C compiler for pdp-11 under RSX

Alan S. Driscoll alan at allegra.UUCP
Sun Jun 10 10:22:05 AEST 1984

> On many systems, the loader doesn't speak COMMON blocks and requires
> that a single module (file) EXPORT a symbol and that all other modules
> IMPORT it.  When compiling C code a file at a time, there is no way to
> do this with the existing language definition.

As Henry Spencer has already pointed out, the definition of C doesn't
require that unitialized data be made common, although many existing
compilers do this.  (I know, some sloppy code depends on it.)

To export a symbol, you say something like

	int foo;

To import it, you say

	extern int foo;

There really isn't any problem.

	Alan S. Driscoll
	AT&T Bell Laboratories

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