Re: [PATCH/libiberty] fix build of gdb/binutils with clang.

[Yunlian Jiang <yunlian@google.com>]

There was a similar disscussion here
https://gcc.gnu.org/ml/gcc/2005-11/msg01190.html

The problem is in the configure stage, the __GNU_SOURCE is not
defined, and it could not find
the declaration of asprintf. so it make a declaration of asprintf in
libiberty.h. And  for the file floatformat.c,
the  __GNU_SOURCE is defined, so it could find another asprintf in
/usr/include/bits/stdio2.h, it also includes
libiberty.h. So these two asprintf conflicts when __USE_FORTIFY_LEVEL is set.

On Sat, May 2, 2015 at 11:58 AM, Ian Lance Taylor <iant@google.com> wrote:
> On Fri, May 1, 2015 at 4:45 PM, Yunlian Jiang <yunlian@google.com> wrote:
>> The test case does not have #define _GNU_SOURCE, so it says
>> error: ‘asprintf’ undeclared (first use in this function)
>
> OK, then my next question is: why does the test case (I assume you
> mean the test case for whether to set HAVE_DECL_ASPRINTF) not have
> #define _GNU_SOURCE?
>
> What is the background here?
>
> Ian
>
>> On Fri, May 1, 2015 at 3:45 PM, Ian Lance Taylor <iant@google.com> wrote:
>>> On Tue, Apr 28, 2015 at 2:59 PM, Yunlian Jiang <yunlian@google.com> wrote:
>>>> I believe this is the same problem as
>>>> https://gcc.gnu.org/ml/gcc-patches/2008-07/msg00292.html
>>>>
>>>> The asprinf declaration is  messed up when using clang to build gdb.
>>>>
>>>> diff --git a/include/libiberty.h b/include/libiberty.h
>>>> index b33dd65..a294903 100644
>>>> --- a/include/libiberty.h
>>>> +++ b/include/libiberty.h
>>>> @@ -625,8 +625,10 @@ extern int pwait (int, int *, int);
>>>>  /* Like sprintf but provides a pointer to malloc'd storage, which must
>>>>     be freed by the caller.  */
>>>>
>>>> +#ifndef asprintf
>>>>  extern int asprintf (char **, const char *, ...) ATTRIBUTE_PRINTF_2;
>>>>  #endif
>>>> +#endif
>>>>
>>>>  /* Like asprintf but allocates memory without fail. This works like
>>>>     xmalloc.  */
>>>
>>> Why is HAVE_DECL_ASPRINTF not defined?
>>>
>>> Ian