examples/c: replace llvm-strip symlink with BPF static linking

Rather than relying on the system's llvm-strip tool, which could be missing
and failing the build, use "bpftool" to generate bpf object files.

Signed-off-by: Rutvik Patel <[email protected]>

Author: heyrutvik

examples/c/Makefile

@@ -1,7 +1,6 @@
 # SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
 OUTPUT := .output
 CLANG ?= clang
-LLVM_STRIP ?= llvm-strip
 LIBBPF_SRC := $(abspath ../../libbpf/src)
 BPFTOOL_SRC := $(abspath ../../bpftool/src)
 LIBBPF_OBJ := $(abspath $(OUTPUT)/libbpf.a)
@@ -107,10 +106,12 @@ $(LIBBLAZESYM_HEADER): $(LIBBLAZESYM_SRC)/target/release/libblazesym.a | $(OUTPU
 	$(Q)cp $(LIBBLAZESYM_SRC)/target/release/blazesym.h $@
 
 # Build BPF code
-$(OUTPUT)/%.bpf.o: %.bpf.c $(LIBBPF_OBJ) $(wildcard %.h) $(VMLINUX) | $(OUTPUT)
+$(OUTPUT)/%.bpf.o: %.bpf.c $(LIBBPF_OBJ) $(wildcard %.h) $(VMLINUX) | $(OUTPUT) $(BPFTOOL)
 	$(call msg,BPF,$@)
-	$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(ARCH) $(INCLUDES) $(CLANG_BPF_SYS_INCLUDES) -c $(filter %.c,$^) -o $@
-	$(Q)$(LLVM_STRIP) -g $@ # strip useless DWARF info
+	$(Q)$(CLANG) -g -O2 -target bpf -D__TARGET_ARCH_$(ARCH)		      \
+		     $(INCLUDES) $(CLANG_BPF_SYS_INCLUDES)		      \
+		     -c $(filter %.c,$^) -o $(patsubst %.bpf.o,%.tmp.bpf.o,$@)
+	$(Q)$(BPFTOOL) gen object $@ $(patsubst %.bpf.o,%.tmp.bpf.o,$@)
 
 # Generate BPF skeletons
 $(OUTPUT)/%.skel.h: $(OUTPUT)/%.bpf.o | $(OUTPUT) $(BPFTOOL)