Use the GL_CFLAG_GNULIB_WARNINGS for most AC_LIBOBJ compilation units

[Bruno Haible]

On 2022-01-05, I added a GL_CFLAG_GNULIB_WARNINGS and enabled it
  - in lib/Makefile.am, for the compilation units that are part of
    libgnu.a,
  - in tests/Makefile.am, for all compilation units.

However, it turns out that in lib/Makefile.am it is only activated
for compilation units that the module description declares through

  lib_SOURCES += foobar.c

Whereas when we use

  AC_LIBOBJ([foobar])

then foobar.o appears in the variable gl_LIBOBJS, and the Automake
statement

  libgnu_a_LIBADD = $(gl_LIBOBJS)

has the effect that
  - the compilation unit foobar.c gets compiled *without* reference to
    libgnu_a_CFLAGS, and thus without the GL_CFLAG_GNULIB_WARNINGS,
  - the object file becomes part of the library only at link time.

This is not what we want. I don't think it's an Automake bug, because
this way of processing the *_LIBADD makes sense. (E.g. there may be
two libraries, and the same .o files getting added to both. They should
not be compiled twice in this situation.)

Recall also that with Automake, we can assign CFLAGS on a per-library
or per-program basis, not per object file. See
<https://www.gnu.org/software/automake/manual/html_node/Program-and-Library-Variables.html>.

The solution, in order to make use of the GL_CFLAG_GNULIB_WARNINGS, is
to eliminate the AC_LIBOBJ([foobar]) invocation and instead use a
lib_SOURCES augmentation.

This patch implements it for ca. 90% of the AC_LIBOBJ invocations.

For the moment, the following are left alone:
  - The *printf* modules, because they are complex to refactor,
  - AC_LIBOBJ invocations of the same source file, triggered by 2 or more
    modules. Recall that AC_LIBOBJ has a built-in "eliminate duplicates"
    mechanism, whereas lib_SOURCES augmentation doesn't. (In other words,
    when you do
      lib_SOURCES += foobar.c
    then libgnu.a will contain foobar.o twice.)


2022-01-09  Bruno Haible  <bruno@clisp.org>

        Use the GL_CFLAG_GNULIB_WARNINGS for most AC_LIBOBJ compilation units.
        * modules/_Exit (configure.ac): Define an Automake conditional. Remove
        the AC_LIBOBJ invocation.
        (Makefile.am): Augment lib_SOURCES, guarded by that Automake
        conditional.
        * modules/accept: Likewise.
        * modules/access: Likewise.
        * modules/acosf: Likewise.
        * modules/acosl: Likewise.
        * modules/aligned_alloc: Likewise.
        * modules/alphasort: Likewise.
        * modules/argz: Likewise.
        * modules/asinf: Likewise.
        * modules/asinl: Likewise.
        * modules/atan2f: Likewise.
        * modules/atanf: Likewise.
        * modules/atanl: Likewise.
        * modules/atexit: Likewise.
        * modules/atoll: Likewise.
        * modules/bind: Likewise.
        * modules/btowc: Likewise.
        * modules/c32rtomb: Likewise.
        * modules/canonicalize-lgpl: Likewise.
        * modules/cbrt: Likewise.
        * modules/cbrtf: Likewise.
        * modules/cbrtl: Likewise.
        * modules/ceil: Likewise.
        * modules/ceilf: Likewise.
        * modules/ceill: Likewise.
        * modules/chdir-long: Likewise.
        * modules/chown: Likewise.
        * modules/close: Likewise.
        * modules/closedir: Likewise.
        * modules/cnd: Likewise.
        * modules/connect: Likewise.
        * modules/copy-file-range: Likewise.
        * modules/copysign: Likewise.
        * modules/copysignf: Likewise.
        * modules/copysignl: Likewise.
        * modules/cosf: Likewise.
        * modules/coshf: Likewise.
        * modules/cosl: Likewise.
        * modules/creat: Likewise.
        * modules/crypto/gc: Likewise.
        * modules/ctime: Likewise.
        * modules/dirfd: Likewise.
        * modules/dup: Likewise.
        * modules/dup2: Likewise.
        * modules/duplocale: Likewise.
        * modules/error: Likewise.
        * modules/euidaccess: Likewise.
        * modules/execinfo: Likewise.
        * modules/execl: Likewise.
        * modules/execle: Likewise.
        * modules/execlp: Likewise.
        * modules/execv: Likewise.
        * modules/execve: Likewise.
        * modules/execvp: Likewise.
        * modules/execvpe: Likewise.
        * modules/exp2: Likewise.
        * modules/exp2f: Likewise.
        * modules/exp2l: Likewise.
        * modules/expf: Likewise.
        * modules/expl: Likewise.
        * modules/explicit_bzero: Likewise.
        * modules/expm1: Likewise.
        * modules/expm1f: Likewise.
        * modules/expm1l: Likewise.
        * modules/fabsf: Likewise.
        * modules/fabsl: Likewise.
        * modules/faccessat: Likewise.
        * modules/fchdir: Likewise.
        * modules/fchmodat: Likewise.
        * modules/fchownat: Likewise.
        * modules/fclose: Likewise.
        * modules/fcntl: Likewise.
        * modules/fdatasync: Likewise.
        * modules/fdopen: Likewise.
        * modules/fdopendir: Likewise.
        * modules/fflush: Likewise.
        * modules/ffs: Likewise.
        * modules/ffsl: Likewise.
        * modules/ffsll: Likewise.
        * modules/fileblocks: Likewise.
        * modules/float: Likewise.
        * modules/flock: Likewise.
        * modules/floor: Likewise.
        * modules/floorf: Likewise.
        * modules/floorl: Likewise.
        * modules/fma: Likewise.
        * modules/fmaf: Likewise.
        * modules/fmal: Likewise.
        * modules/fmod: Likewise.
        * modules/fmodf: Likewise.
        * modules/fmodl: Likewise.
        * modules/forkpty: Likewise.
        * modules/fpending: Likewise.
        * modules/fpurge: Likewise.
        * modules/freadable: Likewise.
        * modules/freadahead: Likewise.
        * modules/freadptr: Likewise.
        * modules/free-posix: Likewise.
        * modules/freopen: Likewise.
        * modules/frexpf: Likewise.
        * modules/fseek: Likewise.
        * modules/fseeko: Likewise.
        * modules/fseterr: Likewise.
        * modules/fstat: Likewise.
        * modules/fstatat: Likewise.
        * modules/fsusage: Likewise.
        * modules/fsync: Likewise.
        * modules/ftell: Likewise.
        * modules/ftello: Likewise.
        * modules/ftruncate: Likewise.
        * modules/fts: Likewise.
        * modules/futimens: Likewise.
        * modules/fwritable: Likewise.
        * modules/fwriting: Likewise.
        * modules/getaddrinfo: Likewise.
        * modules/getcwd: Likewise.
        * modules/getcwd-lgpl: Likewise.
        * modules/getdelim: Likewise.
        * modules/getdomainname: Likewise.
        * modules/getdtablesize: Likewise.
        * modules/getentropy: Likewise.
        * modules/getgroups: Likewise.
        * modules/gethostname: Likewise.
        * modules/getline: Likewise.
        * modules/getloadavg: Likewise.
        * modules/getlogin: Likewise.
        * modules/getlogin_r: Likewise.
        * modules/getopt-posix: Likewise.
        * modules/getpagesize: Likewise.
        * modules/getpeername: Likewise.
        * modules/getrandom: Likewise.
        * modules/getrusage: Likewise.
        * modules/getsockname: Likewise.
        * modules/getsockopt: Likewise.
        * modules/getsubopt: Likewise.
        * modules/gettimeofday: Likewise.
        * modules/getumask: Likewise.
        * modules/getusershell: Likewise.
        * modules/glob: Likewise.
        * modules/grantpt: Likewise.
        * modules/group-member: Likewise.
        * modules/hypot: Likewise.
        * modules/hypotf: Likewise.
        * modules/hypotl: Likewise.
        * modules/iconv_open: Likewise.
        * modules/ilogb: Likewise.
        * modules/ilogbf: Likewise.
        * modules/ilogbl: Likewise.
        * modules/imaxabs: Likewise.
        * modules/imaxdiv: Likewise.
        * modules/inet_ntop: Likewise.
        * modules/inet_pton: Likewise.
        * modules/ioctl: Likewise.
        * modules/isapipe: Likewise.
        * modules/isatty: Likewise.
        * modules/isblank: Likewise.
        * modules/isfinite: Likewise.
        * modules/isinf: Likewise.
        * modules/iswblank: Likewise.
        * modules/iswctype: Likewise.
        * modules/iswdigit: Likewise.
        * modules/iswxdigit: Likewise.
        * modules/lchmod: Likewise.
        * modules/lchown: Likewise.
        * modules/ldexpf: Likewise.
        * modules/ldexpl: Likewise.
        * modules/libgmp: Likewise.
        * modules/link: Likewise.
        * modules/linkat: Likewise.
        * modules/listen: Likewise.
        * modules/localeconv: Likewise.
        * modules/localtime: Likewise.
        * modules/log: Likewise.
        * modules/log10: Likewise.
        * modules/log10f: Likewise.
        * modules/log10l: Likewise.
        * modules/log1p: Likewise.
        * modules/log1pf: Likewise.
        * modules/log1pl: Likewise.
        * modules/log2: Likewise.
        * modules/log2f: Likewise.
        * modules/log2l: Likewise.
        * modules/logb: Likewise.
        * modules/logbf: Likewise.
        * modules/logbl: Likewise.
        * modules/logf: Likewise.
        * modules/login_tty: Likewise.
        * modules/logl: Likewise.
        * modules/lseek: Likewise.
        * modules/lstat: Likewise.
        * modules/mbrlen: Likewise.
        * modules/mbrtoc32: Likewise.
        * modules/mbrtowc: Likewise.
        * modules/mbsinit: Likewise.
        * modules/mbsnrtowcs: Likewise.
        * modules/mbsrtowcs: Likewise.
        * modules/mbtowc: Likewise.
        * modules/memalign: Likewise.
        * modules/memchr: Likewise.
        * modules/memcmp: Likewise.
        * modules/memcpy: Likewise.
        * modules/memmove: Likewise.
        * modules/mempcpy: Likewise.
        * modules/memrchr: Likewise.
        * modules/memset: Likewise.
        * modules/mkdir: Likewise.
        * modules/mkdirat: Likewise.
        * modules/mkdtemp: Likewise.
        * modules/mkfifo: Likewise.
        * modules/mkfifoat: Likewise.
        * modules/mknod: Likewise.
        * modules/mkostemp: Likewise.
        * modules/mkostemps: Likewise.
        * modules/mkstemp: Likewise.
        * modules/mkstemps: Likewise.
        * modules/modf: Likewise.
        * modules/modff: Likewise.
        * modules/modfl: Likewise.
        * modules/mountlist: Likewise.
        * modules/msvc-inval: Likewise.
        * modules/msvc-nothrow: Likewise.
        * modules/mtx: Likewise.
        * modules/nanosleep: Likewise.
        * modules/nl_langinfo: Likewise.
        * modules/obstack: Likewise.
        * modules/open: Likewise.
        * modules/openat: Likewise.
        * modules/opendir: Likewise.
        * modules/openpty: Likewise.
        * modules/pclose: Likewise.
        * modules/perror: Likewise.
        * modules/pipe-posix: Likewise.
        * modules/poll: Likewise.
        * modules/popen: Likewise.
        * modules/posix_memalign: Likewise.
        * modules/posix_openpt: Likewise.
        * modules/posix_spawn: Likewise.
        * modules/posix_spawn-internal: Likewise.
        * modules/posix_spawn_file_actions_addchdir: Likewise.
        * modules/posix_spawn_file_actions_addclose: Likewise.
        * modules/posix_spawn_file_actions_adddup2: Likewise.
        * modules/posix_spawn_file_actions_addfchdir: Likewise.
        * modules/posix_spawn_file_actions_addopen: Likewise.
        * modules/posix_spawn_file_actions_destroy: Likewise.
        * modules/posix_spawn_file_actions_init: Likewise.
        * modules/posix_spawnattr_destroy: Likewise.
        * modules/posix_spawnattr_getflags: Likewise.
        * modules/posix_spawnattr_getpgroup: Likewise.
        * modules/posix_spawnattr_getschedparam: Likewise.
        * modules/posix_spawnattr_getschedpolicy: Likewise.
        * modules/posix_spawnattr_getsigdefault: Likewise.
        * modules/posix_spawnattr_getsigmask: Likewise.
        * modules/posix_spawnattr_init: Likewise.
        * modules/posix_spawnattr_setflags: Likewise.
        * modules/posix_spawnattr_setpgroup: Likewise.
        * modules/posix_spawnattr_setschedparam: Likewise.
        * modules/posix_spawnattr_setschedpolicy: Likewise.
        * modules/posix_spawnattr_setsigdefault: Likewise.
        * modules/posix_spawnattr_setsigmask: Likewise.
        * modules/posix_spawnp: Likewise.
        * modules/powf: Likewise.
        * modules/pread: Likewise.
        * modules/pselect: Likewise.
        * modules/pthread-cond: Likewise.
        * modules/pthread-mutex: Likewise.
        * modules/pthread-once: Likewise.
        * modules/pthread-rwlock: Likewise.
        * modules/pthread-spin: Likewise.
        * modules/pthread-thread: Likewise.
        * modules/pthread-tss: Likewise.
        * modules/pthread_mutex_timedlock: Likewise.
        * modules/pthread_sigmask: Likewise.
        * modules/ptsname: Likewise.
        * modules/ptsname_r: Likewise.
        * modules/putenv: Likewise.
        * modules/pwrite: Likewise.
        * modules/qsort_r: Likewise.
        * modules/raise: Likewise.
        * modules/random: Likewise.
        * modules/random_r: Likewise.
        * modules/rawmemchr: Likewise.
        * modules/read: Likewise.
        * modules/readdir: Likewise.
        * modules/readline: Likewise.
        * modules/readlink: Likewise.
        * modules/readlinkat: Likewise.
        * modules/readutmp: Likewise.
        * modules/reallocarray: Likewise.
        * modules/recv: Likewise.
        * modules/recvfrom: Likewise.
        * modules/regex: Likewise.
        * modules/relocatable-prog: Likewise.
        * modules/remainder: Likewise.
        * modules/remainderf: Likewise.
        * modules/remainderl: Likewise.
        * modules/remove: Likewise.
        * modules/rename: Likewise.
        * modules/renameat: Likewise.
        * modules/rewinddir: Likewise.
        * modules/rint: Likewise.
        * modules/rintf: Likewise.
        * modules/rintl: Likewise.
        * modules/rmdir: Likewise.
        * modules/round: Likewise.
        * modules/roundf: Likewise.
        * modules/roundl: Likewise.
        * modules/rpmatch: Likewise.
        * modules/scandir: Likewise.
        * modules/sched_yield: Likewise.
        * modules/secure_getenv: Likewise.
        * modules/select: Likewise.
        * modules/selinux-h: Likewise.
        * modules/send: Likewise.
        * modules/sendto: Likewise.
        * modules/setenv: Likewise.
        * modules/sethostname: Likewise.
        * modules/setlocale: Likewise.
        * modules/setlocale-null: Likewise.
        * modules/setsockopt: Likewise.
        * modules/shutdown: Likewise.
        * modules/sig2str: Likewise.
        * modules/sigabbrev_np: Likewise.
        * modules/sigaction: Likewise.
        * modules/sigdescr_np: Likewise.
        * modules/signbit: Likewise.
        * modules/sigprocmask: Likewise.
        * modules/sinf: Likewise.
        * modules/sinhf: Likewise.
        * modules/sinl: Likewise.
        * modules/sleep: Likewise.
        * modules/socket: Likewise.
        * modules/spawn-pipe: Likewise.
        * modules/sqrtf: Likewise.
        * modules/sqrtl: Likewise.
        * modules/stat: Likewise.
        * modules/stdio: Likewise.
        * modules/stpcpy: Likewise.
        * modules/stpncpy: Likewise.
        * modules/strcase: Likewise.
        * modules/strchrnul: Likewise.
        * modules/strcspn: Likewise.
        * modules/strdup-posix: Likewise.
        * modules/strerror: Likewise.
        * modules/strerror-override: Likewise.
        * modules/strerrorname_np: Likewise.
        * modules/strfmon_l: Likewise.
        * modules/strftime-fixes: Likewise.
        * modules/strncat: Likewise.
        * modules/strndup: Likewise.
        * modules/strnlen: Likewise.
        * modules/strpbrk: Likewise.
        * modules/strptime: Likewise.
        * modules/strsep: Likewise.
        * modules/strsignal: Likewise.
        * modules/strtod: Likewise.
        * modules/strtoimax: Likewise.
        * modules/strtok_r: Likewise.
        * modules/strtol: Likewise.
        * modules/strtold: Likewise.
        * modules/strtoll: Likewise.
        * modules/strtoul: Likewise.
        * modules/strtoull: Likewise.
        * modules/strtoumax: Likewise.
        * modules/strverscmp: Likewise.
        * modules/symlink: Likewise.
        * modules/symlinkat: Likewise.
        * modules/tanf: Likewise.
        * modules/tanhf: Likewise.
        * modules/tanl: Likewise.
        * modules/tcgetsid: Likewise.
        * modules/thrd: Likewise.
        * modules/time_r: Likewise.
        * modules/time_rz: Likewise.
        * modules/timegm: Likewise.
        * modules/times: Likewise.
        * modules/timespec_get: Likewise.
        * modules/timespec_getres: Likewise.
        * modules/tmpfile: Likewise.
        * modules/towctrans: Likewise.
        * modules/trunc: Likewise.
        * modules/truncate: Likewise.
        * modules/truncf: Likewise.
        * modules/truncl: Likewise.
        * modules/tsearch: Likewise.
        * modules/tss: Likewise.
        * modules/ttyname_r: Likewise.
        * modules/tzset: Likewise.
        * modules/uname: Likewise.
        * modules/unlink: Likewise.
        * modules/unlinkat: Likewise.
        * modules/unlockpt: Likewise.
        * modules/unsetenv: Likewise.
        * modules/usleep: Likewise.
        * modules/utime: Likewise.
        * modules/utimensat: Likewise.
        * modules/waitpid: Likewise.
        * modules/wcpcpy: Likewise.
        * modules/wcpncpy: Likewise.
        * modules/wcrtomb: Likewise.
        * modules/wcscasecmp: Likewise.
        * modules/wcscat: Likewise.
        * modules/wcschr: Likewise.
        * modules/wcscmp: Likewise.
        * modules/wcscoll: Likewise.
        * modules/wcscpy: Likewise.
        * modules/wcscspn: Likewise.
        * modules/wcsdup: Likewise.
        * modules/wcsftime: Likewise.
        * modules/wcslen: Likewise.
        * modules/wcsncasecmp: Likewise.
        * modules/wcsncat: Likewise.
        * modules/wcsncmp: Likewise.
        * modules/wcsncpy: Likewise.
        * modules/wcsnlen: Likewise.
        * modules/wcsnrtombs: Likewise.
        * modules/wcspbrk: Likewise.
        * modules/wcsrchr: Likewise.
        * modules/wcsrtombs: Likewise.
        * modules/wcsspn: Likewise.
        * modules/wcsstr: Likewise.
        * modules/wcstok: Likewise.
        * modules/wcswidth: Likewise.
        * modules/wcsxfrm: Likewise.
        * modules/wctob: Likewise.
        * modules/wctomb: Likewise.
        * modules/wctrans: Likewise.
        * modules/wctype: Likewise.
        * modules/wcwidth: Likewise.
        * modules/windows-cond: Likewise.
        * modules/windows-mutex: Likewise.
        * modules/windows-once: Likewise.
        * modules/windows-recmutex: Likewise.
        * modules/windows-rwlock: Likewise.
        * modules/windows-spawn: Likewise.
        * modules/windows-spin: Likewise.
        * modules/windows-thread: Likewise.
        * modules/windows-timedmutex: Likewise.
        * modules/windows-timedrecmutex: Likewise.
        * modules/windows-timedrwlock: Likewise.
        * modules/windows-tls: Likewise.
        * modules/wmemchr: Likewise.
        * modules/wmemcmp: Likewise.
        * modules/wmemcpy: Likewise.
        * modules/wmemmove: Likewise.
        * modules/wmempcpy: Likewise.
        * modules/wmemset: Likewise.
        * modules/write: Likewise.

0001-Use-the-GL_CFLAG_GNULIB_WARNINGS-for-most-AC_LIBOBJ-.patch.gz
Description: application/gzip