use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::source::{snippet, snippet_with_macro_callsite};
use clippy_utils::sugg::Sugg;
-use clippy_utils::ty::{is_type_diagnostic_item, same_type_and_consts};
-use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, paths};
+use clippy_utils::ty::{is_copy, is_type_diagnostic_item, same_type_and_consts};
+use clippy_utils::{get_parent_expr, is_trait_method, match_def_path, path_to_local, paths};
use if_chain::if_chain;
use rustc_errors::Applicability;
-use rustc_hir::{Expr, ExprKind, HirId, MatchSource};
+use rustc_hir::{BindingAnnotation, Expr, ExprKind, HirId, MatchSource, Node, PatKind};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty;
use rustc_session::{declare_tool_lint, impl_lint_pass};
}
}
if is_trait_method(cx, e, sym::IntoIterator) && name.ident.name == sym::into_iter {
- if let Some(parent_expr) = get_parent_expr(cx, e) {
- if let ExprKind::MethodCall(parent_name, ..) = parent_expr.kind {
- if parent_name.ident.name != sym::into_iter {
- return;
- }
- }
+ if get_parent_expr(cx, e).is_some() &&
+ let Some(id) = path_to_local(recv) &&
+ let Node::Pat(pat) = cx.tcx.hir().get(id) &&
+ let PatKind::Binding(ann, ..) = pat.kind &&
+ ann != BindingAnnotation::MUT
+ {
+ // Do not remove .into_iter() applied to a non-mutable local variable used in
+ // a larger expression context as it would differ in mutability.
+ return;
}
+
let a = cx.typeck_results().expr_ty(e);
let b = cx.typeck_results().expr_ty(recv);
- if same_type_and_consts(a, b) {
+
+ // If the types are identical then .into_iter() can be removed, unless the type
+ // implements Copy, in which case .into_iter() returns a copy of the receiver and
+ // cannot be safely omitted.
+ if same_type_and_consts(a, b) && !is_copy(cx, b) {
let sugg = snippet(cx, recv.span, "<expr>").into_owned();
span_lint_and_sugg(
cx,
Ok(())
}
-fn test_issue_5833() -> Result<(), ()> {
+fn dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr() {
let text = "foo\r\nbar\n\nbaz\n";
let lines = text.lines();
if Some("ok") == lines.into_iter().next() {}
+}
- Ok(())
+fn lint_into_iter_on_mutable_local_implementing_iterator_in_expr() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ let mut lines = text.lines();
+ if Some("ok") == lines.next() {}
+}
+
+fn lint_into_iter_on_expr_implementing_iterator() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ let mut lines = text.lines();
+ if Some("ok") == lines.next() {}
+}
+
+fn lint_into_iter_on_expr_implementing_iterator_2() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ if Some("ok") == text.lines().next() {}
+}
+
+#[allow(const_item_mutation)]
+fn lint_into_iter_on_const_implementing_iterator() {
+ const NUMBERS: std::ops::Range<i32> = 0..10;
+ let _ = NUMBERS.next();
+}
+
+fn lint_into_iter_on_const_implementing_iterator_2() {
+ const NUMBERS: std::ops::Range<i32> = 0..10;
+ let mut n = NUMBERS;
+ n.next();
+}
+
+#[derive(Clone, Copy)]
+struct CopiableCounter {
+ counter: u32,
+}
+
+impl Iterator for CopiableCounter {
+ type Item = u32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ self.counter = self.counter.wrapping_add(1);
+ Some(self.counter)
+ }
+}
+
+fn dont_lint_into_iter_on_copy_iter() {
+ let mut c = CopiableCounter { counter: 0 };
+ assert_eq!(c.into_iter().next(), Some(1));
+ assert_eq!(c.into_iter().next(), Some(1));
+ assert_eq!(c.next(), Some(1));
+ assert_eq!(c.next(), Some(2));
+}
+
+fn dont_lint_into_iter_on_static_copy_iter() {
+ static mut C: CopiableCounter = CopiableCounter { counter: 0 };
+ unsafe {
+ assert_eq!(C.into_iter().next(), Some(1));
+ assert_eq!(C.into_iter().next(), Some(1));
+ assert_eq!(C.next(), Some(1));
+ assert_eq!(C.next(), Some(2));
+ }
}
fn main() {
test_generic2::<i32, i32>(10i32);
test_questionmark().unwrap();
test_issue_3913().unwrap();
- test_issue_5833().unwrap();
+
+ dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr();
+ lint_into_iter_on_mutable_local_implementing_iterator_in_expr();
+ lint_into_iter_on_expr_implementing_iterator();
+ lint_into_iter_on_expr_implementing_iterator_2();
+ lint_into_iter_on_const_implementing_iterator();
+ lint_into_iter_on_const_implementing_iterator_2();
+ dont_lint_into_iter_on_copy_iter();
+ dont_lint_into_iter_on_static_copy_iter();
let _: String = "foo".into();
let _: String = From::from("foo");
Ok(())
}
-fn test_issue_5833() -> Result<(), ()> {
+fn dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr() {
let text = "foo\r\nbar\n\nbaz\n";
let lines = text.lines();
if Some("ok") == lines.into_iter().next() {}
+}
- Ok(())
+fn lint_into_iter_on_mutable_local_implementing_iterator_in_expr() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ let mut lines = text.lines();
+ if Some("ok") == lines.into_iter().next() {}
+}
+
+fn lint_into_iter_on_expr_implementing_iterator() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ let mut lines = text.lines().into_iter();
+ if Some("ok") == lines.next() {}
+}
+
+fn lint_into_iter_on_expr_implementing_iterator_2() {
+ let text = "foo\r\nbar\n\nbaz\n";
+ if Some("ok") == text.lines().into_iter().next() {}
+}
+
+#[allow(const_item_mutation)]
+fn lint_into_iter_on_const_implementing_iterator() {
+ const NUMBERS: std::ops::Range<i32> = 0..10;
+ let _ = NUMBERS.into_iter().next();
+}
+
+fn lint_into_iter_on_const_implementing_iterator_2() {
+ const NUMBERS: std::ops::Range<i32> = 0..10;
+ let mut n = NUMBERS.into_iter();
+ n.next();
+}
+
+#[derive(Clone, Copy)]
+struct CopiableCounter {
+ counter: u32,
+}
+
+impl Iterator for CopiableCounter {
+ type Item = u32;
+
+ fn next(&mut self) -> Option<Self::Item> {
+ self.counter = self.counter.wrapping_add(1);
+ Some(self.counter)
+ }
+}
+
+fn dont_lint_into_iter_on_copy_iter() {
+ let mut c = CopiableCounter { counter: 0 };
+ assert_eq!(c.into_iter().next(), Some(1));
+ assert_eq!(c.into_iter().next(), Some(1));
+ assert_eq!(c.next(), Some(1));
+ assert_eq!(c.next(), Some(2));
+}
+
+fn dont_lint_into_iter_on_static_copy_iter() {
+ static mut C: CopiableCounter = CopiableCounter { counter: 0 };
+ unsafe {
+ assert_eq!(C.into_iter().next(), Some(1));
+ assert_eq!(C.into_iter().next(), Some(1));
+ assert_eq!(C.next(), Some(1));
+ assert_eq!(C.next(), Some(2));
+ }
}
fn main() {
test_generic2::<i32, i32>(10i32);
test_questionmark().unwrap();
test_issue_3913().unwrap();
- test_issue_5833().unwrap();
+
+ dont_lint_into_iter_on_immutable_local_implementing_iterator_in_expr();
+ lint_into_iter_on_mutable_local_implementing_iterator_in_expr();
+ lint_into_iter_on_expr_implementing_iterator();
+ lint_into_iter_on_expr_implementing_iterator_2();
+ lint_into_iter_on_const_implementing_iterator();
+ lint_into_iter_on_const_implementing_iterator_2();
+ dont_lint_into_iter_on_copy_iter();
+ dont_lint_into_iter_on_static_copy_iter();
let _: String = "foo".into();
let _: String = From::from("foo");
LL | let _: i32 = 0i32.into();
| ^^^^^^^^^^^ help: consider removing `.into()`: `0i32`
+error: useless conversion to the same type: `std::str::Lines<'_>`
+ --> $DIR/useless_conversion.rs:45:22
+ |
+LL | if Some("ok") == lines.into_iter().next() {}
+ | ^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `lines`
+
+error: useless conversion to the same type: `std::str::Lines<'_>`
+ --> $DIR/useless_conversion.rs:50:21
+ |
+LL | let mut lines = text.lines().into_iter();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `text.lines()`
+
+error: useless conversion to the same type: `std::str::Lines<'_>`
+ --> $DIR/useless_conversion.rs:56:22
+ |
+LL | if Some("ok") == text.lines().into_iter().next() {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `text.lines()`
+
+error: useless conversion to the same type: `std::ops::Range<i32>`
+ --> $DIR/useless_conversion.rs:62:13
+ |
+LL | let _ = NUMBERS.into_iter().next();
+ | ^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `NUMBERS`
+
+error: useless conversion to the same type: `std::ops::Range<i32>`
+ --> $DIR/useless_conversion.rs:67:17
+ |
+LL | let mut n = NUMBERS.into_iter();
+ | ^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `NUMBERS`
+
error: useless conversion to the same type: `std::string::String`
- --> $DIR/useless_conversion.rs:61:21
+ --> $DIR/useless_conversion.rs:128:21
|
LL | let _: String = "foo".to_string().into();
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into()`: `"foo".to_string()`
error: useless conversion to the same type: `std::string::String`
- --> $DIR/useless_conversion.rs:62:21
+ --> $DIR/useless_conversion.rs:129:21
|
LL | let _: String = From::from("foo".to_string());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `From::from()`: `"foo".to_string()`
error: useless conversion to the same type: `std::string::String`
- --> $DIR/useless_conversion.rs:63:13
+ --> $DIR/useless_conversion.rs:130:13
|
LL | let _ = String::from("foo".to_string());
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `String::from()`: `"foo".to_string()`
error: useless conversion to the same type: `std::string::String`
- --> $DIR/useless_conversion.rs:64:13
+ --> $DIR/useless_conversion.rs:131:13
|
LL | let _ = String::from(format!("A: {:04}", 123));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `String::from()`: `format!("A: {:04}", 123)`
error: useless conversion to the same type: `std::str::Lines<'_>`
- --> $DIR/useless_conversion.rs:65:13
+ --> $DIR/useless_conversion.rs:132:13
|
LL | let _ = "".lines().into_iter();
| ^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `"".lines()`
error: useless conversion to the same type: `std::vec::IntoIter<i32>`
- --> $DIR/useless_conversion.rs:66:13
+ --> $DIR/useless_conversion.rs:133:13
|
LL | let _ = vec![1, 2, 3].into_iter().into_iter();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![1, 2, 3].into_iter()`
error: useless conversion to the same type: `std::string::String`
- --> $DIR/useless_conversion.rs:67:21
+ --> $DIR/useless_conversion.rs:134:21
|
LL | let _: String = format!("Hello {}", "world").into();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into()`: `format!("Hello {}", "world")`
error: useless conversion to the same type: `i32`
- --> $DIR/useless_conversion.rs:72:13
+ --> $DIR/useless_conversion.rs:139:13
|
LL | let _ = i32::from(a + b) * 3;
| ^^^^^^^^^^^^^^^^ help: consider removing `i32::from()`: `(a + b)`
error: useless conversion to the same type: `Foo<'a'>`
- --> $DIR/useless_conversion.rs:78:23
+ --> $DIR/useless_conversion.rs:145:23
|
LL | let _: Foo<'a'> = s2.into();
| ^^^^^^^^^ help: consider removing `.into()`: `s2`
error: useless conversion to the same type: `Foo<'a'>`
- --> $DIR/useless_conversion.rs:80:13
+ --> $DIR/useless_conversion.rs:147:13
|
LL | let _ = Foo::<'a'>::from(s3);
| ^^^^^^^^^^^^^^^^^^^^ help: consider removing `Foo::<'a'>::from()`: `s3`
error: useless conversion to the same type: `std::vec::IntoIter<Foo<'a'>>`
- --> $DIR/useless_conversion.rs:82:13
+ --> $DIR/useless_conversion.rs:149:13
|
LL | let _ = vec![s4, s4, s4].into_iter().into_iter();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider removing `.into_iter()`: `vec![s4, s4, s4].into_iter()`
-error: aborting due to 14 previous errors
+error: aborting due to 19 previous errors
projects / rust.git / commitdiff