Add stack overflow checking to Python

third_party/python/Include/ceval.h

@@ -1,6 +1,8 @@
 #ifndef Py_CEVAL_H
 #define Py_CEVAL_H
+#include "libc/bits/likely.h"
 #include "third_party/python/Include/object.h"
+#include "third_party/python/Include/pyerrors.h"
 #include "third_party/python/Include/pystate.h"
 #include "third_party/python/Include/pythonrun.h"
 COSMOPOLITAN_C_START_
@@ -77,18 +79,24 @@ int Py_MakePendingCalls(void);
 void Py_SetRecursionLimit(int);
 int Py_GetRecursionLimit(void);
 
-#if IsModeDbg()
+forceinline int Py_EnterRecursiveCall(const char *where) {
-#define Py_EnterRecursiveCall(where)  \
+  const char *rsp, *bot;
-            (_Py_MakeRecCheck(PyThreadState_GET()->recursion_depth) &&  \
+  extern char ape_stack_vaddr[] __attribute__((__weak__));
-             _Py_CheckRecursiveCall(where))
+  if (!IsTiny()) {
-#define Py_LeaveRecursiveCall()                         \
+    rsp = __builtin_frame_address(0);
-    do{ if(_Py_MakeEndRecCheck(PyThreadState_GET()->recursion_depth))  \
+    asm(".weak\tape_stack_vaddr\n\t"
-      PyThreadState_GET()->overflowed = 0;  \
+        "movabs\t$ape_stack_vaddr+12288,%0" : "=r"(bot));
-    } while(0)
+    if (UNLIKELY(rsp < bot)) {
-#else
+      PyErr_Format(PyExc_MemoryError, "Stack overflow%s", where);
-#define Py_EnterRecursiveCall(where) (0)
+      return -1;
-#define Py_LeaveRecursiveCall(where) ((void)0)
+    }
-#endif
+  }
+  return 0;
+}
+
+forceinline void Py_LeaveRecursiveCall(void) {
+}
+
 int _Py_CheckRecursiveCall(const char *where);
 extern int _Py_CheckRecursionLimit;
 

third_party/python/Lib/test/test_class.py

@@ -490,8 +490,6 @@ class ClassTests(unittest.TestCase):
 
         self.assertRaises(TypeError, hash, C2())
 
-
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def testSFBug532646(self):
         # Test for SF bug 532646
 
@@ -502,7 +500,7 @@ class ClassTests(unittest.TestCase):
 
         try:
             a() # This should not segfault
-        except RecursionError:
+        except (RecursionError, MemoryError):
             pass
         else:
             self.fail("Failed to raise RecursionError")

third_party/python/Lib/test/test_descr.py

@@ -3470,16 +3470,14 @@ order (MRO) for bases """
         list.__init__(a, sequence=[0, 1, 2])
         self.assertEqual(a, [0, 1, 2])
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursive_call(self):
         # Testing recursive __call__() by setting to instance of class...
         class A(object):
             pass
-
         A.__call__ = A()
         try:
             A()()
-        except RecursionError:
+        except (RecursionError, MemoryError):
             pass
         else:
             self.fail("Recursion limit should have been reached for __call__()")
@@ -4496,7 +4494,6 @@ order (MRO) for bases """
         with self.assertRaises(TypeError):
             str.__add__(fake_str, "abc")
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_repr_as_str(self):
         # Issue #11603: crash or infinite loop when rebinding __str__ as
         # __repr__.
@@ -4504,8 +4501,12 @@ order (MRO) for bases """
             pass
         Foo.__repr__ = Foo.__str__
         foo = Foo()
-        self.assertRaises(RecursionError, str, foo)
+        if cosmo.MODE == 'dbg':
-        self.assertRaises(RecursionError, repr, foo)
+            self.assertRaises(RecursionError, str, foo)
+            self.assertRaises(RecursionError, repr, foo)
+        else:
+            self.assertRaises(MemoryError, str, foo)
+            self.assertRaises(MemoryError, repr, foo)
 
     def test_mixing_slot_wrappers(self):
         class X(dict):

third_party/python/Lib/test/test_dictviews.py

@@ -219,7 +219,12 @@ class DictSetTest(unittest.TestCase):
         d = {}
         for i in range(sys.getrecursionlimit() + 100):
             d = {42: d.values()}
-        self.assertRaises(RecursionError, repr, d)
+        try:
+            repr(d)
+        except (RecursionError, MemoryError):
+            pass
+        else:
+            assert False
 
     def test_copy(self):
         d = {1: 10, "a": "ABC"}

third_party/python/Lib/test/test_exceptions.py

@@ -515,12 +515,11 @@ class ExceptionTests(unittest.TestCase):
         self.assertEqual(x.fancy_arg, 42)
 
     @no_tracing
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
+    @unittest.skipUnless(cosmo.MODE == "dbg", "TODO: disabled recursion checking")
     def testInfiniteRecursion(self):
         def f():
             return f()
         self.assertRaises(RecursionError, f)
-
         def g():
             try:
                 return g()
@@ -939,8 +938,8 @@ class ExceptionTests(unittest.TestCase):
             self.assertTrue(isinstance(v, RecursionError), type(v))
             self.assertIn("maximum recursion depth exceeded", str(v))
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     @cpython_only
+    @unittest.skipUnless(cosmo.MODE == "dbg", "TODO: disabled recursion checking")
     def test_recursion_normalizing_exception(self):
         # Issue #22898.
         # Test that a RecursionError is raised when tstate->recursion_depth is
@@ -1017,8 +1016,8 @@ class ExceptionTests(unittest.TestCase):
                       b'while normalizing an exception', err)
         self.assertIn(b'Done.', out)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     @cpython_only
+    @unittest.skipUnless(cosmo.MODE == "dbg", "TODO: disabled recursion checking")
     def test_recursion_normalizing_with_no_memory(self):
         # Issue #30697. Test that in the abort that occurs when there is no
         # memory left and the size of the Python frames stack is greater than
@@ -1123,7 +1122,8 @@ class ExceptionTests(unittest.TestCase):
         self.assertEqual(wr(), None)
 
     @no_tracing
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
+    @unittest.skipIf(cosmo.MODE != 'dbg',
+                     "WUT: Fatal Python error: Cannot recover from MemoryErrors while normalizing exceptions.")
     def test_recursion_error_cleanup(self):
         # Same test as above, but with "recursion exceeded" errors
         class C:

third_party/python/Lib/test/test_fileio.py

@@ -177,12 +177,16 @@ class AutoFileTests:
         finally:
             os.close(fd)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
+    # @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def testRecursiveRepr(self):
         # Issue #25455
         with swap_attr(self.f, 'name', self.f):
-            with self.assertRaises(RuntimeError):
+            try:
                 repr(self.f)  # Should not crash
+            except (RuntimeError, MemoryError):
+                pass
+            else:
+                assert False
 
     def testErrors(self):
         f = self.f

third_party/python/Lib/test/test_functools.py

@@ -217,7 +217,6 @@ class TestPartial:
                       [f'{name}({capture!r}, {args_repr}, {kwargs_repr})'
                        for kwargs_repr in kwargs_reprs])
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursive_repr(self):
         if self.partial in (c_functools.partial, py_functools.partial):
             name = 'functools.partial'

third_party/python/Lib/test/test_io.py

@@ -1100,7 +1100,6 @@ class CommonBufferedTests:
         raw.name = b"dummy"
         self.assertEqual(repr(b), "<%s name=b'dummy'>" % clsname)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursive_repr(self):
         # Issue #25455
         raw = self.MockRawIO()
@@ -2542,7 +2541,6 @@ class TextIOWrapperTest(unittest.TestCase):
         t.buffer.detach()
         repr(t)  # Should not raise an exception
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursive_repr(self):
         # Issue #25455
         raw = self.BytesIO()

third_party/python/Lib/test/test_json/test_recursion.py

@@ -67,7 +67,6 @@ class TestRecursion:
             self.fail("didn't raise ValueError on default recursion")
 
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_highly_nested_objects_decoding(self):
         # test that loading highly-nested objects doesn't segfault when C
         # accelerations are used. See #12017
@@ -78,7 +77,6 @@ class TestRecursion:
         with self.assertRaises(RecursionError):
             self.loads('[' * 100000 + '1' + ']' * 100000)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_highly_nested_objects_encoding(self):
         # See #12051
         l, d = [], {}
@@ -89,7 +87,6 @@ class TestRecursion:
         with self.assertRaises(RecursionError):
             self.dumps(d)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_endless_recursion(self):
         # See #12051
         class EndlessJSONEncoder(self.json.JSONEncoder):

third_party/python/Lib/test/test_plistlib.py

@@ -814,13 +814,12 @@ class TestBinaryPlistlib(unittest.TestCase):
         b = plistlib.loads(plistlib.dumps(a, fmt=plistlib.FMT_BINARY))
         self.assertIs(b['x'], b)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_deep_nesting(self):
         for N in [300, 100000]:
             chunks = [b'\xa1' + (i + 1).to_bytes(4, 'big') for i in range(N)]
             try:
                 result = self.decode(*chunks, b'\x54seed', offset_size=4, ref_size=4)
-            except RecursionError:
+            except (RecursionError, MemoryError):
                 pass
             else:
                 for i in range(N):

third_party/python/Lib/test/test_richcmp.py

@@ -221,7 +221,7 @@ class MiscTest(unittest.TestCase):
         for func in (do, operator.not_):
             self.assertRaises(Exc, func, Bad())
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
+    @unittest.skipUnless(cosmo.MODE == "dbg", "TODO: disabled recursion checking")
     @support.no_tracing
     def test_recursion(self):
         # Check that comparison for recursive objects fails gracefully

third_party/python/Lib/test/test_runpy.py

@@ -724,7 +724,6 @@ class RunPathTestCase(unittest.TestCase, CodeExecutionMixin):
             self._check_import_error(zip_name, msg)
 
     @no_tracing
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_main_recursion_error(self):
         with temp_dir() as script_dir, temp_dir() as dummy_dir:
             mod_name = '__main__'

third_party/python/Lib/test/test_sys.py

@@ -191,7 +191,6 @@ class SysModuleTest(unittest.TestCase):
         finally:
             sys.setswitchinterval(orig)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursionlimit(self):
         self.assertRaises(TypeError, sys.getrecursionlimit, 42)
         oldlimit = sys.getrecursionlimit()
@@ -201,7 +200,6 @@ class SysModuleTest(unittest.TestCase):
         self.assertEqual(sys.getrecursionlimit(), 10000)
         sys.setrecursionlimit(oldlimit)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursionlimit_recovery(self):
         if hasattr(sys, 'gettrace') and sys.gettrace():
             self.skipTest('fatal error if run with a trace function')
@@ -225,7 +223,6 @@ class SysModuleTest(unittest.TestCase):
         finally:
             sys.setrecursionlimit(oldlimit)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     @test.support.cpython_only
     def test_setrecursionlimit_recursion_depth(self):
         # Issue #25274: Setting a low recursion limit must be blocked if the
@@ -261,7 +258,6 @@ class SysModuleTest(unittest.TestCase):
         finally:
             sys.setrecursionlimit(oldlimit)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursionlimit_fatalerror(self):
         # A fatal error occurs if a second recursion limit is hit when recovering
         # from a first one.

third_party/python/Lib/test/test_threading.py

@@ -883,7 +883,6 @@ class ThreadingExceptionTests(BaseTestCase):
         lock = threading.Lock()
         self.assertRaises(RuntimeError, lock.release)
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     @unittest.skipUnless(sys.platform == 'darwin' and test.support.python_is_optimized(),
                          'test macosx problem')
     def test_recursion_limit(self):

third_party/python/Lib/test/test_traceback.py

@@ -301,7 +301,6 @@ class TracebackFormatTests(unittest.TestCase):
         ])
 
     # issue 26823 - Shrink recursive tracebacks
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def _check_recursive_traceback_display(self, render_exc):
         # Always show full diffs when this test fails
         # Note that rearranging things may require adjusting

third_party/python/Lib/test/test_xml_etree.py

@@ -1921,7 +1921,6 @@ class BadElementTest(ElementTestCase, unittest.TestCase):
         e.extend([ET.Element('bar')])
         self.assertRaises(ValueError, e.remove, X('baz'))
 
-    @unittest.skipUnless(cosmo.MODE == "dbg", "disabled recursion checking")
     def test_recursive_repr(self):
         # Issue #25455
         e = ET.Element('foo')