SQUASHME: Fix up debug module

* Fix typos in `trace!` and `check!` macros that caused syntax errors
* Rename `trace!` to `fail!` to avoid name conflict with existing
`log::trace` function.
* Guard `Display` implementation of `manticore::Error` with the `log`
feature

Signed-off-by: Kesavan Yogeswaran <[email protected]>

Author: kesyog

src/debug.rs

@@ -69,6 +69,7 @@ impl<E> AsMut<E> for Error<E> {
     }
 }
 
+#[cfg(feature = "log")]
 impl<E: fmt::Display> fmt::Display for Error<E> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         struct DisplayAsDebug<'a, E>(&'a E);
@@ -118,30 +119,31 @@ macro_rules! check {
     ($cond:expr, $error:expr) => {
         if !$cond {
             let error = $error;
-            trace!(
+            fail!(
+                error,
+                "check failure: `{}`; returned {:?}",
+                stringify!($cond),
                 error,
-                "check failure: `{}`; returned {:?}"
-                stringify!($cond), error,
             )?;
         }
-    }
+    };
 }
 
 /// Logs a newly-created error value and returns it.
 ///
 /// This macro is the main way to generate [`Error`] values.
 ///
 /// For example, instead of writing `foo.ok_or(MyError)`, instead write
-/// `foo.ok_or_else(|| trace!(MyError))`.
-macro_rules! trace {
+/// `foo.ok_or_else(|| fail!(MyError))`.
+macro_rules! fail {
     ($error:expr, $($format:tt)+) => {{
         error!($($format)+);
-        $crate::debug::Error::__new($error)
+        Err($crate::debug::Error::__new($error))
     }};
     ($error:expr) => {{
         let error = $error;
         error!("generated error: `{:?}`", error);
-        $crate::debug::Error::__new(error)
+        Err($crate::debug::Error::__new(error))
     }};
 }