multiple definition of `RAM'

[DNSGeek]

Trying to build on a stock Fedora 32 system (x86_64) gives me the following error:

[tdknox@fedoravm cbmbasic]$ make
cc -Wall -O3   -c -o cbmbasic.o cbmbasic.c
cbmbasic.c: In function ‘main’:
cbmbasic.c:1201:17: warning: variable ‘llvm_cbe_tmp1038410385_2e_lobit’ set but not used [-Wunused-but-set-variable]
 1201 |   unsigned char llvm_cbe_tmp1038410385_2e_lobit;
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cbmbasic.c:1200:17: warning: variable ‘llvm_cbe_tmp1038210383’ set but not used [-Wunused-but-set-variable]
 1200 |   unsigned char llvm_cbe_tmp1038210383;
      |                 ^~~~~~~~~~~~~~~~~~~~~~
cbmbasic.c:195:18: warning: variable ‘llvm_cbe_tmp1845’ set but not used [-Wunused-but-set-variable]
  195 |   unsigned char *llvm_cbe_tmp1845;
      |                  ^~~~~~~~~~~~~~~~
cbmbasic.c:194:18: warning: variable ‘ltmp_2_1’ set but not used [-Wunused-but-set-variable]
  194 |   unsigned char *ltmp_2_1;
      |                  ^~~~~~~~
cbmbasic.c:193:18: warning: variable ‘ltmp_1_1’ set but not used [-Wunused-but-set-variable]
  193 |   unsigned char *ltmp_1_1;
      |                  ^~~~~~~~
cbmbasic.c:192:18: warning: variable ‘ltmp_0_1’ set but not used [-Wunused-but-set-variable]
  192 |   unsigned char *ltmp_0_1;
      |                  ^~~~~~~~
cc -Wall -O3   -c -o runtime.o runtime.c
runtime.c: In function ‘OPEN’:
runtime.c:290:45: warning: pointer targets in passing argument 1 of ‘fopen’ differ in signedness [-Wpointer-sign]
  290 |         kernal_files[kernal_lfn] = fopen(RAM+kernal_filename, mode);
      |                                          ~~~^~~~~~~~~~~~~~~~
      |                                             |
      |                                             unsigned char *
In file included from runtime.c:30:
/usr/include/stdio.h:246:44: note: expected ‘const char * restrict’ but argument is of type ‘unsigned char *’
  246 | extern FILE *fopen (const char *__restrict __filename,
      |                     ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~
runtime.c: In function ‘LOAD’:
runtime.c:552:17: warning: variable ‘savedbyte’ set but not used [-Wunused-but-set-variable]
  552 |   unsigned char savedbyte;
      |                 ^~~~~~~~~
runtime.c: In function ‘SAVE’:
runtime.c:695:17: warning: variable ‘savedbyte’ set but not used [-Wunused-but-set-variable]
  695 |   unsigned char savedbyte;
      |                 ^~~~~~~~~
cc -Wall -O3   -c -o plugin.o plugin.c
plugin.c: In function ‘plugin_gone’:
plugin.c:242:18: warning: variable ‘b’ set but not used [-Wunused-but-set-variable]
  242 |    unsigned char b;
      |                  ^
cc -Wall -O3   -c -o console.o console.c
cc -o cbmbasic cbmbasic.o runtime.o plugin.o console.o
/usr/bin/ld: runtime.o:(.bss+0x120): multiple definition of `RAM'; cbmbasic.o:(.bss+0x20): first defined here
collect2: error: ld returned 1 exit status
make: *** [Makefile:10: cbmbasic] Error 1

[ifohancroft]

I am getting the exact same thing when trying to compile on Manjaro

[bwack]

I guess this is related to GCC 10. I'm on GCC 9 and don't get that error, however if I set -fno-common option I get the same error. You can read about this here:
https://gcc.gnu.org/gcc-10/porting_to.html (Default to -fno-common)

You can either try fixing the source code by setting RAM to extern in all but one c file, or you can try in the makefile to add -fcommon to CFLAGS

[bwack]

cbmbasic/runtime.c

Line 47 in 89093eb

unsigned char RAM[65536];

this should be extern i think. Yep, just tried this now and it works.