Eduardo Habkost <[email protected]> writes:
> On Thu, Nov 19, 2020 at 01:21:58PM -0500, Eduardo Habkost wrote:
>> On Thu, Nov 19, 2020 at 11:24:52AM +0100, Markus Armbruster wrote:
> [...]
>> > >> > > + return qnum_from_value((QNumValue) QNUM_VAL_INT(value));
>> >
>> > No space between between (type) and its operand, please.
>> >
>> > Could we lift the cast into the macro somehow?
>>
>> I think we can. I had thought the cast in the macro would break
>> usage as static variable initializers. I was wrong.
>
> Actually, including the cast in the macro breaks QLIT_QDICT
> initializers (which use (QLitDictEntry[]) compound literals), and
> I don't know why.
>
> Compound literals in initializers of static variables is a GCC
> extension. I don't understand why it doesn't work inside array
> compound literals, though.
>
> Any language lawyers around?
>
> This works:
>
> typedef struct QLit {
> int x, y;
> } QLit;
>
> typedef struct Entry {
> int key;
> QLit value;
> } Entry;
>
> Entry e = { .key = 0, .value = (QLit) { 1, 2 } };
>
> This works:
>
> Entry *es1 = (Entry[]) {
> { .key = 0, .value = { 1, 2 } },
> };
>
> But this doesn't:
>
> Entry *es2 = (Entry[]) {
> { .key = 0, .value = (QLit) { 1, 2 } },
> };
>
> dict.c:16:24: error: initializer element is not constant
> 16 | Entry *es2 = (Entry[]) {
> | ^
> dict.c:16:24: note: (near initialization for ‘es2’)
>
> (gcc (GCC) 10.2.1 20201005 (Red Hat 10.2.1-5))
Can't explain this offhand.
Another pecularity: a const QLitObject is for the most part not actually
const. Evidence:
$ size
bld-x86/libqemu-x86_64-softmmu.fa.p/meson-generated_.._qapi_qapi-introspect.c.o
text data bss dec hex filename
19590 351600 48 371238 5aa26
bld-x86/libqemu-x86_64-softmmu.fa.p/meson-generated_.._qapi_qapi-introspect.c.o
Score 5 out of 100 points.
