[testsuite,Android] Add <stdlib.h> to pr56407.c

Hi,

The following test case fails to compile on Android: gcc.dg/torture/pr56407.c

/tmp/ccA08Isw.o:pr56407.c:function test: error: undefined reference to 'rand'
collect2: error: ld returned 1 exit status

Which is not surprising at all, since the testcase has only the
declarations of abort() and rand()
and doesn't have any headers included.

The following patch adds <stdlib.h> to the test.
Tested on x86_64-unknown-linux-gnu and on Android. Also I checked that
the original regression appears on the fixed test.

Is it OK for trunk?



--Alexander

On 5/08/2013, at 10:57 PM, Alexander Ivchenko wrote:

> Hi,
> 
> The following test case fails to compile on Android: gcc.dg/torture/pr56407.c
> 
> /tmp/ccA08Isw.o:pr56407.c:function test: error: undefined reference to 'rand'
> collect2: error: ld returned 1 exit status
> 
> Which is not surprising at all, since the testcase has only the
> declarations of abort() and rand()
> and doesn't have any headers included.

It *is* surprising given that the testcase does have declarations of abort() or rand() -- which are the only two external functions referenced.

> 
> The following patch adds <stdlib.h> to the test.

I don't think this a correct fix.  [In most such cases the real problem can be found out by examining why linking a test against glibc works, but against bionic -- doesn't.]

How are you linking this testcase?  Please post both the link line from testsuite log and verbose output of linking (obtainable by adding "-v" to the link line).

Thank you,

--
Maxim Kuvyrkov
www.kugelworks.com

The reason for undefined reference to rand is that it is defined as
"static __inline__" in Bionic stdlib.h:

static __inline__ int rand(void) {
    return (int)lrand48();
}

So in fact, if you do "nm libc.so" for Bionic, you won't get the
rand.. which is probably not correct, because it doesn't have the
external linkage. I added Elliott.

Still, in C standart it is said that rand is defined in stdlib.h, and
we don't include it in that testcase.


thanks,
Alexander


2013/8/5 Maxim Kuvyrkov <maxim@kugelworks.com>:
> On 5/08/2013, at 10:57 PM, Alexander Ivchenko wrote:
>
>> Hi,
>>
>> The following test case fails to compile on Android: gcc.dg/torture/pr56407.c
>>
>> /tmp/ccA08Isw.o:pr56407.c:function test: error: undefined reference to 'rand'
>> collect2: error: ld returned 1 exit status
>>
>> Which is not surprising at all, since the testcase has only the
>> declarations of abort() and rand()
>> and doesn't have any headers included.
>
> It *is* surprising given that the testcase does have declarations of abort() or rand() -- which are the only two external functions referenced.
>
>>
>> The following patch adds <stdlib.h> to the test.
>
> I don't think this a correct fix.  [In most such cases the real problem can be found out by examining why linking a test against glibc works, but against bionic -- doesn't.]
>
> How are you linking this testcase?  Please post both the link line from testsuite log and verbose output of linking (obtainable by adding "-v" to the link line).
>
> Thank you,
>
> --
> Maxim Kuvyrkov
> www.kugelworks.com
>
>

Alexander Ivchenko <aivchenk@gmail.com> writes:

> Still, in C standart it is said that rand is defined in stdlib.h, and
> we don't include it in that testcase.

It also says: "Provided that a library function can be declared without
reference to any type defined in a header, it is also permissible to
declare the function and use it without including its associated
header."

Andreas.

Thanks Andreas, it seems clear now that Bionic rand function is not
consistent with the standart.


--Alexander

2013/8/6 Andreas Schwab <schwab@suse.de>:
> Alexander Ivchenko <aivchenk@gmail.com> writes:
>
>> Still, in C standart it is said that rand is defined in stdlib.h, and
>> we don't include it in that testcase.
>
> It also says: "Provided that a library function can be declared without
> reference to any type defined in a header, it is also permissible to
> declare the function and use it without including its associated
> header."
>
> Andreas.
>
> --
> Andreas Schwab, SUSE Labs, schwab@suse.de
> GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
> "And now for something completely different."