src/logging/log.h

   1 /*
   2  * This is zf_log.h, modified with Babeltrace prefixes.
   3  * See <https://github.com/wonder-mice/zf_log/>.
   4  * See logging/LICENSE in the Babeltrace source tree.
   5  */
   6
   7 #pragma once
   8
   9 #ifndef BABELTRACE_LOGGING_INTERNAL_H
  10 #define BABELTRACE_LOGGING_INTERNAL_H
  11
  12 #include <errno.h>
  13 #include <stdlib.h>
  14 #include <stdio.h>
  15 #include <string.h>
  16 #include <babeltrace2/logging.h>
  17 #include "common/macros.h"
  18 #include "common/assert.h"
  19
  20 /* To detect incompatible changes you can define BT_LOG_VERSION_REQUIRED to be
  21  * the current value of BT_LOG_VERSION before including this file (or via
  22  * compiler command line):
  23  *
  24  *   #define BT_LOG_VERSION_REQUIRED 4
  25  *   #include "logging.h"
  26  *
  27  * Compilation will fail when included file has different version.
  28  */
  29 #define BT_LOG_VERSION 4
  30 #if defined(BT_LOG_VERSION_REQUIRED)
  31         #if BT_LOG_VERSION_REQUIRED != BT_LOG_VERSION
  32                 #error different bt_log version required
  33         #endif
  34 #endif
  35
  36 /* Log level guideline:
  37  * - BT_LOG_FATAL - happened something impossible and absolutely unexpected.
  38  *   Process can't continue and must be terminated.
  39  *   Example: division by zero, unexpected modifications from other thread.
  40  * - BT_LOG_ERROR - happened something possible, but highly unexpected. The
  41  *   process is able to recover and continue execution.
  42  *   Example: out of memory (could also be FATAL if not handled properly).
  43  * - BT_LOG_WARN - happened something that *usually* should not happen and
  44  *   significantly changes application behavior for some period of time.
  45  *   Example: configuration file not found, auth error.
  46  * - BT_LOG_INFO - happened significant life cycle event or major state
  47  *   transition.
  48  *   Example: app started, user logged in.
  49  * - BT_LOG_DEBUG - minimal set of events that could help to reconstruct the
  50  *   execution path. Usually disabled in release builds.
  51  * - BT_LOG_VERBOSE - all other events. Usually disabled in release builds.
  52  *
  53  * *Ideally*, log file of debugged, well tested, production ready application
  54  * should be empty or very small. Choosing a right log level is as important as
  55  * providing short and self descriptive log message.
  56  */
  57 #define BT_LOG_VERBOSE BT_LOGGING_LEVEL_VERBOSE
  58 #define BT_LOG_DEBUG   BT_LOGGING_LEVEL_DEBUG
  59 #define BT_LOG_INFO    BT_LOGGING_LEVEL_INFO
  60 #define BT_LOG_WARN    BT_LOGGING_LEVEL_WARN
  61 #define BT_LOG_ERROR   BT_LOGGING_LEVEL_ERROR
  62 #define BT_LOG_FATAL   BT_LOGGING_LEVEL_FATAL
  63 #define BT_LOG_NONE    BT_LOGGING_LEVEL_NONE
  64
  65 /* "Current" log level is a compile time check and has no runtime overhead. Log
  66  * level that is below current log level it said to be "disabled". Otherwise,
  67  * it's "enabled". Log messages that are disabled has no runtime overhead - they
  68  * are converted to no-op by preprocessor and then eliminated by compiler.
  69  * Current log level is configured per compilation module (.c/.cpp/.m file) by
  70  * defining BT_LOG_DEF_LEVEL or BT_LOG_LEVEL. BT_LOG_LEVEL has higer priority
  71  * and when defined overrides value provided by BT_LOG_DEF_LEVEL.
  72  *
  73  * Common practice is to define default current log level with BT_LOG_DEF_LEVEL
  74  * in build script (e.g. Makefile, CMakeLists.txt, gyp, etc.) for the entire
  75  * project or target:
  76  *
  77  *   CC_ARGS := -DBT_LOG_DEF_LEVEL=BT_LOG_INFO
  78  *
  79  * And when necessary to override it with BT_LOG_LEVEL in .c/.cpp/.m files
  80  * before including bt_log.h:
  81  *
  82  *   #define BT_LOG_LEVEL BT_LOG_VERBOSE
  83  *   #include "logging.h"
  84  *
  85  * If both BT_LOG_DEF_LEVEL and BT_LOG_LEVEL are undefined, then
  86  * BT_LOG_INFO will be used for release builds (BT_DEBUG_MODE is NOT
  87  * defined) and BT_LOG_DEBUG otherwise (BT_DEBUG_MODE is defined).
  88  */
  89 #if defined(BT_LOG_LEVEL)
  90         #define _BT_LOG_LEVEL BT_LOG_LEVEL
  91 #elif defined(BT_LOG_DEF_LEVEL)
  92         #define _BT_LOG_LEVEL BT_LOG_DEF_LEVEL
  93 #else
  94         #ifdef BT_DEBUG_MODE
  95                 #define _BT_LOG_LEVEL BT_LOG_DEBUG
  96         #else
  97                 #define _BT_LOG_LEVEL BT_LOG_INFO
  98         #endif
  99 #endif
 100
 101 /* "Output" log level is a runtime check. When log level is below output log
 102  * level it said to be "turned off" (or just "off" for short). Otherwise it's
 103  * "turned on" (or just "on"). Log levels that were "disabled" (see
 104  * BT_LOG_LEVEL and BT_LOG_DEF_LEVEL) can't be "turned on", but "enabled" log
 105  * levels could be "turned off". Only messages with log level which is
 106  * "turned on" will reach output facility. All other messages will be ignored
 107  * (and their arguments will not be evaluated). Output log level is a global
 108  * property and configured per process using bt_log_set_output_level() function
 109  * which can be called at any time.
 110  *
 111  * Though in some cases it could be useful to configure output log level per
 112  * compilation module or per library. There are two ways to achieve that:
 113  * - Define BT_LOG_OUTPUT_LEVEL to expresion that evaluates to desired output
 114  *   log level.
 115  * - Copy bt_log.h and bt_log.c files into your library and build it with
 116  *   BT_LOG_LIBRARY_PREFIX defined to library specific prefix. See
 117  *   BT_LOG_LIBRARY_PREFIX for more details.
 118  *
 119  * When defined, BT_LOG_OUTPUT_LEVEL must evaluate to integral value that
 120  * corresponds to desired output log level. Use it only when compilation module
 121  * is required to have output log level which is different from global output
 122  * log level set by bt_log_set_output_level() function. For other cases,
 123  * consider defining BT_LOG_LEVEL or using bt_log_set_output_level() function.
 124  *
 125  * Example:
 126  *
 127  *   #define BT_LOG_OUTPUT_LEVEL g_module_log_level
 128  *   #include "logging.h"
 129  *   static int g_module_log_level = BT_LOG_INFO;
 130  *   static void foo() {
 131  *       BT_LOGI("Will check g_module_log_level for output log level");
 132  *   }
 133  *   void debug_log(bool on) {
 134  *       g_module_log_level = on? BT_LOG_DEBUG: BT_LOG_INFO;
 135  *   }
 136  *
 137  * Note on performance. This expression will be evaluated each time message is
 138  * logged (except when message log level is "disabled" - see BT_LOG_LEVEL for
 139  * details). Keep this expression as simple as possible, otherwise it will not
 140  * only add runtime overhead, but also will increase size of call site (which
 141  * will result in larger executable). The prefered way is to use integer
 142  * variable (as in example above). If structure must be used, log_level field
 143  * must be the first field in this structure:
 144  *
 145  *   #define BT_LOG_OUTPUT_LEVEL (g_config.log_level)
 146  *   #include "logging.h"
 147  *   struct config {
 148  *       int log_level;
 149  *       unsigned other_field;
 150  *       [...]
 151  *   };
 152  *   static config g_config = {BT_LOG_INFO, 0, ...};
 153  *
 154  * This allows compiler to generate more compact load instruction (no need to
 155  * specify offset since it's zero). Calling a function to get output log level
 156  * is generaly a bad idea, since it will increase call site size and runtime
 157  * overhead even further.
 158  */
 159 #if defined(BT_LOG_OUTPUT_LEVEL)
 160         #define _BT_LOG_OUTPUT_LEVEL BT_LOG_OUTPUT_LEVEL
 161 #else
 162         /*
 163          * We disallow this to make sure Babeltrace modules always
 164          * have their own local log level.
 165          */
 166         #error No log level symbol specified: please define BT_LOG_OUTPUT_LEVEL before including this header.
 167 #endif
 168
 169 /* "Tag" is a compound string that could be associated with a log message. It
 170  * consists of tag prefix and tag (both are optional).
 171  *
 172  * Tag prefix is a global property and configured per process using
 173  * bt_log_set_tag_prefix() function. Tag prefix identifies context in which
 174  * component or module is running (e.g. process name). For example, the same
 175  * library could be used in both client and server processes that work on the
 176  * same machine. Tag prefix could be used to easily distinguish between them.
 177  * For more details about tag prefix see bt_log_set_tag_prefix() function. Tag
 178  * prefix
 179  *
 180  * Tag identifies component or module. It is configured per compilation module
 181  * (.c/.cpp/.m file) by defining BT_LOG_TAG or BT_LOG_DEF_TAG. BT_LOG_TAG has
 182  * higer priority and when defined overrides value provided by BT_LOG_DEF_TAG.
 183  * When defined, value must evaluate to (const char *), so for strings double
 184  * quotes must be used.
 185  *
 186  * Default tag could be defined with BT_LOG_DEF_TAG in build script (e.g.
 187  * Makefile, CMakeLists.txt, gyp, etc.) for the entire project or target:
 188  *
 189  *   CC_ARGS := -DBT_LOG_DEF_TAG=\"MISC\"
 190  *
 191  * And when necessary could be overriden with BT_LOG_TAG in .c/.cpp/.m files
 192  * before including bt_log.h:
 193  *
 194  *   #define BT_LOG_TAG "MAIN"
 195  *   #include "logging.h"
 196  *
 197  * If both BT_LOG_DEF_TAG and BT_LOG_TAG are undefined no tag will be added to
 198  * the log message (tag prefix still could be added though).
 199  *
 200  * Output example:
 201  *
 202  *   04-29 22:43:20.244 40059  1299 I hello.MAIN Number of arguments: 1
 203  *                                    |     |
 204  *                                    |     +- tag (e.g. module)
 205  *                                    +- tag prefix (e.g. process name)
 206  */
 207 #if defined(BT_LOG_TAG)
 208         #define _BT_LOG_TAG BT_LOG_TAG
 209 #elif defined(BT_LOG_DEF_TAG)
 210         #define _BT_LOG_TAG BT_LOG_DEF_TAG
 211 #else
 212         #define _BT_LOG_TAG 0
 213 #endif
 214
 215 /* Source location is part of a log line that describes location (function or
 216  * method name, file name and line number, e.g. "runloop@main.cpp:68") of a
 217  * log statement that produced it.
 218  * Source location formats are:
 219  * - BT_LOG_SRCLOC_NONE - don't add source location to log line.
 220  * - BT_LOG_SRCLOC_SHORT - add source location in short form (file and line
 221  *   number, e.g. "@main.cpp:68").
 222  * - BT_LOG_SRCLOC_LONG - add source location in long form (function or method
 223  *   name, file and line number, e.g. "runloop@main.cpp:68").
 224  */
 225 #define BT_LOG_SRCLOC_NONE  0
 226 #define BT_LOG_SRCLOC_SHORT 1
 227 #define BT_LOG_SRCLOC_LONG  2
 228
 229 /* Source location format is configured per compilation module (.c/.cpp/.m
 230  * file) by defining BT_LOG_DEF_SRCLOC or BT_LOG_SRCLOC. BT_LOG_SRCLOC has
 231  * higer priority and when defined overrides value provided by
 232  * BT_LOG_DEF_SRCLOC.
 233  *
 234  * Common practice is to define default format with BT_LOG_DEF_SRCLOC in
 235  * build script (e.g. Makefile, CMakeLists.txt, gyp, etc.) for the entire
 236  * project or target:
 237  *
 238  *   CC_ARGS := -DBT_LOG_DEF_SRCLOC=BT_LOG_SRCLOC_LONG
 239  *
 240  * And when necessary to override it with BT_LOG_SRCLOC in .c/.cpp/.m files
 241  * before including bt_log.h:
 242  *
 243  *   #define BT_LOG_SRCLOC BT_LOG_SRCLOC_NONE
 244  *   #include "logging.h"
 245  *
 246  * If both BT_LOG_DEF_SRCLOC and BT_LOG_SRCLOC are undefined, then
 247  * BT_LOG_SRCLOC_NONE will be used for release builds (BT_DEBUG_MODE is
 248  * NOT defined) and BT_LOG_SRCLOC_LONG otherwise (BT_DEBUG_MODE is
 249  * defined).
 250  */
 251 #if defined(BT_LOG_SRCLOC)
 252         #define _BT_LOG_SRCLOC BT_LOG_SRCLOC
 253 #elif defined(BT_LOG_DEF_SRCLOC)
 254         #define _BT_LOG_SRCLOC BT_LOG_DEF_SRCLOC
 255 #else
 256         #ifdef BT_DEBUG_MODE
 257                 #define _BT_LOG_SRCLOC BT_LOG_SRCLOC_LONG
 258         #else
 259                 #define _BT_LOG_SRCLOC BT_LOG_SRCLOC_NONE
 260         #endif
 261 #endif
 262 #if BT_LOG_SRCLOC_LONG == _BT_LOG_SRCLOC
 263         #define _BT_LOG_SRCLOC_FUNCTION _BT_LOG_FUNCTION
 264 #else
 265         #define _BT_LOG_SRCLOC_FUNCTION 0
 266 #endif
 267
 268 /* Censoring provides conditional logging of secret information, also known as
 269  * Personally Identifiable Information (PII) or Sensitive Personal Information
 270  * (SPI). Censoring can be either enabled (BT_LOG_CENSORED) or disabled
 271  * (BT_LOG_UNCENSORED). When censoring is enabled, log statements marked as
 272  * "secrets" will be ignored and will have zero overhead (arguments also will
 273  * not be evaluated).
 274  */
 275 #define BT_LOG_CENSORED   1
 276 #define BT_LOG_UNCENSORED 0
 277
 278 /* Censoring is configured per compilation module (.c/.cpp/.m file) by defining
 279  * BT_LOG_DEF_CENSORING or BT_LOG_CENSORING. BT_LOG_CENSORING has higer priority
 280  * and when defined overrides value provided by BT_LOG_DEF_CENSORING.
 281  *
 282  * Common practice is to define default censoring with BT_LOG_DEF_CENSORING in
 283  * build script (e.g. Makefile, CMakeLists.txt, gyp, etc.) for the entire
 284  * project or target:
 285  *
 286  *   CC_ARGS := -DBT_LOG_DEF_CENSORING=BT_LOG_CENSORED
 287  *
 288  * And when necessary to override it with BT_LOG_CENSORING in .c/.cpp/.m files
 289  * before including bt_log.h (consider doing it only for debug purposes and be
 290  * very careful not to push such temporary changes to source control):
 291  *
 292  *   #define BT_LOG_CENSORING BT_LOG_UNCENSORED
 293  *   #include "logging.h"
 294  *
 295  * If both BT_LOG_DEF_CENSORING and BT_LOG_CENSORING are undefined, then
 296  * BT_LOG_CENSORED will be used for release builds (BT_DEBUG_MODE is NOT
 297  * defined) and BT_LOG_UNCENSORED otherwise (BT_DEBUG_MODE is defined).
 298  */
 299 #if defined(BT_LOG_CENSORING)
 300         #define _BT_LOG_CENSORING BT_LOG_CENSORING
 301 #elif defined(BT_LOG_DEF_CENSORING)
 302         #define _BT_LOG_CENSORING BT_LOG_DEF_CENSORING
 303 #else
 304         #ifdef BT_DEBUG_MODE
 305                 #define _BT_LOG_CENSORING BT_LOG_UNCENSORED
 306         #else
 307                 #define _BT_LOG_CENSORING BT_LOG_CENSORED
 308         #endif
 309 #endif
 310
 311 /* Check censoring at compile time. Evaluates to true when censoring is disabled
 312  * (i.e. when secrets will be logged). For example:
 313  *
 314  *   #if BT_LOG_SECRETS
 315  *       char ssn[16];
 316  *       getSocialSecurityNumber(ssn);
 317  *       BT_LOGI("Customer ssn: %s", ssn);
 318  *   #endif
 319  *
 320  * See BT_LOG_SECRET() macro for a more convenient way of guarding single log
 321  * statement.
 322  */
 323 #define BT_LOG_SECRETS (BT_LOG_UNCENSORED == _BT_LOG_CENSORING)
 324
 325 /* Static (compile-time) initialization support allows to configure logging
 326  * before entering main() function. This mostly useful in C++ where functions
 327  * and methods could be called during initialization of global objects. Those
 328  * functions and methods could record log messages too and for that reason
 329  * static initialization of logging configuration is customizable.
 330  *
 331  * Macros below allow to specify values to use for initial configuration:
 332  * - BT_LOG_EXTERN_TAG_PREFIX - tag prefix (default: none)
 333  * - BT_LOG_EXTERN_GLOBAL_FORMAT - global format options (default: see
 334  *   BT_LOG_MEM_WIDTH in bt_log.c)
 335  * - BT_LOG_EXTERN_GLOBAL_OUTPUT - global output facility (default: stderr or
 336  *   platform specific, see BT_LOG_USE_XXX macros in bt_log.c)
 337  * - BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL - global output log level (default: 0 -
 338  *   all levals are "turned on")
 339  *
 340  * For example, in log_config.c:
 341  *
 342  *   #include "logging.h"
 343  *   BT_LOG_DEFINE_TAG_PREFIX = "MyApp";
 344  *   BT_LOG_DEFINE_GLOBAL_FORMAT = {CUSTOM_MEM_WIDTH};
 345  *   BT_LOG_DEFINE_GLOBAL_OUTPUT = {BT_LOG_PUT_STD, custom_output_callback, 0};
 346  *   BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL = BT_LOG_INFO;
 347  *
 348  * However, to use any of those macros bt_log library must be compiled with
 349  * following macros defined:
 350  * - to use BT_LOG_DEFINE_TAG_PREFIX define BT_LOG_EXTERN_TAG_PREFIX
 351  * - to use BT_LOG_DEFINE_GLOBAL_FORMAT define BT_LOG_EXTERN_GLOBAL_FORMAT
 352  * - to use BT_LOG_DEFINE_GLOBAL_OUTPUT define BT_LOG_EXTERN_GLOBAL_OUTPUT
 353  * - to use BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL define
 354  *   BT_LOG_EXTERN_GLOBAL_OUTPUT_LEVEL
 355  *
 356  * When bt_log library compiled with one of BT_LOG_EXTERN_XXX macros defined,
 357  * corresponding BT_LOG_DEFINE_XXX macro MUST be used exactly once somewhere.
 358  * Otherwise build will fail with link error (undefined symbol).
 359  */
 360 #define BT_LOG_DEFINE_TAG_PREFIX BT_HIDDEN const char *_bt_log_tag_prefix
 361 #define BT_LOG_DEFINE_GLOBAL_FORMAT BT_HIDDEN bt_log_format _bt_log_global_format
 362 #define BT_LOG_DEFINE_GLOBAL_OUTPUT BT_HIDDEN bt_log_output _bt_log_global_output
 363 #define BT_LOG_DEFINE_GLOBAL_OUTPUT_LEVEL BT_HIDDEN int _bt_log_global_output_lvl
 364
 365 /* Pointer to global format options. Direct modification is not allowed. Use
 366  * bt_log_set_mem_width() instead. Could be used to initialize bt_log_spec
 367  * structure:
 368  *
 369  *   const bt_log_output g_output = {BT_LOG_PUT_STD, output_callback, 0};
 370  *   const bt_log_spec g_spec = {BT_LOG_GLOBAL_FORMAT, &g_output};
 371  *   BT_LOGI_AUX(&g_spec, "Hello");
 372  */
 373 #define BT_LOG_GLOBAL_FORMAT ((const bt_log_format *)&_bt_log_global_format)
 374
 375 /* Pointer to global output variable. Direct modification is not allowed. Use
 376  * bt_log_set_output_v() or bt_log_set_output_p() instead. Could be used to
 377  * initialize bt_log_spec structure:
 378  *
 379  *   const bt_log_format g_format = {40};
 380  *   const bt_log_spec g_spec = {g_format, BT_LOG_GLOBAL_OUTPUT};
 381  *   BT_LOGI_AUX(&g_spec, "Hello");
 382  */
 383 #define BT_LOG_GLOBAL_OUTPUT ((const bt_log_output *)&_bt_log_global_output)
 384
 385 /* When defined, all library symbols produced by linker will be prefixed with
 386  * provided value. That allows to use bt_log library privately in another
 387  * libraries without exposing bt_log symbols in their original form (to avoid
 388  * possible conflicts with other libraries / components that also could use
 389  * bt_log for logging). Value must be without quotes, for example:
 390  *
 391  *   CC_ARGS := -DBT_LOG_LIBRARY_PREFIX=my_lib_
 392  *
 393  * Note, that in this mode BT_LOG_LIBRARY_PREFIX must be defined when building
 394  * bt_log library AND it also must be defined to the same value when building
 395  * a library that uses it. For example, consider fictional KittyHttp library
 396  * that wants to use bt_log for logging. First approach that could be taken is
 397  * to add bt_log.h and bt_log.c to the KittyHttp's source code tree directly.
 398  * In that case it will be enough just to define BT_LOG_LIBRARY_PREFIX in
 399  * KittyHttp's build script:
 400  *
 401  *   // KittyHttp/CMakeLists.txt
 402  *   target_compile_definitions(KittyHttp PRIVATE
 403  *                              "BT_LOG_LIBRARY_PREFIX=KittyHttp_")
 404  *
 405  * If KittyHttp doesn't want to include bt_log source code in its source tree
 406  * and wants to build bt_log as a separate library than bt_log library must be
 407  * built with BT_LOG_LIBRARY_PREFIX defined to KittyHttp_ AND KittyHttp library
 408  * itself also needs to define BT_LOG_LIBRARY_PREFIX to KittyHttp_. It can do
 409  * so either in its build script, as in example above, or by providing a
 410  * wrapper header that KittyHttp library will need to use instead of bt_log.h:
 411  *
 412  *   // KittyHttpLogging.h
 413  *   #define BT_LOG_LIBRARY_PREFIX KittyHttp_
 414  *   #include "logging.h"
 415  *
 416  * Regardless of the method chosen, the end result is that bt_log symbols will
 417  * be prefixed with "KittyHttp_", so if a user of KittyHttp (say DogeBrowser)
 418  * also uses bt_log for logging, they will not interferer with each other. Both
 419  * will have their own log level, output facility, format options etc.
 420  */
 421 #ifdef BT_LOG_LIBRARY_PREFIX
 422         #define _BT_LOG_DECOR__(prefix, name) prefix ## name
 423         #define _BT_LOG_DECOR_(prefix, name) _BT_LOG_DECOR__(prefix, name)
 424         #define _BT_LOG_DECOR(name) _BT_LOG_DECOR_(BT_LOG_LIBRARY_PREFIX, name)
 425
 426         #define bt_log_set_tag_prefix _BT_LOG_DECOR(bt_log_set_tag_prefix)
 427         #define bt_log_set_mem_width _BT_LOG_DECOR(bt_log_set_mem_width)
 428         #define bt_log_set_output_level _BT_LOG_DECOR(bt_log_set_output_level)
 429         #define bt_log_set_output_v _BT_LOG_DECOR(bt_log_set_output_v)
 430         #define bt_log_set_output_p _BT_LOG_DECOR(bt_log_set_output_p)
 431         #define bt_log_out_stderr_callback _BT_LOG_DECOR(bt_log_out_stderr_callback)
 432         #define _bt_log_tag_prefix _BT_LOG_DECOR(_bt_log_tag_prefix)
 433         #define _bt_log_global_format _BT_LOG_DECOR(_bt_log_global_format)
 434         #define _bt_log_global_output _BT_LOG_DECOR(_bt_log_global_output)
 435         #define _bt_log_global_output_lvl _BT_LOG_DECOR(_bt_log_global_output_lvl)
 436         #define _bt_log_write_d _BT_LOG_DECOR(_bt_log_write_d)
 437         #define _bt_log_write_aux_d _BT_LOG_DECOR(_bt_log_write_aux_d)
 438         #define _bt_log_write _BT_LOG_DECOR(_bt_log_write)
 439         #define _bt_log_write_aux _BT_LOG_DECOR(_bt_log_write_aux)
 440         #define _bt_log_write_mem_d _BT_LOG_DECOR(_bt_log_write_mem_d)
 441         #define _bt_log_write_mem_aux_d _BT_LOG_DECOR(_bt_log_write_mem_aux_d)
 442         #define _bt_log_write_mem _BT_LOG_DECOR(_bt_log_write_mem)
 443         #define _bt_log_write_mem_aux _BT_LOG_DECOR(_bt_log_write_mem_aux)
 444         #define _bt_log_stderr_spec _BT_LOG_DECOR(_bt_log_stderr_spec)
 445 #endif
 446
 447 #if defined(__printflike)
 448         #define _BT_LOG_PRINTFLIKE(str_index, first_to_check) \
 449                 __printflike(str_index, first_to_check)
 450 #elif defined(__MINGW_PRINTF_FORMAT)
 451         #define _BT_LOG_PRINTFLIKE(str_index, first_to_check) \
 452                 __attribute__((format(__MINGW_PRINTF_FORMAT, str_index, first_to_check)))
 453 #elif defined(__GNUC__)
 454         #define _BT_LOG_PRINTFLIKE(str_index, first_to_check) \
 455                 __attribute__((format(__printf__, str_index, first_to_check)))
 456 #else
 457         #define _BT_LOG_PRINTFLIKE(str_index, first_to_check)
 458 #endif
 459
 460 #if (defined(_WIN32) || defined(_WIN64)) && !defined(__GNUC__)
 461         #define _BT_LOG_FUNCTION __FUNCTION__
 462 #else
 463         #define _BT_LOG_FUNCTION __func__
 464 #endif
 465
 466 #if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
 467         #define _BT_LOG_INLINE __inline
 468         #define _BT_LOG_IF(cond) \
 469                 __pragma(warning(push)) \
 470                 __pragma(warning(disable:4127)) \
 471                 if(cond) \
 472                 __pragma(warning(pop))
 473         #define _BT_LOG_WHILE(cond) \
 474                 __pragma(warning(push)) \
 475                 __pragma(warning(disable:4127)) \
 476                 while(cond) \
 477                 __pragma(warning(pop))
 478 #else
 479         #define _BT_LOG_INLINE inline
 480         #define _BT_LOG_IF(cond) if(cond)
 481         #define _BT_LOG_WHILE(cond) while(cond)
 482 #endif
 483 #define _BT_LOG_NEVER _BT_LOG_IF(0)
 484 #define _BT_LOG_ONCE _BT_LOG_WHILE(0)
 485
 486 #ifdef __cplusplus
 487 extern "C" {
 488 #endif
 489
 490 /* Set tag prefix. Prefix will be separated from the tag with dot ('.').
 491  * Use 0 or empty string to disable (default). Common use is to set it to
 492  * the process (or build target) name (e.g. to separate client and server
 493  * processes). Function will NOT copy provided prefix string, but will store the
 494  * pointer. Hence specified prefix string must remain valid. See
 495  * BT_LOG_DEFINE_TAG_PREFIX for a way to set it before entering main() function.
 496  * See BT_LOG_TAG for more information about tag and tag prefix.
 497  */
 498 void bt_log_set_tag_prefix(const char *const prefix);
 499
 500 /* Set number of bytes per log line in memory (ASCII-HEX) output. Example:
 501  *
 502  *   I hello.MAIN 4c6f72656d20697073756d20646f6c6f  Lorem ipsum dolo
 503  *                |<-          w bytes         ->|  |<-  w chars ->|
 504  *
 505  * See BT_LOGF_MEM and BT_LOGF_MEM_AUX for more details.
 506  */
 507 void bt_log_set_mem_width(const unsigned w);
 508
 509 /* Set "output" log level. See BT_LOG_LEVEL and BT_LOG_OUTPUT_LEVEL for more
 510  * info about log levels.
 511  */
 512 void bt_log_set_output_level(const int lvl);
 513
 514 /* Put mask is a set of flags that define what fields will be added to each
 515  * log message. Default value is BT_LOG_PUT_STD and other flags could be used to
 516  * alter its behavior. See bt_log_set_output_v() for more details.
 517  *
 518  * Note about BT_LOG_PUT_SRC: it will be added only in debug builds
 519  * (BT_DEBUG_MODE is defined).
 520  */
 521 enum
 522 {
 523         BT_LOG_PUT_CTX = 1 << 0, /* context (time, pid, tid, log level) */
 524         BT_LOG_PUT_TAG = 1 << 1, /* tag (including tag prefix) */
 525         BT_LOG_PUT_SRC = 1 << 2, /* source location (file, line, function) */
 526         BT_LOG_PUT_MSG = 1 << 3, /* message text (formatted string) */
 527         BT_LOG_PUT_STD = 0xffff, /* everything (default) */
 528 };
 529
 530 typedef struct bt_log_message
 531 {
 532         int lvl; /* Log level of the message */
 533         const char *tag; /* Associated tag (without tag prefix) */
 534         char *buf; /* Buffer start */
 535         char *e; /* Buffer end (last position where EOL with 0 could be written) */
 536         char *p; /* Buffer content end (append position) */
 537         char *tag_b; /* Prefixed tag start */
 538         char *tag_e; /* Prefixed tag end (if != tag_b, points to msg separator) */
 539         char *msg_b; /* Message start (expanded format string) */
 540 }
 541 bt_log_message;
 542
 543 /* Type of output callback function. It will be called for each log line allowed
 544  * by both "current" and "output" log levels ("enabled" and "turned on").
 545  * Callback function is allowed to modify content of the buffers pointed by the
 546  * msg, but it's not allowed to modify any of msg fields. Buffer pointed by msg
 547  * is UTF-8 encoded (no BOM mark).
 548  */
 549 typedef void (*bt_log_output_cb)(const bt_log_message *msg, void *arg);
 550
 551 /* Format options. For more details see bt_log_set_mem_width().
 552  */
 553 typedef struct bt_log_format
 554 {
 555         unsigned mem_width; /* Bytes per line in memory (ASCII-HEX) dump */
 556 }
 557 bt_log_format;
 558
 559 /* Output facility.
 560  */
 561 typedef struct bt_log_output
 562 {
 563         unsigned mask; /* What to put into log line buffer (see BT_LOG_PUT_XXX) */
 564         void *arg; /* User provided output callback argument */
 565         bt_log_output_cb callback; /* Output callback function */
 566 }
 567 bt_log_output;
 568
 569 /* Set output callback function.
 570  *
 571  * Mask allows to control what information will be added to the log line buffer
 572  * before callback function is invoked. Default mask value is BT_LOG_PUT_STD.
 573  */
 574 void bt_log_set_output_v(const unsigned mask, void *const arg,
 575                                                  const bt_log_output_cb callback);
 576 static _BT_LOG_INLINE void bt_log_set_output_p(const bt_log_output *const output)
 577 {
 578         bt_log_set_output_v(output->mask, output->arg, output->callback);
 579 }
 580
 581 /* Used with _AUX macros and allows to override global format and output
 582  * facility. Use BT_LOG_GLOBAL_FORMAT and BT_LOG_GLOBAL_OUTPUT for values from
 583  * global configuration. Example:
 584  *
 585  *   static const bt_log_output module_output = {
 586  *       BT_LOG_PUT_STD, 0, custom_output_callback
 587  *   };
 588  *   static const bt_log_spec module_spec = {
 589  *       BT_LOG_GLOBAL_FORMAT, &module_output
 590  *   };
 591  *   BT_LOGI_AUX(&module_spec, "Position: %ix%i", x, y);
 592  *
 593  * See BT_LOGF_AUX and BT_LOGF_MEM_AUX for details.
 594  */
 595 typedef struct bt_log_spec
 596 {
 597         const bt_log_format *format;
 598         const bt_log_output *output;
 599 }
 600 bt_log_spec;
 601
 602 #ifdef __cplusplus
 603 }
 604 #endif
 605
 606 /* Execute log statement if condition is true. Example:
 607  *
 608  *   BT_LOG_IF(1 < 2, BT_LOGI("Log this"));
 609  *   BT_LOG_IF(1 > 2, BT_LOGI("Don't log this"));
 610  *
 611  * Keep in mind though, that if condition can't be evaluated at compile time,
 612  * then it will be evaluated at run time. This will increase exectuable size
 613  * and can have noticeable performance overhead. Try to limit conditions to
 614  * expressions that can be evaluated at compile time.
 615  */
 616 #define BT_LOG_IF(cond, f) do { _BT_LOG_IF((cond)) { f; } } _BT_LOG_ONCE
 617
 618 /* Mark log statement as "secret". Log statements that are marked as secrets
 619  * will NOT be executed when censoring is enabled (see BT_LOG_CENSORED).
 620  * Example:
 621  *
 622  *   BT_LOG_SECRET(BT_LOGI("Credit card: %s", credit_card));
 623  *   BT_LOG_SECRET(BT_LOGD_MEM(cipher, cipher_sz, "Cipher bytes:"));
 624  */
 625 #define BT_LOG_SECRET(f) BT_LOG_IF(BT_LOG_SECRETS, f)
 626
 627 /* Check "current" log level at compile time (ignoring "output" log level).
 628  * Evaluates to true when specified log level is enabled. For example:
 629  *
 630  *   #if BT_LOG_ENABLED_DEBUG
 631  *       const char *const g_enum_strings[] = {
 632  *           "enum_value_0", "enum_value_1", "enum_value_2"
 633  *       };
 634  *   #endif
 635  *   // ...
 636  *   #if BT_LOG_ENABLED_DEBUG
 637  *       BT_LOGD("enum value: %s", g_enum_strings[v]);
 638  *   #endif
 639  *
 640  * See BT_LOG_LEVEL for details.
 641  */
 642 #define BT_LOG_ENABLED(lvl)     ((lvl) >= _BT_LOG_LEVEL)
 643 #define BT_LOG_ENABLED_VERBOSE  BT_LOG_ENABLED(BT_LOG_VERBOSE)
 644 #define BT_LOG_ENABLED_DEBUG    BT_LOG_ENABLED(BT_LOG_DEBUG)
 645 #define BT_LOG_ENABLED_INFO     BT_LOG_ENABLED(BT_LOG_INFO)
 646 #define BT_LOG_ENABLED_WARN     BT_LOG_ENABLED(BT_LOG_WARN)
 647 #define BT_LOG_ENABLED_ERROR    BT_LOG_ENABLED(BT_LOG_ERROR)
 648 #define BT_LOG_ENABLED_FATAL    BT_LOG_ENABLED(BT_LOG_FATAL)
 649
 650 /* Check "output" log level at run time (taking into account "current" log
 651  * level as well). Evaluates to true when specified log level is turned on AND
 652  * enabled. For example:
 653  *
 654  *   if (BT_LOG_ON_DEBUG)
 655  *   {
 656  *       char hash[65];
 657  *       sha256(data_ptr, data_sz, hash);
 658  *       BT_LOGD("data: len=%u, sha256=%s", data_sz, hash);
 659  *   }
 660  *
 661  * See BT_LOG_OUTPUT_LEVEL for details.
 662  */
 663 #define BT_LOG_ON(lvl) \
 664                 (BT_LOG_ENABLED((lvl)) && (lvl) >= _BT_LOG_OUTPUT_LEVEL)
 665 #define BT_LOG_ON_VERBOSE   BT_LOG_ON(BT_LOG_VERBOSE)
 666 #define BT_LOG_ON_DEBUG     BT_LOG_ON(BT_LOG_DEBUG)
 667 #define BT_LOG_ON_INFO      BT_LOG_ON(BT_LOG_INFO)
 668 #define BT_LOG_ON_WARN      BT_LOG_ON(BT_LOG_WARN)
 669 #define BT_LOG_ON_ERROR     BT_LOG_ON(BT_LOG_ERROR)
 670 #define BT_LOG_ON_FATAL     BT_LOG_ON(BT_LOG_FATAL)
 671
 672 #ifdef __cplusplus
 673 extern "C" {
 674 #endif
 675
 676 extern const char *_bt_log_tag_prefix;
 677 extern bt_log_format _bt_log_global_format;
 678 extern bt_log_output _bt_log_global_output;
 679 extern int _bt_log_global_output_lvl;
 680 extern const bt_log_spec _bt_log_stderr_spec;
 681
 682 BT_HIDDEN
 683 void _bt_log_write_d(
 684                 const char *const func, const char *const file, const unsigned line,
 685                 const int lvl, const char *const tag,
 686                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(6, 7);
 687
 688 BT_HIDDEN
 689 void _bt_log_write_aux_d(
 690                 const char *const func, const char *const file, const unsigned line,
 691                 const bt_log_spec *const log, const int lvl, const char *const tag,
 692                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(7, 8);
 693
 694 BT_HIDDEN
 695 void _bt_log_write(
 696                 const int lvl, const char *const tag,
 697                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(3, 4);
 698
 699 BT_HIDDEN
 700 void _bt_log_write_aux(
 701                 const bt_log_spec *const log, const int lvl, const char *const tag,
 702                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(4, 5);
 703
 704 BT_HIDDEN
 705 void _bt_log_write_mem_d(
 706                 const char *const func, const char *const file, const unsigned line,
 707                 const int lvl, const char *const tag,
 708                 const void *const d, const unsigned d_sz,
 709                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(8, 9);
 710
 711 BT_HIDDEN
 712 void _bt_log_write_mem_aux_d(
 713                 const char *const func, const char *const file, const unsigned line,
 714                 const bt_log_spec *const log, const int lvl, const char *const tag,
 715                 const void *const d, const unsigned d_sz,
 716                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(9, 10);
 717
 718 BT_HIDDEN
 719 void _bt_log_write_mem(
 720                 const int lvl, const char *const tag,
 721                 const void *const d, const unsigned d_sz,
 722                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(5, 6);
 723
 724 BT_HIDDEN
 725 void _bt_log_write_mem_aux(
 726                 const bt_log_spec *const log, const int lvl, const char *const tag,
 727                 const void *const d, const unsigned d_sz,
 728                 const char *const fmt, ...) _BT_LOG_PRINTFLIKE(6, 7);
 729
 730 #ifdef __cplusplus
 731 }
 732 #endif
 733
 734 /* Message logging macros:
 735  * - BT_LOGV("format string", args, ...)
 736  * - BT_LOGD("format string", args, ...)
 737  * - BT_LOGI("format string", args, ...)
 738  * - BT_LOGW("format string", args, ...)
 739  * - BT_LOGE("format string", args, ...)
 740  * - BT_LOGF("format string", args, ...)
 741  *
 742  * Message and error string (errno) logging macros:
 743  * - BT_LOGV_ERRNO("initial message", "format string", args, ...)
 744  * - BT_LOGD_ERRNO("initial message", "format string", args, ...)
 745  * - BT_LOGI_ERRNO("initial message", "format string", args, ...)
 746  * - BT_LOGW_ERRNO("initial message", "format string", args, ...)
 747  * - BT_LOGE_ERRNO("initial message", "format string", args, ...)
 748  * - BT_LOGF_ERRNO("initial message", "format string", args, ...)
 749  *
 750  * Memory logging macros:
 751  * - BT_LOGV_MEM(data_ptr, data_sz, "format string", args, ...)
 752  * - BT_LOGD_MEM(data_ptr, data_sz, "format string", args, ...)
 753  * - BT_LOGI_MEM(data_ptr, data_sz, "format string", args, ...)
 754  * - BT_LOGW_MEM(data_ptr, data_sz, "format string", args, ...)
 755  * - BT_LOGE_MEM(data_ptr, data_sz, "format string", args, ...)
 756  * - BT_LOGF_MEM(data_ptr, data_sz, "format string", args, ...)
 757  *
 758  * Auxiliary logging macros:
 759  * - BT_LOGV_AUX(&log_instance, "format string", args, ...)
 760  * - BT_LOGD_AUX(&log_instance, "format string", args, ...)
 761  * - BT_LOGI_AUX(&log_instance, "format string", args, ...)
 762  * - BT_LOGW_AUX(&log_instance, "format string", args, ...)
 763  * - BT_LOGE_AUX(&log_instance, "format string", args, ...)
 764  * - BT_LOGF_AUX(&log_instance, "format string", args, ...)
 765  *
 766  * Auxiliary memory logging macros:
 767  * - BT_LOGV_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 768  * - BT_LOGD_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 769  * - BT_LOGI_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 770  * - BT_LOGW_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 771  * - BT_LOGE_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 772  * - BT_LOGF_MEM_AUX(&log_instance, data_ptr, data_sz, "format string", args, ...)
 773  *
 774  * Preformatted string logging macros:
 775  * - BT_LOGV_STR("preformatted string");
 776  * - BT_LOGD_STR("preformatted string");
 777  * - BT_LOGI_STR("preformatted string");
 778  * - BT_LOGW_STR("preformatted string");
 779  * - BT_LOGE_STR("preformatted string");
 780  * - BT_LOGF_STR("preformatted string");
 781  *
 782  * Explicit log level and tag macros:
 783  * - BT_LOG_WRITE(level, tag, "format string", args, ...)
 784  * - BT_LOG_WRITE_MEM(level, tag, data_ptr, data_sz, "format string", args, ...)
 785  * - BT_LOG_WRITE_AUX(&log_instance, level, tag, "format string", args, ...)
 786  * - BT_LOG_WRITE_MEM_AUX(&log_instance, level, tag, data_ptr, data_sz,
 787  *                        "format string", args, ...)
 788  *
 789  * Format string follows printf() conventions. Both data_ptr and data_sz could
 790  * be 0. Tag can be 0 as well. Most compilers will verify that type of arguments
 791  * match format specifiers in format string.
 792  *
 793  * Library assuming UTF-8 encoding for all strings (char *), including format
 794  * string itself.
 795  */
 796 #if BT_LOG_SRCLOC_NONE == _BT_LOG_SRCLOC
 797         #define BT_LOG_WRITE(lvl, tag, ...) \
 798                         do { \
 799                                 if (BT_LOG_ON(lvl)) \
 800                                         _bt_log_write(lvl, tag, __VA_ARGS__); \
 801                         } _BT_LOG_ONCE
 802         #define BT_LOG_WRITE_MEM(lvl, tag, d, d_sz, ...) \
 803                         do { \
 804                                 if (BT_LOG_ON(lvl)) \
 805                                         _bt_log_write_mem(lvl, tag, d, d_sz, __VA_ARGS__); \
 806                         } _BT_LOG_ONCE
 807         #define BT_LOG_WRITE_AUX(log, lvl, tag, ...) \
 808                         do { \
 809                                 if (BT_LOG_ON(lvl)) \
 810                                         _bt_log_write_aux(log, lvl, tag, __VA_ARGS__); \
 811                         } _BT_LOG_ONCE
 812         #define BT_LOG_WRITE_MEM_AUX(log, lvl, tag, d, d_sz, ...) \
 813                         do { \
 814                                 if (BT_LOG_ON(lvl)) \
 815                                         _bt_log_write_mem_aux(log, lvl, tag, d, d_sz, __VA_ARGS__); \
 816                         } _BT_LOG_ONCE
 817 #else
 818         #define BT_LOG_WRITE(lvl, tag, ...) \
 819                         do { \
 820                                 if (BT_LOG_ON(lvl)) \
 821                                         _bt_log_write_d(_BT_LOG_SRCLOC_FUNCTION, __FILE__, __LINE__, \
 822                                                         lvl, tag, __VA_ARGS__); \
 823                         } _BT_LOG_ONCE
 824         #define BT_LOG_WRITE_MEM(lvl, tag, d, d_sz, ...) \
 825                         do { \
 826                                 if (BT_LOG_ON(lvl)) \
 827                                         _bt_log_write_mem_d(_BT_LOG_SRCLOC_FUNCTION, __FILE__, __LINE__, \
 828                                                         lvl, tag, d, d_sz, __VA_ARGS__); \
 829                         } _BT_LOG_ONCE
 830         #define BT_LOG_WRITE_AUX(log, lvl, tag, ...) \
 831                         do { \
 832                                 if (BT_LOG_ON(lvl)) \
 833                                         _bt_log_write_aux_d(_BT_LOG_SRCLOC_FUNCTION, __FILE__, __LINE__, \
 834                                                         log, lvl, tag, __VA_ARGS__); \
 835                         } _BT_LOG_ONCE
 836         #define BT_LOG_WRITE_MEM_AUX(log, lvl, tag, d, d_sz, ...) \
 837                         do { \
 838                                 if (BT_LOG_ON(lvl)) \
 839                                         _bt_log_write_mem_aux_d(_BT_LOG_SRCLOC_FUNCTION, __FILE__, __LINE__, \
 840                                                         log, lvl, tag, d, d_sz, __VA_ARGS__); \
 841                         } _BT_LOG_ONCE
 842 #endif
 843
 844 #define BT_LOG_WRITE_ERRNO(lvl, tag, _msg, _fmt, args...) \
 845                 do { \
 846                         const char *error_str; \
 847                         error_str = g_strerror(errno); \
 848                         BT_LOG_WRITE(lvl, tag, _msg ": %s" _fmt, error_str, ## args); \
 849                 } _BT_LOG_ONCE
 850
 851 static _BT_LOG_INLINE void _bt_log_unused(const int dummy, ...) {(void)dummy;}
 852
 853 #define _BT_LOG_UNUSED(...) \
 854                 do { _BT_LOG_NEVER _bt_log_unused(0, __VA_ARGS__); } _BT_LOG_ONCE
 855
 856 #if BT_LOG_ENABLED_VERBOSE
 857         #define BT_LOGV(...) \
 858                         BT_LOG_WRITE(BT_LOG_VERBOSE, _BT_LOG_TAG, __VA_ARGS__)
 859         #define BT_LOGV_ERRNO(...) \
 860                         BT_LOG_WRITE_ERRNO(BT_LOG_VERBOSE, _BT_LOG_TAG, __VA_ARGS__)
 861         #define BT_LOGV_AUX(log, ...) \
 862                         BT_LOG_WRITE_AUX(log, BT_LOG_VERBOSE, _BT_LOG_TAG, __VA_ARGS__)
 863         #define BT_LOGV_MEM(d, d_sz, ...) \
 864                         BT_LOG_WRITE_MEM(BT_LOG_VERBOSE, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 865         #define BT_LOGV_MEM_AUX(log, d, d_sz, ...) \
 866                         BT_LOG_WRITE_MEM(log, BT_LOG_VERBOSE, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 867 #else
 868         #define BT_LOGV(...) _BT_LOG_UNUSED(__VA_ARGS__)
 869         #define BT_LOGV_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 870         #define BT_LOGV_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 871         #define BT_LOGV_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 872 #endif
 873
 874 #if BT_LOG_ENABLED_DEBUG
 875         #define BT_LOGD(...) \
 876                         BT_LOG_WRITE(BT_LOG_DEBUG, _BT_LOG_TAG, __VA_ARGS__)
 877         #define BT_LOGD_ERRNO(...) \
 878                         BT_LOG_WRITE_ERRNO(BT_LOG_DEBUG, _BT_LOG_TAG, __VA_ARGS__)
 879         #define BT_LOGD_AUX(log, ...) \
 880                         BT_LOG_WRITE_AUX(log, BT_LOG_DEBUG, _BT_LOG_TAG, __VA_ARGS__)
 881         #define BT_LOGD_MEM(d, d_sz, ...) \
 882                         BT_LOG_WRITE_MEM(BT_LOG_DEBUG, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 883         #define BT_LOGD_MEM_AUX(log, d, d_sz, ...) \
 884                         BT_LOG_WRITE_MEM_AUX(log, BT_LOG_DEBUG, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 885 #else
 886         #define BT_LOGD(...) _BT_LOG_UNUSED(__VA_ARGS__)
 887         #define BT_LOGD_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 888         #define BT_LOGD_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 889         #define BT_LOGD_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 890 #endif
 891
 892 #if BT_LOG_ENABLED_INFO
 893         #define BT_LOGI(...) \
 894                         BT_LOG_WRITE(BT_LOG_INFO, _BT_LOG_TAG, __VA_ARGS__)
 895         #define BT_LOGI_ERRNO(...) \
 896                         BT_LOG_WRITE_ERRNO(BT_LOG_INFO, _BT_LOG_TAG, __VA_ARGS__)
 897         #define BT_LOGI_AUX(log, ...) \
 898                         BT_LOG_WRITE_AUX(log, BT_LOG_INFO, _BT_LOG_TAG, __VA_ARGS__)
 899         #define BT_LOGI_MEM(d, d_sz, ...) \
 900                         BT_LOG_WRITE_MEM(BT_LOG_INFO, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 901         #define BT_LOGI_MEM_AUX(log, d, d_sz, ...) \
 902                         BT_LOG_WRITE_MEM_AUX(log, BT_LOG_INFO, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 903 #else
 904         #define BT_LOGI(...) _BT_LOG_UNUSED(__VA_ARGS__)
 905         #define BT_LOGI_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 906         #define BT_LOGI_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 907         #define BT_LOGI_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 908 #endif
 909
 910 #if BT_LOG_ENABLED_WARN
 911         #define BT_LOGW(...) \
 912                         BT_LOG_WRITE(BT_LOG_WARN, _BT_LOG_TAG, __VA_ARGS__)
 913         #define BT_LOGW_ERRNO(...) \
 914                         BT_LOG_WRITE_ERRNO(BT_LOG_WARN, _BT_LOG_TAG, __VA_ARGS__)
 915         #define BT_LOGW_AUX(log, ...) \
 916                         BT_LOG_WRITE_AUX(log, BT_LOG_WARN, _BT_LOG_TAG, __VA_ARGS__)
 917         #define BT_LOGW_MEM(d, d_sz, ...) \
 918                         BT_LOG_WRITE_MEM(BT_LOG_WARN, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 919         #define BT_LOGW_MEM_AUX(log, d, d_sz, ...) \
 920                         BT_LOG_WRITE_MEM_AUX(log, BT_LOG_WARN, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 921 #else
 922         #define BT_LOGW(...) _BT_LOG_UNUSED(__VA_ARGS__)
 923         #define BT_LOGW_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 924         #define BT_LOGW_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 925         #define BT_LOGW_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 926 #endif
 927
 928 #if BT_LOG_ENABLED_ERROR
 929         #define BT_LOGE(...) \
 930                         BT_LOG_WRITE(BT_LOG_ERROR, _BT_LOG_TAG, __VA_ARGS__)
 931         #define BT_LOGE_ERRNO(...) \
 932                         BT_LOG_WRITE_ERRNO(BT_LOG_ERROR, _BT_LOG_TAG, __VA_ARGS__)
 933         #define BT_LOGE_AUX(log, ...) \
 934                         BT_LOG_WRITE_AUX(log, BT_LOG_ERROR, _BT_LOG_TAG, __VA_ARGS__)
 935         #define BT_LOGE_MEM(d, d_sz, ...) \
 936                         BT_LOG_WRITE_MEM(BT_LOG_ERROR, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 937         #define BT_LOGE_MEM_AUX(log, d, d_sz, ...) \
 938                         BT_LOG_WRITE_MEM_AUX(log, BT_LOG_ERROR, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 939 #else
 940         #define BT_LOGE(...) _BT_LOG_UNUSED(__VA_ARGS__)
 941         #define BT_LOGE_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 942         #define BT_LOGE_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 943         #define BT_LOGE_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 944 #endif
 945
 946 #if BT_LOG_ENABLED_FATAL
 947         #define BT_LOGF(...) \
 948                         BT_LOG_WRITE(BT_LOG_FATAL, _BT_LOG_TAG, __VA_ARGS__)
 949         #define BT_LOGF_ERRNO(...) \
 950                         BT_LOG_WRITE_ERRNO(BT_LOG_FATAL, _BT_LOG_TAG, __VA_ARGS__)
 951         #define BT_LOGF_AUX(log, ...) \
 952                         BT_LOG_WRITE_AUX(log, BT_LOG_FATAL, _BT_LOG_TAG, __VA_ARGS__)
 953         #define BT_LOGF_MEM(d, d_sz, ...) \
 954                         BT_LOG_WRITE_MEM(BT_LOG_FATAL, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 955         #define BT_LOGF_MEM_AUX(log, d, d_sz, ...) \
 956                         BT_LOG_WRITE_MEM_AUX(log, BT_LOG_FATAL, _BT_LOG_TAG, d, d_sz, __VA_ARGS__)
 957 #else
 958         #define BT_LOGF(...) _BT_LOG_UNUSED(__VA_ARGS__)
 959         #define BT_LOGF_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 960         #define BT_LOGF_MEM(...) _BT_LOG_UNUSED(__VA_ARGS__)
 961         #define BT_LOGF_MEM_AUX(...) _BT_LOG_UNUSED(__VA_ARGS__)
 962 #endif
 963
 964 #define BT_LOGV_STR(s) BT_LOGV("%s", (s))
 965 #define BT_LOGD_STR(s) BT_LOGD("%s", (s))
 966 #define BT_LOGI_STR(s) BT_LOGI("%s", (s))
 967 #define BT_LOGW_STR(s) BT_LOGW("%s", (s))
 968 #define BT_LOGE_STR(s) BT_LOGE("%s", (s))
 969 #define BT_LOGF_STR(s) BT_LOGF("%s", (s))
 970
 971 #ifdef __cplusplus
 972 extern "C" {
 973 #endif
 974
 975 /* Output to standard error stream. Library uses it by default, though in few
 976  * cases it could be necessary to specify it explicitly. For example, when
 977  * bt_log library is compiled with BT_LOG_EXTERN_GLOBAL_OUTPUT, application must
 978  * define and initialize global output variable:
 979  *
 980  *   BT_LOG_DEFINE_GLOBAL_OUTPUT = {BT_LOG_OUT_STDERR};
 981  *
 982  * Another example is when using custom output, stderr could be used as a
 983  * fallback when custom output facility failed to initialize:
 984  *
 985  *   bt_log_set_output_v(BT_LOG_OUT_STDERR);
 986  */
 987 enum { BT_LOG_OUT_STDERR_MASK = BT_LOG_PUT_STD };
 988
 989 BT_HIDDEN
 990 void bt_log_out_stderr_callback(const bt_log_message *const msg, void *arg);
 991 #define BT_LOG_OUT_STDERR BT_LOG_OUT_STDERR_MASK, 0, bt_log_out_stderr_callback
 992
 993 /* Predefined spec for stderr. Uses global format options (BT_LOG_GLOBAL_FORMAT)
 994  * and BT_LOG_OUT_STDERR. Could be used to force output to stderr for a
 995  * particular message. Example:
 996  *
 997  *   f = fopen("foo.log", "w");
 998  *   if (!f)
 999  *       BT_LOGE_AUX(BT_LOG_STDERR, "Failed to open log file");
1000  */
1001 #define BT_LOG_STDERR (&_bt_log_stderr_spec)
1002
1003 /*
1004  * Returns the equivalent letter of the log level `level`.
1005  *
1006  * `level` must be a valid log level.
1007  */
1008 static inline
1009 char bt_log_get_letter_from_level(int level)
1010 {
1011         char letter;
1012
1013         switch (level) {
1014         case BT_LOG_VERBOSE:
1015                 letter = 'V';
1016                 break;
1017         case BT_LOG_DEBUG:
1018                 letter = 'D';
1019                 break;
1020         case BT_LOG_INFO:
1021                 letter = 'I';
1022                 break;
1023         case BT_LOG_WARN:
1024                 letter = 'W';
1025                 break;
1026         case BT_LOG_ERROR:
1027                 letter = 'E';
1028                 break;
1029         case BT_LOG_FATAL:
1030                 letter = 'F';
1031                 break;
1032         case BT_LOG_NONE:
1033                 letter = 'N';
1034                 break;
1035         default:
1036                 abort();
1037         }
1038
1039         return letter;
1040 }
1041
1042 /*
1043  * Returns the log level for the string `str`, or -1 if `str` is not a
1044  * valid log level string.
1045  */
1046 static inline
1047 int bt_log_get_level_from_string(const char *str)
1048 {
1049         int level = -1;
1050
1051         BT_ASSERT(str);
1052
1053         if (strcmp(str, "VERBOSE") == 0 ||
1054                         strcmp(str, "V") == 0) {
1055                 level = BT_LOG_VERBOSE;
1056         } else if (strcmp(str, "DEBUG") == 0 ||
1057                         strcmp(str, "D") == 0) {
1058                 level = BT_LOG_DEBUG;
1059         } else if (strcmp(str, "INFO") == 0 ||
1060                         strcmp(str, "I") == 0) {
1061                 level = BT_LOG_INFO;
1062         } else if (strcmp(str, "WARN") == 0 ||
1063                         strcmp(str, "WARNING") == 0 ||
1064                         strcmp(str, "W") == 0) {
1065                 level = BT_LOG_WARN;
1066         } else if (strcmp(str, "ERROR") == 0 ||
1067                         strcmp(str, "E") == 0) {
1068                 level = BT_LOG_ERROR;
1069         } else if (strcmp(str, "FATAL") == 0 ||
1070                         strcmp(str, "F") == 0) {
1071                 level = BT_LOG_FATAL;
1072         } else if (strcmp(str, "NONE") == 0 ||
1073                         strcmp(str, "N") == 0) {
1074                 level = BT_LOG_NONE;
1075         } else {
1076                 /* FIXME: Should we warn here? How? */
1077         }
1078
1079         return level;
1080 }
1081
1082 /*
1083  * Returns the log level for the letter `letter`, or -1 if `letter` is
1084  * not a valid log level string.
1085  */
1086 static inline
1087 int bt_log_get_level_from_letter(char letter)
1088 {
1089         char str[] = {letter, '\0'};
1090
1091         return bt_log_get_level_from_string(str);
1092 }
1093
1094 static inline
1095 int bt_log_get_level_from_env(const char *var)
1096 {
1097         const char *varval = getenv(var);
1098         int level = BT_LOG_NONE;
1099
1100         if (!varval) {
1101                 goto end;
1102         }
1103
1104         level = bt_log_get_level_from_string(varval);
1105         if (level < 0) {
1106                 /* FIXME: Should we warn here? How? */
1107                 level = BT_LOG_NONE;
1108         }
1109
1110 end:
1111         return level;
1112 }
1113
1114 #define BT_LOG_LEVEL_EXTERN_SYMBOL(_level_sym)                          \
1115         extern int _level_sym
1116
1117 #define BT_LOG_INIT_LOG_LEVEL(_level_sym, _env_var)                     \
1118         BT_HIDDEN int _level_sym = BT_LOG_NONE;                         \
1119         static                                                          \
1120         void __attribute__((constructor)) _bt_log_level_ctor(void)      \
1121         {                                                               \
1122                 _level_sym = bt_log_get_level_from_env(_env_var);       \
1123         }
1124
1125 #ifdef __cplusplus
1126 }
1127 #endif
1128
1129 #endif /* BABELTRACE_LOGGING_INTERNAL_H */