Re: FAIL: test-strtod

[Eric Blake]

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[re-adding the list, and also adding bug-gnulib, since this particular
problem is related to gnulib.  For bug-gnulib readers: this is a report of
test-strtod failure on Solaris 10]

According to Dennis Clarke on 7/29/2008 10:09 PM:
| whoops
|
| builds fine .. and then make check gets ugly :
|
| source='test-strtod.c' object='test-strtod.o' libtool=no \
|         DEPDIR=.deps depmode=none /bin/bash ../build-aux/depcomp \
|         c99  -I. -I../lib  -I. -I. -I.. -I./.. -I../lib -I./../lib
| -I/opt/build/dclarke/local/include -D_REENTRANT  -erroff=%all
| -fsimple=0 -g -m64 -xO1 -Qy -Xa -xbuiltin=%none -xdebugformat=dwarf
| -xmodel=medium -xnolibmil -xnolibmopt -xregs=no%frameptr -xs
| -xstrconst -xtarget=opteron -xtemp=/tmp/dclarke -c test-strtod.c
| c99  -erroff=%all -fsimple=0 -g -m64 -xO1 -Qy -Xa -xbuiltin=%none
| -xdebugformat=dwarf -xmodel=medium -xnolibmil -xnolibmopt
| -xregs=no%frameptr -xs -xstrconst -xtarget=opteron -xtemp=/tmp/dclarke
|   -o test-strtod test-strtod.o libtests.a ../lib/libm4.a libtests.a
| Undefined                       first referenced
|  symbol                             in file
| fabs                                test-strtod.o

Ah.  So it looks like when you turn on all the C99 flags to your compiler,
that strtod(3) no longer fails the configure test.  But then test-strtod
fails to link, because it is lacking -lm on the command line.  You're the
first person to report this particular failure of a missing library in the
test link line; most platforms (including Solaris 10 without the proper
C99 compliance flags) have already failed the configure test, such that
POW_LIB is defined as -lm when needed, or provide fabs as part of libc
instead of libm.

Somehow, the test needs to be made more robust; we either need more m4
magic to determine if -lm is necessary for fabs, or a gnulib replacement
for fabs that works without requiring libm, or a way to rewrite that test
to not need fabs.  In the meantime, feel free to manually add -lm to the
link line for that particular test program.

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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