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/__support/macros/config.h" 14 #include "src/stdio/scanf_core/vfscanf_internal.h" 15 16 #include "hdr/types/FILE.h" 17 #include <stdarg.h> 18 19 #ifndef LIBC_COPT_STDIO_USE_SYSTEM_FILE 20 #define SCANF_STDIN LIBC_NAMESPACE::stdin 21 #else // LIBC_COPT_STDIO_USE_SYSTEM_FILE 22 #define SCANF_STDIN ::stdin 23 #endif // LIBC_COPT_STDIO_USE_SYSTEM_FILE 24 25 namespace LIBC_NAMESPACE_DECL { 26 27 LLVM_LIBC_FUNCTION(int, scanf, (const char *__restrict format, ...)) { 28 va_list vlist; 29 va_start(vlist, format); 30 internal::ArgList args(vlist); // This holder class allows for easier copying 31 // and pointer semantics, as well as handling 32 // destruction automatically. 33 va_end(vlist); 34 int ret_val = scanf_core::vfscanf_internal( 35 reinterpret_cast<::FILE *>(SCANF_STDIN), format, args); 36 // This is done to avoid including stdio.h in the internals. On most systems 37 // EOF is -1, so this will be transformed into just "return ret_val". 38 return (ret_val == -1) ? EOF : ret_val; 39 } 40 41 } // namespace LIBC_NAMESPACE_DECL 42