-use rustc::hir;
-use rustc::lint::*;
-use rustc::{declare_lint, lint_array};
+// 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::rustc::hir;
+use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
+use crate::rustc::{declare_tool_lint, lint_array};
use if_chain::if_chain;
-use rustc::ty;
-use rustc_errors::Applicability;
-use syntax::codemap::Span;
+use crate::rustc::ty;
+use crate::rustc_errors::Applicability;
+use crate::syntax::source_map::Span;
use crate::utils::{in_macro, iter_input_pats, match_type, method_chain_args, snippet, span_lint_and_then};
use crate::utils::paths;
}
}
-fn is_unit_type(ty: ty::Ty) -> bool {
+fn is_unit_type(ty: ty::Ty<'_>) -> bool {
match ty.sty {
- ty::TyTuple(slice) => slice.is_empty(),
- ty::TyNever => true,
+ ty::Tuple(slice) => slice.is_empty(),
+ ty::Never => true,
_ => false,
}
}
-fn is_unit_function(cx: &LateContext, expr: &hir::Expr) -> bool {
+fn is_unit_function(cx: &LateContext<'_, '_>, expr: &hir::Expr) -> bool {
let ty = cx.tables.expr_ty(expr);
- if let ty::TyFnDef(id, _) = ty.sty {
+ if let ty::FnDef(id, _) = ty.sty {
if let Some(fn_type) = cx.tcx.fn_sig(id).no_late_bound_regions() {
return is_unit_type(fn_type.output());
}
false
}
-fn is_unit_expression(cx: &LateContext, expr: &hir::Expr) -> bool {
+fn is_unit_expression(cx: &LateContext<'_, '_>, expr: &hir::Expr) -> bool {
is_unit_type(cx.tables.expr_ty(expr))
}
/// semicolons, which causes problems when generating a suggestion. Given an
/// expression that evaluates to '()' or '!', recursively remove useless braces
/// and semi-colons until is suitable for including in the suggestion template
-fn reduce_unit_expression<'a>(cx: &LateContext, expr: &'a hir::Expr) -> Option<Span> {
+fn reduce_unit_expression<'a>(cx: &LateContext<'_, '_>, expr: &'a hir::Expr) -> Option<Span> {
if !is_unit_expression(cx, expr) {
return None;
}
None
}
-/// Builds a name for the let binding variable (var_arg)
+/// Builds a name for the let binding variable (`var_arg`)
///
/// `x.field` => `x_field`
/// `y` => `_y`
///
/// Anything else will return `_`.
-fn let_binding_name(cx: &LateContext, var_arg: &hir::Expr) -> String {
+fn let_binding_name(cx: &LateContext<'_, '_>, var_arg: &hir::Expr) -> String {
match &var_arg.node {
hir::ExprKind::Field(_, _) => snippet(cx, var_arg.span, "_").replace(".", "_"),
hir::ExprKind::Path(_) => format!("_{}", snippet(cx, var_arg.span, "")),
)
}
-fn lint_map_unit_fn(cx: &LateContext, stmt: &hir::Stmt, expr: &hir::Expr, map_args: &[hir::Expr]) {
+fn lint_map_unit_fn(cx: &LateContext<'_, '_>, stmt: &hir::Stmt, expr: &hir::Expr, map_args: &[hir::Expr]) {
let var_arg = &map_args[0];
let fn_arg = &map_args[1];
snippet(cx, binding.pat.span, "_"),
snippet(cx, var_arg.span, "_"),
snippet(cx, reduced_expr_span, "_"));
- db.span_suggestion(stmt.span, "try this", suggestion);
+ db.span_suggestion_with_applicability(
+ stmt.span,
+ "try this",
+ suggestion,
+ Applicability::MachineApplicable, // snippet
+ );
} else {
let suggestion = format!("if let {0}({1}) = {2} {{ ... }}",
variant,
snippet(cx, binding.pat.span, "_"),
snippet(cx, var_arg.span, "_"));
- db.span_suggestion_with_applicability(stmt.span,
- "try this",
- suggestion,
- Applicability::Unspecified);
+ db.span_suggestion_with_applicability(
+ stmt.span,
+ "try this",
+ suggestion,
+ Applicability::Unspecified,
+ );
}
});
}
}
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Pass {
- fn check_stmt(&mut self, cx: &LateContext, stmt: &hir::Stmt) {
+ fn check_stmt(&mut self, cx: &LateContext<'_, '_>, stmt: &hir::Stmt) {
if in_macro(stmt.span) {
return;
}
if let hir::StmtKind::Semi(ref expr, _) = stmt.node {
- if let hir::ExprKind::MethodCall(_, _, _) = expr.node {
- if let Some(arglists) = method_chain_args(expr, &["map"]) {
- lint_map_unit_fn(cx, stmt, expr, arglists[0]);
- }
+ if let Some(arglists) = method_chain_args(expr, &["map"]) {
+ lint_map_unit_fn(cx, stmt, expr, arglists[0]);
}
}
}