Issue 30013: Compiler warning in Modules/posixmodule.c (original) (raw)

Using gcc-6.3.1 20170306 on Linux 4.10.1, it gave the warning:

gcc -pthread -c -Wno-unused-result -Wsign-compare -g -Og -Wall -Wstrict-prototypes -std=c99 -Wextra -Wno-unused-result -Wno-unused-parameter -Wno-missing-field-initializers -Werror=implicit-function-declaration -I. -I./Include -DPy_BUILD_CORE -o Python/pyctype.o Python/pyctype.c :./Modules/posixmodule.c: In function ‘os_major_impl’: ./Modules/posixmodule.c:8584:13: warning: In the GNU C Library, "major" is defined by <sys/sysmacros.h>. For historical compatibility, it is currently defined by <sys/types.h> as well, but we plan to remove this soon. To use "major", include <sys/sysmacros.h> directly. If you did not intend to use a system-defined macro "major", you should undefine it after including <sys/types.h>. return major(device); ^~~~~~~~~~~~~
./Modules/posixmodule.c: In function ‘os_minor_impl’: ./Modules/posixmodule.c:8601:13: warning: In the GNU C Library, "minor" is defined by <sys/sysmacros.h>. For historical compatibility, it is currently defined by <sys/types.h> as well, but we plan to remove this soon. To use "minor", include <sys/sysmacros.h> directly. If you did not intend to use a system-defined macro "minor", you should undefine it after including <sys/types.h>. return minor(device); ^~~~~~~~~~~~~
./Modules/posixmodule.c: In function ‘os_makedev_impl’: ./Modules/posixmodule.c:8619:13: warning: In the GNU C Library, "makedev" is defined by <sys/sysmacros.h>. For historical compatibility, it is currently defined by <sys/types.h> as well, but we plan to remove this soon. To use "makedev", include <sys/sysmacros.h> directly. If you did not intend to use a system-defined macro "makedev", you should undefine it after including <sys/types.h>. return makedev(major, minor); ^~~~~~~~~~~~~~~~~~~~~

The problem introduce in glibc 2.25, going to deprecate the definition of 'major', 'minor', and 'makedev' by sys/types.h. And the autoconf didn't change the behavior of AC_HEADER_MAJOR, see:

https://lists.gnu.org/archive/html/autoconf/2016-08/msg00014.html

There is a workaround path for this in libvirt, which take from autoconf patch, see:

https://www.redhat.com/archives/libvir-list/2016-September/msg00459.html