SA0095: Assignments in conditions

Detects assignments in conditions of IF, CASE, or REPEAT constructs

Justification: An assignment (:=) and a comparison (=) can easily be mistaken. As a result, an assignment in a condition can easily be unintentional, and it is therefore reported. This can also confuse the reader of the code.

Importance: High

Example 88. Example

PROGRAM PLC_PRG
VAR
    iCond1:INT := INT#1;
    iCond2:INT := INT#2;
    xCond:BOOL := FALSE;
    iVar : INT;
END_VAR

IF INT_TO_BOOL(iCond1 := iCond2) THEN    // SA0095
    iCond1 := INT#1;
    iCond2 := INT#2;
    ELSIF (iCond1 := 11) = 11 THEN    // SA0095
        iCond1 := INT#1;
        iCond2 := INT#2;
END_IF

IF xCond := TRUE THEN    // SA0095
    xCond := FALSE;
END_IF

IF (xCond := FALSE) OR (iCond1 := iCond2) = 12 THEN    // SA0095
    xCond := FALSE;
    iCond1 := INT#1;
    iCond2 := INT#2;
END_IF

IF (iVar := iVar + 1) = 120 THEN    // SA0095 (can be valid, but is not reparable very well
    iVar := 0;
END_IF

WHILE (xCond = TRUE) OR (iCond1 := iCond2) = 12 DO    // SA0095
    xCond := FALSE;
END_WHILE

//Error: assignment in repeat loop
REPEAT
    xCond := FALSE;
UNTIL (xCond = TRUE) OR (iCond1 := iCond2) = 12    //  SA0095
END_REPEAT

Output in the Messages view:

SA0095: Assignment in condition: '...'