Rust: implement assertions

pkgs/rust/kernaux-sys/src/assert.rs

@@ -0,0 +1,67 @@
+use libc::{c_char, c_int};
+
+pub type AssertCB = unsafe extern "C" fn(*const c_char, c_int, *const c_char);
+
+#[link(name = "kernaux")]
+extern "C" {
+    #[link_name = "kernaux_assert_do"]
+    pub fn assert_do(file: *const c_char, line: c_int, msg: *const c_char);
+
+    #[link_name = "kernaux_assert_cb"]
+    pub static mut assert_cb: Option<AssertCB>;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    use std::ffi::{CStr, CString};
+    use std::ptr::null;
+
+    static mut LAST_FILE: *const c_char = null();
+    static mut LAST_LINE: c_int = 0;
+    static mut LAST_MSG: *const c_char = null();
+
+    unsafe extern "C" fn some_assert_cb(
+        file: *const c_char,
+        line: c_int,
+        msg: *const c_char,
+    ) {
+        LAST_FILE = file;
+        LAST_LINE = line;
+        LAST_MSG = msg;
+    }
+
+    #[test]
+    fn default() {
+        unsafe {
+            assert_cb = None;
+            assert!(assert_cb.is_none());
+
+            assert_cb = Some(some_assert_cb);
+            match assert_cb {
+                None => panic!(),
+                Some(actual_assert_cb) => {
+                    assert!(actual_assert_cb == some_assert_cb)
+                }
+            }
+
+            let file_cstr = CString::new("foo.rs").unwrap();
+            let msg_cstr = CString::new("bar").unwrap();
+
+            assert_do(
+                file_cstr.as_ptr() as *const c_char,
+                123,
+                msg_cstr.as_ptr() as *const c_char,
+            );
+
+            let file = CStr::from_ptr(LAST_FILE).to_str().unwrap();
+            let line = LAST_LINE;
+            let msg = CStr::from_ptr(LAST_MSG).to_str().unwrap();
+
+            assert_eq!(file, "foo.rs");
+            assert_eq!(line, 123);
+            assert_eq!(msg, "bar");
+        }
+    }
+}

pkgs/rust/kernaux-sys/src/lib.rs

@@ -3,6 +3,8 @@
 #[cfg(test)]
 extern crate std;
 
+mod assert;
 mod ntoa;
 
+pub use assert::*;
 pub use ntoa::*;