logging.h revision e5f13e57ff8fa36342beb33830b3ec5942a61cca 
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 <memory>
21#include <ostream>
22
23#include "base/macros.h"
24
25namespace art {
26
27enum LogSeverity {
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.
39struct LogVerbosity {
40  bool class_linker;  // Enabled with "-verbose:class".
41  bool compiler;
42  bool gc;
43  bool heap;
44  bool jdwp;
45  bool jit;
46  bool jni;
47  bool monitor;
48  bool profiler;
49  bool signals;
50  bool startup;
51  bool third_party_jni;  // Enabled with "-verbose:third-party-jni".
52  bool threads;
53  bool verifier;
54};
55
56// Global log verbosity setting, initialized by InitLogging.
57extern LogVerbosity gLogVerbosity;
58
59// 0 if not abort, non-zero if an abort is in progress. Used on fatal exit to prevents recursive
60// aborts. Global declaration allows us to disable some error checking to ensure fatal shutdown
61// makes forward progress.
62extern unsigned int gAborting;
63
64// Configure logging based on ANDROID_LOG_TAGS environment variable.
65// We need to parse a string that looks like
66//
67//      *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
68//
69// The tag (or '*' for the global level) comes first, followed by a colon
70// and a letter indicating the minimum priority level we're expected to log.
71// This can be used to reveal or conceal logs with specific tags.
72extern void InitLogging(char* argv[]);
73
74// Returns the command line used to invoke the current tool or nullptr if InitLogging hasn't been
75// performed.
76extern const char* GetCmdLine();
77
78// The command used to start the ART runtime, such as "/system/bin/dalvikvm". If InitLogging hasn't
79// been performed then just returns "art"
80extern const char* ProgramInvocationName();
81
82// A short version of the command used to start the ART runtime, such as "dalvikvm". If InitLogging
83// hasn't been performed then just returns "art"
84extern const char* ProgramInvocationShortName();
85
86// Logs a message to logcat on Android otherwise to stderr. If the severity is FATAL it also causes
87// an abort. For example: LOG(FATAL) << "We didn't expect to reach here";
88#define LOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, -1).stream()
89
90// A variant of LOG that also logs the current errno value. To be used when library calls fail.
91#define PLOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, errno).stream()
92
93// Marker that code is yet to be implemented.
94#define UNIMPLEMENTED(level) LOG(level) << __PRETTY_FUNCTION__ << " unimplemented "
95
96// Is verbose logging enabled for the given module? Where the module is defined in LogVerbosity.
97#define VLOG_IS_ON(module) UNLIKELY(::art::gLogVerbosity.module)
98
99// Variant of LOG that logs when verbose logging is enabled for a module. For example,
100// VLOG(jni) << "A JNI operation was performed";
101#define VLOG(module) \
102  if (VLOG_IS_ON(module)) \
103    ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
104
105// Return the stream associated with logging for the given module.
106#define VLOG_STREAM(module) ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
107
108// Check whether condition x holds and LOG(FATAL) if not. The value of the expression x is only
109// evaluated once. Extra logging can be appended using << after. For example,
110// CHECK(false == true) results in a log message of "Check failed: false == true".
111#define CHECK(x) \
112  if (UNLIKELY(!(x))) \
113    ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
114        << "Check failed: " #x << " "
115
116// Helper for CHECK_xx(x,y) macros.
117#define CHECK_OP(LHS, RHS, OP) \
118  for (auto _values = ::art::MakeEagerEvaluator(LHS, RHS); \
119       UNLIKELY(!(_values.lhs OP _values.rhs)); /* empty */) \
120    ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
121        << "Check failed: " << #LHS << " " << #OP << " " << #RHS \
122        << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
123
124
125// Check whether a condition holds between x and y, LOG(FATAL) if not. The value of the expressions
126// x and y is evaluated once. Extra logging can be appended using << after. For example,
127// CHECK_NE(0 == 1, false) results in "Check failed: false != false (0==1=false, false=false) ".
128#define CHECK_EQ(x, y) CHECK_OP(x, y, ==)
129#define CHECK_NE(x, y) CHECK_OP(x, y, !=)
130#define CHECK_LE(x, y) CHECK_OP(x, y, <=)
131#define CHECK_LT(x, y) CHECK_OP(x, y, <)
132#define CHECK_GE(x, y) CHECK_OP(x, y, >=)
133#define CHECK_GT(x, y) CHECK_OP(x, y, >)
134
135// Helper for CHECK_STRxx(s1,s2) macros.
136#define CHECK_STROP(s1, s2, sense) \
137  if (UNLIKELY((strcmp(s1, s2) == 0) != sense)) \
138    LOG(::art::FATAL) << "Check failed: " \
139        << "\"" << s1 << "\"" \
140        << (sense ? " == " : " != ") \
141        << "\"" << s2 << "\""
142
143// Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
144#define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
145#define CHECK_STRNE(s1, s2) CHECK_STROP(s1, s2, false)
146
147// Perform the pthread function call(args), LOG(FATAL) on error.
148#define CHECK_PTHREAD_CALL(call, args, what) \
149  do { \
150    int rc = call args; \
151    if (rc != 0) { \
152      errno = rc; \
153      PLOG(::art::FATAL) << # call << " failed for " << what; \
154    } \
155  } while (false)
156
157// CHECK that can be used in a constexpr function. For example,
158//    constexpr int half(int n) {
159//      return
160//          DCHECK_CONSTEXPR(n >= 0, , 0)
161//          CHECK_CONSTEXPR((n & 1) == 0), << "Extra debugging output: n = " << n, 0)
162//          n / 2;
163//    }
164#define CHECK_CONSTEXPR(x, out, dummy) \
165  (UNLIKELY(!(x))) ? (LOG(::art::FATAL) << "Check failed: " << #x out, dummy) :
166
167
168// DCHECKs are debug variants of CHECKs only enabled in debug builds. Generally CHECK should be
169// used unless profiling identifies a CHECK as being in performance critical code.
170#if defined(NDEBUG)
171static constexpr bool kEnableDChecks = false;
172#else
173static constexpr bool kEnableDChecks = true;
174#endif
175
176#define DCHECK(x) if (::art::kEnableDChecks) CHECK(x)
177#define DCHECK_EQ(x, y) if (::art::kEnableDChecks) CHECK_EQ(x, y)
178#define DCHECK_NE(x, y) if (::art::kEnableDChecks) CHECK_NE(x, y)
179#define DCHECK_LE(x, y) if (::art::kEnableDChecks) CHECK_LE(x, y)
180#define DCHECK_LT(x, y) if (::art::kEnableDChecks) CHECK_LT(x, y)
181#define DCHECK_GE(x, y) if (::art::kEnableDChecks) CHECK_GE(x, y)
182#define DCHECK_GT(x, y) if (::art::kEnableDChecks) CHECK_GT(x, y)
183#define DCHECK_STREQ(s1, s2) if (::art::kEnableDChecks) CHECK_STREQ(s1, s2)
184#define DCHECK_STRNE(s1, s2) if (::art::kEnableDChecks) CHECK_STRNE(s1, s2)
185#if defined(NDEBUG)
186#define DCHECK_CONSTEXPR(x, out, dummy)
187#else
188#define DCHECK_CONSTEXPR(x, out, dummy) CHECK_CONSTEXPR(x, out, dummy)
189#endif
190
191// Temporary class created to evaluate the LHS and RHS, used with MakeEagerEvaluator to infer the
192// types of LHS and RHS.
193template <typename LHS, typename RHS>
194struct EagerEvaluator {
195  EagerEvaluator(LHS l, RHS r) : lhs(l), rhs(r) { }
196  LHS lhs;
197  RHS rhs;
198};
199
200// Helper function for CHECK_xx.
201template <typename LHS, typename RHS>
202static inline EagerEvaluator<LHS, RHS> MakeEagerEvaluator(LHS lhs, RHS rhs) {
203  return EagerEvaluator<LHS, RHS>(lhs, rhs);
204}
205
206// Explicitly instantiate EagerEvalue for pointers so that char*s aren't treated as strings. To
207// compare strings use CHECK_STREQ and CHECK_STRNE. We rely on signed/unsigned warnings to
208// protect you against combinations not explicitly listed below.
209#define EAGER_PTR_EVALUATOR(T1, T2) \
210  template <> struct EagerEvaluator<T1, T2> { \
211    EagerEvaluator(T1 l, T2 r) \
212        : lhs(reinterpret_cast<const void*>(l)), \
213          rhs(reinterpret_cast<const void*>(r)) { } \
214    const void* lhs; \
215    const void* rhs; \
216  }
217EAGER_PTR_EVALUATOR(const char*, const char*);
218EAGER_PTR_EVALUATOR(const char*, char*);
219EAGER_PTR_EVALUATOR(char*, const char*);
220EAGER_PTR_EVALUATOR(char*, char*);
221EAGER_PTR_EVALUATOR(const unsigned char*, const unsigned char*);
222EAGER_PTR_EVALUATOR(const unsigned char*, unsigned char*);
223EAGER_PTR_EVALUATOR(unsigned char*, const unsigned char*);
224EAGER_PTR_EVALUATOR(unsigned char*, unsigned char*);
225EAGER_PTR_EVALUATOR(const signed char*, const signed char*);
226EAGER_PTR_EVALUATOR(const signed char*, signed char*);
227EAGER_PTR_EVALUATOR(signed char*, const signed char*);
228EAGER_PTR_EVALUATOR(signed char*, signed char*);
229
230// Data for the log message, not stored in LogMessage to avoid increasing the stack size.
231class LogMessageData;
232
233// A LogMessage is a temporarily scoped object used by LOG and the unlikely part of a CHECK. The
234// destructor will abort if the severity is FATAL.
235class LogMessage {
236 public:
237  LogMessage(const char* file, unsigned int line, LogSeverity severity, int error);
238
239  ~LogMessage();  // TODO: enable LOCKS_EXCLUDED(Locks::logging_lock_).
240
241  // Returns the stream associated with the message, the LogMessage performs output when it goes
242  // out of scope.
243  std::ostream& stream();
244
245  // The routine that performs the actual logging.
246  static void LogLine(const char* file, unsigned int line, LogSeverity severity, const char* msg);
247
248  // A variant of the above for use with little stack.
249  static void LogLineLowStack(const char* file, unsigned int line, LogSeverity severity,
250                              const char* msg);
251
252 private:
253  const std::unique_ptr<LogMessageData> data_;
254
255  DISALLOW_COPY_AND_ASSIGN(LogMessage);
256};
257
258// Allows to temporarily change the minimum severity level for logging.
259class ScopedLogSeverity {
260 public:
261  explicit ScopedLogSeverity(LogSeverity level);
262  ~ScopedLogSeverity();
263
264 private:
265  LogSeverity old_;
266};
267
268}  // namespace art
269
270#endif  // ART_RUNTIME_BASE_LOGGING_H_
271