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authorAlexei Starovoitov <ast@kernel.org>2023-12-26 22:11:43 +0300
committerAndrii Nakryiko <andrii@kernel.org>2024-01-03 21:41:22 +0300
commit495d2d8133fd1407519170a5238f455abbd9ec9b (patch)
tree12f60945f5c43cbd7daaaf7be7e3594612a477c4 /tools/testing/selftests/bpf/Makefile
parenta640de4cf9fec0caf43ccb7404ec9f0fde9a6a65 (diff)
downloadlinux-495d2d8133fd1407519170a5238f455abbd9ec9b.tar.xz
selftests/bpf: Attempt to build BPF programs with -Wsign-compare
GCC's -Wall includes -Wsign-compare while clang does not. Since BPF programs are built with clang we need to add this flag explicitly to catch problematic comparisons like: int i = -1; unsigned int j = 1; if (i < j) // this is false. long i = -1; unsigned int j = 1; if (i < j) // this is true. C standard for reference: - If either operand is unsigned long the other shall be converted to unsigned long. - Otherwise, if one operand is a long int and the other unsigned int, then if a long int can represent all the values of an unsigned int, the unsigned int shall be converted to a long int; otherwise both operands shall be converted to unsigned long int. - Otherwise, if either operand is long, the other shall be converted to long. - Otherwise, if either operand is unsigned, the other shall be converted to unsigned. Unfortunately clang's -Wsign-compare is very noisy. It complains about (s32)a == (u32)b which is safe and doen't have surprising behavior. This patch fixes some of the issues. It needs a follow up to fix the rest. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20231226191148.48536-2-alexei.starovoitov@gmail.com
Diffstat (limited to 'tools/testing/selftests/bpf/Makefile')
-rw-r--r--tools/testing/selftests/bpf/Makefile1
1 files changed, 1 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index 617ae55c3bb5..fd15017ed3b1 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -383,6 +383,7 @@ CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG),$(CLANG_TARGET_ARCH))
BPF_CFLAGS = -g -Wall -Werror -D__TARGET_ARCH_$(SRCARCH) $(MENDIAN) \
-I$(INCLUDE_DIR) -I$(CURDIR) -I$(APIDIR) \
-I$(abspath $(OUTPUT)/../usr/include)
+# TODO: enable me -Wsign-compare
CLANG_CFLAGS = $(CLANG_SYS_INCLUDES) \
-Wno-compare-distinct-pointer-types