[Bug c/30426] New: Warning when using strndup

[Bug c/30426] New: Warning when using strndup

[raimund at cs dot auckland dot ac dot nz]

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The tiny test program below produces a warning (specifics commented in code
below). From my understanding, no warning should appear on compilation.
Current workaround: Warning disappears once line 2 (right after #include) is
uncommented.

Code:
---------------------------------------------------------------
#include <string.h>
// extern char *strndup (__const char *__string, size_t __n);

int main() {
  char *str="one two three",
       *one=0;

  // command below produces warning
  // "a.c:18: warning: assignment makes pointer from integer without a cast"
  // on openSuSE 10.0 (gcc (GCC) 4.0.2 20050901 (prerelease) (SUSE Linux))

  // command below produces warning
  // "a.c:18: warning: incompatible implicit declaration of built-in function
‘strndup’"
  // on openSuSE 10.2 (gcc (GCC) 4.1.2 20061115 (prerelease) (SUSE Linux))

  // warnings disappear when line 3 is uncommented.

  one = strndup(str,3);
}
---------------------------------------------------------------


-- 
           Summary: Warning when using strndup
           Product: gcc
           Version: 4.1.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: raimund at cs dot auckland dot ac dot nz


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30426

[Bug c/30426] Warning when using strndup

[pinskia at gcc dot gnu dot org]

------- Comment #2 from pinskia at gcc dot gnu dot org  2007-01-10 20:38 -------
Not a bug, strndup is a GNU (glibc) extension.  You have to use -D_GNU_SOURCE
when compiling.
The warning messages are correct as there is no prototype for strndup.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30426

[Bug c/30426] Warning when using strndup

[schwab at suse dot de]

------- Comment #1 from schwab at suse dot de  2007-01-10 20:37 -------
strndup is a GNU extension and is only declared in <string.h> when _GNU_SOURCE
is defined.


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schwab at suse dot de changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|                            |INVALID


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=30426