Echelon Neuron - Manual (Page 74)

66 Neuron C Compiler Errors (NCC)
NCC# Description
170 Cannot have ‘io_changes’ & ‘io_update_occurs’ on same I/O object [NCC#170]
The Neuron C event expressions for io_update_occurs and io_changes (with
its various options) only apply to I/O objects that are inputs. Furthermore,
some events are not applicable to some input object types. Only one form of
event expression can be used per I/O object. A maximum of 15 I/O objects
can have io_update_occurs and io_changes events. The syntax of all the
event expressions requires the event type to be followed by the object name,
in parentheses.
171 Improper context for ‘continue’ statement [NCC#171]
A continue statement can only occur inside a do, for, or while statement. It
causes execution to immediately branch back to the first statement of the
loop statement that contains the continue statement.
172 Function definition does not allow return value [NCC#172]
The function, whose declared return data type is void, has a statement of
the form return expression .
173 Expression has no effect - discarded [NCC#173]
The compiler outputs this warning diagnostic when the optimizer discards
an expression. Examples of such expressions are:
x = y-1, z; /* y-1 is discarded */
a+3; /* a+3 is discarded */
x == 1? y: z; /* z is discarded */
174 Return value of function was ignored [NCC#174]
A function that has a return type (other than void) is used in an expression,
but the caller discards the return value without it being used or stored.
The warning can be removed by casting the return of the function to void.
Example:
int f(void) {return 0;}
when (reset) {
(void)f();
}
175 This event will never be reached [NCC#175]
This message warns of the use of a specific, qualified event following a
generic, unqualified event in the same class. As the generic one will catch
the event first, the specific one will never evaluate to TRUE. This condition
can only occur when using the scheduler_reset feature. (Failure to use the
scheduler_reset feature with multiple event expressions that are not
exclusive can result in unstable behavior.)