undefined reference to "only some math.h" functions

theAlse picture theAlse · Jun 30, 2011 · Viewed 37.8k times · Source

I am having a strange problem.

The math libraries has been added to my makefile.

# include standard C library
LDFLAGS += -lc
# include standard math library
LDFLAGS += -lm

and in the output file (.map) I can see that everything has been linked properly:

LOAD c:/gnu/powerpc-eabi/3pp.ronetix.powerpc-eabi/bin/../lib/gcc/powerpc-eabi/4.3.3/nof\libgcc.a
LOAD c:/gnu/powerpc-eabi/3pp.ronetix.powerpc-eabi/bin/../lib/gcc/powerpc-eabi/4.3.3/../../../../powerpc-eabi/lib/nof\libc.a
LOAD c:/gnu/powerpc-eabi/3pp.ronetix.powerpc-eabi/bin/../lib/gcc/powerpc-eabi/4.3.3/../../../../powerpc-eabi/lib/nof\libm.a

when I do

z = pow((double) 2, (double) 3);

it works fine. But if I test another function like:

double result = asin(x);

I´ll get:

undefined reference to `asin'
collect2: ld returned 1 exit status

How can this be? both pow and asin are available in math.h, see below:

/* Non reentrant ANSI C functions.  */

#ifndef _REENT_ONLY
#ifndef __math_6881
extern double acos _PARAMS((double));
extern double asin _PARAMS((double));
extern double atan2 _PARAMS((double, double));
extern double cosh _PARAMS((double));
extern double sinh _PARAMS((double));
extern double exp _PARAMS((double));
extern double ldexp _PARAMS((double, int));
extern double log _PARAMS((double));
extern double log10 _PARAMS((double));
extern double pow _PARAMS((double, double));
extern double sqrt _PARAMS((double));
extern double fmod _PARAMS((double, double));
#endif /* ! defined (__math_68881) */
#endif /* ! defined (_REENT_ONLY) */

how can one work and the other one generate linker issue? If I run -nm on libm.a I´ll get the following result: (sorry for the huge output, I have only copied the sections with the word sin)

lib_a-e_asin.o:
         U __adddf3
         U __divdf3
         U __gtdf2
00000000 T __ieee754_asin
         U __ieee754_sqrt
         U __muldf3
         U __subdf3
         U fabs

lib_a-e_j0.o:
         U __adddf3
         U __divdf3
         U __gtdf2
00000470 T __ieee754_j0
         U __ieee754_log
         U __ieee754_sqrt
000009b8 T __ieee754_y0
         U __ltdf2
         U __muldf3
         U __subdf3
         U cos
         U fabs
000000b0 r pR2
00000108 r pR3
00000058 r pR5
00000000 r pR8
000000e0 r pS2
00000138 r pS3
00000088 r pS5
00000030 r pS8
00000004 t pzero
00000220 r qR2
00000280 r qR3
000001c0 r qR5
00000160 r qR8
00000250 r qS2
000002b0 r qS3
000001f0 r qS5
00000190 r qS8
00000218 t qzero
         U sin

lib_a-e_j1.o:
         U __adddf3
         U __divdf3
         U __gtdf2
00000470 T __ieee754_j1
         U __ieee754_log
         U __ieee754_sqrt
00000950 T __ieee754_y1
         U __muldf3
         U __subdf3
         U cos
         U fabs
00000004 t pone
000000b0 r pr2
00000108 r pr3
00000058 r pr5
00000000 r pr8
000000e0 r ps2
00000138 r ps3
00000088 r ps5
00000030 r ps8
00000218 t qone
00000220 r qr2
00000280 r qr3
000001c0 r qr5
00000160 r qr8
00000250 r qs2
000002b0 r qs3
000001f0 r qs5
00000190 r qs8
         U sin

lib_a-e_jn.o:
         U __adddf3
         U __divdf3
         U __floatsidf
         U __gedf2
         U __gtdf2
         U __ieee754_j0
         U __ieee754_j1
00000434 T __ieee754_jn
         U __ieee754_log
         U __ieee754_sqrt
         U __ieee754_y0
         U __ieee754_y1
00000000 T __ieee754_yn
         U __ltdf2
         U __muldf3
         U __subdf3
         U cos
         U fabs
         U sin


lib_a-e_sinh.o:
         U __adddf3
         U __divdf3
         U __gtdf2
         U __ieee754_exp
00000000 T __ieee754_sinh
         U __muldf3
         U __subdf3
         U expm1
         U fabs


lib_a-ef_asin.o:
         U __addsf3
         U __divsf3
         U __gtsf2
00000000 T __ieee754_asinf
         U __ieee754_sqrtf
         U __mulsf3
         U __subsf3
         U fabsf


lib_a-ef_j0.o:
         U __addsf3
         U __divsf3
         U __gtsf2
0000035c T __ieee754_j0f
         U __ieee754_logf
         U __ieee754_sqrtf
000006cc T __ieee754_y0f
         U __ltsf2
         U __mulsf3
         U __subsf3
         U cosf
         U fabsf
00000058 r pR2
00000084 r pR3
0000002c r pR5
00000000 r pR8
00000070 r pS2
0000009c r pS3
00000044 r pS5
00000018 r pS8
00000004 t pzerof
00000110 r qR2
00000140 r qR3
000000e0 r qR5
000000b0 r qR8
00000128 r qS2
00000158 r qS3
000000f8 r qS5
000000c8 r qS8
000001a0 t qzerof
         U sinf

lib_a-ef_j1.o:
         U __addsf3
         U __divsf3
         U __gtsf2
0000031c T __ieee754_j1f
         U __ieee754_logf
         U __ieee754_sqrtf
0000062c T __ieee754_y1f
         U __mulsf3
         U __subsf3
         U cosf
         U fabsf
00000004 t ponef
00000058 r pr2
00000084 r pr3
0000002c r pr5
00000000 r pr8
00000070 r ps2
0000009c r ps3
00000044 r ps5
00000018 r ps8
000001a0 t qonef
000000b0 r qr2
000000e0 r qr8
000000c8 r qs2
000000f8 r qs8
         U sinf

lib_a-ef_sinh.o:
         U __addsf3
         U __divsf3
         U __gtsf2
         U __ieee754_expf
00000000 T __ieee754_sinhf
         U __mulsf3
         U __subsf3
         U expm1f
         U fabsf

lib_a-er_lgamma.o:
         U __adddf3
         U __divdf3
         U __eqdf2
         U __fixdfsi
         U __floatsidf
00000004 T __ieee754_lgamma_r
         U __ieee754_log
         U __kernel_cos
         U __kernel_sin
         U __ltdf2
         U __muldf3
         U __nedf2
         U __subdf3
         U fabs
         U floor


lib_a-erf_lgamma.o:
         U __addsf3
         U __divsf3
         U __eqsf2
         U __fixsfsi
         U __floatsisf
00000004 T __ieee754_lgammaf_r
         U __ieee754_logf
         U __kernel_cosf
         U __kernel_sinf
         U __ltsf2
         U __mulsf3
         U __nesf2
         U __subsf3
         U fabsf
         U floorf

lib_a-k_sin.o:
         U __adddf3
         U __fixdfsi
00000000 T __kernel_sin
         U __muldf3
         U __subdf3

lib_a-kf_sin.o:
         U __addsf3
         U __fixsfsi
00000000 T __kernel_sinf
         U __mulsf3
         U __subsf3

lib_a-s_asinh.o:
         U __adddf3
         U __divdf3
         U __gtdf2
         U __ieee754_log
         U __ieee754_sqrt
         U __muldf3
00000000 T asinh
         U fabs
         U log1p

lib_a-s_cos.o:
         U __ieee754_rem_pio2
         U __kernel_cos
         U __kernel_sin
         U __subdf3
00000000 T cos

lib_a-s_isinf.o:
00000000 T isinf

lib_a-s_isinfd.o:
00000000 T __isinfd

lib_a-s_sin.o:
         U __ieee754_rem_pio2
         U __kernel_cos
         U __kernel_sin
         U __subdf3
00000000 T sin

lib_a-sf_asinh.o:
         U __addsf3
         U __divsf3
         U __gtsf2
         U __ieee754_logf
         U __ieee754_sqrtf
         U __mulsf3
00000000 T asinhf
         U fabsf
         U log1pf

lib_a-sf_cos.o:
         U __ieee754_rem_pio2f
         U __kernel_cosf
         U __kernel_sinf
         U __subsf3
00000000 T cosf

lib_a-sf_isinf.o:
00000000 T isinff

lib_a-sf_isinff.o:
00000000 T __isinff

lib_a-sf_sin.o:
         U __ieee754_rem_pio2f
         U __kernel_cosf
         U __kernel_sinf
         U __subsf3
00000000 T sinf

lib_a-w_asin.o:
         U __errno
         U __fdlib_version
         U __gtdf2
         U __ieee754_asin
         U __isnand
00000004 T asin
         U fabs
         U matherr
         U nan

lib_a-w_sincos.o:
         U cos
         U sin
00000000 T sincos

lib_a-w_sinh.o:
         U __errno
         U __fdlib_version
         U __gtdf2
         U __ieee754_sinh
         U finite
         U matherr
00000004 T sinh

lib_a-wf_asin.o:
         U __errno
         U __extendsfdf2
         U __fdlib_version
         U __gtsf2
         U __ieee754_asinf
         U __truncdfsf2
00000004 T asinf
         U fabsf
         U isnanf
         U matherr
         U nan

lib_a-wf_sincos.o:
         U cosf
00000000 T sincosf
         U sinf

lib_a-wf_sinh.o:
         U __errno
         U __extendsfdf2
         U __fdlib_version
         U __gtsf2
         U __ieee754_sinhf
         U __truncdfsf2
         U finitef
         U matherr
00000004 T sinhf

EDIT1: I tested some more and the problem is as follows (not what I originally stated above):

double aa;
double bb = 1.0;
double cc;
aa = sin(1.0);
cc = sin (bb);

What happens when I try to build is that I get a 'undefined reference' at the last line, meaning that when I use constants it is fine, but when I pass variables to the sin functions it will not link. I also tested many of the other math function and I´ll get the exact same linker issue. As soon as I pass a variable to a math function I can not link any more. any ideas?

Answer

ottelo picture ottelo · Sep 27, 2012

The sequence for -lm -lc -lgcc plays a very important role. Only this sequence works for me.

These commands go to the Linker Options!