X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=clippy_lints%2Fsrc%2Fformatting.rs;h=b10e83c0ea819e5c1c891d310d6a3b7cd3288a72;hb=9f6b5de7deaf4dc9e7917370ad09ab85dc23997c;hp=08376bc49d22488283c62e08db6358cdea6ae47a;hpb=547c5c06678181ddba71f576cd79f2bce7529ca7;p=rust.git diff --git a/clippy_lints/src/formatting.rs b/clippy_lints/src/formatting.rs index 08376bc49d2..b10e83c0ea8 100644 --- a/clippy_lints/src/formatting.rs +++ b/clippy_lints/src/formatting.rs @@ -1,8 +1,12 @@ -use crate::utils::{differing_macro_contexts, in_macro, snippet_opt, span_note_and_lint}; -use rustc::lint::{in_external_macro, EarlyContext, EarlyLintPass, LintArray, LintPass}; -use rustc::{declare_tool_lint, lint_array}; -use syntax::ast; -use syntax::ptr::P; +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_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 `=-` @@ -22,6 +26,28 @@ "suspicious formatting of `*=`, `-=` or `!=`" } +declare_clippy_lint! { + /// **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. + /// + /// **Known problems:** None. + /// + /// **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, + style, + "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. @@ -78,54 +104,41 @@ "possible missing comma in array" } -#[derive(Copy, Clone)] -pub struct Formatting; - -impl LintPass for Formatting { - fn get_lints(&self) -> LintArray { - lint_array!( - SUSPICIOUS_ASSIGNMENT_FORMATTING, - SUSPICIOUS_ELSE_FORMATTING, - POSSIBLE_MISSING_COMMA - ) - } - - fn name(&self) -> &'static str { - "Formatting" - } -} +declare_lint_pass!(Formatting => [ + SUSPICIOUS_ASSIGNMENT_FORMATTING, + SUSPICIOUS_UNARY_OP_FORMATTING, + SUSPICIOUS_ELSE_FORMATTING, + POSSIBLE_MISSING_COMMA +]); impl EarlyLintPass for Formatting { - fn check_block(&mut self, cx: &EarlyContext<'_>, block: &ast::Block) { + fn check_block(&mut self, cx: &EarlyContext<'_>, block: &Block) { for w in block.stmts.windows(2) { - match (&w[0].node, &w[1].node) { - (&ast::StmtKind::Expr(ref first), &ast::StmtKind::Expr(ref second)) - | (&ast::StmtKind::Expr(ref first), &ast::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: &ast::Expr) { + 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); } } /// Implementation of the `SUSPICIOUS_ASSIGNMENT_FORMATTING` lint. -fn check_assign(cx: &EarlyContext<'_>, expr: &ast::Expr) { - if let ast::ExprKind::Assign(ref lhs, ref rhs) = expr.node { - if !differing_macro_contexts(lhs.span, rhs.span) && !in_macro(lhs.span) { +fn check_assign(cx: &EarlyContext<'_>, expr: &Expr) { + 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 ast::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 = ast::UnOp::to_string(op); + 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, @@ -134,7 +147,7 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &ast::Expr) { really are doing `.. = ({op} ..)`", op = op ), - eqop_span, + None, &format!("to remove this lint, use either `{op}=` or `= {op}`", op = op), ); } @@ -144,104 +157,145 @@ fn check_assign(cx: &EarlyContext<'_>, expr: &ast::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 a 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: &ast::Expr) { - if let Some((then, &Some(ref else_))) = unsugar_if(expr) { - if (is_block(else_) || unsugar_if(else_).is_some()) - && !differing_macro_contexts(then.span, else_.span) - && !in_macro(then.span) - && !in_external_macro(cx.sess, expr.span) - { - // workaround for rust-lang/rust#43081 - if expr.span.lo().0 == 0 && expr.span.hi().0 == 0 { - return; - } +fn check_else(cx: &EarlyContext<'_>, expr: &Expr) { + if_chain! { + 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); - // this will be a span from the closing ‘}’ of the “then” block (excluding) to - // the - // “if” of the “else if” block (excluding) - let else_span = then.span.between(else_.span); + // workaround for rust-lang/rust#43081 + if expr.span.lo().0 != 0 && expr.span.hi().0 != 0; - // 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) { - let else_pos = else_snippet.find("else").expect("there must be a `else` here"); + // this will be a span from the closing ‘}’ of the “then” block (excluding) to + // the “if” of the “else if” block (excluding) + let else_span = then.span.between(else_.span); - if else_snippet[else_pos..].contains('\n') { - let else_desc = if unsugar_if(else_).is_some() { "if" } else { "{..}" }; + // 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 { "{..}" }; - span_note_and_lint( - cx, - SUSPICIOUS_ELSE_FORMATTING, - else_span, - &format!("this is an `else {}` but the formatting might hide it", else_desc), - else_span, - &format!( - "to remove this lint, remove the `else` or remove the new line between \ - `else` and `{}`", - else_desc, - ), - ); - } - } + then { + span_lint_and_note( + cx, + SUSPICIOUS_ELSE_FORMATTING, + else_span, + &format!("this is an `else {}` but the formatting might hide it", else_desc), + None, + &format!( + "to remove this lint, remove the `else` or remove the new line between \ + `else` and `{}`", + else_desc, + ), + ); } } } -fn has_unary_equivalent(bin_op: ast::BinOpKind) -> bool { +#[must_use] +fn has_unary_equivalent(bin_op: BinOpKind) -> bool { // &, *, - - bin_op == ast::BinOpKind::And || bin_op == ast::BinOpKind::Mul || bin_op == ast::BinOpKind::Sub + 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: &ast::Expr) { - if let ast::ExprKind::Array(ref array) = expr.node { +fn check_array(cx: &EarlyContext<'_>, expr: &Expr) { + if let ExprKind::Array(ref array) = expr.kind { for element in array { - if let ast::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", + ); } } } } } -fn check_missing_else(cx: &EarlyContext<'_>, first: &ast::Expr, second: &ast::Expr) { +fn check_missing_else(cx: &EarlyContext<'_>, first: &Expr, second: &Expr) { if !differing_macro_contexts(first.span, second.span) - && !in_macro(first.span) - && unsugar_if(first).is_some() - && (is_block(second) || unsugar_if(second).is_some()) + && !first.span.from_expansion() + && is_if(first) + && (is_block(second) || is_if(second)) { // where the else would be let else_span = first.span.between(second.span); if let Some(else_snippet) = snippet_opt(cx, else_span) { if !else_snippet.contains('\n') { - let (looks_like, next_thing) = if unsugar_if(second).is_some() { + let (looks_like, next_thing) = if is_if(second) { ("an `else if`", "the second `if`") } else { ("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, @@ -252,20 +306,11 @@ fn check_missing_else(cx: &EarlyContext<'_>, first: &ast::Expr, second: &ast::Ex } } -fn is_block(expr: &ast::Expr) -> bool { - if let ast::ExprKind::Block(..) = expr.node { - true - } else { - false - } +fn is_block(expr: &Expr) -> bool { + matches!(expr.kind, ExprKind::Block(..)) } -/// Match `if` or `if let` expressions and return the `then` and `else` block. -fn unsugar_if(expr: &ast::Expr) -> Option<(&P, &Option>)> { - match expr.node { - ast::ExprKind::If(_, ref then, ref else_) | ast::ExprKind::IfLet(_, _, ref then, ref else_) => { - Some((then, else_)) - }, - _ => None, - } +/// Check if the expression is an `if` or `if let` +fn is_if(expr: &Expr) -> bool { + matches!(expr.kind, ExprKind::If(..)) }