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Auto merge of #4454 - BO41:search_is_some, r=flip1995

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Dereference one less on search_is_some and make it auto-fixable

Fixes #4453

changelog: none
This commit is contained in:
bors 2019-09-04 07:53:44 +00:00
commit 8239b7616f
6 changed files with 94 additions and 59 deletions
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84
clippy_lints/src/methods/mod.rs
View File

@ -1033,7 +1033,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
return;
}
let (method_names, arg_lists) = method_calls(expr, 2);
let (method_names, arg_lists, method_spans) = method_calls(expr, 2);
let method_names: Vec<LocalInternedString> = method_names.iter().map(|s| s.as_str()).collect();
let method_names: Vec<&str> = method_names.iter().map(std::convert::AsRef::as_ref).collect();
@ -1053,11 +1053,15 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
["map", "find"] => lint_find_map(cx, expr, arg_lists[1], arg_lists[0]),
["flat_map", "filter"] => lint_filter_flat_map(cx, expr, arg_lists[1], arg_lists[0]),
["flat_map", "filter_map"] => lint_filter_map_flat_map(cx, expr, arg_lists[1], arg_lists[0]),
["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0]),
["flat_map", ..] => lint_flat_map_identity(cx, expr, arg_lists[0], method_spans[0]),
["flatten", "map"] => lint_map_flatten(cx, expr, arg_lists[1]),
["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0]),
["is_some", "position"] => lint_search_is_some(cx, expr, "position", arg_lists[1], arg_lists[0]),
["is_some", "rposition"] => lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0]),
["is_some", "find"] => lint_search_is_some(cx, expr, "find", arg_lists[1], arg_lists[0], method_spans[1]),
["is_some", "position"] => {
lint_search_is_some(cx, expr, "position", arg_lists[1], arg_lists[0], method_spans[1])
},
["is_some", "rposition"] => {
lint_search_is_some(cx, expr, "rposition", arg_lists[1], arg_lists[0], method_spans[1])
},
["extend", ..] => lint_extend(cx, expr, arg_lists[0]),
["as_ptr", "unwrap"] | ["as_ptr", "expect"] => {
lint_cstring_as_ptr(cx, expr, &arg_lists[1][0], &arg_lists[0][0])
@ -1068,7 +1072,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
["collect", "cloned"] => lint_iter_cloned_collect(cx, expr, arg_lists[1]),
["as_ref"] => lint_asref(cx, expr, "as_ref", arg_lists[0]),
["as_mut"] => lint_asref(cx, expr, "as_mut", arg_lists[0]),
["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0]),
["fold", ..] => lint_unnecessary_fold(cx, expr, arg_lists[0], method_spans[0]),
["filter_map", ..] => unnecessary_filter_map::lint(cx, expr, arg_lists[0]),
["count", "map"] => lint_suspicious_map(cx, expr),
["assume_init"] => lint_maybe_uninit(cx, &arg_lists[0][0], expr),
@ -1746,11 +1750,12 @@ fn lint_iter_cloned_collect<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, expr: &hir::Ex
}
}
fn lint_unnecessary_fold(cx: &LateContext<'_, '_>, expr: &hir::Expr, fold_args: &[hir::Expr]) {
fn lint_unnecessary_fold(cx: &LateContext<'_, '_>, expr: &hir::Expr, fold_args: &[hir::Expr], fold_span: Span) {
fn check_fold_with_op(
cx: &LateContext<'_, '_>,
expr: &hir::Expr,
fold_args: &[hir::Expr],
fold_span: Span,
op: hir::BinOpKind,
replacement_method_name: &str,
replacement_has_args: bool,
@ -1772,8 +1777,6 @@ fn check_fold_with_op(
if match_var(&*left_expr, first_arg_ident);
if replacement_has_args || match_var(&*right_expr, second_arg_ident);
if let hir::ExprKind::MethodCall(_, span, _) = &expr.node;
then {
let mut applicability = Applicability::MachineApplicable;
let sugg = if replacement_has_args {
@ -1793,7 +1796,7 @@ fn check_fold_with_op(
span_lint_and_sugg(
cx,
UNNECESSARY_FOLD,
span.with_hi(expr.span.hi()),
fold_span.with_hi(expr.span.hi()),
// TODO #2371 don't suggest e.g., .any(|x| f(x)) if we can suggest .any(f)
"this `.fold` can be written more succinctly using another method",
"try",
@ -1817,10 +1820,18 @@ fn check_fold_with_op(
// Check if the first argument to .fold is a suitable literal
if let hir::ExprKind::Lit(ref lit) = fold_args[1].node {
match lit.node {
ast::LitKind::Bool(false) => check_fold_with_op(cx, expr, fold_args, hir::BinOpKind::Or, "any", true),
ast::LitKind::Bool(true) => check_fold_with_op(cx, expr, fold_args, hir::BinOpKind::And, "all", true),
ast::LitKind::Int(0, _) => check_fold_with_op(cx, expr, fold_args, hir::BinOpKind::Add, "sum", false),
ast::LitKind::Int(1, _) => check_fold_with_op(cx, expr, fold_args, hir::BinOpKind::Mul, "product", false),
ast::LitKind::Bool(false) => {
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Or, "any", true)
},
ast::LitKind::Bool(true) => {
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::And, "all", true)
},
ast::LitKind::Int(0, _) => {
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Add, "sum", false)
},
ast::LitKind::Int(1, _) => {
check_fold_with_op(cx, expr, fold_args, fold_span, hir::BinOpKind::Mul, "product", false)
},
_ => (),
}
}
@ -2357,22 +2368,21 @@ fn lint_flat_map_identity<'a, 'tcx>(
cx: &LateContext<'a, 'tcx>,
expr: &'tcx hir::Expr,
flat_map_args: &'tcx [hir::Expr],
flat_map_span: Span,
) {
if match_trait_method(cx, expr, &paths::ITERATOR) {
let arg_node = &flat_map_args[1].node;
let apply_lint = |message: &str| {
if let hir::ExprKind::MethodCall(_, span, _) = &expr.node {
span_lint_and_sugg(
cx,
FLAT_MAP_IDENTITY,
span.with_hi(expr.span.hi()),
message,
"try",
"flatten()".to_string(),
Applicability::MachineApplicable,
);
}
span_lint_and_sugg(
cx,
FLAT_MAP_IDENTITY,
flat_map_span.with_hi(expr.span.hi()),
message,
"try",
"flatten()".to_string(),
Applicability::MachineApplicable,
);
};
if_chain! {
@ -2409,6 +2419,7 @@ fn lint_search_is_some<'a, 'tcx>(
search_method: &str,
search_args: &'tcx [hir::Expr],
is_some_args: &'tcx [hir::Expr],
method_span: Span,
) {
// lint if caller of search is an Iterator
if match_trait_method(cx, &is_some_args[0], &paths::ITERATOR) {
@ -2420,31 +2431,36 @@ fn lint_search_is_some<'a, 'tcx>(
let search_snippet = snippet(cx, search_args[1].span, "..");
if search_snippet.lines().count() <= 1 {
// suggest `any(|x| ..)` instead of `any(|&x| ..)` for `find(|&x| ..).is_some()`
// suggest `any(|..| *..)` instead of `any(|..| **..)` for `find(|..| **..).is_some()`
let any_search_snippet = if_chain! {
if search_method == "find";
if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].node;
let closure_body = cx.tcx.hir().body(body_id);
if let Some(closure_arg) = closure_body.params.get(0);
if let hir::PatKind::Ref(..) = closure_arg.pat.node;
then {
Some(search_snippet.replacen('&', "", 1))
if let hir::PatKind::Ref(..) = closure_arg.pat.node {
Some(search_snippet.replacen('&', "", 1))
} else if let Some(name) = get_arg_name(&closure_arg.pat) {
Some(search_snippet.replace(&format!("*{}", name), &name.as_str()))
} else {
None
}
} else {
None
}
};
// add note if not multi-line
span_note_and_lint(
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
expr.span,
method_span.with_hi(expr.span.hi()),
&msg,
expr.span,
&format!(
"replace `{0}({1}).is_some()` with `any({2})`",
search_method,
search_snippet,
"try this",
format!(
"any({})",
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
Applicability::MachineApplicable,
);
} else {
span_lint(cx, SEARCH_IS_SOME, expr.span, &msg);

6
clippy_lints/src/utils/internal_lints.rs
View File

@ -280,7 +280,7 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx Expr) {
impl<'a, 'tcx> LateLintPass<'a, 'tcx> for OuterExpnDataPass {
fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
let (method_names, arg_lists) = method_calls(expr, 2);
let (method_names, arg_lists, spans) = method_calls(expr, 2);
let method_names: Vec<LocalInternedString> = method_names.iter().map(|s| s.as_str()).collect();
let method_names: Vec<&str> = method_names.iter().map(std::convert::AsRef::as_ref).collect();
if_chain! {
@ -294,10 +294,10 @@ fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
span_lint_and_sugg(
cx,
OUTER_EXPN_EXPN_DATA,
expr.span.trim_start(self_arg.span).unwrap_or(expr.span),
spans[1].with_hi(expr.span.hi()),
"usage of `outer_expn().expn_data()`",
"try",
".outer_expn_data()".to_string(),
"outer_expn_data()".to_string(),
Applicability::MachineApplicable,
);
}

10
clippy_lints/src/utils/mod.rs
View File

@ -342,26 +342,28 @@ pub fn resolve_node(cx: &LateContext<'_, '_>, qpath: &QPath, id: HirId) -> Res {
}
/// Returns the method names and argument list of nested method call expressions that make up
/// `expr`.
pub fn method_calls(expr: &Expr, max_depth: usize) -> (Vec<Symbol>, Vec<&[Expr]>) {
/// `expr`. method/span lists are sorted with the most recent call first.
pub fn method_calls(expr: &Expr, max_depth: usize) -> (Vec<Symbol>, Vec<&[Expr]>, Vec<Span>) {
let mut method_names = Vec::with_capacity(max_depth);
let mut arg_lists = Vec::with_capacity(max_depth);
let mut spans = Vec::with_capacity(max_depth);
let mut current = expr;
for _ in 0..max_depth {
if let ExprKind::MethodCall(path, _, args) = &current.node {
if let ExprKind::MethodCall(path, span, args) = &current.node {
if args.iter().any(|e| e.span.from_expansion()) {
break;
}
method_names.push(path.ident.name);
arg_lists.push(&**args);
spans.push(*span);
current = &args[0];
} else {
break;
}
}
(method_names, arg_lists)
(method_names, arg_lists, spans)
}
/// Matches an `Expr` against a chain of methods, and return the matched `Expr`s.

4
tests/ui/methods.rs
View File

@ -260,9 +260,13 @@ fn filter_next() {
#[rustfmt::skip]
fn search_is_some() {
let v = vec![3, 2, 1, 0, -1, -2, -3];
let y = &&42;
// Check `find().is_some()`, single-line case.
let _ = v.iter().find(|&x| *x < 0).is_some();
let _ = (0..1).find(|x| **y == *x).is_some(); // one dereference less
let _ = (0..1).find(|x| *x == 0).is_some();
let _ = v.iter().find(|x| **x == 0).is_some();
// Check `find().is_some()`, multi-line case.
let _ = v.iter().find(|&x| {

45
tests/ui/methods.stderr
View File

@ -139,16 +139,33 @@ LL | | ).next();
| |___________________________^
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:265:13
--> $DIR/methods.rs:266:22
|
LL | let _ = v.iter().find(|&x| *x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| *x < 0)`
|
= note: `-D clippy::search-is-some` implied by `-D warnings`
= note: replace `find(|&x| *x < 0).is_some()` with `any(|x| *x < 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:268:13
--> $DIR/methods.rs:267:20
|
LL | let _ = (0..1).find(|x| **y == *x).is_some(); // one dereference less
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| **y == x)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:268:20
|
LL | let _ = (0..1).find(|x| *x == 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| x == 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:269:22
|
LL | let _ = v.iter().find(|x| **x == 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|x| *x == 0)`
error: called `is_some()` after searching an `Iterator` with find. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:272:13
|
LL | let _ = v.iter().find(|&x| {
| _____________^
@ -158,15 +175,13 @@ LL | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:274:13
--> $DIR/methods.rs:278:22
|
LL | let _ = v.iter().position(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `position(|&x| x < 0).is_some()` with `any(|&x| x < 0)`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with position. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:277:13
--> $DIR/methods.rs:281:13
|
LL | let _ = v.iter().position(|&x| {
| _____________^
@ -176,15 +191,13 @@ LL | | ).is_some();
| |______________________________^
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:283:13
--> $DIR/methods.rs:287:22
|
LL | let _ = v.iter().rposition(|&x| x < 0).is_some();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: replace `rposition(|&x| x < 0).is_some()` with `any(|&x| x < 0)`
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `any(|&x| x < 0)`
error: called `is_some()` after searching an `Iterator` with rposition. This is more succinctly expressed by calling `any()`.
--> $DIR/methods.rs:286:13
--> $DIR/methods.rs:290:13
|
LL | let _ = v.iter().rposition(|&x| {
| _____________^
@ -194,12 +207,12 @@ LL | | ).is_some();
| |______________________________^
error: used unwrap() on an Option value. If you don't want to handle the None case gracefully, consider using expect() to provide a better panic message
--> $DIR/methods.rs:301:13
--> $DIR/methods.rs:305:13
|
LL | let _ = opt.unwrap();
| ^^^^^^^^^^^^
|
= note: `-D clippy::option-unwrap-used` implied by `-D warnings`
error: aborting due to 21 previous errors
error: aborting due to 24 previous errors

4
tests/ui/outer_expn_data.stderr
View File

@ -1,8 +1,8 @@
error: usage of `outer_expn().expn_data()`
--> $DIR/outer_expn_data.rs:21:33
--> $DIR/outer_expn_data.rs:21:34
|
LL | let _ = expr.span.ctxt().outer_expn().expn_data();
| ^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `.outer_expn_data()`
| ^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `outer_expn_data()`
|
note: lint level defined here
--> $DIR/outer_expn_data.rs:3:9