[Bug bootstrap/50758] New: [4.7 Regression] Bootstrap fails at stage 2 on x86_64-apple-darwin10: error: variable 'token_no' set but not used

["dominiq at lps dot ens.fr" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=50758

             Bug #: 50758
           Summary: [4.7 Regression] Bootstrap fails at stage 2 on
                    x86_64-apple-darwin10: error: variable 'token_no' set
                    but not used
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: dominiq@lps.ens.fr
                CC: dodji@gcc.gnu.org


At revision 180087 bootstrap fails at stage 2 on x86_64-apple-darwin10:

/opt/gcc/build_w/./prev-gcc/g++ -B/opt/gcc/build_w/./prev-gcc/
-B/opt/gcc/gcc4.7w/x86_64-apple-darwin10.8.0/bin/ -nostdinc++
-B/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/src/.libs
-B/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/libsupc++/.libs
-I/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/include/x86_64-apple-darwin10.8.0
-I/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/include
-I/opt/gcc/work/libstdc++-v3/libsupc++
-L/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/src/.libs
-L/opt/gcc/build_w/prev-x86_64-apple-darwin10.8.0/libstdc++-v3/libsupc++/.libs 
-I../../work/libcpp -I. -I../../work/libcpp/../include
-I../../work/libcpp/include -I/opt/sw64/include -g -O2 -mdynamic-no-pic
-gtoggle -W -Wall -Wwrite-strings -Wmissing-format-attribute -pedantic
-Wno-long-long -Werror -I../../work/libcpp -I. -I../../work/libcpp/../include
-I../../work/libcpp/include -I/opt/sw64/include -c -o line-map.o -MT line-map.o
-MMD -MP -MF .deps/line-map.Tpo ../../work/libcpp/line-map.c
../../work/libcpp/line-map.c: In function 'source_location
linemap_macro_map_loc_to_exp_point(const line_map*, source_location)':
../../work/libcpp/line-map.c:628:12: error: variable 'token_no' set but not
used [-Werror=unused-but-set-variable]
cc1plus: all warnings being treated as errors

This code was introduced at revision 180081.
AFAIU the code, the warning seems bogus.