Task #3696: Added HAVE_STRNLEN, because strnlen() is GNU only

CMake/LofarGeneral.cmake

@@ -126,6 +126,18 @@ if(NOT DEFINED LOFAR_GENERAL_INCLUDED)
       }" HAVE_GETPROTOBYNAME_R)
   endif(HAVE_NETDB_H)
 
+  ## --------------------------------------------------------------------------
+  ## Define `STRNLEN', if the strnlen() function exists.
+  ## --------------------------------------------------------------------------
+  check_c_source_compiles("
+    #include <string.h>
+    #include <stdio.h>
+    int main() {
+      char *s = \"test\";
+      int i = 3;
+      unsigned l = strnlen(s,i);
+    }" HAVE_STRNLEN)
+
   ## --------------------------------------------------------------------------
   ## Define custom target 'check', so that we can do 'make check', like we did
   ## with the GNU Autotools. Tests should be added with lofar_add_test().

lofar_config.h.cmake

@@ -172,3 +172,6 @@
 
 /* Define to 1 if you have a declaration for the `getprotobyname_r' function. */
 #cmakedefine HAVE_GETPROTOBYNAME_R 1
+
+/* Define to 1 if you have a declaration for the `strnlen' function. */
+#cmakedefine HAVE_STRNLEN 1