-use crate::utils::{
- is_trait_method, is_type_diagnostic_item, snippet, snippet_with_applicability, span_lint_and_help,
- span_lint_and_sugg, strip_pat_refs,
-};
+use clippy_utils::diagnostics::{span_lint_and_help, span_lint_and_sugg};
+use clippy_utils::source::{snippet, snippet_with_applicability};
+use clippy_utils::ty::is_type_diagnostic_item;
+use clippy_utils::{get_parent_expr_for_hir, 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, ExprKind, HirId, PatKind};
+use rustc_infer::infer::TyCtxtInferExt;
use rustc_lint::LateContext;
+use rustc_middle::hir::place::ProjectionKind;
+use rustc_middle::mir::{FakeReadCause, Mutability};
use rustc_middle::ty;
-use rustc_span::source_map::Span;
+use rustc_span::source_map::{BytePos, Span};
use rustc_span::symbol::sym;
+use rustc_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceBase, PlaceWithHirId};
use super::SEARCH_IS_SOME;
/// lint searching an Iterator followed by `is_some()`
-/// or calling `find()` on a string followed by `is_some()`
+/// or calling `find()` on a string followed by `is_some()` or `is_none()`
+#[allow(clippy::too_many_arguments, clippy::too_many_lines)]
pub(super) fn check<'tcx>(
- cx: &LateContext<'tcx>,
+ cx: &LateContext<'_>,
expr: &'tcx hir::Expr<'_>,
search_method: &str,
- search_args: &'tcx [hir::Expr<'_>],
- is_some_args: &'tcx [hir::Expr<'_>],
+ is_some: bool,
+ search_recv: &hir::Expr<'_>,
+ search_arg: &'tcx hir::Expr<'_>,
+ is_some_recv: &hir::Expr<'_>,
method_span: Span,
) {
+ let option_check_method = if is_some { "is_some" } else { "is_none" };
// lint if caller of search is an Iterator
- if is_trait_method(cx, &is_some_args[0], sym::Iterator) {
+ if is_trait_method(cx, is_some_recv, sym::Iterator) {
let msg = format!(
- "called `is_some()` after searching an `Iterator` with `{}`",
- search_method
+ "called `{}()` after searching an `Iterator` with `{}`",
+ option_check_method, search_method
);
- let hint = "this is more succinctly expressed by calling `any()`";
- let search_snippet = snippet(cx, search_args[1].span, "..");
+ let search_snippet = snippet(cx, search_arg.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 mut applicability = Applicability::MachineApplicable;
let any_search_snippet = if_chain! {
if search_method == "find";
- if let hir::ExprKind::Closure(_, _, body_id, ..) = search_args[1].kind;
+ 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(_, _, ident, _) = strip_pat_refs(&closure_arg.pat).kind {
- let name = &*ident.name.as_str();
- Some(search_snippet.replace(&format!("*{}", name), name))
+ } else if let PatKind::Binding(_, binding_id, _, _) = strip_pat_refs(closure_arg.pat).kind {
+ // this binding is composed of at least two levels of references, so we need to remove one
+ let binding_type = cx.typeck_results().node_type(binding_id);
+ let innermost_is_ref = if let ty::Ref(_, inner,_) = binding_type.kind() {
+ matches!(inner.kind(), ty::Ref(_, innermost, _) if innermost.is_ref())
+ } else {
+ false
+ };
+
+ // `find()` provides a reference to the item, but `any` does not,
+ // so we should fix item usages for suggestion
+ if let Some(closure_sugg) = get_closure_suggestion(cx, search_arg, closure_body) {
+ applicability = closure_sugg.applicability;
+ if innermost_is_ref {
+ Some(closure_sugg.suggestion.replacen('&', "", 1))
+ } else {
+ Some(closure_sugg.suggestion)
+ }
+ } else if innermost_is_ref {
+ Some(search_snippet.replacen('&', "", 1))
+ } else {
+ Some(search_snippet.to_string())
+ }
} else {
None
}
}
};
// add note if not multi-line
- span_lint_and_sugg(
- cx,
- SEARCH_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,
- );
+ if is_some {
+ span_lint_and_sugg(
+ cx,
+ SEARCH_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,
+ );
+ } 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,
+ );
+ }
} else {
- span_lint_and_help(cx, SEARCH_IS_SOME, expr.span, &msg, None, hint);
+ let hint = format!(
+ "this is more succinctly expressed by calling `any()`{}",
+ if option_check_method == "is_none" {
+ " with negation"
+ } else {
+ ""
+ }
+ );
+ span_lint_and_help(cx, SEARCH_IS_SOME, expr.span, &msg, None, &hint);
}
}
// lint if `find()` is called by `String` or `&str`
else if search_method == "find" {
let is_string_or_str_slice = |e| {
let self_ty = cx.typeck_results().expr_ty(e).peel_refs();
- if is_type_diagnostic_item(cx, self_ty, sym::string_type) {
+ if is_type_diagnostic_item(cx, self_ty, sym::String) {
true
} else {
*self_ty.kind() == ty::Str
}
};
if_chain! {
- if is_string_or_str_slice(&search_args[0]);
- if is_string_or_str_slice(&search_args[1]);
+ if is_string_or_str_slice(search_recv);
+ if is_string_or_str_slice(search_arg);
then {
- let msg = "called `is_some()` after calling `find()` on a string";
- let mut applicability = Applicability::MachineApplicable;
- let find_arg = snippet_with_applicability(cx, search_args[1].span, "..", &mut applicability);
- span_lint_and_sugg(
- cx,
- SEARCH_IS_SOME,
- method_span.with_hi(expr.span.hi()),
- msg,
- "use `contains()` instead",
- format!("contains({})", find_arg),
- applicability,
- );
+ let msg = format!("called `{}()` after calling `find()` on a string", option_check_method);
+ match option_check_method {
+ "is_some" => {
+ let mut applicability = Applicability::MachineApplicable;
+ let find_arg = snippet_with_applicability(cx, search_arg.span, "..", &mut applicability);
+ span_lint_and_sugg(
+ cx,
+ SEARCH_IS_SOME,
+ method_span.with_hi(expr.span.hi()),
+ &msg,
+ "use `contains()` instead",
+ format!("contains({})", find_arg),
+ applicability,
+ );
+ },
+ "is_none" => {
+ let string = snippet(cx, search_recv.span, "..");
+ let mut applicability = Applicability::MachineApplicable;
+ let find_arg = snippet_with_applicability(cx, search_arg.span, "..", &mut applicability);
+ span_lint_and_sugg(
+ cx,
+ SEARCH_IS_SOME,
+ expr.span,
+ &msg,
+ "use `!_.contains()` instead",
+ format!("!{}.contains({})", string, find_arg),
+ applicability,
+ );
+ },
+ _ => (),
+ }
+ }
+ }
+ }
+}
+
+struct ClosureSugg {
+ applicability: Applicability,
+ suggestion: String,
+}
+
+// Build suggestion gradually by handling closure arg specific usages,
+// such as explicit deref and borrowing cases.
+// Returns `None` if no such use cases have been triggered in closure body
+fn get_closure_suggestion<'tcx>(
+ cx: &LateContext<'_>,
+ search_arg: &'tcx hir::Expr<'_>,
+ closure_body: &hir::Body<'_>,
+) -> Option<ClosureSugg> {
+ let mut visitor = DerefDelegate {
+ cx,
+ closure_span: search_arg.span,
+ next_pos: search_arg.span.lo(),
+ suggestion_start: String::new(),
+ applicability: Applicability::MachineApplicable,
+ };
+
+ 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);
+ });
+
+ if visitor.suggestion_start.is_empty() {
+ None
+ } else {
+ Some(ClosureSugg {
+ applicability: visitor.applicability,
+ suggestion: visitor.finish(),
+ })
+ }
+}
+
+struct DerefDelegate<'a, 'tcx> {
+ cx: &'a LateContext<'tcx>,
+ closure_span: Span,
+ next_pos: BytePos,
+ suggestion_start: String,
+ applicability: Applicability,
+}
+
+impl DerefDelegate<'_, 'tcx> {
+ pub fn finish(&mut self) -> String {
+ let end_span = Span::new(self.next_pos, self.closure_span.hi(), self.closure_span.ctxt());
+ let end_snip = snippet_with_applicability(self.cx, end_span, "..", &mut self.applicability);
+ format!("{}{}", self.suggestion_start, end_snip)
+ }
+}
+
+impl<'tcx> Delegate<'tcx> for DerefDelegate<'_, 'tcx> {
+ fn consume(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {}
+
+ fn borrow(&mut self, cmt: &PlaceWithHirId<'tcx>, _: HirId, _: ty::BorrowKind) {
+ if let PlaceBase::Local(id) = cmt.place.base {
+ let map = self.cx.tcx.hir();
+ let ident_str = map.name(id).to_string();
+ let span = map.span(cmt.hir_id);
+ let start_span = Span::new(self.next_pos, span.lo(), span.ctxt());
+ let mut start_snip = snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability);
+
+ if cmt.place.projections.is_empty() {
+ // handle item without any projection, that needs an explicit borrowing
+ // i.e.: suggest `&x` instead of `x`
+ self.suggestion_start.push_str(&format!("{}&{}", start_snip, ident_str));
+ } else {
+ // cases where a parent call is using the item
+ // i.e.: suggest `.contains(&x)` for `.find(|x| [1, 2, 3].contains(x)).is_none()`
+ if let Some(parent_expr) = get_parent_expr_for_hir(self.cx, cmt.hir_id) {
+ if let ExprKind::Call(_, call_args) | ExprKind::MethodCall(_, _, call_args, _) = parent_expr.kind {
+ let expr = self.cx.tcx.hir().expect_expr(cmt.hir_id);
+ let arg_ty_kind = self.cx.typeck_results().expr_ty(expr).kind();
+
+ if matches!(arg_ty_kind, ty::Ref(_, _, Mutability::Not)) {
+ let start_span = Span::new(self.next_pos, span.lo(), span.ctxt());
+ let start_snip =
+ snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability);
+ // do not suggest ampersand if the ident is the method caller
+ let ident_sugg = if !call_args.is_empty() && call_args[0].hir_id == cmt.hir_id {
+ format!("{}{}", start_snip, ident_str)
+ } else {
+ format!("{}&{}", start_snip, ident_str)
+ };
+ self.suggestion_start.push_str(&ident_sugg);
+ self.next_pos = span.hi();
+ return;
+ } else {
+ self.applicability = Applicability::Unspecified;
+ }
+ }
+ }
+
+ // handle item projections by removing one explicit deref
+ // i.e.: suggest `*x` instead of `**x`
+ let mut replacement_str = ident_str;
+
+ // handle index projection first
+ let index_handled = cmt.place.projections.iter().any(|proj| match proj.kind {
+ // Index projection like `|x| foo[x]`
+ // the index is dropped so we can't get it to build the suggestion,
+ // so the span is set-up again to get more code, using `span.hi()` (i.e.: `foo[x]`)
+ // instead of `span.lo()` (i.e.: `foo`)
+ ProjectionKind::Index => {
+ let start_span = Span::new(self.next_pos, span.hi(), span.ctxt());
+ start_snip = snippet_with_applicability(self.cx, start_span, "..", &mut self.applicability);
+ replacement_str.clear();
+ true
+ },
+ _ => false,
+ });
+
+ // looking for projections other that need to be handled differently
+ let other_projections_handled = cmt.place.projections.iter().enumerate().any(|(i, proj)| {
+ match proj.kind {
+ // Field projection like `|v| v.foo`
+ ProjectionKind::Field(idx, variant) => match cmt.place.ty_before_projection(i).kind() {
+ ty::Adt(def, ..) => {
+ replacement_str = format!(
+ "{}.{}",
+ replacement_str,
+ def.variants[variant].fields[idx as usize].ident.name.as_str()
+ );
+ true
+ },
+ ty::Tuple(_) => {
+ replacement_str = format!("{}.{}", replacement_str, idx);
+ true
+ },
+ _ => false,
+ },
+ // handled previously
+ ProjectionKind::Index |
+ // note: unable to trigger `Subslice` kind in tests
+ ProjectionKind::Subslice => false,
+ ProjectionKind::Deref => {
+ // explicit deref for arrays should be avoided in the suggestion
+ // i.e.: `|sub| *sub[1..4].len() == 3` is not expected
+ match cmt.place.ty_before_projection(i).kind() {
+ // dereferencing an array (i.e.: `|sub| sub[1..4].len() == 3`)
+ ty::Ref(_, inner, _) => {
+ matches!(inner.kind(), ty::Ref(_, innermost, _) if innermost.is_array())
+ },
+ _ => false,
+ }
+ },
+ }
+ });
+
+ // handle `ProjectionKind::Deref` if no special case detected
+ if !index_handled && !other_projections_handled {
+ 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.suggestion_start
+ .push_str(&format!("{}{}", start_snip, replacement_str));
}
+ self.next_pos = span.hi();
}
}
+
+ fn mutate(&mut self, _: &PlaceWithHirId<'tcx>, _: HirId) {}
+
+ fn fake_read(&mut self, _: rustc_typeck::expr_use_visitor::Place<'tcx>, _: FakeReadCause, _: HirId) {}
}
projects / rust.git / blobdiff