add test for ICE: failed to get layout for [type error] #92979

Fixes #92979

Author: matthiaskrgr

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`.