[Bug fortran/52038] New: [4.7 regression] fortran bootstrap failure: no previous prototype for 'symbol_as'

["mikpe at it dot uu.se" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=52038

             Bug #: 52038
           Summary: [4.7 regression] fortran bootstrap failure: no
                    previous prototype for 'symbol_as'
    Classification: Unclassified
           Product: gcc
           Version: 4.7.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: mikpe@it.uu.se


Bootstrapping gcc-4.7-20120128 on i686-linux with fortran enabled and
--disable-build-poststage1-with-cxx fails in stage 2 due to:

/mnt/scratch/objdir47/./prev-gcc/xgcc -B/mnt/scratch/objdir47/./prev-gcc/
-B/mnt/scratch/install47/i686-pc-linux-gnu/bin/
-B/mnt/scratch/install47/i686-pc-linux-gnu/bin/
-B/mnt/scratch/install47/i686-pc-linux-gnu/lib/ -isystem
/mnt/scratch/install47/i686-pc-linux-gnu/include -isystem
/mnt/scratch/install47/i686-pc-linux-gnu/sys-include    -c  -DIN_GCC_FRONTEND
-g -O2 -gtoggle -DIN_GCC   -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual
-Wstrict-prototypes -Wmissing-prototypes -Wmissing-format-attribute -pedantic
-Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror
-Wold-style-definition -Wc++-compat   -DHAVE_CONFIG_H -I. -Ifortran
-I/mnt/scratch/gcc-4.7-20120128/gcc -I/mnt/scratch/gcc-4.7-20120128/gcc/fortran
-I/mnt/scratch/gcc-4.7-20120128/gcc/../include
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libcpp/include
-I/home/mikpe/pkgs/linux-x86/gmp-5.0.3/include
-I/home/mikpe/pkgs/linux-x86/mpfr-3.1.0/include
-I/home/mikpe/pkgs/linux-x86/mpc-0.9/include 
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libdecnumber
-I/mnt/scratch/gcc-4.7-20120128/gcc/../libdecnumber/bid -I../libdecnumber   
/mnt/scratch/gcc-4.7-20120128/gcc/fortran/resolve.c -o fortran/resolve.o
/mnt/scratch/gcc-4.7-20120128/gcc/fortran/resolve.c:1586:1: error: no previous
prototype for 'symbol_as' [-Werror=missing-prototypes]
cc1: all warnings being treated as errors

make[3]: *** [fortran/resolve.o] Error 1

The previous weekly snapshot, 4.7-20120121, bootstrapped fine.

Looking at the diff the reason is obvious: a non-static definition of
symbol_as() was added to resolve.c, but there's (a) no prototype for it, and
(b) no uses either.

Disabling symbol_as() with #if 0 / #endif allowed the bootstrap to complete.