🚀 go-pugleaf

   The following program has a SEGV when compiled with -O option on SUN4C
  ( SunOs 4.1.1 ).
   
   The involved part of the code is :

    fwd_symb *b = bindings;  // bindings is a member of a class and is set to 0

    // When -O is on, a SEGV occurs here.

    while( b && b->fun == 0 )
	b = b->next;

   The whole ( but small program ) is below.

   Thank you.

   P. Turlais

  The compile command is :

gcc -v -O tt.cc
Reading specs from /d/turlais/lib/gcc-lib/sun4/2.2.2/specs
gcc version 2.2.2
 /d/turlais/lib/gcc-lib/sun4/2.2.2/cpp -lang-c++ -v -undef -D__GNUC__=2 -D__GNUG__=2 -D__cplusplus -Dsparc -Dsun -Dunix -D__sparc__ -D__sun__ -D__unix__ -D__sparc -D__sun -D__unix -D__OPTIMIZE__ tt.cc /usr/tmp/cca16655.i
GNU CPP version 2.2.2 (sparc)
 /d/turlais/lib/gcc-lib/sun4/2.2.2/cc1plus /usr/tmp/cca16655.i -quiet -dumpbase tt.cc -O -version -o /usr/tmp/cca16655.s
GNU C++ version 2.2.2 (sparc) compiled by GNU C version 2.2.2.
 as -o tt.o /usr/tmp/cca16655.s
 /d/turlais/lib/gcc-lib/sun4/2.2.2/ld -e start -dc -dp /lib/crt0.o -L/d/turlais/lib/gcc-lib/sun4/2.2.2 -L/d/turlais/lib tt.o -lgcc -lc -lgcc
52 halley % 

-------------   Program    -------------------------------------

class symb;

class fwd_symb {
    public:
    fwd_symb *next;
    symb *fun;
    int i;
};

class symb {
public:

    symb *get_fwd_symb();
    char *name;
    fwd_symb *bindings;
    symb *fun;
    int i;
};

symb *symb::get_fwd_symb()
{
    fwd_symb *b = bindings;

    // When -O is on, a SEGV occurs here.

    while( b && b->fun == 0 )
	b = b->next;
    
    if( b)
	return fun ? fun->get_fwd_symb() : 0;
    else
	return b->fun ? b->fun->get_fwd_symb() : 0;
}

int main() {
    
    symb es;

    es.bindings = 0;

    symb *f = es.get_fwd_symb();
}