[lldb] thread index common completion for commands like `thread select/step-over`

1. Added a common completion completing with a list of the threads of the current process;
2. Apply the common completion above to these commands: thread
   continue/info/exception/select/step-in/step-inst/step-inst-over/step-out/step-over/step-script​
3. Correlated test case test_common_completion_thread_index.

Reviewed By: teemperor

Differential Revision: https://reviews.llvm.org/D84088

1 files changed, 19 insertions, 0 deletions

diff --git a/lldb/source/Commands/CommandCompletions.cpp b/lldb/source/Commands/CommandCompletions.cpp
index de0e07e..526efe3 100644
--- a/lldb/source/Commands/CommandCompletions.cpp
+++ b/lldb/source/Commands/CommandCompletions.cpp
@@ -19,6 +19,7 @@
 #include "lldb/Symbol/CompileUnit.h"
 #include "lldb/Symbol/Variable.h"
 #include "lldb/Target/Language.h"
+#include "lldb/Target/Process.h"
 #include "lldb/Target/RegisterContext.h"
 #include "lldb/Target/Thread.h"
 #include "lldb/Utility/FileSpec.h"
@@ -66,6 +67,7 @@ bool CommandCompletions::InvokeCommonCompletionCallbacks(
       {eTypeLanguageCompletion, CommandCompletions::TypeLanguages},
       {eFrameIndexCompletion, CommandCompletions::FrameIndexes},
       {eStopHookIDCompletion, CommandCompletions::StopHookIDs},
+      {eThreadIndexCompletion, CommandCompletions::ThreadIndexes},
       {eNoCompletion, nullptr} // This one has to be last in the list.
   };
 
@@ -678,3 +680,20 @@ void CommandCompletions::StopHookIDs(CommandInterpreter &interpreter,
                                   strm.GetString());
   }
 }
+
+void CommandCompletions::ThreadIndexes(CommandInterpreter &interpreter,
+                                       CompletionRequest &request,
+                                       SearchFilter *searcher) {
+  const ExecutionContext &exe_ctx = interpreter.GetExecutionContext();
+  if (!exe_ctx.HasProcessScope())
+    return;
+
+  ThreadList &threads = exe_ctx.GetProcessPtr()->GetThreadList();
+  lldb::ThreadSP thread_sp;
+  for (uint32_t idx = 0; (thread_sp = threads.GetThreadAtIndex(idx)); ++idx) {
+    StreamString strm;
+    thread_sp->GetStatus(strm, 0, 1, 1, true);
+    request.TryCompleteCurrentArg(std::to_string(thread_sp->GetIndexID()),
+                                  strm.GetString());
+  }
+}