Use extern objects for the eBPF test framework.

backends/ebpf/runtime/runtime.mk

@@ -7,6 +7,8 @@ BPFOBJ=
 BPFNAME=$(basename $(BPFOBJ))
 BPFDIR=$(dir $(BPFOBJ))
 override INCLUDES+= -I$(dir $(BPFOBJ))
+# This can be any file with the extension ".c"
+EXTERNOBJ=
 
 # Arguments for the P4 Compiler
 P4INCLUDE=-I./p4include
@@ -31,7 +33,7 @@ SOURCE_BASE= $(ROOT_DIR)ebpf_runtime.c $(ROOT_DIR)pcap_util.c
 SOURCE_BASE+= $(ROOT_DIR)ebpf_runtime_$(TARGET).c
 # Add the generated file and externs to the base sources
 override SOURCES+= $(SOURCE_BASE)
-SRC_PROCESSED= $(notdir $(SOURCES))
+SRC_PROCESSED= $(notdir $(SOURCES)) $(EXTERNOBJ)
 OBJECTS = $(SRC_PROCESSED:%.c=$(BUILDDIR)/%.o)
 DEPS = $(OBJECTS:%.o=%.d)
 

backends/ebpf/targets/test_target.py

@@ -44,10 +44,7 @@ def compile_dataplane(self):
         # include the src of libbpf directly, does not require installation
         args += f"INCLUDES+=-I{self.runtimedir}/contrib/libbpf/src "
         if self.options.extern:
-            # we inline the extern so we need a direct include
-            args += f"INCLUDES+=-include{self.options.extern} "
-            # need to include the temporary dir because of the tmp import
-            args += f"INCLUDES+=-I{self.tmpdir} "
+            args += f"EXTERNOBJ+={self.options.extern} "
         result = testutils.exec_process(args)
         if result.returncode != testutils.SUCCESS:
             testutils.log.error("Failed to build the filter")