diff options
Diffstat (limited to 'indra/llcommon/llerror.h')
| -rw-r--r-- | indra/llcommon/llerror.h | 87 |
1 files changed, 72 insertions, 15 deletions
diff --git a/indra/llcommon/llerror.h b/indra/llcommon/llerror.h index 3beef65723..7cbe4334b3 100644 --- a/indra/llcommon/llerror.h +++ b/indra/llcommon/llerror.h @@ -174,7 +174,8 @@ namespace LLError // not really a level // used to indicate that no messages should be logged }; - + // If you change ELevel, please update llvlog() macro below. + /* Macro support The classes CallSite and Log are used by the logging macros below. They are not intended for general use. @@ -305,24 +306,38 @@ typedef LLError::NoClassInfo _LL_CLASS_TO_LOG; ///////////////////////////////// // Error Logging Macros -// See top of file for common usage. +// See top of file for common usage. ///////////////////////////////// -// this macro uses a one-shot do statement to avoid parsing errors when writing control flow statements -// without braces: -// if (condition) LL_INFOS() << "True" << LL_ENDL; else LL_INFOS()() << "False" << LL_ENDL - -#define lllog(level, once, ...) \ - do { \ - const char* tags[] = {"", ##__VA_ARGS__}; \ - ::size_t tag_count = LL_ARRAY_SIZE(tags) - 1; \ - static LLError::CallSite _site( \ - level, __FILE__, __LINE__, typeid(_LL_CLASS_TO_LOG), __FUNCTION__, once, &tags[1], tag_count);\ - if (LL_UNLIKELY(_site.shouldLog())) \ - { \ - std::ostringstream* _out = LLError::Log::out(); \ +// Instead of using LL_DEBUGS(), LL_INFOS() et al., it may be tempting to +// directly code the lllog() macro so you can pass in the LLError::ELevel as a +// variable. DON'T DO IT! The reason is that the first time control passes +// through lllog(), it initializes a local static LLError::CallSite with that +// *first* ELevel value. All subsequent visits will decide whether or not to +// emit output based on the *first* ELevel value bound into that static +// CallSite instance. Use LL_VLOGS() instead. lllog() assumes its ELevel +// argument never varies. + +// this macro uses a one-shot do statement to avoid parsing errors when +// writing control flow statements without braces: +// if (condition) LL_INFOS() << "True" << LL_ENDL; else LL_INFOS()() << "False" << LL_ENDL; + +#define lllog(level, once, ...) \ + do { \ + const char* tags[] = {"", ##__VA_ARGS__}; \ + static LLError::CallSite _site(lllog_site_args_(level, once, tags)); \ + lllog_test_() + +#define lllog_test_() \ + if (LL_UNLIKELY(_site.shouldLog())) \ + { \ + std::ostringstream* _out = LLError::Log::out(); \ (*_out) +#define lllog_site_args_(level, once, tags) \ + level, __FILE__, __LINE__, typeid(_LL_CLASS_TO_LOG), \ + __FUNCTION__, once, &tags[1], LL_ARRAY_SIZE(tags)-1 + //Use this construct if you need to do computation in the middle of a //message: // @@ -363,4 +378,46 @@ typedef LLError::NoClassInfo _LL_CLASS_TO_LOG; #define LL_INFOS_ONCE(...) lllog(LLError::LEVEL_INFO, true, ##__VA_ARGS__) #define LL_WARNS_ONCE(...) lllog(LLError::LEVEL_WARN, true, ##__VA_ARGS__) +// Use this if you need to pass LLError::ELevel as a variable. +#define LL_VLOGS(level, ...) llvlog(level, false, ##__VA_ARGS__) +#define LL_VLOGS_ONCE(level, ...) llvlog(level, true, ##__VA_ARGS__) + +// The problem with using lllog() with a variable level is that the first time +// through, it initializes a static CallSite instance with whatever level you +// pass. That first level is bound into the CallSite; the level parameter is +// never again examined. One approach to variable level would be to +// dynamically construct a CallSite instance every call -- which could get +// expensive, depending on context. So instead, initialize a static CallSite +// for each level value we support, then dynamically select the CallSite +// instance for the passed level value. +// Compare implementation to lllog() above. +#define llvlog(level, once, ...) \ + do { \ + const char* tags[] = {"", ##__VA_ARGS__}; \ + /* Need a static CallSite instance per expected ELevel value. */ \ + /* Since we intend to index this array with the ELevel, */ \ + /* _sites[0] should be ELevel(0), and so on -- avoid using */ \ + /* ELevel symbolic names when initializing -- except for */ \ + /* the last entry, which handles anything beyond the end. */ \ + /* (Commented ELevel value names are from 2016-09-01.) */ \ + /* Passing an ELevel past the end of this array is itself */ \ + /* a fatal error, so ensure the last is LEVEL_ERROR. */ \ + static LLError::CallSite _sites[] = \ + { \ + /* LEVEL_DEBUG */ \ + LLError::CallSite(lllog_site_args_(LLError::ELevel(0), once, tags)), \ + /* LEVEL_INFO */ \ + LLError::CallSite(lllog_site_args_(LLError::ELevel(1), once, tags)), \ + /* LEVEL_WARN */ \ + LLError::CallSite(lllog_site_args_(LLError::ELevel(2), once, tags)), \ + /* LEVEL_ERROR */ \ + LLError::CallSite(lllog_site_args_(LLError::LEVEL_ERROR, once, tags)) \ + }; \ + /* Clamp the passed 'level' to at most last entry */ \ + std::size_t which((std::size_t(level) >= LL_ARRAY_SIZE(_sites)) ? \ + (LL_ARRAY_SIZE(_sites) - 1) : std::size_t(level)); \ + /* selected CallSite *must* be named _site for LL_ENDL */ \ + LLError::CallSite& _site(_sites[which]); \ + lllog_test_() + #endif // LL_LLERROR_H |