user: 请显示与下面列出的汇编代码相匹配的C语言实现:

```asm
<sdb_realpath>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r12
  push   %rbx
  sub    $0x50,%rsp
  mov    %rdi,-0x58(%rbp)
  mov    %fs:0x28,%rax
  mov    %rax,-0x28(%rbp)
  xor    %eax,%eax
  cmpq   $0x0,-0x58(%rbp)
  jne    L9
  mov    $0x0,%eax
  jmp    L7
L9:
  mov    -0x58(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  cmp    $0x1,%eax
  jle    L79
  mov    -0x58(%rbp),%rax
  movzbl (%rax),%eax
  cmp    $0x7e,%al
  jne    L79
  mov    -0x58(%rbp),%rax
  add    $0x1,%rax
  movzbl (%rax),%eax
  cmp    $0x2f,%al
  jne    L79
  mov    %rsp,%rax
  mov    %rax,%r12
  mov    $0x0,%eax
  call   <sdb_get_homedir@plt>
  mov    %rax,-0x48(%rbp)
  cmpq   $0x0,-0x48(%rbp)
  je     L45
  mov    -0x48(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  mov    %eax,%ebx
  jmp    L0
L45:
  mov    $0x0,%ebx
L0:
  mov    -0x58(%rbp),%rax
  mov    %rax,%rdi
  call   <strlen@plt>
  lea    (%rbx,%rax,1),%esi
  movslq %esi,%rax
  sub    $0x1,%rax
  mov    %rax,-0x40(%rbp)
  movslq %esi,%rax
  mov    %rax,-0x70(%rbp)
  movq   $0x0,-0x68(%rbp)
  movslq %esi,%rax
  mov    %rax,%r14
  mov    $0x0,%r15d
  movslq %esi,%rax
  mov    $0x10,%edx
  sub    $0x1,%rdx
  add    %rdx,%rax
  mov    $0x10,%ebx
  mov    $0x0,%edx
  div    %rbx
  imul   $0x10,%rax,%rax
  mov    %rax,%rcx
  and    $0xfffffffffffff000,%rcx
  mov    %rsp,%rdx
  sub    %rcx,%rdx
L124:
  cmp    %rdx,%rsp
  je     L133
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L124
L133:
  mov    %rax,%rdx
  and    $0xfff,%edx
  sub    %rdx,%rsp
  mov    %rax,%rdx
  and    $0xfff,%edx
  test   %rdx,%rdx
  je     L54
  and    $0xfff,%eax
  sub    $0x8,%rax
  add    %rsp,%rax
  orq    $0x0,(%rax)
L54:
  mov    %rsp,%rax
  add    $0x0,%rax
  mov    %rax,-0x38(%rbp)
  cmpq   $0x0,-0x48(%rbp)
  jne    L42
  mov    $0x0,%eax
  jmp    L126
L42:
  mov    -0x58(%rbp),%rax
  lea    0x2(%rax),%rcx
  mov    -0x48(%rbp),%rdx
  mov    -0x38(%rbp),%rax
  mov    %rcx,%r8
  mov    %rdx,%rcx
  lea    D2(%rip),%rdx
  mov    %rax,%rdi
  call   <snprintf@plt>
  mov    -0x38(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <realpath@plt>
  mov    %rax,-0x30(%rbp)
  mov    -0x48(%rbp),%rax
  mov    %rax,%rdi
  call   <free@plt>
  mov    -0x30(%rbp),%rax
L126:
  mov    %r12,%rsp
  jmp    L7
L79:
  mov    -0x58(%rbp),%rax
  mov    $0x0,%esi
  mov    %rax,%rdi
  call   <realpath@plt>
L7:
  mov    -0x28(%rbp),%rdx
  sub    %fs:0x28,%rdx
  je     L64
  call   <__stack_chk_fail@plt>
L64:
  lea    -0x20(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
```

tool_calls: name: extract_symbolic_data
arguments: label: D2
type_infered: string

tool: D2: %s/%s

assistant: ```c
char *sdb_realpath(const char *path) {
  if (!path)
    return NULL;
  if ((strlen(path) >= 2) && (path[0] == '~') && (path[1] == '/')) {
    char *homedir = sdb_get_homedir();
    char tmp[(homedir ? strlen(homedir) : 0) + strlen(path)];
    char *ret;
    if (!homedir)
      return NULL;
    snprintf(tmp, sizeof(tmp), "%s/%s", homedir, path + 2);
    ret = realpath(tmp, NULL);
    free(homedir);
    return ret;
  }
  return realpath(path, NULL);
}
```