[Python-checkins] cpython (2.7): Issue #13628: python-gdb.py is now able to retrieve more frames in the Python

Mon Dec 19 13:58:24 CET 2011

http://hg.python.org/cpython/rev/1cc8e9565339
changeset: 74078:1cc8e9565339
branch: 2.7
parent: 74072:c6d41dd60d2d
user: Victor Stinner <victor.stinner at haypocalc.com>
date: Mon Dec 19 13:59:58 2011 +0100
summary:
 Issue #13628: python-gdb.py is now able to retrieve more frames in the Python
traceback if Python is optimized.
 * delay the lookup of the size_t type, it is not available at startup
 * The second argument of the PyFrameObjectPtr constructor is optional, as
 done in other constructors
 * iter_builtins() and iter_globals() methods of PyFrameObjectPtr returns
 an empty tuple instead of None if Python is optimized
 * Fix py-bt to handle correctly "optimized" frames
 * Frame.get_pyop() tries to get the frame pointer from PyEval_EvalCodeEx()
 if the pointer is optimized out in PyEval_EvalFrameEx()
files:
 Lib/test/test_gdb.py | 39 ++++++++++++++++++++++-------
 Misc/NEWS | 6 ++++
 Tools/gdb/libpython.py | 34 ++++++++++++++++++++------
 3 files changed, 61 insertions(+), 18 deletions(-)

diff --git a/Lib/test/test_gdb.py b/Lib/test/test_gdb.py
--- a/Lib/test/test_gdb.py
+++ b/Lib/test/test_gdb.py
@@ -32,6 +32,14 @@
 if gdbpy_version == '':
 raise unittest.SkipTest("gdb not built with embedded python support")
 
+def python_is_optimized():
+ cflags = sysconfig.get_config_vars()['PY_CFLAGS']
+ final_opt = ""
+ for opt in cflags.split():
+ if opt.startswith('-O'):
+ final_opt = opt
+ return (final_opt and final_opt != '-O0')
+
 def gdb_has_frame_select():
 # Does this build of gdb have gdb.Frame.select ?
 cmd = "--eval-command=python print(dir(gdb.Frame))"
@@ -543,6 +551,8 @@
 re.DOTALL),
 'Unexpected gdb representation: %r\n%s' % (gdb_output, gdb_output))
 
+ at unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 class PyListTests(DebuggerTests):
 def assertListing(self, expected, actual):
 self.assertEndsWith(actual, expected)
@@ -585,6 +595,8 @@
 
 class StackNavigationTests(DebuggerTests):
 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_pyup_command(self):
 'Verify that the "py-up" command works'
 bt = self.get_stack_trace(script=self.get_sample_script(),
@@ -612,6 +624,8 @@
 'Unable to find an older python frame\n')
 
 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_up_then_down(self):
 'Verify "py-up" followed by "py-down"'
 bt = self.get_stack_trace(script=self.get_sample_script(),
@@ -625,6 +639,8 @@
 $''')
 
 class PyBtTests(DebuggerTests):
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_basic_command(self):
 'Verify that the "py-bt" command works'
 bt = self.get_stack_trace(script=self.get_sample_script(),
@@ -636,10 +652,12 @@
 #[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \(a=1, b=2, c=3\)
 bar\(a, b, c\)
 #[0-9]+ Frame 0x[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \(\)
-foo\(1, 2, 3\)
+ foo\(1, 2, 3\)
 ''')
 
 class PyPrintTests(DebuggerTests):
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_basic_command(self):
 'Verify that the "py-print" command works'
 bt = self.get_stack_trace(script=self.get_sample_script(),
@@ -648,18 +666,24 @@
 r".*\nlocal 'args' = \(1, 2, 3\)\n.*")
 
 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_print_after_up(self):
 bt = self.get_stack_trace(script=self.get_sample_script(),
 cmds_after_breakpoint=['py-up', 'py-print c', 'py-print b', 'py-print a'])
 self.assertMultilineMatches(bt,
 r".*\nlocal 'c' = 3\nlocal 'b' = 2\nlocal 'a' = 1\n.*")
 
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_printing_global(self):
 bt = self.get_stack_trace(script=self.get_sample_script(),
 cmds_after_breakpoint=['py-print __name__'])
 self.assertMultilineMatches(bt,
 r".*\nglobal '__name__' = '__main__'\n.*")
 
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_printing_builtin(self):
 bt = self.get_stack_trace(script=self.get_sample_script(),
 cmds_after_breakpoint=['py-print len'])
@@ -667,6 +691,8 @@
 r".*\nbuiltin 'len' = <built-in function len>\n.*")
 
 class PyLocalsTests(DebuggerTests):
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_basic_command(self):
 bt = self.get_stack_trace(script=self.get_sample_script(),
 cmds_after_breakpoint=['py-locals'])
@@ -674,6 +700,8 @@
 r".*\nargs = \(1, 2, 3\)\n.*")
 
 @unittest.skipUnless(HAS_PYUP_PYDOWN, "test requires py-up/py-down commands")
+ @unittest.skipIf(python_is_optimized(),
+ "Python was compiled with optimizations")
 def test_locals_after_up(self):
 bt = self.get_stack_trace(script=self.get_sample_script(),
 cmds_after_breakpoint=['py-up', 'py-locals'])
@@ -681,15 +709,6 @@
 r".*\na = 1\nb = 2\nc = 3\n.*")
 
 def test_main():
- cflags = sysconfig.get_config_vars()['PY_CFLAGS']
- final_opt = ""
- for opt in cflags.split():
- if opt.startswith('-O'):
- final_opt = opt
- if final_opt and final_opt != '-O0':
- raise unittest.SkipTest("Python was built with compiler optimizations, "
- "tests can't reliably succeed")
-
 run_unittest(PrettyPrintTests,
 PyListTests,
 StackNavigationTests,
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -404,6 +404,12 @@
 - Issue #10639: reindent.py no longer converts newlines and will raise
 an error if attempting to convert a file with mixed newlines.
 
+Tools/Demos
+-----------
+
+- Issue #13628: python-gdb.py is now able to retrieve more frames in the Python
+ traceback if Python is optimized.
+
 Tests
 -----
 
diff --git a/Tools/gdb/libpython.py b/Tools/gdb/libpython.py
--- a/Tools/gdb/libpython.py
+++ b/Tools/gdb/libpython.py
@@ -47,7 +47,6 @@
 _type_char_ptr = gdb.lookup_type('char').pointer() # char*
 _type_unsigned_char_ptr = gdb.lookup_type('unsigned char').pointer() # unsigned char*
 _type_void_ptr = gdb.lookup_type('void').pointer() # void*
-_type_size_t = gdb.lookup_type('size_t')
 
 SIZEOF_VOID_P = _type_void_ptr.sizeof
 
@@ -410,11 +409,15 @@
 self.address)
 
 def _PyObject_VAR_SIZE(typeobj, nitems):
+ if _PyObject_VAR_SIZE._type_size_t is None:
+ _PyObject_VAR_SIZE._type_size_t = gdb.lookup_type('size_t')
+
 return ( ( typeobj.field('tp_basicsize') +
 nitems * typeobj.field('tp_itemsize') +
 (SIZEOF_VOID_P - 1)
 ) & ~(SIZEOF_VOID_P - 1)
- ).cast(_type_size_t)
+ ).cast(_PyObject_VAR_SIZE._type_size_t)
+_PyObject_VAR_SIZE._type_size_t = None
 
 class HeapTypeObjectPtr(PyObjectPtr):
 _typename = 'PyObject'
@@ -786,7 +789,7 @@
 class PyFrameObjectPtr(PyObjectPtr):
 _typename = 'PyFrameObject'
 
- def __init__(self, gdbval, cast_to):
+ def __init__(self, gdbval, cast_to=None):
 PyObjectPtr.__init__(self, gdbval, cast_to)
 
 if not self.is_optimized_out():
@@ -820,7 +823,7 @@
 the global variables of this frame
 '''
 if self.is_optimized_out():
- return
+ return ()
 
 pyop_globals = self.pyop_field('f_globals')
 return pyop_globals.iteritems()
@@ -831,7 +834,7 @@
 the builtin variables
 '''
 if self.is_optimized_out():
- return
+ return ()
 
 pyop_builtins = self.pyop_field('f_builtins')
 return pyop_builtins.iteritems()
@@ -1205,7 +1208,20 @@
 def get_pyop(self):
 try:
 f = self._gdbframe.read_var('f')
- return PyFrameObjectPtr.from_pyobject_ptr(f)
+ frame = PyFrameObjectPtr.from_pyobject_ptr(f)
+ if not frame.is_optimized_out():
+ return frame
+ # gdb is unable to get the "f" argument of PyEval_EvalFrameEx()
+ # because it was "optimized out". Try to get "f" from the frame
+ # of the caller, PyEval_EvalCodeEx().
+ orig_frame = frame
+ caller = self._gdbframe.older()
+ if caller:
+ f = caller.read_var('f')
+ frame = PyFrameObjectPtr.from_pyobject_ptr(f)
+ if not frame.is_optimized_out():
+ return frame
+ return orig_frame
 except ValueError:
 return None
 
@@ -1235,7 +1251,9 @@
 pyop = self.get_pyop()
 if pyop:
 sys.stdout.write('#%i %s\n' % (self.get_index(), pyop.get_truncated_repr(MAX_OUTPUT_LEN)))
- sys.stdout.write(pyop.current_line())
+ if not pyop.is_optimized_out():
+ line = pyop.current_line()
+ sys.stdout.write(' %s\n' % line.strip())
 else:
 sys.stdout.write('#%i (unable to read python frame information)\n' % self.get_index())
 else:
@@ -1281,7 +1299,7 @@
 return
 
 pyop = frame.get_pyop()
- if not pyop:
+ if not pyop or pyop.is_optimized_out():
 print 'Unable to read information on python frame'
 return
 
-- 
Repository URL: http://hg.python.org/cpython
