Allow Target to override Arch's target description

src/gdbstub_impl/mod.rs

@@ -303,7 +303,9 @@ impl<T: Target, C: Connection> GdbStubImpl<T, C> {
                 // TODO: implement conditional breakpoint support (since that's kool).
                 // res.write_str("ConditionalBreakpoints+;")?;
 
-                if T::Arch::target_description_xml().is_some() {
+                // FIXME: `description_xml` returns an owned String, so this is not a very
+                // efficient way to check if it will return a custom description.
+                if target.description_xml().is_some() {
                     res.write_str(";qXfer:features:read+")?;
                 }
 
@@ -314,7 +316,7 @@ impl<T: Target, C: Connection> GdbStubImpl<T, C> {
                 HandlerStatus::NeedsOK
             }
             ext::Base::qXferFeaturesRead(cmd) => {
-                match T::Arch::target_description_xml() {
+                match target.description_xml() {
                     Some(xml) => {
                         let xml = xml.trim();
                         if cmd.offset >= xml.len() {

src/target/mod.rs

@@ -239,6 +239,16 @@ pub trait Target {
     fn section_offsets(&mut self) -> Option<ext::section_offsets::SectionOffsetsOps<Self>> {
         None
     }
+
+    /// Get the target description in XML.
+    /// In most cases you will not need to implement this method, and can simply
+    /// rely on the one defined in [`Arch`].
+    ///
+    /// Please refer to [`Arch::target_description_xml`] for further
+    /// documentation.
+    fn description_xml(&self) -> Option<&'static str> {
+        Self::Arch::target_description_xml()
+    }
 }
 
 macro_rules! impl_dyn_target {