warn_possunwant

Controls the recognition of possible unintentional logical errors.

Syntax

#pragma warn_possunwant on | off | reset

Remarks

If you enable this pragma, the compiler checks for common, unintended logical errors:

An assignment in either a logical expression or the conditional portion of an if , while , or for expression. This warning message is useful if you use = when you mean to use == . The listing below shows an example.
Listing 1. Confusing = and == in Comparisons

if (a=b) f(); /* WARNING: a=b is an assignment. */

if ((a=b)!=0) f(); /* OK: (a=b)!=0 is a comparison. */

if (a==b) f(); /* OK: (a==b) is a comparison. */

An equal comparison in a statement that contains a single expression. This check is useful if you use == when you meant to use = . The listing below shows an example.
Listing 2. Confusing = and == Operators in Assignments
```
a == 0;        // WARNING: This is a comparison.
a = 0;         // OK: This is an assignment, no warning
```
A semicolon (; ) directly after a while , if , or for statement.
For example, the listing below, generates a warning message.
Listing 3. Empty statement

i = sockcount();
while (--i);  /* WARNING: empty loop. */
    matchsock(i);

If you intended to create an infinite loop, put white space or a comment between the while statement and the semicolon. The statements in the listing below, suppress the above error or warning messages.

Listing 4. Intentional empty statements

while (i++) ; /* OK: White space separation. */
while (i++) /* OK: Comment separation */ ;

By default, this pragma is off .