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 // FILE_DEPENDENCIES: underflow.dat, underflow_utf8.dat 11 12 // <fstream> 13 14 // int_type underflow(); 15 16 // This test is not entirely portable 17 18 #include <fstream> 19 #include <cstddef> 20 #include <cassert> 21 22 #include "test_macros.h" 23 #include "platform_support.h" // locale name macros 24 25 template <class CharT> 26 struct test_buf 27 : public std::basic_filebuf<CharT> 28 { 29 typedef std::basic_filebuf<CharT> base; 30 typedef typename base::char_type char_type; 31 typedef typename base::int_type int_type; 32 33 char_type* eback() const {return base::eback();} 34 char_type* gptr() const {return base::gptr();} 35 char_type* egptr() const {return base::egptr();} 36 void gbump(int n) {base::gbump(n);} 37 38 virtual int_type underflow() {return base::underflow();} 39 }; 40 41 int main(int, char**) 42 { 43 { 44 test_buf<char> f; 45 assert(f.open("underflow.dat", std::ios_base::in) != 0); 46 assert(f.is_open()); 47 assert(f.eback() == 0); 48 assert(f.gptr() == 0); 49 assert(f.egptr() == 0); 50 assert(f.underflow() == '1'); 51 assert(f.eback() != 0); 52 assert(f.eback() == f.gptr()); 53 assert(*f.gptr() == '1'); 54 assert(f.egptr() - f.eback() == 9); 55 } 56 { 57 test_buf<char> f; 58 assert(f.open("underflow.dat", std::ios_base::in) != 0); 59 assert(f.pubsetbuf(0, 0)); 60 assert(f.is_open()); 61 assert(f.eback() == 0); 62 assert(f.gptr() == 0); 63 assert(f.egptr() == 0); 64 assert(f.underflow() == '1'); 65 assert(f.eback() != 0); 66 assert(f.eback() == f.gptr()); 67 assert(*f.gptr() == '1'); 68 assert(f.egptr() - f.eback() == 8); 69 f.gbump(8); 70 assert(f.sgetc() == '9'); 71 assert(f.eback()[0] == '5'); 72 assert(f.eback()[1] == '6'); 73 assert(f.eback()[2] == '7'); 74 assert(f.eback()[3] == '8'); 75 assert(f.gptr() - f.eback() == 4); 76 assert(*f.gptr() == '9'); 77 assert(f.egptr() - f.gptr() == 1); 78 } 79 #ifndef TEST_HAS_NO_WIDE_CHARACTERS 80 { 81 test_buf<wchar_t> f; 82 assert(f.open("underflow.dat", std::ios_base::in) != 0); 83 assert(f.is_open()); 84 assert(f.eback() == 0); 85 assert(f.gptr() == 0); 86 assert(f.egptr() == 0); 87 assert(f.underflow() == L'1'); 88 assert(f.eback() != 0); 89 assert(f.eback() == f.gptr()); 90 assert(*f.gptr() == L'1'); 91 assert(f.egptr() - f.eback() == 9); 92 } 93 { 94 test_buf<wchar_t> f; 95 assert(f.pubsetbuf(0, 0)); 96 assert(f.open("underflow.dat", std::ios_base::in) != 0); 97 assert(f.is_open()); 98 assert(f.eback() == 0); 99 assert(f.gptr() == 0); 100 assert(f.egptr() == 0); 101 assert(f.underflow() == L'1'); 102 assert(f.eback() != 0); 103 assert(f.eback() == f.gptr()); 104 assert(*f.gptr() == L'1'); 105 assert(f.egptr() - f.eback() == 8); 106 f.gbump(8); 107 assert(f.sgetc() == L'9'); 108 assert(f.eback()[0] == L'5'); 109 assert(f.eback()[1] == L'6'); 110 assert(f.eback()[2] == L'7'); 111 assert(f.eback()[3] == L'8'); 112 assert(f.gptr() - f.eback() == 4); 113 assert(*f.gptr() == L'9'); 114 assert(f.egptr() - f.gptr() == 1); 115 } 116 { 117 typedef std::char_traits<wchar_t> Traits; 118 test_buf<wchar_t> f; 119 f.pubimbue(std::locale(LOCALE_en_US_UTF_8)); 120 assert(f.open("underflow_utf8.dat", std::ios_base::in) != 0); 121 assert(f.is_open()); 122 assert(f.sbumpc() == 0x4E51); 123 assert(f.sbumpc() == 0x4E52); 124 assert(f.sbumpc() == 0x4E53); 125 assert(f.sbumpc() == static_cast<Traits::int_type>(-1)); 126 } 127 #endif // TEST_HAS_NO_WIDE_CHARACTERS 128 129 return 0; 130 } 131