[BUG] (bug summary)\macros.h:418:20: warning: comparison between signed and unsigned integer #25459
Description
Did you test the latest bugfix-2.1.x code?
No, but I will test it now!
Bug Description
In file included from e:\marlin2\marlin\src\inc\MarlinConfigPre.h:37:0,
from e:\marlin2\marlin\src\inc\marlinconfig.h:28,
from Marlin\src\gcode\feature\trinamic\M122.cpp:23:
e:\marlin2\marlin\src\core\macros.h: In instantiation of 'constexpr decltype ((lhs + rhs)) _MAX(L, R) [with L = int; R = unsigned int; decltype ((lhs + rhs)) = unsigned int]':
Marlin\src\gcode\feature\trinamic\M122.cpp:50:64: required from here
e:\marlin2\marlin\src\core\macros.h:418:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
return lhs > rhs ? lhs : rhs;
Bug Timeline
?
Expected behavior
Compile without this error
Actual behavior
No response
Steps to Reproduce
Compiling using Platformio
Version of Marlin Firmware
2.0.x bugfix(3/2/23)
Printer model
Prusa MK3S - Einsy
Electronics
No response
Add-ons
No response
Bed Leveling
None
Your Slicer
None
Host Software
None
Don't forget to include
- A ZIP file containing your
Configuration.handConfiguration_adv.h.
Additional information & file uploads
Chatgpt suggests...
This warning suggests that there is a comparison being made between a signed integer (lhs) and an unsigned integer (rhs). Since signed and unsigned integers are stored differently in memory, this can cause unexpected behavior and lead to bugs in your code.
To resolve this warning, you can modify the _MAX function in the macros.h file to use the same data type for both the lhs and rhs parameters. One possible solution is to add a type cast to convert the unsigned integer to a signed integer before making the comparison: c++
template<typename L, typename R>
constexpr decltype(auto) _MAX(L lhs, R rhs) {
return lhs > static_cast(rhs) ? lhs : static_cast(rhs);
}
By adding the static_cast(rhs) expression, we are explicitly converting the rhs parameter to the same data type as lhs, which will resolve the warning and ensure that the function works as intended.
However, it's important to note that modifying the macros.h file can have unintended consequences and cause other errors or issues. Therefore, it's recommended to test your changes thoroughly and seek assistance from the Marlin firmware community or developers if you're unsure about how to proceed.
Configuration.h.txt
Configuration_adv.h.txt