new lint: `large_stack_frames`

3 files changed, 82 insertions, 0 deletions

diff --git a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
index c546d95eb46..79af9cc9ac0 100644
--- a/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
+++ b/tests/ui-toml/toml_unknown_key/conf_unknown_key.stderr
@@ -44,6 +44,7 @@ error: error reading Clippy's configuration file: unknown field `foobar`, expect
            semicolon-inside-block-ignore-singleline
            semicolon-outside-block-ignore-multiline
            single-char-binding-names-threshold
+           stack-size-threshold
            standard-macro-braces
            suppress-restriction-lint-in-const
            third-party
diff --git a/tests/ui/large_stack_frames.rs b/tests/ui/large_stack_frames.rs
new file mode 100644
index 00000000000..cd9d0c8a67a
--- /dev/null
+++ b/tests/ui/large_stack_frames.rs
@@ -0,0 +1,44 @@
+#![allow(unused, incomplete_features)]
+#![warn(clippy::large_stack_frames)]
+#![feature(unsized_locals)]
+
+use std::hint::black_box;
+
+fn generic<T: Default>() {
+    let x = T::default();
+    black_box(&x);
+}
+
+fn unsized_local() {
+    let x: dyn std::fmt::Display = *(Box::new(1) as Box<dyn std::fmt::Display>);
+    black_box(&x);
+}
+
+struct ArrayDefault<const N: usize>([u8; N]);
+
+impl<const N: usize> Default for ArrayDefault<N> {
+    fn default() -> Self {
+        Self([0; N])
+    }
+}
+
+fn many_small_arrays() {
+    let x = [0u8; 500_000];
+    let x2 = [0u8; 500_000];
+    let x3 = [0u8; 500_000];
+    let x4 = [0u8; 500_000];
+    let x5 = [0u8; 500_000];
+    black_box((&x, &x2, &x3, &x4, &x5));
+}
+
+fn large_return_value() -> ArrayDefault<1_000_000> {
+    Default::default()
+}
+
+fn large_fn_arg(x: ArrayDefault<1_000_000>) {
+    black_box(&x);
+}
+
+fn main() {
+    generic::<ArrayDefault<1_000_000>>();
+}
diff --git a/tests/ui/large_stack_frames.stderr b/tests/ui/large_stack_frames.stderr
new file mode 100644
index 00000000000..d57df8596fe
--- /dev/null
+++ b/tests/ui/large_stack_frames.stderr
@@ -0,0 +1,37 @@
+error: this function allocates a large amount of stack space
+  --> $DIR/large_stack_frames.rs:25:1
+   |
+LL | / fn many_small_arrays() {
+LL | |     let x = [0u8; 500_000];
+LL | |     let x2 = [0u8; 500_000];
+LL | |     let x3 = [0u8; 500_000];
+...  |
+LL | |     black_box((&x, &x2, &x3, &x4, &x5));
+LL | | }
+   | |_^
+   |
+   = note: allocating large amounts of stack space can overflow the stack
+   = note: `-D clippy::large-stack-frames` implied by `-D warnings`
+
+error: this function allocates a large amount of stack space
+  --> $DIR/large_stack_frames.rs:34:1
+   |
+LL | / fn large_return_value() -> ArrayDefault<1_000_000> {
+LL | |     Default::default()
+LL | | }
+   | |_^
+   |
+   = note: allocating large amounts of stack space can overflow the stack
+
+error: this function allocates a large amount of stack space
+  --> $DIR/large_stack_frames.rs:38:1
+   |
+LL | / fn large_fn_arg(x: ArrayDefault<1_000_000>) {
+LL | |     black_box(&x);
+LL | | }
+   | |_^
+   |
+   = note: allocating large amounts of stack space can overflow the stack
+
+error: aborting due to 3 previous errors
+