Hi,
Here's a few fixes that are part of my effort to get all selftests building cleanly under clang. Plus one that I noticed by inspection.
Changes since v2:
1) Added a sentence to the .PHONY patch, to show that it is removing duplicate code.
2) Added the actual clang warning output to the commit description.
Changes since the first version:
1) Rebased onto Linux 6.10-rc1 2) Added Reviewed-by's.
...and it turns out that all three patches are still required, on -rc1, in order to get a clean clang build.
Enjoy!
thanks, John Hubbard
John Hubbard (3): selftests/futex: don't redefine .PHONY targets (all, clean) selftests/futex: don't pass a const char* to asprintf(3) selftests/futex: pass _GNU_SOURCE without a value to the compiler
tools/testing/selftests/futex/Makefile | 2 -- tools/testing/selftests/futex/functional/Makefile | 2 +- tools/testing/selftests/futex/functional/futex_requeue_pi.c | 2 +- 3 files changed, 2 insertions(+), 4 deletions(-)
base-commit: b050496579632f86ee1ef7e7501906db579f3457
The .PHONY targets "all" and "clean" are both already defined in the file that is included in the very next line:
../lib.mk.
Remove this duplicate code.
Reviewed-by: Davidlohr Bueso dave@stgolabs.net Signed-off-by: John Hubbard jhubbard@nvidia.com --- tools/testing/selftests/futex/Makefile | 2 -- 1 file changed, 2 deletions(-)
diff --git a/tools/testing/selftests/futex/Makefile b/tools/testing/selftests/futex/Makefile index 11e157d7533b..78ab2cd111f6 100644 --- a/tools/testing/selftests/futex/Makefile +++ b/tools/testing/selftests/futex/Makefile @@ -3,8 +3,6 @@ SUBDIRS := functional
TEST_PROGS := run.sh
-.PHONY: all clean - include ../lib.mk
all:
When building with clang, via:
make LLVM=1 -C tools/testing/selftests
...clang issues this warning:
futex_requeue_pi.c:403:17: warning: passing 'const char **' to parameter of type 'char **' discards qualifiers in nested pointer types [-Wincompatible-pointer-types-discards-qualifiers]
This warning fires because test_name is passed into asprintf(3), which then changes it.
Fix this by simply removing the const qualifier. This is a local automatic variable in a very short function, so there is not much need to use the compiler to enforce const-ness at this scope.
[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c...
Fixes: f17d8a87ecb5 ("selftests: fuxex: Report a unique test name per run of futex_requeue_pi") Reviewed-by: Davidlohr Bueso dave@stgolabs.net Signed-off-by: John Hubbard jhubbard@nvidia.com --- tools/testing/selftests/futex/functional/futex_requeue_pi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/futex/functional/futex_requeue_pi.c b/tools/testing/selftests/futex/functional/futex_requeue_pi.c index 7f3ca5c78df1..215c6cb539b4 100644 --- a/tools/testing/selftests/futex/functional/futex_requeue_pi.c +++ b/tools/testing/selftests/futex/functional/futex_requeue_pi.c @@ -360,7 +360,7 @@ int unit_test(int broadcast, long lock, int third_party_owner, long timeout_ns)
int main(int argc, char *argv[]) { - const char *test_name; + char *test_name; int c, ret;
while ((c = getopt(argc, argv, "bchlot:v:")) != -1) {
It's slightly better to set _GNU_SOURCE in the source code, but if one must do it via the compiler invocation, then the best way to do so is this:
$(CC) -D_GNU_SOURCE=
...because otherwise, if this form is used:
$(CC) -D_GNU_SOURCE
...then that leads the compiler to set a value, as if you had passed in:
$(CC) -D_GNU_SOURCE=1
That, in turn, leads to warnings under both gcc and clang, like this:
futex_requeue_pi.c:20: warning: "_GNU_SOURCE" redefined
Fix this by using the "-D_GNU_SOURCE=" form.
Reviewed-by: Edward Liaw edliaw@google.com Reviewed-by: Davidlohr Bueso dave@stgolabs.net Signed-off-by: John Hubbard jhubbard@nvidia.com --- tools/testing/selftests/futex/functional/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/futex/functional/Makefile b/tools/testing/selftests/futex/functional/Makefile index a392d0917b4e..994fa3468f17 100644 --- a/tools/testing/selftests/futex/functional/Makefile +++ b/tools/testing/selftests/futex/functional/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 INCLUDES := -I../include -I../../ $(KHDR_INCLUDES) -CFLAGS := $(CFLAGS) -g -O2 -Wall -D_GNU_SOURCE -pthread $(INCLUDES) $(KHDR_INCLUDES) +CFLAGS := $(CFLAGS) -g -O2 -Wall -D_GNU_SOURCE= -pthread $(INCLUDES) $(KHDR_INCLUDES) LDLIBS := -lpthread -lrt
LOCAL_HDRS := \
On 5/31/24 14:07, John Hubbard wrote:
Hi,
Here's a few fixes that are part of my effort to get all selftests building cleanly under clang. Plus one that I noticed by inspection.
Changes since v2:
Added a sentence to the .PHONY patch, to show that it is removing duplicate code.
Added the actual clang warning output to the commit description.
Changes since the first version:
- Rebased onto Linux 6.10-rc1
- Added Reviewed-by's.
...and it turns out that all three patches are still required, on -rc1, in order to get a clean clang build.
Enjoy!
thanks, John Hubbard
John Hubbard (3): selftests/futex: don't redefine .PHONY targets (all, clean) selftests/futex: don't pass a const char* to asprintf(3) selftests/futex: pass _GNU_SOURCE without a value to the compiler
tools/testing/selftests/futex/Makefile | 2 -- tools/testing/selftests/futex/functional/Makefile | 2 +- tools/testing/selftests/futex/functional/futex_requeue_pi.c | 2 +- 3 files changed, 2 insertions(+), 4 deletions(-)
base-commit: b050496579632f86ee1ef7e7501906db579f3457
Thank you - applied to linux-kselftest fixes branch for next rc.
thanks, -- Shuah
linux-kselftest-mirror@lists.linaro.org
-
John Hubbard -
Shuah Khan