llama_cpp_bindings/
ffi_error_reader.rs

1use std::ffi::{CStr, c_char};
2
3/// Reads a C error string, converts to Rust `String`, and frees the C memory.
4///
5/// # Safety
6///
7/// `error_ptr` must be either null or a valid pointer to a null-terminated
8/// C string allocated by `llama_rs_dup_string`.
9pub unsafe fn read_and_free_cpp_error(error_ptr: *mut c_char) -> String {
10    if error_ptr.is_null() {
11        return "unknown error".to_owned();
12    }
13
14    let message = unsafe { CStr::from_ptr(error_ptr) }
15        .to_string_lossy()
16        .into_owned();
17
18    unsafe { llama_cpp_bindings_sys::llama_rs_string_free(error_ptr) };
19
20    message
21}
22
23#[cfg(test)]
24mod tests {
25    use std::ffi::CString;
26    use std::ffi::c_char;
27
28    use super::read_and_free_cpp_error;
29
30    unsafe extern "C" {
31        fn strdup(s: *const c_char) -> *mut c_char;
32    }
33
34    #[test]
35    fn returns_unknown_for_null_pointer() {
36        let result = unsafe { read_and_free_cpp_error(std::ptr::null_mut()) };
37
38        assert_eq!(result, "unknown error");
39    }
40
41    #[test]
42    fn returns_message_for_valid_cstring_pointer() {
43        let original = CString::new("expected error message").unwrap();
44        let dup_ptr = unsafe { strdup(original.as_ptr()) };
45        assert!(!dup_ptr.is_null(), "strdup must allocate a copy");
46
47        let result = unsafe { read_and_free_cpp_error(dup_ptr) };
48
49        assert_eq!(result, "expected error message");
50    }
51}
llama_cpp_bindings/ffi_error_reader.rs

llama_cpp_bindings/
ffi_error_reader.rs
