qsort_r missing on some platforms

[Zach Welch <zwelch at codesourcery dot com>]

Howdy,

I just tried to build the current elfutils Git repository and get the
following errors. The missing qsort_r resulted from having an old
version of the GNU C library (libc-2.7.so). I imagine the sign
comparison may be related.

gcc -D_GNU_SOURCE -DHAVE_CONFIG_H
-DLOCALEDIR='"/scratch/zwelch/elfutils-install/share/locale"'
-DDEBUGPRED=0 -DSRCDIR=\"/scratch/zwelch/elfutils/src\"
-DOBJDIR=\"/scratch/zwelch/elfutils/src\" -I. -I.. -I. -I. -I../lib -I..
-I./../libelf -I./../libebl -I./../libdw -I./../libdwfl -I./../libasm
-std=gnu99 -Wall -Wshadow -Werror -Wunused -Wextra -Wformat=2   -g -O2
-MT readelf.o -MD -MP -MF .deps/readelf.Tpo -c -o readelf.o readelf.c
cc1: warnings being treated as errors
readelf.c: In function 'sort_listptr':
readelf.c:4360: error: implicit declaration of function 'qsort_r'
readelf.c: In function 'print_debug_ranges_section':
readelf.c:4566: error: comparison between signed and unsigned
readelf.c: In function 'print_debug_loc_section':
readelf.c:6337: error: comparison between signed and unsigned
make[2]: *** [readelf.o] Error 1

For now, I simply went back to elfutils-0.146 tag (which builds fine on
the same host and allows me to continue with my intended tasks). I would
be happy to help produce or verify a fix that allows me to work with the
master branch, but a workaround for the missing qsort_r function was not
immediately obvious to me.

-- 
Zach Welch
CodeSourcery
zwelch@codesourcery.com
(650) 331-3385 x743