xref: /llvm-project/libcxx/test/std/utilities/format/format.functions/format.verify.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
10 
11 // TODO FMT This test should not require std::to_chars(floating-point)
12 // XFAIL: availability-fp_to_chars-missing
13 
14 // Basic test to validate ill-formed code is properly detected.
15 
16 // <format>
17 
18 // template<class... Args>
19 //   string format(format-string<Args...> fmt, const Args&... args);
20 // template<class... Args>
21 //   wstring format(wformat-string<Args...> fmt, const Args&... args);
22 
23 #include <format>
24 
25 #include "test_macros.h"
26 
27 // clang-format off
28 
29 void f() {
30   TEST_IGNORE_NODISCARD std::format("{"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
31   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
32 
33   TEST_IGNORE_NODISCARD std::format("}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
34   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
35 
36   TEST_IGNORE_NODISCARD std::format("{}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
37   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
38 
39   TEST_IGNORE_NODISCARD std::format("{0}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
40   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
41 
42   TEST_IGNORE_NODISCARD std::format("{:-}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
43   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
44 
45   TEST_IGNORE_NODISCARD std::format("{:#}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
46   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
47 
48   TEST_IGNORE_NODISCARD std::format("{:L}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
49   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
50 
51   TEST_IGNORE_NODISCARD std::format("{0:{0}}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
52   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
53 
54   TEST_IGNORE_NODISCARD std::format("{:.42d}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
55   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
56 
57   TEST_IGNORE_NODISCARD std::format("{:d}", "Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
58   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
59 
60 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
61   TEST_IGNORE_NODISCARD std::format(L"{"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
62   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
63 
64   TEST_IGNORE_NODISCARD std::format(L"}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
65   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
66 
67   TEST_IGNORE_NODISCARD std::format(L"{}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
68   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
69 
70   TEST_IGNORE_NODISCARD std::format(L"{0}"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
71   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
72 
73   TEST_IGNORE_NODISCARD std::format(L"{:-}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
74   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
75 
76   TEST_IGNORE_NODISCARD std::format(L"{:#}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
77   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
78 
79   TEST_IGNORE_NODISCARD std::format(L"{:L}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
80   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
81 
82   TEST_IGNORE_NODISCARD std::format(L"{0:{0}}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
83   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
84 
85   TEST_IGNORE_NODISCARD std::format(L"{:.42d}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
86   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
87 
88   TEST_IGNORE_NODISCARD std::format(L"{:d}", L"Forty-two"); // expected-error-re{{call to consteval function '{{.*}}' is not a constant expression}}
89   // expected-note@*:* {{non-constexpr function '__throw_format_error' cannot be used in a constant expression}}
90 #endif
91 }
92 
93 struct tiny {
94   int bit : 1;
95 };
96 
97 void P2418()
98 {
99   auto t = tiny{};
100   TEST_IGNORE_NODISCARD std::format("{}", t.bit); // expected-error{{non-const reference cannot bind to bit-field 'bit'}}
101 
102 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
103   TEST_IGNORE_NODISCARD std::format(L"{}", t.bit); // expected-error{{non-const reference cannot bind to bit-field 'bit'}}
104 #endif
105 }
106