Adding %b support to vfprintf for parity with kernel space requires
more discussion/review.
In particular, many parties were concerned over introducing a
non-standard format qualifier to *printf(3) which didn't already
exist in other OSes, e.g. Linux, thus making code which used %b
harder to port to other operating systems.
Requested by: many
This is a direct port of the kernel %b format.
I'm unclear on if (more) non-portable printf extensions will be a
problem. I think it's desirable to have userspace formats include all
kernel formats, but there may be competing goals I'm not aware of.
Reviewed by: no one, unfortunately
Sponsored by: Dell EMC Isilon
Differential Revision: https://reviews.freebsd.org/D8426
functions.
__SERR is for user and the rest of stdio code do not check it
for error sensing internally, only set it.
In vf(w)printf.c here it is more easy to save __SERR, clear and restore it.
(i.e., the return value would overflow), set errno to EOVERFLOW
and return an error. This improves the chances that buggy
applications -- for instance, ones that pass in a negative integer
as the size due to a bogus calculation -- will fail in safe ways.
Returning an error in these situations is specified by POSIX, but
POSIX appears to have an off-by-one error that isn't duplicated in
this change.
Previously, some of these functions would silently cap the size at
INT_MAX+1, and others would exit with an error after writing more
than INT_MAX characters.
PR: 39256
MFC after: 2 weeks
load of _l suffixed versions of various standard library functions that use
the global locale, making them take an explicit locale parameter. Also
adds support for per-thread locales. This work was funded by the FreeBSD
Foundation.
Please test any code you have that uses the C standard locale functions!
Reviewed by: das (gdtoa changes)
Approved by: dim (mentor)
by *sprintf(), etc.
- Explicitly initialize _fl_mutex to PTHREAD_MUTEX_INITIALIZER for all FILE
objects. This is currently a nop on FreeBSD, but is import for other
platforms (or in the future) where PTHREAD_MUTEX_INITIALIZER is not simply
zero.
PR: threads/141198
Reported by: Jeremy Huddleston @ Apple
MFC after: 2 weeks
The integer thousands' separator code is rewritten in order to
avoid having to preallocate a buffer for the largest possible
digit string with the most possible instances of the longest
possible multibyte thousands' separator. The new version inserts
thousands' separators for integers using the same code as floating point.
sets up a fake buffered FILE and then effectively calls itself
recursively. Unfortunately, gcc doesn't know how to do tail call
elimination in this case, and actually makes things worse by
inlining __sbprintf(). This means that f[w]printf() to stderr was
allocating about 5k of stack on 64-bit platforms, much of which was
never used.
I've reorganized things to eliminate the waste. In addition to saving
some stack space, this improves performance in my tests by anywhere
from 5% to 17% (depending on the test) when -fstack-protector is
enabled. I found no statistically significant performance difference
when stack protection is turned off. (The tests redirected stderr to
/dev/null.)
slightly less evil inline functions, and move the buffering state into
a struct. This will make it possible for helper routines to produce
output for printf() directly, making it possible to untangle the code
somewhat.
In wprintf(), use the same buffering mechanism to reduce diffs to
printf(). This has the side-effect of causing wprintf() to catch write
errors that it previously ignored.
by moving the positional argument handling code to a new file,
printf-pos.c, and moving common definitions to printflocal.h.
No functional change intended.
In particular, encapsulate the state of the type table in a struct,
and add inline functions to initialize, free, and manipulate that
state. This replaces some ugly macros that made proper error handling
impossible.
While here, remove an unneeded test for NULL and a variable that is
initialized (many times!) but never used. The compiler didn't catch
these because of rampant use of the same variable to mean different
things in different places.
This commit should not cause any changes in functionality.
__sFILE. This was supposed to be done in 6.0. Some notes:
- Where possible I restored the various lines to their pre-__sFILEX state.
- Retire INITEXTRA() and just initialize the wchar bits (orientation and
mbstate) explicitly instead. The various places that used INITEXTRA
didn't need the locking fields or _up initialized. (Some places needed
_up to exist and not be off the end of a NULL or garbage pointer, but
they didn't require it to be initialized to a specific value.)
- For now, stdio.h "knows" that pthread_t is a 'struct pthread *' to
avoid namespace pollution of including all the pthread types in stdio.h.
Once we remove all the inlines and make __sFILE private it can go back
to using pthread_t, etc.
- This does not remove any of the inlines currently and does not change
any of the public ABI of 'FILE'.
MFC after: 1 month
Reviewed by: peter
on probationary terms: it may go away again if it transpires it is
a bad idea.
This extensible printf version will only be used if either
environment variable USE_XPRINTF is defined
or
one of the extension functions are called.
or
the global variable __use_xprintf is set greater than zero.
In all other cases our traditional printf implementation will
be used.
The extensible version is slower than the default printf, mostly
because less opportunity for combining I/O operation exists when
faced with extensions. The default printf on the other hand
is a bad case of spaghetti code.
The extension API has a GLIBC compatible part and a FreeBSD version
of same. The FreeBSD version exists because the GLIBC version may
run afoul of our FILE * locking in multithreaded programs and it
even further eliminate the opportunities for combining I/O operations.
Include three demo extensions which can be enabled if desired: time
(%T), hexdump (%H) and strvis (%V).
%T can format time_t (%T), struct timeval (%lT) and struct timespec (%llT)
in one of two human readable duration formats:
"%.3llT" -> "20349.245"
"%#.3llT" -> "5h39m9.245"
%H will hexdump a sequence of bytes and takes a pointer and a length
argument. The width specifies number of bytes per line.
"%4H" -> "65 72 20 65"
"%+4H" -> "0000 65 72 20 65"
"%#4H" -> "65 72 20 65 |er e|"
"%+#4H" -> "0000 65 72 20 65 |er e|"
%V will dump a string in strvis format.
"%V" -> "Hello\tWor\377ld" (C-style)
"%0V" -> "Hello\011Wor\377ld" (octal)
"%+V" -> "Hello%09Wor%FFld" (http-style)
Tests, comments, bugreports etc are most welcome.
For some denormalized long double values, a bug in __hldtoa() (called
from *printf()'s %A format) results in a base 16 digit being rounded
up from 0xf to 0x10.
When this digit is subsequently converted to string format, an index
of 10 reaches past the end of the uppper-case hex/char array, picking
up whatever the code segment happen to contain at that address.
This mostly seem to be some character from the upper half of the
byte range.
When using the %a format instead of %A, the first character past
the end of the lowercase hex/char table happens to be index 0 in
the uppercase hex/char table hextable and therefore the string
representation features a '0', which is supposedly correct.
This leads me to belive that the proper fix _may_ be as simple as
masking all but the lower four bits off after incrementing a hex-digit
in libc/gdtoa/_hdtoa.c:roundup(). I worry however that the upper
bit in 0x10 indicates a carry not carried.
Until das@ or bde@ finds time to visit this issue, extend the
hexdigit arrays with a 17th index containing '?' so that we get a
invalid but consistent and printable output in both %a and %A formats
whenever this bug strikes.
This unmasks the bug in the %a format therefore solving the real
issue may both become easier and more urgent.
Possibly related to: PR 85080
With help by: bde@
floating-point support, remove default definition of FLOATING_POINT
from the source, and change the compile-time option to
NO_FLOATING_POINT.
- Remove the HEXFLOAT option. It saves an insignificant amount of
space (<0.1% of the size of libc on i386) and complicates vfprintf()
and checkfmt().
after their change from an array of char to an array of enum.
This fixes problems that occurred when using positional arguments in
format strings, particularly with more than STATIC_ARG_TBL_SIZE (8)
of them.
PR: 65841
Submitted by: Steven Smith (mostly)
these are not fully implemented and ifdef'd out, the bugs have
never manifested themselves. Specifically:
- Fix a memory leak in the case where %a follows another
floating-point format.
- Make the %a/%A code behave like %e/%E with respect to
precision.
- It is no longer valid to assume that '-' and '0x' are
mutually exclusive.
- Address other minor issues.
%f and sufficiently short %g specifiers where the precision was
explicitly zero, no '#' flag was specified, and the floating point
argument was > 0 and <= 0.5. While at it, add some comments to better
explain the relevant bits of code.
Noticed by: Christoph Kukulies <kuku@physik.rwth-aachen.de>
be printed.
- Fix %f conversions where the number of significant digits is < expt.
This would be a one-line change were it not for thousands separators.
Noticed by tjr.
- Remove some unnecessary code in the parsing of precision specifiers.
- We used to round long double arguments to double. Now we print
them properly.
- Bugs involving '%F', corner cases of '#' and 'g' format
specifiers, and the '.*' precision specifier have been
fixed.
- Added support for the "'" specifier to print thousands' grouping
characters in a locale-dependent manner.
- Implement the __vfprintf() side of hexadecimal floating point
support. All that is still needed is a routine to convert the
mantissa to hex digits one nibble at a time in the style of ultoa().
Reviewed by: silence on standards@
- __vfprintf()'s 'buf' has never been used for floating point, so
don't define it in terms of (incorrect) constants describing
floating point numbers. The actual size needed depends on
sizeof(uintmax_t) and locale details, so I slightly overestimated.
- We don't need a 308-character buffer to store the string "308".
With long doubles and %a we need more than three characters, though.
dtoa() is buggy. The bug would cause incorrect output to be
generated when format strings such as '%5.0f' were used with
nonzero numbers whose magnitude is less than 1.
Reported by: df(1) by way of periodic(8)
Reviewed by: mike
package, a more recent, generalized set of routines. Among the
changes:
- Declare strtof() and strtold() in stdlib.h.
- Add glue to libc to support these routines for all kinds
of ``long double''.
- Update printf() to reflect the fact that dtoa works slightly
differently now.
As soon as I see that nothing has blown up, I will kill
src/lib/libc/stdlib/strtod.c. Soon printf() will be able
to use the new routines to output long doubles without loss
of precision, but numerous bugs in the existing code must
be addressed first.
Reviewed by: bde (briefly), mike (mentor), obrien
