Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!watmath!clyde!cbosgd!gatech!seismo!topaz!brisco
From: brisco@topaz.RUTGERS.EDU (T.p.)
Newsgroups: net.lang.c
Subject: problems with the C parser
Message-ID: <5072@topaz.RUTGERS.EDU>
Date: Thu, 29-May-86 17:44:01 EDT
Article-I.D.: topaz.5072
Posted: Thu May 29 17:44:01 1986
Date-Received: Sat, 31-May-86 05:08:32 EDT
Organization: Rutgers Univ., New Brunswick, N.J.
Lines: 40
Keywords: bitfield,structure,'%&#@*




	I've been trying to translate a program written in Vax
Pascal to C on our Suns.
	My problem arose when I was trying to translate a pascal
variant record structure into a C union structure. The structure type
(in pascal) looked as follows: (keep in mind - both were for 32 bit machines)

	newtype = record case selector of
		0:(int: unsigned);
		1:(bool: packed array [0..31] of boolean);
		end


	Which I had translated into C as:

	typedef union {
		int intfield;   /* change the record name - keyword */
		struct bool{unsigned x[32]:1};
		} newtype;


	The C parser barfed all over this. I tried every combination
of unsigned x:1[32], ..... that I could think of.  Out of frustration
I looked up the syntax of the declarations in K&R and found that the
initial guess had been correct!
	I wanted an integer that I could index into by bit, so I could
avoid using masks (which weren't going to be easily used due to the
methodology of the original program).
	Am I going crazy or is our C parser brain-damaged?  Can anyone
else compile the above structure declaration?


			"Wah!"
			"No, no. It's 'Wah!'"
			"Wah!"
			"That's better!"

				tp.