Hello Florian,
I tried to check your assumption. I prepared a small code snipper which is
compiled successfully. I think, it may be considered as some "evidence".
autobld@pavo:base> cat simple.c
int main()
{
int x = 3;
__typeof__(x) y = 4;
long z;
z = (__typeof__(z)) (x + y);
char * s, * p;
p = (__typeof__(s))malloc(10);
return 0;
}
autobld@pavo:base> cc_r -o simple.o -c simple.c; echo $?
0
autobld@pavo:base> cc_r -o simple.o -q64 -c simple.c; echo $?
0
autobld@pavo:base> cc_r -qversion
C for AIX version 6.0.0.0
So, it looks like compiler understands the usage of __typeof__ in two use
cases: a) as a type cast, b) as a type in the variable declaration.
So far I incline to think that it is a problem of compiler itself, what do
you think?
--
Best Regards,
Alexander.
2016-10-31 10:05 GMT+01:00 Florian Weimer <fwei...@redhat.com>:
> On 10/28/2016 05:13 PM, TestRealTime . wrote:
>
>> Hello,
>>
>> I would like to report about two (probably, self-connected) bugs in the
>> __typeof__ C function.
>> These bugs are reproduced when I am trying to compile a simple code with
>> XLC compiler on AIX 5.2. Please, look at the code snippets below.
>>
>> 1. typeof_example_1.c
>> long Func(int x) { return x; }
>> int main()
>> {
>> int y, z = 1;
>> y = (__typeof__(Func(z)))0;
>> return 0;
>> }
>>
>> cc_r typeof_example_1.c
>> "typeof_example_1.c", line 5.26: 1506-045 (S) Undeclared identifier z.
>>
>> The 'z' variable is obviously defined, so "Undeclared identifier" message
>> is wrong.
>>
>
> Do you have any evidence that the compiler supports __typeof__ at all?
> Maybe the compiler treats __typeof__ as an implicitly declared function.
>
> What is interesting, we use cc_r, but not xlc binary in our build system
>> (it is probably due to historical reasons and persons who can answer me
>> why
>> exactly cc_r have gone many years ago). But with xlc both code snippets
>> also fail, however with other error messages (no matter, 32 or 64bit).
>> xlc typeof_example_1.c
>> "typeof_example_1.c", line 5.30: 1506-275 (S) Unexpected text integer
>> constant encountered.
>> xlc typeof_example_2.c
>> "typeof_example_2.c", line 5.41: 1506-275 (S) Unexpected text z
>> encountered.
>> "typeof_example_2.c", line 5.45: 1506-275 (S) Unexpected text integer
>> constant encountered.
>>
>
> Those syntax errors are consistent with not supporting __typeof__ at all.
> The expression parts which contain __typeof__ are not recognized as types,
> and so the expression is not recognized as a cast.
>
> Florian
>
