Auto merge of #10423 - Alexendoo:array-size-threshold, r=flip1995

Fix array-size-threshold config deserialization error

changelog: Fix error when providing an `array-size-threshold` in `clippy.toml`

Not entirely sure why it doesn't want to deserialize a u128, but converting it after the fact is an easy enough fix

Fixes #10422

book/src/lint_configuration.md

@@ -306,7 +306,7 @@ The maximum number of lines a function or method can have
 ### array-size-threshold
 The maximum allowed size for arrays on the stack
 
-**Default Value:** `512000` (`u128`)
+**Default Value:** `512000` (`u64`)
 
 * [large_stack_arrays](https://rust-lang.github.io/rust-clippy/master/index.html#large_stack_arrays)
 * [large_const_arrays](https://rust-lang.github.io/rust-clippy/master/index.html#large_const_arrays)

clippy_lints/src/lib.rs

@@ -777,7 +777,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf:
     store.register_late_pass(|_| Box::new(mutable_debug_assertion::DebugAssertWithMutCall));
     store.register_late_pass(|_| Box::new(exit::Exit));
     store.register_late_pass(|_| Box::new(to_digit_is_some::ToDigitIsSome));
-    let array_size_threshold = conf.array_size_threshold;
+    let array_size_threshold = u128::from(conf.array_size_threshold);
     store.register_late_pass(move |_| Box::new(large_stack_arrays::LargeStackArrays::new(array_size_threshold)));
     store.register_late_pass(move |_| Box::new(large_const_arrays::LargeConstArrays::new(array_size_threshold)));
     store.register_late_pass(|_| Box::new(floating_point_arithmetic::FloatingPointArithmetic));

clippy_lints/src/utils/conf.rs

@@ -334,7 +334,7 @@ define_Conf! {
     /// Lint: LARGE_STACK_ARRAYS, LARGE_CONST_ARRAYS.
     ///
     /// The maximum allowed size for arrays on the stack
-    (array_size_threshold: u128 = 512_000),
+    (array_size_threshold: u64 = 512_000),
     /// Lint: VEC_BOX.
     ///
     /// The size of the boxed type in bytes, where boxing in a `Vec` is allowed

tests/ui-toml/array_size_threshold/array_size_threshold.rs

@@ -0,0 +1,10 @@
+#![allow(unused)]
+#![warn(clippy::large_const_arrays, clippy::large_stack_arrays)]
+
+const ABOVE: [u8; 11] = [0; 11];
+const BELOW: [u8; 10] = [0; 10];
+
+fn main() {
+    let above = [0u8; 11];
+    let below = [0u8; 10];
+}

tests/ui-toml/array_size_threshold/array_size_threshold.stderr

@@ -0,0 +1,29 @@
+error: large array defined as const
+  --> $DIR/array_size_threshold.rs:4:1
+   |
+LL | const ABOVE: [u8; 11] = [0; 11];
+   | -----^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   | |
+   | help: make this a static item: `static`
+   |
+   = note: `-D clippy::large-const-arrays` implied by `-D warnings`
+
+error: allocating a local array larger than 10 bytes
+  --> $DIR/array_size_threshold.rs:4:25
+   |
+LL | const ABOVE: [u8; 11] = [0; 11];
+   |                         ^^^^^^^
+   |
+   = help: consider allocating on the heap with `vec![0; 11].into_boxed_slice()`
+   = note: `-D clippy::large-stack-arrays` implied by `-D warnings`
+
+error: allocating a local array larger than 10 bytes
+  --> $DIR/array_size_threshold.rs:8:17
+   |
+LL |     let above = [0u8; 11];
+   |                 ^^^^^^^^^
+   |
+   = help: consider allocating on the heap with `vec![0u8; 11].into_boxed_slice()`
+
+error: aborting due to 3 previous errors
+

tests/ui-toml/array_size_threshold/clippy.toml

@@ -0,0 +1 @@
+array-size-threshold = 10

tests/ui/large_stack_arrays.rs

@@ -24,6 +24,7 @@ fn main() {
         [S { data: [0; 32] }; 5000],
         [Some(""); 20_000_000],
         [E::T(0); 5000],
+        [0u8; usize::MAX],
     );
 
     let good = (

tests/ui/large_stack_arrays.stderr

@@ -31,5 +31,13 @@ LL |         [E::T(0); 5000],
    |
    = help: consider allocating on the heap with `vec![E::T(0); 5000].into_boxed_slice()`
 
-error: aborting due to 4 previous errors
+error: allocating a local array larger than 512000 bytes
+  --> $DIR/large_stack_arrays.rs:27:9
+   |
+LL |         [0u8; usize::MAX],
+   |         ^^^^^^^^^^^^^^^^^
+   |
+   = help: consider allocating on the heap with `vec![0u8; usize::MAX].into_boxed_slice()`
+
+error: aborting due to 5 previous errors