1 /*
2  * Copyright (C) 2011 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #ifndef ART_RUNTIME_BASE_LOGGING_H_
18 #define ART_RUNTIME_BASE_LOGGING_H_
19 
20 #include <ostream>
21 
22 #include "base/macros.h"
23 
24 namespace art {
25 
26 enum LogSeverity {
27   NONE,            // Fake level, don't log at all.
28   VERBOSE,
29   DEBUG,
30   INFO,
31   WARNING,
32   ERROR,
33   FATAL,
34   INTERNAL_FATAL,  // For Runtime::Abort.
35 };
36 
37 // The members of this struct are the valid arguments to VLOG and VLOG_IS_ON in code,
38 // and the "-verbose:" command line argument.
39 struct LogVerbosity {
40   bool class_linker;  // Enabled with "-verbose:class".
41   bool collector;
42   bool compiler;
43   bool deopt;
44   bool gc;
45   bool heap;
46   bool jdwp;
47   bool jit;
48   bool jni;
49   bool monitor;
50   bool oat;
51   bool profiler;
52   bool signals;
53   bool simulator;
54   bool startup;
55   bool third_party_jni;  // Enabled with "-verbose:third-party-jni".
56   bool threads;
57   bool verifier;
58   bool image;
59   bool systrace_lock_logging;  // Enabled with "-verbose:sys-locks".
60 };
61 
62 // Global log verbosity setting, initialized by InitLogging.
63 extern LogVerbosity gLogVerbosity;
64 
65 // 0 if not abort, non-zero if an abort is in progress. Used on fatal exit to prevents recursive
66 // aborts. Global declaration allows us to disable some error checking to ensure fatal shutdown
67 // makes forward progress.
68 extern unsigned int gAborting;
69 
70 // Configure logging based on ANDROID_LOG_TAGS environment variable.
71 // We need to parse a string that looks like
72 //
73 //      *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
74 //
75 // The tag (or '*' for the global level) comes first, followed by a colon
76 // and a letter indicating the minimum priority level we're expected to log.
77 // This can be used to reveal or conceal logs with specific tags.
78 extern void InitLogging(char* argv[]);
79 
80 // Returns the command line used to invoke the current tool or null if InitLogging hasn't been
81 // performed.
82 extern const char* GetCmdLine();
83 
84 // The command used to start the ART runtime, such as "/system/bin/dalvikvm". If InitLogging hasn't
85 // been performed then just returns "art"
86 extern const char* ProgramInvocationName();
87 
88 // A short version of the command used to start the ART runtime, such as "dalvikvm". If InitLogging
89 // hasn't been performed then just returns "art"
90 extern const char* ProgramInvocationShortName();
91 
92 // Logs a message to logcat on Android otherwise to stderr. If the severity is FATAL it also causes
93 // an abort. For example: LOG(FATAL) << "We didn't expect to reach here";
94 #define LOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, -1).stream()
95 
96 // A variant of LOG that also logs the current errno value. To be used when library calls fail.
97 #define PLOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, errno).stream()
98 
99 // Marker that code is yet to be implemented.
100 #define UNIMPLEMENTED(level) LOG(level) << __PRETTY_FUNCTION__ << " unimplemented "
101 
102 // Is verbose logging enabled for the given module? Where the module is defined in LogVerbosity.
103 #define VLOG_IS_ON(module) UNLIKELY(::art::gLogVerbosity.module)
104 
105 // Variant of LOG that logs when verbose logging is enabled for a module. For example,
106 // VLOG(jni) << "A JNI operation was performed";
107 #define VLOG(module) \
108   if (VLOG_IS_ON(module)) \
109     ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
110 
111 // Return the stream associated with logging for the given module.
112 #define VLOG_STREAM(module) ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
113 
114 // Check whether condition x holds and LOG(FATAL) if not. The value of the expression x is only
115 // evaluated once. Extra logging can be appended using << after. For example,
116 // CHECK(false == true) results in a log message of "Check failed: false == true".
117 #define CHECK(x) \
118   if (UNLIKELY(!(x))) \
119     ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
120         << "Check failed: " #x << " "
121 
122 // Helper for CHECK_xx(x,y) macros.
123 #define CHECK_OP(LHS, RHS, OP) \
124   for (auto _values = ::art::MakeEagerEvaluator(LHS, RHS); \
125        UNLIKELY(!(_values.lhs OP _values.rhs)); /* empty */) \
126     ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
127         << "Check failed: " << #LHS << " " << #OP << " " << #RHS \
128         << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
129 
130 
131 // Check whether a condition holds between x and y, LOG(FATAL) if not. The value of the expressions
132 // x and y is evaluated once. Extra logging can be appended using << after. For example,
133 // CHECK_NE(0 == 1, false) results in "Check failed: false != false (0==1=false, false=false) ".
134 #define CHECK_EQ(x, y) CHECK_OP(x, y, ==)
135 #define CHECK_NE(x, y) CHECK_OP(x, y, !=)
136 #define CHECK_LE(x, y) CHECK_OP(x, y, <=)
137 #define CHECK_LT(x, y) CHECK_OP(x, y, <)
138 #define CHECK_GE(x, y) CHECK_OP(x, y, >=)
139 #define CHECK_GT(x, y) CHECK_OP(x, y, >)
140 
141 // Helper for CHECK_STRxx(s1,s2) macros.
142 #define CHECK_STROP(s1, s2, sense) \
143   if (UNLIKELY((strcmp(s1, s2) == 0) != sense)) \
144     LOG(::art::FATAL) << "Check failed: " \
145         << "\"" << s1 << "\"" \
146         << (sense ? " == " : " != ") \
147         << "\"" << s2 << "\""
148 
149 // Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
150 #define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
151 #define CHECK_STRNE(s1, s2) CHECK_STROP(s1, s2, false)
152 
153 // Perform the pthread function call(args), LOG(FATAL) on error.
154 #define CHECK_PTHREAD_CALL(call, args, what) \
155   do { \
156     int rc = call args; \
157     if (rc != 0) { \
158       errno = rc; \
159       PLOG(::art::FATAL) << # call << " failed for " << what; \
160     } \
161   } while (false)
162 
163 // CHECK that can be used in a constexpr function. For example,
164 //    constexpr int half(int n) {
165 //      return
166 //          DCHECK_CONSTEXPR(n >= 0, , 0)
167 //          CHECK_CONSTEXPR((n & 1) == 0), << "Extra debugging output: n = " << n, 0)
168 //          n / 2;
169 //    }
170 #define CHECK_CONSTEXPR(x, out, dummy) \
171   (UNLIKELY(!(x))) ? (LOG(::art::FATAL) << "Check failed: " << #x out, dummy) :
172 
173 
174 // DCHECKs are debug variants of CHECKs only enabled in debug builds. Generally CHECK should be
175 // used unless profiling identifies a CHECK as being in performance critical code.
176 #if defined(NDEBUG)
177 static constexpr bool kEnableDChecks = false;
178 #else
179 static constexpr bool kEnableDChecks = true;
180 #endif
181 
182 #define DCHECK(x) if (::art::kEnableDChecks) CHECK(x)
183 #define DCHECK_EQ(x, y) if (::art::kEnableDChecks) CHECK_EQ(x, y)
184 #define DCHECK_NE(x, y) if (::art::kEnableDChecks) CHECK_NE(x, y)
185 #define DCHECK_LE(x, y) if (::art::kEnableDChecks) CHECK_LE(x, y)
186 #define DCHECK_LT(x, y) if (::art::kEnableDChecks) CHECK_LT(x, y)
187 #define DCHECK_GE(x, y) if (::art::kEnableDChecks) CHECK_GE(x, y)
188 #define DCHECK_GT(x, y) if (::art::kEnableDChecks) CHECK_GT(x, y)
189 #define DCHECK_STREQ(s1, s2) if (::art::kEnableDChecks) CHECK_STREQ(s1, s2)
190 #define DCHECK_STRNE(s1, s2) if (::art::kEnableDChecks) CHECK_STRNE(s1, s2)
191 #if defined(NDEBUG)
192 #define DCHECK_CONSTEXPR(x, out, dummy)
193 #else
194 #define DCHECK_CONSTEXPR(x, out, dummy) CHECK_CONSTEXPR(x, out, dummy)
195 #endif
196 
197 // Temporary class created to evaluate the LHS and RHS, used with MakeEagerEvaluator to infer the
198 // types of LHS and RHS.
199 template <typename LHS, typename RHS>
200 struct EagerEvaluator {
EagerEvaluatorEagerEvaluator201   EagerEvaluator(LHS l, RHS r) : lhs(l), rhs(r) { }
202   LHS lhs;
203   RHS rhs;
204 };
205 
206 // Helper function for CHECK_xx.
207 template <typename LHS, typename RHS>
MakeEagerEvaluator(LHS lhs,RHS rhs)208 static inline EagerEvaluator<LHS, RHS> MakeEagerEvaluator(LHS lhs, RHS rhs) {
209   return EagerEvaluator<LHS, RHS>(lhs, rhs);
210 }
211 
212 // Explicitly instantiate EagerEvalue for pointers so that char*s aren't treated as strings. To
213 // compare strings use CHECK_STREQ and CHECK_STRNE. We rely on signed/unsigned warnings to
214 // protect you against combinations not explicitly listed below.
215 #define EAGER_PTR_EVALUATOR(T1, T2) \
216   template <> struct EagerEvaluator<T1, T2> { \
217     EagerEvaluator(T1 l, T2 r) \
218         : lhs(reinterpret_cast<const void*>(l)), \
219           rhs(reinterpret_cast<const void*>(r)) { } \
220     const void* lhs; \
221     const void* rhs; \
222   }
223 EAGER_PTR_EVALUATOR(const char*, const char*);
224 EAGER_PTR_EVALUATOR(const char*, char*);
225 EAGER_PTR_EVALUATOR(char*, const char*);
226 EAGER_PTR_EVALUATOR(char*, char*);
227 EAGER_PTR_EVALUATOR(const unsigned char*, const unsigned char*);
228 EAGER_PTR_EVALUATOR(const unsigned char*, unsigned char*);
229 EAGER_PTR_EVALUATOR(unsigned char*, const unsigned char*);
230 EAGER_PTR_EVALUATOR(unsigned char*, unsigned char*);
231 EAGER_PTR_EVALUATOR(const signed char*, const signed char*);
232 EAGER_PTR_EVALUATOR(const signed char*, signed char*);
233 EAGER_PTR_EVALUATOR(signed char*, const signed char*);
234 EAGER_PTR_EVALUATOR(signed char*, signed char*);
235 
236 // Data for the log message, not stored in LogMessage to avoid increasing the stack size.
237 class LogMessageData;
238 
239 // A LogMessage is a temporarily scoped object used by LOG and the unlikely part of a CHECK. The
240 // destructor will abort if the severity is FATAL.
241 class LogMessage {
242  public:
243   LogMessage(const char* file, unsigned int line, LogSeverity severity, int error);
244 
245   ~LogMessage();  // TODO: enable REQUIRES(!Locks::logging_lock_).
246 
247   // Returns the stream associated with the message, the LogMessage performs output when it goes
248   // out of scope.
249   std::ostream& stream();
250 
251   // The routine that performs the actual logging.
252   static void LogLine(const char* file, unsigned int line, LogSeverity severity, const char* msg);
253 
254   // A variant of the above for use with little stack.
255   static void LogLineLowStack(const char* file, unsigned int line, LogSeverity severity,
256                               const char* msg);
257 
258  private:
259   const std::unique_ptr<LogMessageData> data_;
260 
261   DISALLOW_COPY_AND_ASSIGN(LogMessage);
262 };
263 
264 // Allows to temporarily change the minimum severity level for logging.
265 class ScopedLogSeverity {
266  public:
267   explicit ScopedLogSeverity(LogSeverity level);
268   ~ScopedLogSeverity();
269 
270  private:
271   LogSeverity old_;
272 };
273 
274 }  // namespace art
275 
276 #endif  // ART_RUNTIME_BASE_LOGGING_H_
277