g++ and g77 linking problem, gcc-2.95.3

[Dan, Ho-Jin]

fortran file was compiled with g77 and c file with g++ instead of gcc.
gcc & g77 combination was good with linking flags  -lg2c -lm but
g++ didn't work. my test program was build as below,

---makefile
fcallc.o : fcallc.c
   g77 -c $<
subr.o : subr.c
   gcc -c $<                                       
fcallc : fcallc.o subr.o
   gcc -o $@ fcallc.o subr.o -lg2c -lm 
#also tested g++ -o $@ subr.o fcallc.o -lg2c -lm

I could't change gcc to g++ because ld complained as
fcallc.o(...) : undefined reference to 'subrt_'
any idea? thanks in advance...