gdb/python: New InferiorThread.ptid_string attribute

This commit adds a new InferiorThread.ptid_string attribute.  This
read-only attribute contains the string returned by target_pid_to_str,
which actually converts a ptid (not pid) to a string.

This is the string that appears (at least in part) in the output of
'info threads' in the 'Target Id' column, but also in the thread
exited message that GDB prints.

Having access to this string from Python is useful for allowing
extensions identify threads in a similar way to how GDB core would
identify the thread.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
Approved-By: Tom Tromey <tom@tromey.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
index 00d7171..632984d 100644
--- a/gdb/python/py-infthread.c
+++ b/gdb/python/py-infthread.c
@@ -185,6 +185,30 @@ thpy_get_ptid (PyObject *self, void *closure)
   return gdbpy_create_ptid_object (thread_obj->thread->ptid);
 }
 
+/* Implement gdb.InferiorThread.ptid_string attribute.  */
+
+static PyObject *
+thpy_get_ptid_string (PyObject *self, void *closure)
+{
+  thread_object *thread_obj = (thread_object *) self;
+  THPY_REQUIRE_VALID (thread_obj);
+  ptid_t ptid = thread_obj->thread->ptid;
+
+  try
+    {
+      /* Select the correct inferior before calling a target_* function.  */
+      scoped_restore_current_thread restore_thread;
+      switch_to_inferior_no_thread (thread_obj->thread->inf);
+      std::string ptid_str = target_pid_to_str (ptid);
+      return PyUnicode_FromString (ptid_str.c_str ());
+    }
+  catch (const gdb_exception &except)
+    {
+      GDB_PY_HANDLE_EXCEPTION (except);
+      return nullptr;
+    }
+}
+
 /* Getter for InferiorThread.inferior -> Inferior.  */
 
 static PyObject *
@@ -388,6 +412,9 @@ static gdb_PyGetSetDef thread_object_getset[] =
     "Global number of the thread, as assigned by GDB.", NULL },
   { "ptid", thpy_get_ptid, NULL, "ID of the thread, as assigned by the OS.",
     NULL },
+  { "ptid_string", thpy_get_ptid_string, nullptr,
+    "A string representing ptid, as used by, for example, 'info threads'.",
+    nullptr },
   { "inferior", thpy_get_inferior, NULL,
     "The Inferior object this thread belongs to.", NULL },