logging.h revision 2cebb24bfc3247d3e9be138a3350106737455918 
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 oat;
49  bool profiler;
50  bool signals;
51  bool startup;
52  bool third_party_jni;  // Enabled with "-verbose:third-party-jni".
53  bool threads;
54  bool verifier;
55};
56
57// Global log verbosity setting, initialized by InitLogging.
58extern LogVerbosity gLogVerbosity;
59
60// 0 if not abort, non-zero if an abort is in progress. Used on fatal exit to prevents recursive
61// aborts. Global declaration allows us to disable some error checking to ensure fatal shutdown
62// makes forward progress.
63extern unsigned int gAborting;
64
65// Configure logging based on ANDROID_LOG_TAGS environment variable.
66// We need to parse a string that looks like
67//
68//      *:v jdwp:d dalvikvm:d dalvikvm-gc:i dalvikvmi:i
69//
70// The tag (or '*' for the global level) comes first, followed by a colon
71// and a letter indicating the minimum priority level we're expected to log.
72// This can be used to reveal or conceal logs with specific tags.
73extern void InitLogging(char* argv[]);
74
75// Returns the command line used to invoke the current tool or null if InitLogging hasn't been
76// performed.
77extern const char* GetCmdLine();
78
79// The command used to start the ART runtime, such as "/system/bin/dalvikvm". If InitLogging hasn't
80// been performed then just returns "art"
81extern const char* ProgramInvocationName();
82
83// A short version of the command used to start the ART runtime, such as "dalvikvm". If InitLogging
84// hasn't been performed then just returns "art"
85extern const char* ProgramInvocationShortName();
86
87// Logs a message to logcat on Android otherwise to stderr. If the severity is FATAL it also causes
88// an abort. For example: LOG(FATAL) << "We didn't expect to reach here";
89#define LOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, -1).stream()
90
91// A variant of LOG that also logs the current errno value. To be used when library calls fail.
92#define PLOG(severity) ::art::LogMessage(__FILE__, __LINE__, severity, errno).stream()
93
94// Marker that code is yet to be implemented.
95#define UNIMPLEMENTED(level) LOG(level) << __PRETTY_FUNCTION__ << " unimplemented "
96
97// Is verbose logging enabled for the given module? Where the module is defined in LogVerbosity.
98#define VLOG_IS_ON(module) UNLIKELY(::art::gLogVerbosity.module)
99
100// Variant of LOG that logs when verbose logging is enabled for a module. For example,
101// VLOG(jni) << "A JNI operation was performed";
102#define VLOG(module) \
103  if (VLOG_IS_ON(module)) \
104    ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
105
106// Return the stream associated with logging for the given module.
107#define VLOG_STREAM(module) ::art::LogMessage(__FILE__, __LINE__, INFO, -1).stream()
108
109// Check whether condition x holds and LOG(FATAL) if not. The value of the expression x is only
110// evaluated once. Extra logging can be appended using << after. For example,
111// CHECK(false == true) results in a log message of "Check failed: false == true".
112#define CHECK(x) \
113  if (UNLIKELY(!(x))) \
114    ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
115        << "Check failed: " #x << " "
116
117// Helper for CHECK_xx(x,y) macros.
118#define CHECK_OP(LHS, RHS, OP) \
119  for (auto _values = ::art::MakeEagerEvaluator(LHS, RHS); \
120       UNLIKELY(!(_values.lhs OP _values.rhs)); /* empty */) \
121    ::art::LogMessage(__FILE__, __LINE__, ::art::FATAL, -1).stream() \
122        << "Check failed: " << #LHS << " " << #OP << " " << #RHS \
123        << " (" #LHS "=" << _values.lhs << ", " #RHS "=" << _values.rhs << ") "
124
125
126// Check whether a condition holds between x and y, LOG(FATAL) if not. The value of the expressions
127// x and y is evaluated once. Extra logging can be appended using << after. For example,
128// CHECK_NE(0 == 1, false) results in "Check failed: false != false (0==1=false, false=false) ".
129#define CHECK_EQ(x, y) CHECK_OP(x, y, ==)
130#define CHECK_NE(x, y) CHECK_OP(x, y, !=)
131#define CHECK_LE(x, y) CHECK_OP(x, y, <=)
132#define CHECK_LT(x, y) CHECK_OP(x, y, <)
133#define CHECK_GE(x, y) CHECK_OP(x, y, >=)
134#define CHECK_GT(x, y) CHECK_OP(x, y, >)
135
136// Helper for CHECK_STRxx(s1,s2) macros.
137#define CHECK_STROP(s1, s2, sense) \
138  if (UNLIKELY((strcmp(s1, s2) == 0) != sense)) \
139    LOG(::art::FATAL) << "Check failed: " \
140        << "\"" << s1 << "\"" \
141        << (sense ? " == " : " != ") \
142        << "\"" << s2 << "\""
143
144// Check for string (const char*) equality between s1 and s2, LOG(FATAL) if not.
145#define CHECK_STREQ(s1, s2) CHECK_STROP(s1, s2, true)
146#define CHECK_STRNE(s1, s2) CHECK_STROP(s1, s2, false)
147
148// Perform the pthread function call(args), LOG(FATAL) on error.
149#define CHECK_PTHREAD_CALL(call, args, what) \
150  do { \
151    int rc = call args; \
152    if (rc != 0) { \
153      errno = rc; \
154      PLOG(::art::FATAL) << # call << " failed for " << what; \
155    } \
156  } while (false)
157
158// CHECK that can be used in a constexpr function. For example,
159//    constexpr int half(int n) {
160//      return
161//          DCHECK_CONSTEXPR(n >= 0, , 0)
162//          CHECK_CONSTEXPR((n & 1) == 0), << "Extra debugging output: n = " << n, 0)
163//          n / 2;
164//    }
165#define CHECK_CONSTEXPR(x, out, dummy) \
166  (UNLIKELY(!(x))) ? (LOG(::art::FATAL) << "Check failed: " << #x out, dummy) :
167
168
169// DCHECKs are debug variants of CHECKs only enabled in debug builds. Generally CHECK should be
170// used unless profiling identifies a CHECK as being in performance critical code.
171#if defined(NDEBUG)
172static constexpr bool kEnableDChecks = false;
173#else
174static constexpr bool kEnableDChecks = true;
175#endif
176
177#define DCHECK(x) if (::art::kEnableDChecks) CHECK(x)
178#define DCHECK_EQ(x, y) if (::art::kEnableDChecks) CHECK_EQ(x, y)
179#define DCHECK_NE(x, y) if (::art::kEnableDChecks) CHECK_NE(x, y)
180#define DCHECK_LE(x, y) if (::art::kEnableDChecks) CHECK_LE(x, y)
181#define DCHECK_LT(x, y) if (::art::kEnableDChecks) CHECK_LT(x, y)
182#define DCHECK_GE(x, y) if (::art::kEnableDChecks) CHECK_GE(x, y)
183#define DCHECK_GT(x, y) if (::art::kEnableDChecks) CHECK_GT(x, y)
184#define DCHECK_STREQ(s1, s2) if (::art::kEnableDChecks) CHECK_STREQ(s1, s2)
185#define DCHECK_STRNE(s1, s2) if (::art::kEnableDChecks) CHECK_STRNE(s1, s2)
186#if defined(NDEBUG)
187#define DCHECK_CONSTEXPR(x, out, dummy)
188#else
189#define DCHECK_CONSTEXPR(x, out, dummy) CHECK_CONSTEXPR(x, out, dummy)
190#endif
191
192// Temporary class created to evaluate the LHS and RHS, used with MakeEagerEvaluator to infer the
193// types of LHS and RHS.
194template <typename LHS, typename RHS>
195struct EagerEvaluator {
196  EagerEvaluator(LHS l, RHS r) : lhs(l), rhs(r) { }
197  LHS lhs;
198  RHS rhs;
199};
200
201// Helper function for CHECK_xx.
202template <typename LHS, typename RHS>
203static inline EagerEvaluator<LHS, RHS> MakeEagerEvaluator(LHS lhs, RHS rhs) {
204  return EagerEvaluator<LHS, RHS>(lhs, rhs);
205}
206
207// Explicitly instantiate EagerEvalue for pointers so that char*s aren't treated as strings. To
208// compare strings use CHECK_STREQ and CHECK_STRNE. We rely on signed/unsigned warnings to
209// protect you against combinations not explicitly listed below.
210#define EAGER_PTR_EVALUATOR(T1, T2) \
211  template <> struct EagerEvaluator<T1, T2> { \
212    EagerEvaluator(T1 l, T2 r) \
213        : lhs(reinterpret_cast<const void*>(l)), \
214          rhs(reinterpret_cast<const void*>(r)) { } \
215    const void* lhs; \
216    const void* rhs; \
217  }
218EAGER_PTR_EVALUATOR(const char*, const char*);
219EAGER_PTR_EVALUATOR(const char*, char*);
220EAGER_PTR_EVALUATOR(char*, const char*);
221EAGER_PTR_EVALUATOR(char*, char*);
222EAGER_PTR_EVALUATOR(const unsigned char*, const unsigned char*);
223EAGER_PTR_EVALUATOR(const unsigned char*, unsigned char*);
224EAGER_PTR_EVALUATOR(unsigned char*, const unsigned char*);
225EAGER_PTR_EVALUATOR(unsigned char*, unsigned char*);
226EAGER_PTR_EVALUATOR(const signed char*, const signed char*);
227EAGER_PTR_EVALUATOR(const signed char*, signed char*);
228EAGER_PTR_EVALUATOR(signed char*, const signed char*);
229EAGER_PTR_EVALUATOR(signed char*, signed char*);
230
231// Data for the log message, not stored in LogMessage to avoid increasing the stack size.
232class LogMessageData;
233
234// A LogMessage is a temporarily scoped object used by LOG and the unlikely part of a CHECK. The
235// destructor will abort if the severity is FATAL.
236class LogMessage {
237 public:
238  LogMessage(const char* file, unsigned int line, LogSeverity severity, int error);
239
240  ~LogMessage();  // TODO: enable LOCKS_EXCLUDED(Locks::logging_lock_).
241
242  // Returns the stream associated with the message, the LogMessage performs output when it goes
243  // out of scope.
244  std::ostream& stream();
245
246  // The routine that performs the actual logging.
247  static void LogLine(const char* file, unsigned int line, LogSeverity severity, const char* msg);
248
249  // A variant of the above for use with little stack.
250  static void LogLineLowStack(const char* file, unsigned int line, LogSeverity severity,
251                              const char* msg);
252
253 private:
254  const std::unique_ptr<LogMessageData> data_;
255
256  DISALLOW_COPY_AND_ASSIGN(LogMessage);
257};
258
259// Allows to temporarily change the minimum severity level for logging.
260class ScopedLogSeverity {
261 public:
262  explicit ScopedLogSeverity(LogSeverity level);
263  ~ScopedLogSeverity();
264
265 private:
266  LogSeverity old_;
267};
268
269}  // namespace art
270
271#endif  // ART_RUNTIME_BASE_LOGGING_H_
272