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From: bet@ecsvax.UUCP
Newsgroups: net.lang.c
Subject: Re: Preprocessor Trickery
Message-ID: <2825@ecsvax.UUCP>
Date: Mon, 2-Jul-84 10:52:24 EDT
Article-I.D.: ecsvax.2825
Posted: Mon Jul  2 10:52:24 1984
Date-Received: Tue, 3-Jul-84 04:49:01 EDT
Lines: 18

Someone made a comment earlier that seems to have been ignored by many,
that efforts like X/**/Y and the QUOTE macro *aren't* guaranteed to be
portable, and further that *no* mechanism is guaranteed to be portable,
since in theory the cpp functionality is defined in terms of *tokens*.
That is to say, the standard, *required* behavior of cpp could be produced
by code between the lexical analyzer and the parser. Composite token
creation can only really be expected to show up when cpp is a distinct
pass of the compiler, producing "clear", preprocessed C as an intermediate
step, which then undergoes another lexical analysis. In fact this
is not the only way that compilers are created -- small, fast single pass
compilers for micros, to keep the amount of overlaying required down,
sometimes build the functionality of cpp *into* the compiler. A second
lexical analysis is legitimately considered an unnecessary waste of
time and space. Let us keep in mind that one of the strongest aspects
of C is how good a language it is for small systems.

					Bennett Todd
					...{decvax,ihnp4,akgua}!mcnc!ecsvax!bet