Bug 99789

There is a memory leak on failure to create an ir_constant in calculate_iterations in loop_controls.cpp.

If iter is NULL the method returns without deleting the allocated memory.

See below:

int
calculate_iterations(ir_rvalue *from, ir_rvalue *to, ir_rvalue *increment,
		     enum ir_expression_operation op)
{
   if (from == NULL || to == NULL || increment == NULL)
      return -1;

   void *mem_ctx = ralloc_context(NULL);

   ir_expression *const sub =
      new(mem_ctx) ir_expression(ir_binop_sub, from->type, to, from);

   ir_expression *const div =
      new(mem_ctx) ir_expression(ir_binop_div, sub->type, sub, increment);

   ir_constant *iter = div->constant_expression_value();

   if (iter == NULL)
      return -1;


If iter == NULL then I should be seeing something like:

   if (iter == NULL) {
      // sub & div  are created as emplacement new so delete is not required
      // unless meme_ctx has a destructor.

      ralloc_free(mem_ctx);
      return -1;
   }