Re: [PATCH v2 1/2] tools lib traceevent: Export dynamic symbols used by traceevent plugins

[Jiri Olsa <jolsa@redhat.com>]

On Tue, May 12, 2015 at 06:41:56AM +0000, He Kuang wrote:

SNIP

>  	$(Q)$(MAKE) $(build)=perf
>  
> -$(OUTPUT)perf: $(PERFLIBS) $(PERF_IN)
> -	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(PERF_IN) $(LIBS) -o $@
> +LD_LIBTRACEEVENT_FLAGS += -Xlinker --dynamic-list=$(LIBTRACEEVENT_DYNAMIC_LIST)
> +$(OUTPUT)perf: $(PERFLIBS) $(PERF_IN) $(LIBTRACEEVENT_DYNAMIC_LIST)
> +	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $(LD_LIBTRACEEVENT_FLAGS) $(PERF_IN) $(LIBS) -o $@
>  
>  $(GTK_IN): FORCE
>  	$(Q)$(MAKE) $(build)=gtk
> @@ -373,7 +375,13 @@ $(LIB_FILE): $(LIBPERF_IN)
>  LIBTRACEEVENT_FLAGS += plugin_dir=$(plugindir_SQ)
>  
>  $(LIBTRACEEVENT): FORCE
> -	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) $(OUTPUT)libtraceevent.a plugins
> +	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) $(OUTPUT)libtraceevent.a
> +
> +libtraceevent_plugins: FORCE
> +	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) plugins
> +
> +$(LIBTRACEEVENT_DYNAMIC_LIST): libtraceevent_plugins
> +	$(Q)$(MAKE) -C $(TRACE_EVENT_DIR) $(LIBTRACEEVENT_FLAGS) O=$(OUTPUT) $(OUTPUT)libtraceevent-dynamic-list

I thought the idea of v2 was not to introduce new target,
something like in attached patch (not completely tested)

jirka


---
diff --git a/tools/lib/traceevent/Makefile b/tools/lib/traceevent/Makefile
index d410da335e3d..57eed0403e6a 100644
--- a/tools/lib/traceevent/Makefile
+++ b/tools/lib/traceevent/Makefile
@@ -23,6 +23,7 @@ endef
 # Allow setting CC and AR, or setting CROSS_COMPILE as a prefix.
 $(call allow-override,CC,$(CROSS_COMPILE)gcc)
 $(call allow-override,AR,$(CROSS_COMPILE)ar)
+$(call allow-override,NM,$(CROSS_COMPILE)nm)
 
 EXT = -std=gnu99
 INSTALL = install
@@ -169,7 +170,10 @@ $(OUTPUT)libtraceevent.so: $(TE_IN)
 $(OUTPUT)libtraceevent.a: $(TE_IN)
 	$(QUIET_LINK)$(RM) $@; $(AR) rcs $@ $^
 
-plugins: $(PLUGINS)
+$(OUTPUT)libtraceevent-dynamic-list: $(PLUGINS)
+	$(QUIET_GEN)$(call do_generate_dynamic_list_file, $(PLUGINS), $@)
+
+plugins: $(OUTPUT)libtraceevent-dynamic-list
 
 __plugin_obj = $(notdir $@)
   plugin_obj = $(__plugin_obj:-in.o=)
@@ -238,6 +242,13 @@ define do_install_plugins
 	done
 endef
 
+define do_generate_dynamic_list_file
+	(echo '{';							\
+	$(NM) -u -D $1 | awk 'NF>1 {print "\t"$$2";"}' | sort -u;	\
+	echo '};';							\
+	) > $2
+endef
+
 install_lib: all_cmd install_plugins
 	$(call QUIET_INSTALL, $(LIB_FILE)) \
 		$(call do_install,$(LIB_FILE),$(bindir_SQ))
diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf
index 03409cc02117..a8db98649ea3 100644
--- a/tools/perf/Makefile.perf
+++ b/tools/perf/Makefile.perf
@@ -173,6 +173,8 @@ endif
 LIBTRACEEVENT = $(TE_PATH)libtraceevent.a
 export LIBTRACEEVENT
 
+LDFLAGS += -Xlinker --dynamic-list=$(TE_PATH)libtraceevent-dynamic-list
+
 LIBAPI = $(LIB_PATH)libapi.a
 export LIBAPI