xref: /aosp_15_r20/external/llvm-libc/src/stdio/vsscanf.cpp (revision 71db0c75aadcf003ffe3238005f61d7618a3fead)
1 //===-- Implementation of vsscanf -------------------------------*- 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/vsscanf.h"
10 
11 #include "hdr/stdio_macros.h"
12 #include "src/__support/CPP/limits.h"
13 #include "src/__support/arg_list.h"
14 #include "src/stdio/scanf_core/reader.h"
15 #include "src/stdio/scanf_core/scanf_main.h"
16 
17 #include <stdarg.h>
18 
19 namespace LIBC_NAMESPACE_DECL {
20 
21 LLVM_LIBC_FUNCTION(int, vsscanf,
22                    (const char *buffer, const char *format, va_list vlist)) {
23   internal::ArgList args(vlist);
24   scanf_core::ReadBuffer rb{const_cast<char *>(buffer),
25                             cpp::numeric_limits<size_t>::max()};
26   scanf_core::Reader reader(&rb);
27   int ret_val = scanf_core::scanf_main(&reader, format, args);
28   // This is done to avoid including stdio.h in the internals. On most systems
29   // EOF is -1, so this will be transformed into just "return ret_val".
30   return (ret_val == -1) ? EOF : ret_val;
31 }
32 
33 } // namespace LIBC_NAMESPACE_DECL
34