summaryrefslogtreecommitdiffstats
path: root/xpcom/rust/nserror/src/lib.rs
diff options
context:
space:
mode:
Diffstat (limited to 'xpcom/rust/nserror/src/lib.rs')
-rw-r--r--xpcom/rust/nserror/src/lib.rs79
1 files changed, 79 insertions, 0 deletions
diff --git a/xpcom/rust/nserror/src/lib.rs b/xpcom/rust/nserror/src/lib.rs
new file mode 100644
index 0000000000..e4107d1b57
--- /dev/null
+++ b/xpcom/rust/nserror/src/lib.rs
@@ -0,0 +1,79 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use nsstring::{nsACString, nsCString};
+use std::error::Error;
+use std::fmt;
+
+/// The type of errors in gecko. Uses a newtype to provide additional type
+/// safety in Rust and #[repr(transparent)] to ensure the same representation
+/// as the C++ equivalent.
+#[repr(transparent)]
+#[allow(non_camel_case_types)]
+#[derive(Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
+pub struct nsresult(pub u32);
+
+impl nsresult {
+ pub fn failed(self) -> bool {
+ (self.0 >> 31) != 0
+ }
+
+ pub fn succeeded(self) -> bool {
+ !self.failed()
+ }
+
+ pub fn to_result(self) -> Result<(), nsresult> {
+ if self.failed() {
+ Err(self)
+ } else {
+ Ok(())
+ }
+ }
+
+ /// Get a printable name for the nsresult error code. This function returns
+ /// a nsCString<'static>, which implements `Display`.
+ pub fn error_name(self) -> nsCString {
+ let mut cstr = nsCString::new();
+ unsafe {
+ Gecko_GetErrorName(self, &mut *cstr);
+ }
+ cstr
+ }
+}
+
+impl fmt::Display for nsresult {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "{}", self.error_name())
+ }
+}
+
+impl fmt::Debug for nsresult {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ write!(f, "{}", self.error_name())
+ }
+}
+
+impl<T, E> From<Result<T, E>> for nsresult
+where
+ E: Into<nsresult>,
+{
+ fn from(result: Result<T, E>) -> nsresult {
+ match result {
+ Ok(_) => NS_OK,
+ Err(e) => e.into(),
+ }
+ }
+}
+
+impl Error for nsresult {}
+
+extern "C" {
+ fn Gecko_GetErrorName(rv: nsresult, cstr: *mut nsACString);
+}
+
+mod error_list {
+ include!(mozbuild::objdir_path!("xpcom/base/error_list.rs"));
+}
+
+pub use error_list::*;