2011/5/25 Eric Blake <eblake@redhat.com>:
On 05/25/2011 10:23 AM, Daniel P. Berrange wrote:
On Mon, May 23, 2011 at 07:36:10PM +0200, Matthias Bolte wrote:
Remove some special case code that took care of mapping hyper to the correct C types.
Use macros for hyper to long assignments that perform overflow checks when long is smaller than hyper. Also use such macros for the safe hyper to longlong assignemts as this allows to keep the generator a bit simpler.
+ } elsif ($ret_member =~ m/^(unsigned )?hyper (\S+)\[\S+\];/) { + # error out on unannotated hypers + die "(unsigned)? hyper without (u)?(long|longlong) annotation: $ret_member";
'hyper' in XDR world is a fixed 64 bit type, so IMHO, this should automatically map to 'long long' in the API, without requiring an annotation.
eg, we should only annotate if the public API uses the variable sized 'long' / 'unsigned long' types in C.
All the 'longlong' and 'ulonglong' annotations should be removed here IMHO, since they should be the default for hyper/unsigned hyper.
If we add a new API that uses 'long' but forget the annotation, then we have silent type mismatch in the generated code. Since we are using hyper for both types in C, I find it better to require an annotation on all uses to be explicit on which type we meant, rather than defaulting the lack of annotation as 'long long' and only requiring annotation for 'long' - that is, I find that from the maintenance aspect, having the code generator explicitly fail because you forget an annotation (even if the annotation is the default of llong) is safer than risking silent code misgeneration.
But anything is better than nothing, so I won't give any further complaints if we go with your idea of only annotating the exceptions to the 'long long' default, rather than all uses of hyper.
I think that being more explicit here is better and would like to stick with annotating all hyper members. This way we cannot overlook a missing (u)long annotation in a review because the generator will complain for us. Matthias