This patch fixes BZ #27777 "fclose does a linear search, takes ages when
many FILE* are opened". Simply put, the master list of opened (FILE*),
namely _IO_list_all, is a singly-linked list. As a consequence, the
removal of a single element is in O(N), which cripples the performance
of fclose(). The patch switches to a doubly-linked list, yielding O(1)
removal. The one padding field in struct _IO_FILE, __pad5, is renamed
to _prevchain for a doubly-linked list. Since fields in struct _IO_FILE
after the _lock field are internal to glibc and opaque to applications.
We can change them as long as the size of struct _IO_FILE is unchanged,
which is checked as the part of glibc ABI with sizes of _IO_2_1_stdin_,
_IO_2_1_stdout_ and _IO_2_1_stderr_.
NB: When _IO_vtable_offset (fp) == 0, copy relocation will cover the
whole struct _IO_FILE. Otherwise, only fields up to the _lock field
will be copied to applications at run-time. It is used to check if
the _prevchain field can be safely accessed.
After opening 2 million (FILE*), the fclose() of 100 of them takes quite
a few seconds without the patch, and under 2 seconds with it on a loaded
machine.
No test is added since there are no functional changes.
Co-Authored-By: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: Alexandre Ferrieux <alexandre.ferrieux@orange.com>
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
It improve fortify checks for sprintf, vsprintf, vsnsprintf, fprintf,
dprintf, asprintf, __asprintf, obstack_printf, gets, fgets,
fgets_unlocked, fread, and fread_unlocked. The runtime checks have
similar support coverage as with GCC.
For function with variadic argument (sprintf, snprintf, fprintf, printf,
dprintf, asprintf, __asprintf, obstack_printf) the fortify wrapper calls
the va_arg version since clang does not support __va_arg_pack.
Checked on aarch64, armhf, x86_64, and i686.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
WG14 decided to use the name C23 as the informal name of the next
revision of the C standard (notwithstanding the publication date in
2024). Update references to C2X in glibc to use the C23 name.
This is intended to update everything *except* where it involves
renaming files (the changes involving renaming tests are intended to
be done separately). In the case of the _ISOC2X_SOURCE feature test
macro - the only user-visible interface involved - support for that
macro is kept for backwards compatibility, while adding
_ISOC23_SOURCE.
Tested for x86_64.
During the review of a GCC analyzer test case, we found most stdio
functions accepting a FILE * argument expect it to be nonnull and just
segfault when the argument is NULL. Add nonnull attribute for them.
fflush and fflush_unlocked are well defined when __stream is NULL so
they are not touched.
For fputs, fgets, fread, fwrite, fprintf, vfprintf, and their unlocked
version, if __stream is empty but there is nothing to read or write,
they did not segfault. But the standard disallow __stream to be empty
here, so nonnull attribute is also added for them. Note that this may
blow up some old code already subtly broken.
Also add __nonnull for _chk variants and __fortify_function versions for
them.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Alejandro Colomar <alx@kernel.org>
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
The change is meant to avoid unwanted PLT entry for the fgets_unlocked
routine when _FORTIFY_SOURCE is set.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Move declarations from libio/bits/stdio.h to existing
libio/bits/stdio2-decl.h. This will enable future use of
__REDIRECT_FORTIFY in place of some __REDIRECT.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
C2x adds binary integer constants starting with 0b or 0B, and supports
those constants for the %i scanf format (in addition to the %b format,
which isn't yet implemented for scanf in glibc). Implement that scanf
support for glibc.
As with the strtol support, 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 input
potentially matching subsequent parts of the scanf format string).
Thus this patch adds 12 new __isoc23_* functions per long double
format (12, 24 or 36 depending on how many long double formats the
glibc configuration supports), with appropriate header redirection
support (generally very closely following that for the __isoc99_*
scanf functions - note that __GLIBC_USE (DEPRECATED_SCANF) takes
precedence over __GLIBC_USE (C2X_STRTOL), so the case of GNU
extensions to C89 continues to get old-style GNU %a and does not get
this new feature). The function names would remain as __isoc23_* even
if C2x ends up published in 2024 rather than 2023.
When scanf %b support is added, I think it will be appropriate for all
versions of scanf to follow C2x rules for inputs to the %b format
(given that there are no compatibility concerns for a new format).
Tested for x86_64 (full glibc testsuite). The first version was also
tested for powerpc (32-bit) and powerpc64le (stdio-common/ and wcsmbs/
tests), and with build-many-glibcs.py.
Compilers may not be able to apply asm redirections to functions after
these functions are used for the first time, e.g. clang 13.
Fix [BZ #27087] by applying all long double-related asm redirections
before using functions in bits/stdio.h.
However, as these asm redirections depend on the declarations provided
by libio/bits/stdio2.h, this header was split in 2:
- libio/bits/stdio2-decl.h contains all function declarations;
- libio/bits/stdio2.h remains with the remaining contents, including
redirections.
This also adds the access attribute to __vsnprintf_chk that was missing.
Tested with build-many-glibcs.py.
Reviewed-by: Paul E. Murphy <murphyp@linux.ibm.com>
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 7061 files FOO.
I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah. I don't
know why I run into these diagnostics whereas others evidently do not.
remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
In _FORTIFY_SOURCE=3, the size expression may be non-constant,
resulting in branches in the inline functions remaining intact and
causing a tiny overhead. Clang (and in future, gcc) make sure that
the -1 case is always safe, i.e. any comparison of the generated
expression with (size_t)-1 is always false so that bit is taken care
of. The rest is avoidable since we want the _chk variant whenever we
have a size expression and it's not -1.
Rework the conditionals in a uniform way to clearly indicate two
conditions at compile time:
- Either the size is unknown (-1) or we know at compile time that the
operation length is less than the object size. We can call the
original function in this case. It could be that either the length,
object size or both are non-constant, but the compiler, through
range analysis, is able to fold the *comparison* to a constant.
- The size and length are known and the compiler can see at compile
time that operation length > object size. This is valid grounds for
a warning at compile time, followed by emitting the _chk variant.
For everything else, emit the _chk variant.
This simplifies most of the fortified function implementations and at
the same time, ensures that only one call from _chk or the regular
function is emitted.
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
In the context of a function definition, the size hints imply that the
size of an object pointed to by one parameter is another parameter.
This doesn't make sense for the fortified versions of the functions
since that's the bit it's trying to validate.
This is harmless with __builtin_object_size since it has fairly simple
semantics when it comes to objects passed as function parameters.
With __builtin_dynamic_object_size we could (as my patchset for gcc[1]
already does) use the access attribute to determine the object size in
the general case but it misleads the fortified functions.
Basically the problem occurs when access attributes are present on
regular functions that have inline fortified definitions to generate
_chk variants; the attributes get inherited by these definitions,
causing problems when analyzing them. For example with poll(fds, nfds,
timeout), nfds is hinted using the __attr_access as being the size of
fds.
Now, when analyzing the inline function definition in bits/poll2.h, the
compiler sees that nfds is the size of fds and tries to use that
information in the function body. In _FORTIFY_SOURCE=3 case, where the
object size could be a non-constant expression, this information results
in the conclusion that nfds is the size of fds, which defeats the
purpose of the implementation because we're trying to check here if nfds
does indeed represent the size of fds. Hence for this case, it is best
to not have the access attribute.
With the attributes gone, the expression evaluation should get delayed
until the function is actually inlined into its destinations.
Disable the access attribute for fortified function inline functions
when building at _FORTIFY_SOURCE=3 to make this work better. The
access attributes remain for the _chk variants since they can be used
by the compiler to warn when the caller is passing invalid arguments.
[1] https://gcc.gnu.org/pipermail/gcc-patches/2021-October/581125.html
Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
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
If build with optimization, stdio.h and sys/stat.h are defining some inlining
functions. This leads to test fails if glibc is build with the following
commands. (Note that the conformtests usually builds without optimization or
other CFLAGS):
<glibc>/configure CC="gcc -O3" --prefix=/usr
make
make subdirs=conform check
- FAIL: conform/XPG4/stdio.h/conform
- FAIL: conform/XPG42/stdio.h/conform
out-files:
...
PASSCOMBINED: Availability of variable optopt
PASSCOMBINED: Type of variable optopt
Namespace violation: "getc_unlocked"
Namespace violation: "getchar_unlocked"
Namespace violation: "putc_unlocked"
Namespace violation: "putchar_unlocked"
FAIL: Namespace of <stdio.h>
----------------------------------------------------------------------------
Total number of tests : 168
Number of failed tests : 1
Number of xfailed tests : 0
Number of skipped tests : 0
- FAIL: conform/POSIX2008/sys/stat.h/conform
out-file:
...
PASSCOMBINED: Availability of function utimensat
PASSCOMBINED: Type of function utimensat
Namespace violation: "mknodat"
FAIL: Namespace of <sys/stat.h>
----------------------------------------------------------------------------
Total number of tests : 97
Number of failed tests : 1
Number of xfailed tests : 0
Number of skipped tests : 0
For getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked in stdio.h,
those are defined "# ifdef __USE_POSIX" instead of "#ifdef __USE_POSIX199506"
for the non-inlining declaration. See also
"Bug 20014 - stdio.h namespace for pre-threads POSIX"
(https://sourceware.org/bugzilla/show_bug.cgi?id=20014).
For mknodat in sys/stat.h, those are defined "# ifdef __USE_ATFILE" instead of
the additional guard "# if defined __USE_MISC || defined __USE_XOPEN_EXTENDED".
Adds the access attribute newly introduced in GCC 10 to the subset of
function declarations that are already covered by _FORTIFY_SOURCE and
that don't have corresponding GCC built-in equivalents.
Reviewed-by: DJ Delorie <dj@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>
All functions that have a format string, which can consume a long double
argument, must have one version for each long double format supported on
a platform. On powerpc64le, these functions currently have two versions
(i.e.: long double with the same format as double, and long double with
IBM Extended Precision format). Support for a third long double format
option (i.e. long double with IEEE long double format) is being prepared
and all the aforementioned functions now have a third version (not yet
exported on the master branch, but the code is in).
For these functions to get selected (during build time), references to
them in user programs (or dependent libraries) must get redirected to
the aforementioned new versions of the functions. This patch installs
the header magic required to perform such redirections.
Notice, however, that since the redirections only happen when
__LONG_DOUBLE_USES_FLOAT128 is set to 1, and no platform (including
powerpc64le) currently does it, no redirections actually happen.
Redirections and the exporting of the new functions will happen at the
same time (when powerpc64le adds ldbl-128ibm-compat to their Implies.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.ibm.com>
Reviewed-by: Paul E. Murphy <murphyp@linux.vnet.ibm.com>
The only difference between noncompliant and C99-compliant scanf is
that the former accepts the archaic GNU extension '%as' (also %aS and
%a[...]) meaning to allocate space for the input string with malloc.
This extension conflicts with C99's use of %a as a format _type_
meaning to read a floating-point number; POSIX.1-2008 standardized
equivalent functionality using the modifier letter 'm' instead (%ms,
%mS, %m[...]).
The extension was already disabled in most conformance modes:
specifically, any mode that doesn't involve _GNU_SOURCE and _does_
involve either strict conformance to C99 or loose conformance to both
C99 and POSIX.1-2001 would get the C99-compliant scanf. With
compilers new enough to use -std=gnu11 instead of -std=gnu89, or
equivalent, that includes the default mode.
With this patch, we now provide C99-compliant scanf in all
configurations except when _GNU_SOURCE is defined *and*
__STDC_VERSION__ or __cplusplus (whichever is relevant) indicates
C89/C++98. This leaves the old scanf available under e.g. -std=c89
-D_GNU_SOURCE, but removes it from e.g. -std=gnu11 -D_GNU_SOURCE (it
was already not present under -std=gnu11 without -D_GNU_SOURCE) and
from -std=gnu89 without -D_GNU_SOURCE.
There needs to be an internal override so we can compile the
noncompliant scanf itself. This is the same problem we had when we
removed 'gets' from _GNU_SOURCE and it's dealt with the same way:
there's a new __GLIBC_USE symbol, DEPRECATED_SCANF, which defaults to
off under the appropriate conditions for external code, but can be
overridden by individual files within stdio.
We also run into problems with PLT bypass for internal uses of sscanf,
because libc_hidden_proto uses __REDIRECT and so does the logic in
stdio.h for choosing which implementation of scanf to use; __REDIRECT
isn't transitive, so include/stdio.h needs to bridge the gap with a
macro. As far as I can tell, sscanf is the only function in this
family that's internally called by unrelated code.
Finally, there are several tests in stdio-common that use the
extension. bug21.c is a regression test for a crash; it still
exercises the relevant code when changed to use %ms instead of %as.
scanf14.c through scanf17.c are more complicated since they are
actually testing the subtleties of the extension - under what
circumstances is 'a' treated as a modifier letter, etc. I changed all
of them to use %ms instead of %as as well, but duplicated scanf14.c
and scanf16.c as scanf14a.c and scanf16a.c. These still use %as and
are compiled with -std=gnu89 to access the old extension. A bunch of
diagnostic overrides and manual workarounds for the old stdio.h
behavior become unnecessary. Yay!
* include/features.h (__GLIBC_USE_DEPRECATED_SCANF): New __GLIBC_USE
parameter. Only use deprecated scanf when __USE_GNU is defined
and __STDC_VERSION__ is less than 199901L or __cplusplus is less
than 201103L, whichever is relevant for the language being compiled.
* libio/stdio.h, libio/bits/stdio-ldbl.h: Decide whether to redirect
scanf, fscanf, sscanf, vscanf, vfscanf, and vsscanf to their
__isoc99_ variants based only on __GLIBC_USE (DEPRECATED_SCANF).
* wcsmbs/wchar.h: wcsmbs/bits/wchar-ldbl.h: Likewise for
wscanf, fwscanf, swscanf, vwscanf, vfwscanf, and vswscanf.
* libio/iovsscanf.c
* libio/fwscanf.c
* libio/iovswscanf.c
* libio/swscanf.c
* libio/vscanf.c
* libio/vwscanf.c
* libio/wscanf.c
* stdio-common/fscanf.c
* stdio-common/scanf.c
* stdio-common/vfscanf.c
* stdio-common/vfwscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-compat.c
* sysdeps/ieee754/ldbl-opt/nldbl-fscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-fwscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-iovfscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-scanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-sscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-swscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vfscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vfwscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vsscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vswscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-vwscanf.c
* sysdeps/ieee754/ldbl-opt/nldbl-wscanf.c:
Override __GLIBC_USE_DEPRECATED_SCANF to 1.
* stdio-common/sscanf.c: Likewise. Remove ldbl_hidden_def for __sscanf.
* stdio-common/isoc99_sscanf.c: Add libc_hidden_def for __isoc99_sscanf.
* include/stdio.h: Provide libc_hidden_proto for __isoc99_sscanf,
not sscanf.
[!__GLIBC_USE (DEPRECATED_SCANF)]: Define sscanf as __isoc99_scanf
with a preprocessor macro.
* stdio-common/bug21.c, stdio-common/scanf14.c:
Use %ms instead of %as, %mS instead of %aS, %m[] instead of %a[];
remove DIAG_IGNORE_NEEDS_COMMENT for -Wformat.
* stdio-common/scanf16.c: Likewise. Add __attribute__ ((format (scanf)))
to xscanf, xfscanf, xsscanf.
* stdio-common/scanf14a.c: New copy of scanf14.c which still uses
%as, %aS, %a[]. Remove DIAG_IGNORE_NEEDS_COMMENT for -Wformat.
* stdio-common/scanf16a.c: New copy of scanf16.c which still uses
%as, %aS, %a[]. Add __attribute__ ((format (scanf))) to xscanf,
xfscanf, xsscanf.
* stdio-common/scanf15.c, stdio-common/scanf17.c: No need to
override feature selection macros or provide definitions of u_char etc.
* stdio-common/Makefile (tests): Add scanf14a and scanf16a.
(CFLAGS-scanf15.c, CFLAGS-scanf17.c): Remove.
(CFLAGS-scanf14a.c, CFLAGS-scanf16a.c): New. Compile these files
with -std=gnu89.
This entirely mechanical (except for some indentation fixups) patch
replaces all uses of _IO_file_flags with _flags and removes the #define.
Installed stripped libraries and executables are unchanged by this patch.
* libio/libio.h (_IO_file_flags): Remove macro.
All uses changed to _flags.
We can't go very far with libio cleanups as long as we still have
_IO_MTSAFE_IO, and I am not tackling that in this patch series,
but we can at least make the maze of stdio-related headers a
little less complicated.
In this patch, libio.h moves back out of bits/ into the top level of
the libio subdirectory, and is merged with libio/bits/libio-ldbl.h
(which also used to be installed) and include/libio.h. Since almost
no files include libio.h directly, this is quite straightforward.
libio.h is now always used with _LIBC defined, so all of the _LIBC ||
_GLIBCPP_USE_WCHAR_T conditionals are unnecessary. Similarly, the
ifdef nest surrounding the definition of _IO_fwide_maybe_incompatible
can collapse down to a single SHLIB_COMPAT check. I also took the
opportunity to add some checks for configuration botches to libio.h.
Installed stripped libraries are unchanged by this patch.
* libio/bits/libio.h: Move back to libio/libio.h and adjust
multiple-include guard to match.
Merge contents of libio/bits/libio-ldbl.h and include/libio.h
into this file.
Remove preprocessor conditionals that are always true and/or
redundant to other preprocessor conditionals in the same nest.
Include shlib-compat.h unconditionally.
Error out if _LIBC is not defined, or if _ISOMAC is defined,
or if _IO_MTSAFE_IO is defined but _IO_lock_t_defined is not
defined after including stdio.h.
Use __BEGIN_DECLS/__END_DECLS.
* libio/bits/libio-ldbl.h, include/bits/libio.h: Delete file.
* include/stdio.h, libio/iolibio.h, libio/libioP.h: Include
libio.h as <libio/libio.h> rather than as <bits/libio.h>.
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.
The getc and putc macros in the public stdio.h expand to call _IO_getc
and _IO_putc respectively. As _IO_getc, fgetc, and getc are all aliases
for the same function, and _IO_putc, fputc, and putc are also all aliases
for the same function, the macros are pointless. The C standard does
not require getc and putc to be macros, so let's just not have macros.
All four symbols are exported from libc.so at the same, ancient symbol
version, so there should be no risks for binary compatibility. Similarly,
the getchar and putchar inlines in bits/stdio.h forward to getc and putc
instead of their _IO_ aliases.
As a change from longstanding historical practice, this does seem
like it might break _something_, so there is a note in NEWS, which
is also a convenient place to advise people that if they thought getc
and putc had reduced per-character overhead they should consider using
getc_unlocked and putc_unlocked instead. (These are also not macros,
but when optimizing, they are inlines.)
* libio/stdio.h: Don't define getc or putc as macros.
* libio/bits/stdio.h (getchar, putchar): Use getc and putc,
not _IO_getc and _IO_putc.
The patch which moved libio.h proper into the bits directory also
changed the name of its guard macro, and I neglected to check whether
anything depended on that name. It turns out that there is a
conditionally-used bits header that looks at it; this broke the libgcc
build on at least sparc64-*-* and sparcv9-*-*.
* libio/bits/libio-ldbl.h: Correct check for improper
inclusion. Add own multiple include guard.
libio.h was originally the header for a set of supported GNU
extensions, but they have not been maintained as such in many years,
they are now standing in the way of improvements to stdio, and we
don't think there are any remaining external users. _G_config.h was
never intended for public use, but predates the bits convention.
Move both of these headers into the bits directory and provide stubs
at top level which issue deprecation warnings.
The contents of (bits/)libio.h and (bits/)_G_config.h are still
exposed to external software via stdio.h; changing that requires more
complex surgery than I have time to attempt right now.
* libio/libio.h, libio/_G_config.h: New stub headers which issue a
deprecation warning and then include <bits/libio.h>, <bits/_G_config.h>
respectively.
* libio/libio.h: Rename the original version of this file to
libio/bits/libio.h. Error out if not included by stdio.h or the
stub libio.h.
* include/libio.h: Move to include/bits. Forward to libio/bits/libio.h.
* sysdeps/generic/_G_config.h: Move to top-level bits/. Error out
if not included by bits/libio.h or the stub _G_config.h.
* sysdeps/unix/sysv/linux/_G_config.h: Move to
sysdeps/unix/sysv/linux/bits. Error out if not included by
bits/libio.h or the stub _G_config.h.
* libio/stdio.h: Include bits/libio.h, not libio.h.
* libio/Makefile: Install bits/libio.h and bits/_G_config.h as
well as libio.h and _G_config.h.
* csu/init.c, libio/fmemopen.c, libio/iolibio.h, libio/oldfmemopen.c
* libio/strfile.h, stdio-common/vfscanf.c
* sysdeps/pthread/flockfile.c, sysdeps/pthread/funlockfile.c
Include stdio.h, not _G_config.h nor libio.h.
* libio/iofgetpos.c: Also rename fgetpos64 out of the way.
* libio/iofsetpos.c: Also rename fsetpos64 out of the way.
* scripts/check-installed-headers.sh: Skip libio.h and _G_config.h.
wint_t is a little finicky because it might be defined by stddef.h, which
belongs to the compiler.
In addition to the _types_, a bunch of other declarations shared between
wctype.h and wchar.h are factored out to their own header.
* libio/bits/types/FILE.h, libio/bits/types/__FILE.h
* wcsmbs/bits/types/mbstate_t.h, wcsmbs/bits/types/__mbstate_t.h
* wcsmbs/bits/types/wint_t.h: New single-type definition files.
* wctype/bits/wctype-wchar.h: New file holding declarations shared
between wctype.h and wchar.h.
* libio/Makefile, wcsmbs/Makefile, wctype/Makefile:
Install them.
* include/bits/types/FILE.h, include/bits/types/__FILE.h
* include/bits/types/mbstate_t.h, include/bits/types/__mbstate_t.h
* include/bits/types/wint_t.h, include/bits/wcsmbs-wchar.h:
New wrappers.
* include/stdio.h, include/wchar.h, include/wctype.h:
No need to handle __need macros.
* grp/grp.h, gshadow/gshadow.h, hurd/hurd.h, iconv/gconv.h
* libio/stdio.h, mach/mach.h, misc/mntent.h, pwd/pwd.h
* shadow/shadow.h, stdio-common/printf.h, wcsmbs/uchar.h
* wcsmbs/wchar.h, wctype/wctype.h
* sysdeps/generic/_G_config.h, sysdeps/unix/sysv/linux/_G_config.h
Use the new files instead of __need macros.
glibc headers include some code (not particularly consistent or
systematic) to put various declarations in C++ namespaces std and
__c99, if _GLIBCPP_USE_NAMESPACES is defined.
As noted in <https://gcc.gnu.org/ml/libstdc++/2017-03/msg00025.html>,
this macro was removed from libstdc++ in 2000. I don't expect
compilation with such old versions of libstdc++ to work with current
glibc headers anyway (whereas old *binaries* are expected to stay
working with current glibc); this patch (which should be a no-op with
any libstdc++ version postdating that removal) removes all this code
from the glibc headers.
The begin-end-check.pl test, whose comments say it is about checking
these namespace macro calls, is also removed. The code in that test
would have covered __BEGIN_DECLS / __END_DECLS as well, but if those
weren't properly matched it would show up with the
check-installed-headers-cxx tests, so I don't think there is an actual
use for keeping begin-end-check.pl with the namespace code removed.
Tested for x86_64 and x86 (testsuite, and that installed stripped
shared libraries are unchanged by the patch).
* misc/sys/cdefs.h (__BEGIN_NAMESPACE_STD): Remove macro.
(__END_NAMESPACE_STD): Likewise.
(__USING_NAMESPACE_STD): Likewise.
(__BEGIN_NAMESPACE_C99): Likewise.
(__END_NAMESPACE_C99): Likewise.
(__USING_NAMESPACE_C99): Likewise.
* math/math.h (_Mdouble_BEGIN_NAMESPACE): Do not define and
undefine macro.
(_Mdouble_END_NAMESPACE): Likewise.
* ctype/ctype.h: Do not handle C++ namespaces.
* libio/bits/stdio-ldbl.h: Likewise.
* libio/stdio.h: Likewise.
* locale/locale.h: Likewise.
* math/bits/mathcalls.h: Likewise.
* setjmp/setjmp.h: Likewise.
* signal/signal.h: Likewise.
* stdlib/bits/stdlib-float.h: Likewise.
* stdlib/bits/stdlib-ldbl.h: Likewise.
* stdlib/stdlib.h: Likewise.
* string/string.h: Likewise.
* sysdeps/x86/fpu/bits/mathinline.h: Likewise.
* time/bits/types/clock_t.h: Likewise.
* time/bits/types/struct_tm.h: Likewise.
* time/bits/types/time_t.h: Likewise.
* time/time.h: Likewise.
* wcsmbs/bits/wchar-ldbl.h: Likewise.
* wcsmbs/uchar.h: Likewise.
* wcsmbs/wchar.h: Likewise.
[_GLIBCPP_USE_NAMESPACES] (wint_t): Remove conditional definition.
* wctype/wctype.h: Do not handle C++ namespaces.
* scripts/begin-end-check.pl: Remove.
* Makefile (installed-headers): Likewise.
(tests-special): Do not add $(objpfx)begin-end-check.out.
($(objpfx)begin-end-check.out): Remove.
gets has the dubious honor of being the only C89 library feature that
has been completely removed from the current C and C++ standards.
glibc follows suit by not declaring it in _GNU_SOURCE mode either,
but it remains present in older compatibility modes. Internally,
two test cases need to see stdio.h make the declaration, but all our
internal code is of course compiled under _GNU_SOURCE. This is currently
kludged by duplicating the gets declaration, fortify wrapper and all,
in include/stdio.h. Also, the conditional in the public headers for
deciding when to declare gets is complicated and repeated in two places.
This patch adds a new macro to features.h that encapsulates the
complicated rule for when to declare gets. stdio.h and bits/stdio2.h
then simply test __GLIBC_USE (DEPRECATED_GETS), and instead of having
a duplicate gets declaration in include/stdio.h, debug/tst-chk1.c and
stdio-common/tst-gets.c can force gets to be declared.
* include/features.h (__GLIBC_USE_DEPRECATED_GETS): New macro.
* libio/stdio.h, libio/bits/stdio2.h: Condition gets on
__GLIBC_USE (DEPRECATED_GETS). Update comments to indicate
gets was removed from C++ in C++14.
* include/stdio.h: Remove redundant declaration of gets.
* debug/tst-chk1.c, stdio-common/tst-gets.c: Force gets to
be declared, since we are testing it.
* stdio-common/Makefile (tst-gets.c): Compile with
-Wno-deprecated-declarations.
* debug/Makefile (tst-chk1.c, tst-chk2.c, tst-chk3.c, tst-chk4.cc)
(tst-chk5.cc, tst-chk6.cc, tst-lfschk1.c, tst-lfschk2.c)
(tst-lfschk3.c, tst-lfschk4.cc, tst-lfschk5.cc, tst-lfschk6.cc):
Compile with -Wno-deprecated-declarations.
with __warning__/__error__ attributes.
(__warnattr): Define.
* stdlib/bits/stdlib.h (__realpath_chk_warn, __ptsname_r_chk_warn,
__mbstowcs_chk_warn, __wcstombs_chk_warn): New aliases with
__warnattr.
(realpath, ptsname_r, mbstowcs, wcstombs): Call __*_chk_warn instead
of __*_chk if compile time detectable overflow is found.
* libio/bits/stdio2.h (__fgets_chk_warn, __fread_chk_warn,
__fgets_unlocked_chk_warn, __fread_unlocked_chk_warn): New aliases
with __warnattr.
(fgets, fread, fgets_unlocked, fread_unlocked): Call __*_chk_warn
instead of __*_chk if compile time detectable overflow is found.
(__gets_alias): Rename to...
(__gets_warn): ... this. Add __warnattr.
(gets): Call __gets_warn instead of __gets_alias.
* socket/bits/socket2.h (__recv_chk_warn, __recvfrom_chk_warn): New
aliases with __warnattr.
(recv, recvfrom): Call __*_chk_warn instead of __*_chk if compile
time detectable overflow is found.
* posix/bits/unistd.h (__read_chk_warn, __pread_chk_warn,
__pread64_chk_warn, __readlink_chk_warn, __readlinkat_chk_warn,
__getcwd_chk_warn, __confstr_chk_warn, __getgroups_chk_warn,
__ttyname_r_chk_warn, __getlogin_r_chk_warn, __gethostname_chk_warn,
__getdomainname_chk_warn): New aliases with __warnattr.
(read, pread, pread64, readlink, readlinkat, getcwd, confstr,
getgroups, ttyname_r, getlogin_r, gethostname, getdomainname): Call
__*_chk_warn instead of __*_chk if compile time detectable overflow
is found.
(__getgroups_chk): Rename argument to __listlen from listlen.
(__getwd_alias): Rename to...
(__getwd_warn): ... this. Add __warnattr.
(getwd): Call __getwd_warn instead of __getwd_alias.
* wcsmbs/bits/wchar2.h (__wmemcpy_chk_warn, __wmemmove_chk_warn,
__wmempcpy_chk_warn, __wmemset_chk_warn, __wcsncpy_chk_warn,
__wcpncpy_chk_warn, __fgetws_chk_warn, __fgetws_unlocked_chk_warn,
__mbsrtowcs_chk_warn, __wcsrtombs_chk_warn, __mbsnrtowcs_chk_warn,
__wcsnrtombs_chk_warn): New aliases with __warnattr.
(wmemcpy, wmemmove, wmempcpy, wmemset, mbsrtowcs, wcsrtombs,
mbsnrtowcs, wcsnrtombs): Call __*_chk_warn instead of __*_chk if
compile time detectable overflow is found.
(wcsncpy, wcpncpy): Likewise. For constant __n fix check whether
to use __*_chk or not.
(fgetws, fgetws_unlocked): Divide __bos by sizeof (wchar_t), both
in comparisons which function should be called and in __*_chk*
arguments. Call __*_chk_warn instead of __*_chk if compile time
detectable overflow is found.
(swprintf, vswprintf): Divide __bos by sizeof (wchar_t) in
__*_chk argument.
* debug/tst-chk1.c (do_test): Add a few more tests.
