Basic tests for size_of_val and min_alig_of_val (rust-lang#1101)

* Basic tests for `size_of_val` and `min_alig_of_val`

* Fix format

* Add cases for `repr(C)` struct

* Add note

Author: adpaco-aws

tests/kani/Intrinsics/AlignOfVal/align_of_basic.rs

@@ -0,0 +1,52 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Check that we get the expected results for the `min_align_of_val` intrinsic
+// with common data types. Note that these tests assume an x86_64 architecture,
+// which is the only architecture supported by Kani at the moment.
+#![feature(core_intrinsics)]
+use std::intrinsics::min_align_of_val;
+
+struct MyStruct {
+    val: u32,
+}
+
+#[repr(C)]
+struct CStruct {
+    a: u8,
+    b: i32,
+}
+
+enum MyEnum {
+    Variant,
+}
+
+#[kani::proof]
+fn main() {
+    unsafe {
+        // Scalar types
+        assert!(min_align_of_val(&0i8) == 1);
+        assert!(min_align_of_val(&0i16) == 2);
+        assert!(min_align_of_val(&0i32) == 4);
+        assert!(min_align_of_val(&0i64) == 8);
+        assert!(min_align_of_val(&0i128) == 8);
+        assert!(min_align_of_val(&0isize) == 8);
+        assert!(min_align_of_val(&0u8) == 1);
+        assert!(min_align_of_val(&0u16) == 2);
+        assert!(min_align_of_val(&0u32) == 4);
+        assert!(min_align_of_val(&0u64) == 8);
+        assert!(min_align_of_val(&0u128) == 8);
+        assert!(min_align_of_val(&0usize) == 8);
+        assert!(min_align_of_val(&0f32) == 4);
+        assert!(min_align_of_val(&0f64) == 8);
+        assert!(min_align_of_val(&false) == 1);
+        assert!(min_align_of_val(&(0 as char)) == 4);
+        // Compound types (tuple and array)
+        assert!(min_align_of_val(&(0i32, 0i32)) == 4);
+        assert!(min_align_of_val(&[0i32; 5]) == 4);
+        // Custom data types (struct and enum)
+        assert!(min_align_of_val(&MyStruct { val: 0u32 }) == 4);
+        assert!(min_align_of_val(&MyEnum::Variant) == 1);
+        assert!(min_align_of_val(&CStruct { a: 0u8, b: 0i32 }) == 4);
+    }
+}

tests/kani/Intrinsics/SizeOfVal/size_of_basic.rs

@@ -0,0 +1,52 @@
+// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+// SPDX-License-Identifier: Apache-2.0 OR MIT
+
+// Check that we get the expected results for the `size_of_val` intrinsic with
+// common data types. Note that these tests assume an x86_64 architecture, which
+// is the only architecture supported by Kani at the moment.
+#![feature(core_intrinsics)]
+use std::intrinsics::size_of_val;
+
+struct MyStruct {
+    val: u32,
+}
+
+#[repr(C)]
+struct CStruct {
+    a: u8,
+    b: i32,
+}
+
+enum MyEnum {
+    Variant,
+}
+
+#[kani::proof]
+fn main() {
+    unsafe {
+        // Scalar types
+        assert!(size_of_val(&0i8) == 1);
+        assert!(size_of_val(&0i16) == 2);
+        assert!(size_of_val(&0i32) == 4);
+        assert!(size_of_val(&0i64) == 8);
+        assert!(size_of_val(&0i128) == 16);
+        assert!(size_of_val(&0isize) == 8);
+        assert!(size_of_val(&0u8) == 1);
+        assert!(size_of_val(&0u16) == 2);
+        assert!(size_of_val(&0u32) == 4);
+        assert!(size_of_val(&0u64) == 8);
+        assert!(size_of_val(&0u128) == 16);
+        assert!(size_of_val(&0usize) == 8);
+        assert!(size_of_val(&0f32) == 4);
+        assert!(size_of_val(&0f64) == 8);
+        assert!(size_of_val(&false) == 1);
+        assert!(size_of_val(&(0 as char)) == 4);
+        // Compound types (tuple and array)
+        assert!(size_of_val(&(0i32, 0i32)) == 8);
+        assert!(size_of_val(&[0i32; 5]) == 20);
+        // Custom data types (struct and enum)
+        assert!(size_of_val(&MyStruct { val: 0u32 }) == 4);
+        assert!(size_of_val(&MyEnum::Variant) == 0);
+        assert!(size_of_val(&CStruct { a: 0u8, b: 0i32 }) == 8);
+    }
+}