[PATCH 2/4] perf: Add define for libtraceevent version

[Ian Rogers]

The definition is derived from pkg-config as discussed in:
https://lore.kernel.org/lkml/20210610155915.20a252d3@xxxxxxxxxxxxxxxx/
The definition is computed using expr rather than passed to be computed
in C code, this avoids complications with quote  in the variable
expansions. For example see the target python/perf.so in Makefile.perf.

Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
---
 tools/perf/Makefile.config | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 3a8a54b71654..6f318c16e8f1 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -1093,6 +1093,12 @@ ifdef LIBTRACEEVENT_DYNAMIC
   $(call feature_check,libtraceevent)
   ifeq ($(feature-libtraceevent), 1)
     EXTLIBS += -ltraceevent
+    LIBTRACEEVENT_VERSION := $(shell $(PKG_CONFIG) --modversion libtraceevent)
+    LIBTRACEEVENT_VERSION_1 := $(word 1, $(subst ., ,$(LIBTRACEEVENT_VERSION)))
+    LIBTRACEEVENT_VERSION_2 := $(word 2, $(subst ., ,$(LIBTRACEEVENT_VERSION)))
+    LIBTRACEEVENT_VERSION_3 := $(word 3, $(subst ., ,$(LIBTRACEEVENT_VERSION)))
+    LIBTRACEEVENT_VERSION_CPP := $(shell expr $(LIBTRACEEVENT_VERSION_1) \* 255 \* 255 + $(LIBTRACEEVENT_VERSION_2) \* 255 + $(LIBTRACEEVENT_VERSION_3))
+    CFLAGS += -DLIBTRACEEVENT_VERSION=$(LIBTRACEEVENT_VERSION_CPP)
   else
     dummy := $(error Error: No libtraceevent devel library found, please install libtraceevent-devel);
   endif
-- 
2.32.0.288.g62a8d224e6-goog