Fix compiler warnings about unused value in TRACE macros.

* src/debug.h: Change macros to not have a literal 0 as last
expression of the comma operator.
* src/debug.c (_gpgme_debug_frame_end): Return 0.
(_gpgme_debug): Return 0.
--

Instead of using
   foo(), 0
for the trace macros we let foo() return 0 instead.

Signed-off-by: Werner Koch <[email protected]>

2 files changed, 45 insertions, 37 deletions

diff --git a/src/debug.c b/src/debug.c
index ca0bb21a..292db555 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -80,11 +80,12 @@ _gpgme_debug_frame_begin (void)
 #endif
 }
 
-void _gpgme_debug_frame_end (void)
+int _gpgme_debug_frame_end (void)
 {
 #ifdef FRAME_NR
   frame_nr--;
 #endif
+  return 0;
 }
 
 
@@ -223,8 +224,17 @@ _gpgme_debug_subsystem_init (void)
 
 
 
-/* Log the formatted string FORMAT at debug level LEVEL or higher.  */
-void
+/* Log the formatted string FORMAT at debug level LEVEL or higher.
+ *
+ * Returns: 0
+ *
+ * Note that we always return 0 because the old TRACE macro evaluated
+ * to 0 which issues a warning with newer gcc version about an unused
+ * values.  By using a return value of this function this can be
+ * avoided.  Fixme: It might be useful to check whether the return
+ * value from the TRACE macros are actually used somewhere.
+ */
+int
 _gpgme_debug (int level, const char *format, ...)
 {
   va_list arg_ptr;
@@ -232,7 +242,7 @@ _gpgme_debug (int level, const char *format, ...)
 
   saved_errno = errno;
   if (debug_level < level)
-    return;
+    return 0;
 
   va_start (arg_ptr, format);
   LOCK (debug_lock);
@@ -273,6 +283,7 @@ _gpgme_debug (int level, const char *format, ...)
   fflush (errfp);
 
   gpg_err_set_errno (saved_errno);
+  return 0;
 }
 
 
diff --git a/src/debug.h b/src/debug.h
index d0db5736..6bde998f 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -64,7 +64,7 @@ int _gpgme_debug_set_debug_envvar (const char *value);
 void _gpgme_debug_subsystem_init (void);
 
 /* Log the formatted string FORMAT at debug level LEVEL or higher.  */
-void _gpgme_debug (int level, const char *format, ...);
+int  _gpgme_debug (int level, const char *format, ...);
 
 /* Start a new debug line in *LINE, logged at level LEVEL or higher,
    and starting with the formatted string FORMAT.  */
@@ -82,7 +82,7 @@ void _gpgme_debug_buffer (int lvl, const char *const fmt,
 			  size_t len);
 
 void _gpgme_debug_frame_begin (void);
-void _gpgme_debug_frame_end (void);
+int  _gpgme_debug_frame_end (void);
 
 static inline gpgme_error_t
 _gpgme_trace_gpgme_error (gpgme_error_t err, const char *file, int line)
@@ -108,82 +108,80 @@ _gpgme_trace_gpgme_error (gpgme_error_t err, const char *file, int line)
 #define TRACE_BEG(lvl, name, tag)			   \
   _TRACE (lvl, name, tag);				   \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p\n", \
-		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag), 0
+		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag)
 #define TRACE_BEG0(lvl, name, tag, fmt)					\
   _TRACE (lvl, name, tag);						\
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n",	\
-		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag), 0
+		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag)
 #define TRACE_BEG1(lvl, name, tag, fmt, arg1)				\
   _TRACE (lvl, name, tag);						\
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n",	\
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1), 0
+		arg1)
 #define TRACE_BEG2(lvl, name, tag, fmt, arg1, arg2)		    \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2), 0
+		arg1, arg2)
 #define TRACE_BEG3(lvl, name, tag, fmt, arg1, arg2, arg3)	    \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3), 0
+		arg1, arg2, arg3)
 #define TRACE_BEG4(lvl, name, tag, fmt, arg1, arg2, arg3, arg4)	    \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4), 0
+		arg1, arg2, arg3, arg4)
 #define TRACE_BEG5(lvl, name, tag, fmt, arg1, arg2, arg3, arg4, arg5) \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4, arg5), 0
+		arg1, arg2, arg3, arg4, arg5)
 #define TRACE_BEG7(lvl, name, tag, fmt, arg1, arg2, arg3, arg4,	    \
 		   arg5, arg6, arg7)				    \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4, arg5,	    \
-		arg6, arg7), 0
+		arg1, arg2, arg3, arg4, arg5, arg6, arg7)
 #define TRACE_BEG8(lvl, name, tag, fmt, arg1, arg2, arg3, arg4,	    \
 		   arg5, arg6, arg7, arg8)			    \
   _TRACE (lvl, name, tag);					    \
   _gpgme_debug (_gpgme_trace_level, "%s: enter: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4, arg5,	    \
-		arg6, arg7, arg8), 0
+		arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8)
 
 #define TRACE(lvl, name, tag)						\
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p\n",				\
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag),	\
-  _gpgme_debug_frame_end (), 0
+  _gpgme_debug_frame_end ()
 #define TRACE0(lvl, name, tag, fmt)					\
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p, " fmt "\n",			\
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag),	\
-  _gpgme_debug_frame_end (), 0
+  _gpgme_debug_frame_end ()
 #define TRACE1(lvl, name, tag, fmt, arg1)			       \
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p, " fmt "\n",		       \
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag, arg1), \
-  _gpgme_debug_frame_end (), 0
+  _gpgme_debug_frame_end ()
 #define TRACE2(lvl, name, tag, fmt, arg1, arg2)			       \
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p, " fmt "\n",		       \
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag, arg1, \
-		arg2), _gpgme_debug_frame_end (), 0
+		arg2), _gpgme_debug_frame_end ()
 #define TRACE3(lvl, name, tag, fmt, arg1, arg2, arg3)		       \
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p, " fmt "\n",		       \
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag, arg1, \
-		arg2, arg3), _gpgme_debug_frame_end (), 0
+		arg2, arg3), _gpgme_debug_frame_end ()
 #define TRACE6(lvl, name, tag, fmt, arg1, arg2, arg3, arg4, arg5, arg6)	\
   _gpgme_debug_frame_begin (),						\
   _gpgme_debug (lvl, "%s: call: %s=%p, " fmt "\n",			\
 		name, STRINGIFY (tag), (void *) (uintptr_t) tag, arg1, \
 		arg2, arg3, arg4, arg5, arg6),			       \
-  _gpgme_debug_frame_end (), 0
+  _gpgme_debug_frame_end ()
 
 #define TRACE_ERR(err)							\
   err == 0 ? (TRACE_SUC ()) :						\
@@ -203,53 +201,52 @@ _gpgme_trace_gpgme_error (gpgme_error_t err, const char *file, int line)
 
 #define TRACE_SUC()						 \
   _gpgme_debug (_gpgme_trace_level, "%s: leave\n",       \
-		_gpgme_trace_func), _gpgme_debug_frame_end (), 0
+		_gpgme_trace_func), _gpgme_debug_frame_end ()
 #define TRACE_SUC0(fmt)							\
   _gpgme_debug (_gpgme_trace_level, "%s: leave: " fmt "\n",	\
-		_gpgme_trace_func), _gpgme_debug_frame_end (), 0
+		_gpgme_trace_func), _gpgme_debug_frame_end ()
 #define TRACE_SUC1(fmt, arg1)						\
   _gpgme_debug (_gpgme_trace_level, "%s: leave: " fmt "\n",	\
-		_gpgme_trace_func, arg1), _gpgme_debug_frame_end (), 0
+		_gpgme_trace_func, arg1), _gpgme_debug_frame_end ()
 #define TRACE_SUC2(fmt, arg1, arg2)					\
   _gpgme_debug (_gpgme_trace_level, "%s: leave: " fmt "\n",	\
-		_gpgme_trace_func, arg1, arg2), _gpgme_debug_frame_end (), 0
+		_gpgme_trace_func, arg1, arg2), _gpgme_debug_frame_end ()
 #define TRACE_SUC5(fmt, arg1, arg2, arg3, arg4, arg5)			\
   _gpgme_debug (_gpgme_trace_level, "%s: leave: " fmt "\n",	\
 		_gpgme_trace_func, arg1, arg2, arg3, arg4, arg5), \
-    _gpgme_debug_frame_end (), 0
+    _gpgme_debug_frame_end ()
 #define TRACE_SUC6(fmt, arg1, arg2, arg3, arg4, arg5, arg6)	\
   _gpgme_debug (_gpgme_trace_level, "%s: leave: " fmt "\n",	\
 		_gpgme_trace_func, arg1, arg2, arg3, arg4, arg5, arg6),	\
-    _gpgme_debug_frame_end (), 0
+    _gpgme_debug_frame_end ()
 
 #define TRACE_LOG(fmt)							\
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n",	\
-		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag), 0
+		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag)
 #define TRACE_LOG1(fmt, arg1)						\
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n",	\
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1), 0
+		arg1)
 #define TRACE_LOG2(fmt, arg1, arg2)				    \
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2), 0
+		arg1, arg2)
 #define TRACE_LOG3(fmt, arg1, arg2, arg3)			    \
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3), 0
+		arg1, arg2, arg3)
 #define TRACE_LOG4(fmt, arg1, arg2, arg3, arg4)			    \
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4), 0
+		arg1, arg2, arg3, arg4)
 #define TRACE_LOG5(fmt, arg1, arg2, arg3, arg4, arg5)		    \
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4, arg5), 0
+		arg1, arg2, arg3, arg4, arg5)
 #define TRACE_LOG6(fmt, arg1, arg2, arg3, arg4, arg5, arg6)	    \
   _gpgme_debug (_gpgme_trace_level, "%s: check: %s=%p, " fmt "\n", \
 		_gpgme_trace_func, _gpgme_trace_tagname, _gpgme_trace_tag, \
-		arg1, arg2, arg3, arg4, arg5,	    \
-		arg6), 0
+		arg1, arg2, arg3, arg4, arg5, arg6)
 
 #define TRACE_LOGBUF(buf, len)					\
   _gpgme_debug_buffer (_gpgme_trace_level, "%s: check: %s",	\