diff options
Diffstat (limited to 'clippy_lints/src/utils/internal_lints.rs')
| -rw-r--r-- | clippy_lints/src/utils/internal_lints.rs | 1576 |
1 files changed, 11 insertions, 1565 deletions
diff --git a/clippy_lints/src/utils/internal_lints.rs b/clippy_lints/src/utils/internal_lints.rs index 85bcbc7ad23..71f6c9909dd 100644 --- a/clippy_lints/src/utils/internal_lints.rs +++ b/clippy_lints/src/utils/internal_lints.rs @@ -1,1566 +1,12 @@ -use crate::utils::internal_lints::metadata_collector::is_deprecated_lint; -use clippy_utils::consts::{constant_simple, Constant}; -use clippy_utils::diagnostics::{span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then}; -use clippy_utils::macros::root_macro_call_first_node; -use clippy_utils::source::{snippet, snippet_with_applicability}; -use clippy_utils::ty::match_type; -use clippy_utils::{ - def_path_res, higher, is_else_clause, is_expn_of, is_expr_path_def_path, is_lint_allowed, match_any_def_paths, - match_def_path, method_calls, paths, peel_blocks_with_stmt, peel_hir_expr_refs, SpanlessEq, -}; -use if_chain::if_chain; -use rustc_ast as ast; -use rustc_ast::ast::{Crate, ItemKind, LitKind, ModKind, NodeId}; -use rustc_ast::visit::FnKind; -use rustc_data_structures::fx::{FxHashMap, FxHashSet}; -use rustc_errors::Applicability; -use rustc_hir as hir; -use rustc_hir::def::{DefKind, Namespace, Res}; -use rustc_hir::def_id::DefId; -use rustc_hir::hir_id::CRATE_HIR_ID; -use rustc_hir::intravisit::Visitor; -use rustc_hir::{ - BinOpKind, Block, Closure, Expr, ExprKind, HirId, Item, Local, MutTy, Mutability, Node, Path, Stmt, StmtKind, - TyKind, UnOp, -}; -use rustc_hir_analysis::hir_ty_to_ty; -use rustc_lint::{EarlyContext, EarlyLintPass, LateContext, LateLintPass, LintContext}; -use rustc_middle::hir::nested_filter; -use rustc_middle::mir::interpret::{Allocation, ConstValue, GlobalAlloc}; -use rustc_middle::ty::{ - self, fast_reject::SimplifiedTypeGen, subst::GenericArgKind, AssocKind, DefIdTree, FloatTy, Ty, -}; -use rustc_semver::RustcVersion; -use rustc_session::{declare_lint_pass, declare_tool_lint, impl_lint_pass}; -use rustc_span::source_map::Spanned; -use rustc_span::symbol::{Ident, Symbol}; -use rustc_span::{sym, BytePos, Span}; - -use std::borrow::{Borrow, Cow}; -use std::str; - -#[cfg(feature = "internal")] +pub mod clippy_lints_internal; +pub mod collapsible_calls; +pub mod compiler_lint_functions; +pub mod if_chain_style; +pub mod interning_defined_symbol; +pub mod invalid_paths; +pub mod lint_without_lint_pass; pub mod metadata_collector; - -declare_clippy_lint! { - /// ### What it does - /// Checks for various things we like to keep tidy in clippy. - /// - /// ### Why is this bad? - /// We like to pretend we're an example of tidy code. - /// - /// ### Example - /// Wrong ordering of the util::paths constants. - pub CLIPPY_LINTS_INTERNAL, - internal, - "various things that will negatively affect your clippy experience" -} - -declare_clippy_lint! { - /// ### What it does - /// Ensures every lint is associated to a `LintPass`. - /// - /// ### Why is this bad? - /// The compiler only knows lints via a `LintPass`. Without - /// putting a lint to a `LintPass::get_lints()`'s return, the compiler will not - /// know the name of the lint. - /// - /// ### Known problems - /// Only checks for lints associated using the - /// `declare_lint_pass!`, `impl_lint_pass!`, and `lint_array!` macros. - /// - /// ### Example - /// ```rust,ignore - /// declare_lint! { pub LINT_1, ... } - /// declare_lint! { pub LINT_2, ... } - /// declare_lint! { pub FORGOTTEN_LINT, ... } - /// // ... - /// declare_lint_pass!(Pass => [LINT_1, LINT_2]); - /// // missing FORGOTTEN_LINT - /// ``` - pub LINT_WITHOUT_LINT_PASS, - internal, - "declaring a lint without associating it in a LintPass" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for calls to `cx.span_lint*` and suggests to use the `utils::*` - /// variant of the function. - /// - /// ### Why is this bad? - /// The `utils::*` variants also add a link to the Clippy documentation to the - /// warning/error messages. - /// - /// ### Example - /// ```rust,ignore - /// cx.span_lint(LINT_NAME, "message"); - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// utils::span_lint(cx, LINT_NAME, "message"); - /// ``` - pub COMPILER_LINT_FUNCTIONS, - internal, - "usage of the lint functions of the compiler instead of the utils::* variant" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for calls to `cx.outer().expn_data()` and suggests to use - /// the `cx.outer_expn_data()` - /// - /// ### Why is this bad? - /// `cx.outer_expn_data()` is faster and more concise. - /// - /// ### Example - /// ```rust,ignore - /// expr.span.ctxt().outer().expn_data() - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// expr.span.ctxt().outer_expn_data() - /// ``` - pub OUTER_EXPN_EXPN_DATA, - internal, - "using `cx.outer_expn().expn_data()` instead of `cx.outer_expn_data()`" -} - -declare_clippy_lint! { - /// ### What it does - /// Not an actual lint. This lint is only meant for testing our customized internal compiler - /// error message by calling `panic`. - /// - /// ### Why is this bad? - /// ICE in large quantities can damage your teeth - /// - /// ### Example - /// ```rust,ignore - /// 🍦🍦🍦🍦🍦 - /// ``` - pub PRODUCE_ICE, - internal, - "this message should not appear anywhere as we ICE before and don't emit the lint" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for cases of an auto-generated lint without an updated description, - /// i.e. `default lint description`. - /// - /// ### Why is this bad? - /// Indicates that the lint is not finished. - /// - /// ### Example - /// ```rust,ignore - /// declare_lint! { pub COOL_LINT, nursery, "default lint description" } - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// declare_lint! { pub COOL_LINT, nursery, "a great new lint" } - /// ``` - pub DEFAULT_LINT, - internal, - "found 'default lint description' in a lint declaration" -} - -declare_clippy_lint! { - /// ### What it does - /// Lints `span_lint_and_then` function calls, where the - /// closure argument has only one statement and that statement is a method - /// call to `span_suggestion`, `span_help`, `span_note` (using the same - /// span), `help` or `note`. - /// - /// These usages of `span_lint_and_then` should be replaced with one of the - /// wrapper functions `span_lint_and_sugg`, span_lint_and_help`, or - /// `span_lint_and_note`. - /// - /// ### Why is this bad? - /// Using the wrapper `span_lint_and_*` functions, is more - /// convenient, readable and less error prone. - /// - /// ### Example - /// ```rust,ignore - /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| { - /// diag.span_suggestion( - /// expr.span, - /// help_msg, - /// sugg.to_string(), - /// Applicability::MachineApplicable, - /// ); - /// }); - /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| { - /// diag.span_help(expr.span, help_msg); - /// }); - /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| { - /// diag.help(help_msg); - /// }); - /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| { - /// diag.span_note(expr.span, note_msg); - /// }); - /// span_lint_and_then(cx, TEST_LINT, expr.span, lint_msg, |diag| { - /// diag.note(note_msg); - /// }); - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// span_lint_and_sugg( - /// cx, - /// TEST_LINT, - /// expr.span, - /// lint_msg, - /// help_msg, - /// sugg.to_string(), - /// Applicability::MachineApplicable, - /// ); - /// span_lint_and_help(cx, TEST_LINT, expr.span, lint_msg, Some(expr.span), help_msg); - /// span_lint_and_help(cx, TEST_LINT, expr.span, lint_msg, None, help_msg); - /// span_lint_and_note(cx, TEST_LINT, expr.span, lint_msg, Some(expr.span), note_msg); - /// span_lint_and_note(cx, TEST_LINT, expr.span, lint_msg, None, note_msg); - /// ``` - pub COLLAPSIBLE_SPAN_LINT_CALLS, - internal, - "found collapsible `span_lint_and_then` calls" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for usages of def paths when a diagnostic item or a `LangItem` could be used. - /// - /// ### Why is this bad? - /// The path for an item is subject to change and is less efficient to look up than a - /// diagnostic item or a `LangItem`. - /// - /// ### Example - /// ```rust,ignore - /// utils::match_type(cx, ty, &paths::VEC) - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// utils::is_type_diagnostic_item(cx, ty, sym::Vec) - /// ``` - pub UNNECESSARY_DEF_PATH, - internal, - "using a def path when a diagnostic item or a `LangItem` is available" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks the paths module for invalid paths. - /// - /// ### Why is this bad? - /// It indicates a bug in the code. - /// - /// ### Example - /// None. - pub INVALID_PATHS, - internal, - "invalid path" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for interning symbols that have already been pre-interned and defined as constants. - /// - /// ### Why is this bad? - /// It's faster and easier to use the symbol constant. - /// - /// ### Example - /// ```rust,ignore - /// let _ = sym!(f32); - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// let _ = sym::f32; - /// ``` - pub INTERNING_DEFINED_SYMBOL, - internal, - "interning a symbol that is pre-interned and defined as a constant" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for unnecessary conversion from Symbol to a string. - /// - /// ### Why is this bad? - /// It's faster use symbols directly instead of strings. - /// - /// ### Example - /// ```rust,ignore - /// symbol.as_str() == "clippy"; - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// symbol == sym::clippy; - /// ``` - pub UNNECESSARY_SYMBOL_STR, - internal, - "unnecessary conversion between Symbol and string" -} - -declare_clippy_lint! { - /// Finds unidiomatic usage of `if_chain!` - pub IF_CHAIN_STYLE, - internal, - "non-idiomatic `if_chain!` usage" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for invalid `clippy::version` attributes. - /// - /// Valid values are: - /// * "pre 1.29.0" - /// * any valid semantic version - pub INVALID_CLIPPY_VERSION_ATTRIBUTE, - internal, - "found an invalid `clippy::version` attribute" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for declared clippy lints without the `clippy::version` attribute. - /// - pub MISSING_CLIPPY_VERSION_ATTRIBUTE, - internal, - "found clippy lint without `clippy::version` attribute" -} - -declare_clippy_lint! { - /// ### What it does - /// Check that the `extract_msrv_attr!` macro is used, when a lint has a MSRV. - /// - pub MISSING_MSRV_ATTR_IMPL, - internal, - "checking if all necessary steps were taken when adding a MSRV to a lint" -} - -declare_clippy_lint! { - /// ### What it does - /// Checks for cases of an auto-generated deprecated lint without an updated reason, - /// i.e. `"default deprecation note"`. - /// - /// ### Why is this bad? - /// Indicates that the documentation is incomplete. - /// - /// ### Example - /// ```rust,ignore - /// declare_deprecated_lint! { - /// /// ### What it does - /// /// Nothing. This lint has been deprecated. - /// /// - /// /// ### Deprecation reason - /// /// TODO - /// #[clippy::version = "1.63.0"] - /// pub COOL_LINT, - /// "default deprecation note" - /// } - /// ``` - /// - /// Use instead: - /// ```rust,ignore - /// declare_deprecated_lint! { - /// /// ### What it does - /// /// Nothing. This lint has been deprecated. - /// /// - /// /// ### Deprecation reason - /// /// This lint has been replaced by `cooler_lint` - /// #[clippy::version = "1.63.0"] - /// pub COOL_LINT, - /// "this lint has been replaced by `cooler_lint`" - /// } - /// ``` - pub DEFAULT_DEPRECATION_REASON, - internal, - "found 'default deprecation note' in a deprecated lint declaration" -} - -declare_lint_pass!(ClippyLintsInternal => [CLIPPY_LINTS_INTERNAL]); - -impl EarlyLintPass for ClippyLintsInternal { - fn check_crate(&mut self, cx: &EarlyContext<'_>, krate: &Crate) { - if let Some(utils) = krate.items.iter().find(|item| item.ident.name.as_str() == "utils") { - if let ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) = utils.kind { - if let Some(paths) = items.iter().find(|item| item.ident.name.as_str() == "paths") { - if let ItemKind::Mod(_, ModKind::Loaded(ref items, ..)) = paths.kind { - let mut last_name: Option<&str> = None; - for item in items { - let name = item.ident.as_str(); - if let Some(last_name) = last_name { - if *last_name > *name { - span_lint( - cx, - CLIPPY_LINTS_INTERNAL, - item.span, - "this constant should be before the previous constant due to lexical \ - ordering", - ); - } - } - last_name = Some(name); - } - } - } - } - } - } -} - -#[derive(Clone, Debug, Default)] -pub struct LintWithoutLintPass { - declared_lints: FxHashMap<Symbol, Span>, - registered_lints: FxHashSet<Symbol>, -} - -impl_lint_pass!(LintWithoutLintPass => [DEFAULT_LINT, LINT_WITHOUT_LINT_PASS, INVALID_CLIPPY_VERSION_ATTRIBUTE, MISSING_CLIPPY_VERSION_ATTRIBUTE, DEFAULT_DEPRECATION_REASON]); - -impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass { - fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) { - if is_lint_allowed(cx, DEFAULT_LINT, item.hir_id()) - || is_lint_allowed(cx, DEFAULT_DEPRECATION_REASON, item.hir_id()) - { - return; - } - - if let hir::ItemKind::Static(ty, Mutability::Not, body_id) = item.kind { - let is_lint_ref_ty = is_lint_ref_type(cx, ty); - if is_deprecated_lint(cx, ty) || is_lint_ref_ty { - check_invalid_clippy_version_attribute(cx, item); - - let expr = &cx.tcx.hir().body(body_id).value; - let fields; - if is_lint_ref_ty { - if let ExprKind::AddrOf(_, _, inner_exp) = expr.kind - && let ExprKind::Struct(_, struct_fields, _) = inner_exp.kind { - fields = struct_fields; - } else { - return; - } - } else if let ExprKind::Struct(_, struct_fields, _) = expr.kind { - fields = struct_fields; - } else { - return; - } - - let field = fields - .iter() - .find(|f| f.ident.as_str() == "desc") - .expect("lints must have a description field"); - - if let ExprKind::Lit(Spanned { - node: LitKind::Str(ref sym, _), - .. - }) = field.expr.kind - { - let sym_str = sym.as_str(); - if is_lint_ref_ty { - if sym_str == "default lint description" { - span_lint( - cx, - DEFAULT_LINT, - item.span, - &format!("the lint `{}` has the default lint description", item.ident.name), - ); - } - - self.declared_lints.insert(item.ident.name, item.span); - } else if sym_str == "default deprecation note" { - span_lint( - cx, - DEFAULT_DEPRECATION_REASON, - item.span, - &format!("the lint `{}` has the default deprecation reason", item.ident.name), - ); - } - } - } - } else if let Some(macro_call) = root_macro_call_first_node(cx, item) { - if !matches!( - cx.tcx.item_name(macro_call.def_id).as_str(), - "impl_lint_pass" | "declare_lint_pass" - ) { - return; - } - if let hir::ItemKind::Impl(hir::Impl { - of_trait: None, - items: impl_item_refs, - .. - }) = item.kind - { - let mut collector = LintCollector { - output: &mut self.registered_lints, - cx, - }; - let body_id = cx.tcx.hir().body_owned_by( - cx.tcx.hir().local_def_id( - impl_item_refs - .iter() - .find(|iiref| iiref.ident.as_str() == "get_lints") - .expect("LintPass needs to implement get_lints") - .id - .hir_id(), - ), - ); - collector.visit_expr(cx.tcx.hir().body(body_id).value); - } - } - } - - fn check_crate_post(&mut self, cx: &LateContext<'tcx>) { - if is_lint_allowed(cx, LINT_WITHOUT_LINT_PASS, CRATE_HIR_ID) { - return; - } - - for (lint_name, &lint_span) in &self.declared_lints { - // When using the `declare_tool_lint!` macro, the original `lint_span`'s - // file points to "<rustc macros>". - // `compiletest-rs` thinks that's an error in a different file and - // just ignores it. This causes the test in compile-fail/lint_pass - // not able to capture the error. - // Therefore, we need to climb the macro expansion tree and find the - // actual span that invoked `declare_tool_lint!`: - let lint_span = lint_span.ctxt().outer_expn_data().call_site; - - if !self.registered_lints.contains(lint_name) { - span_lint( - cx, - LINT_WITHOUT_LINT_PASS, - lint_span, - &format!("the lint `{lint_name}` is not added to any `LintPass`"), - ); - } - } - } -} - -fn is_lint_ref_type<'tcx>(cx: &LateContext<'tcx>, ty: &hir::Ty<'_>) -> bool { - if let TyKind::Rptr( - _, - MutTy { - ty: inner, - mutbl: Mutability::Not, - }, - ) = ty.kind - { - if let TyKind::Path(ref path) = inner.kind { - if let Res::Def(DefKind::Struct, def_id) = cx.qpath_res(path, inner.hir_id) { - return match_def_path(cx, def_id, &paths::LINT); - } - } - } - - false -} - -fn check_invalid_clippy_version_attribute(cx: &LateContext<'_>, item: &'_ Item<'_>) { - if let Some(value) = extract_clippy_version_value(cx, item) { - // The `sym!` macro doesn't work as it only expects a single token. - // It's better to keep it this way and have a direct `Symbol::intern` call here. - if value == Symbol::intern("pre 1.29.0") { - return; - } - - if RustcVersion::parse(value.as_str()).is_err() { - span_lint_and_help( - cx, - INVALID_CLIPPY_VERSION_ATTRIBUTE, - item.span, - "this item has an invalid `clippy::version` attribute", - None, - "please use a valid semantic version, see `doc/adding_lints.md`", - ); - } - } else { - span_lint_and_help( - cx, - MISSING_CLIPPY_VERSION_ATTRIBUTE, - item.span, - "this lint is missing the `clippy::version` attribute or version value", - None, - "please use a `clippy::version` attribute, see `doc/adding_lints.md`", - ); - } -} - -/// This function extracts the version value of a `clippy::version` attribute if the given value has -/// one -fn extract_clippy_version_value(cx: &LateContext<'_>, item: &'_ Item<'_>) -> Option<Symbol> { - let attrs = cx.tcx.hir().attrs(item.hir_id()); - attrs.iter().find_map(|attr| { - if_chain! { - // Identify attribute - if let ast::AttrKind::Normal(ref attr_kind) = &attr.kind; - if let [tool_name, attr_name] = &attr_kind.item.path.segments[..]; - if tool_name.ident.name == sym::clippy; - if attr_name.ident.name == sym::version; - if let Some(version) = attr.value_str(); - then { - Some(version) - } else { - None - } - } - }) -} - -struct LintCollector<'a, 'tcx> { - output: &'a mut FxHashSet<Symbol>, - cx: &'a LateContext<'tcx>, -} - -impl<'a, 'tcx> Visitor<'tcx> for LintCollector<'a, 'tcx> { - type NestedFilter = nested_filter::All; - - fn visit_path(&mut self, path: &'tcx Path<'_>, _: HirId) { - if path.segments.len() == 1 { - self.output.insert(path.segments[0].ident.name); - } - } - - fn nested_visit_map(&mut self) -> Self::Map { - self.cx.tcx.hir() - } -} - -#[derive(Clone, Default)] -pub struct CompilerLintFunctions { - map: FxHashMap<&'static str, &'static str>, -} - -impl CompilerLintFunctions { - #[must_use] - pub fn new() -> Self { - let mut map = FxHashMap::default(); - map.insert("span_lint", "utils::span_lint"); - map.insert("struct_span_lint", "utils::span_lint"); - map.insert("lint", "utils::span_lint"); - map.insert("span_lint_note", "utils::span_lint_and_note"); - map.insert("span_lint_help", "utils::span_lint_and_help"); - Self { map } - } -} - -impl_lint_pass!(CompilerLintFunctions => [COMPILER_LINT_FUNCTIONS]); - -impl<'tcx> LateLintPass<'tcx> for CompilerLintFunctions { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if is_lint_allowed(cx, COMPILER_LINT_FUNCTIONS, expr.hir_id) { - return; - } - - if_chain! { - if let ExprKind::MethodCall(path, self_arg, _, _) = &expr.kind; - let fn_name = path.ident; - if let Some(sugg) = self.map.get(fn_name.as_str()); - let ty = cx.typeck_results().expr_ty(self_arg).peel_refs(); - if match_type(cx, ty, &paths::EARLY_CONTEXT) - || match_type(cx, ty, &paths::LATE_CONTEXT); - then { - span_lint_and_help( - cx, - COMPILER_LINT_FUNCTIONS, - path.ident.span, - "usage of a compiler lint function", - None, - &format!("please use the Clippy variant of this function: `{sugg}`"), - ); - } - } - } -} - -declare_lint_pass!(OuterExpnDataPass => [OUTER_EXPN_EXPN_DATA]); - -impl<'tcx> LateLintPass<'tcx> for OuterExpnDataPass { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if is_lint_allowed(cx, OUTER_EXPN_EXPN_DATA, expr.hir_id) { - return; - } - - let (method_names, arg_lists, spans) = method_calls(expr, 2); - let method_names: Vec<&str> = method_names.iter().map(Symbol::as_str).collect(); - if_chain! { - if let ["expn_data", "outer_expn"] = method_names.as_slice(); - let (self_arg, args)= arg_lists[1]; - if args.is_empty(); - let self_ty = cx.typeck_results().expr_ty(self_arg).peel_refs(); - if match_type(cx, self_ty, &paths::SYNTAX_CONTEXT); - then { - span_lint_and_sugg( - cx, - OUTER_EXPN_EXPN_DATA, - spans[1].with_hi(expr.span.hi()), - "usage of `outer_expn().expn_data()`", - "try", - "outer_expn_data()".to_string(), - Applicability::MachineApplicable, - ); - } - } - } -} - -declare_lint_pass!(ProduceIce => [PRODUCE_ICE]); - -impl EarlyLintPass for ProduceIce { - fn check_fn(&mut self, _: &EarlyContext<'_>, fn_kind: FnKind<'_>, _: Span, _: NodeId) { - assert!(!is_trigger_fn(fn_kind), "Would you like some help with that?"); - } -} - -fn is_trigger_fn(fn_kind: FnKind<'_>) -> bool { - match fn_kind { - FnKind::Fn(_, ident, ..) => ident.name.as_str() == "it_looks_like_you_are_trying_to_kill_clippy", - FnKind::Closure(..) => false, - } -} - -declare_lint_pass!(CollapsibleCalls => [COLLAPSIBLE_SPAN_LINT_CALLS]); - -impl<'tcx> LateLintPass<'tcx> for CollapsibleCalls { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if is_lint_allowed(cx, COLLAPSIBLE_SPAN_LINT_CALLS, expr.hir_id) { - return; - } - - if_chain! { - if let ExprKind::Call(func, and_then_args) = expr.kind; - if is_expr_path_def_path(cx, func, &["clippy_utils", "diagnostics", "span_lint_and_then"]); - if and_then_args.len() == 5; - if let ExprKind::Closure(&Closure { body, .. }) = &and_then_args[4].kind; - let body = cx.tcx.hir().body(body); - let only_expr = peel_blocks_with_stmt(body.value); - if let ExprKind::MethodCall(ps, recv, span_call_args, _) = &only_expr.kind; - if let ExprKind::Path(..) = recv.kind; - then { - let and_then_snippets = get_and_then_snippets(cx, and_then_args); - let mut sle = SpanlessEq::new(cx).deny_side_effects(); - match ps.ident.as_str() { - "span_suggestion" if sle.eq_expr(&and_then_args[2], &span_call_args[0]) => { - suggest_suggestion(cx, expr, &and_then_snippets, &span_suggestion_snippets(cx, span_call_args)); - }, - "span_help" if sle.eq_expr(&and_then_args[2], &span_call_args[0]) => { - let help_snippet = snippet(cx, span_call_args[1].span, r#""...""#); - suggest_help(cx, expr, &and_then_snippets, help_snippet.borrow(), true); - }, - "span_note" if sle.eq_expr(&and_then_args[2], &span_call_args[0]) => { - let note_snippet = snippet(cx, span_call_args[1].span, r#""...""#); - suggest_note(cx, expr, &and_then_snippets, note_snippet.borrow(), true); - }, - "help" => { - let help_snippet = snippet(cx, span_call_args[0].span, r#""...""#); - suggest_help(cx, expr, &and_then_snippets, help_snippet.borrow(), false); - } - "note" => { - let note_snippet = snippet(cx, span_call_args[0].span, r#""...""#); - suggest_note(cx, expr, &and_then_snippets, note_snippet.borrow(), false); - } - _ => (), - } - } - } - } -} - -struct AndThenSnippets<'a> { - cx: Cow<'a, str>, - lint: Cow<'a, str>, - span: Cow<'a, str>, - msg: Cow<'a, str>, -} - -fn get_and_then_snippets<'a, 'hir>(cx: &LateContext<'_>, and_then_snippets: &'hir [Expr<'hir>]) -> AndThenSnippets<'a> { - let cx_snippet = snippet(cx, and_then_snippets[0].span, "cx"); - let lint_snippet = snippet(cx, and_then_snippets[1].span, ".."); - let span_snippet = snippet(cx, and_then_snippets[2].span, "span"); - let msg_snippet = snippet(cx, and_then_snippets[3].span, r#""...""#); - - AndThenSnippets { - cx: cx_snippet, - lint: lint_snippet, - span: span_snippet, - msg: msg_snippet, - } -} - -struct SpanSuggestionSnippets<'a> { - help: Cow<'a, str>, - sugg: Cow<'a, str>, - applicability: Cow<'a, str>, -} - -fn span_suggestion_snippets<'a, 'hir>( - cx: &LateContext<'_>, - span_call_args: &'hir [Expr<'hir>], -) -> SpanSuggestionSnippets<'a> { - let help_snippet = snippet(cx, span_call_args[1].span, r#""...""#); - let sugg_snippet = snippet(cx, span_call_args[2].span, ".."); - let applicability_snippet = snippet(cx, span_call_args[3].span, "Applicability::MachineApplicable"); - - SpanSuggestionSnippets { - help: help_snippet, - sugg: sugg_snippet, - applicability: applicability_snippet, - } -} - -fn suggest_suggestion( - cx: &LateContext<'_>, - expr: &Expr<'_>, - and_then_snippets: &AndThenSnippets<'_>, - span_suggestion_snippets: &SpanSuggestionSnippets<'_>, -) { - span_lint_and_sugg( - cx, - COLLAPSIBLE_SPAN_LINT_CALLS, - expr.span, - "this call is collapsible", - "collapse into", - format!( - "span_lint_and_sugg({}, {}, {}, {}, {}, {}, {})", - and_then_snippets.cx, - and_then_snippets.lint, - and_then_snippets.span, - and_then_snippets.msg, - span_suggestion_snippets.help, - span_suggestion_snippets.sugg, - span_suggestion_snippets.applicability - ), - Applicability::MachineApplicable, - ); -} - -fn suggest_help( - cx: &LateContext<'_>, - expr: &Expr<'_>, - and_then_snippets: &AndThenSnippets<'_>, - help: &str, - with_span: bool, -) { - let option_span = if with_span { - format!("Some({})", and_then_snippets.span) - } else { - "None".to_string() - }; - - span_lint_and_sugg( - cx, - COLLAPSIBLE_SPAN_LINT_CALLS, - expr.span, - "this call is collapsible", - "collapse into", - format!( - "span_lint_and_help({}, {}, {}, {}, {}, {help})", - and_then_snippets.cx, and_then_snippets.lint, and_then_snippets.span, and_then_snippets.msg, &option_span, - ), - Applicability::MachineApplicable, - ); -} - -fn suggest_note( - cx: &LateContext<'_>, - expr: &Expr<'_>, - and_then_snippets: &AndThenSnippets<'_>, - note: &str, - with_span: bool, -) { - let note_span = if with_span { - format!("Some({})", and_then_snippets.span) - } else { - "None".to_string() - }; - - span_lint_and_sugg( - cx, - COLLAPSIBLE_SPAN_LINT_CALLS, - expr.span, - "this call is collapsible", - "collapse into", - format!( - "span_lint_and_note({}, {}, {}, {}, {note_span}, {note})", - and_then_snippets.cx, and_then_snippets.lint, and_then_snippets.span, and_then_snippets.msg, - ), - Applicability::MachineApplicable, - ); -} - -declare_lint_pass!(UnnecessaryDefPath => [UNNECESSARY_DEF_PATH]); - -#[allow(clippy::too_many_lines)] -impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - enum Item { - LangItem(Symbol), - DiagnosticItem(Symbol), - } - static PATHS: &[&[&str]] = &[ - &["clippy_utils", "match_def_path"], - &["clippy_utils", "match_trait_method"], - &["clippy_utils", "ty", "match_type"], - &["clippy_utils", "is_expr_path_def_path"], - ]; - - if is_lint_allowed(cx, UNNECESSARY_DEF_PATH, expr.hir_id) { - return; - } - - if_chain! { - if let ExprKind::Call(func, [cx_arg, def_arg, args@..]) = expr.kind; - if let ExprKind::Path(path) = &func.kind; - if let Some(id) = cx.qpath_res(path, func.hir_id).opt_def_id(); - if let Some(which_path) = match_any_def_paths(cx, id, PATHS); - let item_arg = if which_path == 4 { &args[1] } else { &args[0] }; - // Extract the path to the matched type - if let Some(segments) = path_to_matched_type(cx, item_arg); - let segments: Vec<&str> = segments.iter().map(|sym| &**sym).collect(); - if let Some(def_id) = def_path_res(cx, &segments[..], None).opt_def_id(); - then { - // def_path_res will match field names before anything else, but for this we want to match - // inherent functions first. - let def_id = if cx.tcx.def_kind(def_id) == DefKind::Field { - let method_name = *segments.last().unwrap(); - cx.tcx.def_key(def_id).parent - .and_then(|parent_idx| - cx.tcx.inherent_impls(DefId { index: parent_idx, krate: def_id.krate }).iter() - .find_map(|impl_id| cx.tcx.associated_items(*impl_id) - .find_by_name_and_kind( - cx.tcx, - Ident::from_str(method_name), - AssocKind::Fn, - *impl_id, - ) - ) - ) - .map_or(def_id, |item| item.def_id) - } else { - def_id - }; - - // Check if the target item is a diagnostic item or LangItem. - let (msg, item) = if let Some(item_name) - = cx.tcx.diagnostic_items(def_id.krate).id_to_name.get(&def_id) - { - ( - "use of a def path to a diagnostic item", - Item::DiagnosticItem(*item_name), - ) - } else if let Some(lang_item) = cx.tcx.lang_items().items().iter().position(|id| *id == Some(def_id)) { - let lang_items = def_path_res(cx, &["rustc_hir", "lang_items", "LangItem"], Some(Namespace::TypeNS)).def_id(); - let item_name = cx.tcx.adt_def(lang_items).variants().iter().nth(lang_item).unwrap().name; - ( - "use of a def path to a `LangItem`", - Item::LangItem(item_name), - ) - } else { - return; - }; - - let has_ctor = match cx.tcx.def_kind(def_id) { - DefKind::Struct => { - let variant = cx.tcx.adt_def(def_id).non_enum_variant(); - variant.ctor_def_id.is_some() && variant.fields.iter().all(|f| f.vis.is_public()) - } - DefKind::Variant => { - let variant = cx.tcx.adt_def(cx.tcx.parent(def_id)).variant_with_id(def_id); - variant.ctor_def_id.is_some() && variant.fields.iter().all(|f| f.vis.is_public()) - } - _ => false, - }; - - let mut app = Applicability::MachineApplicable; - let cx_snip = snippet_with_applicability(cx, cx_arg.span, "..", &mut app); - let def_snip = snippet_with_applicability(cx, def_arg.span, "..", &mut app); - let (sugg, with_note) = match (which_path, item) { - // match_def_path - (0, Item::DiagnosticItem(item)) => - (format!("{cx_snip}.tcx.is_diagnostic_item(sym::{item}, {def_snip})"), has_ctor), - (0, Item::LangItem(item)) => ( - format!("{cx_snip}.tcx.lang_items().require(LangItem::{item}).ok() == Some({def_snip})"), - has_ctor - ), - // match_trait_method - (1, Item::DiagnosticItem(item)) => - (format!("is_trait_method({cx_snip}, {def_snip}, sym::{item})"), false), - // match_type - (2, Item::DiagnosticItem(item)) => - (format!("is_type_diagnostic_item({cx_snip}, {def_snip}, sym::{item})"), false), - (2, Item::LangItem(item)) => - (format!("is_type_lang_item({cx_snip}, {def_snip}, LangItem::{item})"), false), - // is_expr_path_def_path - (3, Item::DiagnosticItem(item)) if has_ctor => ( - format!( - "is_res_diag_ctor({cx_snip}, path_res({cx_snip}, {def_snip}), sym::{item})", - ), - false, - ), - (3, Item::LangItem(item)) if has_ctor => ( - format!( - "is_res_lang_ctor({cx_snip}, path_res({cx_snip}, {def_snip}), LangItem::{item})", - ), - false, - ), - (3, Item::DiagnosticItem(item)) => - (format!("is_path_diagnostic_item({cx_snip}, {def_snip}, sym::{item})"), false), - (3, Item::LangItem(item)) => ( - format!( - "path_res({cx_snip}, {def_snip}).opt_def_id()\ - .map_or(false, |id| {cx_snip}.tcx.lang_items().require(LangItem::{item}).ok() == Some(id))", - ), - false, - ), - _ => return, - }; - - span_lint_and_then( - cx, - UNNECESSARY_DEF_PATH, - expr.span, - msg, - |diag| { - diag.span_suggestion(expr.span, "try", sugg, app); - if with_note { - diag.help( - "if this `DefId` came from a constructor expression or pattern then the \ - parent `DefId` should be used instead" - ); - } - }, - ); - } - } - } -} - -fn path_to_matched_type(cx: &LateContext<'_>, expr: &hir::Expr<'_>) -> Option<Vec<String>> { - match peel_hir_expr_refs(expr).0.kind { - ExprKind::Path(ref qpath) => match cx.qpath_res(qpath, expr.hir_id) { - Res::Local(hir_id) => { - let parent_id = cx.tcx.hir().get_parent_node(hir_id); - if let Some(Node::Local(Local { init: Some(init), .. })) = cx.tcx.hir().find(parent_id) { - path_to_matched_type(cx, init) - } else { - None - } - }, - 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), - ), - Res::Def(DefKind::Const, def_id) => match cx.tcx.const_eval_poly(def_id).ok()? { - ConstValue::ByRef { alloc, offset } if offset.bytes() == 0 => { - read_mir_alloc_def_path(cx, alloc.inner(), cx.tcx.type_of(def_id)) - }, - _ => None, - }, - _ => None, - }, - ExprKind::Array(exprs) => exprs - .iter() - .map(|expr| { - if let ExprKind::Lit(lit) = &expr.kind { - if let LitKind::Str(sym, _) = lit.node { - return Some((*sym.as_str()).to_owned()); - } - } - - None - }) - .collect(), - _ => None, - } -} - -fn read_mir_alloc_def_path<'tcx>(cx: &LateContext<'tcx>, alloc: &'tcx Allocation, ty: Ty<'_>) -> Option<Vec<String>> { - let (alloc, ty) = if let ty::Ref(_, ty, Mutability::Not) = *ty.kind() { - let &alloc = alloc.provenance().values().next()?; - if let GlobalAlloc::Memory(alloc) = cx.tcx.global_alloc(alloc) { - (alloc.inner(), ty) - } else { - return None; - } - } else { - (alloc, ty) - }; - - if let ty::Array(ty, _) | ty::Slice(ty) = *ty.kind() - && let ty::Ref(_, ty, Mutability::Not) = *ty.kind() - && ty.is_str() - { - alloc - .provenance() - .values() - .map(|&alloc| { - if let GlobalAlloc::Memory(alloc) = cx.tcx.global_alloc(alloc) { - let alloc = alloc.inner(); - str::from_utf8(alloc.inspect_with_uninit_and_ptr_outside_interpreter(0..alloc.len())) - .ok().map(ToOwned::to_owned) - } else { - None - } - }) - .collect() - } else { - None - } -} - -// This is not a complete resolver for paths. It works on all the paths currently used in the paths -// module. That's all it does and all it needs to do. -pub fn check_path(cx: &LateContext<'_>, path: &[&str]) -> bool { - if def_path_res(cx, path, None) != Res::Err { - return true; - } - - // Some implementations can't be found by `path_to_res`, particularly inherent - // implementations of native types. Check lang items. - let path_syms: Vec<_> = path.iter().map(|p| Symbol::intern(p)).collect(); - let lang_items = cx.tcx.lang_items(); - // This list isn't complete, but good enough for our current list of paths. - let incoherent_impls = [ - SimplifiedTypeGen::FloatSimplifiedType(FloatTy::F32), - SimplifiedTypeGen::FloatSimplifiedType(FloatTy::F64), - SimplifiedTypeGen::SliceSimplifiedType, - SimplifiedTypeGen::StrSimplifiedType, - ] - .iter() - .flat_map(|&ty| cx.tcx.incoherent_impls(ty)); - for item_def_id in lang_items.items().iter().flatten().chain(incoherent_impls) { - let lang_item_path = cx.get_def_path(*item_def_id); - if path_syms.starts_with(&lang_item_path) { - if let [item] = &path_syms[lang_item_path.len()..] { - if matches!( - cx.tcx.def_kind(*item_def_id), - DefKind::Mod | DefKind::Enum | DefKind::Trait - ) { - for child in cx.tcx.module_children(*item_def_id) { - if child.ident.name == *item { - return true; - } - } - } else { - for child in cx.tcx.associated_item_def_ids(*item_def_id) { - if cx.tcx.item_name(*child) == *item { - return true; - } - } - } - } - } - } - - false -} - -declare_lint_pass!(InvalidPaths => [INVALID_PATHS]); - -impl<'tcx> LateLintPass<'tcx> for InvalidPaths { - fn check_item(&mut self, cx: &LateContext<'tcx>, item: &'tcx Item<'_>) { - let local_def_id = &cx.tcx.parent_module(item.hir_id()); - let mod_name = &cx.tcx.item_name(local_def_id.to_def_id()); - if_chain! { - if mod_name.as_str() == "paths"; - if let hir::ItemKind::Const(ty, body_id) = item.kind; - let ty = hir_ty_to_ty(cx.tcx, ty); - if let ty::Array(el_ty, _) = &ty.kind(); - if let ty::Ref(_, el_ty, _) = &el_ty.kind(); - if el_ty.is_str(); - let body = cx.tcx.hir().body(body_id); - let typeck_results = cx.tcx.typeck_body(body_id); - if let Some(Constant::Vec(path)) = constant_simple(cx, typeck_results, body.value); - let path: Vec<&str> = path.iter().map(|x| { - if let Constant::Str(s) = x { - s.as_str() - } else { - // We checked the type of the constant above - unreachable!() - } - }).collect(); - if !check_path(cx, &path[..]); - then { - span_lint(cx, INVALID_PATHS, item.span, "invalid path"); - } - } - } -} - -#[derive(Default)] -pub struct InterningDefinedSymbol { - // Maps the symbol value to the constant DefId. - symbol_map: FxHashMap<u32, DefId>, -} - -impl_lint_pass!(InterningDefinedSymbol => [INTERNING_DEFINED_SYMBOL, UNNECESSARY_SYMBOL_STR]); - -impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { - fn check_crate(&mut self, cx: &LateContext<'_>) { - if !self.symbol_map.is_empty() { - return; - } - - for &module in &[&paths::KW_MODULE, &paths::SYM_MODULE] { - if let Some(def_id) = def_path_res(cx, module, None).opt_def_id() { - for item in cx.tcx.module_children(def_id).iter() { - if_chain! { - if let Res::Def(DefKind::Const, item_def_id) = item.res; - let ty = cx.tcx.type_of(item_def_id); - if match_type(cx, ty, &paths::SYMBOL); - if let Ok(ConstValue::Scalar(value)) = cx.tcx.const_eval_poly(item_def_id); - if let Ok(value) = value.to_u32(); - then { - self.symbol_map.insert(value, item_def_id); - } - } - } - } - } - } - - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { - if_chain! { - if let ExprKind::Call(func, [arg]) = &expr.kind; - if let ty::FnDef(def_id, _) = cx.typeck_results().expr_ty(func).kind(); - if match_def_path(cx, *def_id, &paths::SYMBOL_INTERN); - if let Some(Constant::Str(arg)) = constant_simple(cx, cx.typeck_results(), arg); - let value = Symbol::intern(&arg).as_u32(); - if let Some(&def_id) = self.symbol_map.get(&value); - then { - span_lint_and_sugg( - cx, - INTERNING_DEFINED_SYMBOL, - is_expn_of(expr.span, "sym").unwrap_or(expr.span), - "interning a defined symbol", - "try", - cx.tcx.def_path_str(def_id), - Applicability::MachineApplicable, - ); - } - } - if let ExprKind::Binary(op, left, right) = expr.kind { - if matches!(op.node, BinOpKind::Eq | BinOpKind::Ne) { - let data = [ - (left, self.symbol_str_expr(left, cx)), - (right, self.symbol_str_expr(right, cx)), - ]; - match data { - // both operands are a symbol string - [(_, Some(left)), (_, Some(right))] => { - span_lint_and_sugg( - cx, - UNNECESSARY_SYMBOL_STR, - expr.span, - "unnecessary `Symbol` to string conversion", - "try", - format!( - "{} {} {}", - left.as_symbol_snippet(cx), - op.node.as_str(), - right.as_symbol_snippet(cx), - ), - Applicability::MachineApplicable, - ); - }, - // one of the operands is a symbol string - [(expr, Some(symbol)), _] | [_, (expr, Some(symbol))] => { - // creating an owned string for comparison - if matches!(symbol, SymbolStrExpr::Expr { is_to_owned: true, .. }) { - span_lint_and_sugg( - cx, - UNNECESSARY_SYMBOL_STR, - expr.span, - "unnecessary string allocation", - "try", - format!("{}.as_str()", symbol.as_symbol_snippet(cx)), - Applicability::MachineApplicable, - ); - } - }, - // nothing found - [(_, None), (_, None)] => {}, - } - } - } - } -} - -impl InterningDefinedSymbol { - fn symbol_str_expr<'tcx>(&self, expr: &'tcx Expr<'tcx>, cx: &LateContext<'tcx>) -> Option<SymbolStrExpr<'tcx>> { - static IDENT_STR_PATHS: &[&[&str]] = &[&paths::IDENT_AS_STR, &paths::TO_STRING_METHOD]; - static SYMBOL_STR_PATHS: &[&[&str]] = &[ - &paths::SYMBOL_AS_STR, - &paths::SYMBOL_TO_IDENT_STRING, - &paths::TO_STRING_METHOD, - ]; - let call = if_chain! { - if let ExprKind::AddrOf(_, _, e) = expr.kind; - if let ExprKind::Unary(UnOp::Deref, e) = e.kind; - then { e } else { expr } - }; - if_chain! { - // is a method call - if let ExprKind::MethodCall(_, item, [], _) = call.kind; - if let Some(did) = cx.typeck_results().type_dependent_def_id(call.hir_id); - let ty = cx.typeck_results().expr_ty(item); - // ...on either an Ident or a Symbol - if let Some(is_ident) = if match_type(cx, ty, &paths::SYMBOL) { - Some(false) - } else if match_type(cx, ty, &paths::IDENT) { - Some(true) - } else { - None - }; - // ...which converts it to a string - let paths = if is_ident { IDENT_STR_PATHS } else { SYMBOL_STR_PATHS }; - if let Some(path) = paths.iter().find(|path| match_def_path(cx, did, path)); - then { - let is_to_owned = path.last().unwrap().ends_with("string"); - return Some(SymbolStrExpr::Expr { - item, - is_ident, - is_to_owned, - }); - } - } - // is a string constant - if let Some(Constant::Str(s)) = constant_simple(cx, cx.typeck_results(), expr) { - let value = Symbol::intern(&s).as_u32(); - // ...which matches a symbol constant - if let Some(&def_id) = self.symbol_map.get(&value) { - return Some(SymbolStrExpr::Const(def_id)); - } - } - None - } -} - -enum SymbolStrExpr<'tcx> { - /// a string constant with a corresponding symbol constant - Const(DefId), - /// a "symbol to string" expression like `symbol.as_str()` - Expr { - /// part that evaluates to `Symbol` or `Ident` - item: &'tcx Expr<'tcx>, - is_ident: bool, - /// whether an owned `String` is created like `to_ident_string()` - is_to_owned: bool, - }, -} - -impl<'tcx> SymbolStrExpr<'tcx> { - /// Returns a snippet that evaluates to a `Symbol` and is const if possible - fn as_symbol_snippet(&self, cx: &LateContext<'_>) -> Cow<'tcx, str> { - match *self { - Self::Const(def_id) => cx.tcx.def_path_str(def_id).into(), - Self::Expr { item, is_ident, .. } => { - let mut snip = snippet(cx, item.span.source_callsite(), ".."); - if is_ident { - // get `Ident.name` - snip.to_mut().push_str(".name"); - } - snip - }, - } - } -} - -declare_lint_pass!(IfChainStyle => [IF_CHAIN_STYLE]); - -impl<'tcx> LateLintPass<'tcx> for IfChainStyle { - fn check_block(&mut self, cx: &LateContext<'tcx>, block: &'tcx hir::Block<'_>) { - let (local, after, if_chain_span) = if_chain! { - if let [Stmt { kind: StmtKind::Local(local), .. }, after @ ..] = block.stmts; - if let Some(if_chain_span) = is_expn_of(block.span, "if_chain"); - then { (local, after, if_chain_span) } else { return } - }; - if is_first_if_chain_expr(cx, block.hir_id, if_chain_span) { - span_lint( - cx, - IF_CHAIN_STYLE, - if_chain_local_span(cx, local, if_chain_span), - "`let` expression should be above the `if_chain!`", - ); - } else if local.span.ctxt() == block.span.ctxt() && is_if_chain_then(after, block.expr, if_chain_span) { - span_lint( - cx, - IF_CHAIN_STYLE, - if_chain_local_span(cx, local, if_chain_span), - "`let` expression should be inside `then { .. }`", - ); - } - } - - fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - let (cond, then, els) = if let Some(higher::IfOrIfLet { cond, r#else, then }) = higher::IfOrIfLet::hir(expr) { - (cond, then, r#else.is_some()) - } else { - return; - }; - let then_block = match then.kind { - ExprKind::Block(block, _) => block, - _ => return, - }; - let if_chain_span = is_expn_of(expr.span, "if_chain"); - if !els { - check_nested_if_chains(cx, expr, then_block, if_chain_span); - } - let if_chain_span = match if_chain_span { - None => return, - Some(span) => span, - }; - // check for `if a && b;` - if_chain! { - if let ExprKind::Binary(op, _, _) = cond.kind; - if op.node == BinOpKind::And; - if cx.sess().source_map().is_multiline(cond.span); - then { - span_lint(cx, IF_CHAIN_STYLE, cond.span, "`if a && b;` should be `if a; if b;`"); - } - } - if is_first_if_chain_expr(cx, expr.hir_id, if_chain_span) - && is_if_chain_then(then_block.stmts, then_block.expr, if_chain_span) - { - span_lint(cx, IF_CHAIN_STYLE, expr.span, "`if_chain!` only has one `if`"); - } - } -} - -fn check_nested_if_chains( - cx: &LateContext<'_>, - if_expr: &Expr<'_>, - then_block: &Block<'_>, - if_chain_span: Option<Span>, -) { - #[rustfmt::skip] - let (head, tail) = match *then_block { - Block { stmts, expr: Some(tail), .. } => (stmts, tail), - Block { - stmts: &[ - ref head @ .., - Stmt { kind: StmtKind::Expr(tail) | StmtKind::Semi(tail), .. } - ], - .. - } => (head, tail), - _ => return, - }; - if_chain! { - if let Some(higher::IfOrIfLet { r#else: None, .. }) = higher::IfOrIfLet::hir(tail); - let sm = cx.sess().source_map(); - if head - .iter() - .all(|stmt| matches!(stmt.kind, StmtKind::Local(..)) && !sm.is_multiline(stmt.span)); - if if_chain_span.is_some() || !is_else_clause(cx.tcx, if_expr); - then {} else { return } - } - let (span, msg) = match (if_chain_span, is_expn_of(tail.span, "if_chain")) { - (None, Some(_)) => (if_expr.span, "this `if` can be part of the inner `if_chain!`"), - (Some(_), None) => (tail.span, "this `if` can be part of the outer `if_chain!`"), - (Some(a), Some(b)) if a != b => (b, "this `if_chain!` can be merged with the outer `if_chain!`"), - _ => return, - }; - span_lint_and_then(cx, IF_CHAIN_STYLE, span, msg, |diag| { - let (span, msg) = match head { - [] => return, - [stmt] => (stmt.span, "this `let` statement can also be in the `if_chain!`"), - [a, .., b] => ( - a.span.to(b.span), - "these `let` statements can also be in the `if_chain!`", - ), - }; - diag.span_help(span, msg); - }); -} - -fn is_first_if_chain_expr(cx: &LateContext<'_>, hir_id: HirId, if_chain_span: Span) -> bool { - cx.tcx - .hir() - .parent_iter(hir_id) - .find(|(_, node)| { - #[rustfmt::skip] - !matches!(node, Node::Expr(Expr { kind: ExprKind::Block(..), .. }) | Node::Stmt(_)) - }) - .map_or(false, |(id, _)| { - is_expn_of(cx.tcx.hir().span(id), "if_chain") != Some(if_chain_span) - }) -} - -/// Checks a trailing slice of statements and expression of a `Block` to see if they are part -/// of the `then {..}` portion of an `if_chain!` -fn is_if_chain_then(stmts: &[Stmt<'_>], expr: Option<&Expr<'_>>, if_chain_span: Span) -> bool { - let span = if let [stmt, ..] = stmts { - stmt.span - } else if let Some(expr) = expr { - expr.span - } else { - // empty `then {}` - return true; - }; - is_expn_of(span, "if_chain").map_or(true, |span| span != if_chain_span) -} - -/// Creates a `Span` for `let x = ..;` in an `if_chain!` call. -fn if_chain_local_span(cx: &LateContext<'_>, local: &Local<'_>, if_chain_span: Span) -> Span { - let mut span = local.pat.span; - if let Some(init) = local.init { - span = span.to(init.span); - } - span.adjust(if_chain_span.ctxt().outer_expn()); - let sm = cx.sess().source_map(); - let span = sm.span_extend_to_prev_str(span, "let", false, true).unwrap_or(span); - let span = sm.span_extend_to_next_char(span, ';', false); - Span::new( - span.lo() - BytePos(3), - span.hi() + BytePos(1), - span.ctxt(), - span.parent(), - ) -} - -declare_lint_pass!(MsrvAttrImpl => [MISSING_MSRV_ATTR_IMPL]); - -impl LateLintPass<'_> for MsrvAttrImpl { - fn check_item(&mut self, cx: &LateContext<'_>, item: &hir::Item<'_>) { - if_chain! { - if let hir::ItemKind::Impl(hir::Impl { - of_trait: Some(lint_pass_trait_ref), - self_ty, - items, - .. - }) = &item.kind; - if let Some(lint_pass_trait_def_id) = lint_pass_trait_ref.trait_def_id(); - let is_late_pass = match_def_path(cx, lint_pass_trait_def_id, &paths::LATE_LINT_PASS); - if is_late_pass || match_def_path(cx, lint_pass_trait_def_id, &paths::EARLY_LINT_PASS); - let self_ty = hir_ty_to_ty(cx.tcx, self_ty); - if let ty::Adt(self_ty_def, _) = self_ty.kind(); - if self_ty_def.is_struct(); - if self_ty_def.all_fields().any(|f| { - cx.tcx - .type_of(f.did) - .walk() - .filter(|t| matches!(t.unpack(), GenericArgKind::Type(_))) - .any(|t| match_type(cx, t.expect_ty(), &paths::RUSTC_VERSION)) - }); - if !items.iter().any(|item| item.ident.name == sym!(enter_lint_attrs)); - then { - let context = if is_late_pass { "LateContext" } else { "EarlyContext" }; - let lint_pass = if is_late_pass { "LateLintPass" } else { "EarlyLintPass" }; - let span = cx.sess().source_map().span_through_char(item.span, '{'); - span_lint_and_sugg( - cx, - MISSING_MSRV_ATTR_IMPL, - span, - &format!("`extract_msrv_attr!` macro missing from `{lint_pass}` implementation"), - &format!("add `extract_msrv_attr!({context})` to the `{lint_pass}` implementation"), - format!("{}\n extract_msrv_attr!({context});", snippet(cx, span, "..")), - Applicability::MachineApplicable, - ); - } - } - } -} +pub mod msrv_attr_impl; +pub mod outer_expn_data_pass; +pub mod produce_ice; +pub mod unnecessary_def_path; |