[issue26204] compiler: don't emit LOAD_CONST instructions for constant statements?

[STINNER Victor]

STINNER Victor added the comment:

"""
Will the following code compile OK?  What will it compile to?

   if 1:
      42
"""

compile OK: what do you mean? This code doesn't make any sense to me :-)


Currently text strings statements are ignored:
---
>>> def f():
...  if 1:
...   "abc"
... 
>>> import dis
>>> dis.dis(f)
  3           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE
---


But byte strings emit a LOAD_CONST+POP_TOP:
---
>>> def g():
...  if 1:
...   b'bytes'
... 
>>> dis.dis(g)
  3           0 LOAD_CONST               1 (b'bytes')
              3 POP_TOP
              4 LOAD_CONST               0 (None)
              7 RETURN_VALUE
---


With my patch, all constants statements will be ignored. Example with my patch:
---
>>> def h():
...  if 1:
...   b'bytes'
... 
>>> import dis; dis.dis(h)
  3           0 LOAD_CONST               0 (None)
              3 RETURN_VALUE
---

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue26204>
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