From b0824bf75fba159f40e498dd88386174feea5cf5 Mon Sep 17 00:00:00 2001 From: Takayuki Maeda Date: Sat, 6 Mar 2021 19:31:46 +0900 Subject: [PATCH] move map_unwrap_or to its own module --- clippy_lints/src/methods/map_unwrap_or.rs | 76 +++++++++++++++++++++++ clippy_lints/src/methods/mod.rs | 75 ++-------------------- 2 files changed, 80 insertions(+), 71 deletions(-) create mode 100644 clippy_lints/src/methods/map_unwrap_or.rs diff --git a/clippy_lints/src/methods/map_unwrap_or.rs b/clippy_lints/src/methods/map_unwrap_or.rs new file mode 100644 index 000000000000..63b2cf87f32a --- /dev/null +++ b/clippy_lints/src/methods/map_unwrap_or.rs @@ -0,0 +1,76 @@ +use crate::utils::usage::mutated_variables; +use crate::utils::{is_type_diagnostic_item, meets_msrv, snippet, span_lint, span_lint_and_sugg}; +use rustc_errors::Applicability; +use rustc_hir as hir; +use rustc_lint::LateContext; +use rustc_semver::RustcVersion; +use rustc_span::symbol::sym; + +use super::MAP_UNWRAP_OR; + +const MAP_UNWRAP_OR_MSRV: RustcVersion = RustcVersion::new(1, 41, 0); + +/// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s +/// Return true if lint triggered +pub(super) fn check<'tcx>( + cx: &LateContext<'tcx>, + expr: &'tcx hir::Expr<'_>, + map_args: &'tcx [hir::Expr<'_>], + unwrap_args: &'tcx [hir::Expr<'_>], + msrv: Option<&RustcVersion>, +) -> bool { + if !meets_msrv(msrv, &MAP_UNWRAP_OR_MSRV) { + return false; + } + // lint if the caller of `map()` is an `Option` + let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::option_type); + let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::result_type); + + if is_option || is_result { + // Don't make a suggestion that may fail to compile due to mutably borrowing + // the same variable twice. + let map_mutated_vars = mutated_variables(&map_args[0], cx); + let unwrap_mutated_vars = mutated_variables(&unwrap_args[1], cx); + if let (Some(map_mutated_vars), Some(unwrap_mutated_vars)) = (map_mutated_vars, unwrap_mutated_vars) { + if map_mutated_vars.intersection(&unwrap_mutated_vars).next().is_some() { + return false; + } + } else { + return false; + } + + // lint message + let msg = if is_option { + "called `map().unwrap_or_else()` on an `Option` value. This can be done more directly by calling \ + `map_or_else(, )` instead" + } else { + "called `map().unwrap_or_else()` on a `Result` value. This can be done more directly by calling \ + `.map_or_else(, )` instead" + }; + // get snippets for args to map() and unwrap_or_else() + let map_snippet = snippet(cx, map_args[1].span, ".."); + let unwrap_snippet = snippet(cx, unwrap_args[1].span, ".."); + // lint, with note if neither arg is > 1 line and both map() and + // unwrap_or_else() have the same span + let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1; + let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt(); + if same_span && !multiline { + let var_snippet = snippet(cx, map_args[0].span, ".."); + span_lint_and_sugg( + cx, + MAP_UNWRAP_OR, + expr.span, + msg, + "try this", + format!("{}.map_or_else({}, {})", var_snippet, unwrap_snippet, map_snippet), + Applicability::MachineApplicable, + ); + return true; + } else if same_span && multiline { + span_lint(cx, MAP_UNWRAP_OR, expr.span, msg); + return true; + } + } + + false +} diff --git a/clippy_lints/src/methods/mod.rs b/clippy_lints/src/methods/mod.rs index 0c67c3b892b2..5f62942530c4 100644 --- a/clippy_lints/src/methods/mod.rs +++ b/clippy_lints/src/methods/mod.rs @@ -28,6 +28,7 @@ mod iterator_step_by_zero; mod manual_saturating_arithmetic; mod map_collect_result_unit; mod map_flatten; +mod map_unwrap_or; mod ok_expect; mod option_as_ref_deref; mod option_map_or_none; @@ -66,11 +67,10 @@ use rustc_span::symbol::{sym, Symbol, SymbolStr}; use rustc_typeck::hir_ty_to_ty; use crate::utils::eager_or_lazy::is_lazyness_candidate; -use crate::utils::usage::mutated_variables; use crate::utils::{ contains_return, contains_ty, get_trait_def_id, implements_trait, in_macro, is_copy, is_expn_of, - is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, meets_msrv, - method_calls, method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, + is_type_diagnostic_item, iter_input_pats, last_path_segment, match_def_path, match_qpath, match_type, method_calls, + method_chain_args, paths, return_ty, single_segment_path, snippet, snippet_with_applicability, snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, SpanlessEq, }; @@ -1689,7 +1689,7 @@ impl<'tcx> LateLintPass<'tcx> for Methods { ["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 !lint_map_unwrap_or_else(cx, expr, arg_lists[1], arg_lists[0], self.msrv.as_ref()) { + 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"); } }, @@ -2365,73 +2365,6 @@ fn derefs_to_slice<'tcx>( } } -const MAP_UNWRAP_OR_MSRV: RustcVersion = RustcVersion::new(1, 41, 0); - -/// lint use of `map().unwrap_or_else()` for `Option`s and `Result`s -/// Return true if lint triggered -fn lint_map_unwrap_or_else<'tcx>( - cx: &LateContext<'tcx>, - expr: &'tcx hir::Expr<'_>, - map_args: &'tcx [hir::Expr<'_>], - unwrap_args: &'tcx [hir::Expr<'_>], - msrv: Option<&RustcVersion>, -) -> bool { - if !meets_msrv(msrv, &MAP_UNWRAP_OR_MSRV) { - return false; - } - // lint if the caller of `map()` is an `Option` - let is_option = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::option_type); - let is_result = is_type_diagnostic_item(cx, cx.typeck_results().expr_ty(&map_args[0]), sym::result_type); - - if is_option || is_result { - // Don't make a suggestion that may fail to compile due to mutably borrowing - // the same variable twice. - let map_mutated_vars = mutated_variables(&map_args[0], cx); - let unwrap_mutated_vars = mutated_variables(&unwrap_args[1], cx); - if let (Some(map_mutated_vars), Some(unwrap_mutated_vars)) = (map_mutated_vars, unwrap_mutated_vars) { - if map_mutated_vars.intersection(&unwrap_mutated_vars).next().is_some() { - return false; - } - } else { - return false; - } - - // lint message - let msg = if is_option { - "called `map().unwrap_or_else()` on an `Option` value. This can be done more directly by calling \ - `map_or_else(, )` instead" - } else { - "called `map().unwrap_or_else()` on a `Result` value. This can be done more directly by calling \ - `.map_or_else(, )` instead" - }; - // get snippets for args to map() and unwrap_or_else() - let map_snippet = snippet(cx, map_args[1].span, ".."); - let unwrap_snippet = snippet(cx, unwrap_args[1].span, ".."); - // lint, with note if neither arg is > 1 line and both map() and - // unwrap_or_else() have the same span - let multiline = map_snippet.lines().count() > 1 || unwrap_snippet.lines().count() > 1; - let same_span = map_args[1].span.ctxt() == unwrap_args[1].span.ctxt(); - if same_span && !multiline { - let var_snippet = snippet(cx, map_args[0].span, ".."); - span_lint_and_sugg( - cx, - MAP_UNWRAP_OR, - expr.span, - msg, - "try this", - format!("{}.map_or_else({}, {})", var_snippet, unwrap_snippet, map_snippet), - Applicability::MachineApplicable, - ); - return true; - } else if same_span && multiline { - span_lint(cx, MAP_UNWRAP_OR, expr.span, msg); - return true; - } - } - - false -} - /// Used for `lint_binary_expr_with_method_call`. #[derive(Copy, Clone)] struct BinaryExprInfo<'a> {