clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG -I. -Iyajl -Ibson -Imongoc -include apple.h -include mlfeatures.h -I/opt/csw/include -DBSON_COMPILATION -DMONGOC_COMPILATION  -I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include   -Wall -pedantic -Wno-deprecated-declarations -fPIC  -Wall -mtune=core2 -g -O2  -c cursor.c -o cursor.o
cursor.c:72:25: warning: passing 'const char *' to parameter of type 'void *' discards qualifiers [-Wincompatible-pointer-types-discards-qualifiers]
      if(str) bson_free(str);
                        ^~~
bson/bson-memory.h:60:36: note: passing argument to parameter 'mem' here
void  bson_free           (void   *mem);

clang -I/Library/Frameworks/R.framework/Resources/include -DNDEBUG -I. -Iyajl -Ibson -Imongoc -include apple.h -include mlfeatures.h -I/opt/csw/include -DBSON_COMPILATION -DMONGOC_COMPILATION  -I/usr/local/include -I/usr/local/include/freetype2 -I/opt/X11/include   -Wall -pedantic -Wno-deprecated-declarations -fPIC  -Wall -mtune=core2 -g -O2  -c mongoc/mongoc-async-cmd.c -o mongoc/mongoc-async-cmd.o
mongoc/mongoc-async-cmd.c:286:32: warning: arithmetic on a pointer to void is a GNU extension [-Wpointer-arith]
         acmd->iovec->iov_base += bytes;
         ~~~~~~~~~~~~~~~~~~~~~ ^