-// Copyright 2014-2018 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
use crate::utils::*;
use matches::matches;
-use rustc::hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
-use rustc::hir::*;
-use rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
-use rustc::{declare_tool_lint, lint_array};
+use rustc::hir::map::Map;
+use rustc::lint::in_external_macro;
+use rustc_errors::Applicability;
+use rustc_hir::intravisit::{walk_expr, NestedVisitorMap, Visitor};
+use rustc_hir::*;
+use rustc_lint::{LateContext, LateLintPass, LintContext};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
-/// **What it does:** Checks for `if` conditions that use blocks to contain an
-/// expression.
-///
-/// **Why is this bad?** It isn't really Rust style, same as using parentheses
-/// to contain expressions.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// if { true } ..
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `if` conditions that use blocks to contain an
+ /// expression.
+ ///
+ /// **Why is this bad?** It isn't really Rust style, same as using parentheses
+ /// to contain expressions.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```rust
+ /// if { true } { /* ... */ }
+ /// ```
pub BLOCK_IN_IF_CONDITION_EXPR,
style,
- "braces that can be eliminated in conditions, e.g. `if { true } ...`"
+ "braces that can be eliminated in conditions, e.g., `if { true } ...`"
}
-/// **What it does:** Checks for `if` conditions that use blocks containing
-/// statements, or conditions that use closures with blocks.
-///
-/// **Why is this bad?** Using blocks in the condition makes it hard to read.
-///
-/// **Known problems:** None.
-///
-/// **Example:**
-/// ```rust
-/// if { let x = somefunc(); x } ..
-/// // or
-/// if somefunc(|x| { x == 47 }) ..
-/// ```
declare_clippy_lint! {
+ /// **What it does:** Checks for `if` conditions that use blocks containing
+ /// statements, or conditions that use closures with blocks.
+ ///
+ /// **Why is this bad?** Using blocks in the condition makes it hard to read.
+ ///
+ /// **Known problems:** None.
+ ///
+ /// **Example:**
+ /// ```ignore
+ /// if { let x = somefunc(); x } {}
+ /// // or
+ /// if somefunc(|x| { x == 47 }) {}
+ /// ```
pub BLOCK_IN_IF_CONDITION_STMT,
style,
- "complex blocks in conditions, e.g. `if { let x = true; x } ...`"
+ "complex blocks in conditions, e.g., `if { let x = true; x } ...`"
}
-#[derive(Copy, Clone)]
-pub struct BlockInIfCondition;
-
-impl LintPass for BlockInIfCondition {
- fn get_lints(&self) -> LintArray {
- lint_array!(BLOCK_IN_IF_CONDITION_EXPR, BLOCK_IN_IF_CONDITION_STMT)
- }
-}
+declare_lint_pass!(BlockInIfCondition => [BLOCK_IN_IF_CONDITION_EXPR, BLOCK_IN_IF_CONDITION_STMT]);
-struct ExVisitor<'a, 'tcx: 'a> {
- found_block: Option<&'tcx Expr>,
+struct ExVisitor<'a, 'tcx> {
+ found_block: Option<&'tcx Expr<'tcx>>,
cx: &'a LateContext<'a, 'tcx>,
}
-impl<'a, 'tcx: 'a> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
- fn visit_expr(&mut self, expr: &'tcx Expr) {
- if let ExprKind::Closure(_, _, eid, _, _) = expr.node {
+impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
+ type Map = Map<'tcx>;
+
+ fn visit_expr(&mut self, expr: &'tcx Expr<'tcx>) {
+ if let ExprKind::Closure(_, _, eid, _, _) = expr.kind {
let body = self.cx.tcx.hir().body(eid);
let ex = &body.value;
- if matches!(ex.node, ExprKind::Block(_, _)) && !in_macro(body.value.span) {
+ if matches!(ex.kind, ExprKind::Block(_, _)) && !body.value.span.from_expansion() {
self.found_block = Some(ex);
return;
}
}
walk_expr(self, expr);
}
- fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
+ fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
NestedVisitorMap::None
}
}
const BRACED_EXPR_MESSAGE: &str = "omit braces around single expression condition";
-const COMPLEX_BLOCK_MESSAGE: &str = "in an 'if' condition, avoid complex blocks or closures with blocks; \
- instead, move the block or closure higher and bind it with a 'let'";
+const COMPLEX_BLOCK_MESSAGE: &str = "in an `if` condition, avoid complex blocks or closures with blocks; \
+ instead, move the block or closure higher and bind it with a `let`";
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for BlockInIfCondition {
- fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
- if let ExprKind::If(check, then, _) = &expr.node {
- if let ExprKind::Block(block, _) = &check.node {
- if block.rules == DefaultBlock {
+ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr<'_>) {
+ if in_external_macro(cx.sess(), expr.span) {
+ return;
+ }
+ if let Some((cond, _, _)) = higher::if_block(&expr) {
+ if let ExprKind::Block(block, _) = &cond.kind {
+ if block.rules == BlockCheckMode::DefaultBlock {
if block.stmts.is_empty() {
if let Some(ex) = &block.expr {
// don't dig into the expression here, just suggest that they remove
// the block
- if in_macro(expr.span) || differing_macro_contexts(expr.span, ex.span) {
+ if expr.span.from_expansion() || differing_macro_contexts(expr.span, ex.span) {
return;
}
- span_help_and_lint(
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
cx,
BLOCK_IN_IF_CONDITION_EXPR,
- check.span,
+ cond.span,
BRACED_EXPR_MESSAGE,
- &format!(
- "try\nif {} {} ... ",
- snippet_block(cx, ex.span, ".."),
- snippet_block(cx, then.span, "..")
+ "try",
+ format!(
+ "{}",
+ snippet_block_with_applicability(
+ cx,
+ ex.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ )
),
+ applicability,
);
}
} else {
let span = block.expr.as_ref().map_or_else(|| block.stmts[0].span, |e| e.span);
- if in_macro(span) || differing_macro_contexts(expr.span, span) {
+ if span.from_expansion() || differing_macro_contexts(expr.span, span) {
return;
}
// move block higher
- span_help_and_lint(
+ let mut applicability = Applicability::MachineApplicable;
+ span_lint_and_sugg(
cx,
BLOCK_IN_IF_CONDITION_STMT,
- check.span,
+ expr.span.with_hi(cond.span.hi()),
COMPLEX_BLOCK_MESSAGE,
- &format!(
- "try\nlet res = {};\nif res {} ... ",
- snippet_block(cx, block.span, ".."),
- snippet_block(cx, then.span, "..")
+ "try",
+ format!(
+ "let res = {}; if res",
+ snippet_block_with_applicability(
+ cx,
+ block.span,
+ "..",
+ Some(expr.span),
+ &mut applicability
+ ),
),
+ applicability,
);
}
}
} else {
let mut visitor = ExVisitor { found_block: None, cx };
- walk_expr(&mut visitor, check);
+ walk_expr(&mut visitor, cond);
if let Some(block) = visitor.found_block {
span_lint(cx, BLOCK_IN_IF_CONDITION_STMT, block.span, COMPLEX_BLOCK_MESSAGE);
}
projects / rust.git / blobdiff