user: Demonstrate the C code that generates the assembly output below:

```asm
<substr_combine>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x58,%rsp
  mov    %rdi,-0x68(%rbp)
  mov    %rsi,-0x70(%rbp)
  mov    %edx,-0x74(%rbp)
  mov    %rcx,-0x80(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  lea    D12(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  movl   $0x0,-0x60(%rbp)
  movq   $0x0,-0x50(%rbp)
  movl   $0x0,-0x60(%rbp)
  jmp    L36
L41:
  mov    -0x60(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x70(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  mov    %eax,%edi
  call   <substr_len@plt>
  add    %rax,-0x50(%rbp)
  mov    -0x50(%rbp),%rax
  mov    %rax,%rsi
  lea    D26(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  addl   $0x1,-0x60(%rbp)
L36:
  mov    -0x60(%rbp),%eax
  cmp    -0x74(%rbp),%eax
  jb     L41
  lea    D2(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  mov    -0x50(%rbp),%rax
  cmp    -0x80(%rbp),%rax
  jb     L76
  lea    D5(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  mov    $0xffffffff,%eax
  jmp    L8
L76:
  movl   $0x0,-0x5c(%rbp)
  movl   $0x0,-0x58(%rbp)
  movl   $0x0,-0x60(%rbp)
  jmp    L66
L93:
  mov    %rsp,%rax
  mov    %rax,%rbx
  mov    -0x60(%rbp),%eax
  lea    0x0(,%rax,4),%rdx
  mov    -0x70(%rbp),%rax
  add    %rdx,%rax
  mov    (%rax),%eax
  mov    %eax,-0x54(%rbp)
  mov    -0x54(%rbp),%eax
  mov    %eax,%edi
  call   <substr_size@plt>
  mov    %eax,-0x58(%rbp)
  mov    -0x58(%rbp),%eax
  mov    %eax,%edx
  sub    $0x1,%rdx
  mov    %rdx,-0x48(%rbp)
  mov    %eax,%edx
  mov    %rdx,%r12
  mov    $0x0,%r13d
  mov    %eax,%edx
  mov    %rdx,%r14
  mov    $0x0,%r15d
  mov    %eax,%edx
  mov    $0x10,%eax
  sub    $0x1,%rax
  add    %rdx,%rax
  mov    $0x10,%esi
  mov    $0x0,%edx
  div    %rsi
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L71:
  cmp    %rdx,%rsp
  je     L17
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L71
L17:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L25
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L25:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x40(%rbp)
  mov    -0x58(%rbp),%edx
  mov    -0x54(%rbp),%ecx
  mov    -0x40(%rbp),%rax
  mov    %ecx,%esi
  mov    %rax,%rdi
  call   <substr_assemble@plt>
  mov    -0x5c(%rbp),%edx
  mov    -0x68(%rbp),%rax
  lea    (%rdx,%rax,1),%rcx
  mov    -0x58(%rbp),%edx
  mov    -0x40(%rbp),%rax
  mov    %rax,%rsi
  mov    %rcx,%rdi
  call   <strcpy_limit@plt>
  add    %eax,-0x5c(%rbp)
  mov    -0x58(%rbp),%ecx
  mov    -0x54(%rbp),%edx
  mov    -0x5c(%rbp),%eax
  mov    %eax,%esi
  lea    D30(%rip),%rax
  mov    %rax,%rdi
  mov    $0x0,%eax
  call   <printf@plt>
  mov    %rbx,%rsp
  addl   $0x1,-0x60(%rbp)
L66:
  mov    -0x60(%rbp),%eax
  cmp    -0x74(%rbp),%eax
  jb     L93
  lea    D46(%rip),%rax
  mov    %rax,%rdi
  call   <puts@plt>
  mov    -0x68(%rbp),%rdx
  mov    -0x50(%rbp),%rax
  add    %rdx,%rax
  movb   $0x0,(%rax)
  mov    -0x5c(%rbp),%eax
L8:
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L99
  call   <__stack_chk_fail@plt>
L99:
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

tool_calls: name: unpack_data
arguments: data_tag: D12
type_infered: string
name: unpack_data
arguments: data_tag: D26
type_infered: string
name: unpack_data
arguments: data_tag: D2
type_infered: string
name: unpack_data
arguments: data_tag: D5
type_infered: string
name: unpack_data
arguments: data_tag: D30
type_infered: string
name: unpack_data
arguments: data_tag: D46
type_infered: string

tool: D12: 1111

tool: D26: total_len %d


tool: D2: 22222

tool: D5: 33333

tool: D30: offs %d, id%d, max %d


tool: D46: 44444

assistant: ```c
int substr_combine(char *dst, int *substr_ids, unsigned int n_ints, size_t dst_sz) {
  printf("1111\n");
  unsigned int i = 0;
  size_t total_len = 0;
  for (i = 0; i < n_ints; ++i) {
    total_len += substr_len(substr_ids[i]);
    printf("total_len %d\n", total_len);
  }
  printf("22222\n");
  if (total_len >= dst_sz) {
    printf("33333\n");
    return -1;
  }
  unsigned int offs = 0;
  unsigned int max = 0;
  for (i = 0; i < n_ints; ++i) {
    int id = substr_ids[i];
    max = substr_size(id);
    char src[max];
    substr_assemble(src, id, max);
    offs += strcpy_limit(&dst[offs], src, max);
    printf("offs %d, id%d, max %d\n", offs, id, max);
  }
  printf("44444\n");
  dst[total_len] = '\0';
  return offs;
}
```