gdb: change thread_info::name to unique_xmalloc_ptr, add helper function

This started out as changing thread_info::name to a unique_xmalloc_ptr.
That showed that almost all users of that field had the same logic to
get a thread's name: use thread_info::name if non-nullptr, else ask the
target.  Factor out this logic in a new thread_name free function.  Make
the field private (rename to m_name) and add some accessors.

Change-Id: Iebdd95f4cd21fbefc505249bd1d05befc466a2fc

1 files changed, 26 insertions, 4 deletions

diff --git a/gdb/gdbthread.h b/gdb/gdbthread.h
index 4b27194..7beccba 100644
--- a/gdb/gdbthread.h
+++ b/gdb/gdbthread.h
@@ -235,7 +235,6 @@ class thread_info : public refcounted_object,
 {
 public:
   explicit thread_info (inferior *inf, ptid_t ptid);
-  ~thread_info ();
 
   bool deletable () const;
 
@@ -286,9 +285,21 @@ public:
   /* The inferior this thread belongs to.  */
   struct inferior *inf;
 
-  /* The name of the thread, as specified by the user.  This is NULL
-     if the thread does not have a user-given name.  */
-  char *name = NULL;
+  /* The user-given name of the thread.
+
+     Returns nullptr if the thread does not have a user-given name.  */
+  const char *name () const
+  {
+    return m_name.get ();
+  }
+
+  /* Set the user-given name of the thread.
+
+     Pass nullptr to clear the name.  */
+  void set_name (gdb::unique_xmalloc_ptr<char> name)
+  {
+    m_name = std::move (name);
+  }
 
   bool executing () const
   { return m_executing; }
@@ -523,6 +534,11 @@ private:
   /* State of inferior thread to restore after GDB is done with an inferior
      call.  See `struct thread_suspend_state'.  */
   thread_suspend_state m_suspend;
+
+  /* The user-given name of the thread.
+
+     Nullptr if the thread does not have a user-given name.  */
+  gdb::unique_xmalloc_ptr<char> m_name;
 };
 
 using thread_info_resumed_with_pending_wait_status_node
@@ -953,4 +969,10 @@ extern void print_selected_thread_frame (struct ui_out *uiout,
    alive anymore.  */
 extern void thread_select (const char *tidstr, class thread_info *thr);
 
+/* Return THREAD's name.
+
+   If THREAD has a user-given name, return it.  Otherwise, query the thread's
+   target to get the name.  May return nullptr.  */
+extern const char *thread_name (thread_info *thread);
+
 #endif /* GDBTHREAD_H */