11import dis
22import unittest
3+ import types
4+ import textwrap
35
46from test .bytecode_helper import BytecodeTestCase
57
@@ -18,6 +20,27 @@ def count_instr_recursively(f, opname):
1820
1921class TestTranforms (BytecodeTestCase ):
2022
23+ def check_jump_targets (self ,code ):
24+ instructions = list (dis .get_instructions (code ))
25+ targets = {instr .offset :instr for instr in instructions }
26+ for instr in instructions :
27+ if 'JUMP_' not in instr .opname :
28+ continue
29+ tgt = targets [instr .argval ]
30+ # jump to unconditional jump
31+ if tgt .opname in ('JUMP_ABSOLUTE' ,'JUMP_FORWARD' ):
32+ self .fail (f'{ instr .opname } { instr .offset }
33+ f'jumps to{ tgt .opname } { tgt .offset } )
34+ # unconditional jump to RETURN_VALUE
35+ if (instr .opname in ('JUMP_ABSOLUTE' ,'JUMP_FORWARD' )and
36+ tgt .opname == 'RETURN_VALUE' ):
37+ self .fail (f'{ instr .opname } { instr .offset }
38+ f'jumps to{ tgt .opname } { tgt .offset } )
39+ # JUMP_IF_*_OR_POP jump to conditional jump
40+ if '_OR_POP' in instr .opname and 'JUMP_IF_' in tgt .opname :
41+ self .fail (f'{ instr .opname } { instr .offset }
42+ f'jumps to{ tgt .opname } { tgt .offset } )
43+
2144def test_unot (self ):
2245# UNARY_NOT POP_JUMP_IF_FALSE --> POP_JUMP_IF_TRUE'
2346def unot (x ):
@@ -259,13 +282,69 @@ def f(x):
259282def test_elim_jump_to_return (self ):
260283# JUMP_FORWARD to RETURN --> RETURN
261284def f (cond ,true_value ,false_value ):
262- return true_value if cond else false_value
285+ # Intentionally use two-line expression to test issue37213.
286+ return (true_value if cond
287+ else false_value )
288+ self .check_jump_targets (f )
263289self .assertNotInBytecode (f ,'JUMP_FORWARD' )
264290self .assertNotInBytecode (f ,'JUMP_ABSOLUTE' )
265291returns = [instr for instr in dis .get_instructions (f )
266292if instr .opname == 'RETURN_VALUE' ]
267293self .assertEqual (len (returns ),2 )
268294
295+ def test_elim_jump_to_uncond_jump (self ):
296+ # POP_JUMP_IF_FALSE to JUMP_FORWARD --> POP_JUMP_IF_FALSE to non-jump
297+ def f ():
298+ if a :
299+ # Intentionally use two-line expression to test issue37213.
300+ if (c
301+ or d ):
302+ foo ()
303+ else :
304+ baz ()
305+ self .check_jump_targets (f )
306+
307+ def test_elim_jump_to_uncond_jump2 (self ):
308+ # POP_JUMP_IF_FALSE to JUMP_ABSOLUTE --> POP_JUMP_IF_FALSE to non-jump
309+ def f ():
310+ while a :
311+ # Intentionally use two-line expression to test issue37213.
312+ if (c
313+ or d ):
314+ a = foo ()
315+ self .check_jump_targets (f )
316+
317+ def test_elim_jump_to_uncond_jump3 (self ):
318+ # Intentionally use two-line expressions to test issue37213.
319+ # JUMP_IF_FALSE_OR_POP to JUMP_IF_FALSE_OR_POP --> JUMP_IF_FALSE_OR_POP to non-jump
320+ def f (a ,b ,c ):
321+ return ((a and b )
322+ and c )
323+ self .check_jump_targets (f )
324+ self .assertEqual (count_instr_recursively (f ,'JUMP_IF_FALSE_OR_POP' ),2 )
325+ # JUMP_IF_TRUE_OR_POP to JUMP_IF_TRUE_OR_POP --> JUMP_IF_TRUE_OR_POP to non-jump
326+ def f (a ,b ,c ):
327+ return ((a or b )
328+ or c )
329+ self .check_jump_targets (f )
330+ self .assertEqual (count_instr_recursively (f ,'JUMP_IF_TRUE_OR_POP' ),2 )
331+ # JUMP_IF_FALSE_OR_POP to JUMP_IF_TRUE_OR_POP --> POP_JUMP_IF_FALSE to non-jump
332+ def f (a ,b ,c ):
333+ return ((a and b )
334+ or c )
335+ self .check_jump_targets (f )
336+ self .assertNotInBytecode (f ,'JUMP_IF_FALSE_OR_POP' )
337+ self .assertInBytecode (f ,'JUMP_IF_TRUE_OR_POP' )
338+ self .assertInBytecode (f ,'POP_JUMP_IF_FALSE' )
339+ # JUMP_IF_TRUE_OR_POP to JUMP_IF_FALSE_OR_POP --> POP_JUMP_IF_TRUE to non-jump
340+ def f (a ,b ,c ):
341+ return ((a or b )
342+ and c )
343+ self .check_jump_targets (f )
344+ self .assertNotInBytecode (f ,'JUMP_IF_TRUE_OR_POP' )
345+ self .assertInBytecode (f ,'JUMP_IF_FALSE_OR_POP' )
346+ self .assertInBytecode (f ,'POP_JUMP_IF_TRUE' )
347+
269348def test_elim_jump_after_return1 (self ):
270349# Eliminate dead code: jumps immediately after returns can't be reached
271350def f (cond1 ,cond2 ):