Compiler Directives

There are four compiler directive statements. Each of these statements begins with a dollar sign ($).

Comments in the Object Code

The $* statement places a comment directly in the object code of a program when it is compiled. It is most useful for entering version numbers or copyright information before software is distributed.

Reading External Source Code ($CHAIN, $INCLUDE, $INSERT)

Three statements tell the compiler to read source code from another file item: $INCLUDE, $INSERT, and $CHAIN.

$INCLUDE and $INSERT are identical statements. Either statement results in the program being compiled as if the external source code were written at the point where the $INCLUDE or $INSERT statement had been entered. Compilation will then continue at the line after the $INCLUDE or $INSERT statement. $INCLUDE and $INSERT are also useful for any code that might be used by several different programs. An example of such code might be a file item containing COMMON statements.

The $CHAIN statement is different from $INCLUDE and $INSERT in that the compilation will not return to the original program. The $CHAIN statement is not intended for code which might be shared by several programs, but for programs which may have source code longer than 32K bytes. The $CHAIN statement allows several different file items containing source code to be CHAINed together.

The only restriction to $INCLUDE, $INSERT, and $CHAIN is that the number of bytes in the resulting object code cannot exceed 248K.