1 //===-- Implementation of printf for baremetal ------------------*- 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/printf.h" 10 #include "src/__support/OSUtil/io.h" 11 #include "src/__support/arg_list.h" 12 #include "src/__support/macros/config.h" 13 #include "src/stdio/printf_core/core_structs.h" 14 #include "src/stdio/printf_core/printf_main.h" 15 #include "src/stdio/printf_core/writer.h" 16 17 #include <stdarg.h> 18 #include <stddef.h> 19 20 namespace LIBC_NAMESPACE_DECL { 21 22 namespace { 23 24 LIBC_INLINE int raw_write_hook(cpp::string_view new_str, void *) { 25 write_to_stderr(new_str); 26 return printf_core::WRITE_OK; 27 } 28 29 } // namespace 30 31 LLVM_LIBC_FUNCTION(int, printf, (const char *__restrict format, ...)) { 32 va_list vlist; 33 va_start(vlist, format); 34 internal::ArgList args(vlist); // This holder class allows for easier copying 35 // and pointer semantics, as well as handling 36 // destruction automatically. 37 va_end(vlist); 38 constexpr size_t BUFF_SIZE = 1024; 39 char buffer[BUFF_SIZE]; 40 41 printf_core::WriteBuffer wb(buffer, BUFF_SIZE, &raw_write_hook, nullptr); 42 printf_core::Writer writer(&wb); 43 44 int retval = printf_core::printf_main(&writer, format, args); 45 46 int flushval = wb.overflow_write(""); 47 if (flushval != printf_core::WRITE_OK) 48 retval = flushval; 49 50 return retval; 51 } 52 53 } // namespace LIBC_NAMESPACE_DECL 54