[3.6] bpo-30345: Update test_gdb.py and python-gdb.py from master (#1549)

* python-gdb.py supports method-wrapper

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

(cherry picked from commit 6110833)

* Update and enhance python-gdb.py

bpo-29259: Detect PyCFunction is the current frame, not only in the
older frame.

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:
@@ -845,7 +846,24 @@ def test_pycfunction(self):
                                           breakpoint='time_gmtime',
                                           cmds_after_breakpoint=['py-bt-full'],
                                           )
-        self.assertIn('#0 <built-in method gmtime', gdb_output)
+        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()
+
+            id("first break point")
+            l = MyList()
+        ''')
+        # Verify with "py-bt":
+        gdb_output = self.get_stack_trace(cmd,
+                                          cmds_after_breakpoint=['break wrapper_call', 'continue', 'py-bt'])
+        self.assertRegex(gdb_output,
+                         r"<method-wrapper u?'__init__' of MyList object at ")
 
 
 class PyPrintTests(DebuggerTests):

Misc/NEWS

@@ -151,6 +151,12 @@ Documentation
 
 - bpo-26985: Add missing info of code object in inspect documentation.
 
+Tools/Demos
+-----------
+
+- Issue #29367: python-gdb.py now supports also ``method-wrapper``
+  (``wrapperobject``) objects.
+
 Tests
 -----
 

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:
@@ -1497,11 +1533,8 @@ def is_other_python_frame(self):
             return 'Garbage-collecting'
 
         # Detect invocations of PyCFunction instances:
-        older = self.older()
-        if not older:
-            return False
-
-        caller = older._gdbframe.name()
+        frame = self._gdbframe
+        caller = frame.name()
         if not caller:
             return False
 
@@ -1513,18 +1546,25 @@ def is_other_python_frame(self):
             #   "self" is the (PyObject*) of the 'self'
             try:
                 # Use the prettyprinter for the func:
-                func = older._gdbframe.read_var('func')
+                func = frame.read_var('func')
                 return str(func)
             except RuntimeError:
                 return 'PyCFunction invocation (unable to read "func")'
 
         elif caller == '_PyCFunction_FastCallDict':
             try:
-                func = older._gdbframe.read_var('func_obj')
+                func = frame.read_var('func_obj')
                 return str(func)
             except RuntimeError:
                 return 'PyCFunction invocation (unable to read "func_obj")'
 
+        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