I am trying to compile and isntall the gcc 5.5.0 compiler in the opensuse 11.4 SLES . During compilation I got an error that mpfr_snprintf is undefined, in file that is located in x86_64-unknown-linux-gnu-gcc directory. Specifically the file is the usban.c. I have installed the approrpiate libary. Has anyone any point how to fix this?
Below you can found the full link command and the error
g++ -g -DIN_GCC -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wwrite-strings -Wcast-qual -Wno-format -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -fno-common -DHAVE_CONFIG_H -o cc1 c/c-lang.o c-family/stub-objc.o attribs.o c/c-errors.o c/c-decl.o c/c-typeck.o c/c-convert.o c/c-aux-info.o c/c-objc-common.o c/c-parser.o c/c-array-notation.o c-family/c-common.o c-family/c-cppbuiltin.o c-family/c-dump.o c-family/c-format.o c-family/c-gimplify.o c-family/c-lex.o c-family/c-omp.o c-family/c-opts.o c-family/c-pch.o c-family/c-ppoutput.o c-family/c-pragma.o c-family/c-pretty-print.o c-family/c-semantics.o c-family/c-ada-spec.o c-family/c-cilkplus.o c-family/array-notation-common.o c-family/cilk.o c-family/c-ubsan.o i386-c.o glibc-c.o \
cc1-checksum.o libbackend.a main.o tree-browser.o libcommon-target.a libcommon.a ../libcpp/libcpp.a ../libdecnumber/libdecnumber.a libcommon.a ../libcpp/libcpp.a ../libbacktrace/.libs/libbacktrace.a ../libiberty/libiberty.a ../libdecnumber/libdecnumber.a -lmpc -lmpfr -lgmp -rdynamic -ldl -L../zlib -lz
libbackend.a(ubsan.o): In function `ubsan_instrument_float_cast(unsigned int, tree_node*, tree_node*, tree_node*)':
/root/Desktop/gcc-5.5.0/host-x86_64-unknown-linux-gnu/gcc/../.././gcc/ubsan.c:1584: undefined reference to `mpfr_snprintf'
/root/Desktop/gcc-5.5.0/host-x86_64-unknown-linux-gnu/gcc/../.././gcc/ubsan.c:1598: undefined reference to `mpfr_snprintf'
collect2: ld returned 1 exit status
make[3]: *** [cc1] Error 1
make[3]: Leaving directory `/root/Desktop/gcc-5.5.0/host-x86_64-unknown-linux-gnu/gcc'
make[2]: *** [all-stage1-gcc] Error 2
make[2]: Leaving directory `/root/Desktop/gcc-5.5.0'
make[1]: *** [stage1-bubble] Error 2
make[1]: Leaving directory `/root/Desktop/gcc-5.5.0'
make: *** [all] Error 2

You really should try google for this sort of thing. I just pasted mpfr_snprintf intop a search window and the second hit I got was http://www.mpfr.org/mpfr-2.4.1/ which seems to be what you're looking for.

You don't want a .c file - that's code. You want a library(.so), or possibly a header (.h)

Mandatory Warnings:
1. SuSE of any shade uses rpms, and automagic dependencies. When you start compiling on any rpm distro, IME you get about 2 years before you hit massive compatibility problems and a reinstall becomes wise.

2. Looks like you'll have to compile that. Once you've installed that with 'make install', I'm sure you'll put in stuff doesn't know is there. It's worth getting the SuSE rpm if such exists. Failing that, it's worth learning how to build rpms.