ctest 0.5.1

/* This file was autogenerated by ctest; do not modify directly */
{#- ↑ Doesn't apply here, this is the template! +#}

{%- let ctx = self.template +%}
{%- let ctest_extern = self.extern_keyword +%}

/// As this file is sometimes built using rustc, crate level attributes
/// are not allowed at the top-level, so we hack around this by keeping it
/// inside of a module.
mod generated_tests {
    #![allow(non_snake_case)]
    // FIXME: rustc raises this lint on `#[non_exhaustive]` structs, even via a pointer. Once
    // this is fixed we should deny it.
    #![allow(improper_ctypes)]
    #![deny(improper_ctypes_definitions)]
    #[allow(unused_imports)]
    use std::ffi::{CStr, c_int, c_char, c_uint};
    use std::fmt::{Debug, Write};
    use std::sync::atomic::{AtomicBool, AtomicUsize, Ordering};
    #[allow(unused_imports)]
    use std::{mem, ptr, slice};
    #[allow(unused_imports)]
    use std::mem::{MaybeUninit, offset_of};

    use super::*;

    pub static FAILED: AtomicBool = AtomicBool::new(false);
    pub static NTESTS: AtomicUsize = AtomicUsize::new(0);

    /// Check that the value returned from the Rust and C side in a certain test is equivalent.
    ///
    /// Internally it will remember which checks failed and how many tests have been run.
    fn check_same<T: PartialEq + Debug>(rust: T, c: T, attr: &str) {
        if rust != c {
            eprintln!("bad {attr}: rust: {rust:?} != c {c:?}");
            FAILED.store(true, Ordering::Relaxed);
        } else {
            NTESTS.fetch_add(1, Ordering::Relaxed);
        }
    }

    fn check_same_bytes(rust: &[u8], c: &[u8], attr: &str) {
        if rust == c {
            NTESTS.fetch_add(1, Ordering::Relaxed);
            return;
        }

        FAILED.store(true, Ordering::Relaxed);
        // Buffer to a string so we don't write individual bytes to stdio
        let mut s = String::new();
        if rust.len() == c.len() {
            for (i, (&rb, &cb)) in rust.iter().zip(c.iter()).enumerate() {
                if rb != cb {
                    writeln!(
                        s, "bad {attr} at byte {i}: rust: {rb:?} ({rb:#x}) != c {cb:?} ({cb:#x})"
                    ).unwrap();
                    break;
                }
            }
        } else {
            writeln!(s, "bad {attr}: rust len {} != c len {}", rust.len(), c.len()).unwrap();
        }

        write!(s, "    rust bytes:").unwrap();
        for b in rust {
            write!(s, " {b:02x}").unwrap();
        }
        write!(s, "\n    c bytes:   ").unwrap();
        for b in c {
            write!(s, " {b:02x}").unwrap();
        }
        eprintln!("{s}");
    }


/* Test that the string constant is the same in both Rust and C.
 * While fat pointers can't be translated, we instead use * const c_char.
 */
{%- for const_cstr in ctx.const_cstr_tests +%}

    pub fn {{ const_cstr.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_const_cstr__{{ const_cstr.id }}() -> *const c_char;
        }

        {# /* SAFETY: we assume that `c_char` pointer consts are for C strings. */ #}
        let r_val = unsafe {
            let r_ptr: *const c_char = {{ const_cstr.rust_val }};
            assert!(!r_ptr.is_null(), "const `{{ const_cstr.rust_val }}` is null");
            CStr::from_ptr(r_ptr)
        };

        {# /* SAFETY: FFI call returns a valid C string. */ #}
        let c_val = unsafe {
            let c_ptr: *const c_char = ctest_const_cstr__{{ const_cstr.id }}();
            CStr::from_ptr(c_ptr)
        };

        check_same(r_val, c_val, "const `{{ const_cstr.rust_val }}` string");
    }
{%- endfor +%}


/* Test that the value of the constant is the same in both Rust and C.
 *
 * This performs a byte by byte comparison of the constant value.
 */
{%- for constant in ctx.const_tests +%}

    pub fn {{ constant.test_name }}() {
        type T = {{ constant.rust_ty }};
        {{ ctest_extern }} "C" {
            fn ctest_const__{{ constant.id }}() -> *const T;
        }

        {#
            /* HACK: The slices may contain uninitialized data! We do this because
             * there isn't a good way to recursively iterate all fields. */
        #}

        let r_val: T = {{ constant.rust_val }};
        let r_bytes = unsafe {
            slice::from_raw_parts(ptr::from_ref(&r_val).cast::<u8>(), size_of::<T>())
        };

        let c_bytes = unsafe {
            let c_ptr: *const T = ctest_const__{{ constant.id }}();
            slice::from_raw_parts(c_ptr.cast::<u8>(), size_of::<T>())
        };

        check_same_bytes(r_bytes, c_bytes, "`{{ constant.rust_val }}` value");
    }
{%- endfor +%}


/* Compare the size and alignment of the type in Rust and C, making sure they are the same. */
{%- for item in ctx.size_align_tests +%}

    pub fn {{ item.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_size_of__{{ item.id }}() -> u64;
            fn ctest_align_of__{{ item.id }}() -> u64;
        }

        let rust_size = size_of::<{{ item.rust_ty }}>() as u64;
        let c_size = unsafe { ctest_size_of__{{ item.id }}() };

        let rust_align = align_of::<{{ item.rust_ty }}>() as u64;
        let c_align = unsafe { ctest_align_of__{{ item.id }}() };

        check_same(rust_size, c_size, "`{{ item.id }}` size");
        check_same(rust_align, c_align, "`{{ item.id }}` align");
    }
{%- endfor +%}


/* Make sure that the signededness of a type alias in Rust and C is the same.
 *
 * This is done by casting 0 to that type and flipping all of its bits. For unsigned types,
 * this would result in a value larger than zero. For signed types, this results in a value
 * smaller than 0.
 */
{%- for alias in ctx.signededness_tests +%}

    pub fn {{ alias.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_signededness_of__{{ alias.id }}() -> u32;
        }
        let all_ones = !(0 as {{ alias.id }});
        let all_zeros = 0 as {{ alias.id }};
        let c_is_signed = unsafe { ctest_signededness_of__{{ alias.id }}() };

        check_same((all_ones < all_zeros) as u32, c_is_signed, "`{{ alias.id }}` signed");
    }
{%- endfor +%}


/* Make sure that the offset and size of a field in a struct/union is the same. */
{%- for item in ctx.field_size_offset_tests +%}

    pub fn {{ item.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_offset_of__{{ item.id }}__{{ item.field.ident() }}() -> u64;
            fn ctest_size_of__{{ item.id }}__{{ item.field.ident() }}() -> u64;
        }

        let uninit_ty = MaybeUninit::<{{ item.id }}>::zeroed();
        let uninit_ty = uninit_ty.as_ptr();

        {# /* SAFETY: we assume the field access doesn't wrap */ #}
        let ty_ptr = unsafe { &raw const (*uninit_ty).{{ item.field.rust_ident() }}   };
        {# /* SAFETY: we assume that all zeros is a valid bitpattern for `ty_ptr`, otherwise the
            * test should be skipped. */ #}
        let val = unsafe { ty_ptr.read_unaligned() };

        {# /* SAFETY: FFI call with no preconditions */ #}
        let ctest_field_offset = unsafe { ctest_offset_of__{{ item.id }}__{{ item.field.ident() }}() };
        check_same(offset_of!({{ item.id }}, {{ item.field.rust_ident() }}) as u64, ctest_field_offset,
            "field offset `{{ item.field.rust_ident() }}` of `{{ item.id }}`");
        {# /* SAFETY: FFI call with no preconditions */ #}
        let ctest_field_size = unsafe { ctest_size_of__{{ item.id }}__{{ item.field.ident() }}() };
        check_same(size_of_val(&val) as u64, ctest_field_size,
            "field size `{{ item.field.rust_ident() }}` of `{{ item.id }}`");
    }
{%- endfor +%}


/* Tests if the pointer to the field is the same in Rust and C. */
{%- for item in ctx.field_ptr_tests +%}

    pub fn {{ item.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_field_ptr__{{ item.id }}__{{ item.field.ident() }}(a: *const {{ item.id }}) -> *mut u8;
        }

        let uninit_ty = MaybeUninit::<{{ item.id }}>::zeroed();
        let ty_ptr = uninit_ty.as_ptr();
        // SAFETY: We don't read `field_ptr`, only compare the pointer itself.
        // The assumption is made that this does not wrap the address space.
        let field_ptr = unsafe { &raw const ((*ty_ptr).{{ item.field.rust_ident() }}) };

        // SAFETY: FFI call with no preconditions
        let ctest_field_ptr = unsafe { ctest_field_ptr__{{ item.id }}__{{ item.field.ident() }}(ty_ptr) };
        check_same(field_ptr.cast(), ctest_field_ptr,
            "field pointer access `{{ item.field.rust_ident() }}` of `{{ item.id }}`");
    }

{%- endfor +%}

/* Generates a padding map for a specific type.
 *
 * Essentially, it returns a list of bytes, whose length is equal to the size of the type in
 * bytes. Each element corresponds to a byte and has two values. `true` if the byte is padding,
 * and `false` if the byte is not padding.
 *
 * For aliases we assume that there are no padding bytes, for structs and unions,
 * if there are no fields, then everything is padding, if there are fields, then we have to
 * go through each field and figure out the padding.
 */
{%- for item in ctx.roundtrip_tests +%}

    fn roundtrip_padding__{{ item.id }}() -> Vec<bool> {
        if {{ item.fields.len() }} == 0 {
            {# /* FIXME(ctest): What if it's an alias to a struct/union? */ #}
            return vec![!{{ item.is_alias }}; size_of::<{{ item.id }}>()]
        }

        {# /* If there are no fields, v and bar become unused. */ #}
        #[allow(unused_mut)]
        let mut v = Vec::<(usize, usize)>::new();
        #[allow(unused_variables)]
        let bar = MaybeUninit::<{{ item.id }}>::zeroed();
        #[allow(unused_variables)]
        let bar = bar.as_ptr();
        {%- for field in item.fields +%}

        let ty_ptr = unsafe { &raw const ((*bar).{{ field.rust_ident() }}) };
        let val = unsafe { ty_ptr.read_unaligned() };

        let size = size_of_val(&val);
        let off = offset_of!({{ item.id }}, {{ field.rust_ident() }});
        v.push((off, size));
        {%- endfor +%}
        {# /* This vector contains `true` if the byte is padding and `false` if the byte is not
         * padding. Initialize all bytes as:
         *  - padding if we have fields, this means that only the fields will be checked
         *  - no-padding if we have a type alias: if this causes problems the type alias should
         *    be skipped */ #}
        let mut is_padding_byte = vec![true; size_of::<{{ item.id }}>()];
        for (off, size) in &v {
            for i in 0..*size {
                is_padding_byte[off + i] = false;
            }
        }
        is_padding_byte
    }

    {# /* Tests whether a type alias when passed to C and back to Rust remains unchanged.
     *
     * It checks if the size is the same as well as if the padding bytes are all in the
     * correct place. For this test to be sound, `T` must be valid for any bitpattern. */ #}
    pub fn {{ item.test_name }}() {
        type U = {{ item.id }};
        {{ ctest_extern }} "C" {
            fn ctest_size_of__{{ item.id }}() -> u64;
            fn ctest_roundtrip__{{ item.id }}(
                input: MaybeUninit<U>, is_padding_byte: *const bool, value_bytes: *mut u8
            ) -> U;
        }

        const SIZE: usize = size_of::<U>();

        let is_padding_byte = roundtrip_padding__{{ item.id }}();
        let mut expected = vec![0u8; SIZE];
        let mut input = MaybeUninit::<U>::zeroed();

        let input_ptr = input.as_mut_ptr().cast::<u8>();

        {# /* Fill the uninitialized memory with a deterministic pattern.
         * From Rust to C: every byte will be labelled from 1 to 255, with 0 turning into 42.
         * From C to Rust: every byte will be inverted from before (254 -> 1), but 0 is still 42.
         */ #}
        for i in 0..SIZE {
            let c: u8 = (i % 256) as u8;
            let c = if c == 0 { 42 } else { c };
            let d: u8 = 255_u8 - (i % 256) as u8;
            let d = if d == 0 { 42 } else { d };
            unsafe {
                input_ptr.add(i).write_volatile(c);
                expected[i] = d;
            }
        }

        let c_size = unsafe { ctest_size_of__{{ item.id }}() } as usize;
        if SIZE != c_size {
            FAILED.store(true, Ordering::Relaxed);
            eprintln!(
                "size of `{{ item.c_ty }}` is {c_size} in C and {SIZE} in Rust\n",
            );
            return;
        }

        let mut c_value_bytes = vec![0; size_of::<{{ item.id }}>()];
        let r: U = unsafe {
            ctest_roundtrip__{{ item.id }}(input, is_padding_byte.as_ptr(), c_value_bytes.as_mut_ptr())
        };

        {# /* Check that the value bytes as read from C match the byte we sent from Rust. */ #}
        for (i, is_padding_byte) in is_padding_byte.iter().enumerate() {
            if *is_padding_byte { continue; }
            let rust = unsafe { *input_ptr.add(i) };
            let c = c_value_bytes[i];
            if rust != c {
                eprintln!("rust[{}] = {} != {} (C): Rust `{{ item.id }}` -> C", i, rust, c);
                FAILED.store(true, Ordering::Relaxed);
            }
        }

        {# /* Check that value returned from C contains the bytes we expect. */ #}
        for (i, is_padding_byte) in is_padding_byte.iter().enumerate() {
            if *is_padding_byte { continue; }
            let rust = expected[i] as usize;
            let c = unsafe { (&raw const r).cast::<u8>().add(i).read_volatile() as usize };
            if rust != c {
                eprintln!(
                    "rust [{i}] = {rust} != {c} (C): C `{{ item.id }}` -> Rust",
                );
                FAILED.store(true, Ordering::Relaxed);
            }
        }
    }
{%- endfor +%}

/* Check if the Rust and C side function pointers point to the same underlying function. */
{%- for item in ctx.foreign_fn_tests +%}

    pub fn {{ item.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_foreign_fn__{{ item.id }}() -> unsafe extern "C" fn();
        }
        let actual = unsafe { ctest_foreign_fn__{{ item.id }}() } as u64;
        let expected = {{ item.id }} as *const () as u64;
        check_same(actual, expected, "`{{ item.id }}` function pointer");
    }
{%- endfor +%}

/* Tests if the pointer to the static variable matches in both Rust and C. */
{%- for static_ in ctx.foreign_static_tests +%}

    pub fn {{ static_.test_name }}() {
        {{ ctest_extern }} "C" {
            fn ctest_static__{{ static_.id }}() -> *const {{ static_.rust_ty }};
        }
        let actual = (&raw const {{ static_.id }}).addr();
        let expected = unsafe {
            ctest_static__{{ static_.id }}().addr()
        };
        check_same(actual, expected, "`{{ static_.id }}` static");
    }
{%- endfor +%}
}

use generated_tests::*;

fn main() {
    println!("RUNNING ALL TESTS");
    run_all();
    if FAILED.load(std::sync::atomic::Ordering::Relaxed) {
        panic!("some tests failed");
    } else {
        println!(
            "PASSED {} tests",
            NTESTS.load(std::sync::atomic::Ordering::Relaxed)
        );
    }
}

// Run all tests by calling the functions that define them.
// FIXME(ctest): Maybe consider running the tests in parallel, since everything is independent
// and we already use atomics.
fn run_all() {
    {%- for test in ctx.test_idents +%}
    {{ test }}();
    {%- endfor +%}
}