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| author | Damien George <damien.p.george@gmail.com> | 2017-04-05 10:50:26 +1000 |
|---|---|---|
| committer | Damien George <damien.p.george@gmail.com> | 2017-04-05 10:50:26 +1000 |
| commit | de9b53695d1bf8d7580e8371e4bc502a29334e6f (patch) | |
| tree | b2a713516bad10df36487498fdfdf88988a1cb85 /py/compile.c | |
| parent | 546ef301a12ccd6015137964637983432c64d11f (diff) | |
| download | micropython-de9b53695d1bf8d7580e8371e4bc502a29334e6f.tar.gz micropython-de9b53695d1bf8d7580e8371e4bc502a29334e6f.zip | |
py: Raise a ValueError if range() step is zero.
Following CPython. Otherwise one gets either an infinite loop (if code is
optimised by the uPy compiler) or possibly a divide-by-zero CPU exception.
Diffstat (limited to 'py/compile.c')
| -rw-r--r-- | py/compile.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/py/compile.c b/py/compile.c index b2811e9585..cf9e5079b0 100644 --- a/py/compile.c +++ b/py/compile.c @@ -1444,8 +1444,9 @@ STATIC void compile_for_stmt(compiler_t *comp, mp_parse_node_struct_t *pns) { pn_range_start = args[0]; pn_range_end = args[1]; pn_range_step = args[2]; - // We need to know sign of step. This is possible only if it's constant - if (!MP_PARSE_NODE_IS_SMALL_INT(pn_range_step)) { + // the step must be a non-zero constant integer to do the optimisation + if (!MP_PARSE_NODE_IS_SMALL_INT(pn_range_step) + || MP_PARSE_NODE_LEAF_SMALL_INT(pn_range_step) == 0) { optimize = false; } } |