Rollup merge of #123051 - matthiaskrgr:casetest, r=workingjubilee

did I mention that tests are super cool?

Fixes #81974
Fixes #84727
Fixes #92979

tests/ui/layout/failed-to-get-layout-for-type-error-ice-92979.rs

@@ -0,0 +1,78 @@
+// ICE: failed to get layout for [type error]
+// issue: rust-lang/rust#92979
+
+use std::fs;
+use std::fs::File;
+use std::io::Read;
+use std::convert::TryInto;
+
+fn get_file_as_byte_vec(filename: &String) -> Vec<u8> {
+    let mut f = File::open(&filename).expect("no file found");
+    let metadata = fs::metadata(&filename).expect("unable to read metadata");
+    let mut buffer = vec![0; metadata.len() as usize];
+    f.read(&mut buffer).expect("buffer overflow");
+
+    buffer
+}
+
+
+
+fn demo<T, const N: usize>(v: Vec<T>) -> [T; N] {
+    v.try_into()
+        .unwrap_or_else(|v: Vec<T>| panic!("Expected a Vec of length {} but it was {}", N, v.len()))
+}
+
+
+fn main() {
+
+    // Specify filepath
+    let file: &String = &String::from("SomeBinaryDataFileWith4ByteHeaders_f32s_and_u32s");
+
+    // Read file into a vector of bytes
+    let file_data = get_file_as_byte_vec(file);
+
+    // Print length of vector and first few values
+    let length = file_data.len();
+    println!("The read function read {} bytes", length);
+    println!("The first few bytes:");
+    for i in 0..20{
+        println!("{}", file_data[i]);
+    }
+
+    // Manually count just to make sure
+    let mut n: u64 = 0;
+    for data in file_data{
+        n += 1;
+    }
+    println!("We counted {} bytes", n);
+    assert!(n as usize == length, "Manual counting does not equal len method");
+
+    // Simulation parameters
+    const N: usize = 49627502;                // Number of Particles
+    const bs: f64 = 125.0;                  // Box Size
+    const HEADER_INCREMENT: u64 = 4*1;
+
+    // Initialize index and counter variables
+    let (mut j, mut pos, mut vel, mut id, mut mass): (u64, u64, u64, u64, u64) = (0, 0, 0, 0, 0);
+
+    // Unpack Position Data
+    j += HEADER_INCREMENT;
+    let mut position: Vec<f32> = Vec::new();
+    while position.len() < N*3 {
+
+        let p: Vec<u8> = Vec::new();
+        for item in 0i8..4 {
+            let item = item;
+            p.push(file_data[j as usize]);
+            j += 1;
+        }
+        &mut position[position.len()] = f32::from_be_bytes(demo(p));
+        //~^ ERROR invalid left-hand side of assignment
+    }
+
+    // Ensure position data is indeed position by checking values
+    for p in position {
+        assert!((p > 0.) & (p < 125.), "Not in box")
+    }
+
+}

tests/ui/layout/failed-to-get-layout-for-type-error-ice-92979.stderr

@@ -0,0 +1,16 @@
+error[E0070]: invalid left-hand side of assignment
+  --> $DIR/failed-to-get-layout-for-type-error-ice-92979.rs:69:39
+   |
+LL |         &mut position[position.len()] = f32::from_be_bytes(demo(p));
+   |         ----------------------------- ^
+   |         |
+   |         cannot assign to this expression
+   |
+help: consider dereferencing here to assign to the mutably borrowed value
+   |
+LL |         *&mut position[position.len()] = f32::from_be_bytes(demo(p));
+   |         +
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0070`.

tests/ui/layout/rust-call-abi-not-a-tuple-ice-81974.rs

@@ -0,0 +1,59 @@
+// ICE argument to function with "rust-call" ABI is not a tuple
+// issue: rust-lang/rust#81974
+
+#![feature(unboxed_closures)]
+#![feature(fn_traits)]
+
+use std::collections::HashMap;
+use std::hash::Hash;
+
+struct CachedFun<A, B> {
+    cache: HashMap<A, B>,
+    fun: fn(&mut CachedFun<A, B>, A) -> B,
+}
+
+impl<A: Eq + Hash, B> CachedFun<A, B> {
+    fn new(fun: fn(&mut Self, A) -> B) -> Self {
+        CachedFun {
+            cache: HashMap::new(),
+            fun,
+        }
+    }
+}
+
+impl<A, B> FnOnce<A> for CachedFun<A, B>
+//~^ ERROR type parameter to bare `FnOnce` trait must be a tuple
+where
+    A: Eq + Hash + Clone,
+    B: Clone,
+{
+    type Output = B;
+    extern "rust-call" fn call_once(mut self, a: A) -> Self::Output {
+    //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument
+        self.call_mut(a)
+        //~^ ERROR `A` is not a tuple
+    }
+}
+
+impl<A, B> FnMut<A> for CachedFun<A, B>
+//~^ ERROR type parameter to bare `FnMut` trait must be a tuple
+where
+    A: Eq + Hash + Clone,
+    B: Clone,
+{
+    extern "rust-call" fn call_mut(&mut self, a: A) -> Self::Output {
+    //~^ ERROR functions with the "rust-call" ABI must take a single non-self tuple argument
+        self.cache.get(&a).map(|a| a.clone()).unwrap_or_else(|| {
+            let b = (self.fun)(self, a.clone());
+            self.cache.insert(a, b.clone());
+            b
+        })
+    }
+}
+
+fn main() -> () {
+    let pesce = |y: &mut CachedFun<i32, i32>, x| x + 1;
+    let cachedcoso = CachedFun::new(pesce);
+    cachedcoso.call_once(1);
+    //~^ ERROR `i32` is not a tuple
+}

tests/ui/layout/rust-call-abi-not-a-tuple-ice-81974.stderr

@@ -0,0 +1,78 @@
+error[E0059]: type parameter to bare `FnOnce` trait must be a tuple
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:24:12
+   |
+LL | impl<A, B> FnOnce<A> for CachedFun<A, B>
+   |            ^^^^^^^^^ the trait `Tuple` is not implemented for `A`
+   |
+note: required by a bound in `FnOnce`
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+help: consider further restricting this bound
+   |
+LL |     A: Eq + Hash + Clone + std::marker::Tuple,
+   |                          ++++++++++++++++++++
+
+error[E0059]: type parameter to bare `FnMut` trait must be a tuple
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:38:12
+   |
+LL | impl<A, B> FnMut<A> for CachedFun<A, B>
+   |            ^^^^^^^^ the trait `Tuple` is not implemented for `A`
+   |
+note: required by a bound in `FnMut`
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+help: consider further restricting this bound
+   |
+LL |     A: Eq + Hash + Clone + std::marker::Tuple,
+   |                          ++++++++++++++++++++
+
+error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:31:5
+   |
+LL |     extern "rust-call" fn call_once(mut self, a: A) -> Self::Output {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `A`
+   |
+help: consider further restricting this bound
+   |
+LL |     A: Eq + Hash + Clone + std::marker::Tuple,
+   |                          ++++++++++++++++++++
+
+error[E0277]: functions with the "rust-call" ABI must take a single non-self tuple argument
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:44:5
+   |
+LL |     extern "rust-call" fn call_mut(&mut self, a: A) -> Self::Output {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Tuple` is not implemented for `A`
+   |
+help: consider further restricting this bound
+   |
+LL |     A: Eq + Hash + Clone + std::marker::Tuple,
+   |                          ++++++++++++++++++++
+
+error[E0277]: `A` is not a tuple
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:33:23
+   |
+LL |         self.call_mut(a)
+   |              -------- ^ the trait `Tuple` is not implemented for `A`
+   |              |
+   |              required by a bound introduced by this call
+   |
+note: required by a bound in `call_mut`
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+help: consider further restricting this bound
+   |
+LL |     A: Eq + Hash + Clone + std::marker::Tuple,
+   |                          ++++++++++++++++++++
+
+error[E0277]: `i32` is not a tuple
+  --> $DIR/rust-call-abi-not-a-tuple-ice-81974.rs:57:26
+   |
+LL |     cachedcoso.call_once(1);
+   |                --------- ^ the trait `Tuple` is not implemented for `i32`
+   |                |
+   |                required by a bound introduced by this call
+   |
+note: required by a bound in `call_once`
+  --> $SRC_DIR/core/src/ops/function.rs:LL:COL
+
+error: aborting due to 6 previous errors
+
+Some errors have detailed explanations: E0059, E0277.
+For more information about an error, try `rustc --explain E0059`.

tests/ui/traits/trait-selection-ice-84727.rs

@@ -0,0 +1,38 @@
+// ICE Where clause `Binder(..)` was applicable to `Obligation(..)` but now is not
+// issue: rust-lang/rust#84727
+
+struct Cell<Fg, Bg = Fg> {
+    foreground: Color<Fg>,
+    //~^ ERROR cannot find type `Color` in this scope
+    background: Color<Bg>,
+    //~^ ERROR cannot find type `Color` in this scope
+}
+
+trait Over<Bottom, Output> {
+    fn over(self) -> Output;
+}
+
+impl<TopFg, TopBg, BottomFg, BottomBg, NewFg, NewBg>
+    Over<Cell<BottomFg, BottomBg>, Cell<NewFg, NewBg>> for Cell<TopFg, TopBg>
+where
+    Self: Over<Color<BottomBg>, Cell<NewFg>>,
+    //~^ ERROR cannot find type `Color` in this scope
+{
+    fn over(self) -> Cell<NewFg> {
+    //~^ ERROR mismatched types
+        self.over();
+    }
+}
+
+impl<'b, TopFg, TopBg, BottomFg, BottomBg> Over<&Cell<BottomFg, BottomBg>, ()>
+    for Cell<TopFg, TopBg>
+where
+    Cell<TopFg, TopBg>: Over<Cell<BottomFg>, Cell<BottomFg>>,
+{
+    fn over(self) -> Cell<NewBg> {
+    //~^ ERROR cannot find type `NewBg` in this scope
+        self.over();
+    }
+}
+
+pub fn main() {}

tests/ui/traits/trait-selection-ice-84727.stderr

@@ -0,0 +1,47 @@
+error[E0412]: cannot find type `Color` in this scope
+  --> $DIR/trait-selection-ice-84727.rs:5:17
+   |
+LL |     foreground: Color<Fg>,
+   |                 ^^^^^ not found in this scope
+
+error[E0412]: cannot find type `Color` in this scope
+  --> $DIR/trait-selection-ice-84727.rs:7:17
+   |
+LL |     background: Color<Bg>,
+   |                 ^^^^^ not found in this scope
+
+error[E0412]: cannot find type `Color` in this scope
+  --> $DIR/trait-selection-ice-84727.rs:18:16
+   |
+LL |     Self: Over<Color<BottomBg>, Cell<NewFg>>,
+   |                ^^^^^ not found in this scope
+
+error[E0412]: cannot find type `NewBg` in this scope
+  --> $DIR/trait-selection-ice-84727.rs:32:27
+   |
+LL |     fn over(self) -> Cell<NewBg> {
+   |                           ^^^^^ not found in this scope
+   |
+help: you might be missing a type parameter
+   |
+LL | impl<'b, TopFg, TopBg, BottomFg, BottomBg, NewBg> Over<&Cell<BottomFg, BottomBg>, ()>
+   |                                          +++++++
+
+error[E0308]: mismatched types
+  --> $DIR/trait-selection-ice-84727.rs:21:22
+   |
+LL |     fn over(self) -> Cell<NewFg> {
+   |        ----          ^^^^^^^^^^^ expected `Cell<NewFg>`, found `()`
+   |        |
+   |        implicitly returns `()` as its body has no tail or `return` expression
+LL |
+LL |         self.over();
+   |                    - help: remove this semicolon to return this value
+   |
+   = note: expected struct `Cell<NewFg>`
+           found unit type `()`
+
+error: aborting due to 5 previous errors
+
+Some errors have detailed explanations: E0308, E0412.
+For more information about an error, try `rustc --explain E0308`.