The lgamma inline functions in bits/math-finite.h do not set signgam
if __USE_ISOC99, even when other feature test macros mean a standard
such as XSI POSIX is selected for which it should be set. (This is
essentially the opposite issue to bug 15421, the out-of-line versions
setting signgam even when they shouldn't.)
This patch fixes those functions to use __USE_MISC || __USE_XOPEN as
the condition for when to set signgam, since it's the condition for
when math.h declares signgam. The legacy gamma* names are only
declared at all if __USE_MISC || __USE_XOPEN, so they just set signgam
unconditionally.
Tests for certain standards or not using _GNU_SOURCE cannot use
test-skeleton.c (this is a known issue noted on the wiki todo list).
Thus, the new tests that signgam remains not set in ISO C modes do not
use test-skeleton.c. They also define _ISOMAC to avoid running into
declarations in the internal include/ headers that only work in
_GNU_SOURCE mode.
Tested for x86_64 and x86.
[BZ #19211]
* math/bits/math-finite.h (lgamma): Set signgam if [__USE_MISC ||
__USE_XOPEN], not if [!__USE_ISOC99].
(lgammaf): Likewise.
(lgammal): Likewise.
(gamma): Set signgam unconditionally, not if [!__USE_ISOC99].
(gammaf): Likewise.
(gammal): Likewise.
* math/test-signgam-finite-c11.c: New file.
* math/test-signgam-finite-c99.c: Likewise.
* math/test-signgam-finite.c: Likewise.
* math/Makefile (tests): Add test-signgam-finite,
test-signgam-finite-c99 and test-signgam-finite-c11.
(CFLAGS-test-signgam-finite.c): New variable.
(CFLAGS-test-signgam-finite-c99.c): Likewise.
(CFLAGS-test-signgam-finite-c11.c): Likewise.
bits/math-finite.h maps ldexp functions to corresponding scalbn
functions. This is (a) a namespace bug for C90, which has ldexp but
not scalbn, and (b) in any case useless, since the ldexp and scalbn
functions have identical semantics (for floating-point types with
radix 2), and since the fix for bug 6803 are actually aliases
(presumably the mapping was based around the old bug of scalbn not
setting errno). This patch removes the bogus redirections.
Tested for x86_64 and x86.
[BZ #19209]
* math/bits/math-finite.h (ldexp): Remove declaration.
(ldexpf): Likewise.
(ldexpl): Likewise.
bits/math-finite.h declares -ffinite-math-only variants of various
functions under conditions not matching those under which the normal
versions are declared.
* math.h only ever includes bits/mathcalls.h to declare float and long
double functions if __USE_ISOC99, but bits/math-finite.h declares
some float functions regardless (long double ones are conditioned on
__MATH_DECLARE_LDOUBLE). (For C90 functions this isn't a
conformance bug because C90 reserves the float and long double
names, but is still contrary to good glibc practice. For some other
functions in older XSI standards it *is* a conformance bug.)
* Some functions are defined as inlines using lgamma_r functions under
conditions where those lgamma_r functions are not themselves
declared.
* hypot is declared under __USE_XOPEN || __USE_ISOC99 in
bits/mathcalls.h, __USE_ISOC99 only in bits/math-finite.h.
* float and long double versions of Bessel functions should be limited
to __USE_MISC (as in bug 18977).
* gamma should not be declared for __USE_XOPEN2K (as in bug 18967).
* remainder should be restricted to __USE_XOPEN_EXTENDED ||
__USE_ISOC99, not unconditional.
* scalb should not be declared for __USE_XOPEN2K8, and scalbf and
scalbl are non-POSIX (as in bug 18967).
This patch fixes all these issues (it doesn't seem worth splitting
them into separate patches or bugs). I put __USE_ISOC99 conditionals,
where needed, around both float and long double declarations, even
though formally redundant around the long double declarations because
__MATH_DECLARE_LDOUBLE isn't defined without __USE_ISOC99; it seemed
clearer that way. The missing declarations of lgamma_r functions are
dealt with by directly using declarations of __lgamma*_r_finite, in
the implementation namespace, rather than having the inlines rely on
asm redirection of lgamma*_r.
After this patch, there are some apparently redundant nested
__USE_ISOC99 conditionals in lgamma / gamma definitions. These
actually reflect a separate bug (the correct condition for the lgamma
inline functions to set signgam is __USE_MISC || __USE_XOPEN, the
condition under which signgam is declared, rather than disabling
setting it if __USE_ISOC99, which includes XSI POSIX versions for
which signgam *should* be set). They'll be fixed as part of a fix for
that bug, which will also add tests for these inlines. I've put a
note about more general conform/ test coverage for -ffinite-math-only
on
<https://sourceware.org/glibc/wiki/Development_Todo/Master#conformtest_improvements>,
alongside other options for which this is also relevant (some of which
have also had such bugs in the past relating to mismatched
conditionals).
I also intend to enable the main libm-test.inc tests for the
math-finite.h functions, but some other bugs in __*_finite need fixing
first.
[BZ #19205]
* math/bits/math-finite.h (acosf): Condition declaration on
[__USE_ISOC99].
(acosl): Likewise.
(acoshf): Likewise.
(acoshl): Likewise.
(asinf): Likewise.
(asinl): Likewise.
(atan2f): Likewise.
(atan2l): Likewise.
(atanhf): Likewise.
(atanhl): Likewise.
(coshf): Likewise.
(coshl): Likewise.
(expf): Likewise.
(expl): Likewise.
(fmodf): Likewise.
(fmodl): Likewise.
(hypot): Change condition to [__USE_XOPEN || __USE_ISOC99].
(j0f): Change condition to [__USE_MISC && __USE_ISOC99].
(j0l): Likewise.
(y0f): Likewise.
(y0l): Likewise.
(j1f): Likewise.
(j1l): Likewise.
(y1f): Likewise.
(y1l): Likewise.
(jnf): Likewise.
(jnl): Likewise.
(ynf): Likewise.
(ynl): Likewise.
(lgammaf_r): Condition declaration on [__USE_ISOC99].
(lgammal_r): Likewise.
(__lgamma_r_finite): New declaration.
(__lgammaf_r_finite): Likewise.
(__lgammal_r_finite): Likewise.
(lgamma): Use __lgamma_r_finite.
(lgammaf): Condition definition on [__USE_ISOC99]. Use
__lgammaf_r_finite.
(lgammal): Condition definition on [__USE_ISOC99]. Use
__lgammal_r_finite.
(gamma): Do not define for [!__USE_MISC && __USE_XOPEN2K]. Use
__lgamma_r_finite.
(gammaf): Condition definition on [__USE_ISOC99]. Use
__lgammaf_r_finite.
(gammal): Condition definition on [__USE_ISOC99]. Use
__lgammal_r_finite.
(logf): Condition declaration on [__USE_ISOC99].
(logl): Likewise.
(log10f): Likewise.
(log10l): Likewise.
(ldexpf): Likewise.
(ldexpl): Likewise.
(powf): Likewise.
(powl): Likewise.
(remainder): Condition declaration on [__USE_XOPEN_EXTENDED ||
__USE_ISOC99].
(remainderf): Condition declaration on [__USE_ISOC99].
(remainderl): Likewise.
(scalb): Do not declare for [!__USE_MISC && __USE_XOPEN2K8].
(scalbf): Change condition to [__USE_MISC && __USE_ISOC99].
(scalbl): Likewise.
(sinhf): Condition declaration on [__USE_ISOC99].
(sinhl): Likewise.
(sqrtf): Likewise.
(sqrtl): Likewise.
The check for only __GNUC_STDC_INLINE__ and __GNUC_GNU_INLINE__ may
not be sufficient since those flags were added during initial support
for C99 inlining semantics. There is also a problem with always
defining __extern_inline and __extern_always_inline, since it enables
inline wrapper functions even when GNU inlining semantics are not
guaranteed. This, along with the possibility of such wrappers using
redirection (btowc for example) could result in compiler generating an
infinitely recusrive call to the function.
In fact it was such a recursion that led to this code being written
the way it was; see:
https://bugzilla.redhat.com/show_bug.cgi?id=186410
The initial change was to fix bugs 14530 and 13741, but they can be
resolved by checking if __fortify_function and/or
__extern_always_inline are defined, as it has been done in this patch.
In addition, I have audited uses of __extern_always_inline to make
sure that none of the uses result in compilation errors.
There is however a regression in this patch for llvm, since it reverts
the llvm expectation that __GNUC_STDC_INLINE__ or __GNUC_GNU_INLINE__
definition imply proper extern inline semantics.
2014-09-16 Siddhesh Poyarekar <siddhesh@redhat.com>
Jakub Jelinek <jakub@redhat.com>
[BZ #17266]
* libio/stdio.h: Check definition of __fortify_function
instead of __extern_always_inline to include bits/stdio2.h.
* math/bits/math-finite.h [__USE_XOPEN || __USE_ISOC99]: Also
check if __extern_always_inline is defined.
[__USE_MISC || __USE_XOPEN]: Likewise.
[__USE_ISOC99] Likewise.
* misc/sys/cdefs.h (__fortify_function): Define only if
__extern_always_inline is defined.
[!__cplusplus || __GNUC_PREREQ (4,3)]: Revert to defining
__extern_always_inline and __extern_inline only for g++-4.3
and newer or a compatible gcc.
