From b95edf676fe426af1fcde2b2cd532d194a49cb27 Mon Sep 17 00:00:00 2001
From: Padraic Fanning <fanninpm@miamioh.edu>
Date: Sat, 2 Oct 2021 16:14:42 -0400
Subject: [PATCH] Add test_compile from CPython 3.8

---
 Lib/test/test_compile.py | 1083 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 1083 insertions(+)
 create mode 100644 Lib/test/test_compile.py

diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
new file mode 100644
index 000000000..566ca27fc
--- /dev/null
+++ b/Lib/test/test_compile.py
@@ -0,0 +1,1083 @@
+import dis
+import math
+import os
+import unittest
+import sys
+import _ast
+import tempfile
+import types
+from test import support
+from test.support import script_helper, FakePath
+
+class TestSpecifics(unittest.TestCase):
+
+    def compile_single(self, source):
+        compile(source, "<single>", "single")
+
+    def assertInvalidSingle(self, source):
+        self.assertRaises(SyntaxError, self.compile_single, source)
+
+    def test_no_ending_newline(self):
+        compile("hi", "<test>", "exec")
+        compile("hi\r", "<test>", "exec")
+
+    def test_empty(self):
+        compile("", "<test>", "exec")
+
+    def test_other_newlines(self):
+        compile("\r\n", "<test>", "exec")
+        compile("\r", "<test>", "exec")
+        compile("hi\r\nstuff\r\ndef f():\n    pass\r", "<test>", "exec")
+        compile("this_is\rreally_old_mac\rdef f():\n    pass", "<test>", "exec")
+
+    def test_debug_assignment(self):
+        # catch assignments to __debug__
+        self.assertRaises(SyntaxError, compile, '__debug__ = 1', '?', 'single')
+        import builtins
+        prev = builtins.__debug__
+        setattr(builtins, '__debug__', 'sure')
+        self.assertEqual(__debug__, prev)
+        setattr(builtins, '__debug__', prev)
+
+    def test_argument_handling(self):
+        # detect duplicate positional and keyword arguments
+        self.assertRaises(SyntaxError, eval, 'lambda a,a:0')
+        self.assertRaises(SyntaxError, eval, 'lambda a,a=1:0')
+        self.assertRaises(SyntaxError, eval, 'lambda a=1,a=1:0')
+        self.assertRaises(SyntaxError, exec, 'def f(a, a): pass')
+        self.assertRaises(SyntaxError, exec, 'def f(a = 0, a = 1): pass')
+        self.assertRaises(SyntaxError, exec, 'def f(a): global a; a = 1')
+
+    def test_syntax_error(self):
+        self.assertRaises(SyntaxError, compile, "1+*3", "filename", "exec")
+
+    def test_none_keyword_arg(self):
+        self.assertRaises(SyntaxError, compile, "f(None=1)", "<string>", "exec")
+
+    def test_duplicate_global_local(self):
+        self.assertRaises(SyntaxError, exec, 'def f(a): global a; a = 1')
+
+    def test_exec_with_general_mapping_for_locals(self):
+
+        class M:
+            "Test mapping interface versus possible calls from eval()."
+            def __getitem__(self, key):
+                if key == 'a':
+                    return 12
+                raise KeyError
+            def __setitem__(self, key, value):
+                self.results = (key, value)
+            def keys(self):
+                return list('xyz')
+
+        m = M()
+        g = globals()
+        exec('z = a', g, m)
+        self.assertEqual(m.results, ('z', 12))
+        try:
+            exec('z = b', g, m)
+        except NameError:
+            pass
+        else:
+            self.fail('Did not detect a KeyError')
+        exec('z = dir()', g, m)
+        self.assertEqual(m.results, ('z', list('xyz')))
+        exec('z = globals()', g, m)
+        self.assertEqual(m.results, ('z', g))
+        exec('z = locals()', g, m)
+        self.assertEqual(m.results, ('z', m))
+        self.assertRaises(TypeError, exec, 'z = b', m)
+
+        class A:
+            "Non-mapping"
+            pass
+        m = A()
+        self.assertRaises(TypeError, exec, 'z = a', g, m)
+
+        # Verify that dict subclasses work as well
+        class D(dict):
+            def __getitem__(self, key):
+                if key == 'a':
+                    return 12
+                return dict.__getitem__(self, key)
+        d = D()
+        exec('z = a', g, d)
+        self.assertEqual(d['z'], 12)
+
+    def test_extended_arg(self):
+        longexpr = 'x = x or ' + '-x' * 2500
+        g = {}
+        code = '''
+def f(x):
+    %s
+    %s
+    %s
+    %s
+    %s
+    %s
+    %s
+    %s
+    %s
+    %s
+    # the expressions above have no effect, x == argument
+    while x:
+        x -= 1
+        # EXTENDED_ARG/JUMP_ABSOLUTE here
+    return x
+''' % ((longexpr,)*10)
+        exec(code, g)
+        self.assertEqual(g['f'](5), 0)
+
+    def test_argument_order(self):
+        self.assertRaises(SyntaxError, exec, 'def f(a=1, b): pass')
+
+    def test_float_literals(self):
+        # testing bad float literals
+        self.assertRaises(SyntaxError, eval, "2e")
+        self.assertRaises(SyntaxError, eval, "2.0e+")
+        self.assertRaises(SyntaxError, eval, "1e-")
+        self.assertRaises(SyntaxError, eval, "3-4e/21")
+
+    def test_indentation(self):
+        # testing compile() of indented block w/o trailing newline"
+        s = """
+if 1:
+    if 2:
+        pass"""
+        compile(s, "<string>", "exec")
+
+    # This test is probably specific to CPython and may not generalize
+    # to other implementations.  We are trying to ensure that when
+    # the first line of code starts after 256, correct line numbers
+    # in tracebacks are still produced.
+    def test_leading_newlines(self):
+        s256 = "".join(["\n"] * 256 + ["spam"])
+        co = compile(s256, 'fn', 'exec')
+        self.assertEqual(co.co_firstlineno, 257)
+        self.assertEqual(co.co_lnotab, bytes())
+
+    def test_literals_with_leading_zeroes(self):
+        for arg in ["077787", "0xj", "0x.", "0e",  "090000000000000",
+                    "080000000000000", "000000000000009", "000000000000008",
+                    "0b42", "0BADCAFE", "0o123456789", "0b1.1", "0o4.2",
+                    "0b101j2", "0o153j2", "0b100e1", "0o777e1", "0777",
+                    "000777", "000000000000007"]:
+            self.assertRaises(SyntaxError, eval, arg)
+
+        self.assertEqual(eval("0xff"), 255)
+        self.assertEqual(eval("0777."), 777)
+        self.assertEqual(eval("0777.0"), 777)
+        self.assertEqual(eval("000000000000000000000000000000000000000000000000000777e0"), 777)
+        self.assertEqual(eval("0777e1"), 7770)
+        self.assertEqual(eval("0e0"), 0)
+        self.assertEqual(eval("0000e-012"), 0)
+        self.assertEqual(eval("09.5"), 9.5)
+        self.assertEqual(eval("0777j"), 777j)
+        self.assertEqual(eval("000"), 0)
+        self.assertEqual(eval("00j"), 0j)
+        self.assertEqual(eval("00.0"), 0)
+        self.assertEqual(eval("0e3"), 0)
+        self.assertEqual(eval("090000000000000."), 90000000000000.)
+        self.assertEqual(eval("090000000000000.0000000000000000000000"), 90000000000000.)
+        self.assertEqual(eval("090000000000000e0"), 90000000000000.)
+        self.assertEqual(eval("090000000000000e-0"), 90000000000000.)
+        self.assertEqual(eval("090000000000000j"), 90000000000000j)
+        self.assertEqual(eval("000000000000008."), 8.)
+        self.assertEqual(eval("000000000000009."), 9.)
+        self.assertEqual(eval("0b101010"), 42)
+        self.assertEqual(eval("-0b000000000010"), -2)
+        self.assertEqual(eval("0o777"), 511)
+        self.assertEqual(eval("-0o0000010"), -8)
+
+    def test_unary_minus(self):
+        # Verify treatment of unary minus on negative numbers SF bug #660455
+        if sys.maxsize == 2147483647:
+            # 32-bit machine
+            all_one_bits = '0xffffffff'
+            self.assertEqual(eval(all_one_bits), 4294967295)
+            self.assertEqual(eval("-" + all_one_bits), -4294967295)
+        elif sys.maxsize == 9223372036854775807:
+            # 64-bit machine
+            all_one_bits = '0xffffffffffffffff'
+            self.assertEqual(eval(all_one_bits), 18446744073709551615)
+            self.assertEqual(eval("-" + all_one_bits), -18446744073709551615)
+        else:
+            self.fail("How many bits *does* this machine have???")
+        # Verify treatment of constant folding on -(sys.maxsize+1)
+        # i.e. -2147483648 on 32 bit platforms.  Should return int.
+        self.assertIsInstance(eval("%s" % (-sys.maxsize - 1)), int)
+        self.assertIsInstance(eval("%s" % (-sys.maxsize - 2)), int)
+
+    if sys.maxsize == 9223372036854775807:
+        def test_32_63_bit_values(self):
+            a = +4294967296  # 1 << 32
+            b = -4294967296  # 1 << 32
+            c = +281474976710656  # 1 << 48
+            d = -281474976710656  # 1 << 48
+            e = +4611686018427387904  # 1 << 62
+            f = -4611686018427387904  # 1 << 62
+            g = +9223372036854775807  # 1 << 63 - 1
+            h = -9223372036854775807  # 1 << 63 - 1
+
+            for variable in self.test_32_63_bit_values.__code__.co_consts:
+                if variable is not None:
+                    self.assertIsInstance(variable, int)
+
+    def test_sequence_unpacking_error(self):
+        # Verify sequence packing/unpacking with "or".  SF bug #757818
+        i,j = (1, -1) or (-1, 1)
+        self.assertEqual(i, 1)
+        self.assertEqual(j, -1)
+
+    def test_none_assignment(self):
+        stmts = [
+            'None = 0',
+            'None += 0',
+            '__builtins__.None = 0',
+            'def None(): pass',
+            'class None: pass',
+            '(a, None) = 0, 0',
+            'for None in range(10): pass',
+            'def f(None): pass',
+            'import None',
+            'import x as None',
+            'from x import None',
+            'from x import y as None'
+        ]
+        for stmt in stmts:
+            stmt += "\n"
+            self.assertRaises(SyntaxError, compile, stmt, 'tmp', 'single')
+            self.assertRaises(SyntaxError, compile, stmt, 'tmp', 'exec')
+
+    def test_import(self):
+        succeed = [
+            'import sys',
+            'import os, sys',
+            'import os as bar',
+            'import os.path as bar',
+            'from __future__ import nested_scopes, generators',
+            'from __future__ import (nested_scopes,\ngenerators)',
+            'from __future__ import (nested_scopes,\ngenerators,)',
+            'from sys import stdin, stderr, stdout',
+            'from sys import (stdin, stderr,\nstdout)',
+            'from sys import (stdin, stderr,\nstdout,)',
+            'from sys import (stdin\n, stderr, stdout)',
+            'from sys import (stdin\n, stderr, stdout,)',
+            'from sys import stdin as si, stdout as so, stderr as se',
+            'from sys import (stdin as si, stdout as so, stderr as se)',
+            'from sys import (stdin as si, stdout as so, stderr as se,)',
+            ]
+        fail = [
+            'import (os, sys)',
+            'import (os), (sys)',
+            'import ((os), (sys))',
+            'import (sys',
+            'import sys)',
+            'import (os,)',
+            'import os As bar',
+            'import os.path a bar',
+            'from sys import stdin As stdout',
+            'from sys import stdin a stdout',
+            'from (sys) import stdin',
+            'from __future__ import (nested_scopes',
+            'from __future__ import nested_scopes)',
+            'from __future__ import nested_scopes,\ngenerators',
+            'from sys import (stdin',
+            'from sys import stdin)',
+            'from sys import stdin, stdout,\nstderr',
+            'from sys import stdin si',
+            'from sys import stdin,',
+            'from sys import (*)',
+            'from sys import (stdin,, stdout, stderr)',
+            'from sys import (stdin, stdout),',
+            ]
+        for stmt in succeed:
+            compile(stmt, 'tmp', 'exec')
+        for stmt in fail:
+            self.assertRaises(SyntaxError, compile, stmt, 'tmp', 'exec')
+
+    def test_for_distinct_code_objects(self):
+        # SF bug 1048870
+        def f():
+            f1 = lambda x=1: x
+            f2 = lambda x=2: x
+            return f1, f2
+        f1, f2 = f()
+        self.assertNotEqual(id(f1.__code__), id(f2.__code__))
+
+    def test_lambda_doc(self):
+        l = lambda: "foo"
+        self.assertIsNone(l.__doc__)
+
+    def test_encoding(self):
+        code = b'# -*- coding: badencoding -*-\npass\n'
+        self.assertRaises(SyntaxError, compile, code, 'tmp', 'exec')
+        code = '# -*- coding: badencoding -*-\n"\xc2\xa4"\n'
+        compile(code, 'tmp', 'exec')
+        self.assertEqual(eval(code), '\xc2\xa4')
+        code = '"\xc2\xa4"\n'
+        self.assertEqual(eval(code), '\xc2\xa4')
+        code = b'"\xc2\xa4"\n'
+        self.assertEqual(eval(code), '\xa4')
+        code = b'# -*- coding: latin1 -*-\n"\xc2\xa4"\n'
+        self.assertEqual(eval(code), '\xc2\xa4')
+        code = b'# -*- coding: utf-8 -*-\n"\xc2\xa4"\n'
+        self.assertEqual(eval(code), '\xa4')
+        code = b'# -*- coding: iso8859-15 -*-\n"\xc2\xa4"\n'
+        self.assertEqual(eval(code), '\xc2\u20ac')
+        code = '"""\\\n# -*- coding: iso8859-15 -*-\n\xc2\xa4"""\n'
+        self.assertEqual(eval(code), '# -*- coding: iso8859-15 -*-\n\xc2\xa4')
+        code = b'"""\\\n# -*- coding: iso8859-15 -*-\n\xc2\xa4"""\n'
+        self.assertEqual(eval(code), '# -*- coding: iso8859-15 -*-\n\xa4')
+
+    def test_subscripts(self):
+        # SF bug 1448804
+        # Class to make testing subscript results easy
+        class str_map(object):
+            def __init__(self):
+                self.data = {}
+            def __getitem__(self, key):
+                return self.data[str(key)]
+            def __setitem__(self, key, value):
+                self.data[str(key)] = value
+            def __delitem__(self, key):
+                del self.data[str(key)]
+            def __contains__(self, key):
+                return str(key) in self.data
+        d = str_map()
+        # Index
+        d[1] = 1
+        self.assertEqual(d[1], 1)
+        d[1] += 1
+        self.assertEqual(d[1], 2)
+        del d[1]
+        self.assertNotIn(1, d)
+        # Tuple of indices
+        d[1, 1] = 1
+        self.assertEqual(d[1, 1], 1)
+        d[1, 1] += 1
+        self.assertEqual(d[1, 1], 2)
+        del d[1, 1]
+        self.assertNotIn((1, 1), d)
+        # Simple slice
+        d[1:2] = 1
+        self.assertEqual(d[1:2], 1)
+        d[1:2] += 1
+        self.assertEqual(d[1:2], 2)
+        del d[1:2]
+        self.assertNotIn(slice(1, 2), d)
+        # Tuple of simple slices
+        d[1:2, 1:2] = 1
+        self.assertEqual(d[1:2, 1:2], 1)
+        d[1:2, 1:2] += 1
+        self.assertEqual(d[1:2, 1:2], 2)
+        del d[1:2, 1:2]
+        self.assertNotIn((slice(1, 2), slice(1, 2)), d)
+        # Extended slice
+        d[1:2:3] = 1
+        self.assertEqual(d[1:2:3], 1)
+        d[1:2:3] += 1
+        self.assertEqual(d[1:2:3], 2)
+        del d[1:2:3]
+        self.assertNotIn(slice(1, 2, 3), d)
+        # Tuple of extended slices
+        d[1:2:3, 1:2:3] = 1
+        self.assertEqual(d[1:2:3, 1:2:3], 1)
+        d[1:2:3, 1:2:3] += 1
+        self.assertEqual(d[1:2:3, 1:2:3], 2)
+        del d[1:2:3, 1:2:3]
+        self.assertNotIn((slice(1, 2, 3), slice(1, 2, 3)), d)
+        # Ellipsis
+        d[...] = 1
+        self.assertEqual(d[...], 1)
+        d[...] += 1
+        self.assertEqual(d[...], 2)
+        del d[...]
+        self.assertNotIn(Ellipsis, d)
+        # Tuple of Ellipses
+        d[..., ...] = 1
+        self.assertEqual(d[..., ...], 1)
+        d[..., ...] += 1
+        self.assertEqual(d[..., ...], 2)
+        del d[..., ...]
+        self.assertNotIn((Ellipsis, Ellipsis), d)
+
+    def test_annotation_limit(self):
+        # more than 255 annotations, should compile ok
+        s = "def f(%s): pass"
+        s %= ', '.join('a%d:%d' % (i,i) for i in range(300))
+        compile(s, '?', 'exec')
+
+    def test_mangling(self):
+        class A:
+            def f():
+                __mangled = 1
+                __not_mangled__ = 2
+                import __mangled_mod
+                import __package__.module
+
+        self.assertIn("_A__mangled", A.f.__code__.co_varnames)
+        self.assertIn("__not_mangled__", A.f.__code__.co_varnames)
+        self.assertIn("_A__mangled_mod", A.f.__code__.co_varnames)
+        self.assertIn("__package__", A.f.__code__.co_varnames)
+
+    def test_compile_ast(self):
+        fname = __file__
+        if fname.lower().endswith('pyc'):
+            fname = fname[:-1]
+        with open(fname, 'r') as f:
+            fcontents = f.read()
+        sample_code = [
+            ['<assign>', 'x = 5'],
+            ['<ifblock>', """if True:\n    pass\n"""],
+            ['<forblock>', """for n in [1, 2, 3]:\n    print(n)\n"""],
+            ['<deffunc>', """def foo():\n    pass\nfoo()\n"""],
+            [fname, fcontents],
+        ]
+
+        for fname, code in sample_code:
+            co1 = compile(code, '%s1' % fname, 'exec')
+            ast = compile(code, '%s2' % fname, 'exec', _ast.PyCF_ONLY_AST)
+            self.assertTrue(type(ast) == _ast.Module)
+            co2 = compile(ast, '%s3' % fname, 'exec')
+            self.assertEqual(co1, co2)
+            # the code object's filename comes from the second compilation step
+            self.assertEqual(co2.co_filename, '%s3' % fname)
+
+        # raise exception when node type doesn't match with compile mode
+        co1 = compile('print(1)', '<string>', 'exec', _ast.PyCF_ONLY_AST)
+        self.assertRaises(TypeError, compile, co1, '<ast>', 'eval')
+
+        # raise exception when node type is no start node
+        self.assertRaises(TypeError, compile, _ast.If(), '<ast>', 'exec')
+
+        # raise exception when node has invalid children
+        ast = _ast.Module()
+        ast.body = [_ast.BoolOp()]
+        self.assertRaises(TypeError, compile, ast, '<ast>', 'exec')
+
+    def test_dict_evaluation_order(self):
+        i = 0
+
+        def f():
+            nonlocal i
+            i += 1
+            return i
+
+        d = {f(): f(), f(): f()}
+        self.assertEqual(d, {1: 2, 3: 4})
+
+    def test_compile_filename(self):
+        for filename in 'file.py', b'file.py':
+            code = compile('pass', filename, 'exec')
+            self.assertEqual(code.co_filename, 'file.py')
+        for filename in bytearray(b'file.py'), memoryview(b'file.py'):
+            with self.assertWarns(DeprecationWarning):
+                code = compile('pass', filename, 'exec')
+            self.assertEqual(code.co_filename, 'file.py')
+        self.assertRaises(TypeError, compile, 'pass', list(b'file.py'), 'exec')
+
+    @support.cpython_only
+    def test_same_filename_used(self):
+        s = """def f(): pass\ndef g(): pass"""
+        c = compile(s, "myfile", "exec")
+        for obj in c.co_consts:
+            if isinstance(obj, types.CodeType):
+                self.assertIs(obj.co_filename, c.co_filename)
+
+    def test_single_statement(self):
+        self.compile_single("1 + 2")
+        self.compile_single("\n1 + 2")
+        self.compile_single("1 + 2\n")
+        self.compile_single("1 + 2\n\n")
+        self.compile_single("1 + 2\t\t\n")
+        self.compile_single("1 + 2\t\t\n        ")
+        self.compile_single("1 + 2 # one plus two")
+        self.compile_single("1; 2")
+        self.compile_single("import sys; sys")
+        self.compile_single("def f():\n   pass")
+        self.compile_single("while False:\n   pass")
+        self.compile_single("if x:\n   f(x)")
+        self.compile_single("if x:\n   f(x)\nelse:\n   g(x)")
+        self.compile_single("class T:\n   pass")
+
+    def test_bad_single_statement(self):
+        self.assertInvalidSingle('1\n2')
+        self.assertInvalidSingle('def f(): pass')
+        self.assertInvalidSingle('a = 13\nb = 187')
+        self.assertInvalidSingle('del x\ndel y')
+        self.assertInvalidSingle('f()\ng()')
+        self.assertInvalidSingle('f()\n# blah\nblah()')
+        self.assertInvalidSingle('f()\nxy # blah\nblah()')
+        self.assertInvalidSingle('x = 5 # comment\nx = 6\n')
+
+    def test_particularly_evil_undecodable(self):
+        # Issue 24022
+        src = b'0000\x00\n00000000000\n\x00\n\x9e\n'
+        with tempfile.TemporaryDirectory() as tmpd:
+            fn = os.path.join(tmpd, "bad.py")
+            with open(fn, "wb") as fp:
+                fp.write(src)
+            res = script_helper.run_python_until_end(fn)[0]
+        self.assertIn(b"Non-UTF-8", res.err)
+
+    def test_yet_more_evil_still_undecodable(self):
+        # Issue #25388
+        src = b"#\x00\n#\xfd\n"
+        with tempfile.TemporaryDirectory() as tmpd:
+            fn = os.path.join(tmpd, "bad.py")
+            with open(fn, "wb") as fp:
+                fp.write(src)
+            res = script_helper.run_python_until_end(fn)[0]
+        self.assertIn(b"Non-UTF-8", res.err)
+
+    @support.cpython_only
+    def test_compiler_recursion_limit(self):
+        # Expected limit is sys.getrecursionlimit() * the scaling factor
+        # in symtable.c (currently 3)
+        # We expect to fail *at* that limit, because we use up some of
+        # the stack depth limit in the test suite code
+        # So we check the expected limit and 75% of that
+        # XXX (ncoghlan): duplicating the scaling factor here is a little
+        # ugly. Perhaps it should be exposed somewhere...
+        fail_depth = sys.getrecursionlimit() * 3
+        success_depth = int(fail_depth * 0.75)
+
+        def check_limit(prefix, repeated):
+            expect_ok = prefix + repeated * success_depth
+            self.compile_single(expect_ok)
+            broken = prefix + repeated * fail_depth
+            details = "Compiling ({!r} + {!r} * {})".format(
+                         prefix, repeated, fail_depth)
+            with self.assertRaises(RecursionError, msg=details):
+                self.compile_single(broken)
+
+        check_limit("a", "()")
+        check_limit("a", ".b")
+        check_limit("a", "[0]")
+        check_limit("a", "*a")
+
+    def test_null_terminated(self):
+        # The source code is null-terminated internally, but bytes-like
+        # objects are accepted, which could be not terminated.
+        with self.assertRaisesRegex(ValueError, "cannot contain null"):
+            compile("123\x00", "<dummy>", "eval")
+        with self.assertRaisesRegex(ValueError, "cannot contain null"):
+            compile(memoryview(b"123\x00"), "<dummy>", "eval")
+        code = compile(memoryview(b"123\x00")[1:-1], "<dummy>", "eval")
+        self.assertEqual(eval(code), 23)
+        code = compile(memoryview(b"1234")[1:-1], "<dummy>", "eval")
+        self.assertEqual(eval(code), 23)
+        code = compile(memoryview(b"$23$")[1:-1], "<dummy>", "eval")
+        self.assertEqual(eval(code), 23)
+
+        # Also test when eval() and exec() do the compilation step
+        self.assertEqual(eval(memoryview(b"1234")[1:-1]), 23)
+        namespace = dict()
+        exec(memoryview(b"ax = 123")[1:-1], namespace)
+        self.assertEqual(namespace['x'], 12)
+
+    def check_constant(self, func, expected):
+        for const in func.__code__.co_consts:
+            if repr(const) == repr(expected):
+                break
+        else:
+            self.fail("unable to find constant %r in %r"
+                      % (expected, func.__code__.co_consts))
+
+    # Merging equal constants is not a strict requirement for the Python
+    # semantics, it's a more an implementation detail.
+    @support.cpython_only
+    def test_merge_constants(self):
+        # Issue #25843: compile() must merge constants which are equal
+        # and have the same type.
+
+        def check_same_constant(const):
+            ns = {}
+            code = "f1, f2 = lambda: %r, lambda: %r" % (const, const)
+            exec(code, ns)
+            f1 = ns['f1']
+            f2 = ns['f2']
+            self.assertIs(f1.__code__, f2.__code__)
+            self.check_constant(f1, const)
+            self.assertEqual(repr(f1()), repr(const))
+
+        check_same_constant(None)
+        check_same_constant(0)
+        check_same_constant(0.0)
+        check_same_constant(b'abc')
+        check_same_constant('abc')
+
+        # Note: "lambda: ..." emits "LOAD_CONST Ellipsis",
+        # whereas "lambda: Ellipsis" emits "LOAD_GLOBAL Ellipsis"
+        f1, f2 = lambda: ..., lambda: ...
+        self.assertIs(f1.__code__, f2.__code__)
+        self.check_constant(f1, Ellipsis)
+        self.assertEqual(repr(f1()), repr(Ellipsis))
+
+        # Merge constants in tuple or frozenset
+        f1, f2 = lambda: "not a name", lambda: ("not a name",)
+        f3 = lambda x: x in {("not a name",)}
+        self.assertIs(f1.__code__.co_consts[1],
+                      f2.__code__.co_consts[1][0])
+        self.assertIs(next(iter(f3.__code__.co_consts[1])),
+                      f2.__code__.co_consts[1])
+
+        # {0} is converted to a constant frozenset({0}) by the peephole
+        # optimizer
+        f1, f2 = lambda x: x in {0}, lambda x: x in {0}
+        self.assertIs(f1.__code__, f2.__code__)
+        self.check_constant(f1, frozenset({0}))
+        self.assertTrue(f1(0))
+
+    # This is a regression test for a CPython specific peephole optimizer
+    # implementation bug present in a few releases.  It's assertion verifies
+    # that peephole optimization was actually done though that isn't an
+    # indication of the bugs presence or not (crashing is).
+    @support.cpython_only
+    def test_peephole_opt_unreachable_code_array_access_in_bounds(self):
+        """Regression test for issue35193 when run under clang msan."""
+        def unused_code_at_end():
+            return 3
+            raise RuntimeError("unreachable")
+        # The above function definition will trigger the out of bounds
+        # bug in the peephole optimizer as it scans opcodes past the
+        # RETURN_VALUE opcode.  This does not always crash an interpreter.
+        # When you build with the clang memory sanitizer it reliably aborts.
+        self.assertEqual(
+            'RETURN_VALUE',
+            list(dis.get_instructions(unused_code_at_end))[-1].opname)
+
+    def test_dont_merge_constants(self):
+        # Issue #25843: compile() must not merge constants which are equal
+        # but have a different type.
+
+        def check_different_constants(const1, const2):
+            ns = {}
+            exec("f1, f2 = lambda: %r, lambda: %r" % (const1, const2), ns)
+            f1 = ns['f1']
+            f2 = ns['f2']
+            self.assertIsNot(f1.__code__, f2.__code__)
+            self.assertNotEqual(f1.__code__, f2.__code__)
+            self.check_constant(f1, const1)
+            self.check_constant(f2, const2)
+            self.assertEqual(repr(f1()), repr(const1))
+            self.assertEqual(repr(f2()), repr(const2))
+
+        check_different_constants(0, 0.0)
+        check_different_constants(+0.0, -0.0)
+        check_different_constants((0,), (0.0,))
+        check_different_constants('a', b'a')
+        check_different_constants(('a',), (b'a',))
+
+        # check_different_constants() cannot be used because repr(-0j) is
+        # '(-0-0j)', but when '(-0-0j)' is evaluated to 0j: we loose the sign.
+        f1, f2 = lambda: +0.0j, lambda: -0.0j
+        self.assertIsNot(f1.__code__, f2.__code__)
+        self.check_constant(f1, +0.0j)
+        self.check_constant(f2, -0.0j)
+        self.assertEqual(repr(f1()), repr(+0.0j))
+        self.assertEqual(repr(f2()), repr(-0.0j))
+
+        # {0} is converted to a constant frozenset({0}) by the peephole
+        # optimizer
+        f1, f2 = lambda x: x in {0}, lambda x: x in {0.0}
+        self.assertIsNot(f1.__code__, f2.__code__)
+        self.check_constant(f1, frozenset({0}))
+        self.check_constant(f2, frozenset({0.0}))
+        self.assertTrue(f1(0))
+        self.assertTrue(f2(0.0))
+
+    def test_path_like_objects(self):
+        # An implicit test for PyUnicode_FSDecoder().
+        compile("42", FakePath("test_compile_pathlike"), "single")
+
+    def test_stack_overflow(self):
+        # bpo-31113: Stack overflow when compile a long sequence of
+        # complex statements.
+        compile("if a: b\n" * 200000, "<dummy>", "exec")
+
+    # Multiple users rely on the fact that CPython does not generate
+    # bytecode for dead code blocks. See bpo-37500 for more context.
+    @support.cpython_only
+    def test_dead_blocks_do_not_generate_bytecode(self):
+        def unused_block_if():
+            if 0:
+                return 42
+
+        def unused_block_while():
+            while 0:
+                return 42
+
+        def unused_block_if_else():
+            if 1:
+                return None
+            else:
+                return 42
+
+        def unused_block_while_else():
+            while 1:
+                return None
+            else:
+                return 42
+
+        funcs = [unused_block_if, unused_block_while,
+                 unused_block_if_else, unused_block_while_else]
+
+        for func in funcs:
+            opcodes = list(dis.get_instructions(func))
+            self.assertEqual(2, len(opcodes))
+            self.assertEqual('LOAD_CONST', opcodes[0].opname)
+            self.assertEqual(None, opcodes[0].argval)
+            self.assertEqual('RETURN_VALUE', opcodes[1].opname)
+
+    def test_false_while_loop(self):
+        def break_in_while():
+            while False:
+                break
+
+        def continue_in_while():
+            while False:
+                continue
+
+        funcs = [break_in_while, continue_in_while]
+
+        # Check that we did not raise but we also don't generate bytecode
+        for func in funcs:
+            opcodes = list(dis.get_instructions(func))
+            self.assertEqual(2, len(opcodes))
+            self.assertEqual('LOAD_CONST', opcodes[0].opname)
+            self.assertEqual(None, opcodes[0].argval)
+            self.assertEqual('RETURN_VALUE', opcodes[1].opname)
+
+class TestExpressionStackSize(unittest.TestCase):
+    # These tests check that the computed stack size for a code object
+    # stays within reasonable bounds (see issue #21523 for an example
+    # dysfunction).
+    N = 100
+
+    def check_stack_size(self, code):
+        # To assert that the alleged stack size is not O(N), we
+        # check that it is smaller than log(N).
+        if isinstance(code, str):
+            code = compile(code, "<foo>", "single")
+        max_size = math.ceil(math.log(len(code.co_code)))
+        self.assertLessEqual(code.co_stacksize, max_size)
+
+    def test_and(self):
+        self.check_stack_size("x and " * self.N + "x")
+
+    def test_or(self):
+        self.check_stack_size("x or " * self.N + "x")
+
+    def test_and_or(self):
+        self.check_stack_size("x and x or " * self.N + "x")
+
+    def test_chained_comparison(self):
+        self.check_stack_size("x < " * self.N + "x")
+
+    def test_if_else(self):
+        self.check_stack_size("x if x else " * self.N + "x")
+
+    def test_binop(self):
+        self.check_stack_size("x + " * self.N + "x")
+
+    def test_func_and(self):
+        code = "def f(x):\n"
+        code += "   x and x\n" * self.N
+        self.check_stack_size(code)
+
+
+class TestStackSizeStability(unittest.TestCase):
+    # Check that repeating certain snippets doesn't increase the stack size
+    # beyond what a single snippet requires.
+
+    def check_stack_size(self, snippet, async_=False):
+        def compile_snippet(i):
+            ns = {}
+            script = """def func():\n""" + i * snippet
+            if async_:
+                script = "async " + script
+            code = compile(script, "<script>", "exec")
+            exec(code, ns, ns)
+            return ns['func'].__code__
+
+        sizes = [compile_snippet(i).co_stacksize for i in range(2, 5)]
+        if len(set(sizes)) != 1:
+            import dis, io
+            out = io.StringIO()
+            dis.dis(compile_snippet(1), file=out)
+            self.fail("stack sizes diverge with # of consecutive snippets: "
+                      "%s\n%s\n%s" % (sizes, snippet, out.getvalue()))
+
+    def test_if(self):
+        snippet = """
+            if x:
+                a
+            """
+        self.check_stack_size(snippet)
+
+    def test_if_else(self):
+        snippet = """
+            if x:
+                a
+            elif y:
+                b
+            else:
+                c
+            """
+        self.check_stack_size(snippet)
+
+    def test_try_except_bare(self):
+        snippet = """
+            try:
+                a
+            except:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_try_except_qualified(self):
+        snippet = """
+            try:
+                a
+            except ImportError:
+                b
+            except:
+                c
+            else:
+                d
+            """
+        self.check_stack_size(snippet)
+
+    def test_try_except_as(self):
+        snippet = """
+            try:
+                a
+            except ImportError as e:
+                b
+            except:
+                c
+            else:
+                d
+            """
+        self.check_stack_size(snippet)
+
+    def test_try_finally(self):
+        snippet = """
+                try:
+                    a
+                finally:
+                    b
+            """
+        self.check_stack_size(snippet)
+
+    def test_with(self):
+        snippet = """
+            with x as y:
+                a
+            """
+        self.check_stack_size(snippet)
+
+    def test_while_else(self):
+        snippet = """
+            while x:
+                a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for(self):
+        snippet = """
+            for x in y:
+                a
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_else(self):
+        snippet = """
+            for x in y:
+                a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_break_continue(self):
+        snippet = """
+            for x in y:
+                if z:
+                    break
+                elif u:
+                    continue
+                else:
+                    a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_break_continue_inside_try_finally_block(self):
+        snippet = """
+            for x in y:
+                try:
+                    if z:
+                        break
+                    elif u:
+                        continue
+                    else:
+                        a
+                finally:
+                    f
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_break_continue_inside_finally_block(self):
+        snippet = """
+            for x in y:
+                try:
+                    t
+                finally:
+                    if z:
+                        break
+                    elif u:
+                        continue
+                    else:
+                        a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_break_continue_inside_except_block(self):
+        snippet = """
+            for x in y:
+                try:
+                    t
+                except:
+                    if z:
+                        break
+                    elif u:
+                        continue
+                    else:
+                        a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_for_break_continue_inside_with_block(self):
+        snippet = """
+            for x in y:
+                with c:
+                    if z:
+                        break
+                    elif u:
+                        continue
+                    else:
+                        a
+            else:
+                b
+            """
+        self.check_stack_size(snippet)
+
+    def test_return_inside_try_finally_block(self):
+        snippet = """
+            try:
+                if z:
+                    return
+                else:
+                    a
+            finally:
+                f
+            """
+        self.check_stack_size(snippet)
+
+    def test_return_inside_finally_block(self):
+        snippet = """
+            try:
+                t
+            finally:
+                if z:
+                    return
+                else:
+                    a
+            """
+        self.check_stack_size(snippet)
+
+    def test_return_inside_except_block(self):
+        snippet = """
+            try:
+                t
+            except:
+                if z:
+                    return
+                else:
+                    a
+            """
+        self.check_stack_size(snippet)
+
+    def test_return_inside_with_block(self):
+        snippet = """
+            with c:
+                if z:
+                    return
+                else:
+                    a
+            """
+        self.check_stack_size(snippet)
+
+    def test_async_with(self):
+        snippet = """
+            async with x as y:
+                a
+            """
+        self.check_stack_size(snippet, async_=True)
+
+    def test_async_for(self):
+        snippet = """
+            async for x in y:
+                a
+            """
+        self.check_stack_size(snippet, async_=True)
+
+    def test_async_for_else(self):
+        snippet = """
+            async for x in y:
+                a
+            else:
+                b
+            """
+        self.check_stack_size(snippet, async_=True)
+
+    def test_for_break_continue_inside_async_with_block(self):
+        snippet = """
+            for x in y:
+                async with c:
+                    if z:
+                        break
+                    elif u:
+                        continue
+                    else:
+                        a
+            else:
+                b
+            """
+        self.check_stack_size(snippet, async_=True)
+
+    def test_return_inside_async_with_block(self):
+        snippet = """
+            async with c:
+                if z:
+                    return
+                else:
+                    a
+            """
+        self.check_stack_size(snippet, async_=True)
+
+
+if __name__ == "__main__":
+    unittest.main()