[WIP: missing commit message] TBD

Signed-off-by: Jan Pokorný <[email protected]>

include/qb/qblog.h

@@ -298,16 +298,36 @@ typedef void (*qb_log_filter_fn)(struct qb_log_callsite * cs);
 #define QB_ATTR_SECTION_START_STR	QB_PP_STRINGIFY(QB_ATTR_SECTION_START)
 #define QB_ATTR_SECTION_STOP_STR	QB_PP_STRINGIFY(QB_ATTR_SECTION_STOP)
 
-extern struct qb_log_callsite QB_ATTR_SECTION_START[];
-extern struct qb_log_callsite QB_ATTR_SECTION_STOP[];
+extern struct qb_log_callsite QB_ATTR_SECTION_START[]
+#if !defined(QB_NOAPI_LOG_INT) && !defined(_GNU_SOURCE) && !defined(QB_LD_2_29)
+__attribute__((visibility ("protected")))
+#endif
+;
+extern struct qb_log_callsite QB_ATTR_SECTION_STOP[]
+#if !defined(QB_NOAPI_LOG_INT) && !defined(_GNU_SOURCE) && !defined(QB_LD_2_29)
+__attribute__((visibility ("protected")))
+#endif
+;
 
 /* Related to the next macro that is -- unlike this one -- a public API */
-#ifndef _GNU_SOURCE
+#if !defined(_GNU_SOURCE) && !defined(QB_LD_2_29)
+#define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name)				\
+        { _Pragma(QB_PP_STRINGIFY(GCC warning QB_PP_STRINGIFY(		\
+                  without "_GNU_SOURCE" defined (directly or not)	\
+                  QB_LOG_INIT_DATA cannot check sanity of libqb proper	\
+                  and only superficially of the target site originating	\
+                  this check alone.					\
+                  NOT COMPATIBLE WITH BINUTILS 2.29 (2.29.1 OK))));		\
+          /*  original, straightforward check */			\
+          assert("target's own callsite section is populated, otherwise \
+target's build is at fault, preventing reliable logging"		\
+           && QB_ATTR_SECTION_START != QB_ATTR_SECTION_STOP); }
+#elif !defined(_GNU_SOURCE)
 #define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name)				\
-	_Pragma(QB_PP_STRINGIFY(GCC warning QB_PP_STRINGIFY(		\
-	        without "_GNU_SOURCE" defined (directly or not) 	\
-		QB_LOG_INIT_DATA cannot check sanity of libqb proper	\
-		nor of the target site originating this check alone)))
+        _Pragma(QB_PP_STRINGIFY(GCC warning QB_PP_STRINGIFY(		\
+                without "_GNU_SOURCE" defined (directly or not) 	\
+                QB_LOG_INIT_DATA cannot check sanity of libqb proper	\
+                nor of the target site originating this check alone)))
 #else
 #define QB_NONAPI_LOG_INIT_DATA_EXTRA_(name)				\
     { Dl_info work_dli;							\
@@ -338,11 +358,11 @@ libqb's build is at fault, preventing reliable logging"			\
                   dlsym(work_handle, QB_ATTR_SECTION_START_STR);	\
         work_s2 = (struct qb_log_callsite *)				\
                   dlsym(work_handle, QB_ATTR_SECTION_STOP_STR);		\
-        assert("target's own callsite section observable, otherwise \
+        assert("target's own callsite section is observable, otherwise \
 target's own linkage at fault and logging would not work reliably \
 (unless QB_LOG_INIT_DATA macro used unexpectedly in no-logging context)"\
                && work_s1 != NULL && work_s2 != NULL);			\
-        assert("target's own callsite section non-empty, otherwise \
+        assert("target's own callsite section is populated, otherwise \
 target's own linkage at fault and logging would not work reliably \
 (unless QB_LOG_INIT_DATA macro used unexpectedly in no-logging context)"\
                && work_s1 != work_s2);					\
@@ -373,6 +393,12 @@ target's own linkage at fault and logging would not work reliably \
  * @c _GNU_SOURCE macro definition is present at compile-time means only half
  * of the available sanity checking will be performed, possibly resulting
  * in libqb's own internally logged messages being lost without warning.
+ *
+ * @note When this macro is leveraged in the end executable that is moreover
+ *       linked with ld.bfd from binutils 2.29 (2.29.1 is not of concern,
+ *       though), make sure the respective code is compiled with at least one
+ *       of @c _GNU_SOURCE and @c QB_LD_2_29 macros defined so as to avoid
+ *       run-time misbehaviour of the pertaining checks.
  */
 #define QB_LOG_INIT_DATA(name)						\
     void name(void);							\
@@ -390,11 +416,7 @@ target's own linkage at fault and logging would not work reliably \
 target's and/or libqb's build is at fault, preventing reliable logging" \
                && work_s1 != NULL && work_s2 != NULL);			\
         dlclose(work_handle);  /* perhaps overly eager thing to do */ }	\
-    QB_NONAPI_LOG_INIT_DATA_EXTRA_(name);				\
-    /* finally, original, straightforward check */			\
-    assert("implicit callsite section is populated, otherwise \
-target's build is at fault, preventing reliable logging"		\
-           && QB_ATTR_SECTION_START != QB_ATTR_SECTION_STOP); }		\
+    QB_NONAPI_LOG_INIT_DATA_EXTRA_(name);	 }		\
     void __attribute__ ((constructor)) name(void);
 #else
 #define QB_LOG_INIT_DATA(name)

lib/libqb.pc.in

@@ -16,8 +16,14 @@ Libs: -L${libdir} -lqb @client_dlopen_LIBS@
 #       possible future optimizations and extra features.  Consequently,
 #       logging issues (typically bound to QB_LOG_INIT_DATA macro) can be
 #       mitigated with QB_KILL_ATTRIBUTE_SECTION macro defined for a build.
-# NOTE: when concerned about a warning coming from the build process like
+# NOTE: Conversely, when QB_LOG_INIT_DATA macro is leveraged in the end
+#       executable relying on this library that is moreover linked with
+#       ld.bfd from binutils 2.29 (2.29.1 is not of concern, though), make
+#       sure the respective code is compiled with at least one of _GNU_SOURCE
+#       and QB_LD_2_29 macros defined so as to avoid run-time misbehaviour
+#       of the pertaining checks.
+# NOTE: When concerned about a warning coming from the build process like
 #       warning: [...]libqb.so contains output sections; did you forget -T?
-#       and the build finishes OK, take it merely as a harmless side-effect
+#       and the build finishes OK, take it merely as a harmless side-effect.
 Libs.private: @LIBS@
 Cflags: -I${includedir}

lib/log.c

@@ -18,6 +18,8 @@
  * You should have received a copy of the GNU Lesser General Public License
  * along with libqb.  If not, see <http://www.gnu.org/licenses/>.
  */
+#define QB_NOAPI_LOG_INT 1
+
 #include "os_base.h"
 #include <ctype.h>
 #ifdef HAVE_LINK_H