--- a/config/rules.mk
+++ b/config/rules.mk
@@ -897,16 +897,17 @@ src_libdep = $(call mk_libname,$1): $1 $
 
 # Rules for building native targets must come first because of the host_ prefix
 $(HOST_COBJS):
 	$(REPORT_BUILD)
 	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CPPOBJS):
 	$(REPORT_BUILD)
+	$(call BUILDSTATUS,OBJECT_FILE $@)
 	$(ELOG) $(HOST_CXX) $(HOST_OUTOPTION)$@ -c $(HOST_CXXFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CMOBJS):
 	$(REPORT_BUILD)
 	$(ELOG) $(HOST_CC) $(HOST_OUTOPTION)$@ -c $(HOST_CFLAGS) $(HOST_CMFLAGS) $(INCLUDES) $(NSPR_CFLAGS) $(_VPATH_SRCS)
 
 $(HOST_CMMOBJS):
 	$(REPORT_BUILD)
@@ -949,16 +950,17 @@ ifdef MOZ_RUST
 endif
 
 $(SOBJS):
 	$(REPORT_BUILD)
 	$(AS) -o $@ $(ASFLAGS) $($(notdir $<)_FLAGS) $(LOCAL_INCLUDES) $(TARGET_LOCAL_INCLUDES) -c $<
 
 $(CPPOBJS):
 	$(REPORT_BUILD)
+	$(call BUILDSTATUS,OBJECT_FILE $@)
 	@$(MAKE_DEPS_AUTO_CXX)
 	$(ELOG) $(CCC) $(OUTOPTION)$@ -c $(COMPILE_CXXFLAGS) $($(notdir $<)_FLAGS) $(TARGET_LOCAL_INCLUDES) $(_VPATH_SRCS)
 
 $(CMMOBJS):
 	$(REPORT_BUILD)
 	@$(MAKE_DEPS_AUTO_CXX)
 	$(ELOG) $(CCC) -o $@ -c $(COMPILE_CXXFLAGS) $(COMPILE_CMMFLAGS) $($(notdir $<)_FLAGS) $(TARGET_LOCAL_INCLUDES) $(_VPATH_SRCS)
 

--- a/python/mozbuild/mozbuild/controller/building.py
+++ b/python/mozbuild/mozbuild/controller/building.py
@@ -166,16 +166,18 @@ class BuildMonitor(MozbuildObject):
             try:
                 self.warnings_database.load_from_file(warnings_path)
             except ValueError:
                 os.remove(warnings_path)
 
         self._warnings_collector = WarningsCollector(
             database=self.warnings_database, objdir=self.topobjdir)
 
+        self.build_objects = []
+
     def start(self):
         """Record the start of the build."""
         self.start_time = time.time()
         self._finder_start_cpu = self._get_finder_cpu_usage()
 
     def start_resource_recording(self):
         # This should be merged into start() once bug 892342 lands.
         self.resources.start()
@@ -210,16 +212,19 @@ class BuildMonitor(MozbuildObject):
                 self.tiers.set_tiers(args)
                 update_needed = False
             elif action == 'TIER_START':
                 tier = args[0]
                 self.tiers.begin_tier(tier)
             elif action == 'TIER_FINISH':
                 tier, = args
                 self.tiers.finish_tier(tier)
+            elif action == 'OBJECT_FILE':
+                self.build_objects.append(args[0])
+                update_needed = False
             else:
                 raise Exception('Unknown build status: %s' % action)
 
             return BuildOutputResult(None, update_needed, False)
 
         warning = None
 
         try:
@@ -376,16 +381,17 @@ class BuildMonitor(MozbuildObject):
             argv=sys.argv,
             start=self.start_time,
             end=self.end_time,
             duration=self.end_time - self.start_time,
             resources=[],
             cpu_percent=cpu_percent,
             cpu_times=cpu_times,
             io=io,
+            objects=self.build_objects
         )
 
         o['tiers'] = self.tiers.tiered_resource_usage()
 
         self.tiers.add_resource_fields_to_dict(o)
 
         for usage in self.resources.range_usage():
             cpu_percent = self.resources.aggregate_cpu_percent(usage.start,