| Message ID | 20240529022938.129624-4-jhubbard@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | cb708ab9f584f159798b60853edcf0c8b67ce295 |
| Headers | show |
| Series | selftests/futex: clang-inspired fixes | expand |
On 5/28/24 20:29, John Hubbard wrote: > 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 := \ This looks fine. Applied now to linux-kselftest fixes branch thanks, -- Shuah
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 := \
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(-)