xref: /llvm-project/libcxx/test/std/input.output/iostream.format/print.fun/print.file.pass.cpp (revision 6a54dfbfe534276d644d7f9c027f0deeb748dd53)
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 // UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
10 // UNSUPPORTED: no-filesystem
11 // UNSUPPORTED: GCC-ALWAYS_INLINE-FIXME
12 
13 // XFAIL: availability-fp_to_chars-missing
14 
15 // The error exception has no system error string.
16 // XFAIL: LIBCXX-ANDROID-FIXME
17 
18 // <print>
19 
20 // template<class... Args>
21 //   void print(FILE* stream, format_string<Args...> fmt, Args&&... args);
22 
23 // In the library when the stdout is redirected to a file it is no
24 // longer considered a terminal and the special terminal handling is no
25 // longer executed. There are tests in
26 //   libcxx/test/libcxx/input.output/iostream.format/print.fun/
27 // to validate that behaviour
28 
29 #include <algorithm>
30 #include <array>
31 #include <cassert>
32 #include <cstddef>
33 #include <cstdio>
34 #include <fstream>
35 #include <iterator>
36 #include <print>
37 #include <string_view>
38 
39 #include "assert_macros.h"
40 #include "concat_macros.h"
41 #include "filesystem_test_helper.h"
42 #include "print_tests.h"
43 #include "test_format_string.h"
44 #include "test_macros.h"
45 
46 scoped_test_env env;
47 std::string filename = env.create_file("output.txt");
48 
49 auto test_file = []<class... Args>(std::string_view expected, test_format_string<char, Args...> fmt, Args&&... args) {
50   FILE* file = fopen(filename.c_str(), "wb");
51   assert(file);
52 
53   std::print(file, fmt, std::forward<Args>(args)...);
54   std::fclose(file);
55 
56   std::ifstream stream{filename.c_str(), std::ios_base::in | std::ios_base::binary};
57   std::string out(std::istreambuf_iterator<char>{stream}, {});
58   TEST_REQUIRE(out == expected,
59                TEST_WRITE_CONCATENATED(
60                    "\nFormat string   ", fmt.get(), "\nExpected output ", expected, "\nActual output   ", out, '\n'));
61 };
62 
63 auto test_exception = []<class... Args>(std::string_view, std::string_view, Args&&...) {
64   // After P2216 most exceptions thrown by std::format become ill-formed.
65   // Therefore this tests does nothing.
66   // A basic ill-formed test is done in format.verify.cpp
67   // The exceptions are tested by other functions that don't use the basic-format-string as fmt argument.
68 };
69 
70 // Glibc fails writing to a wide stream.
71 #if defined(TEST_HAS_GLIBC) && !defined(TEST_HAS_NO_WIDE_CHARACTERS)
72 static void test_wide_stream() {
73   FILE* file = fopen(filename.c_str(), "wb");
74   assert(file);
75 
76   int mode = std::fwide(file, 1);
77   assert(mode > 0);
78 
79   TEST_VALIDATE_EXCEPTION(
80       std::system_error,
81       [&]([[maybe_unused]] const std::system_error& e) {
82         [[maybe_unused]] std::string_view what{"failed to write formatted output"};
83         TEST_LIBCPP_REQUIRE(
84             e.what() == what,
85             TEST_WRITE_CONCATENATED("\nExpected exception ", what, "\nActual exception   ", e.what(), '\n'));
86       },
87       std::print(file, "hello"));
88 }
89 #endif // defined(TEST_HAS_GLIBC) && !defined(TEST_HAS_NO_WIDE_CHARACTERS)
90 
91 static void test_read_only() {
92   FILE* file = fopen(filename.c_str(), "r");
93   assert(file);
94 
95   TEST_VALIDATE_EXCEPTION(
96       std::system_error,
97       [&]([[maybe_unused]] const std::system_error& e) {
98         [[maybe_unused]] std::string_view what{
99             "failed to write formatted output: " TEST_IF_AIX("Broken pipe", "Operation not permitted")};
100         TEST_LIBCPP_REQUIRE(
101             e.what() == what,
102             TEST_WRITE_CONCATENATED("\nExpected exception ", what, "\nActual exception   ", e.what(), '\n'));
103       },
104       std::print(file, "hello"));
105 }
106 
107 static void test_new_line() {
108   // Text does newline translation.
109   {
110     FILE* file = fopen(filename.c_str(), "w");
111     assert(file);
112 
113     std::print(file, "\n");
114 #ifndef _WIN32
115     assert(std::ftell(file) == 1);
116 #else
117     assert(std::ftell(file) == 2);
118 #endif
119   }
120   // Binary no newline translation.
121   {
122     FILE* file = fopen(filename.c_str(), "wb");
123     assert(file);
124 
125     std::print(file, "\n");
126     assert(std::ftell(file) == 1);
127   }
128 }
129 
130 int main(int, char**) {
131   print_tests(test_file, test_exception);
132 
133 #if defined(TEST_HAS_GLIBC) && !defined(TEST_HAS_NO_WIDE_CHARACTERS)
134   test_wide_stream();
135 #endif
136   test_read_only();
137   test_new_line();
138 
139   return 0;
140 }
141