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Use ExprUseVisitor and multipart suggestion to avoid iffy String …
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…replacement
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@ThibsG
ThibsG committed Nov 20, 2021
1 parent f4c75cd commit 5ed93af
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Showing 6 changed files with 334 additions and 209 deletions.
186 changes: 140 additions & 46 deletions clippy_lints/src/methods/search_is_some.rs
View file
@@ -1,15 +1,19 @@
use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg, span_lint_and_then};
use clippy_utils::source::{snippet, snippet_with_applicability};
use clippy_utils::ty::is_type_diagnostic_item;
use clippy_utils::{is_trait_method, strip_pat_refs};
use if_chain::if_chain;
use rustc_errors::Applicability;
use rustc_hir as hir;
use rustc_hir::PatKind;
use rustc_hir::{self, HirId, HirIdMap, HirIdSet, PatKind};
use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
use rustc_middle::hir::place::ProjectionKind;
use rustc_middle::mir::FakeReadCause;
use rustc_middle::ty;
use rustc_span::source_map::Span;
use rustc_span::symbol::sym;
use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};

use super::SEARCH_IS_SOME;

Expand Down Expand Up @@ -42,30 +46,42 @@ pub(super) fn check<'tcx>(
if let hir::ExprKind::Closure(_, _, body_id, ..) = search_arg.kind;
let closure_body = cx.tcx.hir().body(body_id);
if let Some(closure_arg) = closure_body.params.get(0);

then {
if let hir::PatKind::Ref(..) = closure_arg.pat.kind {
Some(search_snippet.replacen('&', "", 1))
} else if let PatKind::Binding(annotation, _, ident, _) = strip_pat_refs(closure_arg.pat).kind {
let name = &*ident.name.as_str();
let old_search_snippet = search_snippet.clone();
let search_snippet = search_snippet.replace(&format!("*{}", name), name);

if_chain! {
// if there is no dereferencing used in closure body
if old_search_snippet == search_snippet;
if annotation == hir::BindingAnnotation::Unannotated;
if let ty::Ref(_, inner_ty, _) = cx.typeck_results().node_type(closure_arg.hir_id).kind();
if let ty::Ref(..) = inner_ty.kind();
// put an `&` in the closure body, but skip closure params
if let Some((start, end)) = old_search_snippet.split_once(&name);

then {
let end = end.replace(name, &format!("&{}", name));
Some(format!("{}{}{}", start, name, end))
} else {
Some(search_snippet)
Some((search_snippet.replacen('&', "", 1), None))
} else if let PatKind::Binding(..) = strip_pat_refs(closure_arg.pat).kind {
let mut visitor = DerefDelegate {
cx,
set: HirIdSet::default(),
deref_suggs: HirIdMap::default(),
borrow_suggs: HirIdMap::default()
};

let fn_def_id = cx.tcx.hir().local_def_id(search_arg.hir_id);
cx.tcx.infer_ctxt().enter(|infcx| {
ExprUseVisitor::new(
&mut visitor, &infcx, fn_def_id, cx.param_env, cx.typeck_results()
).consume_body(closure_body);
});

let replacements = if visitor.set.is_empty() {
None
} else {
let mut deref_suggs = Vec::new();
let mut borrow_suggs = Vec::new();
for node in visitor.set {
let span = cx.tcx.hir().span(node);
if let Some(sugg) = visitor.deref_suggs.get(&node) {
deref_suggs.push((span, sugg.clone()));
}
if let Some(sugg) = visitor.borrow_suggs.get(&node) {
borrow_suggs.push((span, sugg.clone()));
}
}
}
Some((deref_suggs, borrow_suggs))
};
Some((search_snippet.to_string(), replacements))
} else {
None
}
Expand All @@ -74,35 +90,38 @@ pub(super) fn check<'tcx>(
}
};
// add note if not multi-line
if is_some {
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
let (closure_snippet, replacements) = any_search_snippet
.as_ref()
.map_or((&*search_snippet, None), |s| (&s.0, s.1.clone()));
let (span, help, sugg) = if is_some {
(
method_span.with_hi(expr.span.hi()),
&msg,
"use `any()` instead",
format!(
"any({})",
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
Applicability::MachineApplicable,
);
format!("any({})", closure_snippet),
)
} else {
let iter = snippet(cx, search_recv.span, "..");
span_lint_and_sugg(
cx,
SEARCH_IS_SOME,
(
expr.span,
&msg,
"use `!_.any()` instead",
format!(
"!{}.any({})",
iter,
any_search_snippet.as_ref().map_or(&*search_snippet, String::as_str)
),
Applicability::MachineApplicable,
);
}
format!("!{}.any({})", iter, closure_snippet),
)
};

span_lint_and_then(cx, SEARCH_IS_SOME, span, &msg, |db| {
if let Some((deref_suggs, borrow_suggs)) = replacements {
db.span_suggestion(span, help, sugg, Applicability::MaybeIncorrect);

if !deref_suggs.is_empty() {
db.multipart_suggestion("...and remove deref", deref_suggs, Applicability::MaybeIncorrect);
}
if !borrow_suggs.is_empty() {
db.multipart_suggestion("...and borrow variable", borrow_suggs, Applicability::MaybeIncorrect);
}
} else {
db.span_suggestion(span, help, sugg, Applicability::MachineApplicable);
}
});
} else {
let hint = format!(
"this is more succinctly expressed by calling `any()`{}",
Expand Down Expand Up @@ -164,3 +183,78 @@ pub(super) fn check<'tcx>(
}
}
}

struct DerefDelegate<'a, 'tcx> {
cx: &'a LateContext<'tcx>,
set: HirIdSet,
deref_suggs: HirIdMap<String>,
borrow_suggs: HirIdMap<String>,
}

impl<'tcx> Delegate<'tcx> for DerefDelegate<'_, 'tcx> {
fn consume(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId) {
if let PlaceBase::Local(id) = cmt.place.base {
let map = self.cx.tcx.hir();
if cmt.place.projections.is_empty() {
self.set.insert(cmt.hir_id);
} else {
let mut replacement_str = map.name(id).to_string();
let last_deref = cmt
.place
.projections
.iter()
.rposition(|proj| proj.kind == ProjectionKind::Deref);

if let Some(pos) = last_deref {
let mut projections = cmt.place.projections.clone();
projections.truncate(pos);

for item in projections {
if item.kind == ProjectionKind::Deref {
replacement_str = format!("*{}", replacement_str);
}
}

self.set.insert(cmt.hir_id);
self.deref_suggs.insert(cmt.hir_id, replacement_str);
}
}
}
}

fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId, _: ty::BorrowKind) {
if let PlaceBase::Local(id) = cmt.place.base {
let map = self.cx.tcx.hir();
if cmt.place.projections.is_empty() {
let replacement_str = format!("&{}", map.name(id).to_string());
self.set.insert(cmt.hir_id);
self.borrow_suggs.insert(cmt.hir_id, replacement_str);
} else {
let mut replacement_str = map.name(id).to_string();
let last_deref = cmt
.place
.projections
.iter()
.rposition(|proj| proj.kind == ProjectionKind::Deref);

if let Some(pos) = last_deref {
let mut projections = cmt.place.projections.clone();
projections.truncate(pos);

for item in projections {
if item.kind == ProjectionKind::Deref {
replacement_str = format!("*{}", replacement_str);
}
}

self.set.insert(cmt.hir_id);
self.deref_suggs.insert(cmt.hir_id, replacement_str);
}
}
}
}

fn mutate(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {}

fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
}
45 changes: 45 additions & 0 deletions tests/ui/search_is_some.rs
View file
Expand Up @@ -36,6 +36,11 @@ fn main() {
// check that we don't lint if `find()` is called with
// `Pattern` that is not a string
let _ = "hello world".find(|c: char| c == 'o' || c == 'l').is_some();

// Check `find().is_some()`, single-line case.
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();
}

#[rustfmt::skip]
Expand Down Expand Up @@ -70,4 +75,44 @@ fn is_none() {
// check that we don't lint if `find()` is called with
// `Pattern` that is not a string
let _ = "hello world".find(|c: char| c == 'o' || c == 'l').is_none();

// Check `find().is_none()`, single-line case.
let _ = (0..1).find(|x| **y == *x).is_none(); // one dereference less
let _ = (0..1).find(|x| *x == 0).is_none();
let _ = v.iter().find(|x| **x == 0).is_none();
}

#[allow(clippy::clone_on_copy, clippy::map_clone)]
mod issue7392 {
struct Player {
hand: Vec<usize>,
}
fn filter() {
let p = Player {
hand: vec![1, 2, 3, 4, 5],
};
let filter_hand = vec![5];
let _ = p
.hand
.iter()
.filter(|c| filter_hand.iter().find(|cc| c == cc).is_none())
.map(|c| c.clone())
.collect::<Vec<_>>();
}

struct PlayerTuple {
hand: Vec<(usize, char)>,
}
fn filter_tuple() {
let p = PlayerTuple {
hand: vec![(1, 'a'), (2, 'b'), (3, 'c'), (4, 'd'), (5, 'e')],
};
let filter_hand = vec![5];
let _ = p
.hand
.iter()
.filter(|(c, _)| filter_hand.iter().find(|cc| c == *cc).is_none())
.map(|c| c.clone())
.collect::<Vec<_>>();
}
}

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