1 //===-- Implementation of sscanf --------------------------------*- 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/sscanf.h" 10 11 #include "src/__support/CPP/limits.h" 12 #include "src/__support/arg_list.h" 13 #include "src/stdio/scanf_core/reader.h" 14 #include "src/stdio/scanf_core/scanf_main.h" 15 16 #include <stdarg.h> 17 #include <stdio.h> 18 19 namespace LIBC_NAMESPACE { 20 21 LLVM_LIBC_FUNCTION(int, sscanf, 22 (const char *__restrict buffer, 23 const char *__restrict format, ...)) { 24 va_list vlist; 25 va_start(vlist, format); 26 internal::ArgList args(vlist); // This holder class allows for easier copying 27 // and pointer semantics, as well as handling 28 // destruction automatically. 29 va_end(vlist); 30 scanf_core::ReadBuffer rb{const_cast<char *>(buffer), 31 cpp::numeric_limits<size_t>::max()}; 32 scanf_core::Reader reader(&rb); 33 int ret_val = scanf_core::scanf_main(&reader, format, args); 34 // This is done to avoid including stdio.h in the internals. On most systems 35 // EOF is -1, so this will be transformed into just "return ret_val". 36 return (ret_val == -1) ? EOF : ret_val; 37 } 38 39 } // namespace LIBC_NAMESPACE 40