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 #ifndef LIBC_COPT_STDIO_USE_SYSTEM_FILE 19 #define SCANF_STDIN LIBC_NAMESPACE::stdin 20 #else // LIBC_COPT_STDIO_USE_SYSTEM_FILE 21 #define SCANF_STDIN ::stdin 22 #endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE 23 24 namespace LIBC_NAMESPACE { 25 26 LLVM_LIBC_FUNCTION(int, scanf, (const char *__restrict format, ...)) { 27 va_list vlist; 28 va_start(vlist, format); 29 internal::ArgList args(vlist); // This holder class allows for easier copying 30 // and pointer semantics, as well as handling 31 // destruction automatically. 32 va_end(vlist); 33 int ret_val = scanf_core::vfscanf_internal( 34 reinterpret_cast<::FILE *>(SCANF_STDIN), format, args); 35 // This is done to avoid including stdio.h in the internals. On most systems 36 // EOF is -1, so this will be transformed into just "return ret_val". 37 return (ret_val == -1) ? EOF : ret_val; 38 } 39 40 } // namespace LIBC_NAMESPACE 41