From 2ecc2ac864739cff6aed2609021e2467dedb117a Mon Sep 17 00:00:00 2001 From: Tim Nielens Date: Fri, 21 Aug 2020 00:07:56 +0200 Subject: [PATCH] unit-arg - improve suggestion --- clippy_lints/src/types.rs | 88 +++++++++++--------- tests/ui/unit_arg.rs | 7 +- tests/ui/unit_arg.stderr | 111 ++++++++++++-------------- tests/ui/unit_arg_empty_blocks.stderr | 21 ++--- 4 files changed, 115 insertions(+), 112 deletions(-) diff --git a/clippy_lints/src/types.rs b/clippy_lints/src/types.rs index 7e9190bef5e7..3f5b3a5bcd5d 100644 --- a/clippy_lints/src/types.rs +++ b/clippy_lints/src/types.rs @@ -11,8 +11,8 @@ use rustc_hir as hir; use rustc_hir::intravisit::{walk_body, walk_expr, walk_ty, FnKind, NestedVisitorMap, Visitor}; use rustc_hir::{ BinOpKind, Block, Body, Expr, ExprKind, FnDecl, FnRetTy, FnSig, GenericArg, GenericParamKind, HirId, ImplItem, - ImplItemKind, Item, ItemKind, Lifetime, Local, MatchSource, MutTy, Mutability, QPath, Stmt, StmtKind, TraitFn, - TraitItem, TraitItemKind, TyKind, UnOp, + ImplItemKind, Item, ItemKind, Lifetime, Local, MatchSource, MutTy, Mutability, Node, QPath, Stmt, StmtKind, + TraitFn, TraitItem, TraitItemKind, TyKind, UnOp, }; use rustc_lint::{LateContext, LateLintPass, LintContext}; use rustc_middle::hir::map::Map; @@ -29,10 +29,10 @@ use rustc_typeck::hir_ty_to_ty; use crate::consts::{constant, Constant}; use crate::utils::paths; use crate::utils::{ - clip, comparisons, differing_macro_contexts, higher, in_constant, indent_of, int_bits, is_type_diagnostic_item, + clip, comparisons, differing_macro_contexts, higher, in_constant, int_bits, is_type_diagnostic_item, last_path_segment, match_def_path, match_path, method_chain_args, multispan_sugg, numeric_literal::NumericLiteral, - qpath_res, sext, snippet, snippet_block_with_applicability, snippet_opt, snippet_with_applicability, - snippet_with_macro_callsite, span_lint, span_lint_and_help, span_lint_and_sugg, span_lint_and_then, unsext, + qpath_res, sext, snippet, snippet_opt, snippet_with_applicability, snippet_with_macro_callsite, span_lint, + span_lint_and_help, span_lint_and_sugg, span_lint_and_then, unsext, }; declare_clippy_lint! { @@ -844,43 +844,54 @@ fn lint_unit_args(cx: &LateContext<'_>, expr: &Expr<'_>, args_to_recover: &[&Exp Applicability::MaybeIncorrect, ); or = "or "; + applicability = Applicability::MaybeIncorrect; }); - let sugg = args_to_recover + + let arg_snippets: Vec = args_to_recover + .iter() + .filter_map(|arg| snippet_opt(cx, arg.span)) + .collect(); + let arg_snippets_without_empty_blocks: Vec = args_to_recover .iter() .filter(|arg| !is_empty_block(arg)) - .enumerate() - .map(|(i, arg)| { - let indent = if i == 0 { - 0 - } else { - indent_of(cx, expr.span).unwrap_or(0) - }; - format!( - "{}{};", - " ".repeat(indent), - snippet_block_with_applicability(cx, arg.span, "..", Some(expr.span), &mut applicability) - ) - }) - .collect::>(); - let mut and = ""; - if !sugg.is_empty() { - let plural = if sugg.len() > 1 { "s" } else { "" }; - db.span_suggestion( - expr.span.with_hi(expr.span.lo()), - &format!("{}move the expression{} in front of the call...", or, plural), - format!("{}\n", sugg.join("\n")), - applicability, - ); - and = "...and " + .filter_map(|arg| snippet_opt(cx, arg.span)) + .collect(); + + if let Some(mut sugg) = snippet_opt(cx, expr.span) { + arg_snippets.iter().for_each(|arg| { + sugg = sugg.replacen(arg, "()", 1); + }); + sugg = format!("{}{}{}", arg_snippets_without_empty_blocks.join("; "), "; ", sugg); + let parent_node = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(expr.hir_id)); + if !matches!(parent_node, Some(Node::Block(_))) && !matches!(parent_node, Some(Node::Stmt(_))) { + // expr is not in a block statement or result expression position, wrap in a block + sugg = format!("{{ {} }}", sugg); + } + + if arg_snippets_without_empty_blocks.is_empty() { + db.multipart_suggestion( + &format!("use {}unit literal{} instead", singular, plural), + args_to_recover + .iter() + .map(|arg| (arg.span, "()".to_string())) + .collect::>(), + applicability, + ); + } else { + let plural = arg_snippets_without_empty_blocks.len() > 1; + let empty_or_s = if plural { "s" } else { "" }; + let it_or_them = if plural { "them" } else { "it" }; + db.span_suggestion( + expr.span, + &format!( + "{}move the expression{} in front of the call and replace {} with the unit literal `()`", + or, empty_or_s, it_or_them + ), + sugg, + applicability, + ); + } } - db.multipart_suggestion( - &format!("{}use {}unit literal{} instead", and, singular, plural), - args_to_recover - .iter() - .map(|arg| (arg.span, "()".to_string())) - .collect::>(), - applicability, - ); }, ); } @@ -2055,6 +2066,7 @@ impl PartialOrd for FullInt { }) } } + impl Ord for FullInt { #[must_use] fn cmp(&self, other: &Self) -> Ordering { diff --git a/tests/ui/unit_arg.rs b/tests/ui/unit_arg.rs index 2992abae775b..2e2bd054e42a 100644 --- a/tests/ui/unit_arg.rs +++ b/tests/ui/unit_arg.rs @@ -1,5 +1,5 @@ #![warn(clippy::unit_arg)] -#![allow(clippy::no_effect, unused_must_use, unused_variables)] +#![allow(clippy::no_effect, unused_must_use, unused_variables, clippy::unused_unit)] use std::fmt::Debug; @@ -47,6 +47,11 @@ fn bad() { foo(3); }, ); + // here Some(foo(2)) isn't the top level statement expression, wrap the suggestion in a block + None.or(Some(foo(2))); + // in this case, the suggestion can be inlined, no need for a surrounding block + // foo(()); foo(()) instead of { foo(()); foo(()) } + foo(foo(())) } fn ok() { diff --git a/tests/ui/unit_arg.stderr b/tests/ui/unit_arg.stderr index 56f6a855dfa5..2a0cc1f18e27 100644 --- a/tests/ui/unit_arg.stderr +++ b/tests/ui/unit_arg.stderr @@ -11,16 +11,12 @@ help: remove the semicolon from the last statement in the block | LL | 1 | -help: or move the expression in front of the call... +help: or move the expression in front of the call and replace it with the unit literal `()` | LL | { LL | 1; -LL | }; +LL | }; foo(()); | -help: ...and use a unit literal instead - | -LL | foo(()); - | ^^ error: passing a unit value to a function --> $DIR/unit_arg.rs:26:5 @@ -28,14 +24,10 @@ error: passing a unit value to a function LL | foo(foo(1)); | ^^^^^^^^^^^ | -help: move the expression in front of the call... - | -LL | foo(1); +help: move the expression in front of the call and replace it with the unit literal `()` | -help: ...and use a unit literal instead - | -LL | foo(()); - | ^^ +LL | foo(1); foo(()); + | ^^^^^^^^^^^^^^^ error: passing a unit value to a function --> $DIR/unit_arg.rs:27:5 @@ -50,17 +42,13 @@ help: remove the semicolon from the last statement in the block | LL | foo(2) | -help: or move the expression in front of the call... +help: or move the expression in front of the call and replace it with the unit literal `()` | LL | { LL | foo(1); LL | foo(2); -LL | }; - | -help: ...and use a unit literal instead +LL | }; foo(()); | -LL | foo(()); - | ^^ error: passing a unit value to a function --> $DIR/unit_arg.rs:32:5 @@ -74,16 +62,12 @@ help: remove the semicolon from the last statement in the block | LL | 1 | -help: or move the expression in front of the call... +help: or move the expression in front of the call and replace it with the unit literal `()` | LL | { LL | 1; -LL | }; +LL | }; b.bar(()); | -help: ...and use a unit literal instead - | -LL | b.bar(()); - | ^^ error: passing unit values to a function --> $DIR/unit_arg.rs:35:5 @@ -91,15 +75,10 @@ error: passing unit values to a function LL | taking_multiple_units(foo(0), foo(1)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | -help: move the expressions in front of the call... - | -LL | foo(0); -LL | foo(1); - | -help: ...and use unit literals instead +help: move the expressions in front of the call and replace them with the unit literal `()` | -LL | taking_multiple_units((), ()); - | ^^ ^^ +LL | foo(0); foo(1); taking_multiple_units((), ()); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: passing unit values to a function --> $DIR/unit_arg.rs:36:5 @@ -114,18 +93,13 @@ help: remove the semicolon from the last statement in the block | LL | foo(2) | -help: or move the expressions in front of the call... +help: or move the expressions in front of the call and replace them with the unit literal `()` | -LL | foo(0); -LL | { +LL | foo(0); { LL | foo(1); LL | foo(2); -LL | }; - | -help: ...and use unit literals instead +LL | }; taking_multiple_units((), ()); | -LL | taking_multiple_units((), ()); - | ^^ ^^ error: passing unit values to a function --> $DIR/unit_arg.rs:40:5 @@ -147,35 +121,56 @@ help: remove the semicolon from the last statement in the block | LL | foo(3) | -help: or move the expressions in front of the call... +help: or move the expressions in front of the call and replace them with the unit literal `()` | LL | { -LL | foo(0); -LL | foo(1); -LL | }; -LL | { -LL | foo(2); +LL | foo(0); +LL | foo(1); +LL | }; { +LL | foo(2); +LL | foo(3); ... -help: ...and use unit literals instead + +error: use of `or` followed by a function call + --> $DIR/unit_arg.rs:51:10 | -LL | (), -LL | (), +LL | None.or(Some(foo(2))); + | ^^^^^^^^^^^^^^^^ help: try this: `or_else(|| Some(foo(2)))` | + = note: `-D clippy::or-fun-call` implied by `-D warnings` error: passing a unit value to a function - --> $DIR/unit_arg.rs:82:5 + --> $DIR/unit_arg.rs:51:13 | -LL | Some(foo(1)) +LL | None.or(Some(foo(2))); + | ^^^^^^^^^^^^ + | +help: move the expression in front of the call and replace it with the unit literal `()` + | +LL | None.or({ foo(2); Some(()) }); + | ^^^^^^^^^^^^^^^^^^^^ + +error: passing a unit value to a function + --> $DIR/unit_arg.rs:54:5 + | +LL | foo(foo(())) | ^^^^^^^^^^^^ | -help: move the expression in front of the call... +help: move the expression in front of the call and replace it with the unit literal `()` + | +LL | foo(()); foo(()) + | + +error: passing a unit value to a function + --> $DIR/unit_arg.rs:87:5 + | +LL | Some(foo(1)) + | ^^^^^^^^^^^^ | -LL | foo(1); +help: move the expression in front of the call and replace it with the unit literal `()` | -help: ...and use a unit literal instead +LL | foo(1); Some(()) | -LL | Some(()) - | ^^ -error: aborting due to 8 previous errors +error: aborting due to 11 previous errors diff --git a/tests/ui/unit_arg_empty_blocks.stderr b/tests/ui/unit_arg_empty_blocks.stderr index bb58483584b3..4cbbc8b8cd43 100644 --- a/tests/ui/unit_arg_empty_blocks.stderr +++ b/tests/ui/unit_arg_empty_blocks.stderr @@ -22,14 +22,10 @@ error: passing unit values to a function LL | taking_two_units({}, foo(0)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | -help: move the expression in front of the call... +help: move the expression in front of the call and replace it with the unit literal `()` | -LL | foo(0); - | -help: ...and use unit literals instead - | -LL | taking_two_units((), ()); - | ^^ ^^ +LL | foo(0); taking_two_units((), ()); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: passing unit values to a function --> $DIR/unit_arg_empty_blocks.rs:18:5 @@ -37,15 +33,10 @@ error: passing unit values to a function LL | taking_three_units({}, foo(0), foo(1)); | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | -help: move the expressions in front of the call... - | -LL | foo(0); -LL | foo(1); - | -help: ...and use unit literals instead +help: move the expressions in front of the call and replace them with the unit literal `()` | -LL | taking_three_units((), (), ()); - | ^^ ^^ ^^ +LL | foo(0); foo(1); taking_three_units((), (), ()); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ error: aborting due to 4 previous errors