libc/src/stdio/vsscanf.cpp

   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