X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/21f5c1a62b4536ebc704de4d13791240ada6703a..refs/heads/master:/ftmacros.h

diff --git a/ftmacros.h b/ftmacros.h
index 4b272d5f..2e367a35 100644
--- a/ftmacros.h
+++ b/ftmacros.h
@@ -45,7 +45,12 @@
  * namespace to the maximum extent possible"?
  */
 #if defined(sun) || defined(__sun)
-  #define __EXTENSIONS__
+  /*
+   * On Solaris Clang defines __EXTENSIONS__ automatically.
+   */
+  #ifndef __EXTENSIONS__
+    #define __EXTENSIONS__
+  #endif
 
   /*
    * We also need to define _XPG4_2 in order to get
@@ -59,7 +64,7 @@
   /*
    * We need this to get the versions of socket functions that
    * use socklen_t.  Define it only if it's not already defined,
-   * so we don't get redefiniton warnings.
+   * so we don't get redefinition warnings.
    */
   #ifndef _XOPEN_SOURCE_EXTENDED
     #define _XOPEN_SOURCE_EXTENDED
@@ -83,23 +88,44 @@
    * least with HP's C compiler; hopefully doing so won't make it
    * *not* work with *un*-threaded code.
    */
-#elif defined(__linux__) || defined(linux) || defined(__linux)
+#else
+  /*
+   * Turn on _GNU_SOURCE to get everything GNU libc has to offer,
+   * including asprintf(), if we're using GNU libc.
+   *
+   * Unfortunately, one thing it has to offer is a strerror_r()
+   * that's not POSIX-compliant, but we deal with that in
+   * pcapint_fmt_errmsg_for_errno().
+   *
+   * We don't limit this to, for example, Linux and Cygwin, because
+   * this might, for example, be GNU/HURD or one of Debian's kFreeBSD
+   * OSes ("GNU/FreeBSD").
+   *
+   * Avoid redefining, same as below.
+   */
+  #ifndef _GNU_SOURCE
+    #define _GNU_SOURCE
+  #endif
+
   /*
-   * We can't turn _GNU_SOURCE on because some versions of GNU Libc
-   * will give the GNU version of strerror_r(), which returns a
-   * string pointer and doesn't necessarily fill in the buffer,
-   * rather than the standard version of strerror_r(), which
-   * returns 0 or an errno and always fills in the buffer.  We
-   * require both of the latter behaviors.
+   * We turn on both _DEFAULT_SOURCE and _BSD_SOURCE to try to get
+   * the BSD u_XXX types, such as u_int and u_short, defined.  We
+   * define _DEFAULT_SOURCE first, so that newer versions of GNU libc
+   * don't whine about _BSD_SOURCE being deprecated; we still have
+   * to define _BSD_SOURCE to handle older versions of GNU libc that
+   * don't support _DEFAULT_SOURCE.
    *
-   * So we try turning everything else on that we can.  This includes
-   * defining _XOPEN_SOURCE as 600, because we want to force crypt()
-   * to be declared on systems that use GNU libc, such as most Linux
-   * distributions.
+   * But, if it's already defined, don't define it, so that we don't
+   * get a warning of it being redefined if it's defined as, for
+   * example, 1.
    */
-  #define _POSIX_C_SOURCE 200809L
-  #define _XOPEN_SOURCE 600
-  #define _BSD_SOURCE
+  #ifndef _DEFAULT_SOURCE
+    #define _DEFAULT_SOURCE
+  #endif
+  /* Avoid redefining _BSD_SOURCE if it's already defined as for ex. 1 */
+  #ifndef _BSD_SOURCE
+    #define _BSD_SOURCE
+  #endif
 #endif
 
 #endif