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/__support/macros/config.h" 14 #include "src/stdio/scanf_core/reader.h" 15 #include "src/stdio/scanf_core/scanf_main.h" 16 17 #include "hdr/stdio_macros.h" 18 #include "hdr/types/FILE.h" 19 #include <stdarg.h> 20 21 namespace LIBC_NAMESPACE_DECL { 22 23 LLVM_LIBC_FUNCTION(int, sscanf, 24 (const char *__restrict buffer, 25 const char *__restrict format, ...)) { 26 va_list vlist; 27 va_start(vlist, format); 28 internal::ArgList args(vlist); // This holder class allows for easier copying 29 // and pointer semantics, as well as handling 30 // destruction automatically. 31 va_end(vlist); 32 scanf_core::ReadBuffer rb{buffer, cpp::numeric_limits<size_t>::max()}; 33 scanf_core::Reader reader(&rb); 34 int ret_val = scanf_core::scanf_main(&reader, 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_DECL 41