integer overflow in explorer

[pk19604014]

trafficstars

package P api;

fn Main() -> i32 { var count: i32 = 5; while (not (count == 0)) { count = count - 112722749; } return 0; }

$ bazel run explorer:explorer /tmp/crash.carbon ... interpreter.cpp:172:69: runtime error: signed integer overflow: -2141732226 - 112722749 cannot be represented in type 'int'

[pk19604014]

Not sure whether this should be caught and reported as a program error or left as is.

[zygoloid]

I think explorer should be catching this and reporting it as a runtime error, rather than leaving it to ubsan to diagnose.

[pk19604014]

Thanks.

Relevant Discord discussion -- https://discord.com/channels/655572317891461132/763516049710120960/982378627968675930 One of recommendations was to look into llvm's APInt -- https://llvm.org/doxygen/classllvm_1_1APInt.html

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[guille2718]

The current explorer catches this as a runtime error

RUNTIME ERROR: /home/guille/test.carbon:6: integer overflow

I guess this issue can be closed now.

[geoffromer]

Yeah, looks like #2737 fixed this.