[lldb-dap] Support thread focused function breakpoint

Summary: This is part of the DACU support. We can allow a adding a new function breakpoint following the current thread. Setting this without a current focused thread will stop for all thread.

Test Plan: Tested with DACU workflow in D60535622 & D61629279

Reviewers: jsamouh, mbucko, #lldb_team

Reviewed By: mbucko

Subscribers: pdepetro, #lldb_team

Differential Revision: https://phabricator.intern.facebook.com/D61959216

Author: kusmour

lldb/tools/lldb-dap/Breakpoint.cpp

@@ -105,3 +105,7 @@ void Breakpoint::SetBreakpoint() {
   if (!m_hit_condition.empty())
     SetHitCondition();
 }
+
+void Breakpoint::SetThreadID(lldb::tid_t tid) {
+  m_bp.SetThreadID(tid);
+}

lldb/tools/lldb-dap/Breakpoint.h

@@ -30,6 +30,7 @@ class Breakpoint : public BreakpointBase {
 
   bool MatchesName(const char *name);
   void SetBreakpoint();
+  void SetThreadID(lldb::tid_t tid);
 
 protected:
   /// The LLDB breakpoint associated wit this source breakpoint.

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

@@ -21,6 +21,7 @@ llvm::Expected<protocol::SetFunctionBreakpointsResponseBody>
 SetFunctionBreakpointsRequestHandler::Run(
     const protocol::SetFunctionBreakpointsArguments &args) const {
   std::vector<protocol::Breakpoint> response_breakpoints;
+  const bool focus_thread = args.focusThread;
 
   // Disable any function breakpoints that aren't in this request.
   // There is no call to remove function breakpoints other than calling this
@@ -35,7 +36,9 @@ SetFunctionBreakpointsRequestHandler::Run(
       it->second.SetBreakpoint();
     else
       it->second.UpdateBreakpoint(fn_bp);
-
+    // LLDB_INVALID_THREAD_ID will set breakpoint for all thread
+    if (focus_thread && dap.focus_tid != LLDB_INVALID_THREAD_ID)
+      it->second.SetThreadID(dap.focus_tid);
     response_breakpoints.push_back(it->second.ToProtocolBreakpoint());
     seen.erase(fn_bp.GetFunctionName());
   }

lldb/tools/lldb-dap/Protocol/ProtocolRequests.h

@@ -648,6 +648,7 @@ llvm::json::Value toJSON(const SetBreakpointsResponseBody &);
 struct SetFunctionBreakpointsArguments {
   /// The function names of the breakpoints.
   std::vector<FunctionBreakpoint> breakpoints;
+  bool focusThread = false;
 };
 bool fromJSON(const llvm::json::Value &, SetFunctionBreakpointsArguments &,
               llvm::json::Path);