Add option to pass thread ID to thread select command

lldb/source/Commands/CommandObjectThread.cpp

@@ -1129,8 +1129,47 @@ class CommandObjectThreadUntil : public CommandObjectParsed {
 
 // CommandObjectThreadSelect
 
+#define LLDB_OPTIONS_thread_select
+#include "CommandOptions.inc"
+
 class CommandObjectThreadSelect : public CommandObjectParsed {
 public:
+  class OptionGroupThreadSelect : public OptionGroup {
+  public:
+    OptionGroupThreadSelect() { OptionParsingStarting(nullptr); }
+
+    ~OptionGroupThreadSelect() override = default;
+
+    void OptionParsingStarting(ExecutionContext *execution_context) override {
+      m_thread_id = LLDB_INVALID_THREAD_ID;
+    }
+
+    Status SetOptionValue(uint32_t option_idx, llvm::StringRef option_arg,
+                          ExecutionContext *execution_context) override {
+      const int short_option = g_thread_select_options[option_idx].short_option;
+      switch (short_option) {
+      case 't': {
+        if (option_arg.getAsInteger(0, m_thread_id)) {
+          m_thread_id = LLDB_INVALID_THREAD_ID;
+          return Status("Invalid thread ID: '%s'.", option_arg.str().c_str());
+        }
+        break;
+      }
+
+      default:
+        llvm_unreachable("Unimplemented option");
+      }
+
+      return {};
+    }
+
+    llvm::ArrayRef<OptionDefinition> GetDefinitions() override {
+      return llvm::ArrayRef(g_thread_select_options);
+    }
+
+    lldb::tid_t m_thread_id;
+  };
+
   CommandObjectThreadSelect(CommandInterpreter &interpreter)
       : CommandObjectParsed(interpreter, "thread select",
                             "Change the currently selected thread.", nullptr,
@@ -1143,13 +1182,17 @@ class CommandObjectThreadSelect : public CommandObjectParsed {
     // Define the first (and only) variant of this arg.
     thread_idx_arg.arg_type = eArgTypeThreadIndex;
     thread_idx_arg.arg_repetition = eArgRepeatPlain;
+    thread_idx_arg.arg_opt_set_association = LLDB_OPT_SET_1;
 
     // There is only one variant this argument could be; put it into the
     // argument entry.
     arg.push_back(thread_idx_arg);
 
     // Push the data for the first argument into the m_arguments vector.
     m_arguments.push_back(arg);
+
+    m_option_group.Append(&m_options, LLDB_OPT_SET_ALL, LLDB_OPT_SET_2);
+    m_option_group.Finalize();
   }
 
   ~CommandObjectThreadSelect() override = default;
@@ -1165,37 +1208,59 @@ class CommandObjectThreadSelect : public CommandObjectParsed {
         nullptr);
   }
 
+  Options *GetOptions() override { return &m_option_group; }
+
 protected:
   void DoExecute(Args &command, CommandReturnObject &result) override {
     Process *process = m_exe_ctx.GetProcessPtr();
     if (process == nullptr) {
       result.AppendError("no process");
       return;
-    } else if (command.GetArgumentCount() != 1) {
+    } else if (m_options.m_thread_id == LLDB_INVALID_THREAD_ID &&
+               command.GetArgumentCount() != 1) {
       result.AppendErrorWithFormat(
-          "'%s' takes exactly one thread index argument:\nUsage: %s\n",
+          "'%s' takes exactly one thread index argument, or a thread ID "
+          "option:\nUsage: %s\n",
           m_cmd_name.c_str(), m_cmd_syntax.c_str());
       return;
-    }
-
-    uint32_t index_id;
-    if (!llvm::to_integer(command.GetArgumentAtIndex(0), index_id)) {
-      result.AppendErrorWithFormat("Invalid thread index '%s'",
-                                   command.GetArgumentAtIndex(0));
+    } else if (m_options.m_thread_id != LLDB_INVALID_THREAD_ID &&
+               command.GetArgumentCount() != 0) {
+      result.AppendErrorWithFormat("'%s' cannot take both a thread ID option "
+                                   "and a thread index argument:\nUsage: %s\n",
+                                   m_cmd_name.c_str(), m_cmd_syntax.c_str());
       return;
     }
 
-    Thread *new_thread =
-        process->GetThreadList().FindThreadByIndexID(index_id).get();
-    if (new_thread == nullptr) {
-      result.AppendErrorWithFormat("invalid thread #%s.\n",
-                                   command.GetArgumentAtIndex(0));
-      return;
+    Thread *new_thread = nullptr;
+    if (command.GetArgumentCount() == 1) {
+      uint32_t index_id;
+      if (!llvm::to_integer(command.GetArgumentAtIndex(0), index_id)) {
+        result.AppendErrorWithFormat("Invalid thread index '%s'",
+                                     command.GetArgumentAtIndex(0));
+        return;
+      }
+      new_thread = process->GetThreadList().FindThreadByIndexID(index_id).get();
+      if (new_thread == nullptr) {
+        result.AppendErrorWithFormat("Invalid thread #%s.\n",
+                                     command.GetArgumentAtIndex(0));
+        return;
+      }
+    } else {
+      new_thread =
+          process->GetThreadList().FindThreadByID(m_options.m_thread_id).get();
+      if (new_thread == nullptr) {
+        result.AppendErrorWithFormat("Invalid thread ID %lu.\n",
+                                     m_options.m_thread_id);
+        return;
+      }
     }
 
     process->GetThreadList().SetSelectedThreadByID(new_thread->GetID(), true);
     result.SetStatus(eReturnStatusSuccessFinishNoResult);
   }
+
+  OptionGroupThreadSelect m_options;
+  OptionGroupOptions m_option_group;
 };
 
 // CommandObjectThreadList

lldb/source/Commands/Options.td

@@ -1117,6 +1117,11 @@ let Command = "thread plan list" in {
     Desc<"Display thread plans for unreported threads">;
 }
 
+let Command = "thread select" in {
+  def thread_select_thread_id : Option<"thread-id", "t">, Group<2>,
+    Arg<"ThreadID">, Desc<"Provide a thread ID instead of a thread index.">;
+}
+
 let Command = "thread trace dump function calls" in {
   def thread_trace_dump_function_calls_file : Option<"file", "F">, Group<1>,
     Arg<"Filename">,

lldb/test/API/commands/thread/select/TestThreadSelect.py

@@ -12,17 +12,44 @@ def test_invalid_arg(self):
             self, "// break here", lldb.SBFileSpec("main.cpp")
         )
 
-        self.expect(
-            "thread select -1", error=True, startstr="error: Invalid thread index '-1'"
-        )
         self.expect(
             "thread select 0x1ffffffff",
             error=True,
             startstr="error: Invalid thread index '0x1ffffffff'",
         )
+        self.expect(
+            "thread select -t 0x1ffffffff",
+            error=True,
+            startstr="error: Invalid thread ID",
+        )
+        self.expect(
+            "thread select 1 2 3",
+            error=True,
+            startstr="error: 'thread select' takes exactly one thread index argument, or a thread ID option:",
+        )
+        self.expect(
+            "thread select -t 1234 1",
+            error=True,
+            startstr="error: 'thread select' cannot take both a thread ID option and a thread index argument:",
+        )
         # Parses but not a valid thread id.
         self.expect(
             "thread select 0xffffffff",
             error=True,
-            startstr="error: invalid thread #0xffffffff.",
+            startstr="error: Invalid thread #0xffffffff.",
+        )
+        self.expect(
+            "thread select -t 0xffffffff",
+            error=True,
+            startstr="error: Invalid thread ID",
+        )
+
+    def test_thread_select_tid(self):
+        self.build()
+
+        lldbutil.run_to_source_breakpoint(
+            self, "// break here", lldb.SBFileSpec("main.cpp")
+        )
+        self.runCmd(
+            "thread select -t %d" % self.thread().GetThreadID(),
         )