Intel XENIX 286 Programmers Guide (86) - Tenox.tc

lint: C Program Checker XENIX Programming
A similar issue arises with bitfields. When assignments of constant values are made to
bitfields, the field may be too small to hold the value. This is especially true here on
some machines bitfields are considered as signed quantities. While it may seem
counter-intuitive to consider that a 2-bit field declared of type int cannot hold the value
3, the problem disappears if the bitfield is declared to have type unsigned.
Checking for Assignment of longs to ints
Bugs may arise from the assignment of a long to an int, because of a loss in accuracy in
the process. This may happen in programs that have been incompletely converted by
changing type definitions with typedef. When a typedef variable is changed from int to
long, the program can stop working because some intermediate results may be assigned
to integer values, losing accuracy. Since there are a number of legitimate reasons for
assigning longs to integers, you may wish to suppress detection of these assignments by
using the -a option.
Checking for Strange Constructions
Several perfectly legal but somewhat strange constructions are flagged by lint. The
generated messages encourage better code quality and clearer style, and may even point
out bugs. For example, in the statement
*p + + ;
the asterisk (*) does nothing and lint prints
null effect
The program fragment
unsigned x;
if (x < 0) ...
is also strange since the test will never succeed. Similarly, the test
unsigned x;
if (x > 0) ...
is equivalent to
3-8
unsigned x;
if( X ! = 0) ...