gdb/python: New InferiorThread.ptid_string attribute

Message ID eba29f55f1a2816bc55db0b1407f894e274f0f9d.1704821556.git.aburgess@redhat.com
State New
Headers
Series gdb/python: New InferiorThread.ptid_string attribute |

Checks

Context Check Description
linaro-tcwg-bot/tcwg_gdb_build--master-aarch64 success Testing passed
linaro-tcwg-bot/tcwg_gdb_build--master-arm success Testing passed
linaro-tcwg-bot/tcwg_gdb_check--master-arm success Testing passed
linaro-tcwg-bot/tcwg_gdb_check--master-aarch64 success Testing passed

Commit Message

Andrew Burgess Jan. 9, 2024, 5:32 p.m. UTC
  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.
---
 gdb/NEWS                                  |  4 ++++
 gdb/doc/python.texi                       |  7 +++++++
 gdb/python/py-infthread.c                 | 20 ++++++++++++++++++++
 gdb/testsuite/gdb.python/py-infthread.exp |  8 ++++++++
 4 files changed, 39 insertions(+)


base-commit: b7a5722ebdd24a0d15d56e96d30a649ea1d7b0ee
  

Comments

Eli Zaretskii Jan. 9, 2024, 6:50 p.m. UTC | #1
> From: Andrew Burgess <aburgess@redhat.com>
> Cc: Andrew Burgess <aburgess@redhat.com>
> Date: Tue,  9 Jan 2024 17:32:44 +0000
> 
> 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.
> ---
>  gdb/NEWS                                  |  4 ++++
>  gdb/doc/python.texi                       |  7 +++++++
>  gdb/python/py-infthread.c                 | 20 ++++++++++++++++++++
>  gdb/testsuite/gdb.python/py-infthread.exp |  8 ++++++++
>  4 files changed, 39 insertions(+)

The documentation parts are okay, thanks.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
  
Tom Tromey Jan. 9, 2024, 7:10 p.m. UTC | #2
>>>>> "Andrew" == Andrew Burgess <aburgess@redhat.com> writes:

Andrew> +  /* Select the correct inferior before calling a target_* function.  */
Andrew> +  scoped_restore_current_thread restore_thread;
Andrew> +  switch_to_inferior_no_thread (thread_obj->thread->inf);
Andrew> +  std::string ptid_str = target_pid_to_str (ptid);

Python-layer code that calls into gdb should normally be wrapped in a
try/catch, because any exception propagation will be catastrophic.

Tom
  

Patch

diff --git a/gdb/NEWS b/gdb/NEWS
index 11cd6c0663e..60e58daa501 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -87,6 +87,10 @@  show remote thread-options-packet
   ** New function gdb.interrupt(), that interrupts GDB as if the user
      typed control-c.
 
+  ** New gdb.InferiorThread.ptid_string attribute.  This read-only
+     attribute contains the string that appears in the 'Target Id'
+     column of the 'info threads' command output.
+
 * Debugger Adapter Protocol changes
 
   ** GDB now emits the "process" event.
diff --git a/gdb/doc/python.texi b/gdb/doc/python.texi
index d74defeec0c..da37348d663 100644
--- a/gdb/doc/python.texi
+++ b/gdb/doc/python.texi
@@ -4084,6 +4084,13 @@ 
 does not  use that identifier.
 @end defvar
 
+@defvar InferiorThread.ptid_string
+This read-only attribute contains a string representing
+@code{InferiorThread.ptid}.  This is the string that @value{GDBN} uses
+in the @samp{Target Id} column in the @kbd{info threads} output
+(@pxref{info_threads,,@samp{info threads}}).
+@end defvar
+
 @defvar InferiorThread.inferior
 The inferior this thread belongs to.  This attribute is represented as
 a @code{gdb.Inferior} object.  This attribute is not writable.
diff --git a/gdb/python/py-infthread.c b/gdb/python/py-infthread.c
index 00d7171de64..7307b9e9da9 100644
--- a/gdb/python/py-infthread.c
+++ b/gdb/python/py-infthread.c
@@ -185,6 +185,23 @@  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;
+
+  /* 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 ());
+}
+
 /* Getter for InferiorThread.inferior -> Inferior.  */
 
 static PyObject *
@@ -388,6 +405,9 @@  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 },
 
diff --git a/gdb/testsuite/gdb.python/py-infthread.exp b/gdb/testsuite/gdb.python/py-infthread.exp
index 0b10ce9ff77..3b07d84143f 100644
--- a/gdb/testsuite/gdb.python/py-infthread.exp
+++ b/gdb/testsuite/gdb.python/py-infthread.exp
@@ -62,6 +62,14 @@  gdb_test "python print ('result = %s' % t0.num)" " = 1" "test InferiorThread.num
 gdb_test "python print ('result = %s' % t0.global_num)" " = 1" "test InferiorThread.global_num"
 gdb_test "python print ('result = %s' % str (t0.ptid))" " = \\(\[0-9\]+, \[0-9\]+, \[0-9\]+\\)" "test InferiorThread.ptid"
 
+# Test the InferiorThread.ptid_string attribute.  We don't test the
+# actual string contents as they vary based on target, but we check
+# that we get back a non-empty string.
+gdb_test "python print(type(t0.ptid_string))" "<class 'str'>" \
+    "check that InferiorThread.ptid_string is a string"
+gdb_test "python print(t0.ptid_string)" ".+" \
+    "check that InferiorThread.ptid_string is non-empty"
+
 gdb_py_test_silent_cmd "python i0 = t0.inferior" "test InferiorThread.inferior" 1
 gdb_test "python print ('result = %s' % i0.num)" " = 1" "test Inferior.num"