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Diffstat (limited to 'absl/log/check.h')
-rw-r--r-- | absl/log/check.h | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/absl/log/check.h b/absl/log/check.h new file mode 100644 index 00000000..30bf76a0 --- /dev/null +++ b/absl/log/check.h @@ -0,0 +1,227 @@ +// Copyright 2022 The Abseil Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// https://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. +// +// ----------------------------------------------------------------------------- +// File: log/check.h +// ----------------------------------------------------------------------------- +// +// This header declares a family of `CHECK` macros. +// +// `CHECK` macros terminate the program with a fatal error if the specified +// condition is not true. +// +// Except for those whose names begin with `DCHECK`, these macros are not +// controlled by `NDEBUG` (cf. `assert`), so the check will be executed +// regardless of compilation mode. `CHECK` and friends are thus useful for +// confirming invariants in situations where continuing to run would be worse +// than terminating, e.g., due to risk of data corruption or security +// compromise. It is also more robust and portable to deliberately terminate +// at a particular place with a useful message and backtrace than to assume some +// ultimately unspecified and unreliable crashing behavior (such as a +// "segmentation fault"). + +#ifndef ABSL_LOG_CHECK_H_ +#define ABSL_LOG_CHECK_H_ + +#include "absl/base/optimization.h" +#include "absl/log/internal/check_op.h" // IWYU pragma: export +#include "absl/log/internal/conditions.h" // IWYU pragma: export +#include "absl/log/internal/log_message.h" // IWYU pragma: export +#include "absl/log/internal/strip.h" // IWYU pragma: export + +// CHECK() +// +// `CHECK` terminates the program with a fatal error if `condition` is not true. +// +// The message may include additional information such as stack traces, when +// available. +// +// Example: +// +// CHECK(!cheese.empty()) << "Out of Cheese"; +// +// Might produce a message like: +// +// Check failed: !cheese.empty() Out of Cheese +#define CHECK(condition) \ + ABSL_LOG_INTERNAL_CONDITION_FATAL(STATELESS, \ + ABSL_PREDICT_FALSE(!(condition))) \ + ABSL_LOG_INTERNAL_CHECK(#condition).InternalStream() + +// QCHECK() +// +// `QCHECK` behaves like `CHECK` but does not print a full stack trace and does +// not run registered error handlers (as `QFATAL`). It is useful when the +// problem is definitely unrelated to program flow, e.g. when validating user +// input. +#define QCHECK(condition) \ + ABSL_LOG_INTERNAL_CONDITION_QFATAL(STATELESS, \ + ABSL_PREDICT_FALSE(!(condition))) \ + ABSL_LOG_INTERNAL_QCHECK(#condition).InternalStream() + +// PCHECK() +// +// `PCHECK` behaves like `CHECK` but appends a description of the current state +// of `errno` to the failure message. +// +// Example: +// +// int fd = open("/var/empty/missing", O_RDONLY); +// PCHECK(fd != -1) << "posix is difficult"; +// +// Might produce a message like: +// +// Check failed: fd != -1 posix is difficult: No such file or directory [2] +#define PCHECK(condition) CHECK(condition).WithPerror() + +// DCHECK() +// +// `DCHECK` behaves like `CHECK` in debug mode and does nothing otherwise (as +// `DLOG`). Unlike with `CHECK` (but as with `assert`), it is not safe to rely +// on evaluation of `condition`: when `NDEBUG` is enabled, DCHECK does not +// evaluate the condition. +#ifndef NDEBUG +#define DCHECK(condition) CHECK(condition) +#else +#define DCHECK(condition) CHECK(true || (condition)) +#endif + +// `CHECK_EQ` and friends are syntactic sugar for `CHECK(x == y)` that +// automatically output the expression being tested and the evaluated values on +// either side. +// +// Example: +// +// int x = 3, y = 5; +// CHECK_EQ(2 * x, y) << "oops!"; +// +// Might produce a message like: +// +// Check failed: 2 * x == y (6 vs. 5) oops! +// +// The values must implement the appropriate comparison operator as well as +// `operator<<(std::ostream&, ...)`. Care is taken to ensure that each +// argument is evaluated exactly once, and that anything which is legal to pass +// as a function argument is legal here. In particular, the arguments may be +// temporary expressions which will end up being destroyed at the end of the +// statement, +// +// Example: +// +// CHECK_EQ(std::string("abc")[1], 'b'); +// +// WARNING: Passing `NULL` as an argument to `CHECK_EQ` and similar macros does +// not compile. Use `nullptr` instead. +#define CHECK_EQ(val1, val2) \ + ABSL_LOG_INTERNAL_CHECK_OP(Check_EQ, ==, val1, val2) +#define CHECK_NE(val1, val2) \ + ABSL_LOG_INTERNAL_CHECK_OP(Check_NE, !=, val1, val2) +#define CHECK_LE(val1, val2) \ + ABSL_LOG_INTERNAL_CHECK_OP(Check_LE, <=, val1, val2) +#define CHECK_LT(val1, val2) ABSL_LOG_INTERNAL_CHECK_OP(Check_LT, <, val1, val2) +#define CHECK_GE(val1, val2) \ + ABSL_LOG_INTERNAL_CHECK_OP(Check_GE, >=, val1, val2) +#define CHECK_GT(val1, val2) ABSL_LOG_INTERNAL_CHECK_OP(Check_GT, >, val1, val2) +#define QCHECK_EQ(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_EQ, ==, val1, val2) +#define QCHECK_NE(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_NE, !=, val1, val2) +#define QCHECK_LE(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_LE, <=, val1, val2) +#define QCHECK_LT(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_LT, <, val1, val2) +#define QCHECK_GE(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_GE, >=, val1, val2) +#define QCHECK_GT(val1, val2) \ + ABSL_LOG_INTERNAL_QCHECK_OP(Check_GT, >, val1, val2) +#ifndef NDEBUG +#define DCHECK_EQ(val1, val2) CHECK_EQ(val1, val2) +#define DCHECK_NE(val1, val2) CHECK_NE(val1, val2) +#define DCHECK_LE(val1, val2) CHECK_LE(val1, val2) +#define DCHECK_LT(val1, val2) CHECK_LT(val1, val2) +#define DCHECK_GE(val1, val2) CHECK_GE(val1, val2) +#define DCHECK_GT(val1, val2) CHECK_GT(val1, val2) +#else // ndef NDEBUG +#define DCHECK_EQ(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#define DCHECK_NE(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#define DCHECK_LE(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#define DCHECK_LT(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#define DCHECK_GE(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#define DCHECK_GT(val1, val2) ABSL_LOG_INTERNAL_DCHECK_NOP(val1, val2) +#endif // def NDEBUG + +// `CHECK_OK` and friends validate that the provided `absl::Status` or +// `absl::StatusOr<T>` is OK. If it isn't, they print a failure message that +// includes the actual status. +// +// As with all `DCHECK` variants, `DCHECK_OK` has no effect (not even +// evaluating its argument) if `NDEBUG` is enabled. +// +// Example: +// +// CHECK_OK(FunctionReturnsStatus(x, y, z)) << "oops!"; +// +// Might produce a message like: +// +// Check failed: FunctionReturnsStatus(x, y, z) is OK (ABORTED: timeout) oops! +#define CHECK_OK(status) ABSL_LOG_INTERNAL_CHECK_OK(status) +#define QCHECK_OK(status) ABSL_LOG_INTERNAL_QCHECK_OK(status) +#ifndef NDEBUG +#define DCHECK_OK(status) ABSL_LOG_INTERNAL_CHECK_OK(status) +#else +#define DCHECK_OK(status) ABSL_LOG_INTERNAL_DCHECK_NOP(status, nullptr) +#endif + +// `CHECK_STREQ` and friends provide `CHECK_EQ` functionality for C strings, +// i.e., nul-terminated char arrays. The `CASE` versions are case-insensitive. +// +// Example: +// +// CHECK_STREQ(argv[0], "./skynet"); +// +// Note that both arguments may be temporary strings which are destroyed by the +// compiler at the end of the current full expression. +// +// Example: +// +// CHECK_STREQ(Foo().c_str(), Bar().c_str()); +#define CHECK_STREQ(s1, s2) \ + ABSL_LOG_INTERNAL_CHECK_STROP(strcmp, ==, true, s1, s2) +#define CHECK_STRNE(s1, s2) \ + ABSL_LOG_INTERNAL_CHECK_STROP(strcmp, !=, false, s1, s2) +#define CHECK_STRCASEEQ(s1, s2) \ + ABSL_LOG_INTERNAL_CHECK_STROP(strcasecmp, ==, true, s1, s2) +#define CHECK_STRCASENE(s1, s2) \ + ABSL_LOG_INTERNAL_CHECK_STROP(strcasecmp, !=, false, s1, s2) +#define QCHECK_STREQ(s1, s2) \ + ABSL_LOG_INTERNAL_QCHECK_STROP(strcmp, ==, true, s1, s2) +#define QCHECK_STRNE(s1, s2) \ + ABSL_LOG_INTERNAL_QCHECK_STROP(strcmp, !=, false, s1, s2) +#define QCHECK_STRCASEEQ(s1, s2) \ + ABSL_LOG_INTERNAL_QCHECK_STROP(strcasecmp, ==, true, s1, s2) +#define QCHECK_STRCASENE(s1, s2) \ + ABSL_LOG_INTERNAL_QCHECK_STROP(strcasecmp, !=, false, s1, s2) +#ifndef NDEBUG +#define DCHECK_STREQ(s1, s2) CHECK_STREQ(s1, s2) +#define DCHECK_STRCASEEQ(s1, s2) CHECK_STRCASEEQ(s1, s2) +#define DCHECK_STRNE(s1, s2) CHECK_STRNE(s1, s2) +#define DCHECK_STRCASENE(s1, s2) CHECK_STRCASENE(s1, s2) +#else // ndef NDEBUG +#define DCHECK_STREQ(s1, s2) ABSL_LOG_INTERNAL_DCHECK_NOP(s1, s2) +#define DCHECK_STRCASEEQ(s1, s2) ABSL_LOG_INTERNAL_DCHECK_NOP(s1, s2) +#define DCHECK_STRNE(s1, s2) ABSL_LOG_INTERNAL_DCHECK_NOP(s1, s2) +#define DCHECK_STRCASENE(s1, s2) ABSL_LOG_INTERNAL_DCHECK_NOP(s1, s2) +#endif // def NDEBUG + +#endif // ABSL_LOG_CHECK_H_ |