ISO C2X has made some changes to the handling of feature test macros
related to features from the floating-point TSes, and to exactly what
such features are present in what headers, that require corresponding
changes in glibc.
* For the few features that were controlled by
__STDC_WANT_IEC_60559_BFP_EXT__ (and the corresponding DFP macro) in
C2X, there is now instead a new feature test macro
__STDC_WANT_IEC_60559_EXT__ covering both binary and decimal FP.
This controls CR_DECIMAL_DIG in <float.h> (provided by GCC; I
implemented support for the new feature test macro for GCC 11) and
the totalorder and payload functions in <math.h>. C2X no longer
says anything about __STDC_WANT_IEC_60559_BFP_EXT__ (so it's
appropriate for that macro to continue to enable exactly the
features from TS 18661-1).
* The SNAN macros for each floating-point type have moved to <float.h>
(and been renamed in the process). Thus, the copies in <math.h>
should only be defined for __STDC_WANT_IEC_60559_BFP_EXT__, not for
C2X.
* The fmaxmag and fminmag functions have been removed (replaced by new
functions for the new min/max operations in IEEE 754-2019). Thus
those should also only be declared for
__STDC_WANT_IEC_60559_BFP_EXT__.
* The _FloatN / _FloatNx handling for the last two points in glibc is
trickier, since __STDC_WANT_IEC_60559_TYPES_EXT__ is still in C2X
(the integration of TS 18661-3 as an Annex, that is, which hasn't
yet been merged into the C standard git repository but has been
accepted by WG14), so C2X with that macro should not declare some
things that are declared for older standards with that macro. The
approach taken here is to provide the declarations (when
__STDC_WANT_IEC_60559_TYPES_EXT__ is enabled) only when (defined
__USE_GNU || !__GLIBC_USE (ISOC2X)), so if C2X features are enabled
then those declarations (that are only in TS 18661-3 and not in C2X)
will only be provided if _GNU_SOURCE is defined as well. Thus
_GNU_SOURCE remains a superset of the TS features as well as of C2X.
Some other somewhat related changes in C2X are not addressed here.
There's an open proposal not to include the fmin and fmax functions
for the _FloatN / _FloatNx types, given the new min/max operations,
which could be handled like the previous point if adopted. And the
fromfp functions have been changed to return a result in floating type
rather than intmax_t / uintmax_t; my inclination there is to treat
that like that change of totalorder type (new symbol versions etc. for
the ABI change; old versions become compat symbols and are no longer
supported as an API).
Tested for x86_64 and x86.
Add _SC_MINSIGSTKSZ for the minimum signal stack size derived from
AT_MINSIGSTKSZ, which is the minimum number of bytes of free stack
space required in order to gurantee successful, non-nested handling
of a single signal whose handler is an empty function, and _SC_SIGSTKSZ
which is the suggested minimum number of bytes of stack space required
for a signal stack.
If AT_MINSIGSTKSZ isn't available, sysconf (_SC_MINSIGSTKSZ) returns
MINSIGSTKSZ. On Linux/x86 with XSAVE, the signal frame used by kernel
is composed of the following areas and laid out as:
------------------------------
| alignment padding |
------------------------------
| xsave buffer |
------------------------------
| fsave header (32-bit only) |
------------------------------
| siginfo + ucontext |
------------------------------
Compute AT_MINSIGSTKSZ value as size of xsave buffer + size of fsave
header (32-bit only) + size of siginfo and ucontext + alignment padding.
If _SC_SIGSTKSZ_SOURCE or _GNU_SOURCE are defined, MINSIGSTKSZ and SIGSTKSZ
are redefined as
/* Default stack size for a signal handler: sysconf (SC_SIGSTKSZ). */
# undef SIGSTKSZ
# define SIGSTKSZ sysconf (_SC_SIGSTKSZ)
/* Minimum stack size for a signal handler: SIGSTKSZ. */
# undef MINSIGSTKSZ
# define MINSIGSTKSZ SIGSTKSZ
Compilation will fail if the source assumes constant MINSIGSTKSZ or
SIGSTKSZ.
The reason for not simply increasing the kernel's MINSIGSTKSZ #define
(apart from the fact that it is rarely used, due to glibc's shadowing
definitions) was that userspace binaries will have baked in the old
value of the constant and may be making assumptions about it.
For example, the type (char [MINSIGSTKSZ]) changes if this #define
changes. This could be a problem if an newly built library tries to
memcpy() or dump such an object defined by and old binary.
Bounds-checking and the stack sizes passed to things like sigaltstack()
and makecontext() could similarly go wrong.
I used these shell commands:
../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")
and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
The new __proc_waitid RPC now expects WEXITED to be passed, allowing to
properly implement waitid, and thus define the missing W* macros
(according to FreeBSD values).
SA_SIGINFO is actually just another way of expressing what we were
already passing over with struct sigcontext. This just introduces the
SIGINFO interface and fixes the posix values when that interface is
requested by the application.
The symbol is deprecated by strerror since its usage imposes some issues
such as copy relocations.
Its internal name is also changed to _sys_errlist_internal to avoid
static linking usage. The compat code is also refactored by removing
the over enginered errlist-compat.c generation from manual entried and
extra comment token in linker script file. It disantangle the code
generation from manual and simplify both Linux and Hurd compat code.
The definitions from errlist.c are moved to errlist.h and a new test
is added to avoid a new errno entry without an associated one in manual.
Checked on x86_64-linux-gnu and i686-linux-gnu. I also run a check-abi
on all affected platforms.
Tested-by: Carlos O'Donell <carlos@redhat.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It refactor how signals are defined by each architecture. Instead of
include a generic header (bits/signum-generic.h) and undef non-default
values in an arch specific header (bits/signum.h) the new scheme uses a
common definition (bits/signum-generic.h) and each architectures add
its specific definitions on a new header (bits/signum-arch.h).
For Linux it requires copy some system default definitions to alpha,
hppa, and sparc. They are historical values and newer ports uses
the generic Linux signum-arch.h.
For Hurd the BSD signum is removed and moved to a new header (it is
used currently only on Hurd).
Checked on a build against all affected ABIs.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
Improve the commentary to aid future developers who will stumble
upon this novel, yet not always perfect, mechanism to support
alternative formats for long double.
Likewise, rename __LONG_DOUBLE_USES_FLOAT128 to
__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI now that development work
has settled down. The command used was
git grep -l __LONG_DOUBLE_USES_FLOAT128 ':!./ChangeLog*' | \
xargs sed -i 's/__LONG_DOUBLE_USES_FLOAT128/__LDOUBLE_REDIRECTS_TO_FLOAT128_ABI/g'
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
On y2038 safe 32-bit systems the Linux kernel expects itimerval
and rusage to use a 32-bit time_t, even though the other time_t's
are 64-bit. There are currently no plans to make 64-bit time_t versions
of these structs.
There are also other occurrences where the time passed to the kernel via
timeval doesn't match the wordsize.
To handle these cases let's define a new macro
__KERNEL_OLD_TIMEVAL_MATCHES_TIMEVAL64. This macro specifies if the
kernel's old_timeval matches the new timeval64. This should be 1 for
64-bit architectures except for Alpha's osf syscalls. The define should
be 0 for 32-bit architectures and Alpha's osf syscalls.
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Similar to string2.h (18b10de7ce) and string3.h (09a596cc2c) this
patch removes the fenvinline.h on all architectures. Currently
only powerpc implements some optimizations. This kind of optimization
is better implemented by the compiler (which handles the architecture
ISA transparently).
Also, for the specific optimized powerpc implementation the code is
becoming convoluted and these micro-optimization are hardly wildly
used, even more being a possible hotspot in realword cases
(non-default rounding are used only on specific cases and exception
handling are done most likely only on errors path). Only x86
implements similar optimization (on fenv.h) also indicates that
these should no be on libc.
The math/test-fenv already covers all math/test-fenvinline tests,
so it is safe to remove it.
The powerpc fegetround optimization is moved to internal
fenv_libc.h.
The BZ#94193 [1] the corresponding GCC bug for adding replacements
for these on powerpc.
Checked on x86_64-linux-gnu and powerpc64le-linux-gnu.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94193
The __suseconds64_t type is supposed to be the 64 bit type across all
architectures.
It would be mostly used internally in the glibc - however, when passed to
Linux kernel (very unlikely), if necessary, it shall be converted to 32
bit type (i.e. __suseconds_t)
Build tests:
./src/scripts/build-many-glibcs.py glibcs
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
On platforms where long double has IEEE binary128 format as a third
option (initially, only powerpc64le), many exported functions are
redirected to their __*ieee128 equivalents. This redirection is
provided by installed headers such as stdio-ldbl.h, and is supposed to
work correctly with user code.
However, during the build of glibc, similar redirections are employed,
in internal headers, such as include/stdio.h, in order to avoid extra
PLT entries. These redirections conflict with the redirections to
__*ieee128, and must be avoided during the build. This patch protects
the second redirections with a test for __LONG_DOUBLE_USES_FLOAT128, a
new macro that is defined to 1 when functions that deal with long double
typed values reuses the _Float128 implementation (this is currently only
true for powerpc64le).
Tested for powerpc64le, x86_64, and with build-many-glibcs.py.
Co-authored-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Add a new macro __STATFS_MATCHES_STATFS64 that specifies if fsblkcnt_t
matches fsblkcnt64_t and if fsfilcnt_t matches fsfilcnt64_t.
As we don't have the padding we also need to update the overflow checker
to not access the undefined members.
Commit 7532837d7b ("The
-Wstringop-truncation option new in GCC 8 detects common misuses")
added __attribute_nonstring__ to bits/utmp.h, but it did not update
the parallel bits/utmpx.h header. In struct utmp, the nonstring
attribute for ut_id was missing.
C2X (current version in git, postdating the most recent public draft
available as a PDF on the WG14 website) adds the interfaces from TS
18661-4, other than the reduction functions, as unconditionally
required and visible in <math.h> for hosted implementations; the
__STDC_WANT_IEC_60559_FUNCS_EXT__ macro is not included in C2X at all
(as the reduction functions aren't included at all, expected to end up
in a version of the TS updated to be relative to C2X).
This patch updates the glibc headers accordingly, following the same
pattern used for 18661-1 functions. As the only 18661-4 functions
currently supported are the exp10 functions that have been in glibc
for a very long time, this means that in fact __GLIBC_USE
(IEC_60559_FUNCS_EXT) ends up being used only to determine the
definition of __GLIBC_USE_IEC_60559_FUNCS_EXT_C2X, not yet in any
headers other than bits/libc-header-start.h.
(I hope to add the other 18661-4 functions to glibc at some point; the
main complication is the current lack of MPFR support for many of
these functions.)
Tested for x86_64.
* bits/libc-header-start.h (__GLIBC_USE_IEC_60559_FUNCS_EXT):
Update comment.
(__GLIBC_USE_IEC_60559_FUNCS_EXT_C2X): New macro.
* bits/math-finite.h [__GLIBC_USE (IEC_60559_FUNCS_EXT)]: Change
to [__GLIBC_USE (IEC_60559_FUNCS_EXT_C2X)].
* math/bits/mathcalls.h [__GLIBC_USE (IEC_60559_FUNCS_EXT)]:
Likewise.
The tgkill function is sometimes used in crash handlers.
<bits/signal_ext.h> follows the same approach as <bits/unistd_ext.h>
(which was added for the gettid system call wrapper).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
The stub implementations are turned into compat symbols.
Linux actually has two reserved system call numbers (for getpmsg
and putpmsg), but these system calls have never been implemented,
and there are no plans to implement them, so this patch replaces
the wrappers with the generic stubs.
According to <https://bugzilla.redhat.com/show_bug.cgi?id=436349>,
the presence of the XSI STREAMS declarations is a minor portability
hazard because they are not actually implemented.
This commit does not change the TIRPC support code in
sunrpc/rpc_svcout.c. It uses additional XTI functionality and
therefore never worked with glibc.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
sysdeps/ia64/fpu/bits/math-finite.h exists and will be installed on
ia64, but during the build, the default math/bits/math-finite.h file
is used, which is wrong.
Fixes commit 0ac5ae2335 ("Optimize
libm").
No functional change; the previous path worked as well, but it
re-added the obsolete sysdeps/generic/bits directory, which was
removed (for the first time) in commit
c72565e5f1.
Fixes commit e47d82c99a ("Provide
<bits/unistd_ext.h> as a sysdeps header exclusively").
glibc support for 64-bit time_t on 32-bit architectures
will involve:
- Using 64-bit times inside glibc, with conversions
to and from 32-bit times taking place as necessary
for interfaces using such times.
- Adding 64-bit-time support in the glibc public API.
This support should be dynamic, i.e. glibc should
provide both 32-bit and 64-bit implementations and
let user code choose at compile time whether to use
the 32-bit or 64-bit interfaces.
This requires a glibc-internal name for a type for times
that are always 64-bit.
Based on __TIMESIZE, a new macro is defined, __TIME64_T_TYPE,
which is always the right __*_T_TYPE to hold a 64-bit-time.
__TIME64_T_TYPE equals __TIME_T_TYPE if __TIMESIZE equals 64
and equals __SQUAD_T_TYPE otherwise.
__time64_t can then replace uses of internal_time_t.
This patch was tested by running 'make check' on branch
master then applying this patch and its predecessor and
running 'make check' again, and checking that both 'make
check' yield identical results. This was done on
x86_64-linux-gnu and i686-linux-gnu.
* bits/time64.h: New file.
* include/time.h: Replace internal_time_t with __time64_t.
* posix/bits/types (__time64_t): Add.
* stdlib/Makefile: Add bits/time64.h to includes.
* time/tzfile.c: Replace internal_time_t with __time64_t.
To determine whether the default time_t interfaces are 32-bit
and so need conversions, or are 64-bit and so are compatible
with the internal 64-bit type without conversions, a macro
giving the size of the default time_t is also required.
This macro is called __TIMESIZE.
This macro can then be used instead of __WORDSIZE in msq-pad.h
and shm-pad.h files, which in turn allows removing their x86
variants, and in sem-pad.h files but keeping the x86 variant.
This patch was tested by running 'make check' on branch master
then applying this patch and running 'make check' again, and
checking that both 'make check' yield identical results.
This was done on x86_64-linux-gnu and i686-linux-gnu.
* bits/timesize.h: New file.
* stdlib/Makefile (headers): Add bits/timesize.h.
* sysdeps/unix/sysv/linux/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME): Use __TIMESIZE instead of __WORDSIZE.
* sysdeps/unix/sysv/linux/bits/sem-pad.h
(__SEM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/bits/shm-pad.h
(__SHM_PAD_AFTER_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/hppa/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/mips/bits/msq-pad.h
(__MSQ_PAD_AFTER_TIME, __MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/powerpc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME, __SHM_PAD_BETWEEN_TIME_AND_SEGSZ): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/msq-pad.h
(__MSQ_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/sem-pad.h
(__SEM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/sparc/bits/shm-pad.h
(__SHM_PAD_BEFORE_TIME): Likewise.
* sysdeps/unix/sysv/linux/x86/bits/msq-pad.h: Delete file.
* sysdeps/unix/sysv/linux/x86/bits/shm-pad.h: Likewise.
* sysdeps/unix/sysv/linux/x86/bits/timesize.h: New file.
Add <bits/indirect-return.h> and include it in <ucontext.h>.
__INDIRECT_RETURN defined in <bits/indirect-return.h> indicates if
swapcontext requires special compiler treatment. The default
__INDIRECT_RETURN is empty.
On x86, when shadow stack is enabled, __INDIRECT_RETURN is defined
with indirect_return attribute, which has been added to GCC 9, to
indicate that swapcontext returns via indirect branch. Otherwise
__INDIRECT_RETURN is defined with returns_twice attribute.
When shadow stack is enabled, remove always_inline attribute from
prepare_test_buffer in string/tst-xbzero-opt.c to avoid:
tst-xbzero-opt.c: In function ‘prepare_test_buffer’:
tst-xbzero-opt.c:105:1: error: function ‘prepare_test_buffer’ can never be inlined because it uses setjmp
prepare_test_buffer (unsigned char *buf)
when indirect_return attribute isn't available.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
* bits/indirect-return.h: New file.
* misc/sys/cdefs.h (__glibc_has_attribute): New.
* sysdeps/x86/bits/indirect-return.h: Likewise.
* stdlib/Makefile (headers): Add bits/indirect-return.h.
* stdlib/ucontext.h: Include <bits/indirect-return.h>.
(swapcontext): Add __INDIRECT_RETURN.
* string/tst-xbzero-opt.c (ALWAYS_INLINE): New.
(prepare_test_buffer): Use it.
When compiling C++ code with -mabi=ieeelongdouble, KCtype is
unavailable and the long double type should be used instead.
This is also providing macro __HAVE_FLOAT128_UNLIKE_LDBL in order to
identify the kind of long double type is being used in the current
compilation unit.
Notice that bits/floatn.h cannot benefit from the new macro due to order
of header inclusion.
* bits/floatn-common.h: Define __HAVE_FLOAT128_UNLIKE_LDBL.
* math/math.h: Restrict the prototype definition for the functions
issignaling(_Float128) and iszero(_Float128); and template
__iseqsig_type<_Float128>, from __HAVE_DISTINCT_FLOAT128 to
__HAVE_FLOAT128_UNLIKE_LDBL.
* sysdeps/powerpc/bits/floatn.h [__HAVE_FLOAT128
&& (!__GNUC_PREREQ (7, 0) || defined __cplusplus)
&& __LDBL_MANT_DIG__ == 113]: Use long double suffix for
__f128() constants; define the type _Float128 as long double;
and reuse long double in __CFLOAT128.
Signed-off-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
As for sysctl, ustat has been deprecated in favor of {f}statfs. Also
some newer ports which uses generic interface builds a stub version that
returns ENOSYS.
This patch deprecates ustat interface by removing ustat.h related headers,
adding a compatibility symbol, and avoiding new ports to build and provide
the symbol.
Checked on x86_64-linux-gnu and i686-linux-gnu. Also checked with a
check-abi on all affected ABIs.
* NEWS: Add ustat.h deprecation entry.
* bits/ustat.h: Remove file.
* misc/sys/ustat.h: Likewise.
* misc/ustat.h: Likewise.
* sysdeps/unix/sysv/linux/generic/ustat.c: Likewise.
* misc/Makefile (headers): Remove ustat.h and sys/ustat.h.
* misc/ustat.c (__ustat): Rename to __old_ustat and export only in
compatibility mode.
* sysdeps/unix/sysv/linux/ustat.c (__ustat): Likewise.
* sysdeps/unix/sysv/linux/mips/ustat.c: Define DEV_TO_KDEV and use
generic Linux implementation.
* bits/sched.h: Include <bits/types/struct_sched_param.h> and move struct
sched_param definition to it.
* sysdeps/unix/sysv/linux/bits/sched.h: Likewise.
* bits/types/struct_sched_param.h: New file.
* sysdeps/htl/bits/types/struct___pthread_attr.h: Include
<bits/types/struct_sched_param.h> instead of <sched.h>.
* posix/Makefile (headers): Add bits/types/struct_sched_param.h.
* bits/in.h [!__USE_MISC]: Do not define struct ip_opts.
* conform/data/netinet/in.h-data: Allow sin_ and sin6_ prefix.
* sysdeps/gnu/bits/msq.h (struct msqid_ds): Use __wait_queue struct
instead of wait_queue.
* sysdeps/gnu/bits/shm.h (struct shmid_ds): Use __vm_area_struct
instead of vm_area_struct.
This patch defines _DIRENT_MATCHES_DIRENT64 to either 0 or 1 and adjust its
usage from checking its definition to its value.
Checked on a build for major Linux abis.
* bits/dirent.h (__INO_T_MATCHES_INO64_T): Define regardless whether
__INO_T_MATCHES_INO64_T is defined.
* sysdeps/unix/sysv/linux/bits/dirent.h: Likewise.
* dirent/alphasort.c: Check _DIRENT_MATCHES_DIRENT64 value instead
of definition.
* dirent/alphasort64.c: Likewise.
* dirent/scandir.c: Likewise.
* dirent/scandir64-tail.c: Likewise.
* dirent/scandir64.c: Likewise.
* dirent/scandirat.c: Likewise.
* dirent/scandirat64.c: Likewise.
* dirent/versionsort.c: Likewise.
* dirent/versionsort64.c: Likewise.
* include/dirent.h: Likewise.
so interfaces needing it can get it.
* stdlib/errno.h (error_t): Move definition to...
* bits/types/error_t.h: ... new header.
* stdlib/Makefile (headers): Add bits/types/error_t.h.
* sysdeps/mach/hurd/bits/errno.h (error_t): Move definition to...
* sysdeps/mach/hurd/bits/types/error_t.h: ... new header.
* sysdeps/mach/hurd/errnos.awk (error_t): Likewise.
* hurd/hurd.h: Include <bits/types/error_t.h>
* hurd/hurd/fd.h: Include <bits/types/error_t.h>
* hurd/hurd/id.h: Include <errno.h> and <bits/types/error_t.h>
* hurd/hurd/lookup.h: Include <errno.h> and <bits/types/error_t.h>
* hurd/hurd/resource.h: Include <bits/types/error_t.h>
* hurd/hurd/signal.h: Include <bits/types/error_t.h>
* hurd/hurd/sigpreempt.h: Include <bits/types/error_t.h>
Nearly everything in _G_config.h is either junk or more appropriately
defined elsewhere:
* _G_fpos_t, _G_fpos64_t, and _G_BUFSIZ are already completely unused.
* All remaining uses of _G_va_list have been changed to __gnuc_va_list.
* The definition of _G_HAVE_ST_BLKSIZE/_IO_HAVE_ST_BLKSIZE has
been inlined into its sole use.
* The complete definition of _G_iconv_t has been moved to libio.h and
renamed _IO_iconv_t (all actual users used that name).
* _G_IO_IO_FILE_VERSION is vestigial; some code cares whether
_IO_stdin_used exists, but nothing looks at its value. I've
preserved the value as a hardwired constant in csu/init.c.
This means csu/init.c no longer needs to include anything.
* Many of the headers included by _G_config.h were already being
included directly by either either libio.h or stdio.h; the
remaining ones were moved to libio.h.
* _G_HAVE_MREMAP is still relevant, because mremap genuinely is a
Linux extension; it's not in POSIX and as far as I can tell it's
not available on the Hurd either. I also preserved _G_HAVE_MMAP,
since it's conceivable someone would want to port glibc to a
MMU-less, mmap-less environment in the future. Both are now always
defined to 1/0 as is the current convention, instead of the older
1/undef convention. These are the only symbols still defined in
_G_config.h.
* The actual inclusion of _G_config.h moves from libio.h to libioP.h,
as this is where a potential override of _G_HAVE_MMAP happens.
* The #ifdef logic in libioP.h controlling _IO_JUMPS_OFFSET has been
simplified.
After this patch, the only surviving _G_ symbols are the struct tag
names _G_fpos_t and _G_fpos64_t, which are preserved for the sake of
C++ mangled names in applications, and _G_HAVE_MMAP and _G_HAVE_MREMAP,
which do not seem worth renaming.
Installed stripped libraries are unchanged by this patch.
* bits/_G_config.h: Move back to sysdeps/generic/_G_config.h.
Delete all contents except for definitions of _G_HAVE_MMAP and
_G_HAVE_MREMAP. Add commentary explaining those two symbols.
* sysdeps/unix/sysv/linux/bits/_G_config.h: Move back to
sysdeps/unix/sysv/linux/_G_config.h. Make same content
change as above.
* libio/libio.h: Don't include bits/_G_config.h here.
Include stddef.h with __need_wchar_t defined. Include
bits/types/__mbstate_t.h, bits/types/wint_t.h, and gconv.h.
Define _IO_iconv_t here, directly.
Don't define _IO_HAVE_ST_BLKSIZE.
* libio/libioP.h: Include _G_config.h here. Move include of
shlib-compat.h up with rest of includes. Simplify conditionals
controlling definition of _IO_JUMPS_OFFSET.
* csu/init.c: Remove always-true #if around entire file.
Don't include stdio.h. Set _IO_stdin_used to hardwired
constant 0x20001, and update commentary.
* include/stdio.h, sysdeps/ieee754/ldbl-opt/nldbl-compat.h:
Replace all uses of _G_va_list with __gnuc_va_list.
* libio/filedoalloc.c: Use #if defined _STATBUF_ST_BLKSIZE
instead of #if _IO_HAVE_ST_BLKSIZE.
* libio/fileops.c: Test _G_HAVE_MREMAP with #if, not #ifdef.
* libio/iofdopen.c, libio/iofopen.c: Test _G_HAVE_MMAP with #if,
not #ifdef.
We shipped 2.27 with libio.h and _G_config.h still installed but
issuing warnings when used. Let's stop installing them early in 2.28
so that we have plenty of time to think of another plan if there are
problems.
The public stdio.h had a genuine dependency on libio.h for the
complete definitions of FILE and cookie_io_functions_t, and a genuine
dependency on _G_config.h for the complete definitions of fpos_t and
fpos64_t; these are moved to single-type headers.
bits/types/struct_FILE.h also provides a handful of accessor and
bitflags macros so that code is not duplicated between bits/stdio.h
and libio.h. All the other _IO_ and _G_ names used by the public
stdio.h can be replaced with either public names or __-names.
In order to minimize the risk of breaking our own compatibility code,
bits/types/struct_FILE.h preserves the _IO_USE_OLD_IO_FILE mechanism
exactly as it was in libio.h, but you have to define _LIBC to use it,
or it'll error out. Similarly, _IO_lock_t_defined is preserved
exactly, but will error out if used without defining _LIBC.
Internally, include/stdio.h continues to include libio.h, and libio.h
scrupulously provides every _IO_* and _G_* name that it always did,
perhaps now defined in terms of the public names. This is how this
patch avoids touching dozens of files throughout glibc and becoming
entangled with the _IO_MTSAFE_IO mess. The remaining patches in this
series eliminate most of the _G_ names.
Tested on x86_64-linux; in addition to the test suite, I installed the
library in a sysroot and verified that a simple program that uses
stdio.h could be compiled against the installed library, and I also
verified that installed stripped libraries are unchanged.
* libio/bits/types/__fpos_t.h, libio/bits/types/__fpos64_t.h:
New single-type headers split from _G_config.h.
* libio/bits/types/cookie_io_functions_t.h
* libio/bits/types/struct_FILE.h
New single-type headers split from libio.h.
* libio/Makefile: Install the above new headers. Don't install
libio.h, _G_config.h, bits/libio.h, bits/_G_config.h, or
bits/libio-ldbl.h.
* libio/_G_config.h, libio/libio.h: Delete file.
* libio/bits/libio.h: Remove improper-inclusion guard.
Include stdio.h and don't repeat anything that it does.
Define _IO_fpos_t as __fpos_t, _IO_fpos64_t as __fpos64_t,
_IO_BUFSIZ as BUFSIZ, _IO_va_list as __gnuc_va_list,
__io_read_fn as cookie_read_function_t,
__io_write_fn as cookie_write_function_t,
__io_seek_fn as cookie_seek_function_t,
__io_close_fn as cookie_close_function_t,
and _IO_cookie_io_functions_t as cookie_io_functions_t.
Define _STDIO_USES_IOSTREAM, __HAVE_COLUMN, and _IO_file_flags
here, in the "compatibility defines" section. Remove an #if 0
block. Use the "body" macros from bits/types/struct_FILE.h to
define _IO_getc_unlocked, _IO_putc_unlocked, _IO_feof_unlocked,
and _IO_ferror_unlocked.
Move prototypes of __uflow and __overflow...
* libio/stdio.h: ...here. Don't include bits/libio.h.
Don't define _STDIO_USES_IOSTREAM. Get __gnuc_va_list
directly from stdarg.h. Include bits/types/__fpos_t.h,
bits/types/__fpos64_t.h, bits/types/struct_FILE.h,
and, when __USE_GNU, bits/types/cookie_io_functions_t.h.
Use __gnuc_va_list, not _G_va_list; __fpos_t, not _G_fpos_t;
__fpos64_t, not _G_fpos64_t; FILE, not struct _IO_FILE;
cookie_io_functions_t, not _IO_cookie_io_functions_t;
__ssize_t, not _IO_ssize_t. Unconditionally define
BUFSIZ as 8192 and EOF as (-1).
* libio/bits/stdio.h: Add multiple-include guard. Use the "body"
macros from bits/types/struct_FILE.h instead of _IO_* macros
from libio.h; use __gnuc_va_list instead of va_list and __ssize_t
instead of _IO_ssize_t.
* libio/bits/stdio2.h: Similarly.
* libio/iolibio.h: Add multiple-include guard.
Include bits/libio.h after stdio.h.
* libio/libioP.h: Add multiple-include guard.
Include stdio.h and bits/libio.h before iolibio.h.
* include/bits/types/__fpos_t.h, include/bits/types/__fpos64_t.h
* include/bits/types/cookie_io_functions_t.h
* include/bits/types/struct_FILE.h: New wrappers.
* bits/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h:
Get definitions of _G_fpos_t and _G_fpos64_t from
bits/types/__fpos_t.h and bits/types/__fpos64_t.h
respectively. Remove improper-inclusion guards.
* conform/data/stdio.h-data: Update expectations of va_list.
* scripts/check-installed-headers.sh: Remove special case for
libio.h and _G_config.h.
We have a general principle of preferring optimizations for library
facilities to use compiler built-in functions rather than being
located in library headers, where the compiler can reasonably optimize
code without needing to know glibc implementation details.
This patch applies this principle to bits/byteswap.h, eliminating all
the architecture-specific variants and bits/byteswap-16.h. The
__bswap_16, __bswap_32 and __bswap_64 interfaces all become inline
functions, never macros, using the GCC built-in functions where
available and otherwise a single architecture-independent definition
using shifts and masking (which compilers may well be able to detect
and optimize; GCC has detection of various byte-swapping idioms).
The __bswap_constant_32 macro needs to stay around because of uses in
static initializers within glibc and its tests, and so for consistency
all __bswap_constant_* are kept rather than just being inlined into
the old-GCC-or-non-GCC parts of the __bswap_* inline function
definitions.
Various open bugs are addressed by this cleanup, with caveats about
exactly what is covered by those bugs and when the bugs applied at
all.
Bug 14508 reports -Wformat warnings building glibc because __bswap_*
sometimes returned the wrong types. Obviously we already don't have
such warnings any more or the build would be failing, given -Werror,
and I suspect that bug was originally for wrong types for x86_64, as
fixed by commit d394eb742a (glibc 2.17).
The only case I saw removed by this patch where the types would still
have been wrong was the non-__GNUC__ case of __bswap_64 in the s390
header (using unsigned long long int, but uint64_t would be unsigned
long int for 64-bit). In any case, the single header consistently
uses __uintN_t types after this patch, thereby eliminating all such
bugs. The existing string/test-endian-types.c test already suffices
to verify that the types are correct with the compiler used to build
glibc and its tests.
Bug 15512 reports an error from __bswap_constant_16 with -Werror
-Wsign-conversion. I am unable to reproduce this with any GCC version
supporting -Wsign-conversion - all seem to be able to avoid warning
for ((x) >> 8) & 0xffu, where x is uint16_t, which while it formally
does involve an implicit conversion from int to unsigned int, is also
a case where it should be easy for the compiler to see that the value
converted is never negative. But in this patch __bswap_constant_16 is
changed to use signed 0xff so that no such implicit conversion occurs
at all, and a test with -Werror -Wsign-conversion is added.
Bug 17082 objects to the use of ({}) statement expressions in these
macros preventing use at file scope (in C, that's in sizeof etc.; in
C++, more generally in static initializers). The particular case of
these interfaces is fixed by this patch as it changes them to inline
functions, eliminating all uses of ({}) in bits/byteswap.h, and a
corresponding testcase is added. The bug tries to raise a more
general policy question about use of ({}) in macros in installed
headers, referring to "many other libc functions" (unspecified which
functions are being considered).
Since such policy questions belong on libc-alpha, and since there
*are* macros in installed headers which can't really avoid using ({})
(where they are type-generic, so can't use an inline function, but
need a temporary variable, and a few where the interface involves
returning memory from alloca so can't use an inline function either),
I propose to consider that bug fixed with this change. That is
without prejudice to any other new bugs anyone wishes to file *for
precisely defined sets of macros* requesting moving away from ({})
*where it is clearly possible for those interfaces*. Where ({}) can
be avoided, typically by use of an inline function, I think that's a
good idea - that inline functions are typically to be preferred to
({}) for header interfaces where such optimizations are useful but the
interface is suited to being defined using an inline function.
Bug 20530 requests use of __builtin_bswap16 when available (GCC 4.8
and later), which this patch implements.
Tested for x86_64, and with build-many-glibcs.py. Also did an x86_64
test with the __GNUC_PREREQ conditionals changed to "#if 0" to verify
the old-GCC/non-GCC case in the headers. (There are already existing
tests for correctness of results of these interfaces.)
[BZ #14508]
[BZ #15512]
[BZ #17082]
[BZ #20530]
* bits/byteswap.h: Update file comment. Do not include
<bits/byteswap-16.h>.
(__bswap_constant_16): Cast result to __uint16_t. Use signed 0xff
constant.
(__bswap_16): Define as inline function.
(__bswap_constant_32): Reformat definition.
(__bswap_32): Always define as inline function, not macro, using
__uint32_t. Use __builtin_bswap32 if [__GNUC_PREREQ (4, 3)],
otherwise __bswap_constant_32.
(__bswap_constant_64): Reformat definition. Do not use
__extension__ here.
(__bswap_64): Always define as inline function, not macro. Use
__extension__ on function definition. Use __builtin_bswap64 if
[__GNUC_PREREQ (4, 3)], otherwise __bswap_constant_64.
* string/test-endian-file-scope.c: New file.
* string/test-endian-sign-conversion.c: Likewise.
* string/Makefile (headers): Remove bits/byteswap-16.h.
(tests): Add test-endian-file-scope and
test-endian-sign-conversion.
(CFLAGS-test-endian-sign-conversion.c): New variable.
* bits/byteswap-16.h: Remove file.
* sysdeps/ia64/bits/byteswap-16.h: Likewise.
* sysdeps/ia64/bits/byteswap.h: Likewise.
* sysdeps/m68k/bits/byteswap.h: Likewise.
* sysdeps/s390/bits/byteswap-16.h: Likewise.
* sysdeps/s390/bits/byteswap.h: Likewise.
* sysdeps/tile/bits/byteswap.h: Likewise.
* sysdeps/x86/bits/byteswap-16.h: Likewise.
* sysdeps/x86/bits/byteswap.h: Likewise.
