diff options
Diffstat (limited to 'clippy_lints/src/utils/internal_lints.rs')
| -rw-r--r-- | clippy_lints/src/utils/internal_lints.rs | 307 |
1 files changed, 218 insertions, 89 deletions
diff --git a/clippy_lints/src/utils/internal_lints.rs b/clippy_lints/src/utils/internal_lints.rs index 78c036186f5..85bcbc7ad23 100644 --- a/clippy_lints/src/utils/internal_lints.rs +++ b/clippy_lints/src/utils/internal_lints.rs @@ -2,11 +2,11 @@ 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; +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_def_path, - method_calls, paths, peel_blocks_with_stmt, SpanlessEq, + 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; @@ -15,26 +15,29 @@ 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, Res}; +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, Ty, + 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::ConstValue; -use rustc_middle::ty::{self, fast_reject::SimplifiedTypeGen, subst::GenericArgKind, FloatTy}; +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::Symbol; +use rustc_span::symbol::{Ident, Symbol}; use rustc_span::{sym, BytePos, Span}; -use rustc_hir_analysis::hir_ty_to_ty; use std::borrow::{Borrow, Cow}; +use std::str; #[cfg(feature = "internal")] pub mod metadata_collector; @@ -226,11 +229,11 @@ declare_clippy_lint! { declare_clippy_lint! { /// ### What it does - /// Checks for calls to `utils::match_type()` on a type diagnostic item - /// and suggests to use `utils::is_type_diagnostic_item()` instead. + /// Checks for usages of def paths when a diagnostic item or a `LangItem` could be used. /// /// ### Why is this bad? - /// `utils::is_type_diagnostic_item()` does not require hardcoded paths. + /// 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 @@ -241,9 +244,9 @@ declare_clippy_lint! { /// ```rust,ignore /// utils::is_type_diagnostic_item(cx, ty, sym::Vec) /// ``` - pub MATCH_TYPE_ON_DIAGNOSTIC_ITEM, + pub UNNECESSARY_DEF_PATH, internal, - "using `utils::match_type()` instead of `utils::is_type_diagnostic_item()`" + "using a def path when a diagnostic item or a `LangItem` is available" } declare_clippy_lint! { @@ -530,14 +533,14 @@ impl<'tcx> LateLintPass<'tcx> for LintWithoutLintPass { cx, LINT_WITHOUT_LINT_PASS, lint_span, - &format!("the lint `{}` is not added to any `LintPass`", lint_name), + &format!("the lint `{lint_name}` is not added to any `LintPass`"), ); } } } } -fn is_lint_ref_type<'tcx>(cx: &LateContext<'tcx>, ty: &Ty<'_>) -> bool { +fn is_lint_ref_type<'tcx>(cx: &LateContext<'tcx>, ty: &hir::Ty<'_>) -> bool { if let TyKind::Rptr( _, MutTy { @@ -666,7 +669,7 @@ impl<'tcx> LateLintPass<'tcx> for CompilerLintFunctions { path.ident.span, "usage of a compiler lint function", None, - &format!("please use the Clippy variant of this function: `{}`", sugg), + &format!("please use the Clippy variant of this function: `{sugg}`"), ); } } @@ -854,13 +857,8 @@ fn suggest_help( "this call is collapsible", "collapse into", format!( - "span_lint_and_help({}, {}, {}, {}, {}, {})", - and_then_snippets.cx, - and_then_snippets.lint, - and_then_snippets.span, - and_then_snippets.msg, - &option_span, - help + "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, ); @@ -886,107 +884,238 @@ fn suggest_note( "this call is collapsible", "collapse into", format!( - "span_lint_and_note({}, {}, {}, {}, {}, {})", - and_then_snippets.cx, - and_then_snippets.lint, - and_then_snippets.span, - and_then_snippets.msg, - note_span, - note + "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!(MatchTypeOnDiagItem => [MATCH_TYPE_ON_DIAGNOSTIC_ITEM]); +declare_lint_pass!(UnnecessaryDefPath => [UNNECESSARY_DEF_PATH]); -impl<'tcx> LateLintPass<'tcx> for MatchTypeOnDiagItem { +#[allow(clippy::too_many_lines)] +impl<'tcx> LateLintPass<'tcx> for UnnecessaryDefPath { fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { - if is_lint_allowed(cx, MATCH_TYPE_ON_DIAGNOSTIC_ITEM, expr.hir_id) { + 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! { - // Check if this is a call to utils::match_type() - if let ExprKind::Call(fn_path, [context, ty, ty_path]) = expr.kind; - if is_expr_path_def_path(cx, fn_path, &["clippy_utils", "ty", "match_type"]); + 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, ty_path); - let segments: Vec<&str> = segments.iter().map(Symbol::as_str).collect(); - if let Some(ty_did) = def_path_res(cx, &segments[..]).opt_def_id(); - // Check if the matched type is a diagnostic item - if let Some(item_name) = cx.tcx.get_diagnostic_name(ty_did); + 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 { - // TODO: check paths constants from external crates. - let cx_snippet = snippet(cx, context.span, "_"); - let ty_snippet = snippet(cx, ty.span, "_"); + // 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 + }; - span_lint_and_sugg( + // 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, - MATCH_TYPE_ON_DIAGNOSTIC_ITEM, + UNNECESSARY_DEF_PATH, expr.span, - "usage of `clippy_utils::ty::match_type()` on a type diagnostic item", - "try", - format!("clippy_utils::ty::is_type_diagnostic_item({}, {}, sym::{})", cx_snippet, ty_snippet, item_name), - Applicability::MaybeIncorrect, + 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<Symbol>> { - use rustc_hir::ItemKind; - - match &expr.kind { - ExprKind::AddrOf(.., expr) => return path_to_matched_type(cx, expr), - ExprKind::Path(qpath) => match cx.qpath_res(qpath, expr.hir_id) { +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)) = cx.tcx.hir().find(parent_id) { - if let Some(init) = local.init { - return path_to_matched_type(cx, init); - } + 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::Const | DefKind::Static(..), def_id) => { - if let Some(Node::Item(item)) = cx.tcx.hir().get_if_local(def_id) { - if let ItemKind::Const(.., body_id) | ItemKind::Static(.., body_id) = item.kind { - let body = cx.tcx.hir().body(body_id); - return path_to_matched_type(cx, body.value); - } - } + 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) => { - let segments: Vec<Symbol> = exprs - .iter() - .filter_map(|expr| { - if let ExprKind::Lit(lit) = &expr.kind { - if let LitKind::Str(sym, _) = lit.node { - return Some(sym); - } + 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(); - - if segments.len() == exprs.len() { - return Some(segments); - } - }, - _ => {}, + 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) + }; - None + 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) != Res::Err { + if def_path_res(cx, path, None) != Res::Err { return true; } @@ -1077,7 +1206,7 @@ impl<'tcx> LateLintPass<'tcx> for InterningDefinedSymbol { } for &module in &[&paths::KW_MODULE, &paths::SYM_MODULE] { - if let Some(def_id) = def_path_res(cx, module).opt_def_id() { + 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; |