1 //===----------------------------------------------------------------------===// 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 // REQUIRES: locale.en_US.UTF-8 10 11 // <fstream> 12 13 // int_type underflow(); 14 15 // This test is not entirely portable 16 17 #include <fstream> 18 #include <cstddef> 19 #include <cassert> 20 21 #include "platform_support.h" // locale name macros 22 23 template <class CharT> 24 struct test_buf 25 : public std::basic_filebuf<CharT> 26 { 27 typedef std::basic_filebuf<CharT> base; 28 typedef typename base::char_type char_type; 29 typedef typename base::int_type int_type; 30 31 char_type* eback() const {return base::eback();} 32 char_type* gptr() const {return base::gptr();} 33 char_type* egptr() const {return base::egptr();} 34 void gbump(int n) {base::gbump(n);} 35 36 virtual int_type underflow() {return base::underflow();} 37 }; 38 39 int main(int, char**) 40 { 41 { 42 test_buf<char> f; 43 assert(f.open("underflow.dat", std::ios_base::in) != 0); 44 assert(f.is_open()); 45 assert(f.eback() == 0); 46 assert(f.gptr() == 0); 47 assert(f.egptr() == 0); 48 assert(f.underflow() == '1'); 49 assert(f.eback() != 0); 50 assert(f.eback() == f.gptr()); 51 assert(*f.gptr() == '1'); 52 assert(f.egptr() - f.eback() == 9); 53 } 54 { 55 test_buf<char> f; 56 assert(f.open("underflow.dat", std::ios_base::in) != 0); 57 assert(f.pubsetbuf(0, 0)); 58 assert(f.is_open()); 59 assert(f.eback() == 0); 60 assert(f.gptr() == 0); 61 assert(f.egptr() == 0); 62 assert(f.underflow() == '1'); 63 assert(f.eback() != 0); 64 assert(f.eback() == f.gptr()); 65 assert(*f.gptr() == '1'); 66 assert(f.egptr() - f.eback() == 8); 67 f.gbump(8); 68 assert(f.sgetc() == '9'); 69 assert(f.eback()[0] == '5'); 70 assert(f.eback()[1] == '6'); 71 assert(f.eback()[2] == '7'); 72 assert(f.eback()[3] == '8'); 73 assert(f.gptr() - f.eback() == 4); 74 assert(*f.gptr() == '9'); 75 assert(f.egptr() - f.gptr() == 1); 76 } 77 { 78 test_buf<wchar_t> f; 79 assert(f.open("underflow.dat", std::ios_base::in) != 0); 80 assert(f.is_open()); 81 assert(f.eback() == 0); 82 assert(f.gptr() == 0); 83 assert(f.egptr() == 0); 84 assert(f.underflow() == L'1'); 85 assert(f.eback() != 0); 86 assert(f.eback() == f.gptr()); 87 assert(*f.gptr() == L'1'); 88 assert(f.egptr() - f.eback() == 9); 89 } 90 { 91 test_buf<wchar_t> f; 92 assert(f.pubsetbuf(0, 0)); 93 assert(f.open("underflow.dat", std::ios_base::in) != 0); 94 assert(f.is_open()); 95 assert(f.eback() == 0); 96 assert(f.gptr() == 0); 97 assert(f.egptr() == 0); 98 assert(f.underflow() == L'1'); 99 assert(f.eback() != 0); 100 assert(f.eback() == f.gptr()); 101 assert(*f.gptr() == L'1'); 102 assert(f.egptr() - f.eback() == 8); 103 f.gbump(8); 104 assert(f.sgetc() == L'9'); 105 assert(f.eback()[0] == L'5'); 106 assert(f.eback()[1] == L'6'); 107 assert(f.eback()[2] == L'7'); 108 assert(f.eback()[3] == L'8'); 109 assert(f.gptr() - f.eback() == 4); 110 assert(*f.gptr() == L'9'); 111 assert(f.egptr() - f.gptr() == 1); 112 } 113 { 114 typedef std::char_traits<wchar_t> Traits; 115 test_buf<wchar_t> f; 116 f.pubimbue(std::locale(LOCALE_en_US_UTF_8)); 117 assert(f.open("underflow_utf8.dat", std::ios_base::in) != 0); 118 assert(f.is_open()); 119 assert(f.sbumpc() == 0x4E51); 120 assert(f.sbumpc() == 0x4E52); 121 assert(f.sbumpc() == 0x4E53); 122 assert(f.sbumpc() == static_cast<Traits::int_type>(-1)); 123 } 124 125 return 0; 126 } 127