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4010 :: Diferent results when compiled with c (gcc), or cpp (gcc)

[2018-07-03T19:44:05+02:00]

ErikCampobadal (orginal) [2018-07-03T19:44:05+02:00] view original
Cleared nimcache, still doing the same

Good one:
- C: http://prntscr.com/k24pyz
Bad ones:
- CPP: http://prntscr.com/k24poz
Can't try JS because it says OS is not ported to my OS (windows).

Is this even supposed to happen?

code hosted here: https://github.com/ConsoleTVs/TFG/tree/master/void

Seems like the bytecode output is correct in both codes. The error relies in the vm.nim and derivates for sure...

ErikCampobadal (orginal) [2018-07-03T20:19:49+02:00] view original

Hints to devs: The answer is about how arguments are passed to functions.

CPP: http://prntscr.com/k255u4 & http://prntscr.com/k255zk CPP FIXED: http://prntscr.com/k256fv & http://prntscr.com/k256le

A feature like this SHOULD not change how it works between backends.

This is a serious issue. I'll post it on github issues.

ErikCampobadal (orginal) [2018-07-03T20:25:49+02:00] view original

This commit fixed the issue for me: https://github.com/ConsoleTVs/TFG/commit/c3698f64a08adf4dc5bb19579e56ff180009ba1a#diff-ecd2a08316dc75e0142a9547a218c408

Araq (orginal) [2018-07-03T21:13:11+02:00] view original

We cannot introduce temporaries in the C++ backend that easily to enforce left-to-right order of evaluation because a C++ type might have a private assignment operator. Newer C++ versions with move semantics mitigate this problem.

treeform (orginal) [2018-07-03T23:13:44+02:00] view original

I have run into this problem before too. Both C and C++ can exhibit this behavior. For me it was visual C++ that did this out of order evaluation. Don't rely on order of evolution. C and C++ programmers don't rely as well.