🚀 go-pugleaf

Variables of type "void" generate "undefined symbols" 
in GCC 2.7.2.1 on SPARC/Solaris.   Is this a bug or a feature?

See example below.


First, with GCC 2.6.3 ==> No problem:
-----8<-------start---------------------------------------------------------
freke% cat void.c

void c_void;

main()
{
  printf("OK\n");
  exit(0);
}

freke% gcc-2.6.3 -c void.c
freke% nm void.o | grep c_void
void.o:
[4]     |         1|       0|OBJT |GLOB |0    |COMMON |c_void
freke% /usr/ccs/bin/ld void.o -lc
freke% a.out
OK
freke% 
-----8<-------end-----------------------------------------------------------
 

Then, with GCC 2.7.2.1 ==> linking problem:
-----8<-------start---------------------------------------------------------
freke% gcc -V 2.7.2.1 -c void.c
freke% nm void.o | grep c_void
void.o:
[10]    |         0|       0|NOTY |GLOB |0    |UNDEF  |c_void
freke% /usr/ccs/bin/ld void.o -lc
Undefined                       first referenced
 symbol                             in file
c_void                              void.o
ld: fatal: Symbol referencing errors. No output written to a.out
freke% 
-----8<-------end-----------------------------------------------------------


I already have two workarounds for this problem.

1) Use the GNU linker which comes with Binutils:
-----8<-------start---------------------------------------------------------
freke% gcc -V 2.7.2.1 -c void.c
freke% nm void.o | grep c_void
void.o:
[10]    |         0|       0|NOTY |GLOB |0    |UNDEF  |c_void
freke% /usr/local/sparc-sun-solaris2.5.1/bin/gld void.o -e main -lc
freke% a.out
OK
freke% 
-----8<-------end-----------------------------------------------------------

2) Use the -znodefs option to ld to suppress the error condition
(is this default for gld?):
-----8<-------start---------------------------------------------------------
freke% gcc -V 2.7.2.1 -c void.c
freke% nm void.o | grep c_void
void.o:
[12]    |         0|       0|NOTY |GLOB |0    |UNDEF  |c_void
freke% /usr/ccs/bin/ld -znodefs void.o -lc
freke% a.out
OK
freke%
-----8<-------end-----------------------------------------------------------

-- 
Ulf Lunde  <ulflunde@pvv.org>  http://www.pvv.org/~ulflunde/