commit 6fc6cbd9b347ee1f82a024a04c0276bbc6e82c99 Author: David Goulet dgoulet@torproject.org Date: Thu Jan 9 12:17:49 2020 -0500
trace: Better structure lib/trace and configure options
In the next commits, we'll add more tracing options for instrumentation and specific tracer.
This rename follows a more meaningful naming standard. It also adds a catch all "HAVE_TRACING" define that indicate in the code that we have tracing enabled.
Part of #32910
Signed-off-by: David Goulet dgoulet@torproject.org --- configure.ac | 29 +++++++++++++++++++-------- src/lib/trace/debug.h | 30 ++++++++++++++++++---------- src/lib/trace/events.h | 52 +++++++++++++++++++----------------------------- src/lib/trace/include.am | 10 ++++++---- 4 files changed, 66 insertions(+), 55 deletions(-)
diff --git a/configure.ac b/configure.ac index a6df7149a..680111b10 100644 --- a/configure.ac +++ b/configure.ac @@ -256,15 +256,22 @@ AC_ARG_ENABLE(seccomp, AC_ARG_ENABLE(libscrypt, AS_HELP_STRING(--disable-libscrypt, [do not attempt to use libscrypt]))
-dnl Enable event tracing which are transformed to debug log statement. -AC_ARG_ENABLE(event-tracing-debug, - AS_HELP_STRING(--enable-event-tracing-debug, [build with event tracing to debug log])) -AM_CONDITIONAL([USE_EVENT_TRACING_DEBUG], [test "x$enable_event_tracing_debug" = "xyes"]) +dnl --- Tracing Options. ---
-if test x$enable_event_tracing_debug = xyes; then - AC_DEFINE([USE_EVENT_TRACING_DEBUG], [1], [Tracing framework to log debug]) - AC_DEFINE([TOR_EVENT_TRACING_ENABLED], [1], [Compile the event tracing instrumentation]) -fi +dnl Tracepoints event to debug logs. +AC_ARG_ENABLE(tracing-instrumentation-log-debug, + AS_HELP_STRING([--enable-tracing-instrumentation-log-debug], + [build with tracing event to debug log]), + AC_DEFINE([USE_TRACING_INSTRUMENTATION_LOG_DEBUG], [1], + [Tracepoints to log debug]), []) +AM_CONDITIONAL([USE_TRACING_INSTRUMENTATION_LOG_DEBUG], + [test "x$enable_tracing_instrumentation_log_debug" = "xyes"]) + +dnl Define that tracing is supported. +AM_COND_IF([USE_TRACING_INSTRUMENTATION_LOG_DEBUG], + AC_DEFINE([HAVE_TRACING], [1], [Compiled with tracing support])) + +dnl -- End Tracing Options. --
dnl Enable Android only features. AC_ARG_ENABLE(android, @@ -2718,6 +2725,12 @@ PPRINT_PROP_BOOL([libFuzzer support (--enable-libfuzzer)], $value) test "x$enable_oss_fuzz" = "xyes" && value=1 || value=0 PPRINT_PROP_BOOL([OSS-Fuzz support (--enable-oss-fuzz)], $value)
+AS_ECHO +PPRINT_SUBTITLE([Tracing]) + +test "x$enable_tracing_instrumentation_log_debug" = "xyes" && value=1 || value=0 +PPRINT_PROP_BOOL([Tracepoints to log_debug() (--enable-tracing-instrumentation-log-debug)], $value) + AS_ECHO PPRINT_SUBTITLE([Install Directories])
diff --git a/src/lib/trace/debug.h b/src/lib/trace/debug.h index 87b3074e0..84a2867a6 100644 --- a/src/lib/trace/debug.h +++ b/src/lib/trace/debug.h @@ -6,8 +6,10 @@ * \brief Macros for debugging our event-trace support. **/
-#ifndef TOR_TRACE_LOG_DEBUG_H -#define TOR_TRACE_LOG_DEBUG_H +#ifndef TOR_TRACE_DEBUG_H +#define TOR_TRACE_DEBUG_H + +#ifdef USE_TRACING_INSTRUMENTATION_LOG_DEBUG
#include "lib/log/log.h"
@@ -17,14 +19,20 @@
/* Send every event to a debug log level. This is useful to debug new trace * events without implementing them for a specific event tracing framework. - * Note that the arguments are ignored since at this step we do not know the - * types and amount there is. */ + * + * NOTE: arguments can't be used becaue there is no easy generic ways to learn + * their type and amount. It is probably doable with massive C pre-processor + * trickery but this is meant to be simple. */ + +#define TOR_TRACE_LOG_DEBUG(subsystem, event_name, ...) \ + log_debug(LD_GENERAL, "Tracepoint "" XSTR(event_name) "" from " \ + "subsystem "" XSTR(subsystem) "" hit.") + +#else /* defined(USE_TRACING_INSTRUMENTATION_LOG_DEBUG) */ + +/* NOP the debug event. */ +#define TOR_TRACE_LOG_DEBUG(subsystem, name, ...)
-/* Example on how to map a tracepoint to log_debug(). */ -#undef tor_trace -#define tor_trace(subsystem, name, args...) \ - log_debug(LD_GENERAL, "Trace event "" XSTR(name) "" from " \ - """ XSTR(subsystem) "" hit. " \ - "(line "XSTR(__LINE__) ")") +#endif /* defined(USE_TRACING_INSTRUMENTATION_LOG_DEBUG) */
-#endif /* !defined(TOR_TRACE_LOG_DEBUG_H) */ +#endif /* !defined(TOR_TRACE_DEBUG_H) */ diff --git a/src/lib/trace/events.h b/src/lib/trace/events.h index 368f85dd0..b1b31fdc9 100644 --- a/src/lib/trace/events.h +++ b/src/lib/trace/events.h @@ -6,40 +6,28 @@ * \brief Header file for Tor event tracing. **/
-#ifndef TOR_TRACE_EVENTS_H -#define TOR_TRACE_EVENTS_H - -/* - * The following defines a generic event tracing function name that has to be - * used to trace events in the code base. - * - * That generic function is then defined by a event tracing framework. For - * instance, the "log debug" framework sends all trace events to log_debug() - * which is defined in src/trace/debug.h which can only be enabled at compile - * time (--enable-event-tracing-debug). - * - * By default, every trace events in the code base are replaced by a NOP. See - * doc/HACKING/Tracing.md for more information on how to use event tracing or - * add events. - */ - -#ifdef TOR_EVENT_TRACING_ENABLED -/* Map every trace event to a per subsystem macro. */ -#define tor_trace(subsystem, name, ...) \ - tor_trace_##subsystem(name, __VA_ARGS__) - -/* Enable event tracing for the debug framework where all trace events are - * mapped to a log_debug(). */ -#ifdef USE_EVENT_TRACING_DEBUG +#ifndef TOR_LIB_TRACE_EVENTS_H +#define TOR_LIB_TRACE_EVENTS_H + +/* XXX: DOCDOC once framework is stable. */ + +#ifdef HAVE_TRACING + +#define tor_trace(subsystem, event_name, ...) \ + do { \ + TOR_TRACE_LOG_DEBUG(tor_ ## subsystem, event_name); \ + } while (0) + +/* This corresponds to the --enable-tracing-instrumentation-log-debug + * configure option which maps all tracepoints to a log_debug() statement. */ #include "lib/trace/debug.h" -#endif
-#else /* !defined(TOR_EVENT_TRACING_ENABLED) */ +#else /* !defined(HAVE_TRACING) */
-/* Reaching this point, we NOP every event declaration because event tracing - * is not been enabled at compile time. */ -#define tor_trace(subsystem, name, args...) +/* Reaching this point, tracing is disabled thus we NOP every tracepoints + * declaration so we have no execution cost at runtime. */ +#define tor_trace(subsystem, name, ...)
-#endif /* defined(TOR_EVENT_TRACING_ENABLED) */ +#endif /* defined(HAVE_TRACING) */
-#endif /* !defined(TOR_TRACE_EVENTS_H) */ +#endif /* !defined(TOR_LIB_TRACE_EVENTS_H) */ diff --git a/src/lib/trace/include.am b/src/lib/trace/include.am index 98098c87f..1669943dc 100644 --- a/src/lib/trace/include.am +++ b/src/lib/trace/include.am @@ -2,18 +2,20 @@ noinst_LIBRARIES += \ src/lib/libtor-trace.a
+# ADD_C_FILE: INSERT SOURCES HERE. +LIBTOR_TRACE_A_SOURCES = \ + src/lib/trace/trace.c + # ADD_C_FILE: INSERT HEADERS HERE. TRACEHEADERS = \ src/lib/trace/trace.h \ src/lib/trace/events.h
-if USE_EVENT_TRACING_DEBUG +if USE_TRACING_INSTRUMENTATION_LOG_DEBUG TRACEHEADERS += \ src/lib/trace/debug.h endif
-# ADD_C_FILE: INSERT SOURCES HERE. -src_lib_libtor_trace_a_SOURCES = \ - src/lib/trace/trace.c +src_lib_libtor_trace_a_SOURCES = $(LIBTOR_TRACE_A_SOURCES)
noinst_HEADERS+= $(TRACEHEADERS)