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

```asm
<realpath>:
  endbr64
  push   %rbp
  mov    %rsp,%rbp
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbx
  sub    $0x58,%rsp
  mov    %rdi,%r13
  mov    %rsi,%r15
  mov    %fs:0x28,%rax
  mov    %rax,-0x38(%rbp)
  xor    %eax,%eax
  mov    D16(%rip),%rax
  mov    (%rax),%eax
  mov    %eax,-0x6c(%rbp)
  cltq
  mov    %rax,-0x50(%rbp)
  lea    0xf(%rax,%rax,1),%rax
  mov    %rax,%rcx
  and    $0xfffffffffffffff0,%rcx
  and    $0xfffffffffffff000,%rax
  mov    %rsp,%rdx
  sub    %rax,%rdx
L206:
  cmp    %rdx,%rsp
  je     L225
  sub    $0x1000,%rsp
  orq    $0x0,0xff8(%rsp)
  jmp    L206
L225:
  mov    %rcx,%rax
  and    $0xfff,%eax
  sub    %rax,%rsp
  test   %rax,%rax
  je     L274
  orq    $0x0,-0x8(%rsp,%rax,1)
L274:
  mov    %rsp,-0x60(%rbp)
  test   %r13,%r13
  je     L212
  movq   $0x0,-0x78(%rbp)
  test   %r15,%r15
  je     L158
L211:
  movzbl 0x0(%r13),%eax
  test   %al,%al
  je     L434
  cmp    $0x2f,%al
  je     L73
  test   %r15,%r15
  je     L148
  mov    D16(%rip),%rax
  mov    (%rax),%esi
  mov    %r15,%rdi
  call   <getcwd@plt>
  test   %rax,%rax
  je     L194
L148:
  mov    %r15,%rdi
  call   <strlen@plt>
  lea    (%r15,%rax,1),%r14
  cmp    $0x1,%rax
  cmovbe %r15,%r14
L240:
  movl   $0x0,-0x54(%rbp)
  movl   $0x0,-0x58(%rbp)
  lea    -0x3c(%rbp),%rax
  mov    %rax,-0x48(%rbp)
  jmp    L375
L212:
  mov    D102(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  mov    %r13,%rax
  jmp    L282
L158:
  mov    -0x6c(%rbp),%edi
  call   <malloc@plt>
  mov    %rax,%r15
  test   %rax,%rax
  je     L282
  mov    %rax,-0x78(%rbp)
  jmp    L211
L434:
  movb   $0x0,(%r15)
  mov    D23(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
L382:
  mov    -0x78(%rbp),%rdi
  call   <free@plt>
  mov    $0x0,%eax
L282:
  mov    -0x38(%rbp),%rdx
  sub    %fs:0x28,%rdx
  jne    L116
  lea    -0x28(%rbp),%rsp
  pop    %rbx
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  pop    %rbp
  ret
L194:
  movb   $0x2e,(%r15)
  movb   $0x0,0x1(%r15)
  jmp    L382
L73:
  mov    %r15,%r14
  jmp    L240
L226:
  add    $0x1,%r13
L375:
  movzbl 0x0(%r13),%edx
  cmp    $0x2f,%dl
  je     L226
  test   %dl,%dl
  je     L72
  mov    %r13,%rbx
L397:
  mov    %rbx,%r12
  add    $0x1,%rbx
  movzbl (%rbx),%eax
  cmp    $0x2f,%al
  je     L115
  test   %al,%al
  jne    L397
L115:
  cmp    $0x2e,%dl
  je     L299
L48:
  mov    %r14,%rax
  sub    %r15,%rax
  lea    0x1(%rbx,%rax,1),%rax
  sub    %r13,%rax
  mov    D16(%rip),%rdx
  movslq (%rdx),%rdx
  cmp    %rdx,%rax
  jge    L70
  movb   $0x2f,(%r14)
  mov    %rbx,%rdx
  sub    %r13,%rdx
  lea    0x1(%r14),%rdi
  mov    %r13,%rsi
  call   <memcpy@plt>
  add    $0x2,%r12
  sub    %r13,%r12
  add    %r14,%r12
  movb   $0x0,(%r12)
  mov    -0x48(%rbp),%rsi
  mov    %r15,%rdi
  call   <lstat@plt>
  cmp    $0xffffffff,%eax
  je     L382
  mov    -0x3c(%rbp),%edi
  call   <S_ISLNK@plt>
  test   %rax,%rax
  je     L66
  mov    -0x54(%rbp),%ecx
  lea    0x1(%rcx),%eax
  mov    %eax,-0x54(%rbp)
  mov    D130(%rip),%rax
  cmp    %ecx,(%rax)
  jle    L323
  movslq -0x58(%rbp),%rax
  imul   -0x50(%rbp),%rax
  mov    %rax,-0x68(%rbp)
  mov    -0x60(%rbp),%r13
  add    %rax,%r13
  mov    -0x6c(%rbp),%eax
  lea    -0x1(%rax),%edx
  mov    %r13,%rsi
  mov    %r15,%rdi
  call   <readlink@plt>
  mov    %rax,%r12
  test   %rax,%rax
  je     L312
  mov    %rbx,%rdi
  call   <strlen@plt>
  lea    0x1(%r12,%rax,1),%rdx
  cmp    %rdx,-0x50(%rbp)
  jb     L256
  lea    0x1(%rax),%rdx
  mov    -0x68(%rbp),%rdi
  add    %r12,%rdi
  add    -0x60(%rbp),%rdi
  mov    %rbx,%rsi
  call   <memcpy@plt>
  xorl   $0x1,-0x58(%rbp)
  cmpb   $0x2f,0x0(%r13)
  cmove  %r15,%r14
  jmp    L375
L389:
  mov    %rbx,%r13
  jmp    L375
L72:
  cmp    %r14,%r15
  je     L384
L88:
  movb   $0x0,(%r14)
  mov    %r15,%rax
  jmp    L282
L384:
  movb   $0x2f,(%r14)
  lea    0x1(%r14),%r14
  jmp    L88
L299:
  mov    %rbx,%rax
  sub    %r13,%rax
  cmp    $0x1,%rax
  je     L389
  cmpb   $0x2e,0x1(%r13)
  jne    L48
  cmp    $0x2,%rax
  jne    L48
  mov    %rbx,%r13
  cmp    %r14,%r15
  je     L375
L405:
  sub    $0x1,%r14
  cmpb   $0x2f,(%r14)
  jne    L405
  mov    %rbx,%r13
  jmp    L375
L70:
  mov    D132(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  cmp    %r14,%r15
  je     L395
L186:
  movb   $0x0,(%r14)
  jmp    L382
L395:
  movb   $0x2f,(%r14)
  lea    0x1(%r14),%r14
  jmp    L186
L323:
  mov    D107(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  jmp    L382
L312:
  mov    D23(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  jmp    L382
L256:
  mov    D132(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  jmp    L382
L66:
  mov    %r12,%r14
  mov    %rbx,%r13
  cmpb   $0x2f,(%rbx)
  jne    L375
  mov    -0x3c(%rbp),%edi
  call   <S_ISDIR@plt>
  test   %eax,%eax
  je     L446
  mov    %r12,%r14
  mov    %rbx,%r13
  jmp    L375
L446:
  mov    D139(%rip),%rax
  mov    (%rax),%edx
  mov    D106(%rip),%rax
  mov    %edx,(%rax)
  jmp    L382
L116:
  call   <__stack_chk_fail@plt>
```

assistant: ```c
char *realpath(const char *path, char *resolved) {
  struct stat sb;
  int idx = 0, nlnk = 0;
  const char *q;
  char *p, wbuf[2][MAXPATHLEN], *fres;
  size_t len;
  ssize_t n;
  if (path == NULL) {
    errno = EINVAL;
    return NULL;
  }
  if (resolved == NULL) {
    fres = resolved = malloc(MAXPATHLEN);
    if (resolved == NULL)
      return NULL;
  } else
    fres = NULL;
  p = resolved;
  if (*path == '\0') {
    *p = '\0';
    errno = ENOENT;
    goto out;
  }
  if (*path != '/') {
    if (resolved && getcwd(resolved, MAXPATHLEN) == NULL) {
      p[0] = '.';
      p[1] = '\0';
      goto out;
    }
    len = strlen(resolved);
    if (len > 1)
      p += len;
  }
loop:
  while (*path == '/')
    path++;
  if (*path == '\0') {
    if (p == resolved)
      *p++ = '/';
    *p = '\0';
    return resolved;
  }
  q = path;
  do
    q++;
  while (*q != '/' && *q != '\0');
  if (path[0] == '.') {
    if (q - path == 1) {
      path = q;
      goto loop;
    }
    if (path[1] == '.' && q - path == 2) {
      if (p != resolved)
        while (*--p != '/')
          continue;
      path = q;
      goto loop;
    }
  }
  if (p - resolved + 1 + q - path + 1 > MAXPATHLEN) {
    errno = ENAMETOOLONG;
    if (p == resolved)
      *p++ = '/';
    *p = '\0';
    goto out;
  }
  p[0] = '/';
  memcpy(&p[1], path, q - path);
  p[1 + q - path] = '\0';
  if (lstat(resolved, &sb) == -1)
    goto out;
  if (S_ISLNK(sb.st_mode)) {
    if (nlnk++ >= MAXSYMLINKS) {
      errno = ELOOP;
      goto out;
    }
    n = readlink(resolved, wbuf[idx], sizeof(wbuf[0]) - 1);
    if (n < 0)
      goto out;
    if (n == 0) {
      errno = ENOENT;
      goto out;
    }
    if (n + (len = strlen(q)) + 1 > sizeof(wbuf[0])) {
      errno = ENAMETOOLONG;
      goto out;
    }
    memcpy(&wbuf[idx][n], q, len + 1);
    path = wbuf[idx];
    idx ^= 1;
    if (*path == '/')
      p = resolved;
    goto loop;
  }
  if (*q == '/' && !S_ISDIR(sb.st_mode)) {
    errno = ENOTDIR;
    goto out;
  }
  p += 1 + q - path;
  path = q;
  goto loop;
out:
  free(fres);
  return NULL;
}
```