.section        rodata
.LC0: .string "failed to allocate linked list"
.LC1: .string "failed to initialize linked list"

.section        data
.LC2: .string "my example string\n"

        .text
        .globl  main


# struct linked_list
# {
#   struct linked_item *first;
#   size_t length;
# }
#
# struct linked_item
# {
#   void *ptr;
#   struct linked_item *prev;
#   struct linked_item *next;
# }

# calling convention
# rdi                => struct linked_list*
# rsi, rdx, r10-r15  => 8 params.
# rax                => return value
# param. registers are callee-preserved, including rbp if necessary

# void free_linked_list (struct linked_list *ptr)
free_linked_list:
        call free@PLT
        ret

.macro iterate_last_item_rdx_rcx
        decq %rcx
        jo .Literate_last_item_rdx_rcx__loop_cont
        jmp .Literate_last_item_rdx_rcx__loop_cond
.Literate_last_item_rdx_rcx__loop:
        movq 0x10(%rdx), %rdx
        decq %rcx
.Literate_last_item_rdx_rcx__loop_cond:
        testq %rcx, %rcx
        jnz .Literate_last_item_rdx_rcx__loop
.Literate_last_item_rdx_rcx__loop_cont:
.endm

.macro alloc_linked_list_rdi_rax
        movq $0x10, %rdi
        call malloc@PLT
        testq %rax, %rax
        jz .Lalloc_linked_list_rdi_rax__cont
        movq $0x0, 0x0(%rax)
        movq $0x0, 0x8(%rax)
.Lalloc_linked_list_rdi_rax__cont:
.endm

.macro alloc_linked_list_item_rdi_rax
        movq $24, %rdi
        call malloc@PLT
        testq %rax, %rax
        leaq 0x1a(%rip), %r10
        jmp *%r10
#       jz .Lalloc_linked_list_item_rdi_rax__cont
        movq $0xA, 0x0(%rax)  # void *data
        movq $0x0, 0x8(%rax)  # struct linked_list_item *prev
        movq $0x0, 0x10(%rax) # struct linked_list_item *next
#.Lalloc_linked_list_item_rdi_rax__cont:
.endm


# bool add_linked_list_item (struct linked_list *ptr, void *data)
        .type add_linked_list_item, @function
add_linked_list_item:
        pushq %rdi
        pushq %rdx
        pushq %rbp
        subq $0x8, %rsp

        movq %rdx, 0x0(%rsp)
        xorq %rcx, %rcx
        movq 0x8(%rdi), %rcx  # length
        movq 0x0(%rdi), %rdx  # start item
        iterate_last_item_rdx_rcx

        movq %rdi, %rbp
        alloc_linked_list_item_rdi_rax
        movq %rbp, %rdi

        movq %rax, 0x10(%rdx)
        movq %rdx, 0x8(%rax)
        movq 0x0(%rsp), %rbp
        movq %rbp, 0x0(%rax)

        addq $0x8, %rsp
        popq %rbp
        popq %rdx
        popq %rdi
        ret

# bool init_linked_list (struct linked_list *ptr)
        .type init_linked_list, @function
init_linked_list:
        pushq %rdi
        pushq %rbp
        movb $0x1, %al
        movq 0x0(%rdi), %rbp
        testq %rbp, %rbp
        jnz .Linit_linked_list__ret
        movq %rdi, %rbp
        alloc_linked_list_item_rdi_rax
        testq %rax, %rax
        jz .Linit_linked_list__cont
        incq 0x8(%rbp)
.Linit_linked_list__cont:
        movq %rax, 0x0(%rbp)
        xorb %al, %al
.Linit_linked_list__ret:
        popq %rbp
        popq %rdi
        ret

# struct linked_list *alloc_linked_list (void)
        .type alloc_linked_list, @function
alloc_linked_list:
        push %rdi
        alloc_linked_list_rdi_rax
        pop %rdi
        ret

        .type main, @function
main:
        subq $0x8, %rsp
        call alloc_linked_list
        testq %rax, %rax
        jnz .Lmain__alloc_cont
        leaq .LC0(%rip), %rdi
        call puts@PLT
        movq $0x1, %rax
        jmp .Lmain__ret
.Lmain__alloc_cont:
        movq %rax, 0x0(%rsp)
        movq %rax, %rdi
        call init_linked_list
        testq %rax, %rax
        jnz .Lmain__init_cont
        leaq .LC1(%rip), %rdi
        call puts@PLT
        movq $0x1, %rax
        jmp .Lmain__ret
.Lmain__init_cont:
        movq 0x0(%rsp), %rdi
        leaq .LC2(%rip), %rdx
        call add_linked_list_item

.Lmain__ret:
        addq $0x8, %rsp
        ret