build-scx-scheds: collect BPF progs into $OUTPUT_DIR/bpf

Update scx build script to explicitly collect BPF programs in addition
to copying raw build directories.

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>

Author: theihor

build-scx-scheds/build-scheds.sh

@@ -15,15 +15,30 @@ fi
 
 pushd $SCX_ROOT
 
-rm -rf $OUTPUT_DIR && mkdir -p $OUTPUT_DIR
+rm -rf $OUTPUT_DIR && mkdir -p $OUTPUT_DIR/bpf
+
+extract_bpf_progs() {
+    build_dir=$1
+    pattern=$2
+    bpf_dir=$3
+    find "${build_dir}" -type f -name "$pattern" -printf '%P\0' | \
+    while IFS= read -r -d '' prog; do
+        obj_name=$(echo "${prog}" | tr / _)
+        cp -v "${build_dir}/${prog}" "${bpf_dir}/${obj_name}"
+    done
+}
 
 # build C scheds
+# .SECONDARY prevents make from deleting the intermediate .bpf.o files
+echo '.SECONDARY:' >> scheds/c/Makefile
 make all -j$(nproc)
-mv build $OUTPUT_DIR/c-scheds
+mv build $OUTPUT_DIR/c-build
+extract_bpf_progs $OUTPUT_DIR/c-build/scheds "*.bpf.o" $OUTPUT_DIR/bpf
 
 # build Rust scheds
 . $HOME/.cargo/env
 cargo build --release
-mv target/release/build $OUTPUT_DIR/rust-scheds
+mv target/release/build $OUTPUT_DIR/rust-build
+extract_bpf_progs $OUTPUT_DIR/rust-build "bpf.bpf.o" $OUTPUT_DIR/bpf
 
 popd