## 'function' is a non-ANSI definition

You have declared the main entry point using an old-style function definition. main should be an ANSI-prototyped function. The compiler only reports this warning when extra-picky ANSI warnings are enabled.

Old-style function definitions, although valid, should not be used because they are a common source of errors and lead to code which is less efficient than a prototyped function. A function which takes no parameters should be declared with the parameter list (void).

## 'type' is a non-ANSI type

The `long long` type and its unsigned variant are not supported by ANSI C. The CrossWorks C compiler supports this type as you would expect.

## 'type' used as an lvalue

You used an object of type type as an lvalue. Assigning through an uncast, dereferenced `void *` pointer is an error and will result in this error.

## empty declaration

A declaration does not declare any variables (or types in the case of `typedef`).

## empty input file

The input file contains no declarations and no functions. A C file which contains only comments will raise this warning.

## local 'type name' is not referenced

The local declared variable name is not referenced in the function.