user: 下面的汇编指令对应的C源代码是什么：

```asm
<parse_argv>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  sub    $0x18,%rsp
  mov    %rdi,%r12
  mov    %rsi,%r14
  call   <strlen@plt>
  mov    %eax,%edi
  mov    $0x8,%esi
  call   <calloc@plt>
  mov    %rax,%r15
  movl   $0x0,(%r14)
  mov    %r12,(%rax)
  mov    %r12,%rbp
L185:
  movsbl 0x0(%rbp),%edi
  call   <isspace@plt>
  test   %rax,%rax
  je     L90
  add    $0x1,%rbp
  jmp    L185
L90:
  movl   $0x0,0xc(%rsp)
  mov    $0x0,%r13d
  jmp    L9
L39:
  movsbl %bpl,%edi
  call   <isspace@plt>
  cmpl   $0x0,0xc(%rsp)
  sete   %dl
  test   %rax,%rax
  je     L173
  test   %dl,%dl
  jne    L153
L173:
  cmp    $0x5c,%bpl
  jne    L259
  add    $0x1,%r13d
  jmp    L269
L96:
  add    $0x1,%rbx
L194:
  movsbl (%rbx),%edi
  call   <isspace@plt>
  test   %rax,%rax
  jne    L96
  cmpb   $0x0,(%rbx)
  jne    L84
L183:
  mov    %r15,%rax
  add    $0x18,%rsp
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
L84:
  mov    $0x0,%r13d
L269:
  mov    %rbx,%rbp
L9:
  lea    0x1(%rbp),%rbx
  movzbl 0x0(%rbp),%ebp
  test   %bpl,%bpl
  jne    L39
  test   %r13d,%r13d
  je     L162
L196:
  mov    %r13d,%edx
  add    %r12,%rdx
  mov    %r12,%rax
L42:
  add    $0x1,%rax
  movb   $0x5c,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L42
  lea    -0x1(%r13),%eax
  lea    0x1(%r12,%rax,1),%rax
  lea    0x1(%rax),%r12
  movb   $0x0,(%rax)
  mov    (%r14),%eax
  add    $0x1,%eax
  mov    %eax,(%r14)
  cltq
  mov    %r12,(%r15,%rax,8)
  test   %bpl,%bpl
  jne    L194
  jmp    L183
L259:
  cmp    $0x22,%bpl
  je     L226
  test   %r13d,%r13d
  je     L93
L24:
  lea    -0x1(%r13),%eax
  lea    0x1(%r12,%rax,1),%rdx
  mov    %r12,%rax
L151:
  add    $0x1,%rax
  movb   $0x5c,-0x1(%rax)
  cmp    %rdx,%rax
  jne    L151
  lea    -0x1(%r13),%eax
  lea    0x1(%r12,%rax,1),%r12
  mov    $0x0,%r13d
  test   %bpl,%bpl
  je     L269
L93:
  mov    %bpl,(%r12)
  lea    0x1(%r12),%r12
  mov    $0x0,%r13d
  jmp    L269
L226:
  test   $0x1,%r13b
  jne    L86
  movzbl %dl,%eax
  mov    %eax,0xc(%rsp)
  sar    %r13d
  je     L269
  mov    $0x0,%ebp
  jmp    L24
L153:
  test   %r13d,%r13d
  jne    L196
  lea    0x1(%r12),%rdx
  movb   $0x0,(%r12)
  mov    (%r14),%eax
  add    $0x1,%eax
  mov    %eax,(%r14)
  cltq
  mov    %rdx,(%r15,%rax,8)
  mov    %rdx,%r12
  jmp    L194
L162:
  movb   $0x0,(%r12)
  mov    (%r14),%eax
  add    $0x1,%eax
  mov    %eax,(%r14)
  cltq
  add    $0x1,%r12
  mov    %r12,(%r15,%rax,8)
  jmp    L183
L86:
  sar    %r13d
  jne    L24
  jmp    L93
```

assistant: ```c
char **parse_argv(char *cmdline, int *argc) {
  char **result = calloc(strlen(cmdline), sizeof(char *));
  char *output = cmdline;
  char c;
  int nb = 0;
  int iq = 0;
  *argc = 0;
  result[0] = output;
  while (isspace(*cmdline))
    cmdline++;
  do {
    c = *cmdline++;
    if (!c || (isspace(c) && !iq)) {
      while (nb) {
        *output++ = '\\';
        nb--;
      }
      *output++ = 0;
      result[++*argc] = output;
      if (!c)
        return result;
      while (isspace(*cmdline))
        cmdline++;
      if (!*cmdline)
        return result;
      continue;
    }
    if (c == '\\')
      ++nb;
    else {
      if (c == '"') {
        if (!(nb & 1)) {
          iq = !iq;
          c = 0;
        }
        nb = nb >> 1;
      }
      while (nb) {
        *output++ = '\\';
        nb--;
      }
      if (c)
        *output++ = c;
    }
  } while (1);
}
```