1//===-- Implementation of snprintf ------------------------------*- C++ -*-===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "src/stdio/snprintf.h"
10
11#include "src/__support/arg_list.h"
12#include "src/stdio/printf_core/printf_main.h"
13#include "src/stdio/printf_core/writer.h"
14
15#include <stdarg.h>
16#include <stddef.h>
17
18namespace LIBC_NAMESPACE {
19
20LLVM_LIBC_FUNCTION(int, snprintf,
21 (char *__restrict buffer, size_t buffsz,
22 const char *__restrict format, ...)) {
23 va_list vlist;
24 va_start(vlist, format);
25 internal::ArgList args(vlist); // This holder class allows for easier copying
26 // and pointer semantics, as well as handling
27 // destruction automatically.
28 va_end(vlist);
29 printf_core::WriteBuffer wb(buffer, (buffsz > 0 ? buffsz - 1 : 0));
30 printf_core::Writer writer(&wb);
31
32 int ret_val = printf_core::printf_main(writer: &writer, str: format, args);
33 if (buffsz > 0) // if the buffsz is 0 the buffer may be a null pointer.
34 wb.buff[wb.buff_cur] = '\0';
35 return ret_val;
36}
37
38} // namespace LIBC_NAMESPACE
39

source code of libc/src/stdio/snprintf.cpp