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/__support/macros/config.h" |
13 | #include "src/stdio/printf_core/printf_main.h" |
14 | #include "src/stdio/printf_core/writer.h" |
15 | |
16 | #include <stdarg.h> |
17 | #include <stddef.h> |
18 | |
19 | namespace LIBC_NAMESPACE_DECL { |
20 | |
21 | LLVM_LIBC_FUNCTION(int, snprintf, |
22 | (char *__restrict buffer, size_t buffsz, |
23 | const char *__restrict format, ...)) { |
24 | va_list vlist; |
25 | va_start(vlist, format); |
26 | internal::ArgList args(vlist); // This holder class allows for easier copying |
27 | // and pointer semantics, as well as handling |
28 | // destruction automatically. |
29 | va_end(vlist); |
30 | printf_core::WriteBuffer<printf_core::Mode< |
31 | printf_core::WriteMode::FILL_BUFF_AND_DROP_OVERFLOW>::value> |
32 | wb(buffer, (buffsz > 0 ? buffsz - 1 : 0)); |
33 | printf_core::Writer writer(wb); |
34 | |
35 | int ret_val = printf_core::printf_main(&writer, format, args); |
36 | if (buffsz > 0) // if the buffsz is 0 the buffer may be a null pointer. |
37 | wb.buff[wb.buff_cur] = '\0'; |
38 | return ret_val; |
39 | } |
40 | |
41 | } // namespace LIBC_NAMESPACE_DECL |
42 | |