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 <i...@google.com> wrote: > On Fri, May 1, 2015 at 4:45 PM, Yunlian Jiang <yunl...@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 <i...@google.com> wrote: >>> On Tue, Apr 28, 2015 at 2:59 PM, Yunlian Jiang <yunl...@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
