demo-epb/misra/records-md/MISRA-Record-001.md

record-id, project, date, status

record-id	project	date	status
MISRA-REC-001	demo-epb	2026-05-11	Approved

MISRA Deviation Record MISRA-REC-001

Field	Value
Record ID	MISRA-REC-001
Date	2026-05-11
File	src/apply_controller.c
Function	apply_ctrl_step_50ms
Line	64
Standard	MISRA C:2012
Rule	Rule 15.5 (Advisory) — "A function should have a single point of exit"
ASIL	D
Status	Approved

---

1. Code excerpt

void apply_ctrl_step_50ms(const ApplyInputs* in)
{
    if (in == NULL) {
        s_ctx.last_error = EPB_EINVAL;
        return;            /* <-- early exit */
    }
    ...
}

2. Rationale

The NULL pointer check as an early exit significantly improves readability versus a nested variant with a single return at the end. MISRA Rule 15.5 is Advisory, not Required.

The early exit has clearly defined semantics (input validation) and does not impair verifiability; on the contrary, the separate path is unambiguously covered in the unit test test_null_input.

3. Alternative considered

Single-exit variant:

void apply_ctrl_step_50ms(const ApplyInputs* in)
{
    if (in == NULL) {
        s_ctx.last_error = EPB_EINVAL;
    } else {
        /* entire step logic nested in else branch */
        ...
    }
}

Rejected because the additional nesting makes the state machine harder to read without gaining functional equivalence relative to the early-exit variant.

4. Safety impact

None. The early exit is deterministic and covered by the unit test.

5. Approval

Role	Name	Date	Signature
Technical Lead	Stefan Lohmaier	2026-05-11	(demo)
Safety Manager	(in real project)	2026-05-11	(demo)

6. Scope

This deviation applies only to this specific code site. Other early-exit sites require separate records.