user: 请从给定的汇编指令推导出C源代码:

```asm
<string_get_col>:
  endbr64
  push   %r14
  mov    %rdi,%r14
  mov    %rsi,%rdi
  push   %r13
  mov    %edx,%r13d
  push   %r12
  xor    %r12d,%r12d
  push   %rbp
  mov    %rcx,%rbp
  push   %rbx
  call   <string_get@plt>
  movsbl (%rax),%edi
  mov    %rax,%rbx
  cs nopw 0x0(%rax,%rax,1)
L188:
  mov    %rbp,%rsi
  call   <check_char_class@plt>
  test   %rax,%rax
  je     L232
L240:
  cmpb   $0x0,(%rbx)
  je     L247
  movsbl 0x1(%rbx),%edi
  mov    %rbp,%rsi
  add    $0x1,%rbx
  call   <check_char_class@plt>
  test   %rax,%rax
  jne    L240
L232:
  movzbl (%rbx),%eax
  test   %al,%al
  je     L247
  cmp    %r13d,%r12d
  je     L106
  cmp    $0x22,%al
  jne    L273
  jmp    L231
  nopl   (%rax)
L142:
  cmpb   $0x0,(%rbx)
  je     L247
  add    $0x1,%rbx
L273:
  movsbl (%rbx),%edi
  mov    %rbp,%rsi
  call   <check_char_class@plt>
  test   %rax,%rax
  je     L142
  movsbl (%rbx),%edi
  test   %dil,%dil
  je     L247
L105:
  add    $0x1,%r12d
  jmp    L188
  nop
L231:
  mov    %rbx,%rdx
  movzbl 0x1(%rbx),%eax
  add    $0x1,%rbx
  test   %al,%al
  je     L247
  cmp    $0x22,%al
  jne    L231
  test   %al,%al
  je     L247
  movsbl 0x2(%rdx),%edi
  lea    0x2(%rdx),%rbx
  jmp    L105
L65:
  movzbl 0x1(%rbx),%eax
  cmp    $0x22,%al
  je     L247
  test   %al,%al
  je     L247
  lea    0x1(%rbx),%rbp
  mov    %rbp,%r12
  jmp    L6
  cs nopw 0x0(%rax,%rax,1)
L191:
  cmp    $0x22,%al
  je     L129
  add    $0x1,%rbp
L6:
  movzbl 0x0(%rbp),%eax
  mov    %rbx,%rdx
  mov    %rbp,%rbx
  test   %al,%al
  jne    L191
L247:
  pop    %rbx
  mov    $0xffffffff,%eax
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L106:
  mov    %r14,%rdi
  lea    D5(%rip),%rsi
  call   <string_set@plt>
  movsbl (%rbx),%edi
  cmp    $0x22,%dil
  jne    L63
  jmp    L65
  xchg   %ax,%ax
L40:
  mov    %rbp,%rsi
  call   <check_char_class@plt>
  test   %rax,%rax
  jne    L70
  movsbl (%rbx),%esi
  mov    %r14,%rdi
  add    $0x1,%rbx
  call   <string_append_char@plt>
  movsbl (%rbx),%edi
L63:
  test   %dil,%dil
  jne    L40
L70:
  xor    %eax,%eax
L135:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  ret
L129:
  test   %al,%al
  je     L247
  cmp    %r12,%rdx
  jb     L70
  nopl   0x0(%rax,%rax,1)
L265:
  movsbl (%r12),%esi
  add    $0x1,%r12
  mov    %r14,%rdi
  call   <string_append_char@plt>
  cmp    %r12,%rbp
  jne    L265
  xor    %eax,%eax
  jmp    L135
```

tool_calls: name: disassemble_data
arguments: label: D5
data_type: string

tool: 

assistant: ```c
int string_get_col(struct string *dst, struct string const *src, unsigned col_no, char const *delim) {
  unsigned cur_col = 0;
  char const *strp = string_get(src);
  for (;;) {
    while (check_char_class(*strp, delim) && *strp)
      strp++;
    if (!*strp)
      return -1;
    if (cur_col == col_no)
      break;
    if (*strp == '"') {
      do {
        strp++;
      } while (*strp && *strp != '"');
      if (!*strp)
        return -1;
      strp++;
    } else {
      while (!check_char_class(*strp, delim) && *strp)
        strp++;
      if (!*strp)
        return -1;
    }
    cur_col++;
  }
  string_set(dst, "");
  if (*strp == '"') {
    if (strp[1] == '"' || !strp[1])
      return -1;
    char const *last;
    char const *first = strp + 1;
    do {
      last = strp;
      strp++;
    } while (*strp && *strp != '"');
    if (!*strp)
      return -1;
    while (first <= last)
      string_append_char(dst, *first++);
  } else {
    while (*strp && !check_char_class(*strp, delim))
      string_append_char(dst, *strp++);
  }
  return 0;
}
```