Fix build for FreeBSD (#1243)

CDRIVER-4465

- Some standard library features need __BSD_VISIBLE set to 1 to be enabled on FreeBSD
- Cmake does not properly detect res_search on FreeBSD. Since res_search has existed since 4.3 BSD (which is the predecessor of FreeBSD), it is safe to assume that this function will exist in libc on any version of FreeBSD.

Co-authored-by: Kevin Albertson <[email protected]>

Author: kkloberdanz

CMakeLists.txt

@@ -271,6 +271,12 @@ endif ()
 add_definitions (-D_XOPEN_SOURCE=700 -D_BSD_SOURCE -D_DEFAULT_SOURCE)
 list (APPEND CMAKE_REQUIRED_DEFINITIONS -D_XOPEN_SOURCE=700 -D_BSD_SOURCE -D_DEFAULT_SOURCE)
 
+# Enable non-standard features on FreeBSD with __BSD_VISIBLE=1
+if(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+   add_definitions (-D__BSD_VISIBLE=1)
+   list (APPEND CMAKE_REQUIRED_DEFINITIONS -D__BSD_VISIBLE=1)
+endif ()
+
 # https://opensource.apple.com/source/Libc/Libc-1439.40.11/gen/compat.5.auto.html
 # Non-POSIX extensions are required by `_SC_NPROCESSORS_ONLN`.
 if (CMAKE_SYSTEM_NAME MATCHES "Darwin")

build/cmake/FindResSearch.cmake

@@ -28,6 +28,21 @@ if (ENABLE_SRV STREQUAL ON OR ENABLE_SRV STREQUAL AUTO)
                set (MONGOC_HAVE_RES_NCLOSE 0)
             endif ()
          endif ()
+      elseif(CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
+         # On FreeBSD, the following line does not properly detect res_search,
+         # which is included in libc on FreeBSD:
+         # check_symbol_exists (res_search resolv.h MONGOC_HAVE_RES_SEARCH)
+         #
+         # Attempting to link with libresolv on FreeBSD will fail with this error:
+         # ld: error: unable to find library -lresolv
+         #
+         # Since res_search has existed since 4.3 BSD (which is the predecessor
+         # of FreeBSD), it is safe to assume that this function will exist in
+         # libc on FreeBSD.
+         set (MONGOC_HAVE_RES_SEARCH 1)
+         set (MONGOC_HAVE_RES_NSEARCH 0)
+         set (MONGOC_HAVE_RES_NDESTROY 0)
+         set (MONGOC_HAVE_RES_NCLOSE 0)
       else ()
          set (MONGOC_HAVE_RES_NSEARCH 0)
          set (MONGOC_HAVE_RES_NDESTROY 0)
@@ -48,10 +63,10 @@ else ()
    set (MONGOC_HAVE_RES_NSEARCH 0)
    set (MONGOC_HAVE_RES_NDESTROY 0)
    set (MONGOC_HAVE_RES_NCLOSE 0)
-   set (MONGOC_HAVE_RES_SEARCH 0)  
+   set (MONGOC_HAVE_RES_SEARCH 0)
 endif ()
 
-if (ENABLE_SRV STREQUAL ON AND NOT RESOLV_LIBRARIES)
+if (ENABLE_SRV STREQUAL ON AND NOT RESOLV_LIBRARIES AND NOT CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
    message (
       FATAL_ERROR
       "Cannot find libresolv or dnsapi. Try setting ENABLE_SRV=OFF")

src/libbson/tests/test-json.c

@@ -2113,8 +2113,8 @@ test_bson_json_double (void)
    BSON_ASSERT (BSON_ITER_HOLDS_DOUBLE (&iter));
    ASSERT_CMPDOUBLE (bson_iter_double (&iter), ==, 0.0);
 
-/* check that "x" is -0.0. signbit not available on Solaris or VS 2010 */
-#if !defined(__sun) && (!defined(_MSC_VER) || (_MSC_VER >= 1800))
+/* check that "x" is -0.0. signbit not available on Solaris, FreeBSD, or VS 2010 */
+#if !defined(__sun) && !defined(__FreeBSD__) && (!defined(_MSC_VER) || (_MSC_VER >= 1800))
    BSON_ASSERT (signbit (bson_iter_double (&iter)));
 #endif
 

src/libmongoc/src/mongoc/mongoc-client.c

@@ -14,7 +14,6 @@
  * limitations under the License.
  */
 
-
 #include <bson/bson.h>
 #include "mongoc-config.h"
 #ifdef MONGOC_HAVE_DNSAPI
@@ -25,6 +24,7 @@
 #else
 #if defined(MONGOC_HAVE_RES_NSEARCH) || defined(MONGOC_HAVE_RES_SEARCH)
 #include <netdb.h>
+#include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/nameser.h>
 #include <resolv.h>

src/libmongoc/src/mongoc/mongoc-counters-private.h

@@ -28,6 +28,7 @@
 #include <sys/sysinfo.h>
 #elif defined(__FreeBSD__) || defined(__NetBSD__) || defined(__DragonFly__) || \
    defined(__OpenBSD__)
+#include <sched.h>
 #include <sys/types.h>
 #include <sys/sysctl.h>
 #include <sys/param.h>