Missing documentation

[Neil Booth]

This documents -fpreprocessed (and removes an unnecessary comment
about trigraphs being brain-damaged.  I can't argue with that, but
I don't think it belongs in the manual).

I'll commit to both trees.

Neil.

	* cppinit.c (print_help): Document -fpreprocessed.
	* invoke.texi: Similarly.

Index: cppinit.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cppinit.c,v
retrieving revision 1.159
diff -u -p -r1.159 cppinit.c
--- cppinit.c	2001/05/20 06:26:33	1.159
+++ cppinit.c	2001/06/09 22:43:09
@@ -1885,6 +1885,7 @@ Switches:\n\
   -dI                       Include #include directives in the output\n\
 "), stdout);
   fputs (_("\
+  -fpreprocessed            Treat the input file as already preprocessed\n\
   -ftabstop=<number>        Distance between tab stops for column reporting\n\
   -P                        Do not generate #line directives\n\
   -$                        Do not allow '$' in identifiers\n\
Index: doc/invoke.texi
===================================================================
RCS file: /cvs/gcc/gcc/gcc/doc/invoke.texi,v
retrieving revision 1.5
diff -u -p -r1.5 invoke.texi
--- invoke.texi	2001/06/09 13:32:45	1.5
+++ invoke.texi	2001/06/09 22:43:37
@@ -1023,9 +1023,8 @@ freestanding and hosted environments.
 
 @item -trigraphs
 @opindex trigraphs
-Support ISO C trigraphs.  You don't want to know about this
-brain-damage.  The @option{-ansi} option (and @option{-std} options for
-strict ISO C conformance) implies @option{-trigraphs}.
+Support ISO C trigraphs.  The @option{-ansi} option (and @option{-std}
+options for strict ISO C conformance) implies @option{-trigraphs}.
 
 @cindex traditional C language
 @cindex C language, traditional
@@ -4015,6 +4014,18 @@ Only @samp{#define @var{name}} is includ
 @opindex dI
 Output @samp{#include} directives in addition to the result of
 preprocessing.
+
+@item -fpreprocessed
+@opindex fpreprocessed
+Indicate to the preprocessor that the input file has already been
+preprocessed.  This suppresses things like macro expansion, trigraph
+conversion, escaped newline splicing, and processing of most directives.
+In this mode the integrated preprocessor is little more than a tokenizer
+for the front ends.
+
+@samp{-fpreprocessed} is implicit if the input file has one of the
+extensions @samp{i}, @samp{ii} or @samp{mi} indicating it has already
+been preprocessed.
 
 @item -trigraphs
 @opindex trigraphs