I have a project which is build for multiple platforms. For each platform the C++ standard is set to the maximum possible - so that we can work towards compliance with the latest standard.
The code itself, however, has to conformed to the lowest common standard with whatever ‘polyfills’ we have added to replicate newer behaviours on old versions of the standard.
The problem is the build wrapper detects C++17 and identifies smells such as:
const auto something(param1);
// do stuff
if ( const auto something(param1); something.someCondition())
// do stuff
Which is not legal before C++17.
For this project the sonar analysis is run for the build on the platform which a compiler that supports C++17 not the earlier compiler.
Can we set the sonar standard to an earlier standard and override the standard identified by the build wrapper?
I would rather not disable individual rules so that we can upgrade to a later standard in one go when possible.
Note also that the build wrapper is capturing “-std=gnu++1y”
but I expect sonar knows enough about gcc to know which subsets of C++17 this includes.
As a workaround I could alter the build script to replace this line in the build-wrapper-dump.json but I would rather treat this file as opaque and not depend on how sonar happens to be implemented.
This is similar to this issue C++: Set C++ version (14, 17, ...) to execute checks for.
However for that case he was using an old version of the scanner which did not automatically select rules based on the C++ standard identified by the build wrapper.