1 files changed, 79 insertions, 0 deletions
diff --git a/third_party/rust/rure/src/error.rs b/third_party/rust/rure/src/error.rs
new file mode 100644
index 0000000000..a269a39135
--- /dev/null
+++ b/third_party/rust/rure/src/error.rs
@@ -0,0 +1,79 @@
+use std::ffi;
+use std::ffi::CString;
+use std::fmt;
+use std::str;
+
+use libc::c_char;
+use regex;
+
+#[derive(Debug)]
+pub struct Error {
+    message: Option<CString>,
+    kind: ErrorKind,
+}
+
+#[derive(Debug)]
+pub enum ErrorKind {
+    None,
+    Str(str::Utf8Error),
+    Regex(regex::Error),
+    Nul(ffi::NulError),
+}
+
+impl Error {
+    pub fn new(kind: ErrorKind) -> Error {
+        Error { message: None, kind: kind }
+    }
+
+    pub fn is_err(&self) -> bool {
+        match self.kind {
+            ErrorKind::None => false,
+            ErrorKind::Str(_) | ErrorKind::Regex(_) | ErrorKind::Nul(_) => {
+                true
+            }
+        }
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self.kind {
+            ErrorKind::None => write!(f, "no error"),
+            ErrorKind::Str(ref e) => e.fmt(f),
+            ErrorKind::Regex(ref e) => e.fmt(f),
+            ErrorKind::Nul(ref e) => e.fmt(f),
+        }
+    }
+}
+
+ffi_fn! {
+    fn rure_error_new() -> *mut Error {
+        Box::into_raw(Box::new(Error::new(ErrorKind::None)))
+    }
+}
+
+ffi_fn! {
+    fn rure_error_free(err: *mut Error) {
+        unsafe { drop(Box::from_raw(err)); }
+    }
+}
+
+ffi_fn! {
+    fn rure_error_message(err: *mut Error) -> *const c_char {
+        let err = unsafe { &mut *err };
+        let cmsg = match CString::new(format!("{}", err)) {
+            Ok(msg) => msg,
+            Err(err) => {
+                // I guess this can probably happen if the regex itself has a
+                // NUL, and that NUL re-occurs in the context presented by the
+                // error message. In this case, just show as much as we can.
+                let nul = err.nul_position();
+                let msg = err.into_vec();
+                CString::new(msg[0..nul].to_owned()).unwrap()
+            }
+        };
+        let p = cmsg.as_ptr();
+        err.message = Some(cmsg);
+        p
+    }
+}