libc/src/stdio/scanf.cpp

   1 //===-- Implementation of scanf ---------------------------------*- 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/scanf.h"
  10
  11 #include "src/__support/File/file.h"
  12 #include "src/__support/arg_list.h"
  13 #include "src/stdio/scanf_core/vfscanf_internal.h"
  14
  15 #include <stdarg.h>
  16 #include <stdio.h>
  17
  18 namespace __llvm_libc {
  19
  20 LLVM_LIBC_FUNCTION(int, scanf, (const char *__restrict format, ...)) {
  21   va_list vlist;
  22   va_start(vlist, format);
  23   internal::ArgList args(vlist); // This holder class allows for easier copying
  24                                  // and pointer semantics, as well as handling
  25                                  // destruction automatically.
  26   va_end(vlist);
  27   int ret_val = scanf_core::vfscanf_internal(
  28       reinterpret_cast<::FILE *>(__llvm_libc::stdin), format, args);
  29   // This is done to avoid including stdio.h in the internals. On most systems
  30   // EOF is -1, so this will be transformed into just "return ret_val".
  31   return (ret_val == -1) ? EOF : ret_val;
  32 }
  33
  34 } // namespace __llvm_libc