ISO 26262 is the functional safety standard for electrical and electronic systems in series production passenger cars. It requires qualification of all (electrical and electronic) components with respect to safety. The qualification process is described in the standard.
Qualification for safety is different from quality assurance because one has to take into account only the safety hazards that result from failure. While a broken door lock may be a serious quality issue, it is not likely to pose an immediate safety threat.
A second difference is that in safety qualification one always has to take into account the specific use case of the component: the same light-bulb used for either the indicator light or for the passenger interior light pose a different safety threat in those two use cases.
Usually, the compiler is not part of the on-board electronic systems. The compiler is used by the component developer, and it is the compiler-generated code that goes into the car. Clearly, if the compiler generates incorrect code and the component that contains that code is part of the control system of the car, this can have serious consequences. For that reason, functional safety standards, including ISO 26262, define that the tools used to create components are also subject to qualification. The compiler is one such tool – its correctness can have serious impact on the safety of the car.