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In article <1992Apr9.213900.26576@urbana.mcd.mot.com>
qbarnes@urbana.mcd.mot.com (Quentin Barnes) writes:
>I have a few questions about the ANSI C spec (X3.159-1989 section
>3.8) and how an ANSI C preprocessor should behave. 

The ANSI standard does not concern itself with separate preprocessors.
It defines only a `preprocessing phase' of C compilation.  Whether that
is implemented separately, or as part of an integrated compiler program,
is up to the implementation.

>1) When a conforming preprocessor encounters a '#' directive which
>   is not listed in the preprocessor syntax (ex. '#foo'), what is
>   the correct behavior -- declare a fatal error, display a warning,
>   or pass it unchanged silently to the compiler?

When a conforming *compiler* (including all 7 phases) encounters an
program violating a constrant, it must emit at least one diagnostic.

>2) A conforming preprocessor must output line directives (3.8.4) ...

3.8.4 deals with *input* line directives.

GCC's cpp could emit encrypted binary data and still conform, as long as
the rest of the system performed according to the specifications.

The C standard acts as a contract between a `user' and an
`implementor'.  Each may view the other as a `black box'.  The user is
required to feed the implementor conforming code; the implementor is
required to accept conforming code and produce conforming output.

The black boxes, in this case, are defined only at the level of `C
source code' and `observable behavior when running the compiler and the
compiled code'.  The preprocessor, if there is a separate one, is not
considered an `observable part'.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 510 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov