C23 adds a header <stdbit.h> with various functions and type-generic
macros for bit-manipulation of unsigned integers (plus macro defines
related to endianness). Implement this header for glibc.
The functions have both inline definitions in the header (referenced
by macros defined in the header) and copies with external linkage in
the library (which are implemented in terms of those macros to avoid
duplication). They are documented in the glibc manual. Tests, as
well as verifying results for various inputs (of both the macros and
the out-of-line functions), verify the types of those results (which
showed up a bug in an earlier version with the type-generic macro
stdc_has_single_bit wrongly returning a promoted type), that the
macros can be used at top level in a source file (so don't use ({})),
that they evaluate their arguments exactly once, and that the macros
for the type-specific functions have the expected implicit conversions
to the relevant argument type.
Jakub previously referred to -Wconversion warnings in type-generic
macros, so I've included a test with -Wconversion (but the only
warnings I saw and fixed from that test were actually in inline
functions in the <stdbit.h> header - not anything coming from use of
the type-generic macros themselves).
This implementation of the type-generic macros does not handle
unsigned __int128, or unsigned _BitInt types with a width other than
that of a standard integer type (and C23 doesn't require the header to
handle such types either). Support for those types, using the new
type-generic built-in functions Jakub's added for GCC 14, can
reasonably be added in a followup (along of course with associated
tests).
This implementation doesn't do anything special to handle C++, or have
any tests of functionality in C++ beyond the existing tests that all
headers can be compiled in C++ code; it's not clear exactly what form
this header should take in C++, but probably not one using macros.
DIS ballot comment AT-107 asks for the word "count" to be added to the
names of the stdc_leading_zeros, stdc_leading_ones,
stdc_trailing_zeros and stdc_trailing_ones functions and macros. I
don't think it's likely to be accepted (accepting any technical
comments would mean having an FDIS ballot), but if it is accepted at
the WG14 meeting (22-26 January in Strasbourg, starting with DIS
ballot comment handling) then there would still be time to update
glibc for the renaming before the 2.39 release.
The new functions and header are placed in the stdlib/ directory in
glibc, rather than creating a new toplevel stdbit/ or putting them in
string/ alongside ffs.
Tested for x86_64 and x86.
C2x adds binary integer constants starting with 0b or 0B, and supports
those constants in strtol-family functions when the base passed is 0
or 2. Implement that strtol support for glibc.
As discussed at
<https://sourceware.org/pipermail/libc-alpha/2020-December/120414.html>,
this is incompatible with previous C standard versions, in that such
an input string starting with 0b or 0B was previously required to be
parsed as 0 (with the rest of the string unprocessed). Thus, as
proposed there, this patch adds 20 new __isoc23_* functions with
appropriate header redirection support. This patch does *not* do
anything about scanf %i (which will need 12 new functions per long
double variant, so 12, 24 or 36 depending on the glibc configuration),
instead leaving that for a future patch. The function names would
remain as __isoc23_* even if C2x ends up published in 2024 rather than
2023.
Making this change leads to the question of what should happen to
internal uses of these functions in glibc and its tests. The header
redirection (which applies for _GNU_SOURCE or any other feature test
macros enabling C2x features) has the effect of redirecting internal
uses but without those uses then ending up at a hidden alias (see the
comment in include/stdio.h about interaction with libc_hidden_proto).
It seems desirable for the default for internal uses to be the same
versions used by normal code using _GNU_SOURCE, so rather than doing
anything to disable that redirection, similar macro definitions to
those in include/stdio.h are added to the include/ headers for the new
functions.
Given that the default for uses in glibc is for the redirections to
apply, the next question is whether the C2x semantics are correct for
all those uses. Uses with the base fixed to 10, 16 or any other value
other than 0 or 2 can be ignored. I think this leaves the following
internal uses to consider (an important consideration for review of
this patch will be both whether this list is complete and whether my
conclusions on all entries in it are correct):
benchtests/bench-malloc-simple.c
benchtests/bench-string.h
elf/sotruss-lib.c
math/libm-test-support.c
nptl/perf.c
nscd/nscd_conf.c
nss/nss_files/files-parse.c
posix/tst-fnmatch.c
posix/wordexp.c
resolv/inet_addr.c
rt/tst-mqueue7.c
soft-fp/testit.c
stdlib/fmtmsg.c
support/support_test_main.c
support/test-container.c
sysdeps/pthread/tst-mutex10.c
I think all of these places are OK with the new semantics, except for
resolv/inet_addr.c, where the POSIX semantics of inet_addr do not
allow for binary constants; thus, I changed that file (to use
__strtoul_internal, whose semantics are unchanged) and added a test
for this case. In the case of posix/wordexp.c I think accepting
binary constants is OK since POSIX explicitly allows additional forms
of shell arithmetic expressions, and in stdlib/fmtmsg.c SEV_LEVEL is
not in POSIX so again I think accepting binary constants is OK.
Functions such as __strtol_internal, which are only exported for
compatibility with old binaries from when those were used in inline
functions in headers, have unchanged semantics; the __*_l_internal
versions (purely internal to libc and not exported) have a new
argument to specify whether to accept binary constants.
As well as for the standard functions, the header redirection also
applies to the *_l versions (GNU extensions), and to legacy functions
such as strtoq, to avoid confusing inconsistency (the *q functions
redirect to __isoc23_*ll rather than needing their own __isoc23_*
entry points). For the functions that are only declared with
_GNU_SOURCE, this means the old versions are no longer available for
normal user programs at all. An internal __GLIBC_USE_C2X_STRTOL macro
is used to control the redirections in the headers, and cases in glibc
that wish to avoid the redirections - the function implementations
themselves and the tests of the old versions of the GNU functions -
then undefine and redefine that macro to allow the old versions to be
accessed. (There would of course be greater complexity should we wish
to make any of the old versions into compat symbols / avoid them being
defined at all for new glibc ABIs.)
strtol_l.c has some similarity to strtol.c in gnulib, but has already
diverged some way (and isn't listed at all at
https://sourceware.org/glibc/wiki/SharedSourceFiles unlike strtoll.c
and strtoul.c); I haven't made any attempts at gnulib compatibility in
the changes to that file.
I note incidentally that inttypes.h and wchar.h are missing the
__nonnull present on declarations of this family of functions in
stdlib.h; I didn't make any changes in that regard for the new
declarations added.
The implementation is based on scalar Chacha20 with per-thread cache.
It uses getrandom or /dev/urandom as fallback to get the initial entropy,
and reseeds the internal state on every 16MB of consumed buffer.
To improve performance and lower memory consumption the per-thread cache
is allocated lazily on first arc4random functions call, and if the
memory allocation fails getentropy or /dev/urandom is used as fallback.
The cache is also cleared on thread exit iff it was initialized (so if
arc4random is not called it is not touched).
Although it is lock-free, arc4random is still not async-signal-safe
(the per thread state is not updated atomically).
The ChaCha20 implementation is based on RFC8439 [1], omitting the final
XOR of the keystream with the plaintext because the plaintext is a
stream of zeros. This strategy is similar to what OpenBSD arc4random
does.
The arc4random_uniform is based on previous work by Florian Weimer,
where the algorithm is based on Jérémie Lumbroso paper Optimal Discrete
Uniform Generation from Coin Flips, and Applications (2013) [2], who
credits Donald E. Knuth and Andrew C. Yao, The complexity of nonuniform
random number generation (1976), for solving the general case.
The main advantage of this method is the that the unit of randomness is not
the uniform random variable (uint32_t), but a random bit. It optimizes the
internal buffer sampling by initially consuming a 32-bit random variable
and then sampling byte per byte. Depending of the upper bound requested,
it might lead to better CPU utilization.
Checked on x86_64-linux-gnu, aarch64-linux, and powerpc64le-linux-gnu.
Co-authored-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Yann Droneaud <ydroneaud@opteya.com>
[1] https://datatracker.ietf.org/doc/html/rfc8439
[2] https://arxiv.org/pdf/1304.1916.pdf
__fentry__ symbol is currently not defined for other architectures.
Attempts to introduce it cause abicheck to fail, because it will be
available since 2.29 earliest, and not 2.13, which is the case for
Intel. With the new code, abicheck passes for i686-linux-gnu,
x86_64-linux-gnu and x86_64-linux-gnu32 triples.
ChangeLog:
* stdlib/Versions: Remove __fentry__.
* sysdeps/i386/Versions: Add __fentry__.
* sysdeps/x86_64/Versions: Add __fentry__.
This patch continues filling out TS 18661-3 support by adding *f64 and
*f32x function aliases, supporting _Float64 and _Float32x, as aliases
for double functions. These types are supported for all glibc
configurations. The API corresponds exactly to that for _Float128 and
_Float64x. _Float32 aliases to float functions remain to be added in
subsequent patches to complete this process (then there are a few
miscellaneous functions in TS 18661-3 to implement that aren't simply
versions of existing functions for new types).
The patch enables the feature in bits/floatn-common.h, adds symbol
versions and documentation with updates to ABI baselines, and arranges
for the libm functions for the new types to be tested. As with the
_Float64x changes there are some x86 ulps updates because of header
inlines not used for the new types (and one other change to the
non-multiarch libm-test-ulps, which I suppose comes from using a
different compiler version / configuration from when it was last
regenerated).
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* bits/floatn-common.h (__HAVE_FLOAT64): Define to 1.
(__HAVE_FLOAT32X): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64
and _Float32x.
* math/Makefile (test-types): Add float64 and float32x.
* math/Versions (GLIBC_2.27): Add _Float64 and _Float32x
functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/arm/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/hppa/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/coldfire/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/m68k/m680x0/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/microblaze/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/fpu/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/nios2/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/fpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sh/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx32/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libc.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilegx/tilegx64/libm.abilist:
Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/tile/tilepro/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
This patch continues filling out TS 18661-3 support by adding *f64x
function aliases on platforms with _Float64x support. (It so happens
the set of such platforms is exactly the same as the set of platforms
with _Float128 support, although on x86_64, x86 and ia32 the _Float64x
format is Intel extended rather than binary128.) The API provided
corresponds exactly to that provided for _Float128, mostly coming from
TS 18661-3. As these functions always alias those for another type
(long double, _Float128 or both), __* function names are not provided,
as in other cases of alias types.
Given the preparation done in previous patches, this one just enables
the feature via Makeconfig and bits/floatn.h, adds symbol versions,
and updates documentation and ABI baselines. The symbol versions are
present unconditionally as GLIBC_2.27 in the relevant Versions files,
as it's OK for those to specify versions for functions that may not be
present in some configurations; no additional complexity is needed
unless in future some configuration gains support for this type that
didn't have such support in 2.27. The Makeconfig additions for ia64
and x86 aren't strictly needed, as those configurations also get
float64x-alias-fcts definitions from
sysdeps/ieee754/float128/Makeconfig, but still seem appropriate given
that _Float64x is not _Float128 for those configurations.
A libm-test-ulps update for x86 is included. This is because
bits/mathinline.h does not have _Float64x support added and for two
functions the use of out-of-line functions results in increased ulps
(ifloat64x shares ulps with ildouble / ifloat128 as appropriate).
Given that we'd like generally to eliminate bits/mathinline.h
optimizations, preferring to have such optimizations in GCC instead,
it seems reasonable not to add such support there for new types. GCC
support for _FloatN / _FloatNx built-in functions is limited, but has
been improved in GCC 8, and at some point I hope the full set of libm
built-in functions in GCC, and other optimizations with
per-floating-type aspects, will be enabled for all _FloatN / _FloatNx
types.
Tested for x86_64 and x86, and with build-many-glibcs.py, with both
GCC 6 and GCC 7.
* sysdeps/ia64/Makeconfig (float64x-alias-fcts): New variable.
* sysdeps/ieee754/float128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/ieee754/ldbl-128/Makeconfig (float64x-alias-fcts):
Likewise.
* sysdeps/x86/Makeconfig: New file.
* bits/floatn-common.h (__HAVE_FLOAT64X): Remove macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* bits/floatn.h (__HAVE_FLOAT64X): New macro.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ia64/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/ieee754/ldbl-128/bits/floatn.h (__HAVE_FLOAT64X):
Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/mips/ieee754/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/powerpc/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* sysdeps/x86/bits/floatn.h (__HAVE_FLOAT64X): Likewise.
(__HAVE_FLOAT64X_LONG_DOUBLE): Likewise.
* manual/math.texi (Mathematics): Document support for _Float64x.
* math/Versions (GLIBC_2.27): Add _Float64x functions.
* stdlib/Versions (GLIBC_2.27): Likewise.
* wcsmbs/Versions (GLIBC_2.27): Likewise.
* sysdeps/unix/sysv/linux/aarch64/libc.abilist: Update.
* sysdeps/unix/sysv/linux/aarch64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/alpha/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/i386/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/ia64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/mips/mips64/n64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libc-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/powerpc/powerpc64/libm-le.abilist:
Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/s390/s390-64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc32/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/sparc/sparc64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/64/libm.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libc.abilist: Likewise.
* sysdeps/unix/sysv/linux/x86_64/x32/libm.abilist: Likewise.
* sysdeps/i386/fpu/libm-test-ulps: Likewise.
* sysdeps/i386/i686/fpu/multiarch/libm-test-ulps: Likewise.
This patch moves wcstof128 and wcstof128_l Versions file entries from
stdlib/Versions to wcsmbs/Versions, which is a more appropriate place
for them.
Tested for x86_64, and with build-many-glibcs.py that installed
stripped shared libraries are unchanged by the patch.
* stdlib/Versions (libc): Move entries for wcstof128 and
wcstof128_l to ....
* wcsmbs/Versions (libc): ... here.
Include <float128-abi.h>.
With support for _Float128 functions on platforms where that type has
the same ABI as long double, as well as on platforms where it is
ABI-distinct, those functions will need to be exported from glibc's
shared libraries at appropriate symbol versions in each case.
This patch avoids duplication of lists of symbols to export by moving
the symbols other than __* to math/Versions and stdlib/Versions.
There, they are conditional on <float128-abi.h> defining
FLOAT128_VERSION and a default version of that header is added that
does not define that macro. Enabling the float128 function aliases
will then include adding a sysdeps/ieee754/ldbl-128/float128-abi.h
that defines FLOAT128_VERSION to GLIBC_2.27. Symbols __* remain in
sysdeps/ieee754/float128/Versions; those symbols should be present
only once per floating-point format, not once per type.
Note that if any platforms currently lacking support for a type with
binary128 format get glibc support for such a type in future (whether
only as _Float128, or also as a new long double format), and new libm
functions (present for all types) have been added by then, additional
macros will be needed to allow such functions to get a version of the
form "GLIBC_2.28 if the platform had _Float128 support by then, or the
later version at which that platform had _Float128 support added".
This is not however a preexisting condition, but would have applied
equally to the existing support for _Float128 as an ABI-distinct
type. New all-type libm functions should just be added to the
appropriate symbol version (currently GLIBC_2.27) for all types, with
such special-case handling for _Float128 versions (and _Float64x as
well in future) waiting until someone actually wants to add support
for _Float128 to an existing platform after a release in which that
platform and a post-2.26 libm function had support but that platform
lacked _Float128 support.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch. Also tested in conjunction
with the remaining changes to enable float128 aliases.
* sysdeps/generic/float128-abi.h: New file.
* sysdeps/ieee754/float128/Versions (FLOAT128_VERSION): Move
non-__prefixed symbols to ....
* math/Versions: ... here. Include <float128-abi.h>.
* stdlib/Versions ... and here. Include <float128-abi.h>
As noted in
<https://sourceware.org/ml/libc-alpha/2012-12/msg00240.html>,
stdlib/Versions and wcsmbs/Versions list some functions as
__strto*_internal and __wcsto*_internal rather than explicitly listing
the symbols to be exported (so any new internal function matching one
of those patterns would be wrongly added to version GLIBC_2.0), which
seems like a bad idea. This patch changes those files to list the
exported symbols explicitly. There are still entries in
sysdeps/nacl/Versions for __nacl_irt_*, but as GLIBC_PRIVATE symbols
that seems less significant.
Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by the patch.
* stdlib/Versions (__strtod_internal): List explicitly, not as
wildcard.
(__strtof_internal): Likewise.
(__strtold_internal): Likewise.
(__strtol_internal): Likewise.
(__strtoll_internal): Likewise.
(__strtoul_internal): Likewise.
(__strtoull_internal): Likewise.
(__strtoq_internal): Likewise.
(__strtouq_internal): Likewise.
* wcsmbs/Versions (__wcstod_internal): Likewise.
(__wcstof_internal): Likewise.
(__wcstold_internal): Likewise.
(__wcstol_internal): Likewise.
(__wcstoll_internal): Likewise.
(__wcstoul_internal): Likewise.
(__wcstoull_internal): Likewise.
ISO/IEC TS 18661-1 adds several functions in the strfrom family to stdlib.
This patch adds strfromd, strfromf, and strfroml. This is being done in
preparation for the new floating-point type, float128. The added functions
convert a floating-point value into a string, with configurable format.
In C++11 18.5.12 says "Objects shall not be destroyed as a
result of calling quick_exit." In C11 quick_exit is silent
about thread object destruction. Therefore to make glibc
C++ compliant we do not call any thread local destructors.
A new regression test verifies the fix.
I will note that C++11 18.5.3 makes it clear that C++
defines additional requirements for _Exit() to prevent it
from executing destructors.
Given that the point of _Exit() is to terminate the process
immediately it makes sense the C and C++ should line up
and avoid calling destructors.
No failures. New regtest passes.
The nan, nanf and nanl functions handle payload strings by doing e.g.:
if (tagp[0] != '\0')
{
char buf[6 + strlen (tagp)];
sprintf (buf, "NAN(%s)", tagp);
return strtod (buf, NULL);
}
This is an unbounded stack allocation based on the length of the
argument. Furthermore, if the argument starts with an n-char-sequence
followed by ')', that n-char-sequence is wrongly treated as
significant for determining the payload of the resulting NaN, when ISO
C says the call should be equivalent to strtod ("NAN", NULL), without
being affected by that initial n-char-sequence. This patch fixes both
those problems by using the __strtod_nan etc. functions recently
factored out of strtod etc. for that purpose, with those functions
being exported from libc at version GLIBC_PRIVATE.
Tested for x86_64, x86, mips64 and powerpc.
[BZ #16961]
[BZ #16962]
* math/s_nan.c (__nan): Use __strtod_nan instead of constructing a
string on the stack for strtod.
* math/s_nanf.c (__nanf): Use __strtof_nan instead of constructing
a string on the stack for strtof.
* math/s_nanl.c (__nanl): Use __strtold_nan instead of
constructing a string on the stack for strtold.
* stdlib/Versions (libc): Add __strtof_nan, __strtod_nan and
__strtold_nan to GLIBC_PRIVATE.
* math/test-nan-overflow.c: New file.
* math/test-nan-payload.c: Likewise.
* math/Makefile (tests): Add test-nan-overflow and
test-nan-payload.
This feature is specifically for the C++ compiler to offload calling
thread_local object destructors on thread program exit, to glibc.
This is to overcome the possible complication of destructors of
thread_local objects getting called after the DSO in which they're
defined is unloaded by the dynamic linker. The DSO is marked as
'unloadable' if it has a constructed thread_local object and marked as
'unloadable' again when all the constructed thread_local objects
defined in it are destroyed.
The terminal output etc is not visible in a core file. The new
libc-internal variable __abort_msg will point to a string with the
message which has been printed before the abort in case abort is
called from inside libc. BZ #10217
cxa_at_quick_exit.
(static-only-routines): Add at_quick_exit.
* stdlib/Versions: Export quick_exit and __cxa_at_quick_exit for
GLIBC_2.10.
* stdlib/quick_exit.c: New file.
* stdlib/at_quick_exit.c: New file.
* stdlib/cxa_at_quick_exit.c: New file.
* stdlib/cxa_atexit.c (__cxa_atexit): Move body to new function. Call
it appropriately.
(__internal_atexit): New function.
(__new_exitfn): Now takes parameter to point to the list to use.
* stdlib/cxa_finalize.c: Remove quick_exit handlers, don't call them.
* stdlib/exit.c (__run_exit_handlers): New function. Split from...
(exit): ...here. Just call __run_exit_handlers appropriately.
* stdlib/exit.h: Declare __quick_exit_funcs, __run_exit_handlers,
__internal_atexit, __cxa_at_quick_exit. Adjust __new_exitfn.
* stdlib/on_exit.c: Adjust call to __new_exitfn.
* stdlib/stdlib.h: Declare at_quick_exit and quick_exit.
* include/stdlib.h: Add hidden_proto for qsort_t and adjust protoype
for _quicksort.
* stdlib/msort.c (qsort): Now a wrapper around qsort_r.
(qsort_r): Renamed from qsort. Take additional parameter and pass it
on as third parameter to compare function and _quicksort.
* stdlib/qsort.c (_quicksort): Take additional parameter and pass on
to the compare function.
* stdlib/Versions [libc] (GLIBC_2.8): Add qsort_r.
* Versions.def: Add GLIBC_2.8 for libc.
2002-07-11 Ulrich Drepper <drepper@redhat.com>
* Versions.def (libc): Add GLIBC_2.3.
* stdlib/Versions [libc] (GLIBC_2.3): Add realpath.
* stdlib/canonicalize.c: Add compatibility version for realpath
and make new code available in GLIBC_2.3.
2001-02-26 Ulrich Drepper <drepper@redhat.com>
* dlfcn/Makefile (distribute): Add modatexit.c and modcxaatexit.c.
(tests): Add tstatexit and tstcxaatexit.
(module-names): Add modatexit and modcxaatexit.
Add rules to build and run tstatexit and tstcxaatexit.
* dlfcn/modatexit.c: New file.
* dlfcn/modcxaatexit.c: New file.
* dlfcn/tstatexit.c: New file.
* dlfcn/tstcxaatexit.c: New file.
* io/Makefile: Pass -DHAVE_DOT_HIDDEN to stat and mknod functions if
.hidden is available.
* io/stat.c: If .hidden is available use it to avoid exporting
functions.
* io/fstat.c: Likewise.
* io/lstat.c: Likewise.
* io/stat64.c: Likewise.
* io/fstat64.c: Likewise.
* io/lstat64.c: Likewise.
* sysdeps/generic/mknod.c: Likewise.
* malloc/mtrace.c: Use __cxa_atexit and not atexit.
* sysdeps/generic/bb_init_func.c: Likewise.
* sysdeps/generic/libc-start.c: Likewise.
* stdlib/atexit.c (__new_exitfn): Move to cxa_atexit.c.
(atexit): Implement using __cxa_atexit.
Use .hidden if availble to avoid exporting atexit.
* stdlib/cxa_atexit.c (__new_exitfn): Moved to here from atexit.c.
* stdlib/Versions: Export __new_exitfn for GLIBC_2.2.3.
* stdlib/Makefile (routines): Add old_atexit.
(static-only-routines): Add atexit.
Pass -DHAVE_DOT_HIDDEN for atexit.c if .hidden is available.
* stdlib/old_atexit.c: New file.
* intl/Makefile: Remove bogus endif.
1998-07-02 21:51 Ulrich Drepper <drepper@cygnus.com>
* Makeconfig: Define list of subdirs as all-subdirs and make subdirs
a copy.
* Makefile: Add rules to generate map files.
(distribute): Remove libc.map, add Versions.def and versions.awk.
* Makerules: Change rules to find map files on common-objpfx.
* elf/Makefile: Likewise.
* md5-crypt/Makefile: Likewise.
* nis/Makefile (libnsl-map): Remove.
* Versions.def: New file.
* versions.awk: New file.
* argp/Versions: New file.
* assert/Versions: New file.
* catgets/Versions: New file.
* csu/Versions: New file.
* ctype/Versions: New file.
* db/Versions: New file.
* debug/Versions: New file.
* dirent/Versions: New file.
* elf/Versions: New file.
* gmon/Versions: New file.
* grp/Versions: New file.
* hesiod/Versions: New file.
* hurd/Versions: New file.
* iconv/Versions: New file.
* inet/Versions: New file.
* intl/Versions: New file.
* io/Versions: New file.
* libio/Versions: New file.
* linuxthreads/Versions: New file.
* locale/Versions: New file.
* login/Versions: New file.
* malloc/Versions: New file.
* math/Versions: New file.
* md5-crypt/Versions: New file.
* misc/Versions: New file.
* nis/Versions: New file.
* nss/Versions: New file.
* posix/Versions: New file.
* pwd/Versions: New file.
* resolv/Versions: New file.
* resource/Versions: New file.
* rt/Versions: New file.
* setjmp/Versions: New file.
* shadow/Versions: New file.
* signal/Versions: New file.
* socket/Versions: New file.
* stdio/Versions: New file.
* stdio-common/Versions: New file.
* stdlib/Versions: New file.
* streams/Versions: New file.
* string/Versions: New file.
* sunrpc/Versions: New file.
* sysdeps/alpha/Versions: New file.
* sysdeps/alpha/fpu/Versions: New file.
* sysdeps/i386/Versions: New file.
* sysdeps/sparc/Versions: New file.
* sysdeps/unix/sysv/Versions: New file.
* sysdeps/unix/sysv/linux/Versions: New file.
* sysdeps/unix/sysv/linux/alpha/Versions: New file.
* sysdeps/unix/sysv/linux/i386/Versions: New file.
* sysdeps/unix/sysv/linux/mips/Versions: New file.
* sysvipc/Versions: New file.
* termios/Versions: New file.
* time/Versions: New file.
* wcsmbs/Versions: New file.
* wctype/Versions: New file.
* libc.map: Removed.
* db/libdb.map: Removed.
* elf/libdl.map: Removed.
* hesiod/libnss_hesiod.map: Removed.
* hurd/libhurduser.map: Removed.
* hurd/libmachuser.map: Removed.
* linuxthreads/libpthread.map: Removed.
* locale/libBrokenLocale.map: Removed.
* login/libutil.map: Removed.
* math/libm.map: Removed.
* md5-crypt/libcrypt.map: Removed.
* nis/libnsl.map: Removed.
* nis/libnsl_compat.map: Removed.
* nis/libnss_nis.map: Removed.
* nis/libnss_nisplus.map: Removed.
* nss/libnss_db.map: Removed.
* nss/libnss_files.map: Removed.
* resolv/libnss_dns.map: Removed.
* resolv/libresolv.map: Removed.
* rt/librt.map: Removed.
* elf/dl-load.c (fillin_rpath): Fix test for trusted directory.
Fix typos.
* elf/rtld.c (process_dl_debug): Recognize 'all'.
(process_envvars): LD_BIND_NOW must be followed by y, Y, or 1.
* sysdeps/generic/elf/backtracesyms.c: Allocate string memory of
correct size.
* sysdeps/unix/sysv/linux/getsysstats.c (get_proc_path): Fix typo
in comment.
