diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7885bdfb12c..d9a198f8243 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2519,6 +2519,7 @@ Released 2018-09-13
[`unnecessary_lazy_evaluations`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_lazy_evaluations
[`unnecessary_mut_passed`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_mut_passed
[`unnecessary_operation`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_operation
+[`unnecessary_self_imports`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_self_imports
[`unnecessary_sort_by`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_sort_by
[`unnecessary_unwrap`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_unwrap
[`unnecessary_wraps`]: https://rust-lang.github.io/rust-clippy/master/index.html#unnecessary_wraps
diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs
index 78a95b00403..7e12e9be4aa 100644
--- a/clippy_lints/src/lib.rs
+++ b/clippy_lints/src/lib.rs
@@ -356,6 +356,7 @@ mod unicode;
mod unit_return_expecting_ord;
mod unit_types;
mod unnamed_address;
+mod unnecessary_self_imports;
mod unnecessary_sort_by;
mod unnecessary_wraps;
mod unnested_or_patterns;
@@ -963,6 +964,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
unit_types::UNIT_CMP,
unnamed_address::FN_ADDRESS_COMPARISONS,
unnamed_address::VTABLE_ADDRESS_COMPARISONS,
+ unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS,
unnecessary_sort_by::UNNECESSARY_SORT_BY,
unnecessary_wraps::UNNECESSARY_WRAPS,
unnested_or_patterns::UNNESTED_OR_PATTERNS,
@@ -1048,6 +1050,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
store.register_late_pass(|| box default_numeric_fallback::DefaultNumericFallback);
store.register_late_pass(|| box inconsistent_struct_constructor::InconsistentStructConstructor);
store.register_late_pass(|| box non_octal_unix_permissions::NonOctalUnixPermissions);
+ store.register_early_pass(|| box unnecessary_self_imports::UnnecessarySelfImports);
let msrv = conf.msrv.as_ref().and_then(|s| {
parse_msrv(s, None, None).or_else(|| {
@@ -1320,6 +1323,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
LintId::of(strings::STRING_TO_STRING),
LintId::of(strings::STR_TO_STRING),
LintId::of(types::RC_BUFFER),
+ LintId::of(unnecessary_self_imports::UNNECESSARY_SELF_IMPORTS),
LintId::of(unwrap_in_result::UNWRAP_IN_RESULT),
LintId::of(verbose_file_reads::VERBOSE_FILE_READS),
LintId::of(write::PRINT_STDERR),
diff --git a/clippy_lints/src/modulo_arithmetic.rs b/clippy_lints/src/modulo_arithmetic.rs
index 6a52de4f713..64e9dc85466 100644
--- a/clippy_lints/src/modulo_arithmetic.rs
+++ b/clippy_lints/src/modulo_arithmetic.rs
@@ -4,7 +4,7 @@ use clippy_utils::sext;
use if_chain::if_chain;
use rustc_hir::{BinOpKind, Expr, ExprKind};
use rustc_lint::{LateContext, LateLintPass};
-use rustc_middle::ty::{self};
+use rustc_middle::ty;
use rustc_session::{declare_lint_pass, declare_tool_lint};
use std::fmt::Display;
diff --git a/clippy_lints/src/unnecessary_self_imports.rs b/clippy_lints/src/unnecessary_self_imports.rs
new file mode 100644
index 00000000000..48c54d79cf1
--- /dev/null
+++ b/clippy_lints/src/unnecessary_self_imports.rs
@@ -0,0 +1,67 @@
+use clippy_utils::diagnostics::span_lint_and_then;
+use if_chain::if_chain;
+use rustc_ast::{Item, ItemKind, UseTreeKind};
+use rustc_errors::Applicability;
+use rustc_lint::{EarlyContext, EarlyLintPass};
+use rustc_session::{declare_lint_pass, declare_tool_lint};
+use rustc_span::symbol::kw;
+
+declare_clippy_lint! {
+ /// **What it does:** Checks for imports ending in `::{self}`.
+ ///
+ /// **Why is this bad?** In most cases, this can be written much more cleanly by omitting `::{self}`.
+ ///
+ /// **Known problems:** Removing `::{self}` will cause any non-module items at the same path to also be imported.
+ /// This might cause a naming conflict (https://github.com/rust-lang/rustfmt/issues/3568). This lint makes no attempt
+ /// to detect this scenario and that is why it is a restriction lint.
+ ///
+ /// **Example:**
+ ///
+ /// ```rust
+ /// use std::io::{self};
+ /// ```
+ /// Use instead:
+ /// ```rust
+ /// use std::io;
+ /// ```
+ pub UNNECESSARY_SELF_IMPORTS,
+ restriction,
+ "imports ending in `::{self}`, which can be omitted"
+}
+
+declare_lint_pass!(UnnecessarySelfImports => [UNNECESSARY_SELF_IMPORTS]);
+
+impl EarlyLintPass for UnnecessarySelfImports {
+ fn check_item(&mut self, cx: &EarlyContext<'_>, item: &Item) {
+ if_chain! {
+ if let ItemKind::Use(use_tree) = &item.kind;
+ if let UseTreeKind::Nested(nodes) = &use_tree.kind;
+ if let [(self_tree, _)] = &**nodes;
+ if let [self_seg] = &*self_tree.prefix.segments;
+ if self_seg.ident.name == kw::SelfLower;
+ if let Some(last_segment) = use_tree.prefix.segments.last();
+
+ then {
+ span_lint_and_then(
+ cx,
+ UNNECESSARY_SELF_IMPORTS,
+ item.span,
+ "import ending with `::{self}`",
+ |diag| {
+ diag.span_suggestion(
+ last_segment.span().with_hi(item.span.hi()),
+ "consider omitting `::{self}`",
+ format!(
+ "{}{};",
+ last_segment.ident,
+ if let UseTreeKind::Simple(Some(alias), ..) = self_tree.kind { format!(" as {}", alias) } else { String::new() },
+ ),
+ Applicability::MaybeIncorrect,
+ );
+ diag.note("this will slightly change semantics; any non-module items at the same path will also be imported");
+ },
+ );
+ }
+ }
+ }
+}
diff --git a/tests/ui/unnecessary_self_imports.fixed b/tests/ui/unnecessary_self_imports.fixed
new file mode 100644
index 00000000000..1185eaa1d55
--- /dev/null
+++ b/tests/ui/unnecessary_self_imports.fixed
@@ -0,0 +1,10 @@
+// run-rustfix
+#![warn(clippy::unnecessary_self_imports)]
+#![allow(unused_imports, dead_code)]
+
+use std::collections::hash_map::{self, *};
+use std::fs as alias;
+use std::io::{self, Read};
+use std::rc;
+
+fn main() {}
diff --git a/tests/ui/unnecessary_self_imports.rs b/tests/ui/unnecessary_self_imports.rs
new file mode 100644
index 00000000000..56bfbc09402
--- /dev/null
+++ b/tests/ui/unnecessary_self_imports.rs
@@ -0,0 +1,10 @@
+// run-rustfix
+#![warn(clippy::unnecessary_self_imports)]
+#![allow(unused_imports, dead_code)]
+
+use std::collections::hash_map::{self, *};
+use std::fs::{self as alias};
+use std::io::{self, Read};
+use std::rc::{self};
+
+fn main() {}
diff --git a/tests/ui/unnecessary_self_imports.stderr b/tests/ui/unnecessary_self_imports.stderr
new file mode 100644
index 00000000000..83a5618c983
--- /dev/null
+++ b/tests/ui/unnecessary_self_imports.stderr
@@ -0,0 +1,23 @@
+error: import ending with `::{self}`
+ --> $DIR/unnecessary_self_imports.rs:6:1
+ |
+LL | use std::fs::{self as alias};
+ | ^^^^^^^^^--------------------
+ | |
+ | help: consider omitting `::{self}`: `fs as alias;`
+ |
+ = note: `-D clippy::unnecessary-self-imports` implied by `-D warnings`
+ = note: this will slightly change semantics; any non-module items at the same path will also be imported
+
+error: import ending with `::{self}`
+ --> $DIR/unnecessary_self_imports.rs:8:1
+ |
+LL | use std::rc::{self};
+ | ^^^^^^^^^-----------
+ | |
+ | help: consider omitting `::{self}`: `rc;`
+ |
+ = note: this will slightly change semantics; any non-module items at the same path will also be imported
+
+error: aborting due to 2 previous errors
+