Fix ICE in loops module

rust-lang · Aug 8, 2020 · 888657e · 888657e
1 parent 2d4c337
commit 888657e
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Showing 6 changed files with 30 additions and 15 deletions.
diff --git a/clippy_lints/src/loops.rs b/clippy_lints/src/loops.rs
@@ -2374,7 +2374,7 @@ fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCont
  match_type(cx, ty, &paths::BTREEMAP) ||
  is_type_diagnostic_item(cx, ty, sym!(hashmap_type)) {
  if method.ident.name == sym!(len) {
- let span = shorten_span(expr, sym!(collect));
+ let span = shorten_needless_collect_span(expr);
  span_lint_and_sugg(
  cx,
  NEEDLESS_COLLECT,
@@ -2386,20 +2386,20 @@ fn check_needless_collect_direct_usage<'tcx>(expr: &'tcx Expr<'_>, cx: &LateCont
  );
  }
  if method.ident.name == sym!(is_empty) {
- let span = shorten_span(expr, sym!(iter));
+ let span = shorten_needless_collect_span(expr);
  span_lint_and_sugg(
  cx,
  NEEDLESS_COLLECT,
  span,
  NEEDLESS_COLLECT_MSG,
  "replace with",
- "get(0).is_none()".to_string(),
+ "next().is_none()".to_string(),
  Applicability::MachineApplicable,
  );
  }
  if method.ident.name == sym!(contains) {
  let contains_arg = snippet(cx, args[1].span, "??");
- let span = shorten_span(expr, sym!(collect));
+ let span = shorten_needless_collect_span(expr);
  span_lint_and_then(
  cx,
  NEEDLESS_COLLECT,
@@ -2579,13 +2579,13 @@ fn detect_iter_and_into_iters<'tcx>(block: &'tcx Block<'tcx>, identifier: Ident)
  }
 }
 
-fn shorten_span(expr: &Expr<'_>, target_fn_name: Symbol) -> Span {
- let mut current_expr = expr;
- while let ExprKind::MethodCall(ref path, ref span, ref args, _) = current_expr.kind {
- if path.ident.name == target_fn_name {
+fn shorten_needless_collect_span(expr: &Expr<'_>) -> Span {
+ if_chain! {
+ if let ExprKind::MethodCall(.., args, _) = &expr.kind;
+ if let ExprKind::MethodCall(_, span, ..) = &args[0].kind;
+ then {
  return expr.span.with_lo(span.lo());
  }
- current_expr = &args[0];
  }
- unreachable!()
+ unreachable!();
 }
diff --git a/tests/ui/crashes/ice-5872.rs b/tests/ui/crashes/ice-5872.rs
@@ -0,0 +1,5 @@
+#![warn(clippy::needless_collect)]
+
+fn main() {
+ let _ = vec![1, 2, 3].into_iter().collect::<Vec<_>>().is_empty();
+}
diff --git a/tests/ui/crashes/ice-5872.stderr b/tests/ui/crashes/ice-5872.stderr
@@ -0,0 +1,10 @@
+error: avoid using `collect()` when not needed
+ --> $DIR/ice-5872.rs:4:39
+ |
+LL | let _ = vec![1, 2, 3].into_iter().collect::<Vec<_>>().is_empty();
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
+ |
+ = note: `-D clippy::needless-collect` implied by `-D warnings`
+
+error: aborting due to previous error
+
diff --git a/tests/ui/needless_collect.fixed b/tests/ui/needless_collect.fixed
@@ -5,11 +5,11 @@
 use std::collections::{BTreeSet, HashMap, HashSet};
 
 #[warn(clippy::needless_collect)]
-#[allow(unused_variables, clippy::iter_cloned_collect)]
+#[allow(unused_variables, clippy::iter_cloned_collect, clippy::iter_next_slice)]
 fn main() {
  let sample = [1; 5];
  let len = sample.iter().count();
- if sample.get(0).is_none() {
+ if sample.iter().next().is_none() {
  // Empty
  }
  sample.iter().cloned().any(|x| x == 1);

diff --git a/tests/ui/needless_collect.rs b/tests/ui/needless_collect.rs
@@ -5,7 +5,7 @@
 use std::collections::{BTreeSet, HashMap, HashSet};
 
 #[warn(clippy::needless_collect)]
-#[allow(unused_variables, clippy::iter_cloned_collect)]
+#[allow(unused_variables, clippy::iter_cloned_collect, clippy::iter_next_slice)]
 fn main() {
  let sample = [1; 5];
  let len = sample.iter().collect::<Vec<_>>().len();

diff --git a/tests/ui/needless_collect.stderr b/tests/ui/needless_collect.stderr
@@ -7,10 +7,10 @@ LL | let len = sample.iter().collect::<Vec<_>>().len();
  = note: `-D clippy::needless-collect` implied by `-D warnings`
 
 error: avoid using `collect()` when not needed
- --> $DIR/needless_collect.rs:12:15
+ --> $DIR/needless_collect.rs:12:22
  |
 LL | if sample.iter().collect::<Vec<_>>().is_empty() {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `get(0).is_none()`
+ |  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace with: `next().is_none()`
 
 error: avoid using `collect()` when not needed
  --> $DIR/needless_collect.rs:15:28