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

lint: C Program Checker XENIX Programming
treats main.c and add.c as two parts of a complete program.
If lint discovers errors or inconsistencies in a source file, it produces messages
describing the problem. The message has the form
filename ( num ) : description
where filename is the name of the source file containing the problem, num is the
number of the line in the source containing the problem, and description is a description
of the problem. For example, the message
main.c (3): warning: x unused in function main
shows that the variable x, defined in line 3 of the source file main.c, is not used
anywhere in the file.
Checking for Unused Variables and Functions
The lint program checks for unused variables and functions by seeing if each declared
variable and function is used at least once in the source file. The program considers a
variable or function used if the name appears in at least one statement. It is not
considered used if it only appears on the left side of an assignment. For example, in the
following program fragment
main ()
{
int x, y, z;
X= 1; y = 2; Z =X+ y;
the variables x and y are considered used, but variable z is not.
Unused variables and functions often occur during the development of large programs. It
is not uncommon for a programmer to remove all references to a variable or function
from a source file but forget to remove its declaration. Such unused variables and
functions rarely cause working programs to fail but do make programs harder to
understand and change. Checking for unused variables and functions can also help you
find variables or functions that you intended to used but have accidentally left out of
the program.
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