Parse the H packet

This is the simplest fix for bug luser#19.
tromey · Dec 20, 2017 · b9242ef · b9242ef
1 parent efaa64b
commit b9242ef
Showing 1 changed file with 17 additions and 1 deletion.
diff --git a/src/lib.rs b/src/lib.rs
@@ -140,6 +140,8 @@ enum Command<'a> {
     PingThread(ThreadId),
     CtrlC,
     UnknownVCommand,
+    /// Set the current thread for future commands, such as `ReadRegister`.
+    SetCurrentThread(ThreadId),
 }
 
 named!(gdbfeature<Known>, map!(map_res!(is_not_s!(";="), str::from_utf8), |s| {
@@ -235,6 +237,10 @@ fn v_command<'a>(i: &'a [u8]) -> IResult<&'a [u8], Command<'a>> {
                       |_| Command::UnknownVCommand
                   })
 }
+/// Parse the H packet.  Only `Hg` is needed, as the other forms are
+/// obsoleted by `vCont`.
+named!(parse_h_packet<&[u8], ThreadId>,
+       preceded!(tag!("Hg"), parse_thread_id));
 
 fn command<'a>(i: &'a [u8]) -> IResult<&'a [u8], Command<'a>> {
     alt!(i,
@@ -248,7 +254,7 @@ fn command<'a>(i: &'a [u8]) -> IResult<&'a [u8], Command<'a>> {
     // F RC,EE,CF;XX’
     | tag!("g") => { |_| Command::ReadGeneralRegisters }
     // G XX...
-    // H op thread-id
+    | parse_h_packet => { |thread_id| Command::SetCurrentThread(thread_id) }
     // i [addr[,nnn]]
     | tag!("k") => { |_| Command::Kill(None) }
     | read_memory => { |(addr, length)| Command::ReadMemory(addr, length) }
@@ -302,6 +308,10 @@ pub trait Handler {
     fn read_register(&self, _register: u64) -> Result<Vec<u8>, SimpleError> {
         Err(SimpleError::Error(NOT_IMPLEMENTED))
     }
+
+    fn set_current_thread(&self, _id: ThreadId) -> Result<(), SimpleError> {
+        Err(SimpleError::Error(NOT_IMPLEMENTED))
+    }
 }
 
 fn compute_checksum_incremental(bytes: &[u8], init: u8) -> u8 {
@@ -386,6 +396,12 @@ fn handle_packet<H, W>(data: &[u8],
                     Result::Err(SimpleError::Error(val)) => Response::Error(val),
                 }
             },
+            Command::SetCurrentThread(thread_id) => {
+                match handler.set_current_thread(thread_id) {
+                    Result::Ok(_) => Response::String("OK"),
+                    Result::Err(SimpleError::Error(val)) => Response::Error(val),
+                }
+            },
             Command::Query(Query::SupportedFeatures(features)) =>
                 handle_supported_features(handler, &features),
             Command::Query(Query::StartNoAckMode) => {