[RFC PATCH bpf-next v5 3/8] selftests/bpf: factor the permissive-mode skip suffix into a helper

[Mykola Lysenko <nickolay.lysenko@gmail.com>]

With BPF_STRICT_BUILD=0, eleven recipes append the same "|| { remove
the target, print a SKIP marker, report success }" tail, each spelled
out inline. Factor the tail into skip_on_fail, parameterized by the
SKIP tag, optional extra files to remove alongside the target and an
optional note appended to the message - every call site keeps its
exact message and behavior.

The permissive fragments of other shapes are not suffixes and keep
their current form: the rsync --ignore-missing-args flags, the
missing-input guards in the skeleton recipes, the link rule's
wildcard handling and the test_kmods copy wrapper.

Signed-off-by: Mykola Lysenko <nickolay.lysenko@gmail.com>
---
 tools/testing/selftests/bpf/Makefile | 49 +++++++++++-----------------
 1 file changed, 19 insertions(+), 30 deletions(-)

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 69093fba3..565862247 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -49,6 +49,14 @@ SKIP_CRYPTO	?=
 BPF_STRICT_BUILD ?= 1
 PERMISSIVE := $(filter 0,$(BPF_STRICT_BUILD))
 
+# Permissive-mode recipe suffix: on failure, remove the target, emit a
+# SKIP marker and report success so the rest of the build continues.
+# $(1) - SKIP tag (BPF, TEST, BENCH, SKEL, LINK, ...)
+# $(2) - optional extra files to remove alongside the target
+# $(3) - optional note appended to the SKIP message
+skip_on_fail = $(if $(PERMISSIVE),|| { $(RM) $@ $(2); \
+	printf '  %-12s %s\n' 'SKIP-$(1)' '$(notdir $@)$(if $(3), $(3))' 1>&2; })
+
 ifeq ($(srctree),)
 srctree := $(patsubst %/,%,$(dir $(CURDIR)))
 srctree := $(patsubst %/,%,$(dir $(srctree)))
@@ -495,26 +503,22 @@ $(addprefix $(OUTPUT)/,cgroup_getset_retval_hooks.bpf.o \
 # $4 - binary name
 define CLANG_BPF_BUILD_RULE
 	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v3 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
+	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v3 -o $2 $(call skip_on_fail,BPF)
 endef
 # Similar to CLANG_BPF_BUILD_RULE, but with disabled alu32
 define CLANG_NOALU32_BPF_BUILD_RULE
 	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v2 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
+	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v2 -o $2 $(call skip_on_fail,BPF)
 endef
 # Similar to CLANG_BPF_BUILD_RULE, but with cpu-v4
 define CLANG_CPUV4_BPF_BUILD_RULE
 	$(call msg,CLNG-BPF,$4,$2)
-	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v4 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
+	$(Q)$(CLANG) $3 -O2 $(BPF_TARGET_ENDIAN) -c $1 -mcpu=v4 -o $2 $(call skip_on_fail,BPF)
 endef
 # Build BPF object using GCC
 define GCC_BPF_BUILD_RULE
 	$(call msg,GCC-BPF,$4,$2)
-	$(Q)$(BPF_GCC) $3 -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes -O2 -c $1 -o $2 $(if $(PERMISSIVE),|| \
-		($(RM) $2; printf '  %-12s %s\n' 'SKIP-BPF' '$(notdir $2)' 1>&2))
+	$(Q)$(BPF_GCC) $3 -DBPF_NO_PRESERVE_ACCESS_INDEX -Wno-attributes -O2 -c $1 -o $2 $(call skip_on_fail,BPF)
 endef
 
 SKEL_BLACKLIST := btf__% test_pinning_invalid.c test_sk_assign.c
@@ -645,10 +649,7 @@ $(TRUNNER_BPF_SKELS): %.skel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
 	$$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o) && \
 	diff $$(<:.o=.linked2.o) $$(<:.o=.linked3.o) &&		\
 	$$(BPFTOOL) gen skeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$@ && \
-	$$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$(@:.skel.h=.subskel.h) $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@ $$(@:.skel.h=.subskel.h); \
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \
-	}) && \
+	$$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.bpf.o=)) > $$(@:.skel.h=.subskel.h) $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) && \
 	rm -f $$(<:.o=.linked1.o) $$(<:.o=.linked2.o) $$(<:.o=.linked3.o)
 
 $(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
@@ -662,10 +663,7 @@ $(TRUNNER_BPF_LSKELS): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
 	$$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o) && \
 	$$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o) && \
 	diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) &&		\
-	$$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@; \
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \
-	}) && \
+	$$(BPFTOOL) gen skeleton -L $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $$(call skip_on_fail,SKEL) && \
 	rm -f $$(<:.o=.llinked1.o) $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o)
 
 $(TRUNNER_BPF_LSKELS_SIGNED): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
@@ -679,10 +677,7 @@ $(TRUNNER_BPF_LSKELS_SIGNED): %.lskel.h: %.bpf.o $(BPFTOOL) | $(TRUNNER_OUTPUT)
 	$$(BPFTOOL) gen object $$(<:.o=.llinked2.o) $$(<:.o=.llinked1.o) && \
 	$$(BPFTOOL) gen object $$(<:.o=.llinked3.o) $$(<:.o=.llinked2.o) && \
 	diff $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o) &&		\
-	$$(BPFTOOL) gen skeleton $(LSKEL_SIGN) $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@; \
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \
-	}) && \
+	$$(BPFTOOL) gen skeleton $(LSKEL_SIGN) $$(<:.o=.llinked3.o) name $$(notdir $$(<:.bpf.o=_lskel)) > $$@ $$(call skip_on_fail,SKEL) && \
 	rm -f $$(<:.o=.llinked1.o) $$(<:.o=.llinked2.o) $$(<:.o=.llinked3.o)
 
 $(LINKED_BPF_OBJS): %: $(TRUNNER_OUTPUT)/%
@@ -704,10 +699,7 @@ $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_OUTPUT)/%: $$$$(%-deps) $(BPFTOOL) | $(TR
 	diff $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked3.o) &&	\
 	printf '  %-12s %s\n' 'GEN-SKEL' '[$(TRUNNER_BINARY)] $$(notdir $$@)' 1>&2 && \
 	$$(BPFTOOL) gen skeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$@ && \
-	$$(BPFTOOL) gen subskeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$(@:.skel.h=.subskel.h) $(if $(PERMISSIVE),|| { \
-		$$(RM) $$@ $$(@:.skel.h=.subskel.h);			\
-		printf '  %-12s %s\n' 'SKIP-SKEL' '$$(notdir $$@)' 1>&2; \
-	}) &&									\
+	$$(BPFTOOL) gen subskeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$(@:.skel.h=.subskel.h) $$(call skip_on_fail,SKEL,$$(@:.skel.h=.subskel.h)) &&									\
 	rm -f $$(@:.skel.h=.linked1.o) $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked3.o)
 
 # When the compiler generates a %.d file, only skel basenames (not
@@ -740,8 +732,7 @@ $(TRUNNER_TEST_OBJS): $(TRUNNER_OUTPUT)/%.test.o:			\
 		      $(TRUNNER_TESTS_DIR)/%.c				\
 		      | $(TRUNNER_OUTPUT)/%.test.d
 	$$(call msg,TEST-OBJ,$(TRUNNER_BINARY),$$@)
-	$(Q)(cd $$(@D) && $$(CC) -I. $$(CFLAGS) -MMD -MT $$@ -c $(CURDIR)/$$< $$(LDLIBS) -o $$(@F)) $(if $(filter test_progs%,$1),$(if $(PERMISSIVE),|| \
-		($(RM) $$@; printf '  %-12s %s\n' 'SKIP-TEST' '$$(notdir $$@)' 1>&2)))
+	$(Q)(cd $$(@D) && $$(CC) -I. $$(CFLAGS) -MMD -MT $$@ -c $(CURDIR)/$$< $$(LDLIBS) -o $$(@F)) $(if $(filter test_progs%,$1),$$(call skip_on_fail,TEST))
 	$$(if $$(TEST_NEEDS_BTFIDS),						\
 		$(Q)if [ -f $$@ ]; then						\
 		$(if $(filter 1,$(V)),true,printf '  %-8s%s %s\n' "BTFIDS" " [$(TRUNNER_BINARY)]" "$$(notdir $$@)"); \
@@ -962,8 +953,7 @@ $(OUTPUT)/test_cpp: test_cpp.cpp $(OUTPUT)/test_core_extern.skel.h $(BPFOBJ)
 # Benchmark runner
 $(OUTPUT)/bench_%.o: benchs/bench_%.c bench.h $(BPFOBJ)
 	$(call msg,CC,,$@)
-	$(Q)$(CC) $(CFLAGS) -O2 -c $(filter %.c,$^) $(LDLIBS) -o $@ $(if $(PERMISSIVE),|| \
-		($(RM) $@; printf '  %-12s %s\n' 'SKIP-BENCH' '$(notdir $@)' 1>&2))
+	$(Q)$(CC) $(CFLAGS) -O2 -c $(filter %.c,$^) $(LDLIBS) -o $@ $(call skip_on_fail,BENCH)
 $(OUTPUT)/bench_rename.o: $(OUTPUT)/test_overhead.skel.h
 $(OUTPUT)/bench_trigger.o: $(OUTPUT)/trigger_bench.skel.h
 $(OUTPUT)/bench_ringbufs.o: $(OUTPUT)/ringbuf_bench.skel.h \
@@ -1012,8 +1002,7 @@ $(OUTPUT)/bench: $(OUTPUT)/bench.o \
 		 $(OUTPUT)/usdt_2.o \
 		 #
 	$(call msg,BINARY,,$@)
-	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@ $(if $(PERMISSIVE),|| \
-		($(RM) $@; printf '  %-12s %s\n' 'SKIP-LINK' '$(notdir $@) (some benchmarks may have been skipped)' 1>&2))
+	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) $(filter %.a %.o,$^) $(LDLIBS) -o $@ $(call skip_on_fail,LINK,,(some benchmarks may have been skipped))
 
 # This works around GCC warning about snprintf truncating strings like:
 #
-- 
2.43.0