selftests/bpf: Add SKIP_LLVM makefile variable

Introduce SKIP_LLVM makefile variable that allows to avoid using llvm
dependencies when building BPF selftests. This is different from
existing feature-llvm, as the latter is a result of automatic detection
and should not be set by user explicitly.
Avoiding llvm dependencies could be useful for environments that do not
have them, given that as of now llvm dependencies are required only by
jit_disasm_helpers.c.

Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250522013813.125428-1-mykyta.yatsenko5@gmail.com

diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 27db3bf20c21e9ae1e91e62031ba1f03d3c395dd..cf5ed3bee573e45bc3fe6d32d074fd6a25fed008 100644 (file)
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -34,6 +34,9 @@ OPT_FLAGS     ?= $(if $(RELEASE),-O2,-O0)
 LIBELF_CFLAGS  := $(shell $(PKG_CONFIG) libelf --cflags 2>/dev/null)
 LIBELF_LIBS    := $(shell $(PKG_CONFIG) libelf --libs 2>/dev/null || echo -lelf)
 
+SKIP_DOCS      ?=
+SKIP_LLVM      ?=
+
 ifeq ($(srctree),)
 srctree := $(patsubst %/,%,$(dir $(CURDIR)))
 srctree := $(patsubst %/,%,$(dir $(srctree)))
@@ -172,6 +175,7 @@ override OUTPUT := $(patsubst %/,%,$(OUTPUT))
 endif
 endif
 
+ifneq ($(SKIP_LLVM),1)
 ifeq ($(feature-llvm),1)
   LLVM_CFLAGS  += -DHAVE_LLVM_SUPPORT
   LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
@@ -187,6 +191,7 @@ ifeq ($(feature-llvm),1)
   endif
   LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags)
 endif
+endif
 
 SCRATCH_DIR := $(OUTPUT)/tools
 BUILD_DIR := $(SCRATCH_DIR)/build