How does one build an x64 assembly program in OS X?

Question

I'm trying to build Hello World in x64 assembly on my Leopard MacBook Pro. It assembles fine, but I get this error when I try to link it: ld: symbol dyld_stub_binding_helper not defined (usually in crt1.o/dylib1.o/bundle1.o) for inferred architecture x86_64

I loaded it with ld -o hello64 hello64.o -lc

My assembler is Yasm.

EDIT: As far as I can tell, unlike for 32-bit code, you have to supply the stub helper yourself, and since I don't know how the 64-bit stub helper works I'll do as Bastien said and have GCC link it since it includes it's own stub helper.

Answer 1

You haven't specified an assembler. Personally, I had done this before using yasm assembler (and had written a blog post in that regard but since my blog has been down for a long time, I can't post a link). Basically, a hello world would be:

SECTION .data
   hello db 'hello, world', 10
   hellolen equ $ - hello

SECTION .text
   global start

start:
   mov rax, 0x2000004    ; sys_write
   mov rdi, 1            ; stdout 
   mov rsi, qword hello  ; string
   mov rdx, hellolen     ; length
   syscall
   mov rax, 0x2000001    ; sys_exit
   xor rdi, rdi          ; exit code
   syscall

Assembled with:

yasm -f macho64 file.asm
ld a.o
./a.out

Answer 2

Simply let GCC handle the linker invocation. Something like this:

gcc hello64.o -o hello64

Your assembly code will probably have to define a main symbol, or maybe start.

[Edit]

The reason why I'm suggesting this is that different platforms invoke the linker differently. If you see which arguments GCC passes to the linker with the --verbose command-line option, you will probably realize that it's complicated and implementation-dependent.