Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

consider mutability on useless_vec suggestions #7036

Merged
merged 1 commit into from
Apr 6, 2021
Merged

consider mutability on useless_vec suggestions #7036

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
54 changes: 42 additions & 12 deletions clippy_lints/src/vec.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@ use clippy_utils::source::snippet_with_applicability;
use clippy_utils::ty::is_copy;
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir::{BorrowKind, Expr, ExprKind};
use rustc_hir::{BorrowKind, Expr, ExprKind, Mutability};
use rustc_lint::{LateContext, LateLintPass};
use rustc_middle::ty::{self, Ty};
use rustc_session::{declare_tool_lint, impl_lint_pass};
Expand Down Expand Up @@ -49,10 +49,10 @@ impl<'tcx> LateLintPass<'tcx> for UselessVec {
if_chain! {
if let ty::Ref(_, ty, _) = cx.typeck_results().expr_ty_adjusted(expr).kind();
if let ty::Slice(..) = ty.kind();
if let ExprKind::AddrOf(BorrowKind::Ref, _, ref addressee) = expr.kind;
if let ExprKind::AddrOf(BorrowKind::Ref, mutability, ref addressee) = expr.kind;
if let Some(vec_args) = higher::vec_macro(cx, addressee);
then {
self.check_vec_macro(cx, &vec_args, expr.span);
self.check_vec_macro(cx, &vec_args, mutability, expr.span);
}
}

Expand All @@ -70,14 +70,20 @@ impl<'tcx> LateLintPass<'tcx> for UselessVec {
.ctxt()
.outer_expn_data()
.call_site;
self.check_vec_macro(cx, &vec_args, span);
self.check_vec_macro(cx, &vec_args, Mutability::Not, span);
}
}
}
}

impl UselessVec {
fn check_vec_macro<'tcx>(self, cx: &LateContext<'tcx>, vec_args: &higher::VecArgs<'tcx>, span: Span) {
fn check_vec_macro<'tcx>(
self,
cx: &LateContext<'tcx>,
vec_args: &higher::VecArgs<'tcx>,
mutability: Mutability,
span: Span,
) {
let mut applicability = Applicability::MachineApplicable;
let snippet = match *vec_args {
higher::VecArgs::Repeat(elem, len) => {
Expand All @@ -87,11 +93,22 @@ impl UselessVec {
return;
}

format!(
"&[{}; {}]",
snippet_with_applicability(cx, elem.span, "elem", &mut applicability),
snippet_with_applicability(cx, len.span, "len", &mut applicability)
)
match mutability {
Mutability::Mut => {
format!(
"&mut [{}; {}]",
snippet_with_applicability(cx, elem.span, "elem", &mut applicability),
snippet_with_applicability(cx, len.span, "len", &mut applicability)
)
},
Mutability::Not => {
format!(
"&[{}; {}]",
snippet_with_applicability(cx, elem.span, "elem", &mut applicability),
snippet_with_applicability(cx, len.span, "len", &mut applicability)
)
},
}
} else {
return;
}
Expand All @@ -104,9 +121,22 @@ impl UselessVec {
}
let span = args[0].span.to(last.span);

format!("&[{}]", snippet_with_applicability(cx, span, "..", &mut applicability))
match mutability {
Mutability::Mut => {
format!(
"&mut [{}]",
snippet_with_applicability(cx, span, "..", &mut applicability)
)
},
Mutability::Not => {
format!("&[{}]", snippet_with_applicability(cx, span, "..", &mut applicability))
},
}
} else {
"&[]".into()
match mutability {
Mutability::Mut => "&mut []".into(),
Mutability::Not => "&[]".into(),
}
}
},
};
Expand Down
16 changes: 16 additions & 0 deletions tests/ui/vec.fixed
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,9 +6,14 @@
struct NonCopy;

fn on_slice(_: &[u8]) {}

fn on_mut_slice(_: &mut [u8]) {}

#[allow(clippy::ptr_arg)]
fn on_vec(_: &Vec<u8>) {}

fn on_mut_vec(_: &mut Vec<u8>) {}

struct Line {
length: usize,
}
Expand All @@ -22,28 +27,38 @@ impl Line {
fn main() {
on_slice(&[]);
on_slice(&[]);
on_mut_slice(&mut []);

on_slice(&[1, 2]);
on_slice(&[1, 2]);
on_mut_slice(&mut [1, 2]);

on_slice(&[1, 2]);
on_slice(&[1, 2]);
on_mut_slice(&mut [1, 2]);
#[rustfmt::skip]
on_slice(&[1, 2]);
on_slice(&[1, 2]);
on_mut_slice(&mut [1, 2]);

on_slice(&[1; 2]);
on_slice(&[1; 2]);
on_mut_slice(&mut [1; 2]);

on_vec(&vec![]);
on_vec(&vec![1, 2]);
on_vec(&vec![1; 2]);
on_mut_vec(&mut vec![]);
on_mut_vec(&mut vec![1, 2]);
on_mut_vec(&mut vec![1; 2]);

// Now with non-constant expressions
let line = Line { length: 2 };

on_slice(&vec![2; line.length]);
on_slice(&vec![2; line.length()]);
on_mut_slice(&mut vec![2; line.length]);
on_mut_slice(&mut vec![2; line.length()]);

for a in &[1, 2, 3] {
println!("{:?}", a);
Expand All @@ -54,6 +69,7 @@ fn main() {
}

on_vec(&vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack`
on_mut_vec(&mut vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack`

// Ok
for a in vec![1; 201] {
Expand Down
16 changes: 16 additions & 0 deletions tests/ui/vec.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,9 +6,14 @@
struct NonCopy;

fn on_slice(_: &[u8]) {}

fn on_mut_slice(_: &mut [u8]) {}

#[allow(clippy::ptr_arg)]
fn on_vec(_: &Vec<u8>) {}

fn on_mut_vec(_: &mut Vec<u8>) {}

struct Line {
length: usize,
}
Expand All @@ -22,28 +27,38 @@ impl Line {
fn main() {
on_slice(&vec![]);
on_slice(&[]);
on_mut_slice(&mut vec![]);

on_slice(&vec![1, 2]);
on_slice(&[1, 2]);
on_mut_slice(&mut vec![1, 2]);

on_slice(&vec![1, 2]);
on_slice(&[1, 2]);
on_mut_slice(&mut vec![1, 2]);
#[rustfmt::skip]
on_slice(&vec!(1, 2));
on_slice(&[1, 2]);
on_mut_slice(&mut vec![1, 2]);

on_slice(&vec![1; 2]);
on_slice(&[1; 2]);
on_mut_slice(&mut vec![1; 2]);

on_vec(&vec![]);
on_vec(&vec![1, 2]);
on_vec(&vec![1; 2]);
on_mut_vec(&mut vec![]);
on_mut_vec(&mut vec![1, 2]);
on_mut_vec(&mut vec![1; 2]);

// Now with non-constant expressions
let line = Line { length: 2 };

on_slice(&vec![2; line.length]);
on_slice(&vec![2; line.length()]);
on_mut_slice(&mut vec![2; line.length]);
on_mut_slice(&mut vec![2; line.length()]);

for a in vec![1, 2, 3] {
println!("{:?}", a);
Expand All @@ -54,6 +69,7 @@ fn main() {
}

on_vec(&vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack`
on_mut_vec(&mut vec![1; 201]); // Ok, size of `vec` higher than `too_large_for_stack`

// Ok
for a in vec![1; 201] {
Expand Down
44 changes: 37 additions & 7 deletions tests/ui/vec.stderr
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,40 +1,70 @@
error: useless use of `vec!`
--> $DIR/vec.rs:23:14
--> $DIR/vec.rs:28:14
|
LL | on_slice(&vec![]);
| ^^^^^^^ help: you can use a slice directly: `&[]`
|
= note: `-D clippy::useless-vec` implied by `-D warnings`

error: useless use of `vec!`
--> $DIR/vec.rs:26:14
--> $DIR/vec.rs:30:18
|
LL | on_mut_slice(&mut vec![]);
| ^^^^^^^^^^^ help: you can use a slice directly: `&mut []`

error: useless use of `vec!`
--> $DIR/vec.rs:32:14
|
LL | on_slice(&vec![1, 2]);
| ^^^^^^^^^^^ help: you can use a slice directly: `&[1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:29:14
--> $DIR/vec.rs:34:18
|
LL | on_mut_slice(&mut vec![1, 2]);
| ^^^^^^^^^^^^^^^ help: you can use a slice directly: `&mut [1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:36:14
|
LL | on_slice(&vec![1, 2]);
| ^^^^^^^^^^^ help: you can use a slice directly: `&[1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:32:14
--> $DIR/vec.rs:38:18
|
LL | on_mut_slice(&mut vec![1, 2]);
| ^^^^^^^^^^^^^^^ help: you can use a slice directly: `&mut [1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:40:14
|
LL | on_slice(&vec!(1, 2));
| ^^^^^^^^^^^ help: you can use a slice directly: `&[1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:35:14
--> $DIR/vec.rs:42:18
|
LL | on_mut_slice(&mut vec![1, 2]);
| ^^^^^^^^^^^^^^^ help: you can use a slice directly: `&mut [1, 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:44:14
|
LL | on_slice(&vec![1; 2]);
| ^^^^^^^^^^^ help: you can use a slice directly: `&[1; 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:48:14
--> $DIR/vec.rs:46:18
|
LL | on_mut_slice(&mut vec![1; 2]);
| ^^^^^^^^^^^^^^^ help: you can use a slice directly: `&mut [1; 2]`

error: useless use of `vec!`
--> $DIR/vec.rs:63:14
|
LL | for a in vec![1, 2, 3] {
| ^^^^^^^^^^^^^ help: you can use a slice directly: `&[1, 2, 3]`

error: aborting due to 6 previous errors
error: aborting due to 11 previous errors