user: What would the C source look like for the assembly code provided here:

```asm
<DateFmt>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  mov    %rdi,%r12
  push   %rbp
  push   %rbx
  sub    $0x38,%rsp
  mov    %fs:0x28,%rax
  mov    %rax,0x28(%rsp)
  xor    %eax,%eax
  test   %rsi,%rsi
  jle    L134
  mov    %rsi,%rbp
  mov    %rdx,%r14
  lea    0xc(%rsp),%rcx
  mov    %r12,%rbx
  lea    0x8(%rsp),%rdx
  lea    0x4(%rsp),%rsi
  mov    %rbp,%rdi
  call   <Date_ymd@plt>
  movzbl (%r14),%eax
  test   %al,%al
  je     L10
  lea    D35(%rip),%r15
  lea    D42(%rip),%r13
  jmp    L16
  cs nopw 0x0(%rax,%rax,1)
L99:
  mov    %al,(%rbx)
  add    $0x1,%rbx
  movzbl 0x1(%r14),%eax
  mov    %rdx,%r14
L269:
  test   %al,%al
  je     L10
L16:
  lea    0x1(%r14),%rdx
  cmp    $0x25,%al
  jne    L99
  movzbl 0x1(%r14),%edx
  test   %dl,%dl
  je     L10
  lea    -0x44(%rdx),%eax
  cmp    $0x35,%al
  ja     L120
  movzbl %al,%eax
  movslq (%r15,%rax,4),%rax
  add    %r15,%rax
  notrack jmp *%rax
  nopw   0x0(%rax,%rax,1)
L10:
  movb   $0x0,(%rbx)
L207:
  mov    0x28(%rsp),%rax
  sub    %fs:0x28,%rax
  jne    L239
  add    $0x38,%rsp
  mov    %r12,%rax
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
  nopl   0x0(%rax)
L134:
  movb   $0x0,(%rdi)
  jmp    L207
  nopl   (%rax)
L120:
  mov    %dl,(%rbx)
  add    $0x2,%r14
  movzbl (%r14),%eax
  add    $0x1,%rbx
  jmp    L269
  nopl   0x0(%rax,%rax,1)
  mov    0xc(%rsp),%edi
  call   <Num_sufx@plt>
L208:
  mov    %eax,%esi
  mov    %rbx,%rdi
  call   <strcpy@plt>
L127:
  mov    %rbx,%rdi
  call   <strlen@plt>
  cltq
  add    %rax,%rbx
L61:
  movzbl 0x2(%r14),%eax
  add    $0x2,%r14
  jmp    L269
  xchg   %ax,%ax
  lea    0x10(%rsp),%rdi
  call   <Time2@plt>
  jmp    L208
  nopl   0x0(%rax)
  xor    %esi,%esi
  mov    %rbp,%rdi
  call   <Dyofwk@plt>
  jmp    L208
  mov    0xc(%rsp),%edx
  lea    D25(%rip),%rsi
  mov    %rbx,%rdi
  call   <sprintf@plt>
  jmp    L127
  mov    0x8(%rsp),%edi
  xor    %esi,%esi
  add    $0x2,%r14
  call   <Mmofyr@plt>
  mov    %rbx,%rdi
  add    $0x3,%rbx
  mov    %eax,%esi
  call   <strcpy@plt>
  movzbl (%r14),%eax
  jmp    L269
  mov    0x8(%rsp),%edx
  lea    D25(%rip),%rsi
  mov    %rbx,%rdi
  call   <sprintf@plt>
  jmp    L127
  movslq 0x4(%rsp),%rax
  mov    %rbx,%rdi
  mov    %rax,%rdx
  imul   $0x51eb851f,%rax,%rax
  mov    %edx,%esi
  sar    $0x1f,%esi
  sar    $0x25,%rax
  sub    %esi,%eax
  mov    %r13,%rsi
  imul   $0x64,%eax,%eax
  sub    %eax,%edx
  call   <sprintf@plt>
  movzbl (%rbx),%eax
  test   %al,%al
  je     L61
  nopl   0x0(%rax)
L37:
  cmp    $0x20,%al
  jne    L210
  movb   $0x30,(%rbx)
L210:
  movzbl 0x1(%rbx),%eax
  add    $0x1,%rbx
  test   %al,%al
  jne    L37
  jmp    L61
  mov    0xc(%rsp),%edx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <sprintf@plt>
  movzbl (%rbx),%eax
  test   %al,%al
  je     L61
  nopw   0x0(%rax,%rax,1)
L114:
  cmp    $0x20,%al
  jne    L93
  movb   $0x30,(%rbx)
L93:
  movzbl 0x1(%rbx),%eax
  add    $0x1,%rbx
  test   %al,%al
  jne    L114
  jmp    L61
  mov    0x8(%rsp),%edi
  xor    %esi,%esi
  call   <Mmofyr@plt>
  jmp    L208
  mov    0x8(%rsp),%edx
  mov    %r13,%rsi
  mov    %rbx,%rdi
  call   <sprintf@plt>
  jmp    L127
  mov    0x4(%rsp),%edx
  lea    D4(%rip),%rsi
  mov    %rbx,%rdi
  call   <sprintf@plt>
  jmp    L127
L239:
  call   <__stack_chk_fail@plt>
```

tool_calls: name: unpack_data
arguments: data_tag: D42
datatype: string
name: unpack_data
arguments: data_tag: D25
datatype: string
name: unpack_data
arguments: data_tag: D4
datatype: string

tool: D42: %02d

tool: D25: %d

tool: D4: %4d

assistant: ```c
char *DateFmt(char *buf, long dt, char *msk) {
  int y, m, d;
  char tmp[20], *bp = buf;
  if (dt <= 0L) {
    *buf = '\0';
    return (buf);
  }
  Date_ymd(dt, &y, &m, &d);
  while (*msk)
    if (*msk != '%')
      *bp++ = *msk++;
    else
      switch (*++msk) {
      case '\0':
        break;
      case '%':
      default:
        *bp++ = *msk++;
        break;
      case 'W':
      case 'w':
        strcpy(bp, Dyofwk(dt, NULL));
        bp += strlen(bp);
        msk++;
        break;
      case 'M':
        strcpy(bp, Mmofyr(m, NULL));
        bp += strlen(bp);
        msk++;
        break;
      case 'm':
        strcpy(bp, Mmofyr(m, NULL));
        bp += 3;
        msk++;
        break;
      case 'd':
        sprintf(bp, "%d", d);
        bp += strlen(bp);
        msk++;
        break;
      case 'D':
        sprintf(bp, "%02d", d);
        for (; *bp; ++bp)
          if (*bp == ' ')
            *bp = '0';
        msk++;
        break;
      case 'y':
        sprintf(bp, "%02d", y % 100);
        for (; *bp; ++bp)
          if (*bp == ' ')
            *bp = '0';
        msk++;
        break;
      case 'Y':
        sprintf(bp, "%4d", y);
        bp += strlen(bp);
        msk++;
        break;
      case 'S':
      case 's':
        strcpy(bp, Num_sufx(d));
        bp += strlen(bp);
        msk++;
        break;
      case 'n':
        sprintf(bp, "%d", m);
        bp += strlen(bp);
        msk++;
        break;
      case 'N':
        sprintf(bp, "%02d", m);
        bp += strlen(bp);
        msk++;
        break;
      case 'T':
      case 't':
        strcpy(bp, Time2(tmp));
        bp += strlen(bp);
        msk++;
        break;
      }
  *bp = '\0';
  return (buf);
}
```