Fix c99 compatibility: tp_rcu_dereference_bp() should not use braced-groups within...

Allow tp_rcu_dereference_bp() to be used within programs compiled with
--std=c99 -pedantic -Werror. Fixes the following:

In file included from hello.c:34:0:
ust_tests_hello.h: In function ‘__tracepoint_cb_ust_tests_hello___tptest’:
ust_tests_hello.h:28:1: warning: ISO C forbids braced-groups within expressions [-pedantic]
ust_tests_hello.h:28:1: warning: ISO C forbids conversion of object pointer to function pointer type [-pedantic]

We can easily fix this one since tp_rcu_dereference_bp() really
evaluates only a single expression.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/include/lttng/tracepoint-rcu.h b/include/lttng/tracepoint-rcu.h
index a754048cc51ccc624a028c522aa8a030fbf04fcf..2e0a79fd02d6cf88363252393a4f13011eedfb78 100644 (file)
--- a/include/lttng/tracepoint-rcu.h
+++ b/include/lttng/tracepoint-rcu.h
@@ -31,12 +31,9 @@
 #define tp_rcu_read_lock_bp    tracepoint_dlopen.rcu_read_lock_sym_bp
 #define tp_rcu_read_unlock_bp  tracepoint_dlopen.rcu_read_unlock_sym_bp
 
-#define tp_rcu_dereference_bp(p)                                            \
-       ({                                                                   \
-               __typeof__(p) _________p1 = URCU_FORCE_CAST(__typeof__(p),   \
-                       tracepoint_dlopen.rcu_dereference_sym_bp(URCU_FORCE_CAST(void *, p))); \
-               (_________p1);                                               \
-       })
+#define tp_rcu_dereference_bp(p)                                          \
+               URCU_FORCE_CAST(__typeof__(p),                             \
+                       tracepoint_dlopen.rcu_dereference_sym_bp(URCU_FORCE_CAST(void *, p)))
 
 #define TP_RCU_LINK_TEST()     tp_rcu_read_lock_bp
 

diff --git a/tests/hello/Makefile.am b/tests/hello/Makefile.am
index 0c4c3113bcdcaa6d8a7154e44f550b9e8e5fb40a..4abfd580a47226e9c8c60d527ef553ff1e826dcb 100644 (file)
--- a/tests/hello/Makefile.am
+++ b/tests/hello/Makefile.am
@@ -1,9 +1,10 @@
 AM_CPPFLAGS = -I$(top_srcdir)/include -Wsystem-headers
 
 noinst_PROGRAMS = hello
-hello_SOURCES = hello.c tp.c ust_tests_hello.h
+#hello_SOURCES = hello.c tp.c ust_tests_hello.h
+hello_SOURCES = hello.c ust_tests_hello.h
 hello_LDADD = $(top_builddir)/liblttng-ust/liblttng-ust.la
-hello_CFLAGS = -Werror=old-style-definition
+hello_CFLAGS = -Werror=old-style-definition --std=c99 -pedantic
 
 if LTTNG_UST_BUILD_WITH_LIBDL
 hello_LDADD += -ldl