Re: [Libguestfs] [PATCH libnbd v3 2/6] generator: Add attribute((nonnull)) annotations to non-NULL parameters

> > + (* Output __attribute__((nonnull)) for the function parameters: > > + * eg. struct nbd_handle *, int, char * > > + * => [ true, false, true ] > > + * => LIBNBD_ATTRIBUTE_NONNULL((1,3)) > > + * => __attribute__((nonnull,(1,3))) > > Style question. Do we want to REQUIRE the clients of this macro to > pass in (), or would it be better to have a varargs format? > > > + *) > > + let nns : bool list = > > + [ true ] (* struct nbd_handle * *) > > + @ List.flatten (List.map arg_attr_nonnull args) > > + @ List.flatten (List.map optarg_attr_nonnull optargs) in > > + let nns = List.mapi (fun i b -> (i+1, b)) nns in > > + let nns = filter_map (fun (i, b) -> if b then Some i else None) nns in > > + let nns : string list = List.map string_of_int nns in > > + pr "\n LIBNBD_ATTRIBUTE_NONNULL((%s));\n" (String.concat "," nns) > > For generated code, it is just as easy to cope with either style (we > can strip a layer of () if we want a varargs format). >

> > + pr "#ifndef LIBNBD_ATTRIBUTE_NONNULL\n"; > > + pr "#if defined(__GNUC__) && LIBNBD_GCC_VERSION >= 120000 /* gcc >= 12.0 */\n"; > > + pr "#define LIBNBD_ATTRIBUTE_NONNULL(s) __attribute__((__nonnull__ s))\n"; > > This definition is what requires us to pass in our own (). That is, > our end result is going to be one of: > > __attribute__((__nonnull__(1) )) > __attribute__((__nonnull__(1, 2) )) > > but the difference is whether we must pass exactly one macro argument, > and where that argument must include () even when there is only one > parameter to be marked (what you coded): > > LIBNBD_ATTRIBUTE_NONNULL((1)) > LIBNBD_ATTRIBUTE_NONNULL((1, 3)) > > vs. ease-of-use in supplying the () as part of the macro definition > itself by using #define MACRO(...) and __VA_ARGS__: > > LIBNBD_ATTRIBUTE_NONNULL(1) > LIBNBD_ATTRIBUTE_NONNULL(1, 3) I'm not sure I understand - what does the second definition look like?