1 // Copyright 2020 The Chromium Authors
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef BASE_ALLOCATOR_PARTITION_ALLOCATOR_PARTITION_ALLOC_BASE_CHECK_H_
6 #define BASE_ALLOCATOR_PARTITION_ALLOCATOR_PARTITION_ALLOC_BASE_CHECK_H_
7
8 #include <iosfwd>
9
10 #include "base/allocator/partition_allocator/partition_alloc_base/compiler_specific.h"
11 #include "base/allocator/partition_allocator/partition_alloc_base/component_export.h"
12 #include "base/allocator/partition_allocator/partition_alloc_base/debug/debugging_buildflags.h"
13 #include "base/allocator/partition_allocator/partition_alloc_base/immediate_crash.h"
14
15 // This header defines the CHECK, DCHECK, and DPCHECK macros.
16 //
17 // CHECK dies with a fatal error if its condition is not true. It is not
18 // controlled by NDEBUG, so the check will be executed regardless of compilation
19 // mode.
20 //
21 // DCHECK, the "debug mode" check, is enabled depending on NDEBUG and
22 // DCHECK_ALWAYS_ON, and its severity depends on DCHECK_IS_CONFIGURABLE.
23 //
24 // (D)PCHECK is like (D)CHECK, but includes the system error code (c.f.
25 // perror(3)).
26 //
27 // Additional information can be streamed to these macros and will be included
28 // in the log output if the condition doesn't hold (you may need to include
29 // <ostream>):
30 //
31 // CHECK(condition) << "Additional info.";
32 //
33 // The condition is evaluated exactly once. Even in build modes where e.g.
34 // DCHECK is disabled, the condition and any stream arguments are still
35 // referenced to avoid warnings about unused variables and functions.
36 //
37 // For the (D)CHECK_EQ, etc. macros, see base/check_op.h. However, that header
38 // is *significantly* larger than check.h, so try to avoid including it in
39 // header files.
40
41 namespace partition_alloc::internal::logging {
42
43 // Class used to explicitly ignore an ostream, and optionally a boolean value.
44 class VoidifyStream {
45 public:
46 VoidifyStream() = default;
VoidifyStream(bool ignored)47 explicit VoidifyStream(bool ignored) {}
48
49 // This operator has lower precedence than << but higher than ?:
50 void operator&(std::ostream&) {}
51 };
52
53 // Helper macro which avoids evaluating the arguments to a stream if the
54 // condition is false.
55 #define PA_LAZY_CHECK_STREAM(stream, condition) \
56 !(condition) \
57 ? (void)0 \
58 : ::partition_alloc::internal::logging::VoidifyStream() & (stream)
59
60 // Macro which uses but does not evaluate expr and any stream parameters.
61 #define PA_EAT_CHECK_STREAM_PARAMS(expr) \
62 true ? (void)0 \
63 : ::partition_alloc::internal::logging::VoidifyStream(expr) & \
64 (*::partition_alloc::internal::logging::g_swallow_stream)
65 PA_COMPONENT_EXPORT(PARTITION_ALLOC) extern std::ostream* g_swallow_stream;
66
67 class LogMessage;
68
69 // Class used for raising a check error upon destruction.
PA_COMPONENT_EXPORT(PARTITION_ALLOC)70 class PA_COMPONENT_EXPORT(PARTITION_ALLOC) CheckError {
71 public:
72 static CheckError Check(const char* file, int line, const char* condition);
73
74 static CheckError DCheck(const char* file, int line, const char* condition);
75
76 static CheckError PCheck(const char* file, int line, const char* condition);
77 static CheckError PCheck(const char* file, int line);
78
79 static CheckError DPCheck(const char* file, int line, const char* condition);
80
81 static CheckError NotImplemented(const char* file,
82 int line,
83 const char* function);
84
85 // Stream for adding optional details to the error message.
86 std::ostream& stream();
87
88 PA_NOMERGE ~CheckError();
89
90 CheckError(const CheckError& other) = delete;
91 CheckError& operator=(const CheckError& other) = delete;
92 CheckError(CheckError&& other) = default;
93 CheckError& operator=(CheckError&& other) = default;
94
95 private:
96 explicit CheckError(LogMessage* log_message);
97
98 LogMessage* log_message_;
99 };
100
101 #if defined(OFFICIAL_BUILD) && !defined(NDEBUG)
102 #error "Debug builds are not expected to be optimized as official builds."
103 #endif // defined(OFFICIAL_BUILD) && !defined(NDEBUG)
104
105 #if defined(OFFICIAL_BUILD) && !BUILDFLAG(PA_DCHECK_IS_ON)
106
107 // Discard log strings to reduce code bloat.
108 //
109 // This is not calling BreakDebugger since this is called frequently, and
110 // calling an out-of-line function instead of a noreturn inline macro prevents
111 // compiler optimizations.
112 #define PA_BASE_CHECK(condition) \
113 PA_UNLIKELY(!(condition)) ? PA_IMMEDIATE_CRASH() \
114 : PA_EAT_CHECK_STREAM_PARAMS()
115
116 // TODO(1151236): base/test/gtest_util.h uses CHECK_WILL_STREAM(). After
117 // copying (or removing) gtest_util.h and removing gtest_uti.h from partition
118 // allocator's DEPS, rename or remove CHECK_WILL_STREAM().
119 #define CHECK_WILL_STREAM() false
120
121 #define PA_BASE_PCHECK(condition) \
122 PA_LAZY_CHECK_STREAM( \
123 ::partition_alloc::internal::logging::CheckError::PCheck(__FILE__, \
124 __LINE__) \
125 .stream(), \
126 PA_UNLIKELY(!(condition)))
127
128 #else
129
130 #define PA_BASE_CHECK(condition) \
131 PA_LAZY_CHECK_STREAM( \
132 ::partition_alloc::internal::logging::CheckError::Check( \
133 __FILE__, __LINE__, #condition) \
134 .stream(), \
135 !PA_ANALYZER_ASSUME_TRUE(condition))
136
137 #define CHECK_WILL_STREAM() true
138
139 #define PA_BASE_PCHECK(condition) \
140 PA_LAZY_CHECK_STREAM( \
141 ::partition_alloc::internal::logging::CheckError::PCheck( \
142 __FILE__, __LINE__, #condition) \
143 .stream(), \
144 !PA_ANALYZER_ASSUME_TRUE(condition))
145
146 #endif
147
148 #if BUILDFLAG(PA_DCHECK_IS_ON)
149
150 #define PA_BASE_DCHECK(condition) \
151 PA_LAZY_CHECK_STREAM( \
152 ::partition_alloc::internal::logging::CheckError::DCheck( \
153 __FILE__, __LINE__, #condition) \
154 .stream(), \
155 !PA_ANALYZER_ASSUME_TRUE(condition))
156
157 #define PA_BASE_DPCHECK(condition) \
158 PA_LAZY_CHECK_STREAM( \
159 ::partition_alloc::internal::logging::CheckError::DPCheck( \
160 __FILE__, __LINE__, #condition) \
161 .stream(), \
162 !PA_ANALYZER_ASSUME_TRUE(condition))
163
164 #else
165
166 #define PA_BASE_DCHECK(condition) PA_EAT_CHECK_STREAM_PARAMS(!(condition))
167 #define PA_BASE_DPCHECK(condition) PA_EAT_CHECK_STREAM_PARAMS(!(condition))
168
169 #endif
170
171 // Async signal safe checking mechanism.
172 PA_COMPONENT_EXPORT(PARTITION_ALLOC) void RawCheck(const char* message);
173 PA_COMPONENT_EXPORT(PARTITION_ALLOC) void RawError(const char* message);
174 #define PA_RAW_CHECK(condition) \
175 do { \
176 if (!(condition)) \
177 ::partition_alloc::internal::logging::RawCheck( \
178 "Check failed: " #condition "\n"); \
179 } while (0)
180
181 } // namespace partition_alloc::internal::logging
182
183 #endif // BASE_ALLOCATOR_PARTITION_ALLOCATOR_PARTITION_ALLOC_BASE_CHECK_H_
184