ropnroll is an helper library, designed for use in OS X exploits. I am using it for my kernel stuff PoCs, but may be useful for other purposes as well.
The library is in early stages and there is much more to add and modify. For now it provides:

• Some kind of Mach-O parsing (to be improved!)
• Useful functions for ROP gadgets, i.e. find a single gadget or a group of gadgets in memory, dump gadgets in a human-readable format, find symbols in memory. (to be improved!)
• There are also various functions to be only used with kernel exploitation, find unslid KEXTs base address, find unslid kernel base (for symbol and gadgets resolution), find kernel slide (via kas_info with root privileges) (to be improved!)

ropnroll is not very useful in its current state, it needs to be improved further. I will add more Mach-O parsing helpers, more ROP helpers (gadget macros, mapped images analysis, etc.), and also other kernel-exploitation-oriented stuff.

Simply include the ropnroll/ directory (found inside src/ in this repo) in your project. Link against capstone.
You will need to #include the ropnroll.h and ropnroll_macros.h files to use the library.

You need capstone to compile ropnroll. You can find the correct capstone dylib (libcapstone.3.dylib) the lib/ directory in this repository. The fat dylib is for both x86 and x64. You may need to manually replace the one located in /usr/local/lib if it doesn't compile.

ropnroll provides functions for Mach-O binaries analysis, inside the ropnroll/macho/ subdirectory.
These functions operate on gadget_map_t structures (note that the name will likely change in future), which are simple structs to hold together a mapped file and its size.
You can create a gadget_map_t for a file by simply calling rnr_map_file_with_path with the file path as an argument.

Once you have a map, use that to perform Mach-O analysis on the file. Example:

gadget_map_t *map=rnr_map_file_with_path("/System/Library/Kernels/kernel"); //map kernel

struct symtab_command *symcmd = find_symbol_table_in_map(map);
printf("Kernel has %d symbols defined.\n", symcmd->nsyms);

Obviously, more analysis function will be added to ropnroll soon!

ropnroll is primarily an exploitation library. So it provides a set of functions to discover and handle ROP gadgets to be used in ROP chains after successful stack pivoting.

You can find various macros inside ropnroll/gadgets/rnr_gadgets.h. These are direct gadgets, meaning you can use these macros to directly find that sequence in a gadget_map_t. They are already there for you!
You can obviously use functions like rnr_locate_gadget_in_map and rnr_locate_gadget_group_in_map to find your own byte sequences.

gadget_map_t *map=rnr_map_file_with_path("/System/Library/Kernels/kernel"); //map kernel

char nop_gadget[] = {0x90, 0xC3};
printf("NOP gadget @: %#llx\n", rnr_locate_kernel_base(map) + rnr_locate_gadget_in_map(map, nop_gadget, sizeof(nop_gadget)));

Thanks to @qwertyoruiop for help and his swag libraries (lsym and libxnuexp)!

You can contribute by issuing pull requests, and that would be very appreciated!