This is the mail archive of the
mailing list for the binutils project.
Re: [PATCHv2 1/3] opcodes/arc: Move instruction length logic to new function
- From: Nick Clifton <nickc at redhat dot com>
- To: Andrew Burgess <andrew dot burgess at embecosm dot com>
- Cc: binutils at sourceware dot org, Claudiu dot Zissulescu at synopsys dot com, Cupertino dot Miranda at synopsys dot com, noamca at mellanox dot com
- Date: Wed, 13 Apr 2016 16:30:38 +0100
- Subject: Re: [PATCHv2 1/3] opcodes/arc: Move instruction length logic to new function
- Authentication-results: sourceware.org; auth=none
- References: <cover dot 1460458691 dot git dot andrew dot burgess at embecosm dot com> <cb64992909da171def628e036ee5f6cc94e71058 dot 1460458691 dot git dot andrew dot burgess at embecosm dot com> <570E4A76 dot 5020504 at redhat dot com> <20160413144058 dot GB5531 at embecosm dot com>
>> Would this function ever return a negative value ? I assume not, so
>> it would make sense for its return type to be "unsigned int".
> I'm not sure is the answer. I agree that arc_insn_length will never
> return a negative, however, the return value from arc_insn_length is
> used to prime a variable that is then the return value for
> print_insn_arc, which is also defined to return 'int', and is part of
> the disassembler API, and does return a negative value if there's an
> It was this relationship that originally lead me to make
> arc_insn_length return an 'int'.
> Given that it will only ever return small positive integers there
> should be no problem making it return an unsigned value then casting
> to int in print_insn_arc - would this be preferred?
Yes. Or (better IMHO) just explicitly set the return value for
print_insn_arc based upon testing the return value from arc_insn_length.
Ie something like:
len = arc_insn_length (...);
if (len == 0)
(I am assuming here that a returned length of zero should never happen
with a valid instruction, and can therefore be used as an error return