diff options
Diffstat (limited to 'clippy_lints/src/methods/mod.rs')
| -rw-r--r-- | clippy_lints/src/methods/mod.rs | 283 |
1 files changed, 158 insertions, 125 deletions
diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 8a04fd0060d..9a95354db7a 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -62,17 +62,18 @@ mod zst_offset; use bind_instead_of_map::BindInsteadOfMap; use clippy_utils::diagnostics::{span_lint, span_lint_and_help}; use clippy_utils::ty::{contains_adt_constructor, contains_ty, implements_trait, is_copy, is_type_diagnostic_item}; -use clippy_utils::{contains_return, get_trait_def_id, in_macro, iter_input_pats, method_calls, paths, return_ty}; +use clippy_utils::{contains_return, get_trait_def_id, in_macro, iter_input_pats, paths, return_ty}; use if_chain::if_chain; use rustc_hir as hir; use rustc_hir::def::Res; -use rustc_hir::{PrimTy, QPath, TraitItem, TraitItemKind}; +use rustc_hir::{Expr, ExprKind, PrimTy, QPath, TraitItem, TraitItemKind}; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::lint::in_external_macro; use rustc_middle::ty::{self, TraitRef, Ty, TyS}; use rustc_semver::RustcVersion; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::symbol::{sym, SymbolStr}; +use rustc_span::symbol::SymbolStr; +use rustc_span::{sym, Span}; use rustc_typeck::hir_ty_to_ty; declare_clippy_lint! { @@ -1704,134 +1705,32 @@ impl_lint_pass!(Methods => [ IMPLICIT_CLONE ]); +/// Extracts a method call name, args, and `Span` of the method name. +fn method_call<'tcx>(recv: &'tcx hir::Expr<'tcx>) -> Option<(SymbolStr, &'tcx [hir::Expr<'tcx>], Span)> { + if let ExprKind::MethodCall(path, span, args, _) = recv.kind { + if !args.iter().any(|e| e.span.from_expansion()) { + return Some((path.ident.name.as_str(), args, span)); + } + } + None +} + +/// Same as `method_call` but the `SymbolStr` is dereferenced into a temporary `&str` +macro_rules! method_call { + ($expr:expr) => { + method_call($expr) + .as_ref() + .map(|&(ref name, args, span)| (&**name, args, span)) + }; +} + impl<'tcx> LateLintPass<'tcx> for Methods { - #[allow(clippy::too_many_lines)] fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx hir::Expr<'_>) { if in_macro(expr.span) { return; } - let (method_names, arg_lists, method_spans) = method_calls(expr, 2); - let method_names: Vec<SymbolStr> = method_names.iter().map(|s| s.as_str()).collect(); - let method_names: Vec<&str> = method_names.iter().map(|s| &**s).collect(); - - match method_names.as_slice() { - ["unwrap", "get"] => get_unwrap::check(cx, expr, arg_lists[1], false), - ["unwrap", "get_mut"] => get_unwrap::check(cx, expr, arg_lists[1], true), - ["unwrap", ..] => unwrap_used::check(cx, expr, arg_lists[0]), - ["expect", "ok"] => ok_expect::check(cx, expr, arg_lists[1]), - ["expect", ..] => expect_used::check(cx, expr, arg_lists[0]), - ["unwrap_or", "map"] => option_map_unwrap_or::check(cx, expr, arg_lists[1], arg_lists[0], method_spans[1]), - ["unwrap_or_else", "map"] => { - if !map_unwrap_or::check(cx, expr, arg_lists[1], arg_lists[0], self.msrv.as_ref()) { - unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"); - } - }, - ["map_or", ..] => option_map_or_none::check(cx, expr, arg_lists[0]), - ["and_then", ..] => { - let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, arg_lists[0]); - let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, arg_lists[0]); - if !biom_option_linted && !biom_result_linted { - unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "and"); - } - }, - ["or_else", ..] => { - if !bind_instead_of_map::ResultOrElseErrInfo::check(cx, expr, arg_lists[0]) { - unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "or"); - } - }, - ["next", "filter"] => filter_next::check(cx, expr, arg_lists[1]), - ["next", "skip_while"] => skip_while_next::check(cx, expr, arg_lists[1]), - ["next", "iter"] => iter_next_slice::check(cx, expr, arg_lists[1]), - ["map", "filter"] => filter_map::check(cx, expr, false, method_spans[0]), - ["map", "filter_map"] => filter_map_map::check(cx, expr), - ["next", "filter_map"] => filter_map_next::check(cx, expr, arg_lists[1], self.msrv.as_ref()), - ["map", "find"] => filter_map::check(cx, expr, true, method_spans[0]), - ["flat_map", "filter"] => filter_flat_map::check(cx, expr), - ["flat_map", "filter_map"] => filter_map_flat_map::check(cx, expr), - ["flat_map", ..] => flat_map_identity::check(cx, expr, arg_lists[0], method_spans[0]), - ["flatten", "map"] => map_flatten::check(cx, expr, arg_lists[1]), - [option_check_method, "find"] if "is_some" == *option_check_method || "is_none" == *option_check_method => { - search_is_some::check( - cx, - expr, - "find", - option_check_method, - arg_lists[1], - arg_lists[0], - method_spans[1], - ) - }, - [option_check_method, "position"] - if "is_some" == *option_check_method || "is_none" == *option_check_method => - { - search_is_some::check( - cx, - expr, - "position", - option_check_method, - arg_lists[1], - arg_lists[0], - method_spans[1], - ) - }, - [option_check_method, "rposition"] - if "is_some" == *option_check_method || "is_none" == *option_check_method => - { - search_is_some::check( - cx, - expr, - "rposition", - option_check_method, - arg_lists[1], - arg_lists[0], - method_spans[1], - ) - }, - ["extend", ..] => string_extend_chars::check(cx, expr, arg_lists[0]), - ["count", "into_iter"] => iter_count::check(cx, expr, &arg_lists[1], "into_iter"), - ["count", "iter"] => iter_count::check(cx, expr, &arg_lists[1], "iter"), - ["count", "iter_mut"] => iter_count::check(cx, expr, &arg_lists[1], "iter_mut"), - ["nth", "iter"] => iter_nth::check(cx, expr, &arg_lists, false), - ["nth", "iter_mut"] => iter_nth::check(cx, expr, &arg_lists, true), - ["nth", "bytes"] => bytes_nth::check(cx, expr, &arg_lists[1]), - ["nth", ..] => iter_nth_zero::check(cx, expr, arg_lists[0]), - ["step_by", ..] => iterator_step_by_zero::check(cx, expr, arg_lists[0]), - ["next", "skip"] => iter_skip_next::check(cx, expr, arg_lists[1]), - ["collect", "cloned"] => iter_cloned_collect::check(cx, expr, arg_lists[1]), - ["as_ref"] => useless_asref::check(cx, expr, "as_ref", arg_lists[0]), - ["as_mut"] => useless_asref::check(cx, expr, "as_mut", arg_lists[0]), - ["fold", ..] => unnecessary_fold::check(cx, expr, arg_lists[0], method_spans[0]), - ["filter_map", ..] => { - unnecessary_filter_map::check(cx, expr, arg_lists[0]); - filter_map_identity::check(cx, expr, arg_lists[0], method_spans[0]); - }, - ["count", "map"] => suspicious_map::check(cx, expr, arg_lists[1], arg_lists[0]), - ["assume_init"] => uninit_assumed_init::check(cx, &arg_lists[0][0], expr), - ["unwrap_or", arith @ ("checked_add" | "checked_sub" | "checked_mul")] => { - manual_saturating_arithmetic::check(cx, expr, &arg_lists, &arith["checked_".len()..]) - }, - ["add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub"] => { - zst_offset::check(cx, expr, arg_lists[0]) - }, - ["is_file", ..] => filetype_is_file::check(cx, expr, arg_lists[0]), - ["map", "as_ref"] => { - option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], false, self.msrv.as_ref()) - }, - ["map", "as_mut"] => { - option_as_ref_deref::check(cx, expr, arg_lists[1], arg_lists[0], true, self.msrv.as_ref()) - }, - ["unwrap_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "unwrap_or"), - ["get_or_insert_with", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "get_or_insert"), - ["ok_or_else", ..] => unnecessary_lazy_eval::check(cx, expr, arg_lists[0], "ok_or"), - ["collect", "map"] => map_collect_result_unit::check(cx, expr, arg_lists[1], arg_lists[0]), - ["for_each", "inspect"] => inspect_for_each::check(cx, expr, method_spans[1]), - ["to_owned", ..] => implicit_clone::check(cx, expr, sym::ToOwned), - ["to_os_string", ..] => implicit_clone::check(cx, expr, sym::OsStr), - ["to_path_buf", ..] => implicit_clone::check(cx, expr, sym::Path), - ["to_vec", ..] => implicit_clone::check(cx, expr, sym::slice), - _ => {}, - } + check_methods(cx, expr, self.msrv.as_ref()); match expr.kind { hir::ExprKind::Call(ref func, ref args) => { @@ -2020,6 +1919,140 @@ impl<'tcx> LateLintPass<'tcx> for Methods { extract_msrv_attr!(LateContext); } + +#[allow(clippy::too_many_lines)] +fn check_methods<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, msrv: Option<&RustcVersion>) { + if let Some((name, [recv, args @ ..], span)) = method_call!(expr) { + match (name, args) { + ("add" | "offset" | "sub" | "wrapping_offset" | "wrapping_add" | "wrapping_sub", [recv, _]) => { + zst_offset::check(cx, expr, recv) + }, + ("and_then", [arg]) => { + let biom_option_linted = bind_instead_of_map::OptionAndThenSome::check(cx, expr, recv, arg); + let biom_result_linted = bind_instead_of_map::ResultAndThenOk::check(cx, expr, recv, arg); + if !biom_option_linted && !biom_result_linted { + unnecessary_lazy_eval::check(cx, expr, recv, arg, "and"); + } + }, + ("as_mut", []) => useless_asref::check(cx, expr, "as_mut", recv), + ("as_ref", []) => useless_asref::check(cx, expr, "as_ref", recv), + ("assume_init", []) => uninit_assumed_init::check(cx, expr, recv), + ("collect", []) => match method_call!(recv) { + Some(("cloned", [recv2], _)) => iter_cloned_collect::check(cx, expr, recv2), + Some(("map", [m_recv, m_arg], _)) => { + map_collect_result_unit::check(cx, expr, m_recv, m_arg, recv); + }, + _ => {}, + }, + ("count", []) => match method_call!(recv) { + Some((name @ ("into_iter" | "iter" | "iter_mut"), [recv2], _)) => { + iter_count::check(cx, expr, recv2, name); + }, + Some(("map", [_, arg], _)) => suspicious_map::check(cx, expr, recv, arg), + _ => {}, + }, + ("expect", [_]) => match method_call!(recv) { + Some(("ok", [recv], _)) => ok_expect::check(cx, expr, recv), + _ => expect_used::check(cx, expr, recv), + }, + ("extend", [arg]) => string_extend_chars::check(cx, expr, recv, arg), + ("filter_map", [arg]) => { + unnecessary_filter_map::check(cx, expr, arg); + filter_map_identity::check(cx, expr, arg, span); + }, + ("flat_map", [flm_arg]) => match method_call!(recv) { + Some(("filter", [_, _], _)) => filter_flat_map::check(cx, expr), + Some(("filter_map", [_, _], _)) => filter_map_flat_map::check(cx, expr), + _ => flat_map_identity::check(cx, expr, flm_arg, span), + }, + ("flatten", []) => { + if let Some(("map", [recv, map_arg], _)) = method_call!(recv) { + map_flatten::check(cx, expr, recv, map_arg); + } + }, + ("fold", [init, acc]) => unnecessary_fold::check(cx, expr, init, acc, span), + ("for_each", [_]) => { + if let Some(("inspect", [_, _], span2)) = method_call!(recv) { + inspect_for_each::check(cx, expr, span2); + } + }, + ("get_or_insert_with", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "get_or_insert"), + ("is_file", []) => filetype_is_file::check(cx, expr, recv), + ("is_none", []) => check_is_some_is_none(cx, expr, recv, false), + ("is_some", []) => check_is_some_is_none(cx, expr, recv, true), + ("map", [m_arg]) => { + if let Some((name, [recv2, args @ ..], span2)) = method_call!(recv) { + match (name, args) { + ("as_mut", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, true, msrv), + ("as_ref", []) => option_as_ref_deref::check(cx, expr, recv2, m_arg, false, msrv), + ("filter", [f_arg]) => { + filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, false) + }, + ("filter_map", [_]) => filter_map_map::check(cx, expr), + ("find", [f_arg]) => filter_map::check(cx, expr, recv2, f_arg, span2, recv, m_arg, span, true), + _ => {}, + } + } + }, + ("map_or", [def, map]) => option_map_or_none::check(cx, expr, recv, def, map), + ("next", []) => { + if let Some((name, [recv, args @ ..], _)) = method_call!(recv) { + match (name, args) { + ("filter", [arg]) => filter_next::check(cx, expr, recv, arg), + ("filter_map", [arg]) => filter_map_next::check(cx, expr, recv, arg, msrv), + ("iter", []) => iter_next_slice::check(cx, expr, recv), + ("skip", [arg]) => iter_skip_next::check(cx, expr, recv, arg), + ("skip_while", [_]) => skip_while_next::check(cx, expr), + _ => {}, + } + } + }, + ("nth", [n_arg]) => match method_call!(recv) { + Some(("bytes", [recv2], _)) => bytes_nth::check(cx, expr, recv2, n_arg), + 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), + _ => iter_nth_zero::check(cx, expr, recv, n_arg), + }, + ("ok_or_else", [arg]) => unnecessary_lazy_eval::check(cx, expr, recv, arg, "ok_or"), + ("or_else", [arg]) => { + if !bind_instead_of_map::ResultOrElseErrInfo::check(cx, expr, recv, arg) { + unnecessary_lazy_eval::check(cx, expr, recv, arg, "or"); + } + }, + ("step_by", [arg]) => iterator_step_by_zero::check(cx, expr, arg), + ("to_os_string", []) => implicit_clone::check(cx, expr, sym::OsStr), + ("to_owned", []) => implicit_clone::check(cx, expr, sym::ToOwned), + ("to_path_buf", []) => implicit_clone::check(cx, expr, sym::Path), + ("to_vec", []) => implicit_clone::check(cx, expr, sym::slice), + ("unwrap", []) => match method_call!(recv) { + Some(("get", [recv, get_arg], _)) => get_unwrap::check(cx, expr, recv, get_arg, false), + Some(("get_mut", [recv, get_arg], _)) => get_unwrap::check(cx, expr, recv, get_arg, true), + _ => unwrap_used::check(cx, expr, recv), + }, + ("unwrap_or", [u_arg]) => match method_call!(recv) { + Some((arith @ ("checked_add" | "checked_sub" | "checked_mul"), [lhs, rhs], _)) => { + manual_saturating_arithmetic::check(cx, expr, lhs, rhs, u_arg, &arith["checked_".len()..]); + }, + Some(("map", [m_recv, m_arg], span)) => { + option_map_unwrap_or::check(cx, expr, m_recv, m_arg, recv, u_arg, span) + }, + _ => {}, + }, + ("unwrap_or_else", [u_arg]) => match method_call!(recv) { + Some(("map", [recv, map_arg], _)) if map_unwrap_or::check(cx, expr, recv, map_arg, u_arg, msrv) => {}, + _ => unnecessary_lazy_eval::check(cx, expr, recv, u_arg, "unwrap_or"), + }, + _ => {}, + } + } +} + +fn check_is_some_is_none(cx: &LateContext<'_>, expr: &Expr<'_>, recv: &Expr<'_>, is_some: bool) { + if let Some((name @ ("find" | "position" | "rposition"), [f_recv, arg], span)) = method_call!(recv) { + search_is_some::check(cx, expr, name, is_some, f_recv, arg, recv, span) + } +} + /// Used for `lint_binary_expr_with_method_call`. #[derive(Copy, Clone)] struct BinaryExprInfo<'a> { |