[lldb-dap] Send a 'process' event on restart. (#163833)

When we restart a process, send an updated 'process' event describing
the newly launched process.

I also updated the `isLocalProcess` value based on if we're on the
'host' platform or not.

lldb/bindings/interface/SBPlatformExtensions.i

@@ -0,0 +1,7 @@
+%extend lldb::SBPlatform {
+#ifdef SWIGPYTHON
+    %pythoncode %{
+        is_host = property(IsHost, None, doc='''A read only property that returns a boolean value that indiciates if this platform is the host platform.''')
+    %}
+#endif
+}

lldb/bindings/interfaces.swig

@@ -53,6 +53,7 @@
 %include "./interface/SBModuleSpecDocstrings.i"
 %include "./interface/SBMutexExtensions.i"
 %include "./interface/SBPlatformDocstrings.i"
+%include "./interface/SBPlatformExtensions.i"
 %include "./interface/SBProcessDocstrings.i"
 %include "./interface/SBProcessInfoDocstrings.i"
 %include "./interface/SBProgressDocstrings.i"

lldb/include/lldb/API/SBPlatform.h

@@ -112,6 +112,9 @@ public:
 
   bool IsValid() const;
 
+  /// Returns true if this platform is the host platform, otherwise false.
+  bool IsHost() const;
+
   void Clear();
 
   const char *GetWorkingDirectory();

lldb/source/API/SBPlatform.cpp

@@ -331,6 +331,11 @@ SBPlatform::operator bool() const {
   return m_opaque_sp.get() != nullptr;
 }
 
+bool SBPlatform::IsHost() const {
+  LLDB_INSTRUMENT_VA(this);
+  return m_opaque_sp.get() != nullptr && m_opaque_sp->IsHost();
+}
+
 void SBPlatform::Clear() {
   LLDB_INSTRUMENT_VA(this);
 

lldb/tools/lldb-dap/EventHelper.cpp

@@ -15,6 +15,7 @@
 #include "Protocol/ProtocolRequests.h"
 #include "Protocol/ProtocolTypes.h"
 #include "lldb/API/SBFileSpec.h"
+#include "lldb/API/SBPlatform.h"
 #include "llvm/Support/Error.h"
 #include <utility>
 
@@ -78,11 +79,9 @@ void SendExtraCapabilities(DAP &dap) {
 //     { "$ref": "#/definitions/Event" },
 //     {
 //       "type": "object",
-//       "description": "Event message for 'process' event type. The event
-//                       indicates that the debugger has begun debugging a
-//                       new process. Either one that it has launched, or one
-//                       that it has attached to.",
-//       "properties": {
+//       "description": "The event indicates that the debugger has begun
+//       debugging a new process. Either one that it has launched, or one that
+//       it has attached to.", "properties": {
 //         "event": {
 //           "type": "string",
 //           "enum": [ "process" ]
@@ -93,31 +92,37 @@ void SendExtraCapabilities(DAP &dap) {
 //             "name": {
 //               "type": "string",
 //               "description": "The logical name of the process. This is
-//                               usually the full path to process's executable
-//                               file. Example: /home/myproj/program.js."
+//               usually the full path to process's executable file. Example:
+//               /home/example/myproj/program.js."
 //             },
 //             "systemProcessId": {
 //               "type": "integer",
-//               "description": "The system process id of the debugged process.
-//                               This property will be missing for non-system
-//                               processes."
+//               "description": "The process ID of the debugged process, as
+//               assigned by the operating system. This property should be
+//               omitted for logical processes that do not map to operating
+//               system processes on the machine."
 //             },
 //             "isLocalProcess": {
 //               "type": "boolean",
 //               "description": "If true, the process is running on the same
-//                               computer as the debug adapter."
+//               computer as the debug adapter."
 //             },
 //             "startMethod": {
 //               "type": "string",
 //               "enum": [ "launch", "attach", "attachForSuspendedLaunch" ],
 //               "description": "Describes how the debug engine started
-//                               debugging this process.",
-//               "enumDescriptions": [
+//               debugging this process.", "enumDescriptions": [
 //                 "Process was launched under the debugger.",
 //                 "Debugger attached to an existing process.",
-//                 "A project launcher component has launched a new process in
-//                  a suspended state and then asked the debugger to attach."
+//                 "A project launcher component has launched a new process in a
+//                 suspended state and then asked the debugger to attach."
 //               ]
+//             },
+//             "pointerSize": {
+//               "type": "integer",
+//               "description": "The size of a pointer or address for this
+//               process, in bits. This value may be used by clients when
+//               formatting addresses for display."
 //             }
 //           },
 //           "required": [ "name" ]
@@ -126,7 +131,7 @@ void SendExtraCapabilities(DAP &dap) {
 //       "required": [ "event", "body" ]
 //     }
 //   ]
-// }
+// },
 void SendProcessEvent(DAP &dap, LaunchMethod launch_method) {
   lldb::SBFileSpec exe_fspec = dap.target.GetExecutable();
   char exe_path[PATH_MAX];
@@ -136,7 +141,8 @@ void SendProcessEvent(DAP &dap, LaunchMethod launch_method) {
   EmplaceSafeString(body, "name", exe_path);
   const auto pid = dap.target.GetProcess().GetProcessID();
   body.try_emplace("systemProcessId", (int64_t)pid);
-  body.try_emplace("isLocalProcess", true);
+  body.try_emplace("isLocalProcess", dap.target.GetPlatform().IsHost());
+  body.try_emplace("pointerSize", dap.target.GetAddressByteSize() * 8);
   const char *startMethod = nullptr;
   switch (launch_method) {
   case Launch:

lldb/tools/lldb-dap/Handler/RestartRequestHandler.cpp

@@ -124,6 +124,8 @@ void RestartRequestHandler::operator()(
     return;
   }
 
+  SendProcessEvent(dap, Launch);
+
   // This is normally done after receiving a "configuration done" request.
   // Because we're restarting, configuration has already happened so we can
   // continue the process right away.