1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
|
import json
import os
import platform
import subprocess
import sys
import sysconfig
import unittest
from test import support
from test.support import import_helper
_testinternalcapi = import_helper.import_module("_testinternalcapi")
if not support.has_subprocess_support:
raise unittest.SkipTest("test requires subprocess support")
def _frame_pointers_expected(machine):
cflags = " ".join(
value for value in (
sysconfig.get_config_var("PY_CORE_CFLAGS"),
sysconfig.get_config_var("CFLAGS"),
)
if value
)
if "no-omit-frame-pointer" in cflags:
return True
if "omit-frame-pointer" in cflags:
return False
if sys.platform == "darwin":
# macOS x86_64/ARM64 always have frame pointer by default.
return True
if sys.platform == "linux":
if machine in {"aarch64", "arm64"}:
# 32-bit Linux is not supported
if sys.maxsize < 2**32:
return None
return True
if machine == "x86_64":
return False
if sys.platform == "win32":
# MSVC ignores /Oy and /Oy- on x64/ARM64.
if machine == "arm64":
# Windows ARM64 guidelines recommend frame pointers (x29) for stack walking.
return True
elif machine == "x86_64":
# Windows x64 uses unwind metadata; frame pointers are not required.
return None
return None
def _build_stack_and_unwind():
import operator
def build_stack(n, unwinder, warming_up_caller=False):
if warming_up_caller:
return
if n == 0:
return unwinder()
warming_up = True
while warming_up:
# Can't branch on JIT state inside JITted code, so compute here.
warming_up = (
hasattr(sys, "_jit")
and sys._jit.is_enabled()
and not sys._jit.is_active()
)
result = operator.call(build_stack, n - 1, unwinder, warming_up)
return result
stack = build_stack(10, _testinternalcapi.manual_frame_pointer_unwind)
return stack
def _classify_stack(stack, jit_enabled):
labels = _testinternalcapi.classify_stack_addresses(stack, jit_enabled)
annotated = []
jit_frames = 0
python_frames = 0
other_frames = 0
for idx, (frame, tag) in enumerate(zip(stack, labels)):
addr = int(frame)
if tag == "jit":
jit_frames += 1
elif tag == "python":
python_frames += 1
else:
other_frames += 1
annotated.append((idx, addr, tag))
return annotated, python_frames, jit_frames, other_frames
def _annotate_unwind():
stack = _build_stack_and_unwind()
jit_enabled = hasattr(sys, "_jit") and sys._jit.is_enabled()
jit_backend = _testinternalcapi.get_jit_backend()
ranges = _testinternalcapi.get_jit_code_ranges() if jit_enabled else []
if jit_enabled and ranges:
print("JIT ranges:")
for start, end in ranges:
print(f" {int(start):#x}-{int(end):#x}")
annotated, python_frames, jit_frames, other_frames = _classify_stack(
stack, jit_enabled
)
for idx, addr, tag in annotated:
print(f"#{idx:02d} {addr:#x} -> {tag}")
return json.dumps({
"length": len(stack),
"python_frames": python_frames,
"jit_frames": jit_frames,
"other_frames": other_frames,
"jit_backend": jit_backend,
})
def _manual_unwind_length(**env):
code = (
"from test.test_frame_pointer_unwind import _annotate_unwind; "
"print(_annotate_unwind());"
)
run_env = os.environ.copy()
run_env.update(env)
proc = subprocess.run(
[sys.executable, "-c", code],
env=run_env,
capture_output=True,
text=True,
)
# Surface the output for debugging/visibility when running this test
if proc.stdout:
print(proc.stdout, end="")
if proc.returncode:
raise RuntimeError(
f"unwind helper failed (rc={proc.returncode}): {proc.stderr or proc.stdout}"
)
stdout_lines = proc.stdout.strip().splitlines()
if not stdout_lines:
raise RuntimeError("unwind helper produced no output")
try:
return json.loads(stdout_lines[-1])
except ValueError as exc:
raise RuntimeError(
f"unexpected output from unwind helper: {proc.stdout!r}"
) from exc
@support.requires_gil_enabled("test requires the GIL enabled")
@unittest.skipIf(support.is_wasi, "test not supported on WASI")
class FramePointerUnwindTests(unittest.TestCase):
def setUp(self):
super().setUp()
machine = platform.machine().lower()
expected = _frame_pointers_expected(machine)
if expected is None:
self.skipTest(f"unsupported architecture for frame pointer check: {machine}")
try:
_testinternalcapi.manual_frame_pointer_unwind()
except RuntimeError as exc:
if "not supported" in str(exc):
self.skipTest("manual frame pointer unwinding not supported on this platform")
raise
self.machine = machine
self.frame_pointers_expected = expected
def test_manual_unwind_respects_frame_pointers(self):
jit_available = hasattr(sys, "_jit") and sys._jit.is_available()
envs = [({"PYTHON_JIT": "0"}, False)]
if jit_available:
envs.append(({"PYTHON_JIT": "1"}, True))
for env, using_jit in envs:
with self.subTest(env=env):
result = _manual_unwind_length(**env)
jit_frames = result["jit_frames"]
python_frames = result.get("python_frames", 0)
jit_backend = result.get("jit_backend")
if self.frame_pointers_expected:
self.assertGreater(
python_frames,
0,
f"expected to find Python frames on {self.machine} with env {env}",
)
if using_jit:
if jit_backend == "jit":
self.assertGreater(
jit_frames,
0,
f"expected to find JIT frames on {self.machine} with env {env}",
)
else:
# jit_backend is "interpreter" or not present
self.assertEqual(
jit_frames,
0,
f"unexpected JIT frames counted on {self.machine} with env {env}",
)
else:
self.assertEqual(
jit_frames,
0,
f"unexpected JIT frames counted on {self.machine} with env {env}",
)
else:
self.assertLessEqual(
python_frames,
1,
f"unexpected Python frames counted on {self.machine} with env {env}",
)
self.assertEqual(
jit_frames,
0,
f"unexpected JIT frames counted on {self.machine} with env {env}",
)
if __name__ == "__main__":
unittest.main()
|
