From 2a9d30fac818ffc97ecfa2f71019181a631b9c9b Mon Sep 17 00:00:00 2001 From: Daniel Xu Date: Thu, 30 Jan 2025 15:33:45 -0700 Subject: [PATCH] selftests/bpf: Support dynamically linking LLVM if static is not available Since 67ab80a01886 ("selftests/bpf: Prefer static linking for LLVM libraries"), only statically linking test_progs is supported. However, some distros only provide a dynamically linkable LLVM. This commit adds a fallback for dynamically linking LLVM if static linking is not available. If both options are available, static linking is chosen. Signed-off-by: Daniel Xu Signed-off-by: Andrii Nakryiko Tested-by: Eduard Zingerman Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/872b64e93de9a6cd6a7a10e6a5c5e7893704f743.1738276344.git.dxu@dxuuu.xyz --- tools/testing/selftests/bpf/Makefile | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 6722080b2107..da514030a153 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -184,9 +184,14 @@ ifeq ($(feature-llvm),1) LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets # both llvm-config and lib.mk add -D_GNU_SOURCE, which ends up as conflict LLVM_CFLAGS += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags)) - LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --libs $(LLVM_CONFIG_LIB_COMPONENTS)) - LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --system-libs $(LLVM_CONFIG_LIB_COMPONENTS)) - LLVM_LDLIBS += -lstdc++ + # Prefer linking statically if it's available, otherwise fallback to shared + ifeq ($(shell $(LLVM_CONFIG) --link-static --libs &> /dev/null && echo static),static) + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --libs $(LLVM_CONFIG_LIB_COMPONENTS)) + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-static --system-libs $(LLVM_CONFIG_LIB_COMPONENTS)) + LLVM_LDLIBS += -lstdc++ + else + LLVM_LDLIBS += $(shell $(LLVM_CONFIG) --link-shared --libs $(LLVM_CONFIG_LIB_COMPONENTS)) + endif LLVM_LDFLAGS += $(shell $(LLVM_CONFIG) --ldflags) endif -- 2.25.1