X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fformatting.rs;h=4dd0ffe77ea49fbff542b3c20a48ad053aa94650;hb=e6455ea72ca3a4602f6a6b097cb80647a1f69388;hp=463530211157e9fd5e16f9d23f6423fc10e96312;hpb=204b2f365864c304bcf510adeba77741653a7edf;p=rust.git diff --git a/clippy_lints/src/formatting.rs b/clippy_lints/src/formatting.rs index 46353021115..4dd0ffe77ea 100644 --- a/clippy_lints/src/formatting.rs +++ b/clippy_lints/src/formatting.rs @@ -1,37 +1,63 @@ -use crate::utils::{differing_macro_contexts, snippet_opt, span_note_and_lint}; +use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_note}; +use clippy_utils::differing_macro_contexts; +use clippy_utils::source::snippet_opt; use if_chain::if_chain; -use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintPass}; -use rustc::{declare_lint_pass, declare_tool_lint}; -use syntax::ast::*; +use rustc_ast::ast::{BinOpKind, Block, Expr, ExprKind, StmtKind, UnOp}; +use rustc_lint::{EarlyContext, EarlyLintPass}; +use rustc_middle::lint::in_external_macro; +use rustc_session::{declare_lint_pass, declare_tool_lint}; +use rustc_span::source_map::Span; declare_clippy_lint! { - /// **What it does:** Checks for use of the non-existent `=*`, `=!` and `=-` + /// ### What it does + /// Checks for use of the non-existent `=*`, `=!` and `=-` /// operators. /// - /// **Why is this bad?** This is either a typo of `*=`, `!=` or `-=` or + /// ### Why is this bad? + /// This is either a typo of `*=`, `!=` or `-=` or /// confusing. /// - /// **Known problems:** None. - /// - /// **Example:** + /// ### Example /// ```rust,ignore /// a =- 42; // confusing, should it be `a -= 42` or `a = -42`? /// ``` pub SUSPICIOUS_ASSIGNMENT_FORMATTING, - style, + suspicious, "suspicious formatting of `*=`, `-=` or `!=`" } declare_clippy_lint! { - /// **What it does:** Checks for formatting of `else`. It lints if the `else` + /// ### What it does + /// Checks the formatting of a unary operator on the right hand side + /// of a binary operator. It lints if there is no space between the binary and unary operators, + /// but there is a space between the unary and its operand. + /// + /// ### Why is this bad? + /// This is either a typo in the binary operator or confusing. + /// + /// ### Example + /// ```rust,ignore + /// if foo <- 30 { // this should be `foo < -30` but looks like a different operator + /// } + /// + /// if foo &&! bar { // this should be `foo && !bar` but looks like a different operator + /// } + /// ``` + pub SUSPICIOUS_UNARY_OP_FORMATTING, + suspicious, + "suspicious formatting of unary `-` or `!` on the RHS of a BinOp" +} + +declare_clippy_lint! { + /// ### What it does + /// Checks for formatting of `else`. It lints if the `else` /// is followed immediately by a newline or the `else` seems to be missing. /// - /// **Why is this bad?** This is probably some refactoring remnant, even if the + /// ### Why is this bad? + /// This is probably some refactoring remnant, even if the /// code is correct, it might look confusing. /// - /// **Known problems:** None. - /// - /// **Example:** + /// ### Example /// ```rust,ignore /// if foo { /// } { // looks like an `else` is missing here @@ -54,19 +80,19 @@ /// } /// ``` pub SUSPICIOUS_ELSE_FORMATTING, - style, + suspicious, "suspicious formatting of `else`" } declare_clippy_lint! { - /// **What it does:** Checks for possible missing comma in an array. It lints if + /// ### What it does + /// Checks for possible missing comma in an array. It lints if /// an array element is a binary operator expression and it lies on two lines. /// - /// **Why is this bad?** This could lead to unexpected results. + /// ### Why is this bad? + /// This could lead to unexpected results. /// - /// **Known problems:** None. - /// - /// **Example:** + /// ### Example /// ```rust,ignore /// let a = &[ /// -1, -2, -3 // <= no comma here @@ -80,6 +106,7 @@ declare_lint_pass!(Formatting => [ SUSPICIOUS_ASSIGNMENT_FORMATTING, + SUSPICIOUS_UNARY_OP_FORMATTING, SUSPICIOUS_ELSE_FORMATTING, POSSIBLE_MISSING_COMMA ]); @@ -87,18 +114,15 @@ impl EarlyLintPass for Formatting { fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) { for w in block.stmts.windows(2) { - match (&w[0].node, &w[1].node) { - (&StmtKind::Expr(ref first), &StmtKind::Expr(ref second)) - | (&StmtKind::Expr(ref first), &StmtKind::Semi(ref second)) => { - check_missing_else(cx, first, second); - }, - _ => (), + if let (StmtKind::Expr(first), StmtKind::Expr(second) | StmtKind::Semi(second)) = (&w[0].kind, &w[1].kind) { + check_missing_else(cx, first, second); } } } fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) { check_assign(cx, expr); + check_unop(cx, expr); check_else(cx, expr); check_array(cx, expr); } @@ -106,15 +130,15 @@ fn check_expr(&mut self, cx: &EarlyContext<'_>, expr: &Expr) { /// Implementation of the `SUSPICIOUS_ASSIGNMENT_FORMATTING` lint. fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) { - if let ExprKind::Assign(ref lhs, ref rhs) = expr.node { + if let ExprKind::Assign(ref lhs, ref rhs, _) = expr.kind { if !differing_macro_contexts(lhs.span, rhs.span) && !lhs.span.from_expansion() { let eq_span = lhs.span.between(rhs.span); - if let ExprKind::Unary(op, ref sub_rhs) = rhs.node { + if let ExprKind::Unary(op, ref sub_rhs) = rhs.kind { if let Some(eq_snippet) = snippet_opt(cx, eq_span) { let op = UnOp::to_string(op); let eqop_span = lhs.span.between(sub_rhs.span); if eq_snippet.ends_with('=') { - span_note_and_lint( + span_lint_and_note( cx, SUSPICIOUS_ASSIGNMENT_FORMATTING, eqop_span, @@ -123,7 +147,7 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) { really are doing `.. = ({op} ..)`", op = op ), - eqop_span, + None, &format!("to remove this lint, use either `{op}=` or `= {op}`", op = op), ); } @@ -133,10 +157,50 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) { } } +/// Implementation of the `SUSPICIOUS_UNARY_OP_FORMATTING` lint. +fn check_unop(cx: &EarlyContext<'_>, expr: &Expr) { + if_chain! { + if let ExprKind::Binary(ref binop, ref lhs, ref rhs) = expr.kind; + if !differing_macro_contexts(lhs.span, rhs.span) && !lhs.span.from_expansion(); + // span between BinOp LHS and RHS + let binop_span = lhs.span.between(rhs.span); + // if RHS is an UnOp + if let ExprKind::Unary(op, ref un_rhs) = rhs.kind; + // from UnOp operator to UnOp operand + let unop_operand_span = rhs.span.until(un_rhs.span); + if let Some(binop_snippet) = snippet_opt(cx, binop_span); + if let Some(unop_operand_snippet) = snippet_opt(cx, unop_operand_span); + let binop_str = BinOpKind::to_string(&binop.node); + // no space after BinOp operator and space after UnOp operator + if binop_snippet.ends_with(binop_str) && unop_operand_snippet.ends_with(' '); + then { + let unop_str = UnOp::to_string(op); + let eqop_span = lhs.span.between(un_rhs.span); + span_lint_and_help( + cx, + SUSPICIOUS_UNARY_OP_FORMATTING, + eqop_span, + &format!( + "by not having a space between `{binop}` and `{unop}` it looks like \ + `{binop}{unop}` is a single operator", + binop = binop_str, + unop = unop_str + ), + None, + &format!( + "put a space between `{binop}` and `{unop}` and remove the space after `{unop}`", + binop = binop_str, + unop = unop_str + ), + ); + } + } +} + /// Implementation of the `SUSPICIOUS_ELSE_FORMATTING` lint for weird `else`. fn check_else(cx: &EarlyContext<'_>, expr: &Expr) { if_chain! { - if let ExprKind::If(_, then, Some(else_)) = &expr.node; + if let ExprKind::If(_, then, Some(else_)) = &expr.kind; if is_block(else_) || is_if(else_); if !differing_macro_contexts(then.span, else_.span); if !then.span.from_expansion() && !in_external_macro(cx.sess, expr.span); @@ -151,17 +215,29 @@ fn check_else(cx: &EarlyContext<'_>, expr: &Expr) { // the snippet should look like " else \n " with maybe comments anywhere // it’s bad when there is a ‘\n’ after the “else” if let Some(else_snippet) = snippet_opt(cx, else_span); - if let Some(else_pos) = else_snippet.find("else"); - if else_snippet[else_pos..].contains('\n'); - let else_desc = if is_if(else_) { "if" } else { "{..}" }; + if let Some((pre_else, post_else)) = else_snippet.split_once("else"); + if let Some((_, post_else_post_eol)) = post_else.split_once('\n'); then { - span_note_and_lint( + // Allow allman style braces `} \n else \n {` + if_chain! { + if is_block(else_); + if let Some((_, pre_else_post_eol)) = pre_else.split_once('\n'); + // Exactly one eol before and after the else + if !pre_else_post_eol.contains('\n'); + if !post_else_post_eol.contains('\n'); + then { + return; + } + } + + let else_desc = if is_if(else_) { "if" } else { "{..}" }; + span_lint_and_note( cx, SUSPICIOUS_ELSE_FORMATTING, else_span, &format!("this is an `else {}` but the formatting might hide it", else_desc), - else_span, + None, &format!( "to remove this lint, remove the `else` or remove the new line between \ `else` and `{}`", @@ -172,31 +248,37 @@ fn check_else(cx: &EarlyContext<'_>, expr: &Expr) { } } +#[must_use] fn has_unary_equivalent(bin_op: BinOpKind) -> bool { // &, *, - bin_op == BinOpKind::And || bin_op == BinOpKind::Mul || bin_op == BinOpKind::Sub } +fn indentation(cx: &EarlyContext<'_>, span: Span) -> usize { + cx.sess.source_map().lookup_char_pos(span.lo()).col.0 +} + /// Implementation of the `POSSIBLE_MISSING_COMMA` lint for array fn check_array(cx: &EarlyContext<'_>, expr: &Expr) { - if let ExprKind::Array(ref array) = expr.node { + if let ExprKind::Array(ref array) = expr.kind { for element in array { - if let ExprKind::Binary(ref op, ref lhs, _) = element.node { - if has_unary_equivalent(op.node) && !differing_macro_contexts(lhs.span, op.span) { - let space_span = lhs.span.between(op.span); - if let Some(space_snippet) = snippet_opt(cx, space_span) { - let lint_span = lhs.span.with_lo(lhs.span.hi()); - if space_snippet.contains('\n') { - span_note_and_lint( - cx, - POSSIBLE_MISSING_COMMA, - lint_span, - "possibly missing a comma here", - lint_span, - "to remove this lint, add a comma or write the expr in a single line", - ); - } - } + if_chain! { + if let ExprKind::Binary(ref op, ref lhs, _) = element.kind; + if has_unary_equivalent(op.node) && !differing_macro_contexts(lhs.span, op.span); + let space_span = lhs.span.between(op.span); + if let Some(space_snippet) = snippet_opt(cx, space_span); + let lint_span = lhs.span.with_lo(lhs.span.hi()); + if space_snippet.contains('\n'); + if indentation(cx, op.span) <= indentation(cx, lhs.span); + then { + span_lint_and_note( + cx, + POSSIBLE_MISSING_COMMA, + lint_span, + "possibly missing a comma here", + None, + "to remove this lint, add a comma or write the expr in a single line", + ); } } } @@ -220,12 +302,12 @@ fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) { ("an `else {..}`", "the next block") }; - span_note_and_lint( + span_lint_and_note( cx, SUSPICIOUS_ELSE_FORMATTING, else_span, &format!("this looks like {} but the `else` is missing", looks_like), - else_span, + None, &format!( "to remove this lint, add the missing `else` or add a new line before {}", next_thing, @@ -237,18 +319,10 @@ fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) { } fn is_block(expr: &Expr) -> bool { - if let ExprKind::Block(..) = expr.node { - true - } else { - false - } + matches!(expr.kind, ExprKind::Block(..)) } /// Check if the expression is an `if` or `if let` fn is_if(expr: &Expr) -> bool { - if let ExprKind::If(..) = expr.node { - true - } else { - false - } + matches!(expr.kind, ExprKind::If(..)) }