Add option to pass thread ID to thread select command (#73596)

We'd like a way to select the current thread by its thread ID (rather
than its internal LLDB thread index).

This PR adds a `-t` option (`--thread_id` long option) that tells the
`thread select` command to interpret the `<thread-index>` argument as a
thread ID.

Here's an example of it working:
```
michristensen@devbig356 llvm/llvm-project (thread-select-tid) » ../Debug/bin/lldb ~/scratch/cpp/threading/a.out
(lldb) target create "/home/michristensen/scratch/cpp/threading/a.out"
Current executable set to '/home/michristensen/scratch/cpp/threading/a.out' (x86_64).
(lldb) b 18
Breakpoint 1: where = a.out`main + 80 at main.cpp:18:12, address = 0x0000000000000850
(lldb) run
Process 215715 launched: '/home/michristensen/scratch/cpp/threading/a.out' (x86_64)
This is a thread, i=1
This is a thread, i=2
This is a thread, i=3
This is a thread, i=4
This is a thread, i=5
Process 215715 stopped
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x0000555555400850 a.out`main at main.cpp:18:12
   15     for (int i = 0; i < 5; i++) {
   16       pthread_create(&thread_ids[i], NULL, foo, NULL);
   17     }
-> 18     for (int i = 0; i < 5; i++) {
   19       pthread_join(thread_ids[i], NULL);
   20     }
   21     return 0;
(lldb) thread select 2
* thread #2, name = 'a.out'
    frame #0: 0x00007ffff68f9918 libc.so.6`__nanosleep + 72
libc.so.6`__nanosleep:
->  0x7ffff68f9918 <+72>: cmpq   $-0x1000, %rax ; imm = 0xF000
    0x7ffff68f991e <+78>: ja     0x7ffff68f9952 ; <+130>
    0x7ffff68f9920 <+80>: movl   %edx, %edi
    0x7ffff68f9922 <+82>: movl   %eax, 0xc(%rsp)
(lldb) thread info
thread #2: tid = 216047, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'

(lldb) thread list
Process 215715 stopped
  thread #1: tid = 215715, 0x0000555555400850 a.out`main at main.cpp:18:12, name = 'a.out', stop reason = breakpoint 1.1
* thread #2: tid = 216047, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'
  thread #3: tid = 216048, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'
  thread #4: tid = 216049, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'
  thread #5: tid = 216050, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'
  thread #6: tid = 216051, 0x00007ffff68f9918 libc.so.6`__nanosleep + 72, name = 'a.out'
(lldb) thread select 215715
error: invalid thread #215715.
(lldb) thread select -t 215715
* thread #1, name = 'a.out', stop reason = breakpoint 1.1
    frame #0: 0x0000555555400850 a.out`main at main.cpp:18:12
   15     for (int i = 0; i < 5; i++) {
   16       pthread_create(&thread_ids[i], NULL, foo, NULL);
   17     }
-> 18     for (int i = 0; i < 5; i++) {
   19       pthread_join(thread_ids[i], NULL);
   20     }
   21     return 0;
(lldb) thread select -t 216051
* thread #6, name = 'a.out'
    frame #0: 0x00007ffff68f9918 libc.so.6`__nanosleep + 72
libc.so.6`__nanosleep:
->  0x7ffff68f9918 <+72>: cmpq   $-0x1000, %rax ; imm = 0xF000
    0x7ffff68f991e <+78>: ja     0x7ffff68f9952 ; <+130>
    0x7ffff68f9920 <+80>: movl   %edx, %edi
    0x7ffff68f9922 <+82>: movl   %eax, 0xc(%rsp)
(lldb) thread select 3
* thread #3, name = 'a.out'
    frame #0: 0x00007ffff68f9918 libc.so.6`__nanosleep + 72
libc.so.6`__nanosleep:
->  0x7ffff68f9918 <+72>: cmpq   $-0x1000, %rax ; imm = 0xF000
    0x7ffff68f991e <+78>: ja     0x7ffff68f9952 ; <+130>
    0x7ffff68f9920 <+80>: movl   %edx, %edi
    0x7ffff68f9922 <+82>: movl   %eax, 0xc(%rsp)
(lldb) thread select -t 216048
* thread #3, name = 'a.out'
    frame #0: 0x00007ffff68f9918 libc.so.6`__nanosleep + 72
libc.so.6`__nanosleep:
->  0x7ffff68f9918 <+72>: cmpq   $-0x1000, %rax ; imm = 0xF000
    0x7ffff68f991e <+78>: ja     0x7ffff68f9952 ; <+130>
    0x7ffff68f9920 <+80>: movl   %edx, %edi
    0x7ffff68f9922 <+82>: movl   %eax, 0xc(%rsp)
(lldb) thread select --thread_id 216048
* thread #3, name = 'a.out'
    frame #0: 0x00007ffff68f9918 libc.so.6`__nanosleep + 72
libc.so.6`__nanosleep:
->  0x7ffff68f9918 <+72>: cmpq   $-0x1000, %rax ; imm = 0xF000
    0x7ffff68f991e <+78>: ja     0x7ffff68f9952 ; <+130>
    0x7ffff68f9920 <+80>: movl   %edx, %edi
    0x7ffff68f9922 <+82>: movl   %eax, 0xc(%rsp)
(lldb) help thread select
Change the currently selected thread.

Syntax: thread select <cmd-options> <thread-index>

Command Options Usage:
  thread select [-t] <thread-index>

       -t ( --thread_id )
            Provide a thread ID instead of a thread index.

     This command takes options and free-form arguments.  If your arguments
     resemble option specifiers (i.e., they start with a - or --), you must use
     ' -- ' between the end of the command options and the beginning of the
     arguments.
(lldb) c
Process 215715 resuming
Process 215715 exited with status = 0 (0x00000000)
```

1 files changed, 81 insertions, 15 deletions

diff --git a/lldb/source/Commands/CommandObjectThread.cpp b/lldb/source/Commands/CommandObjectThread.cpp
index a9f5a4f..dd9fab4 100644
--- a/lldb/source/Commands/CommandObjectThread.cpp
+++ b/lldb/source/Commands/CommandObjectThread.cpp
@@ -1129,11 +1129,51 @@ protected:
 
 // 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,
+                            "Change the currently selected thread.",
+                            "thread select <thread-index> (or -t <thread-id>)",
                             eCommandRequiresProcess | eCommandTryTargetAPILock |
                                 eCommandProcessMustBeLaunched |
                                 eCommandProcessMustBePaused) {
@@ -1143,6 +1183,7 @@ public:
     // 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.
@@ -1150,6 +1191,9 @@ public:
 
     // 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 +1209,59 @@ public:
         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 index #%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 %" PRIu64 ".\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