From 7e1f74bbbed7d3bf2f0597f820eba15ec70f35fa Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Sat, 30 May 2026 18:09:24 -0700 Subject: [PATCH] tools build: Fix feature checks to touch target files on success In tools/build/feature/Makefile, test-clang-bpf-co-re.bin and test-bpftool-skeletons.bin redirected grep output but never touched or created the $@ target file upon success. Because the target file was never created on disk, Kbuild could never cache the result of the check. Consequently, Make treated the prerequisite as missing and continuously re-executed the Clang BPF backend and bpftool feature checks on every single sub-make evaluation during build startup, or on every incremental build. Refactor both feature check recipes to touch $@ on success. For test-clang-bpf-co-re.bin, group the shell pipeline within curly braces and redirect both stdout and stderr to .make.output to allow errors to be inspected and not appear in build output. List test-clang-bpf-co-re.bin's input C file as a dependency so modification triggers a rebuild. For test-bpftool-skeletons.bin, add it to the FILES list so that it will be cleaned. Assisted-by: Gemini:gemini-3.1-pro-preview Signed-off-by: Ian Rogers Tested-by: James Clark Cc: Bill Wendling Cc: Costa Shulyupin Cc: Dmitrii Dolgov <9erthalion6@gmail.com> Cc: Justin Stitt Cc: Leo Yan Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Yuzhuo Jing Signed-off-by: Arnaldo Carvalho de Melo --- tools/build/feature/Makefile | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile index 4e4a92ef5e1e7..9da5a4fd956a8 100644 --- a/tools/build/feature/Makefile +++ b/tools/build/feature/Makefile @@ -72,7 +72,8 @@ FILES= \ test-file-handle.bin \ test-libpfm4.bin \ test-rust.bin \ - test-libopenssl.bin + test-libopenssl.bin \ + test-bpftool-skeletons.bin FILES := $(addprefix $(OUTPUT),$(FILES)) @@ -379,9 +380,9 @@ $(OUTPUT)test-libaio.bin: $(OUTPUT)test-libzstd.bin: $(BUILD) -lzstd -$(OUTPUT)test-clang-bpf-co-re.bin: - $(CLANG) -S -g --target=bpf -o - $(patsubst %.bin,%.c,$(@F)) | \ - grep BTF_KIND_VAR +$(OUTPUT)test-clang-bpf-co-re.bin: test-clang-bpf-co-re.c + { $(CLANG) -S -g --target=bpf -o - $< | \ + grep BTF_KIND_VAR; } > $(@:.bin=.make.output) 2>&1 && touch $@ $(OUTPUT)test-file-handle.bin: $(BUILD) @@ -393,8 +394,8 @@ $(OUTPUT)test-libopenssl.bin: $(BUILD) $(shell $(PKG_CONFIG) --libs --cflags openssl 2>/dev/null) $(OUTPUT)test-bpftool-skeletons.bin: - $(SYSTEM_BPFTOOL) version | grep '^features:.*skeletons' \ - > $(@:.bin=.make.output) 2>&1 + { $(SYSTEM_BPFTOOL) version | grep '^features:.*skeletons'; } \ + > $(@:.bin=.make.output) 2>&1 && touch $@ # Testing Rust is special: we don't compile anything, it's enough to check the # compiler presence. Compiling a test code for this purposes is problematic, -- 2.47.3