[ion] Add a host command-line utility to filter valid events

Change-Id: Iaaa26ebf079152592a973c1f4658caa00f3f0651

ion/Makefile

@@ -4,12 +4,12 @@ ifdef GIT
   PATCH_LEVEL = `git rev-parse HEAD`
 endif
 
-
-
 SFLAGS += -Iion/include -DKD_CONFIG_H=1
 ion/src/shared/software_version.o: SFLAGS += -DPATCH_LEVEL=$(PATCH_LEVEL) -DVERSION=$(VERSION)
 include ion/src/$(PLATFORM)/Makefile
 
+include ion/src/shared/tools/Makefile
+
 objs += $(addprefix ion/src/shared/, \
   events.o \
   software_version.o \

ion/src/shared/tools/Makefile

@@ -0,0 +1,5 @@
+ion/src/shared/tools/event_%: ion/src/shared/tools/event_%.cpp ion/src/shared/events.cpp
+	@echo "HOSTCXX $@"
+	@$(HOSTCXX) -std=c++11 -Iion/include $^ -o $@
+
+products += $(addprefix ion/src/shared/tools/, event_filter event_generator)

ion/src/shared/tools/event_filter.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+#include <ion/events.h>
+
+int main(int argc, char * argv[]) {
+  char c;
+  while (std::cin.get(c)) {
+    Ion::Events::Event e(c);
+    if (e.isValid()) {
+      std::cout.put(c);
+    }
+  }
+}