user: 请从给定的汇编指令推导出C源代码:

```asm
<opt_strcat>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  sub    $0x50,%rsp
  mov    %rdi,-0x48(%rbp)
  mov    %rsi,-0x50(%rbp)
  lea    D17(%rip),%rax
  mov    %rax,-0x10(%rbp)
  mov    -0x10(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,-0x28(%rbp)
  mov    -0x50(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,-0x24(%rbp)
  mov    -0x24(%rbp),%eax
  add    $0x1,%eax
  mov    %eax,%edi
  call   <malloc@plt>
  mov    %rax,-0x8(%rbp)
  mov    -0x50(%rbp),%rdx
  mov    -0x8(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcpy@plt>
  mov    -0x8(%rbp),%rax
  mov    %rax,-0x20(%rbp)
  mov    -0x20(%rbp),%rax
  mov    $0x2,%edx
  lea    D15(%rip),%rcx
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strncmp@plt>
  test   %eax,%eax
  jne    L18
  addq   $0x2,-0x20(%rbp)
L18:
  movl   $0x0,-0x34(%rbp)
  mov    -0x28(%rbp),%edx
  mov    -0x10(%rbp),%rcx
  mov    -0x20(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strncmp@plt>
  mov    %eax,-0x30(%rbp)
  jmp    L61
L48:
  mov    -0x28(%rbp),%eax
  cltq
  add    %rax,-0x20(%rbp)
  addl   $0x1,-0x34(%rbp)
  mov    -0x28(%rbp),%edx
  mov    -0x10(%rbp),%rcx
  mov    -0x20(%rbp),%rax
  mov    %rcx,%rsi
  mov    %rax,%rdi
  call   <strncmp@plt>
  mov    %eax,-0x30(%rbp)
L61:
  cmpl   $0x0,-0x30(%rbp)
  je     L48
  cmpl   $0x0,-0x34(%rbp)
  jne    L42
  mov    -0x20(%rbp),%rdx
  mov    -0x48(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcat@plt>
  jmp    L35
L42:
  movb   $0x0,-0x35(%rbp)
  mov    -0x48(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  movslq %eax,%rdx
  mov    -0x48(%rbp),%rax
  add    %rdx,%rax
  mov    %rax,-0x18(%rbp)
  movl   $0x0,-0x2c(%rbp)
  jmp    L19
L2:
  subq   $0x1,-0x18(%rbp)
  mov    -0x18(%rbp),%rax
  movzbl (%rax),%eax
  mov    %al,-0x35(%rbp)
  cmpb   $0x2f,-0x35(%rbp)
  jne    L19
  mov    -0x18(%rbp),%rax
  movb   $0x0,(%rax)
  addl   $0x1,-0x2c(%rbp)
L19:
  mov    -0x2c(%rbp),%eax
  cmp    -0x34(%rbp),%eax
  jle    L2
  mov    -0x48(%rbp),%rax
  lea    D21(%rip),%rdx
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcat@plt>
  mov    -0x20(%rbp),%rdx
  mov    -0x48(%rbp),%rax
  mov    %rdx,%rsi
  mov    %rax,%rdi
  call   <strcat@plt>
L35:
  mov    -0x8(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  nop
  leave
  ret
```

tool_calls: name: parse_data
arguments: data_tag: D17
datatype: string
name: parse_data
arguments: data_tag: D15
datatype: string
name: parse_data
arguments: data_tag: D21
datatype: string

tool: D17: ../

tool: D15: ./

tool: D21: /

assistant: ```c
void opt_strcat(char *base, char *tar) {
  const char *dlm = "../";
  int dlen = strlen(dlm);
  int len = strlen(tar);
  char *clone = (char *)malloc(len + 1);
  strcpy(clone, tar);
  char *index = clone;
  if (strncmp(index, "./", 2) == 0)
    index += 2;
  int amount = 0;
  int cmp = strncmp(index, dlm, dlen);
  for (; cmp == 0;) {
    index += dlen;
    amount++;
    cmp = strncmp(index, dlm, dlen);
  }
  if (amount == 0) {
    strcat(base, index);
  } else {
    char cur = 0;
    char *zero = base + strlen(base);
    for (int cnt = 0; cnt <= amount;) {
      cur = *(--zero);
      if (cur == '/') {
        *zero = '\0';
        cnt++;
      }
    }
    strcat(base, "/");
    strcat(base, index);
  }
  free(clone);
  return;
}
```