As reported in bug 32045, it's incorrect for strtod/nan functions to
set errno based on overflowing payload (strtod should only set errno
for overflow / underflow of its actual result, and potentially if
nothing in the string can be parsed as a number at all; nan should be
a pure function that never sets it). Save and restore errno around
the internal strtoull call and add associated test coverage.
Tested for x86_64.
There are two separate sets of tests of NaN payloads in glibc:
* libm-test-{get,set}payload* verify that getpayload, setpayload,
setpayloadsig and __builtin_nan functions are consistent in their
payload handling.
* test-nan-payload verifies that strtod-family functions and the
not-built-in nan functions are consistent in their payload handling.
Nothing, however, connects the two sets of functions (i.e., verifies
that strtod / nan are consistent with getpayload / setpayload /
__builtin_nan).
Improve test-nan-payload to check actual payload value with getpayload
rather than just verifying that the strtod and nan functions produce
the same NaN. Also check that the NaNs produced aren't signaling and
extend the tests to cover _FloatN / _FloatNx.
Tested for x86_64.
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
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
As noted in bug 21607, NO_LONG_DOUBLE conditionals in libm tests are
no longer effective. For most this is harmless - they were only
present because of long double functions not being declared with _LIBC
defined, and _LIBC is no longer defined for building most tests. For
the few where this is actually relevant to the test, testing
LDBL_MANT_DIG > DBL_MANT_DIG is more appropriate as that limits the
test to public APIs. This patch fixes the tests accordingly.
Tested for x86_64 and arm.
[BZ #21607]
* math/basic-test.c [!NO_LONG_DOUBLE]: Change conditionals to
[LDBL_MANT_DIG > DBL_MANT_DIG].
* math/bug-nextafter.c [!NO_LONG_DOUBLE]: Remove conditionals.
* math/bug-nexttoward.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-math-isinff.cc [!NO_LONG_DOUBLE]: Likewise.
* math/test-math-iszero.cc [!NO_LONG_DOUBLE]: Likewise.
* math/test-nan-overflow.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-nan-payload.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-nearbyint-except-2.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-nearbyint-except.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-powl.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-signgam-finite-c99.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-signgam-finite.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-signgam-main.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-snan.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-tgmath-ret.c [!NO_LONG_DOUBLE]: Likewise.
* math/test-tgmath.c: Include <float.h>.
[!NO_LONG_DOUBLE]: Change conditionals to [LDBL_MANT_DIG >
DBL_MANT_DIG].
* math/test-tgmath2.c: Include <float.h>.
[!NO_LONG_DOUBLE]: Change conditionals to [LDBL_MANT_DIG >
DBL_MANT_DIG].
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.
