verify.c

gcc-2.95.3 Linux下最常用的C编译器

	      /* FIXME: If we exit a subroutine via a throw, we might
		 have returned to an earlier caller.  Obviously a
		 "ret" can only return one level, but a throw may
		 return many levels.*/
	      current_subr = caller;

	      if (RETURN_MAP_ADJUSTED (ret_map))
		{
		  /* Since we are done with this subroutine , set up
		     the (so far known) return address as pending -
		     with the merged type state. */
		  for ( ; tmp != NULL_TREE;  tmp = TREE_CHAIN (tmp))
		    {
		      tree return_label = TREE_VALUE (tmp);
		      tree return_state = LABEL_TYPE_STATE (return_label);
		      if (return_state == NULL_TREE)
			{
			  /* This means means we had not verified the
			     subroutine earlier, so this is the first jsr to
			     call it.  In this case, the type_map of the return
			     address is just the current type_map - and that
			     is handled by the following PUSH_PENDING. */
			}
		      else
			{
			  /* In this case we have to do a merge.  But first
			     restore the type_map for unused slots to those
			     that were in effect at the jsr. */
			  for (index = size;  --index >= 0; )
			    {
			      type_map[index] = TREE_VEC_ELT (ret_map, index);
			      if (type_map[index] == TYPE_UNUSED)
				type_map[index]
				  = TREE_VEC_ELT (return_state, index);
			    }
			}
		      PUSH_PENDING (return_label);
		    }
		}
	    }
	}
      if (PC == INVALID_PC)
	{
	  label = pending_blocks;
	  if (label == NULL_TREE)
	    break;  /* We're done! */
	  pending_blocks = LABEL_PENDING_CHAIN (label);
	  LABEL_CHANGED (label) = 0;

	  if (LABEL_IN_SUBR (label))
	    current_subr = LABEL_SUBR_START (label);
	  else
	    current_subr = NULL_TREE;

	  /* Restore type_map and stack_pointer from
	     LABEL_TYPE_STATE (label), and continue
	     compiling from there. */
	  load_type_state (label);
	  PC = LABEL_PC (label);
	}
      else if (PC >= length)
	VERIFICATION_ERROR ("falling through end of method");

      /* fprintf (stderr, "** %d\n", PC); */

      oldpc = PC;

      if (!(instruction_bits [PC] & BCODE_INSTRUCTION_START) && ! wide)
	VERIFICATION_ERROR ("PC not at instruction start");

      instruction_bits[PC] |= BCODE_VERIFIED;

      eh_ranges = find_handler (oldpc);

      op_code = byte_ops[PC++];
      switch (op_code)
	{
	  int is_static, is_putting;
	case OPCODE_nop:
	  break;
	case OPCODE_iconst_m1:
	case OPCODE_iconst_0:	case OPCODE_iconst_1:	case OPCODE_iconst_2:
	case OPCODE_iconst_3:	case OPCODE_iconst_4:	case OPCODE_iconst_5:
	  i = op_code - OPCODE_iconst_0;
	  goto push_int;
	push_int:
	  if (byte_ops[PC] == OPCODE_newarray
	      || byte_ops[PC] == OPCODE_newarray)
	    int_value = i;
	  push_type (int_type_node);  break;
	case OPCODE_lconst_0:	case OPCODE_lconst_1:
	  push_type (long_type_node);  break;
	case OPCODE_fconst_0:	case OPCODE_fconst_1:	case OPCODE_fconst_2:
	  push_type (float_type_node);  break;
	case OPCODE_dconst_0:	case OPCODE_dconst_1:
	  push_type (double_type_node);  break;
	case OPCODE_bipush:
	  i = IMMEDIATE_s1;
	  goto push_int;
	case OPCODE_sipush:
	  i = IMMEDIATE_s2;
	  goto push_int;
	case OPCODE_iload:  type = int_type_node;  goto general_load;
	case OPCODE_lload:  type = long_type_node;  goto general_load;
	case OPCODE_fload:  type = float_type_node;  goto general_load;
	case OPCODE_dload:  type = double_type_node;  goto general_load;
	case OPCODE_aload:  type = ptr_type_node;  goto general_load;
	general_load:
	index = wide ? IMMEDIATE_u2 : IMMEDIATE_u1;
	wide = 0;
	goto load;
	case OPCODE_iload_0:  type = int_type_node;  index = 0; goto load;
	case OPCODE_iload_1:  type = int_type_node;  index = 1; goto load;
	case OPCODE_iload_2:  type = int_type_node;  index = 2; goto load;
	case OPCODE_iload_3:  type = int_type_node;  index = 3; goto load;
	case OPCODE_lload_0:  type = long_type_node; index = 0; goto load;
	case OPCODE_lload_1:  type = long_type_node; index = 1; goto load;
	case OPCODE_lload_2:  type = long_type_node; index = 2; goto load;
	case OPCODE_lload_3:  type = long_type_node; index = 3; goto load;
	case OPCODE_fload_0:  type = float_type_node; index = 0; goto load;
	case OPCODE_fload_1:  type = float_type_node; index = 1; goto load;
	case OPCODE_fload_2:  type = float_type_node; index = 2; goto load;
	case OPCODE_fload_3:  type = float_type_node; index = 3; goto load;
	case OPCODE_dload_0: type = double_type_node; index = 0; goto load;
	case OPCODE_dload_1: type = double_type_node; index = 1; goto load;
	case OPCODE_dload_2: type = double_type_node; index = 2; goto load;
	case OPCODE_dload_3: type = double_type_node; index = 3; goto load;
	case OPCODE_aload_0:  type = ptr_type_node;  index = 0;  goto load;
	case OPCODE_aload_1:  type = ptr_type_node;  index = 1;  goto load;
	case OPCODE_aload_2:  type = ptr_type_node;  index = 2;  goto load;
	case OPCODE_aload_3:  type = ptr_type_node;  index = 3;  goto load;
	load:
	if (index < 0
	    || (index + TYPE_IS_WIDE (type)
		>= DECL_MAX_LOCALS (current_function_decl)))
	  VERIFICATION_ERROR ("invalid local variable index in load");
	tmp = type_map[index];
	if (tmp == TYPE_UNKNOWN || tmp == TYPE_SECOND
	    || (TYPE_IS_WIDE (type)
		&& type_map[index+1] != void_type_node)
	    || (type == ptr_type_node
		? TREE_CODE (tmp) != POINTER_TYPE
		: type == int_type_node
		? (! INTEGRAL_TYPE_P (tmp) || TYPE_PRECISION (tmp) > 32)
		: type != tmp))
	  VERIFICATION_ERROR("invalid local variable type in load");
	push_type (tmp);
	goto note_used;
	case OPCODE_istore:  type = int_type_node;  goto general_store;
	case OPCODE_lstore:  type = long_type_node;  goto general_store;
	case OPCODE_fstore:  type = float_type_node;  goto general_store;
	case OPCODE_dstore:  type = double_type_node;  goto general_store;
	case OPCODE_astore:  type = ptr_type_node;  goto general_store;
	general_store:
	index = wide ? IMMEDIATE_u2 : IMMEDIATE_u1;
	wide = 0;
	goto store;
	case OPCODE_istore_0:  type = int_type_node; index = 0; goto store;
	case OPCODE_istore_1:  type = int_type_node; index = 1; goto store;
	case OPCODE_istore_2:  type = int_type_node; index = 2; goto store;
	case OPCODE_istore_3:  type = int_type_node; index = 3; goto store;
	case OPCODE_lstore_0:  type = long_type_node; index=0; goto store;
	case OPCODE_lstore_1:  type = long_type_node; index=1; goto store;
	case OPCODE_lstore_2:  type = long_type_node; index=2; goto store;
	case OPCODE_lstore_3:  type = long_type_node; index=3; goto store;
	case OPCODE_fstore_0:  type=float_type_node; index=0; goto store;
	case OPCODE_fstore_1:  type=float_type_node; index=1; goto store;
	case OPCODE_fstore_2:  type=float_type_node; index=2; goto store;
	case OPCODE_fstore_3:  type=float_type_node; index=3; goto store;
	case OPCODE_dstore_0:  type=double_type_node; index=0; goto store;
	case OPCODE_dstore_1:  type=double_type_node; index=1; goto store;
	case OPCODE_dstore_2:  type=double_type_node; index=2; goto store;
	case OPCODE_dstore_3:  type=double_type_node; index=3; goto store;
	case OPCODE_astore_0:  type = ptr_type_node; index = 0; goto store;
	case OPCODE_astore_1:  type = ptr_type_node; index = 1; goto store;
	case OPCODE_astore_2:  type = ptr_type_node; index = 2; goto store;
	case OPCODE_astore_3:  type = ptr_type_node; index = 3; goto store;
	store:
	if (index < 0
	    || (index + TYPE_IS_WIDE (type)
		>= DECL_MAX_LOCALS (current_function_decl)))
	  {
	    VERIFICATION_ERROR ("invalid local variable index in store");
	    return 0;
	  }
	type = pop_type (type);
	type_map[index] = type;

	/* If local variable changed, we need to reconsider eh handlers. */
	prev_eh_ranges = NULL_EH_RANGE;

	/* Allocate decl and rtx for this variable now, so if we're not
	   optmizing, we get a temporary that survives the whole method. */
	find_local_variable (index, type, oldpc);

        if (TYPE_IS_WIDE (type))
          type_map[index+1] = TYPE_SECOND;
	/* ... fall through to note_used ... */
	note_used:
	  /* For store or load, note that local variable INDEX is used.
	     This is needed to verify try-finally sub-routines. */
	  if (current_subr)
	    {
	      tree vec = LABEL_RETURN_TYPE_STATE (current_subr);
	      tree subr_vec = LABEL_TYPE_STATE (current_subr);
	      int len = 1 + TYPE_IS_WIDE (type);
	      while (--len >= 0)
		{
		  if (TREE_VEC_ELT (vec, index) == TYPE_UNUSED)
		    TREE_VEC_ELT (vec, index) = TREE_VEC_ELT (subr_vec, index);
		}
	    }
	break;
	case OPCODE_iadd:
	case OPCODE_iand:
	case OPCODE_idiv:
	case OPCODE_imul:
	case OPCODE_ior:
	case OPCODE_irem:
	case OPCODE_ishl:
	case OPCODE_ishr:
	case OPCODE_isub:
	case OPCODE_iushr:
	case OPCODE_ixor:
	  type = int_type_node;  goto binop;
	case OPCODE_ineg:
	case OPCODE_i2c:
	case OPCODE_i2b:
	case OPCODE_i2s:
	  type = int_type_node;  goto unop;
	case OPCODE_ladd:
	case OPCODE_land:
	case OPCODE_ldiv:
	case OPCODE_lsub:
	case OPCODE_lmul:
	case OPCODE_lrem:
	case OPCODE_lor:
	case OPCODE_lxor:
	  type = long_type_node;  goto binop;
	case OPCODE_lneg:
	  type = long_type_node;  goto unop;
	case OPCODE_fadd:	case OPCODE_fsub:
	case OPCODE_fmul:	case OPCODE_fdiv:	case OPCODE_frem:
	  type = float_type_node;  goto binop;
	case OPCODE_fneg:
	  type = float_type_node;  goto unop;
	case OPCODE_dadd:	case OPCODE_dsub:
	case OPCODE_dmul:	case OPCODE_ddiv:	case OPCODE_drem:
	  type = double_type_node;  goto binop;
	case OPCODE_dneg:
	  type = double_type_node;  goto unop;
	unop:
	  pop_type (type);
	  push_type (type);
	  break;
	binop:
	  pop_type (type);
	  pop_type (type);
	  push_type (type);
	  break;
	case OPCODE_lshl:
	case OPCODE_lshr:
	case OPCODE_lushr:
	  pop_type (int_type_node);
	  pop_type (long_type_node);
	  push_type (long_type_node);
	  break;
	case OPCODE_iinc:
	  index = wide ? IMMEDIATE_u2 : IMMEDIATE_u1;
	  PC += wide + 1;
	  wide = 0;
	  if (index < 0 || index >= DECL_MAX_LOCALS (current_function_decl))
	    VERIFICATION_ERROR ("invalid local variable index in iinc");
	  tmp = type_map[index];
	  if (! INTEGRAL_TYPE_P (tmp) || TYPE_PRECISION (tmp) > 32)
	    VERIFICATION_ERROR ("invalid local variable type in iinc");
	  break;
	case OPCODE_i2l:
	  pop_type (int_type_node);    push_type (long_type_node);   break;
	case OPCODE_i2f:
	  pop_type (int_type_node);    push_type (float_type_node);  break;
	case OPCODE_i2d:
	  pop_type (int_type_node);    push_type (double_type_node); break;
	case OPCODE_l2i:
	  pop_type (long_type_node);   push_type (int_type_node);    break;
	case OPCODE_l2f:
	  pop_type (long_type_node);   push_type (float_type_node);  break;
	case OPCODE_l2d:
	  pop_type (long_type_node);   push_type (double_type_node); break;
	case OPCODE_f2i:
	  pop_type (float_type_node);  push_type (int_type_node);    break;
	case OPCODE_f2l:
	  pop_type (float_type_node);  push_type (long_type_node);   break;
	case OPCODE_f2d:
	  pop_type (float_type_node);  push_type (double_type_node); break;
	case OPCODE_d2i:
	  pop_type (double_type_node); push_type (int_type_node);    break;
	case OPCODE_d2l:
	  pop_type (double_type_node); push_type (long_type_node);   break;
	case OPCODE_d2f:
	  pop_type (double_type_node); push_type (float_type_node);  break;
	case OPCODE_lcmp:
	  type = long_type_node;  goto compare;
	case OPCODE_fcmpl:
	case OPCODE_fcmpg:
	  type = float_type_node;  goto compare;
	case OPCODE_dcmpl:
	case OPCODE_dcmpg:
	  type = double_type_node;  goto compare;
	compare:
	  pop_type (type);  pop_type (type);
	  push_type (int_type_node);  break;
	case OPCODE_ifeq:
	case OPCODE_ifne:
	case OPCODE_iflt:
	case OPCODE_ifge:
	case OPCODE_ifgt:
	case OPCODE_ifle:
	  pop_type (int_type_node);  goto cond;
	case OPCODE_ifnull:
	case OPCODE_ifnonnull:
	  pop_type (ptr_type_node ); goto cond;
	case OPCODE_if_icmpeq:
	case OPCODE_if_icmpne:
	case OPCODE_if_icmplt:
	case OPCODE_if_icmpge:
	case OPCODE_if_icmpgt:
	case OPCODE_if_icmple:
	  pop_type (int_type_node);  pop_type (int_type_node);  goto cond;
	case OPCODE_if_acmpeq:
	case OPCODE_if_acmpne:
	  pop_type (object_ptr_type_node);  pop_type (object_ptr_type_node);
	  goto cond;
	cond:
	  PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s2));
	  break;
	case OPCODE_goto:
	  PUSH_PENDING (lookup_label (oldpc + IMMEDIATE_s2));
	  INVALIDATE_PC;
	  break;
	case OPCODE_wide:
	  switch (byte_ops[PC])
	    {
	    case OPCODE_iload:  case OPCODE_lload:
	    case OPCODE_fload:  case OPCODE_dload:  case OPCODE_aload:
	    case OPCODE_istore:  case OPCODE_lstore:
	    case OPCODE_fstore:  case OPCODE_dstore:  case OPCODE_astore:
	    case OPCODE_iinc:
	    case OPCODE_ret:
	      wide = 1;
	      break;
	    default:
	      VERIFICATION_ERROR ("invalid use of wide instruction");
	    }
	  break;
	case OPCODE_return:   type = void_type_node;   goto ret;
	case OPCODE_ireturn:
	  if ((TREE_CODE (return_type) == BOOLEAN_TYPE
	       || TREE_CODE (return_type) == CHAR_TYPE
	       || TREE_CODE (return_type) == INTEGER_TYPE)
	      && TYPE_PRECISION (return_type) <= 32)
	    type = return_type;
	  else
	    type = NULL_TREE;
	  goto ret;
	case OPCODE_lreturn:  type = long_type_node;   goto ret;
	case OPCODE_freturn:  type = float_type_node;  goto ret;
	case OPCODE_dreturn:  type = double_type_node; goto ret;
	case OPCODE_areturn:
	  if (TREE_CODE (return_type) == POINTER_TYPE)
	    type = return_type;
	  else
	    type = NULL_TREE;
	  goto ret;
	ret:
	  if (type != return_type)
	    VERIFICATION_ERROR ("incorrect ?return opcode");
	  if (type != void_type_node)
	    {
	      if (pop_type_0 (type) == NULL_TREE)
		VERIFICATION_ERROR ("return value has wrong type");
	    }
	  INVALIDATE_PC;
	  break;
	case OPCODE_getstatic: is_putting = 0;  is_static = 1;  goto field;
	case OPCODE_putstatic: is_putting = 1;  is_static = 1;  goto field;
	case OPCODE_getfield:  is_putting = 0;  is_static = 0;  goto field;
	case OPCODE_putfield:  is_putting = 1;  is_static = 0;  goto field;
	field:
	  {
	    int index = IMMEDIATE_u2;
	    tree field_signature = COMPONENT_REF_SIGNATURE (&current_jcf->cpool, index);
	    tree field_type = get_type_from_signature (field_signature);
	    if (is_putting)
	      pop_type (field_type);
	    if (! is_static)
	      {
		int clindex = COMPONENT_REF_CLASS_INDEX (&current_jcf->cpool,
							index);
		tree self_type = get_class_constant (current_jcf, clindex);
		/* Defer actual checking until next pass. */
		if (pop_type_0 (self_type) == NULL_TREE)
		  VERIFICATION_ERROR ("incorrect type for field reference");
	      }
	    if (! is_putting)
	      push_type (field_type);
	    break;
	  }
	case OPCODE_new:
	  push_type (get_class_constant (jcf, IMMEDIATE_u2));
	  break;
	case OPCODE_dup:     type_stack_dup (1, 0);  break;
	case OPCODE_dup_x1:  type_stack_dup (1, 1);  break;
	case OPCODE_dup_x2:  type_stack_dup (1, 2);  break;
	case OPCODE_dup2:    type_stack_dup (2, 0);  break;
	case OPCODE_dup2_x1: type_stack_dup (2, 1);  break;
	case OPCODE_dup2_x2: type_stack_dup (2, 2);  break;
	case OPCODE_pop:  index = 1;  goto pop;
	case OPCODE_pop2: index = 2;  goto pop;
	pop:
	  if (stack_pointer < index)
	    VERIFICATION_ERROR ("stack underflow");
	  stack_pointer -= index;
	  break;
	case OPCODE_swap:
	  if (stack_pointer < 2)
	    VERIFICATION_ERROR ("stack underflow (in swap)");
	  else
	    {
	      tree type1 = stack_type_map[stack_pointer - 1];
	      tree type2 = stack_type_map[stack_pointer - 2];
	      if (type1 == void_type_node || type2 == void_type_node)
		VERIFICATION_ERROR ("verifier (swap):  double or long value");
	      stack_type_map[stack_pointer - 2] = type1;
	      stack_type_map[stack_pointer - 1] = type2;
	    }
	  break;
	case OPCODE_ldc:   index = IMMEDIATE_u1;  goto ldc;
	case OPCODE_ldc2_w:
	case OPCODE_ldc_w:
	  index = IMMEDIATE_u2;  goto ldc;
	ldc:
	  if (index <= 0 || index >= JPOOL_SIZE(current_jcf))
	    VERIFICATION_ERROR ("bad constant pool index in ldc");
	  int_value = -1;
	  switch (JPOOL_TAG (current_jcf, index) & ~CONSTANT_ResolvedFlag)
	    {
	    case CONSTANT_Integer:  type = int_type_node;  goto check_ldc;
	    case CONSTANT_Float:    type = float_type_node;  goto check_ldc;