-use crate::utils::{differing_macro_contexts, in_macro, snippet_opt, span_note_and_lint};
-use rustc::lint::{EarlyContext, EarlyLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
-use syntax::ast;
-use syntax::ptr::P;
+use crate::utils::{differing_macro_contexts, snippet_opt, span_note_and_lint};
+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::*;
-/// **What it does:** Checks for use of the non-existent `=*`, `=!` and `=-`
-/// operators.
-///
-/// **Why is this bad?** This is either a typo of `*=`, `!=` or `-=` or
-/// confusing.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust,ignore
-/// a =- 42; // confusing, should it be `a -= 42` or `a = -42`?
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for use of the non-existent `=*`, `=!` and `=-`
+ /// operators.
+ ///
+ /// **Why is this bad?** This is either a typo of `*=`, `!=` or `-=` or
+ /// confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// a =- 42; // confusing, should it be `a -= 42` or `a = -42`?
+ /// ```
pub SUSPICIOUS_ASSIGNMENT_FORMATTING,
style,
"suspicious formatting of `*=`, `-=` or `!=`"
}
-/// **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
-/// code is correct, it might look confusing.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust,ignore
-/// if foo {
-/// } { // looks like an `else` is missing here
-/// }
-///
-/// if foo {
-/// } if bar { // looks like an `else` is missing here
-/// }
-///
-/// if foo {
-/// } else
-///
-/// { // this is the `else` block of the previous `if`, but should it be?
-/// }
-///
-/// if foo {
-/// } else
-///
-/// if bar { // this is the `else` block of the previous `if`, but should it be?
-/// }
-/// ```
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
+ /// code is correct, it might look confusing.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// if foo {
+ /// } { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } if bar { // looks like an `else` is missing here
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ ///
+ /// if foo {
+ /// } else
+ ///
+ /// if bar { // this is the `else` block of the previous `if`, but should it be?
+ /// }
+ /// ```
pub SUSPICIOUS_ELSE_FORMATTING,
style,
"suspicious formatting of `else`"
}
-/// **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.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust,ignore
-/// let a = &[
-/// -1, -2, -3 // <= no comma here
-/// -4, -5, -6
-/// ];
-/// ```
declare_clippy_lint! {
+ /// **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.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust,ignore
+ /// let a = &[
+ /// -1, -2, -3 // <= no comma here
+ /// -4, -5, -6
+ /// ];
+ /// ```
pub POSSIBLE_MISSING_COMMA,
correctness,
"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
- )
- }
-}
+declare_lint_pass!(Formatting => [
+ SUSPICIOUS_ASSIGNMENT_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)) => {
+ (&StmtKind::Expr(ref first), &StmtKind::Expr(ref second))
+ | (&StmtKind::Expr(ref first), &StmtKind::Semi(ref second)) => {
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_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.node {
+ 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.node {
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(
}
/// 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)
- {
- // workaround for rust-lang/rust#43081
- if expr.span.lo().0 == 0 && expr.span.hi().0 == 0 {
- return;
- }
-
- // 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);
-
- // 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");
-
- if else_snippet[else_pos..].contains('\n') {
- let else_desc = if unsugar_if(else_).is_some() { "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,
- ),
- );
- }
- }
+fn check_else(cx: &EarlyContext<'_>, expr: &Expr) {
+ if_chain! {
+ if let ExprKind::If(_, then, Some(else_)) = &expr.node;
+ 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);
+
+ // workaround for rust-lang/rust#43081
+ if expr.span.lo().0 != 0 && expr.span.hi().0 != 0;
+
+ // 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);
+
+ // 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 { "{..}" };
+
+ then {
+ 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,
+ ),
+ );
}
}
}
-fn has_unary_equivalent(bin_op: ast::BinOpKind) -> bool {
+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
}
/// 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.node {
for element in array {
- if let ast::ExprKind::Binary(ref op, ref lhs, _) = element.node {
+ 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) {
}
}
-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")
}
}
-fn is_block(expr: &ast::Expr) -> bool {
- if let ast::ExprKind::Block(..) = expr.node {
+fn is_block(expr: &Expr) -> bool {
+ if let ExprKind::Block(..) = expr.node {
true
} else {
false
}
}
-/// 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_) | 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 {
+ if let ExprKind::If(..) = expr.node {
+ true
+ } else {
+ false
}
}