Fix build with GCC 10 when long double = double.

On platforms where long double has the same ABI as double, glibc
defines long double functions as aliases for the corresponding double
functions.  The declarations of those functions in <math.h> are
disabled to avoid problems with aliases having incompatible types, but
GCC 10 now gives errors for incompatible types when the long double
function is known to GCC as a built-in function, not just when there
is an incompatible header declaration.

This patch fixes those errors by using appropriate
-fno-builtin-<function> options to compile the double functions.  The
list of CFLAGS-* settings is an appropriately adapted version of that
in sysdeps/ieee754/ldbl-opt/Makefile used there for building nldbl-*.c
files; in particular, the options are used even if GCC does not
currently have a built-in function of a given function, so that adding
such a built-in function in future will not break the glibc build.
Thus, various of the CFLAGS-* settings are only for future-proofing
and may not currently be needed (and it's possible some could be
irrelevant for other reasons).

Tested with build-many-glibcs.py for arm-linux-gnueabi (compilers and
glibcs builds), where it fixes the build that previously failed.
This commit is contained in:
Joseph Myers 2020-03-17 22:57:42 +00:00
parent cbd1569904
commit 49348beafe

View File

@ -650,6 +650,128 @@ ifneq ($(long-double-fcts),yes)
# We won't compile the `long double' code at all. Tell the `double' code
# to define aliases for the `FUNCl' names.
math-CPPFLAGS += -DNO_LONG_DOUBLE
# GCC 10 diagnoses aliases with types conflicting with built-in
# functions.
CFLAGS-w_acos.c += -fno-builtin-acosl
CFLAGS-w_acosh.c += -fno-builtin-acoshl
CFLAGS-w_asin.c += -fno-builtin-asinl
CFLAGS-s_asinh.c += -fno-builtin-asinhl
CFLAGS-s_atan.c += -fno-builtin-atanl
CFLAGS-w_atan2.c += -fno-builtin-atan2l
CFLAGS-w_atanh.c += -fno-builtin-atanhl
CFLAGS-s_cabs.c += -fno-builtin-cabsl
CFLAGS-s_cacos.c += -fno-builtin-cacosl
CFLAGS-s_cacosh.c += -fno-builtin-cacoshl
CFLAGS-s_canonicalize.c += -fno-builtin-canonicalizel
CFLAGS-s_carg.c += -fno-builtin-cargl
CFLAGS-s_casin.c += -fno-builtin-casinl
CFLAGS-s_casinh.c += -fno-builtin-casinhl
CFLAGS-s_catan.c += -fno-builtin-catanl
CFLAGS-s_catanh.c += -fno-builtin-catanhl
CFLAGS-s_cbrt.c += -fno-builtin-cbrtl
CFLAGS-s_ccos.c += -fno-builtin-ccosl
CFLAGS-s_ccosh.c += -fno-builtin-ccoshl
CFLAGS-s_ceil.c += -fno-builtin-ceill
CFLAGS-s_cexp.c += -fno-builtin-cexpl
CFLAGS-s_cimag.c += -fno-builtin-cimagl
CFLAGS-s_clog.c += -fno-builtin-clogl
CFLAGS-s_clog10.c += -fno-builtin-clog10l
CFLAGS-s_conj.c += -fno-builtin-conjl
CFLAGS-s_copysign.c += -fno-builtin-copysignl
CFLAGS-s_cos.c += -fno-builtin-cosl
CFLAGS-w_cosh.c += -fno-builtin-coshl
CFLAGS-s_cpow.c += -fno-builtin-cpowl
CFLAGS-s_cproj.c += -fno-builtin-cprojl
CFLAGS-s_creal.c += -fno-builtin-creall
CFLAGS-s_csin.c += -fno-builtin-csinl
CFLAGS-s_csinh.c += -fno-builtin-csinhl
CFLAGS-s_csqrt.c += -fno-builtin-csqrtl
CFLAGS-s_ctan.c += -fno-builtin-ctanl
CFLAGS-s_ctanh.c += -fno-builtin-ctanhl
CFLAGS-s_dadd.c += -fno-builtin-daddl
CFLAGS-s_ddiv.c += -fno-builtin-ddivl
CFLAGS-s_dmul.c += -fno-builtin-dmull
CFLAGS-s_dsub.c += -fno-builtin-dsubl
CFLAGS-s_erf.c += -fno-builtin-erfl
CFLAGS-s_erfc.c += -fno-builtin-erfcl
CFLAGS-e_exp.c += -fno-builtin-expl
CFLAGS-w_exp10.c += -fno-builtin-exp10l
CFLAGS-e_exp2.c += -fno-builtin-exp2l
CFLAGS-s_expm1.c += -fno-builtin-expm1l
CFLAGS-s_fabs.c += -fno-builtin-fabsl
CFLAGS-s_fadd.c += -fno-builtin-faddl
CFLAGS-s_fdim.c += -fno-builtin-fdiml
CFLAGS-s_fdiv.c += -fno-builtin-fdivl
CFLAGS-s_finite.c += -fno-builtin-finitel
CFLAGS-s_floor.c += -fno-builtin-floorl
CFLAGS-s_fma.c += -fno-builtin-fmal
CFLAGS-s_fmax.c += -fno-builtin-fmaxl
CFLAGS-s_fmaxmag.c += -fno-builtin-fmaxmagl
CFLAGS-s_fmin.c += -fno-builtin-fminl
CFLAGS-s_fminmag.c += -fno-builtin-fminmagl
CFLAGS-w_fmod.c += -fno-builtin-fmodl
CFLAGS-s_fmul.c += -fno-builtin-fmull
CFLAGS-s_frexp.c += -fno-builtin-frexpl
CFLAGS-s_fromfp.c += -fno-builtin-fromfpl
CFLAGS-s_fromfpx.c += -fno-builtin-fromfpxl
CFLAGS-s_fsub.c += -fno-builtin-fsubl
CFLAGS-s_gamma.c += -fno-builtin-gammal
CFLAGS-s_getpayload.c += -fno-builtin-getpayloadl
CFLAGS-w_hypot.c += -fno-builtin-hypotl
CFLAGS-w_ilogb.c += -fno-builtin-ilogbl
CFLAGS-s_isinf.c += -fno-builtin-isinfl
CFLAGS-s_isnan.c += -fno-builtin-isnanl
CFLAGS-w_j0.c += -fno-builtin-j0l
CFLAGS-w_j1.c += -fno-builtin-j1l
CFLAGS-w_jn.c += -fno-builtin-jnl
CFLAGS-s_ldexp.c += -fno-builtin-ldexpl
CFLAGS-w_lgamma.c += -fno-builtin-lgammal
CFLAGS-w_lgamma_r.c += -fno-builtin-lgammal_r
CFLAGS-w_llogb.c += -fno-builtin-llogbl
CFLAGS-s_llrint.c += -fno-builtin-llrintl
CFLAGS-s_llround.c += -fno-builtin-llroundl
CFLAGS-e_log.c += -fno-builtin-logl
CFLAGS-w_log10.c += -fno-builtin-log10l
CFLAGS-w_log1p.c += -fno-builtin-log1pl
CFLAGS-e_log2.c += -fno-builtin-log2l
CFLAGS-s_logb.c += -fno-builtin-logbl
CFLAGS-s_lrint.c += -fno-builtin-lrintl
CFLAGS-s_lround.c += -fno-builtin-lroundl
CFLAGS-s_modf.c += -fno-builtin-modfl
CFLAGS-s_nan.c += -fno-builtin-nanl
CFLAGS-s_nearbyint.c += -fno-builtin-nearbyintl
CFLAGS-s_nextafter.c += -fno-builtin-nextafterl
CFLAGS-s_nextdown.c += -fno-builtin-nextdownl
CFLAGS-s_nexttoward.c += -fno-builtin-nexttoward -fno-builtin-nexttowardl
CFLAGS-s_nexttowardf.c += -fno-builtin-nexttowardf
CFLAGS-s_nextup.c += -fno-builtin-nextupl
CFLAGS-e_pow.c += -fno-builtin-powl
CFLAGS-w_remainder.c += -fno-builtin-remainderl -fno-builtin-dreml
CFLAGS-s_remquo.c += -fno-builtin-remquol
CFLAGS-s_rint.c += -fno-builtin-rintl
CFLAGS-s_round.c += -fno-builtin-roundl
CFLAGS-s_roundeven.c += -fno-builtin-roundevenl
CFLAGS-w_scalb.c += -fno-builtin-scalbl
CFLAGS-w_scalbln.c += -fno-builtin-scalblnl
CFLAGS-s_scalbn.c += -fno-builtin-scalbnl
CFLAGS-s_setpayload.c += -fno-builtin-setpayloadl
CFLAGS-s_setpayloadsig.c += -fno-builtin-setpayloadsigl
CFLAGS-s_significand.c += -fno-builtin-significandl
CFLAGS-s_sin.c += -fno-builtin-sinl
CFLAGS-s_sincos.c += -fno-builtin-sincosl
CFLAGS-w_sinh.c += -fno-builtin-sinhl
CFLAGS-w_sqrt.c += -fno-builtin-sqrtl
CFLAGS-s_tan.c += -fno-builtin-tanl
CFLAGS-s_tanh.c += -fno-builtin-tanhl
CFLAGS-w_tgamma.c += -fno-builtin-tgammal
CFLAGS-s_totalorder.c += -fno-builtin-totalorderl
CFLAGS-s_totalordermag.c += -fno-builtin-totalordermagl
CFLAGS-s_trunc.c += -fno-builtin-truncl
CFLAGS-s_ufromfp.c += -fno-builtin-ufromfpl
CFLAGS-s_ufromfpx.c += -fno-builtin-ufromfpxl
CFLAGS-s_y0.c += -fno-builtin-y0l
CFLAGS-s_y1.c += -fno-builtin-y1l
CFLAGS-s_yn.c += -fno-builtin-ynl
endif
# These files quiet sNaNs in a way that is optimized away without