diff mbox series

[bpf-next,v3,2/3] bpftool: Prevent setting duplicate _GNU_SOURCE in Makefile

Message ID acec3108b62d4df1436cda777e58e93e033ac7a7.1730449390.git.vmalik@redhat.com (mailing list archive)
State Accepted
Commit 0513eeee86d67930f3567e450357d8db1cfb4f16
Delegated to: BPF
Headers show
Series selftests/bpf: Improve building with extra | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-37 success Logs for x86_64-llvm-18 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-38 success Logs for x86_64-llvm-18 / test (test_progs_cpuv4, false, 360) / test_progs_cpuv4 on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-39 success Logs for x86_64-llvm-18 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-18
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 5 this patch: 5
netdev/build_tools success Errors and warnings before: 0 (+0) this patch: 0 (+0)
netdev/cc_maintainers warning 1 maintainers not CCed: llvm@lists.linux.dev
netdev/build_clang success Errors and warnings before: 4 this patch: 4
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 12 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-VM_Test-4 success Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-6 success Logs for aarch64-gcc / test (test_maps, false, 360) / test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-11 success Logs for s390x-gcc / build / build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-33 success Logs for x86_64-llvm-17 / veristat
bpf/vmtest-bpf-next-VM_Test-34 success Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-35 success Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18-O2
bpf/vmtest-bpf-next-VM_Test-41 success Logs for x86_64-llvm-18 / veristat
bpf/vmtest-bpf-next-VM_Test-19 success Logs for x86_64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-18 success Logs for x86_64-gcc / build / build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-16 success Logs for s390x-gcc / veristat
bpf/vmtest-bpf-next-VM_Test-27 success Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-28 success Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17-O2
bpf/vmtest-bpf-next-VM_Test-17 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-14 success Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-15 success Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-13 success Logs for s390x-gcc / test (test_progs, false, 360) / test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for x86_64-gcc / test (test_maps, false, 360) / test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-32 success Logs for x86_64-llvm-17 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-21 success Logs for x86_64-gcc / test (test_progs, false, 360) / test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-29 success Logs for x86_64-llvm-17 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-22 success Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-31 success Logs for x86_64-llvm-17 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-24 success Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-25 success Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 success Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for x86_64-gcc / veristat / veristat on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-30 success Logs for x86_64-llvm-17 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-36 success Logs for x86_64-llvm-18 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-40 success Logs for x86_64-llvm-18 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-18
bpf/vmtest-bpf-next-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Unittests
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Validate matrix.py
bpf/vmtest-bpf-next-VM_Test-5 success Logs for aarch64-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-7 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-next-VM_Test-8 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-10 success Logs for x86_64-gcc / build-release

Commit Message

Viktor Malik Nov. 1, 2024, 8:27 a.m. UTC 
When building selftests with CFLAGS set via env variable, the value of
CFLAGS is propagated into bpftool Makefile (called from selftests
Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
times - once from selftests Makefile (by including lib.mk) and once from
bpftool Makefile (by calling `llvm-config --cflags`):

    $ CFLAGS="" make -C tools/testing/selftests/bpf
    [...]
    CC      /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
    <command-line>: error: "_GNU_SOURCE" redefined [-Werror]
    <command-line>: note: this is the location of the previous definition
    cc1: all warnings being treated as errors
    [...]

Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
bpftool Makefile to prevent this error.

Signed-off-by: Viktor Malik <vmalik@redhat.com>
Acked-by: Quentin Monnet <qmo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/bpf/bpftool/Makefile | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Toke Høiland-Jørgensen Nov. 4, 2024, 2:05 p.m. UTC | #1 
Viktor Malik <vmalik@redhat.com> writes:

> When building selftests with CFLAGS set via env variable, the value of
> CFLAGS is propagated into bpftool Makefile (called from selftests
> Makefile). This makes the compilation fail as _GNU_SOURCE is defined two
> times - once from selftests Makefile (by including lib.mk) and once from
> bpftool Makefile (by calling `llvm-config --cflags`):
>
>     $ CFLAGS="" make -C tools/testing/selftests/bpf
>     [...]
>     CC      /bpf-next/tools/testing/selftests/bpf/tools/build/bpftool/btf.o
>     <command-line>: error: "_GNU_SOURCE" redefined [-Werror]
>     <command-line>: note: this is the location of the previous definition
>     cc1: all warnings being treated as errors
>     [...]
>
> Filter out -D_GNU_SOURCE from the result of `llvm-config --cflags` in
> bpftool Makefile to prevent this error.
>
> Signed-off-by: Viktor Malik <vmalik@redhat.com>
> Acked-by: Quentin Monnet <qmo@kernel.org>
> Acked-by: Jiri Olsa <jolsa@kernel.org>

Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
diff mbox series

Patch

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index ba927379eb20..a4263dfb5e03 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -147,7 +147,11 @@  ifeq ($(feature-llvm),1)
   # If LLVM is available, use it for JIT disassembly
   CFLAGS  += -DHAVE_LLVM_SUPPORT
   LLVM_CONFIG_LIB_COMPONENTS := mcdisassembler all-targets
-  CFLAGS  += $(shell $(LLVM_CONFIG) --cflags)
+  # llvm-config always adds -D_GNU_SOURCE, however, it may already be in CFLAGS
+  # (e.g. when bpftool build is called from selftests build as selftests
+  # Makefile includes lib.mk which sets -D_GNU_SOURCE) which would cause
+  # compilation error due to redefinition. Let's filter it out here.
+  CFLAGS  += $(filter-out -D_GNU_SOURCE,$(shell $(LLVM_CONFIG) --cflags))
   LIBS    += $(shell $(LLVM_CONFIG) --libs $(LLVM_CONFIG_LIB_COMPONENTS))
   ifeq ($(shell $(LLVM_CONFIG) --shared-mode),static)
     LIBS += $(shell $(LLVM_CONFIG) --system-libs $(LLVM_CONFIG_LIB_COMPONENTS))