gdb/python: Add gdb.InferiorThread.details attribute

This adds a new read-only attribute gdb.InferiorThread.details, this
attribute contains a string, the results of target_extra_thread_info
for the thread, or None, if target_extra_thread_info returns nullptr.

As the string returned by target_extra_thread_info is unstructured,
this attribute is only really useful for echoing straight through to
the user, but, if a user wants to write a command that displays the
same, or a similar 'Thread Id' to the one seen in 'info threads', then
they need access to this string.

Given that the string produced by target_extra_thread_info varies by
target, there's only minimal testing of this attribute, I check that
the attribute can be accessed, and that the return value is either
None, or a string.

1 files changed, 29 insertions, 0 deletions

diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
index e568d8d..66c3efd 100644
--- a/gdb/python/py-infthread.c
+++ b/gdb/python/py-infthread.c
@@ -76,6 +76,32 @@ thpy_get_name (PyObject *self, void *ignore)
   return PyString_FromString (name);
 }
 
+/* Return a string containing target specific additional information about
+   the state of the thread, or None, if there is no such additional
+   information.  */
+
+static PyObject *
+thpy_get_details (PyObject *self, void *ignore)
+{
+  thread_object *thread_obj = (thread_object *) self;
+
+  THPY_REQUIRE_VALID (thread_obj);
+
+  const char *extra_info;
+  try
+    {
+      extra_info = target_extra_thread_info (thread_obj->thread);
+    }
+  catch (const gdb_exception &except)
+    {
+      GDB_PY_HANDLE_EXCEPTION (except);
+    }
+  if (extra_info == nullptr)
+    Py_RETURN_NONE;
+
+  return PyString_FromString (extra_info);
+}
+
 static int
 thpy_set_name (PyObject *self, PyObject *newvalue, void *ignore)
 {
@@ -347,6 +373,9 @@ static gdb_PyGetSetDef thread_object_getset[] =
 {
   { "name", thpy_get_name, thpy_set_name,
     "The name of the thread, as set by the user or the OS.", NULL },
+  { "details", thpy_get_details, NULL,
+    "A target specific string containing extra thread state details.",
+    NULL },
   { "num", thpy_get_num, NULL,
     "Per-inferior number of the thread, as assigned by GDB.", NULL },
   { "global_num", thpy_get_global_num, NULL,