clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG -I. -Iyajl -Ibson -Imongoc -DBSON_COMPILATION -DMONGOC_COMPILATION -I/usr/local/opt/openssl/include -Wno-deprecated-declarations -DMONGOC_HAVE_SASL_CLIENT_DONE -DBSON_EXTRA_ALIGN -I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include   -Wall -pedantic -fPIC  -Wall -mtune=core2 -g -O2  -c mongoc/mongoc-matcher-op.c -o mongoc/mongoc-matcher-op.o
mongoc/mongoc-matcher-op.c:1120:7: warning: use of GNU statement expression extension [-Wgnu-statement-expression]
      _ignore_value(bson_append_iter (bson, op->compare.path, -1, &op->compare.iter));
      ^
mongoc/mongoc-util-private.h:34:29: note: expanded from macro '_ignore_value'
# define _ignore_value(x) (({ __typeof__ (x) __x = (x); (void) __x; }))
                            ^
mongoc/mongoc-matcher-op.c:1156:10: warning: use of GNU statement expression extension [-Wgnu-statement-expression]
         _ignore_value (bson_append_iter (&child, str, -1, &op->compare.iter));
         ^
mongoc/mongoc-util-private.h:34:29: note: expanded from macro '_ignore_value'
# define _ignore_value(x) (({ __typeof__ (x) __x = (x); (void) __x; }))
   
                            ^

clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG -I. -Iyajl -Ibson -Imongoc -DBSON_COMPILATION -DMONGOC_COMPILATION -I/usr/local/opt/openssl/include -Wno-deprecated-declarations -DMONGOC_HAVE_SASL_CLIENT_DONE -DBSON_EXTRA_ALIGN -I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include   -Wall -pedantic -fPIC  -Wall -mtune=core2 -g -O2  -c mongoc/mongoc-write-command.c -o mongoc/mongoc-write-command.o
mongoc/mongoc-write-command.c:1129:16: warning: use of GNU statement expression extension [-Wgnu-statement-expression]
               _ignore_value (bson_append_iter (gle, "upserted", 8, &subiter));
               ^
mongoc/mongoc-util-private.h:34:29: note: expanded from macro '_ignore_value'
# define _ignore_value(x) (({ __typeof__ (x) __x = (x); (void) __x; }))
                            ^
mongoc/mongoc-write-command.c:1132:16: warning: use of GNU statement expression extension [-Wgnu-statement-expression]
               _ignore_value (bson_append_iter (gle, "upserted", 8, &subiter));
               ^
mongoc/mongoc-util-private.h:34:29: note: expanded from macro '_ignore_value'
# define _ignore_value(x) (({ __typeof__ (x) __x = (x); (void) __x; }))
                            ^

clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG -I. -Iyajl -Ibson -Imongoc -DBSON_COMPILATION -DMONGOC_COMPILATION -I/usr/local/opt/openssl/include -Wno-deprecated-declarations -DMONGOC_HAVE_SASL_CLIENT_DONE -DBSON_EXTRA_ALIGN -I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include   -Wall -pedantic -fPIC  -Wall -mtune=core2 -g -O2  -c mongoc/mongoc-crypto-openssl.c -o mongoc/mongoc-crypto-openssl.o
mongoc/mongoc-rand-common-crypto.c:45:7: warning: ISO C requires a translation unit to contain at least one declaration [-Wempty-translation-unit]
#endif
      ^
1 warning generated.