This is the mail archive of the
cgen@sources.redhat.com
mailing list for the CGEN project.
Re: debugging help?
- To: Ben Elliston <bje at redhat dot com>
- Subject: Re: debugging help?
- From: Alan Lehotsky <apl at alum dot mit dot edu>
- Date: Tue, 8 May 2001 20:10:03 -0400
- Cc: lehotsky at earthlink dot net, cgen at sourceware dot cygnus dot com
- References: <15096.33343.222519.11808@scooby.apac.redhat.com>
At 9:33 AM +1000 5/9/01, Ben Elliston wrote:
> >>>>> "lehotsky" == lehotsky <lehotsky@earthlink.net> writes:
>
> lehotsky> the cgen code doesn't seem to issue very useful error messages.
> lehotsky> Any suggestions on how to track down this problem?
>
>I see Frank has already answered, this, however ..
>
> lehotsky> Computing sformat argument buffers ...
> lehotsky> ERROR: bad bitsize argument to gen-ifetch 4
> lehotsky> No backtrace available.
> lehotsky> make[1]: *** [cgen-cpu-decode] Error 1
>
>It so happens that I recognise this one. It is often caused by
>instruction formats (the "(+ ...)" clause) missing one or more
>bits--or containing overlapping ifields.
>
>Ben
And you're right. I had looked at all my (+ ....) patterns and discovered that
I had entered the SAME field twice! If I was a "schemer" (or a conniver - sorry, old
MIT joke....), I'd try to write code that would identify that case and issue a better warning
message.
Frankly, I like the cgen "language", but the error diagnostics REALLY are terrible.
It takes a lot of fumbling around to figure out what it's really complaining about most of the
time.....
-- Al
--
------------------------------------------------------------------------
Quality Software Management
http://home.earthlink.net/users/~qsmgmt
apl@alum.mit.edu
(978)287-0435 Voice
(978)808-6836 Cell
(978)287-0436 Fax
Software Process Improvement and Management Consulting
Language Design and Compiler Implementation