Beginner-unfriendly behavior of long int initialization #1629
Description
Describe the request
Request: Implement IDE warnings for integer assignments that do not behave as a beginner would expect.
Rationale: Experienced C programmers will know that
long int x = 100 * 1000;
is a dangerous thing to write, because the two numbers will be interpreted as plain ints. As a consequence, when compiled on an Arduino Uno, the multiplication is interpreted as a 16-bit operation, and the end result will be x = 34,464. A beginner might reasonably expect that x = 100,000 at the end of this. While I fully realize that silent integer overflow is a problem with the C/C++ language rather than with the Arduino IDE per se, the fact is that may Arduino users may not be C/C++ experts. In fact, one of the key reasons that Arduino is so popular, is that for the most part you don't have to be a C/C++ expert to use it.
Another great example is
delay(66*1000)
which most people would expect to result in a 66 second delay. In fact, 66*1000 overflows to 464, so the actual delay is less than half a second.
If it is not possible to make the compiler understand the obvious intention in these cases, it would be really helpful if the IDE could flag this sort of thing with a visible warning.
Describe the current behavior
The Arduino IDE does not notice calculations where C quirks result in different results than a casual user would expect. No compiler warnings are generated either.
Arduino IDE version
2.0.1
Operating system
Linux
Operating system version
Ubuntu 22.04
Additional context
No response
Issue checklist
- I searched for previous requests in the issue tracker
- I verified the feature was still missing when using the latest nightly build
- My request contains all necessary details