check.h (8494B)
1 // Copyright 2022 The Abseil Authors. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // ----------------------------------------------------------------------------- 16 // File: log/check.h 17 // ----------------------------------------------------------------------------- 18 // 19 // This header declares a family of `CHECK` macros. 20 // 21 // `CHECK` macros terminate the program with a fatal error if the specified 22 // condition is not true. 23 // 24 // Except for those whose names begin with `DCHECK`, these macros are not 25 // controlled by `NDEBUG` (cf. `assert`), so the check will be executed 26 // regardless of compilation mode. `CHECK` and friends are thus useful for 27 // confirming invariants in situations where continuing to run would be worse 28 // than terminating, e.g., due to risk of data corruption or security 29 // compromise. It is also more robust and portable to deliberately terminate 30 // at a particular place with a useful message and backtrace than to assume some 31 // ultimately unspecified and unreliable crashing behavior (such as a 32 // "segmentation fault"). 33 34 #ifndef ABSL_LOG_CHECK_H_ 35 #define ABSL_LOG_CHECK_H_ 36 37 #include "absl/log/internal/check_impl.h" 38 #include "absl/log/internal/check_op.h" // IWYU pragma: export 39 #include "absl/log/internal/conditions.h" // IWYU pragma: export 40 #include "absl/log/internal/log_message.h" // IWYU pragma: export 41 #include "absl/log/internal/strip.h" // IWYU pragma: export 42 43 // CHECK() 44 // 45 // `CHECK` terminates the program with a fatal error if `condition` is not true. 46 // 47 // The message may include additional information such as stack traces, when 48 // available. 49 // 50 // Example: 51 // 52 // CHECK(!cheese.empty()) << "Out of Cheese"; 53 // 54 // Might produce a message like: 55 // 56 // Check failed: !cheese.empty() Out of Cheese 57 #define CHECK(condition) ABSL_LOG_INTERNAL_CHECK_IMPL((condition), #condition) 58 59 // QCHECK() 60 // 61 // `QCHECK` behaves like `CHECK` but does not print a full stack trace and does 62 // not run registered error handlers (as `QFATAL`). It is useful when the 63 // problem is definitely unrelated to program flow, e.g. when validating user 64 // input. 65 #define QCHECK(condition) ABSL_LOG_INTERNAL_QCHECK_IMPL((condition), #condition) 66 67 // PCHECK() 68 // 69 // `PCHECK` behaves like `CHECK` but appends a description of the current state 70 // of `errno` to the failure message. 71 // 72 // Example: 73 // 74 // int fd = open("/var/empty/missing", O_RDONLY); 75 // PCHECK(fd != -1) << "posix is difficult"; 76 // 77 // Might produce a message like: 78 // 79 // Check failed: fd != -1 posix is difficult: No such file or directory [2] 80 #define PCHECK(condition) ABSL_LOG_INTERNAL_PCHECK_IMPL((condition), #condition) 81 82 // DCHECK() 83 // 84 // `DCHECK` behaves like `CHECK` in debug mode and does nothing otherwise (as 85 // `DLOG`). Unlike with `CHECK` (but as with `assert`), it is not safe to rely 86 // on evaluation of `condition`: when `NDEBUG` is enabled, DCHECK does not 87 // evaluate the condition. 88 #define DCHECK(condition) ABSL_LOG_INTERNAL_DCHECK_IMPL((condition), #condition) 89 90 // `CHECK_EQ` and friends are syntactic sugar for `CHECK(x == y)` that 91 // automatically output the expression being tested and the evaluated values on 92 // either side. 93 // 94 // Example: 95 // 96 // int x = 3, y = 5; 97 // CHECK_EQ(2 * x, y) << "oops!"; 98 // 99 // Might produce a message like: 100 // 101 // Check failed: 2 * x == y (6 vs. 5) oops! 102 // 103 // The values must implement the appropriate comparison operator as well as 104 // `operator<<(std::ostream&, ...)`. Care is taken to ensure that each 105 // argument is evaluated exactly once, and that anything which is legal to pass 106 // as a function argument is legal here. In particular, the arguments may be 107 // temporary expressions which will end up being destroyed at the end of the 108 // statement, 109 // 110 // Example: 111 // 112 // CHECK_EQ(std::string("abc")[1], 'b'); 113 // 114 // WARNING: Passing `NULL` as an argument to `CHECK_EQ` and similar macros does 115 // not compile. Use `nullptr` instead. 116 #define CHECK_EQ(val1, val2) \ 117 ABSL_LOG_INTERNAL_CHECK_EQ_IMPL((val1), #val1, (val2), #val2) 118 #define CHECK_NE(val1, val2) \ 119 ABSL_LOG_INTERNAL_CHECK_NE_IMPL((val1), #val1, (val2), #val2) 120 #define CHECK_LE(val1, val2) \ 121 ABSL_LOG_INTERNAL_CHECK_LE_IMPL((val1), #val1, (val2), #val2) 122 #define CHECK_LT(val1, val2) \ 123 ABSL_LOG_INTERNAL_CHECK_LT_IMPL((val1), #val1, (val2), #val2) 124 #define CHECK_GE(val1, val2) \ 125 ABSL_LOG_INTERNAL_CHECK_GE_IMPL((val1), #val1, (val2), #val2) 126 #define CHECK_GT(val1, val2) \ 127 ABSL_LOG_INTERNAL_CHECK_GT_IMPL((val1), #val1, (val2), #val2) 128 #define QCHECK_EQ(val1, val2) \ 129 ABSL_LOG_INTERNAL_QCHECK_EQ_IMPL((val1), #val1, (val2), #val2) 130 #define QCHECK_NE(val1, val2) \ 131 ABSL_LOG_INTERNAL_QCHECK_NE_IMPL((val1), #val1, (val2), #val2) 132 #define QCHECK_LE(val1, val2) \ 133 ABSL_LOG_INTERNAL_QCHECK_LE_IMPL((val1), #val1, (val2), #val2) 134 #define QCHECK_LT(val1, val2) \ 135 ABSL_LOG_INTERNAL_QCHECK_LT_IMPL((val1), #val1, (val2), #val2) 136 #define QCHECK_GE(val1, val2) \ 137 ABSL_LOG_INTERNAL_QCHECK_GE_IMPL((val1), #val1, (val2), #val2) 138 #define QCHECK_GT(val1, val2) \ 139 ABSL_LOG_INTERNAL_QCHECK_GT_IMPL((val1), #val1, (val2), #val2) 140 #define DCHECK_EQ(val1, val2) \ 141 ABSL_LOG_INTERNAL_DCHECK_EQ_IMPL((val1), #val1, (val2), #val2) 142 #define DCHECK_NE(val1, val2) \ 143 ABSL_LOG_INTERNAL_DCHECK_NE_IMPL((val1), #val1, (val2), #val2) 144 #define DCHECK_LE(val1, val2) \ 145 ABSL_LOG_INTERNAL_DCHECK_LE_IMPL((val1), #val1, (val2), #val2) 146 #define DCHECK_LT(val1, val2) \ 147 ABSL_LOG_INTERNAL_DCHECK_LT_IMPL((val1), #val1, (val2), #val2) 148 #define DCHECK_GE(val1, val2) \ 149 ABSL_LOG_INTERNAL_DCHECK_GE_IMPL((val1), #val1, (val2), #val2) 150 #define DCHECK_GT(val1, val2) \ 151 ABSL_LOG_INTERNAL_DCHECK_GT_IMPL((val1), #val1, (val2), #val2) 152 153 // `CHECK_OK` and friends validate that the provided `absl::Status` or 154 // `absl::StatusOr<T>` is OK. If it isn't, they print a failure message that 155 // includes the actual status and terminate the program. 156 // 157 // As with all `DCHECK` variants, `DCHECK_OK` has no effect (not even 158 // evaluating its argument) if `NDEBUG` is enabled. 159 // 160 // Example: 161 // 162 // CHECK_OK(FunctionReturnsStatus(x, y, z)) << "oops!"; 163 // 164 // Might produce a message like: 165 // 166 // Check failed: FunctionReturnsStatus(x, y, z) is OK (ABORTED: timeout) oops! 167 #define CHECK_OK(status) ABSL_LOG_INTERNAL_CHECK_OK_IMPL((status), #status) 168 #define QCHECK_OK(status) ABSL_LOG_INTERNAL_QCHECK_OK_IMPL((status), #status) 169 #define DCHECK_OK(status) ABSL_LOG_INTERNAL_DCHECK_OK_IMPL((status), #status) 170 171 // `CHECK_STREQ` and friends provide `CHECK_EQ` functionality for C strings, 172 // i.e., null-terminated char arrays. The `CASE` versions are case-insensitive. 173 // 174 // Example: 175 // 176 // CHECK_STREQ(argv[0], "./skynet"); 177 // 178 // Note that both arguments may be temporary strings which are destroyed by the 179 // compiler at the end of the current full expression. 180 // 181 // Example: 182 // 183 // CHECK_STREQ(Foo().c_str(), Bar().c_str()); 184 #define CHECK_STREQ(s1, s2) \ 185 ABSL_LOG_INTERNAL_CHECK_STREQ_IMPL((s1), #s1, (s2), #s2) 186 #define CHECK_STRNE(s1, s2) \ 187 ABSL_LOG_INTERNAL_CHECK_STRNE_IMPL((s1), #s1, (s2), #s2) 188 #define CHECK_STRCASEEQ(s1, s2) \ 189 ABSL_LOG_INTERNAL_CHECK_STRCASEEQ_IMPL((s1), #s1, (s2), #s2) 190 #define CHECK_STRCASENE(s1, s2) \ 191 ABSL_LOG_INTERNAL_CHECK_STRCASENE_IMPL((s1), #s1, (s2), #s2) 192 #define QCHECK_STREQ(s1, s2) \ 193 ABSL_LOG_INTERNAL_QCHECK_STREQ_IMPL((s1), #s1, (s2), #s2) 194 #define QCHECK_STRNE(s1, s2) \ 195 ABSL_LOG_INTERNAL_QCHECK_STRNE_IMPL((s1), #s1, (s2), #s2) 196 #define QCHECK_STRCASEEQ(s1, s2) \ 197 ABSL_LOG_INTERNAL_QCHECK_STRCASEEQ_IMPL((s1), #s1, (s2), #s2) 198 #define QCHECK_STRCASENE(s1, s2) \ 199 ABSL_LOG_INTERNAL_QCHECK_STRCASENE_IMPL((s1), #s1, (s2), #s2) 200 #define DCHECK_STREQ(s1, s2) \ 201 ABSL_LOG_INTERNAL_DCHECK_STREQ_IMPL((s1), #s1, (s2), #s2) 202 #define DCHECK_STRNE(s1, s2) \ 203 ABSL_LOG_INTERNAL_DCHECK_STRNE_IMPL((s1), #s1, (s2), #s2) 204 #define DCHECK_STRCASEEQ(s1, s2) \ 205 ABSL_LOG_INTERNAL_DCHECK_STRCASEEQ_IMPL((s1), #s1, (s2), #s2) 206 #define DCHECK_STRCASENE(s1, s2) \ 207 ABSL_LOG_INTERNAL_DCHECK_STRCASENE_IMPL((s1), #s1, (s2), #s2) 208 209 #endif // ABSL_LOG_CHECK_H_