async structured data packet handling improvements

This change does the following:
* Changes the signature for the continuation delegate method that handles
  async structured data from accepting an already-parsed structured data
  element to taking just the packet contents.
* Moves the conversion of the JSON-async: packet contents from
  GDBRemoteClientBase to the continuation delegate method.
* Adds a new unit test for verifying that the $JSON-asyc: packets get
  decoded and that the decoded packets get forwarded on to the delegate
  for further processing. Thanks to Pavel for making that whole section of
  code easily unit testable!
* Tightens up the packet verification on reception of a $JSON-async:
  packet contents. The code prior to this change is susceptible to a
  segfault if a packet is carefully crafted that starts with $J but
  has a total length shorter than the length of "$JSON-async:".

Reviewers: labath, clayborg, zturner

Differential Revision: https://reviews.llvm.org/D23884

llvm-svn: 281121

1 files changed, 6 insertions, 7 deletions

diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
index f392895..15d7ec2 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteClientBase.h
@@ -25,14 +25,13 @@ public:
     virtual void HandleAsyncMisc(llvm::StringRef data) = 0;
     virtual void HandleStopReply() = 0;
 
-    //
-    /// Processes async structured data.
+    // =========================================================================
+    /// Process asynchronously-received structured data.
     ///
-    /// @return
-    ///    true if the data was handled; otherwise, false.
-    //
-    virtual bool
-    HandleAsyncStructuredData(const StructuredData::ObjectSP &object_sp) = 0;
+    /// @param[in] data
+    ///   The complete data packet, expected to start with JSON-async.
+    // =========================================================================
+    virtual void HandleAsyncStructuredDataPacket(llvm::StringRef data) = 0;
   };
 
   GDBRemoteClientBase(const char *comm_name, const char *listener_name);