>( - cx: &LateContext<'a>, - ex: &Expr<'_>, - arms: &[Arm<'_>], - expr: &Expr<'_>, - ty: Ty<'a>, - els: Option<&Expr<'_>>, -) { +fn check_opt_like<'a>(cx: &LateContext<'a>, arms: &[Arm<'_>], ty: Ty<'a>) -> bool { // We don't want to lint if the second arm contains an enum which could // have more variants in the future. - if form_exhaustive_matches(cx, ty, arms[0].pat, arms[1].pat) { - report_single_pattern(cx, ex, arms, expr, els); - } + form_exhaustive_matches(cx, ty, arms[0].pat, arms[1].pat) } /// Returns `true` if all of the types in the pattern are enums which we know diff --git a/clippy_lints/src/methods/expect_fun_call.rs b/clippy_lints/src/methods/expect_fun_call.rs index e2c2997594a..4d8fb217f7f 100644 --- a/clippy_lints/src/methods/expect_fun_call.rs +++ b/clippy_lints/src/methods/expect_fun_call.rs @@ -91,7 +91,7 @@ pub(super) fn check<'tcx>( }, hir::ExprKind::Path(ref p) => matches!( cx.qpath_res(p, arg.hir_id), - hir::def::Res::Def(hir::def::DefKind::Const | hir::def::DefKind::Static{..}, _) + hir::def::Res::Def(hir::def::DefKind::Const | hir::def::DefKind::Static { .. }, _) ), _ => false, } diff --git a/clippy_lints/src/methods/is_empty.rs b/clippy_lints/src/methods/is_empty.rs new file mode 100644 index 00000000000..7fe66062251 --- /dev/null +++ b/clippy_lints/src/methods/is_empty.rs @@ -0,0 +1,49 @@ +use clippy_utils::consts::constant_is_empty; +use clippy_utils::diagnostics::span_lint; +use clippy_utils::{find_binding_init, path_to_local}; +use rustc_hir::{Expr, HirId}; +use rustc_lint::{LateContext, LintContext}; +use rustc_middle::lint::in_external_macro; +use rustc_span::sym; + +use super::CONST_IS_EMPTY; + +/// Expression whose initialization depend on a constant conditioned by a `#[cfg(…)]` directive will +/// not trigger the lint. +pub(super) fn check(cx: &LateContext<'_>, expr: &'_ Expr<'_>, receiver: &Expr<'_>) { + if in_external_macro(cx.sess(), expr.span) || !receiver.span.eq_ctxt(expr.span) { + return; + } + let init_expr = expr_or_init(cx, receiver); + if !receiver.span.eq_ctxt(init_expr.span) { + return; + } + if let Some(init_is_empty) = constant_is_empty(cx, init_expr) { + span_lint( + cx, + CONST_IS_EMPTY, + expr.span, + &format!("this expression always evaluates to {init_is_empty:?}"), + ); + } +} + +fn is_under_cfg(cx: &LateContext<'_>, id: HirId) -> bool { + cx.tcx + .hir() + .parent_id_iter(id) + .any(|id| cx.tcx.hir().attrs(id).iter().any(|attr| attr.has_name(sym::cfg))) +} + +/// Similar to [`clippy_utils::expr_or_init`], but does not go up the chain if the initialization +/// value depends on a `#[cfg(…)]` directive. +fn expr_or_init<'a, 'b, 'tcx: 'b>(cx: &LateContext<'tcx>, mut expr: &'a Expr<'b>) -> &'a Expr<'b> { + while let Some(init) = path_to_local(expr) + .and_then(|id| find_binding_init(cx, id)) + .filter(|init| cx.typeck_results().expr_adjustments(init).is_empty()) + .filter(|init| !is_under_cfg(cx, init.hir_id)) + { + expr = init; + } + expr +} diff --git a/clippy_lints/src/methods/iter_nth.rs b/clippy_lints/src/methods/iter_nth.rs index 12104310405..5b0b70b4b96 100644 --- a/clippy_lints/src/methods/iter_nth.rs +++ b/clippy_lints/src/methods/iter_nth.rs @@ -1,10 +1,10 @@ -use super::utils::derefs_to_slice; -use crate::methods::iter_nth_zero; -use clippy_utils::diagnostics::span_lint_and_help; -use clippy_utils::ty::is_type_diagnostic_item; +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::ty::get_type_diagnostic_name; +use rustc_errors::Applicability; use rustc_hir as hir; use rustc_lint::LateContext; use rustc_span::symbol::sym; +use rustc_span::Span; use super::ITER_NTH; @@ -12,28 +12,33 @@ pub(super) fn check<'tcx>( cx: &LateContext<'tcx>, expr: &hir::Expr<'_>, iter_recv: &'tcx hir::Expr<'tcx>, - nth_recv: &hir::Expr<'_>, - nth_arg: &hir::Expr<'_>, - is_mut: bool, -) { - let mut_str = if is_mut { "_mut" } else { "" }; - let caller_type = if derefs_to_slice(cx, iter_recv, cx.typeck_results().expr_ty(iter_recv)).is_some() { - "slice" - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(iter_recv), sym::Vec) { - "`Vec`" - } else if is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(iter_recv), sym::VecDeque) { - "`VecDeque`" - } else { - iter_nth_zero::check(cx, expr, nth_recv, nth_arg); - return; // caller is not a type that we want to lint + iter_method: &str, + iter_span: Span, + nth_span: Span, +) -> bool { + let caller_type = match get_type_diagnostic_name(cx, cx.typeck_results().expr_ty(iter_recv).peel_refs()) { + Some(sym::Vec) => "`Vec`", + Some(sym::VecDeque) => "`VecDeque`", + _ if cx.typeck_results().expr_ty_adjusted(iter_recv).peel_refs().is_slice() => "slice", + // caller is not a type that we want to lint + _ => return false, }; - span_lint_and_help( + span_lint_and_then( cx, ITER_NTH, expr.span, - &format!("called `.iter{mut_str}().nth()` on a {caller_type}"), - None, - &format!("calling `.get{mut_str}()` is both faster and more readable"), + &format!("called `.{iter_method}().nth()` on a {caller_type}"), + |diag| { + let get_method = if iter_method == "iter_mut" { "get_mut" } else { "get" }; + diag.span_suggestion_verbose( + iter_span.to(nth_span), + format!("`{get_method}` is equivalent but more concise"), + get_method, + Applicability::MachineApplicable, + ); + }, ); + + true } diff --git a/clippy_lints/src/methods/map_clone.rs b/clippy_lints/src/methods/map_clone.rs index 27e17b43b01..c3c7a3a0033 100644 --- a/clippy_lints/src/methods/map_clone.rs +++ b/clippy_lints/src/methods/map_clone.rs @@ -86,8 +86,11 @@ pub(super) fn check(cx: &LateContext<'_>, e: &hir::Expr<'_>, recv: &hir::Expr<'_ } } }, - hir::ExprKind::Call(call, [_]) => { - if let hir::ExprKind::Path(qpath) = call.kind { + hir::ExprKind::Call(call, args) => { + if let hir::ExprKind::Path(qpath) = call.kind + && let [arg] = args + && ident_eq(name, arg) + { handle_path(cx, call, &qpath, e, recv); } }, @@ -118,7 +121,9 @@ fn handle_path( if let ty::Adt(_, args) = cx.typeck_results().expr_ty(recv).kind() && let args = args.as_slice() && let Some(ty) = args.iter().find_map(|generic_arg| generic_arg.as_type()) - && ty.is_ref() + && let ty::Ref(_, ty, Mutability::Not) = ty.kind() + && let ty::FnDef(_, lst) = cx.typeck_results().expr_ty(arg).kind() + && lst.iter().all(|l| l.as_type() == Some(*ty)) { lint_path(cx, e.span, recv.span, is_copy(cx, ty.peel_refs())); } diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 8a24ccea3a1..b6c474212cd 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -36,6 +36,7 @@ mod inefficient_to_string; mod inspect_for_each; mod into_iter_on_ref; mod is_digit_ascii_radix; +mod is_empty; mod iter_cloned_collect; mod iter_count; mod iter_filter; @@ -118,6 +119,7 @@ mod unnecessary_literal_unwrap; mod unnecessary_result_map_or_else; mod unnecessary_sort_by; mod unnecessary_to_owned; +mod unused_enumerate_index; mod unwrap_expect_used; mod useless_asref; mod utils; @@ -1235,12 +1237,11 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does - /// Checks for usage of `.iter().nth()` (and the related - /// `.iter_mut().nth()`) on standard library types with *O*(1) element access. + /// Checks for usage of `.iter().nth()`/`.iter_mut().nth()` on standard library types that have + /// equivalent `.get()`/`.get_mut()` methods. /// /// ### Why is this bad? - /// `.get()` and `.get_mut()` are more efficient and more - /// readable. + /// `.get()` and `.get_mut()` are equivalent but more concise. /// /// ### Example /// ```no_run @@ -1256,7 +1257,7 @@ declare_clippy_lint! { /// ``` #[clippy::version = "pre 1.29.0"] pub ITER_NTH, - perf, + style, "using `.iter().nth()` on a standard library type with O(1) element access" } @@ -2848,7 +2849,7 @@ declare_clippy_lint! { /// the file is created from scratch, or ensure `truncate` is /// called so that the truncation behaviour is explicit. `truncate(true)` /// will ensure the file is entirely overwritten with new data, whereas - /// `truncate(false)` will explicitely keep the default behavior. + /// `truncate(false)` will explicitly keep the default behavior. /// /// ### Example /// ```rust,no_run @@ -2862,7 +2863,7 @@ declare_clippy_lint! { /// /// OpenOptions::new().create(true).truncate(true); /// ``` - #[clippy::version = "1.75.0"] + #[clippy::version = "1.77.0"] pub SUSPICIOUS_OPEN_OPTIONS, suspicious, "suspicious combination of options for opening a file" @@ -3182,8 +3183,8 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does /// - /// Checks an argument of `seek` method of `Seek` trait - /// and if it start seek from `SeekFrom::Current(0)`, suggests `stream_position` instead. + /// Checks if the `seek` method of the `Seek` trait is called with `SeekFrom::Current(0)`, + /// and if it is, suggests using `stream_position` instead. /// /// ### Why is this bad? /// @@ -3590,7 +3591,7 @@ declare_clippy_lint! { /// ``` #[clippy::version = "1.73.0"] pub READONLY_WRITE_LOCK, - nursery, + perf, "acquiring a write lock when a read lock would work" } @@ -3816,7 +3817,7 @@ declare_clippy_lint! { /// ```no_run /// let _ = std::iter::empty::<Result<i32, ()>>().flatten(); /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub RESULT_FILTER_MAP, complexity, "filtering `Result` for `Ok` then force-unwrapping, which can be one type-safe operation" @@ -3825,7 +3826,7 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does /// Checks for usage of `.filter(Option::is_some)` that may be replaced with a `.flatten()` call. - /// This lint will require additional changes to the follow-up calls as it appects the type. + /// This lint will require additional changes to the follow-up calls as it affects the type. /// /// ### Why is this bad? /// This pattern is often followed by manual unwrapping of the `Option`. The simplification @@ -3842,7 +3843,7 @@ declare_clippy_lint! { /// // example code which does not raise clippy warning /// vec![Some(1)].into_iter().flatten(); /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub ITER_FILTER_IS_SOME, pedantic, "filtering an iterator over `Option`s for `Some` can be achieved with `flatten`" @@ -3851,7 +3852,7 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does /// Checks for usage of `.filter(Result::is_ok)` that may be replaced with a `.flatten()` call. - /// This lint will require additional changes to the follow-up calls as it appects the type. + /// This lint will require additional changes to the follow-up calls as it affects the type. /// /// ### Why is this bad? /// This pattern is often followed by manual unwrapping of `Result`. The simplification @@ -3868,7 +3869,7 @@ declare_clippy_lint! { /// // example code which does not raise clippy warning /// vec![Ok::<i32, String>(1)].into_iter().flatten(); /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub ITER_FILTER_IS_OK, pedantic, "filtering an iterator over `Result`s for `Ok` can be achieved with `flatten`" @@ -3895,7 +3896,7 @@ declare_clippy_lint! { /// option.is_some_and(|a| a > 10); /// result.is_ok_and(|a| a > 10); /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub MANUAL_IS_VARIANT_AND, pedantic, "using `.map(f).unwrap_or_default()`, which is more succinctly expressed as `is_some_and(f)` or `is_ok_and(f)`" @@ -3925,7 +3926,7 @@ declare_clippy_lint! { /// `"\r\n"`), for example during the parsing of a specific file format in which precisely one newline type is /// valid. /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub STR_SPLIT_AT_NEWLINE, pedantic, "splitting a trimmed string at hard-coded newlines" @@ -4044,6 +4045,31 @@ declare_clippy_lint! { "calling `.get().is_some()` or `.get().is_none()` instead of `.contains()` or `.contains_key()`" } +declare_clippy_lint! { + /// ### What it does + /// It identifies calls to `.is_empty()` on constant values. + /// + /// ### Why is this bad? + /// String literals and constant values are known at compile time. Checking if they + /// are empty will always return the same value. This might not be the intention of + /// the expression. + /// + /// ### Example + /// ```no_run + /// let value = ""; + /// if value.is_empty() { + /// println!("the string is empty"); + /// } + /// ``` + /// Use instead: + /// ```no_run + /// println!("the string is empty"); + /// ``` + #[clippy::version = "1.78.0"] + pub CONST_IS_EMPTY, + suspicious, + "is_empty() called on strings known at compile time" +} pub struct Methods { avoid_breaking_exported_api: bool, msrv: Msrv, @@ -4092,6 +4118,7 @@ impl_lint_pass!(Methods => [ CLONE_ON_COPY, CLONE_ON_REF_PTR, COLLAPSIBLE_STR_REPLACE, + CONST_IS_EMPTY, ITER_OVEREAGER_CLONED, CLONED_INSTEAD_OF_COPIED, FLAT_MAP_OPTION, @@ -4403,6 +4430,7 @@ impl Methods { zst_offset::check(cx, expr, recv); }, ("all", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); if let Some(("cloned", recv2, [], _, _)) = method_call(recv) { iter_overeager_cloned::check( cx, @@ -4421,23 +4449,26 @@ impl Methods { unnecessary_lazy_eval::check(cx, expr, recv, arg, "and"); } }, - ("any", [arg]) => match method_call(recv) { - Some(("cloned", recv2, [], _, _)) => iter_overeager_cloned::check( - cx, - expr, - recv, - recv2, - iter_overeager_cloned::Op::NeedlessMove(arg), - false, - ), - Some(("chars", recv, _, _, _)) - if let ExprKind::Closure(arg) = arg.kind - && let body = cx.tcx.hir().body(arg.body) - && let [param] = body.params => - { - string_lit_chars_any::check(cx, expr, recv, param, peel_blocks(body.value), &self.msrv); - }, - _ => {}, + ("any", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); + match method_call(recv) { + Some(("cloned", recv2, [], _, _)) => iter_overeager_cloned::check( + cx, + expr, + recv, + recv2, + iter_overeager_cloned::Op::NeedlessMove(arg), + false, + ), + Some(("chars", recv, _, _, _)) + if let ExprKind::Closure(arg) = arg.kind + && let body = cx.tcx.hir().body(arg.body) + && let [param] = body.params => + { + string_lit_chars_any::check(cx, expr, recv, param, peel_blocks(body.value), &self.msrv); + }, + _ => {}, + } }, ("arg", [arg]) => { suspicious_command_arg_space::check(cx, recv, arg, span); @@ -4445,7 +4476,7 @@ impl Methods { ("as_deref" | "as_deref_mut", []) => { needless_option_as_deref::check(cx, expr, recv, name); }, - ("as_bytes" | "is_empty", []) => { + ("as_bytes", []) => { if let Some(("as_str", recv, [], as_str_span, _)) = method_call(recv) { redundant_as_str::check(cx, expr, recv, as_str_span, span); } @@ -4570,14 +4601,17 @@ impl Methods { } }, ("filter_map", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); unnecessary_filter_map::check(cx, expr, arg, name); filter_map_bool_then::check(cx, expr, arg, call_span); filter_map_identity::check(cx, expr, arg, span); }, ("find_map", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); unnecessary_filter_map::check(cx, expr, arg, name); }, ("flat_map", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); flat_map_identity::check(cx, expr, arg, span); flat_map_option::check(cx, expr, arg, span); }, @@ -4599,17 +4633,20 @@ impl Methods { manual_try_fold::check(cx, expr, init, acc, call_span, &self.msrv); unnecessary_fold::check(cx, expr, init, acc, span); }, - ("for_each", [arg]) => match method_call(recv) { - Some(("inspect", _, [_], span2, _)) => inspect_for_each::check(cx, expr, span2), - Some(("cloned", recv2, [], _, _)) => iter_overeager_cloned::check( - cx, - expr, - recv, - recv2, - iter_overeager_cloned::Op::NeedlessMove(arg), - false, - ), - _ => {}, + ("for_each", [arg]) => { + unused_enumerate_index::check(cx, expr, recv, arg); + match method_call(recv) { + Some(("inspect", _, [_], span2, _)) => inspect_for_each::check(cx, expr, span2), + Some(("cloned", recv2, [], _, _)) => iter_overeager_cloned::check( + cx, + expr, + recv, + recv2, + iter_overeager_cloned::Op::NeedlessMove(arg), + false, + ), + _ => {}, + } }, ("get", [arg]) => { get_first::check(cx, expr, recv, arg); @@ -4619,6 +4656,12 @@ impl Methods { ("hash", [arg]) => { unit_hash::check(cx, expr, recv, arg); }, + ("is_empty", []) => { + if let Some(("as_str", recv, [], as_str_span, _)) = method_call(recv) { + redundant_as_str::check(cx, expr, recv, as_str_span, span); + } + is_empty::check(cx, expr, recv); + }, ("is_file", []) => filetype_is_file::check(cx, expr, recv), ("is_digit", [radix]) => is_digit_ascii_radix::check(cx, expr, recv, radix, &self.msrv), ("is_none", []) => check_is_some_is_none(cx, expr, recv, call_span, false), @@ -4650,6 +4693,7 @@ impl Methods { }, (name @ ("map" | "map_err"), [m_arg]) => { if name == "map" { + unused_enumerate_index::check(cx, expr, recv, m_arg); map_clone::check(cx, expr, recv, m_arg, &self.msrv); match method_call(recv) { Some((map_name @ ("iter" | "into_iter"), recv2, _, _, _)) => { @@ -4723,8 +4767,11 @@ impl Methods { iter_overeager_cloned::Op::LaterCloned, false, ), - Some(("iter", recv2, [], _, _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, false), - Some(("iter_mut", recv2, [], _, _)) => iter_nth::check(cx, expr, recv2, recv, n_arg, true), + Some((iter_method @ ("iter" | "iter_mut"), iter_recv, [], iter_span, _)) => { + if !iter_nth::check(cx, expr, iter_recv, iter_method, iter_span, span) { + iter_nth_zero::check(cx, expr, recv, n_arg); + } + }, _ => iter_nth_zero::check(cx, expr, recv, n_arg), }, ("ok_or_else", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "ok_or"), diff --git a/clippy_lints/src/methods/no_effect_replace.rs b/clippy_lints/src/methods/no_effect_replace.rs index 81df32bdee2..a301a5f7d65 100644 --- a/clippy_lints/src/methods/no_effect_replace.rs +++ b/clippy_lints/src/methods/no_effect_replace.rs @@ -25,6 +25,7 @@ pub(super) fn check<'tcx>( && param1 == param2.as_str() { span_lint(cx, NO_EFFECT_REPLACE, expr.span, "replacing text with itself"); + return; } if SpanlessEq::new(cx).eq_expr(arg1, arg2) { diff --git a/clippy_lints/src/methods/unnecessary_sort_by.rs b/clippy_lints/src/methods/unnecessary_sort_by.rs index 6911da69b94..a92fe9e55a4 100644 --- a/clippy_lints/src/methods/unnecessary_sort_by.rs +++ b/clippy_lints/src/methods/unnecessary_sort_by.rs @@ -5,7 +5,8 @@ use clippy_utils::ty::implements_trait; use rustc_errors::Applicability; use rustc_hir::{Closure, Expr, ExprKind, Mutability, Param, Pat, PatKind, Path, PathSegment, QPath}; use rustc_lint::LateContext; -use rustc_middle::ty::{self, GenericArgKind}; +use rustc_middle::ty; +use rustc_middle::ty::GenericArgKind; use rustc_span::sym; use rustc_span::symbol::Ident; use std::iter; diff --git a/clippy_lints/src/methods/unused_enumerate_index.rs b/clippy_lints/src/methods/unused_enumerate_index.rs new file mode 100644 index 00000000000..e5cc898612e --- /dev/null +++ b/clippy_lints/src/methods/unused_enumerate_index.rs @@ -0,0 +1,135 @@ +use clippy_utils::diagnostics::{multispan_sugg_with_applicability, span_lint_hir_and_then}; +use clippy_utils::paths::{CORE_ITER_ENUMERATE_METHOD, CORE_ITER_ENUMERATE_STRUCT}; +use clippy_utils::source::{snippet, snippet_opt}; +use clippy_utils::{expr_or_init, is_trait_method, match_def_path, pat_is_wild}; +use rustc_errors::Applicability; +use rustc_hir::{Expr, ExprKind, FnDecl, PatKind, TyKind}; +use rustc_lint::LateContext; +use rustc_middle::ty::AdtDef; +use rustc_span::{sym, Span}; + +use crate::loops::UNUSED_ENUMERATE_INDEX; + +/// Check for the `UNUSED_ENUMERATE_INDEX` lint outside of loops. +/// +/// The lint is declared in `clippy_lints/src/loops/mod.rs`. There, the following pattern is +/// checked: +/// ```ignore +/// for (_, x) in some_iter.enumerate() { +/// // Index is ignored +/// } +/// ``` +/// +/// This `check` function checks for chained method calls constructs where we can detect that the +/// index is unused. Currently, this checks only for the following patterns: +/// ```ignore +/// some_iter.enumerate().map_function(|(_, x)| ..) +/// let x = some_iter.enumerate(); +/// x.map_function(|(_, x)| ..) +/// ``` +/// where `map_function` is one of `all`, `any`, `filter_map`, `find_map`, `flat_map`, `for_each` or +/// `map`. +/// +/// # Preconditions +/// This function must be called not on the `enumerate` call expression itself, but on any of the +/// map functions listed above. It will ensure that `recv` is a `std::iter::Enumerate` instance and +/// that the method call is one of the `std::iter::Iterator` trait. +/// +/// * `call_expr`: The map function call expression +/// * `recv`: The receiver of the call +/// * `closure_arg`: The argument to the map function call containing the closure/function to apply +pub(super) fn check(cx: &LateContext<'_>, call_expr: &Expr<'_>, recv: &Expr<'_>, closure_arg: &Expr<'_>) { + let recv_ty = cx.typeck_results().expr_ty(recv); + if let Some(recv_ty_defid) = recv_ty.ty_adt_def().map(AdtDef::did) + // If we call a method on a `std::iter::Enumerate` instance + && match_def_path(cx, recv_ty_defid, &CORE_ITER_ENUMERATE_STRUCT) + // If we are calling a method of the `Iterator` trait + && is_trait_method(cx, call_expr, sym::Iterator) + // And the map argument is a closure + && let ExprKind::Closure(closure) = closure_arg.kind + && let closure_body = cx.tcx.hir().body(closure.body) + // And that closure has one argument ... + && let [closure_param] = closure_body.params + // .. which is a tuple of 2 elements + && let PatKind::Tuple([index, elem], ..) = closure_param.pat.kind + // And that the first element (the index) is either `_` or unused in the body + && pat_is_wild(cx, &index.kind, closure_body) + // Try to find the initializer for `recv`. This is needed in case `recv` is a local_binding. In the + // first example below, `expr_or_init` would return `recv`. + // ``` + // iter.enumerate().map(|(_, x)| x) + // ^^^^^^^^^^^^^^^^ `recv`, a call to `std::iter::Iterator::enumerate` + // + // let binding = iter.enumerate(); + // ^^^^^^^^^^^^^^^^ `recv_init_expr` + // binding.map(|(_, x)| x) + // ^^^^^^^ `recv`, not a call to `std::iter::Iterator::enumerate` + // ``` + && let recv_init_expr = expr_or_init(cx, recv) + // Make sure the initializer is a method call. It may be that the `Enumerate` comes from something + // that we cannot control. + // This would for instance happen with: + // ``` + // external_lib::some_function_returning_enumerate().map(|(_, x)| x) + // ``` + && let ExprKind::MethodCall(_, enumerate_recv, _, enumerate_span) = recv_init_expr.kind + && let Some(enumerate_defid) = cx.typeck_results().type_dependent_def_id(recv_init_expr.hir_id) + // Make sure the method call is `std::iter::Iterator::enumerate`. + && match_def_path(cx, enumerate_defid, &CORE_ITER_ENUMERATE_METHOD) + { + // Check if the tuple type was explicit. It may be the type system _needs_ the type of the element + // that would be explicited in the closure. + let new_closure_param = match find_elem_explicit_type_span(closure.fn_decl) { + // We have an explicit type. Get its snippet, that of the binding name, and do `binding: ty`. + // Fallback to `..` if we fail getting either snippet. + Some(ty_span) => snippet_opt(cx, elem.span) + .and_then(|binding_name| snippet_opt(cx, ty_span).map(|ty_name| format!("{binding_name}: {ty_name}"))) + .unwrap_or_else(|| "..".to_string()), + // Otherwise, we have no explicit type. We can replace with the binding name of the element. + None => snippet(cx, elem.span, "..").into_owned(), + }; + + // Suggest removing the tuple from the closure and the preceding call to `enumerate`, whose span we + // can get from the `MethodCall`. + span_lint_hir_and_then( + cx, + UNUSED_ENUMERATE_INDEX, + recv_init_expr.hir_id, + enumerate_span, + "you seem to use `.enumerate()` and immediately discard the index", + |diag| { + multispan_sugg_with_applicability( + diag, + "remove the `.enumerate()` call", + Applicability::MachineApplicable, + vec![ + (closure_param.span, new_closure_param), + ( + enumerate_span.with_lo(enumerate_recv.span.source_callsite().hi()), + String::new(), + ), + ], + ); + }, + ); + } +} + +/// Find the span of the explicit type of the element. +/// +/// # Returns +/// If the tuple argument: +/// * Has no explicit type, returns `None` +/// * Has an explicit tuple type with an implicit element type (`(usize, _)`), returns `None` +/// * Has an explicit tuple type with an explicit element type (`(_, i32)`), returns the span for +/// the element type. +fn find_elem_explicit_type_span(fn_decl: &FnDecl<'_>) -> Option<Span> { + if let [tuple_ty] = fn_decl.inputs + && let TyKind::Tup([_idx_ty, elem_ty]) = tuple_ty.kind + && !matches!(elem_ty.kind, TyKind::Err(..) | TyKind::Infer) + { + Some(elem_ty.span) + } else { + None + } +} diff --git a/clippy_lints/src/missing_doc.rs b/clippy_lints/src/missing_doc.rs index bf4af7946f4..6878fb3349d 100644 --- a/clippy_lints/src/missing_doc.rs +++ b/clippy_lints/src/missing_doc.rs @@ -8,6 +8,7 @@ use clippy_utils::attrs::is_doc_hidden; use clippy_utils::diagnostics::span_lint; use clippy_utils::is_from_proc_macro; +use clippy_utils::source::snippet_opt; use rustc_ast::ast::{self, MetaItem, MetaItemKind}; use rustc_hir as hir; use rustc_hir::def_id::LocalDefId; @@ -32,6 +33,13 @@ declare_clippy_lint! { "detects missing documentation for private members" } +macro_rules! note_prev_span_then_ret { + ($prev_span:expr, $span:expr) => {{ + $prev_span = Some($span); + return; + }}; +} + pub struct MissingDoc { /// Whether to **only** check for missing documentation in items visible within the current /// crate. For example, `pub(crate)` items. @@ -39,6 +47,8 @@ pub struct MissingDoc { /// Stack of whether #[doc(hidden)] is set /// at each level which has lint attributes. doc_hidden_stack: Vec<bool>, + /// Used to keep tracking of the previous item, field or variants etc, to get the search span. + prev_span: Option<Span>, } impl Default for MissingDoc { @@ -54,6 +64,7 @@ impl MissingDoc { Self { crate_items_only, doc_hidden_stack: vec![false], + prev_span: None, } } @@ -108,7 +119,8 @@ impl MissingDoc { let has_doc = attrs .iter() - .any(|a| a.doc_str().is_some() || Self::has_include(a.meta())); + .any(|a| a.doc_str().is_some() || Self::has_include(a.meta())) + || matches!(self.search_span(sp), Some(span) if span_to_snippet_contains_docs(cx, span)); if !has_doc { span_lint( @@ -119,6 +131,32 @@ impl MissingDoc { ); } } + + /// Return a span to search for doc comments manually. + /// + /// # Example + /// ```ignore + /// fn foo() { ... } + /// ^^^^^^^^^^^^^^^^ prev_span + /// ↑ + /// | search_span | + /// ↓ + /// fn bar() { ... } + /// ^^^^^^^^^^^^^^^^ cur_span + /// ``` + fn search_span(&self, cur_span: Span) -> Option<Span> { + let prev_span = self.prev_span?; + let start_pos = if prev_span.contains(cur_span) { + // In case when the prev_span is an entire struct, or enum, + // and the current span is a field, or variant, we need to search from + // the starting pos of the previous span. + prev_span.lo() + } else { + prev_span.hi() + }; + let search_span = cur_span.with_lo(start_pos).with_hi(cur_span.lo()); + Some(search_span) + } } impl_lint_pass!(MissingDoc => [MISSING_DOCS_IN_PRIVATE_ITEMS]); @@ -138,6 +176,10 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { self.check_missing_docs_attrs(cx, CRATE_DEF_ID, attrs, cx.tcx.def_span(CRATE_DEF_ID), "the", "crate"); } + fn check_crate_post(&mut self, _: &LateContext<'tcx>) { + self.prev_span = None; + } + fn check_item(&mut self, cx: &LateContext<'tcx>, it: &'tcx hir::Item<'_>) { match it.kind { hir::ItemKind::Fn(..) => { @@ -145,7 +187,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { if it.ident.name == sym::main { let at_root = cx.tcx.local_parent(it.owner_id.def_id) == CRATE_DEF_ID; if at_root { - return; + note_prev_span_then_ret!(self.prev_span, it.span); } } }, @@ -164,7 +206,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { | hir::ItemKind::ForeignMod { .. } | hir::ItemKind::GlobalAsm(..) | hir::ItemKind::Impl { .. } - | hir::ItemKind::Use(..) => return, + | hir::ItemKind::Use(..) => note_prev_span_then_ret!(self.prev_span, it.span), }; let (article, desc) = cx.tcx.article_and_description(it.owner_id.to_def_id()); @@ -173,6 +215,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { if !is_from_proc_macro(cx, it) { self.check_missing_docs_attrs(cx, it.owner_id.def_id, attrs, it.span, article, desc); } + self.prev_span = Some(it.span); } fn check_trait_item(&mut self, cx: &LateContext<'tcx>, trait_item: &'tcx hir::TraitItem<'_>) { @@ -182,16 +225,17 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { if !is_from_proc_macro(cx, trait_item) { self.check_missing_docs_attrs(cx, trait_item.owner_id.def_id, attrs, trait_item.span, article, desc); } + self.prev_span = Some(trait_item.span); } fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) { // If the method is an impl for a trait, don't doc. if let Some(cid) = cx.tcx.associated_item(impl_item.owner_id).impl_container(cx.tcx) { if cx.tcx.impl_trait_ref(cid).is_some() { - return; + note_prev_span_then_ret!(self.prev_span, impl_item.span); } } else { - return; + note_prev_span_then_ret!(self.prev_span, impl_item.span); } let (article, desc) = cx.tcx.article_and_description(impl_item.owner_id.to_def_id()); @@ -199,6 +243,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { if !is_from_proc_macro(cx, impl_item) { self.check_missing_docs_attrs(cx, impl_item.owner_id.def_id, attrs, impl_item.span, article, desc); } + self.prev_span = Some(impl_item.span); } fn check_field_def(&mut self, cx: &LateContext<'tcx>, sf: &'tcx hir::FieldDef<'_>) { @@ -208,6 +253,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { self.check_missing_docs_attrs(cx, sf.def_id, attrs, sf.span, "a", "struct field"); } } + self.prev_span = Some(sf.span); } fn check_variant(&mut self, cx: &LateContext<'tcx>, v: &'tcx hir::Variant<'_>) { @@ -215,5 +261,13 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc { if !is_from_proc_macro(cx, v) { self.check_missing_docs_attrs(cx, v.def_id, attrs, v.span, "a", "variant"); } + self.prev_span = Some(v.span); } } + +fn span_to_snippet_contains_docs(cx: &LateContext<'_>, search_span: Span) -> bool { + let Some(snippet) = snippet_opt(cx, search_span) else { + return false; + }; + snippet.lines().rev().any(|line| line.trim().starts_with("///")) +} diff --git a/clippy_lints/src/multiple_unsafe_ops_per_block.rs b/clippy_lints/src/multiple_unsafe_ops_per_block.rs index 70fd07cd93c..648d780ac09 100644 --- a/clippy_lints/src/multiple_unsafe_ops_per_block.rs +++ b/clippy_lints/src/multiple_unsafe_ops_per_block.rs @@ -109,7 +109,14 @@ fn collect_unsafe_exprs<'tcx>( ExprKind::Path(QPath::Resolved( _, hir::Path { - res: Res::Def(DefKind::Static{mutability:Mutability::Mut, ..}, _), + res: + Res::Def( + DefKind::Static { + mutability: Mutability::Mut, + .. + }, + _, + ), .. }, )) => { @@ -149,7 +156,13 @@ fn collect_unsafe_exprs<'tcx>( ExprKind::Path(QPath::Resolved( _, hir::Path { - res: Res::Def(DefKind::Static{mutability:Mutability::Mut, ..}, _), + res: Res::Def( + DefKind::Static { + mutability: Mutability::Mut, + .. + }, + _ + ), .. } )) diff --git a/clippy_lints/src/mut_mut.rs b/clippy_lints/src/mut_mut.rs index 72a2cca1e40..bc7b2c6b7c1 100644 --- a/clippy_lints/src/mut_mut.rs +++ b/clippy_lints/src/mut_mut.rs @@ -1,4 +1,4 @@ -use clippy_utils::diagnostics::span_lint; +use clippy_utils::diagnostics::{span_lint, span_lint_hir}; use clippy_utils::higher; use rustc_hir as hir; use rustc_hir::intravisit; @@ -35,9 +35,34 @@ impl<'tcx> LateLintPass<'tcx> for MutMut { } fn check_ty(&mut self, cx: &LateContext<'tcx>, ty: &'tcx hir::Ty<'_>) { - use rustc_hir::intravisit::Visitor; + if in_external_macro(cx.sess(), ty.span) { + return; + } - MutVisitor { cx }.visit_ty(ty); + if let hir::TyKind::Ref( + _, + hir::MutTy { + ty: pty, + mutbl: hir::Mutability::Mut, + }, + ) = ty.kind + { + if let hir::TyKind::Ref( + _, + hir::MutTy { + mutbl: hir::Mutability::Mut, + .. + }, + ) = pty.kind + { + span_lint( + cx, + MUT_MUT, + ty.span, + "generally you want to avoid `&mut &mut _` if possible", + ); + } + } } } @@ -62,17 +87,19 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for MutVisitor<'a, 'tcx> { intravisit::walk_expr(self, body); } else if let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, e) = expr.kind { if let hir::ExprKind::AddrOf(hir::BorrowKind::Ref, hir::Mutability::Mut, _) = e.kind { - span_lint( + span_lint_hir( self.cx, MUT_MUT, + expr.hir_id, expr.span, "generally you want to avoid `&mut &mut _` if possible", ); } else if let ty::Ref(_, ty, hir::Mutability::Mut) = self.cx.typeck_results().expr_ty(e).kind() { if ty.peel_refs().is_sized(self.cx.tcx, self.cx.param_env) { - span_lint( + span_lint_hir( self.cx, MUT_MUT, + expr.hir_id, expr.span, "this expression mutably borrows a mutable reference. Consider reborrowing", ); @@ -80,37 +107,4 @@ impl<'a, 'tcx> intravisit::Visitor<'tcx> for MutVisitor<'a, 'tcx> { } } } - - fn visit_ty(&mut self, ty: &'tcx hir::Ty<'_>) { - if in_external_macro(self.cx.sess(), ty.span) { - return; - } - - if let hir::TyKind::Ref( - _, - hir::MutTy { - ty: pty, - mutbl: hir::Mutability::Mut, - }, - ) = ty.kind - { - if let hir::TyKind::Ref( - _, - hir::MutTy { - mutbl: hir::Mutability::Mut, - .. - }, - ) = pty.kind - { - span_lint( - self.cx, - MUT_MUT, - ty.span, - "generally you want to avoid `&mut &mut _` if possible", - ); - } - } - - intravisit::walk_ty(self, ty); - } } diff --git a/clippy_lints/src/mutable_debug_assertion.rs b/clippy_lints/src/mutable_debug_assertion.rs index 96cd81ecdf3..2d7ce7b52ae 100644 --- a/clippy_lints/src/mutable_debug_assertion.rs +++ b/clippy_lints/src/mutable_debug_assertion.rs @@ -96,10 +96,6 @@ impl<'a, 'tcx> Visitor<'tcx> for MutArgVisitor<'a, 'tcx> { self.found = true; return; }, - ExprKind::If(..) => { - self.found = true; - return; - }, ExprKind::Path(_) => { if let Some(adj) = self.cx.typeck_results().adjustments().get(expr.hir_id) { if adj diff --git a/clippy_lints/src/non_copy_const.rs b/clippy_lints/src/non_copy_const.rs index cebd2385656..6cb84bb78b6 100644 --- a/clippy_lints/src/non_copy_const.rs +++ b/clippy_lints/src/non_copy_const.rs @@ -290,14 +290,21 @@ impl NonCopyConst { promoted: None, }; let param_env = cx.tcx.param_env(def_id).with_reveal_all_normalized(cx.tcx); - let result = cx.tcx.const_eval_global_id_for_typeck(param_env, cid, rustc_span::DUMMY_SP); + let result = cx + .tcx + .const_eval_global_id_for_typeck(param_env, cid, rustc_span::DUMMY_SP); self.is_value_unfrozen_raw(cx, result, ty) } fn is_value_unfrozen_expr<'tcx>(&self, cx: &LateContext<'tcx>, hir_id: HirId, def_id: DefId, ty: Ty<'tcx>) -> bool { let args = cx.typeck_results().node_args(hir_id); - let result = Self::const_eval_resolve(cx.tcx, cx.param_env, ty::UnevaluatedConst::new(def_id, args), rustc_span::DUMMY_SP); + let result = Self::const_eval_resolve( + cx.tcx, + cx.param_env, + ty::UnevaluatedConst::new(def_id, args), + rustc_span::DUMMY_SP, + ); self.is_value_unfrozen_raw(cx, result, ty) } diff --git a/clippy_lints/src/read_zero_byte_vec.rs b/clippy_lints/src/read_zero_byte_vec.rs index d0b37cd92e0..0ebdb031d5a 100644 --- a/clippy_lints/src/read_zero_byte_vec.rs +++ b/clippy_lints/src/read_zero_byte_vec.rs @@ -1,4 +1,4 @@ -use clippy_utils::diagnostics::{span_lint, span_lint_and_sugg}; +use clippy_utils::diagnostics::{span_lint_hir, span_lint_hir_and_then}; use clippy_utils::get_enclosing_block; use clippy_utils::higher::{get_vec_init_kind, VecInitKind}; use clippy_utils::source::snippet; @@ -77,37 +77,53 @@ impl<'tcx> LateLintPass<'tcx> for ReadZeroByteVec { if let Some(expr) = visitor.read_zero_expr { let applicability = Applicability::MaybeIncorrect; match vec_init_kind { - VecInitKind::WithConstCapacity(len) => { - span_lint_and_sugg( + VecInitKind::WithConstCapacity(len) => span_lint_hir_and_then( + cx, + READ_ZERO_BYTE_VEC, + expr.hir_id, + expr.span, + "reading zero byte data to `Vec`", + |diag| { + diag.span_suggestion( + expr.span, + "try", + format!("{}.resize({len}, 0); {}", ident.as_str(), snippet(cx, expr.span, "..")), + applicability, + ); + }, + ), + VecInitKind::WithExprCapacity(hir_id) => { + let e = cx.tcx.hir().expect_expr(hir_id); + span_lint_hir_and_then( cx, READ_ZERO_BYTE_VEC, + expr.hir_id, expr.span, "reading zero byte data to `Vec`", - "try", - format!("{}.resize({len}, 0); {}", ident.as_str(), snippet(cx, expr.span, "..")), - applicability, + |diag| { + diag.span_suggestion( + expr.span, + "try", + format!( + "{}.resize({}, 0); {}", + ident.as_str(), + snippet(cx, e.span, ".."), + snippet(cx, expr.span, "..") + ), + applicability, + ); + }, ); }, - VecInitKind::WithExprCapacity(hir_id) => { - let e = cx.tcx.hir().expect_expr(hir_id); - span_lint_and_sugg( + _ => { + span_lint_hir( cx, READ_ZERO_BYTE_VEC, + expr.hir_id, expr.span, "reading zero byte data to `Vec`", - "try", - format!( - "{}.resize({}, 0); {}", - ident.as_str(), - snippet(cx, e.span, ".."), - snippet(cx, expr.span, "..") - ), - applicability, ); }, - _ => { - span_lint(cx, READ_ZERO_BYTE_VEC, expr.span, "reading zero byte data to `Vec`"); - }, } } } diff --git a/clippy_lints/src/redundant_closure_call.rs b/clippy_lints/src/redundant_closure_call.rs index c2673bc409f..435899ddaa7 100644 --- a/clippy_lints/src/redundant_closure_call.rs +++ b/clippy_lints/src/redundant_closure_call.rs @@ -1,5 +1,5 @@ use crate::rustc_lint::LintContext; -use clippy_utils::diagnostics::{span_lint, span_lint_and_then}; +use clippy_utils::diagnostics::{span_lint_and_then, span_lint_hir}; use clippy_utils::get_parent_expr; use clippy_utils::sugg::Sugg; use hir::Param; @@ -273,9 +273,10 @@ impl<'tcx> LateLintPass<'tcx> for RedundantClosureCall { && ident == path.segments[0].ident && count_closure_usage(cx, block, path) == 1 { - span_lint( + span_lint_hir( cx, REDUNDANT_CLOSURE_CALL, + second.hir_id, second.span, "closure called just once immediately after it was declared", ); diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs index 19697527467..8bc24eda465 100644 --- a/clippy_lints/src/returns.rs +++ b/clippy_lints/src/returns.rs @@ -1,4 +1,4 @@ -use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then, span_lint_hir_and_then}; +use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then}; use clippy_utils::source::{snippet_opt, snippet_with_context}; use clippy_utils::sugg::has_enclosing_paren; use clippy_utils::visitors::{for_each_expr_with_closures, Descend}; @@ -380,7 +380,7 @@ fn check_final_expr<'tcx>( return; } - emit_return_lint(cx, ret_span, semi_spans, &replacement); + emit_return_lint(cx, ret_span, semi_spans, &replacement, expr.hir_id); }, ExprKind::If(_, then, else_clause_opt) => { check_block_return(cx, &then.kind, peeled_drop_expr.span, semi_spans.clone()); @@ -415,18 +415,31 @@ fn expr_contains_conjunctive_ifs<'tcx>(expr: &'tcx Expr<'tcx>) -> bool { contains_if(expr, false) } -fn emit_return_lint(cx: &LateContext<'_>, ret_span: Span, semi_spans: Vec<Span>, replacement: &RetReplacement<'_>) { +fn emit_return_lint( + cx: &LateContext<'_>, + ret_span: Span, + semi_spans: Vec<Span>, + replacement: &RetReplacement<'_>, + at: HirId, +) { if ret_span.from_expansion() { return; } - span_lint_and_then(cx, NEEDLESS_RETURN, ret_span, "unneeded `return` statement", |diag| { - let suggestions = std::iter::once((ret_span, replacement.to_string())) - .chain(semi_spans.into_iter().map(|span| (span, String::new()))) - .collect(); + span_lint_hir_and_then( + cx, + NEEDLESS_RETURN, + at, + ret_span, + "unneeded `return` statement", + |diag| { + let suggestions = std::iter::once((ret_span, replacement.to_string())) + .chain(semi_spans.into_iter().map(|span| (span, String::new()))) + .collect(); - diag.multipart_suggestion_verbose(replacement.sugg_help(), suggestions, replacement.applicability()); - }); + diag.multipart_suggestion_verbose(replacement.sugg_help(), suggestions, replacement.applicability()); + }, + ); } fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) -> bool { @@ -452,8 +465,8 @@ fn last_statement_borrows<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) // Go backwards while encountering whitespace and extend the given Span to that point. fn extend_span_to_previous_non_ws(cx: &LateContext<'_>, sp: Span) -> Span { if let Ok(prev_source) = cx.sess().source_map().span_to_prev_source(sp) { - let ws = [' ', '\t', '\n']; - if let Some(non_ws_pos) = prev_source.rfind(|c| !ws.contains(&c)) { + let ws = [b' ', b'\t', b'\n']; + if let Some(non_ws_pos) = prev_source.bytes().rposition(|c| !ws.contains(&c)) { let len = prev_source.len() - non_ws_pos - 1; return sp.with_lo(sp.lo() - BytePos::from_usize(len)); } diff --git a/clippy_lints/src/std_instead_of_core.rs b/clippy_lints/src/std_instead_of_core.rs index c0e4f3c368a..cf839941123 100644 --- a/clippy_lints/src/std_instead_of_core.rs +++ b/clippy_lints/src/std_instead_of_core.rs @@ -109,6 +109,7 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports { sym::core => (STD_INSTEAD_OF_CORE, "std", "core"), sym::alloc => (STD_INSTEAD_OF_ALLOC, "std", "alloc"), _ => { + self.prev_span = first_segment.ident.span; return; }, }, @@ -116,6 +117,7 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports { if cx.tcx.crate_name(def_id.krate) == sym::core { (ALLOC_INSTEAD_OF_CORE, "alloc", "core") } else { + self.prev_span = first_segment.ident.span; return; } }, diff --git a/clippy_lints/src/thread_local_initializer_can_be_made_const.rs b/clippy_lints/src/thread_local_initializer_can_be_made_const.rs index 1af3733ebfa..f8bdb866ca3 100644 --- a/clippy_lints/src/thread_local_initializer_can_be_made_const.rs +++ b/clippy_lints/src/thread_local_initializer_can_be_made_const.rs @@ -37,7 +37,7 @@ declare_clippy_lint! { /// static BUF: String = const { String::new() }; /// } /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub THREAD_LOCAL_INITIALIZER_CAN_BE_MADE_CONST, perf, "suggest using `const` in `thread_local!` macro" diff --git a/clippy_lints/src/transmute/mod.rs b/clippy_lints/src/transmute/mod.rs index e47b14bf63b..3c11b481310 100644 --- a/clippy_lints/src/transmute/mod.rs +++ b/clippy_lints/src/transmute/mod.rs @@ -514,7 +514,7 @@ declare_clippy_lint! { /// ^^^^ ^^ `bool::then` only executes the closure if the condition is true! /// } /// ``` - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub EAGER_TRANSMUTE, correctness, "eager evaluation of `transmute`" diff --git a/clippy_lints/src/types/mod.rs b/clippy_lints/src/types/mod.rs index bdef82e9c5e..2ad15ac8312 100644 --- a/clippy_lints/src/types/mod.rs +++ b/clippy_lints/src/types/mod.rs @@ -392,6 +392,10 @@ impl<'tcx> LateLintPass<'tcx> for Types { } fn check_field_def(&mut self, cx: &LateContext<'tcx>, field: &hir::FieldDef<'tcx>) { + if field.span.from_expansion() { + return; + } + let is_exported = cx.effective_visibilities.is_exported(field.def_id); self.check_ty( diff --git a/clippy_lints/src/unconditional_recursion.rs b/clippy_lints/src/unconditional_recursion.rs index 224ec475c51..d638af2b78b 100644 --- a/clippy_lints/src/unconditional_recursion.rs +++ b/clippy_lints/src/unconditional_recursion.rs @@ -1,5 +1,5 @@ use clippy_utils::diagnostics::span_lint_and_then; -use clippy_utils::{expr_or_init, get_trait_def_id, path_def_id}; +use clippy_utils::{expr_or_init, fn_def_id_with_node_args, path_def_id}; use rustc_ast::BinOpKind; use rustc_data_structures::fx::FxHashMap; use rustc_hir as hir; @@ -19,11 +19,11 @@ use rustc_trait_selection::traits::error_reporting::suggestions::ReturnsVisitor; declare_clippy_lint! { /// ### What it does - /// Checks that there isn't an infinite recursion in `PartialEq` trait - /// implementation. + /// Checks that there isn't an infinite recursion in trait + /// implementations. /// /// ### Why is this bad? - /// This is a hard to find infinite recursion which will crashing any code + /// This is a hard to find infinite recursion that will crash any code. /// using it. /// /// ### Example @@ -42,7 +42,7 @@ declare_clippy_lint! { /// Use instead: /// /// In such cases, either use `#[derive(PartialEq)]` or don't implement it. - #[clippy::version = "1.76.0"] + #[clippy::version = "1.77.0"] pub UNCONDITIONAL_RECURSION, suspicious, "detect unconditional recursion in some traits implementation" @@ -201,7 +201,6 @@ fn check_partial_eq(cx: &LateContext<'_>, method_span: Span, method_def_id: Loca } } -#[allow(clippy::unnecessary_def_path)] fn check_to_string(cx: &LateContext<'_>, method_span: Span, method_def_id: LocalDefId, name: Ident, expr: &Expr<'_>) { let args = cx .tcx @@ -224,7 +223,7 @@ fn check_to_string(cx: &LateContext<'_>, method_span: Span, method_def_id: Local && let Some(trait_) = impl_.of_trait && let Some(trait_def_id) = trait_.trait_def_id() // The trait is `ToString`. - && Some(trait_def_id) == get_trait_def_id(cx, &["alloc", "string", "ToString"]) + && cx.tcx.is_diagnostic_item(sym::ToString, trait_def_id) { let is_bad = match expr.kind { ExprKind::MethodCall(segment, _receiver, &[_arg], _) if segment.ident.name == name.name => { @@ -291,7 +290,6 @@ where self.map } - #[allow(clippy::unnecessary_def_path)] fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) { if self.found_default_call { return; @@ -303,7 +301,7 @@ where && is_default_method_on_current_ty(self.cx.tcx, qpath, self.implemented_ty_id) && let Some(method_def_id) = path_def_id(self.cx, f) && let Some(trait_def_id) = self.cx.tcx.trait_of_item(method_def_id) - && Some(trait_def_id) == get_trait_def_id(self.cx, &["core", "default", "Default"]) + && self.cx.tcx.is_diagnostic_item(sym::Default, trait_def_id) { self.found_default_call = true; span_error(self.cx, self.method_span, expr); @@ -312,10 +310,9 @@ where } impl UnconditionalRecursion { - #[allow(clippy::unnecessary_def_path)] fn init_default_impl_for_type_if_needed(&mut self, cx: &LateContext<'_>) { if self.default_impl_for_type.is_empty() - && let Some(default_trait_id) = get_trait_def_id(cx, &["core", "default", "Default"]) + && let Some(default_trait_id) = cx.tcx.get_diagnostic_item(sym::Default) { let impls = cx.tcx.trait_impls_of(default_trait_id); for (ty, impl_def_ids) in impls.non_blanket_impls() { @@ -394,6 +391,34 @@ impl UnconditionalRecursion { } } +fn check_from(cx: &LateContext<'_>, method_span: Span, method_def_id: LocalDefId, expr: &Expr<'_>) { + let Some(sig) = cx + .typeck_results() + .liberated_fn_sigs() + .get(cx.tcx.local_def_id_to_hir_id(method_def_id)) + else { + return; + }; + + // Check if we are calling `Into::into` where the node args match with our `From::from` signature: + // From::from signature: fn(S1) -> S2 + // <S1 as Into<S2>>::into(s1), node_args=[S1, S2] + // If they do match, then it must mean that it is the blanket impl, + // which calls back into our `From::from` again (`Into` is not specializable). + // rustc's unconditional_recursion already catches calling `From::from` directly + if let Some((fn_def_id, node_args)) = fn_def_id_with_node_args(cx, expr) + && let [s1, s2] = **node_args + && let (Some(s1), Some(s2)) = (s1.as_type(), s2.as_type()) + && let Some(trait_def_id) = cx.tcx.trait_of_item(fn_def_id) + && cx.tcx.is_diagnostic_item(sym::Into, trait_def_id) + && get_impl_trait_def_id(cx, method_def_id) == cx.tcx.get_diagnostic_item(sym::From) + && s1 == sig.inputs()[0] + && s2 == sig.output() + { + span_error(cx, method_span, expr); + } +} + impl<'tcx> LateLintPass<'tcx> for UnconditionalRecursion { fn check_fn( &mut self, @@ -410,10 +435,11 @@ impl<'tcx> LateLintPass<'tcx> for UnconditionalRecursion { // Doesn't have a conditional return. && !has_conditional_return(body, expr) { - if name.name == sym::eq || name.name == sym::ne { - check_partial_eq(cx, method_span, method_def_id, name, expr); - } else if name.name == sym::to_string { - check_to_string(cx, method_span, method_def_id, name, expr); + match name.name { + sym::eq | sym::ne => check_partial_eq(cx, method_span, method_def_id, name, expr), + sym::to_string => check_to_string(cx, method_span, method_def_id, name, expr), + sym::from => check_from(cx, method_span, method_def_id, expr), + _ => {}, } self.check_default_new(cx, decl, body, method_span, method_def_id); } diff --git a/clippy_lints/src/unused_io_amount.rs b/clippy_lints/src/unused_io_amount.rs index eb64dd633f6..17a5c881c3b 100644 --- a/clippy_lints/src/unused_io_amount.rs +++ b/clippy_lints/src/unused_io_amount.rs @@ -1,7 +1,7 @@ -use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::diagnostics::span_lint_hir_and_then; use clippy_utils::macros::{is_panic, root_macro_call_first_node}; use clippy_utils::{is_res_lang_ctor, is_trait_method, match_trait_method, paths, peel_blocks}; -use hir::{ExprKind, PatKind}; +use hir::{ExprKind, HirId, PatKind}; use rustc_hir as hir; use rustc_lint::{LateContext, LateLintPass}; use rustc_session::declare_lint_pass; @@ -135,22 +135,22 @@ fn check_expr<'a>(cx: &LateContext<'a>, expr: &'a hir::Expr<'a>) { && is_ok_wild_or_dotdot_pattern(cx, pat) && let Some(op) = should_lint(cx, init) => { - emit_lint(cx, cond.span, op, &[pat.span]); + emit_lint(cx, cond.span, cond.hir_id, op, &[pat.span]); }, // we will capture only the case where the match is Ok( ) or Err( ) // prefer to match the minimum possible, and expand later if needed // to avoid false positives on something as used as this hir::ExprKind::Match(expr, [arm1, arm2], hir::MatchSource::Normal) if let Some(op) = should_lint(cx, expr) => { if non_consuming_ok_arm(cx, arm1) && non_consuming_err_arm(cx, arm2) { - emit_lint(cx, expr.span, op, &[arm1.pat.span]); + emit_lint(cx, expr.span, expr.hir_id, op, &[arm1.pat.span]); } if non_consuming_ok_arm(cx, arm2) && non_consuming_err_arm(cx, arm1) { - emit_lint(cx, expr.span, op, &[arm2.pat.span]); + emit_lint(cx, expr.span, expr.hir_id, op, &[arm2.pat.span]); } }, hir::ExprKind::Match(_, _, hir::MatchSource::Normal) => {}, _ if let Some(op) = should_lint(cx, expr) => { - emit_lint(cx, expr.span, op, &[]); + emit_lint(cx, expr.span, expr.hir_id, op, &[]); }, _ => {}, }; @@ -279,7 +279,7 @@ fn check_io_mode(cx: &LateContext<'_>, call: &hir::Expr<'_>) -> Option<IoOp> { } } -fn emit_lint(cx: &LateContext<'_>, span: Span, op: IoOp, wild_cards: &[Span]) { +fn emit_lint(cx: &LateContext<'_>, span: Span, at: HirId, op: IoOp, wild_cards: &[Span]) { let (msg, help) = match op { IoOp::AsyncRead(false) => ( "read amount is not handled", @@ -301,7 +301,7 @@ fn emit_lint(cx: &LateContext<'_>, span: Span, op: IoOp, wild_cards: &[Span]) { IoOp::SyncWrite(true) | IoOp::AsyncWrite(true) => ("written amount is not handled", None), }; - span_lint_and_then(cx, UNUSED_IO_AMOUNT, span, msg, |diag| { + span_lint_hir_and_then(cx, UNUSED_IO_AMOUNT, at, span, msg, |diag| { if let Some(help_str) = help { diag.help(help_str); } diff --git a/clippy_lints/src/unused_peekable.rs b/clippy_lints/src/unused_peekable.rs index f1d0c22b1ae..3f4ab3e31cf 100644 --- a/clippy_lints/src/unused_peekable.rs +++ b/clippy_lints/src/unused_peekable.rs @@ -1,4 +1,4 @@ -use clippy_utils::diagnostics::span_lint_and_help; +use clippy_utils::diagnostics::span_lint_hir_and_then; use clippy_utils::ty::{is_type_diagnostic_item, peel_mid_ty_refs_is_mutable}; use clippy_utils::{fn_def_id, is_trait_method, path_to_local_id, peel_ref_operators}; use rustc_ast::Mutability; @@ -79,13 +79,15 @@ impl<'tcx> LateLintPass<'tcx> for UnusedPeekable { } if !vis.found_peek_call { - span_lint_and_help( + span_lint_hir_and_then( cx, UNUSED_PEEKABLE, + local.hir_id, ident.span, "`peek` never called on `Peekable` iterator", - None, - "consider removing the call to `peekable`", + |diag| { + diag.help("consider removing the call to `peekable`"); + }, ); } } diff --git a/clippy_lints/src/use_self.rs b/clippy_lints/src/use_self.rs index a1b08d105b9..b28037db112 100644 --- a/clippy_lints/src/use_self.rs +++ b/clippy_lints/src/use_self.rs @@ -8,11 +8,12 @@ use rustc_hir::def::{CtorOf, DefKind, Res}; use rustc_hir::def_id::LocalDefId; use rustc_hir::intravisit::{walk_inf, walk_ty, Visitor}; use rustc_hir::{ - self as hir, Expr, ExprKind, FnRetTy, FnSig, GenericArg, GenericArgsParentheses, GenericParam, GenericParamKind, - HirId, Impl, ImplItemKind, Item, ItemKind, Pat, PatKind, Path, QPath, Ty, TyKind, + self as hir, Expr, ExprKind, FnRetTy, FnSig, GenericArgsParentheses, GenericParam, GenericParamKind, HirId, Impl, + ImplItemKind, Item, ItemKind, Pat, PatKind, Path, QPath, Ty, TyKind, }; use rustc_hir_analysis::hir_ty_to_ty; use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::ty::Ty as MiddleTy; use rustc_session::impl_lint_pass; use rustc_span::Span; @@ -95,10 +96,9 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf { let stack_item = if let ItemKind::Impl(Impl { self_ty, generics, .. }) = item.kind && let TyKind::Path(QPath::Resolved(_, item_path)) = self_ty.kind && let parameters = &item_path.segments.last().expect(SEGMENTS_MSG).args - && parameters.as_ref().map_or(true, |params| { - params.parenthesized == GenericArgsParentheses::No - && !params.args.iter().any(|arg| matches!(arg, GenericArg::Lifetime(_))) - }) + && parameters + .as_ref() + .map_or(true, |params| params.parenthesized == GenericArgsParentheses::No) && !item.span.from_expansion() && !is_from_proc_macro(cx, item) // expensive, should be last check @@ -226,7 +226,12 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf { } else { hir_ty_to_ty(cx.tcx, hir_ty) } - && same_type_and_consts(ty, cx.tcx.type_of(impl_id).instantiate_identity()) + && let impl_ty = cx.tcx.type_of(impl_id).instantiate_identity() + && same_type_and_consts(ty, impl_ty) + // Ensure the type we encounter and the one from the impl have the same lifetime parameters. It may be that + // the lifetime parameters of `ty` are ellided (`impl<'a> Foo<'a> { fn new() -> Self { Foo{..} } }`, in + // which case we must still trigger the lint. + && (has_no_lifetime(ty) || same_lifetimes(ty, impl_ty)) { span_lint(cx, hir_ty.span); } @@ -318,3 +323,37 @@ fn lint_path_to_variant(cx: &LateContext<'_>, path: &Path<'_>) { span_lint(cx, span); } } + +/// Returns `true` if types `a` and `b` have the same lifetime parameters, otherwise returns +/// `false`. +/// +/// This function does not check that types `a` and `b` are the same types. +fn same_lifetimes<'tcx>(a: MiddleTy<'tcx>, b: MiddleTy<'tcx>) -> bool { + use rustc_middle::ty::{Adt, GenericArgKind}; + match (&a.kind(), &b.kind()) { + (&Adt(_, args_a), &Adt(_, args_b)) => { + args_a + .iter() + .zip(args_b.iter()) + .all(|(arg_a, arg_b)| match (arg_a.unpack(), arg_b.unpack()) { + // TODO: Handle inferred lifetimes + (GenericArgKind::Lifetime(inner_a), GenericArgKind::Lifetime(inner_b)) => inner_a == inner_b, + (GenericArgKind::Type(type_a), GenericArgKind::Type(type_b)) => same_lifetimes(type_a, type_b), + _ => true, + }) + }, + _ => a == b, + } +} + +/// Returns `true` if `ty` has no lifetime parameter, otherwise returns `false`. +fn has_no_lifetime(ty: MiddleTy<'_>) -> bool { + use rustc_middle::ty::{Adt, GenericArgKind}; + match ty.kind() { + &Adt(_, args) => !args + .iter() + // TODO: Handle inferred lifetimes + .any(|arg| matches!(arg.unpack(), GenericArgKind::Lifetime(..))), + _ => true, + } +} diff --git a/clippy_lints/src/utils/internal_lints/metadata_collector.rs b/clippy_lints/src/utils/internal_lints/metadata_collector.rs index 97b509a84f9..1ebe1d6a2c4 100644 --- a/clippy_lints/src/utils/internal_lints/metadata_collector.rs +++ b/clippy_lints/src/utils/internal_lints/metadata_collector.rs @@ -925,7 +925,7 @@ impl<'a, 'hir> intravisit::Visitor<'hir> for LintResolver<'a, 'hir> { && let (expr_ty, _) = walk_ptrs_ty_depth(self.cx.typeck_results().expr_ty(expr)) && match_type(self.cx, expr_ty, &paths::LINT) { - if let hir::def::Res::Def(DefKind::Static(..), _) = path.res { + if let hir::def::Res::Def(DefKind::Static { .. }, _) = path.res { let lint_name = last_path_segment(qpath).ident.name; self.lints.push(sym_to_string(lint_name).to_ascii_lowercase()); } else if let Some(local) = get_parent_local(self.cx, expr) { diff --git a/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs b/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs index 38c832931fc..f4e277fd0c4 100644 --- a/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs +++ b/clippy_lints/src/utils/internal_lints/unnecessary_def_path.rs @@ -223,7 +223,7 @@ fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<Ve None } }, - Res::Def(DefKind::Static(_), def_id) => read_mir_alloc_def_path( + Res::Def(DefKind::Static { .. }, def_id) => read_mir_alloc_def_path( cx, cx.tcx.eval_static_initializer(def_id).ok()?.inner(), cx.tcx.type_of(def_id).instantiate_identity(), diff --git a/clippy_lints/src/wildcard_imports.rs b/clippy_lints/src/wildcard_imports.rs index 5410e8ac117..436f0cb79fb 100644 --- a/clippy_lints/src/wildcard_imports.rs +++ b/clippy_lints/src/wildcard_imports.rs @@ -213,7 +213,7 @@ fn is_super_only_import(segments: &[PathSegment<'_>]) -> bool { // Allow skipping imports containing user configured segments, // i.e. "...::utils::...::*" if user put `allowed-wildcard-imports = ["utils"]` in `Clippy.toml` fn is_allowed_via_config(segments: &[PathSegment<'_>], allowed_segments: &FxHashSet<String>) -> bool { - // segment matching need to be exact instead of using 'contains', in case user unintentionaly put + // segment matching need to be exact instead of using 'contains', in case user unintentionally put // a single character in the config thus skipping most of the warnings. segments.iter().any(|seg| allowed_segments.contains(seg.ident.as_str())) } diff --git a/clippy_lints/src/zero_repeat_side_effects.rs b/clippy_lints/src/zero_repeat_side_effects.rs new file mode 100644 index 00000000000..852d04cd21b --- /dev/null +++ b/clippy_lints/src/zero_repeat_side_effects.rs @@ -0,0 +1,154 @@ +use clippy_utils::diagnostics::span_lint_and_sugg; +use clippy_utils::higher::VecArgs; +use clippy_utils::source::snippet; +use clippy_utils::visitors::for_each_expr; +use rustc_ast::LitKind; +use rustc_errors::Applicability; +use rustc_hir::{ExprKind, Node}; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::ty::{self, ConstKind, Ty}; +use rustc_session::declare_lint_pass; +use rustc_span::Span; + +declare_clippy_lint! { + /// ### What it does + /// Checks for array or vec initializations which call a function or method, + /// but which have a repeat count of zero. + /// + /// ### Why is this bad? + /// Such an initialization, despite having a repeat length of 0, will still call the inner function. + /// This may not be obvious and as such there may be unintended side effects in code. + /// + /// ### Example + /// ```no_run + /// fn side_effect() -> i32 { + /// println!("side effect"); + /// 10 + /// } + /// let a = [side_effect(); 0]; + /// ``` + /// Use instead: + /// ```no_run + /// fn side_effect() -> i32 { + /// println!("side effect"); + /// 10 + /// } + /// side_effect(); + /// let a: [i32; 0] = []; + /// ``` + #[clippy::version = "1.75.0"] + pub ZERO_REPEAT_SIDE_EFFECTS, + suspicious, + "usage of zero-sized initializations of arrays or vecs causing side effects" +} + +declare_lint_pass!(ZeroRepeatSideEffects => [ZERO_REPEAT_SIDE_EFFECTS]); + +impl LateLintPass<'_> for ZeroRepeatSideEffects { + fn check_expr(&mut self, cx: &LateContext<'_>, expr: &'_ rustc_hir::Expr<'_>) { + if let Some(args) = VecArgs::hir(cx, expr) + && let VecArgs::Repeat(inner_expr, len) = args + && let ExprKind::Lit(l) = len.kind + && let LitKind::Int(i, _) = l.node + && i.0 == 0 + { + inner_check(cx, expr, inner_expr, true); + } else if let ExprKind::Repeat(inner_expr, _) = expr.kind + && let ty::Array(_, cst) = cx.typeck_results().expr_ty(expr).kind() + && let ConstKind::Value(ty::ValTree::Leaf(element_count)) = cst.kind() + && let Ok(element_count) = element_count.try_to_target_usize(cx.tcx) + && element_count == 0 + { + inner_check(cx, expr, inner_expr, false); + } + } +} + +fn inner_check(cx: &LateContext<'_>, expr: &'_ rustc_hir::Expr<'_>, inner_expr: &'_ rustc_hir::Expr<'_>, is_vec: bool) { + // check if expr is a call or has a call inside it + if for_each_expr(inner_expr, |x| { + if let ExprKind::Call(_, _) | ExprKind::MethodCall(_, _, _, _) = x.kind { + std::ops::ControlFlow::Break(()) + } else { + std::ops::ControlFlow::Continue(()) + } + }) + .is_some() + { + let parent_hir_node = cx.tcx.parent_hir_node(expr.hir_id); + let return_type = cx.typeck_results().expr_ty(expr); + + if let Node::Local(l) = parent_hir_node { + array_span_lint( + cx, + l.span, + inner_expr.span, + l.pat.span, + Some(return_type), + is_vec, + false, + ); + } else if let Node::Expr(x) = parent_hir_node + && let ExprKind::Assign(l, _, _) = x.kind + { + array_span_lint(cx, x.span, inner_expr.span, l.span, Some(return_type), is_vec, true); + } else { + span_lint_and_sugg( + cx, + ZERO_REPEAT_SIDE_EFFECTS, + expr.span.source_callsite(), + "function or method calls as the initial value in zero-sized array initializers may cause side effects", + "consider using", + format!( + "{{ {}; {}[] as {return_type} }}", + snippet(cx, inner_expr.span.source_callsite(), ".."), + if is_vec { "vec!" } else { "" }, + ), + Applicability::Unspecified, + ); + } + } +} + +fn array_span_lint( + cx: &LateContext<'_>, + expr_span: Span, + func_call_span: Span, + variable_name_span: Span, + expr_ty: Option<Ty<'_>>, + is_vec: bool, + is_assign: bool, +) { + let has_ty = expr_ty.is_some(); + + span_lint_and_sugg( + cx, + ZERO_REPEAT_SIDE_EFFECTS, + expr_span.source_callsite(), + "function or method calls as the initial value in zero-sized array initializers may cause side effects", + "consider using", + format!( + "{}; {}{}{} = {}[]{}{}", + snippet(cx, func_call_span.source_callsite(), ".."), + if has_ty && !is_assign { "let " } else { "" }, + snippet(cx, variable_name_span.source_callsite(), ".."), + if let Some(ty) = expr_ty + && !is_assign + { + format!(": {ty}") + } else { + String::new() + }, + if is_vec { "vec!" } else { "" }, + if let Some(ty) = expr_ty + && is_assign + { + format!(" as {ty}") + } else { + String::new() + }, + if is_assign { "" } else { ";" } + ), + Applicability::Unspecified, + ); +} |
