-use crate::utils::{differing_macro_contexts, in_macro_or_desugar, 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 syntax::ptr::P;
+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
/// }
/// ```
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
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_or_desugar(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,
really are doing `.. = ({op} ..)`",
op = op
),
- eqop_span,
+ None,
&format!("to remove this lint, use either `{op}=` or `= {op}`", op = op),
);
}
}
}
+/// 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: &ast::Expr) {
+fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
if_chain! {
- if let Some((then, &Some(ref else_))) = unsugar_if(expr);
- if is_block(else_) || unsugar_if(else_).is_some();
+ 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 !in_macro_or_desugar(then.span) && !in_external_macro(cx.sess, expr.span);
+ if !then.span.from_expansion() && !in_external_macro(cx.sess, expr.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);
- if let Some(else_pos) = else_snippet.find("else");
- if else_snippet[else_pos..].contains('\n');
- let else_desc = if unsugar_if(else_).is_some() { "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 `{}`",
}
}
-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_or_desugar(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,
}
}
-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<ast::Block>, &Option<P<ast::Expr>>)> {
- match expr.node {
- ast::ExprKind::If(_, 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(..))
}
projects / rust.git / blobdiff