python-gdb.py supports method-wrapper

Issue #29367: python-gdb.py now supports also method-wrapper (wrapperobject)
objects.

Author: vstinner

Lib/test/test_gdb.py

@@ -3,13 +3,14 @@
 # The code for testing gdb was adapted from similar work in Unladen Swallow's
 # Lib/test/test_jit_gdb.py
 
+import locale
 import os
 import re
 import subprocess
 import sys
 import sysconfig
+import textwrap
 import unittest
-import locale
 
 # Is this Python configured to support threads?
 try:
@@ -847,6 +848,24 @@ def test_pycfunction(self):
                                           )
         self.assertIn('#1 <built-in method gmtime', gdb_output)
 
+    @unittest.skipIf(python_is_optimized(),
+                     "Python was compiled with optimizations")
+    def test_wrapper_call(self):
+        cmd = textwrap.dedent('''
+            class MyList(list):
+                def __init__(self):
+                    super().__init__()   # wrapper_call()
+
+            l = MyList()
+        ''')
+        # Verify with "py-bt":
+        gdb_output = self.get_stack_trace(cmd,
+                                          breakpoint='wrapper_call',
+                                          cmds_after_breakpoint=['py-bt'],
+                                          )
+        self.assertIn("<method-wrapper '__init__' of MyList object at ",
+                      gdb_output)
+
 
 class PyPrintTests(DebuggerTests):
     @unittest.skipIf(python_is_optimized(),

Misc/NEWS

@@ -746,6 +746,9 @@ Build
 Tools/Demos
 -----------
 
+- Issue #29367: python-gdb.py now supports also ``method-wrapper``
+  (``wrapperobject``) objects.
+
 - Issue #28023: Fix python-gdb.py didn't support new dict implementation.
 
 - Issue #15369: The pybench and pystone microbenchmark have been removed from

Tools/gdb/libpython.py

@@ -362,6 +362,7 @@ def subclass_from_type(cls, t):
                     'set' : PySetObjectPtr,
                     'frozenset' : PySetObjectPtr,
                     'builtin_function_or_method' : PyCFunctionObjectPtr,
+                    'method-wrapper': wrapperobject,
                     }
         if tp_name in name_map:
             return name_map[tp_name]
@@ -1330,6 +1331,39 @@ def write_repr(self, out, visited):
         out.write(quote)
 
 
+class wrapperobject(PyObjectPtr):
+    _typename = 'wrapperobject'
+
+    def safe_name(self):
+        try:
+            name = self.field('descr')['d_base']['name'].string()
+            return repr(name)
+        except (NullPyObjectPtr, RuntimeError):
+            return '<unknown name>'
+
+    def safe_tp_name(self):
+        try:
+            return self.field('self')['ob_type']['tp_name'].string()
+        except (NullPyObjectPtr, RuntimeError):
+            return '<unknown tp_name>'
+
+    def safe_self_addresss(self):
+        try:
+            address = long(self.field('self'))
+            return '%#x' % address
+        except (NullPyObjectPtr, RuntimeError):
+            return '<failed to get self address>'
+
+    def proxyval(self, visited):
+        name = self.safe_name()
+        tp_name = self.safe_tp_name()
+        self_address = self.safe_self_addresss()
+        return ("<method-wrapper %s of %s object at %s>"
+                % (name, tp_name, self_address))
+
+    def write_repr(self, out, visited):
+        proxy = self.proxyval(visited)
+        out.write(proxy)
 
 
 def int_from_int(gdbval):
@@ -1364,11 +1398,13 @@ def to_string (self):
 
 def pretty_printer_lookup(gdbval):
     type = gdbval.type.unqualified()
-    if type.code == gdb.TYPE_CODE_PTR:
-        type = type.target().unqualified()
-        t = str(type)
-        if t in ("PyObject", "PyFrameObject", "PyUnicodeObject"):
-            return PyObjectPtrPrinter(gdbval)
+    if type.code != gdb.TYPE_CODE_PTR:
+        return None
+
+    type = type.target().unqualified()
+    t = str(type)
+    if t in ("PyObject", "PyFrameObject", "PyUnicodeObject", "wrapperobject"):
+        return PyObjectPtrPrinter(gdbval)
 
 """
 During development, I've been manually invoking the code in this way:
@@ -1520,6 +1556,13 @@ def is_other_python_frame(self):
             except RuntimeError:
                 return 'PyCFunction invocation (unable to read %s)' % arg_name
 
+        if caller == 'wrapper_call':
+            try:
+                func = frame.read_var('wp')
+                return str(func)
+            except RuntimeError:
+                return '<wrapper_call invocation>'
+
         # This frame isn't worth reporting:
         return False