jcf-write.c

gcc-2.95.3 Linux下最常用的C编译器

    case EXIT_BLOCK_EXPR:
      {
	struct jcf_block *label = state->labeled_blocks;
	if (TREE_OPERAND (exp, 1) != NULL) goto notimpl;
	while (label->u.labeled_block != TREE_OPERAND (exp, 0))
	  label = label->next;
	call_cleanups (label, state);
	emit_goto (label, state);
      }
      break;

    case PREDECREMENT_EXPR:  value = -1; post_op = 0;  goto increment;
    case PREINCREMENT_EXPR:  value =  1; post_op = 0;  goto increment;
    case POSTDECREMENT_EXPR: value = -1; post_op = 1;  goto increment;
    case POSTINCREMENT_EXPR: value =  1; post_op = 1;  goto increment;
    increment:

      exp = TREE_OPERAND (exp, 0);
      type = TREE_TYPE (exp);
      size = TYPE_IS_WIDE (type) ? 2 : 1;
      if ((TREE_CODE (exp) == VAR_DECL || TREE_CODE (exp) == PARM_DECL)
	  && ! TREE_STATIC (exp)
	  && TREE_CODE (type) == INTEGER_TYPE
	  && TYPE_PRECISION (type) == 32)
	{
	  if (target != IGNORE_TARGET && post_op)
	    emit_load (exp, state);
	  emit_iinc (exp, value, state);
	  if (target != IGNORE_TARGET && ! post_op)
	    emit_load (exp, state);
	  break;
	}
      if (TREE_CODE (exp) == COMPONENT_REF)
	{
	  generate_bytecode_insns (TREE_OPERAND (exp, 0), STACK_TARGET, state);
	  emit_dup (1, 0, state);
	  /* Stack:  ..., objectref, objectref. */
	  field_op (TREE_OPERAND (exp, 1), OPCODE_getfield, state);
	  NOTE_PUSH (size-1);
	  /* Stack:  ..., objectref, oldvalue. */
	  offset = 1;
	}
      else if (TREE_CODE (exp) == ARRAY_REF)
	{
	  generate_bytecode_insns (TREE_OPERAND (exp, 0), STACK_TARGET, state);
	  generate_bytecode_insns (TREE_OPERAND (exp, 1), STACK_TARGET, state);
	  emit_dup (2, 0, state);
	  /* Stack:  ..., array, index, array, index. */
	  jopcode = OPCODE_iaload + adjust_typed_op (TREE_TYPE (exp), 7);
	  RESERVE(1);
	  OP1 (jopcode);
	  NOTE_POP (2-size);
	  /* Stack:  ..., array, index, oldvalue. */
	  offset = 2;
	}
      else if (TREE_CODE (exp) == VAR_DECL || TREE_CODE (exp) == PARM_DECL)
	{
	  generate_bytecode_insns (exp, STACK_TARGET, state);
	  /* Stack:  ..., oldvalue. */
	  offset = 0;
	}
      else
	abort ();

      if (target != IGNORE_TARGET && post_op)
	emit_dup (size, offset, state);
      /* Stack, if ARRAY_REF:  ..., [result, ] array, index, oldvalue. */
      /* Stack, if COMPONENT_REF:  ..., [result, ] objectref, oldvalue. */
      /* Stack, otherwise:  ..., [result, ] oldvalue. */
      if (size == 1)
	push_int_const (value, state);
      else
	push_long_const (value, value >= 0 ? 0 : -1, state);
      NOTE_PUSH (size);
      emit_binop (OPCODE_iadd + adjust_typed_op (type, 3), type, state);
      if (target != IGNORE_TARGET && ! post_op)
	emit_dup (size, offset, state);
      /* Stack, if ARRAY_REF:  ..., [result, ] array, index, newvalue. */
      /* Stack, if COMPONENT_REF:  ..., [result, ] objectref, newvalue. */
      /* Stack, otherwise:  ..., [result, ] newvalue. */
      goto finish_assignment;

    case MODIFY_EXPR:
      {
	tree lhs = TREE_OPERAND (exp, 0);
	tree rhs = TREE_OPERAND (exp, 1);
	int offset = 0;

	/* See if we can use the iinc instruction. */
	if ((TREE_CODE (lhs) == VAR_DECL || TREE_CODE (lhs) == PARM_DECL)
	    && ! TREE_STATIC (lhs)
	    && TREE_CODE (TREE_TYPE (lhs)) == INTEGER_TYPE
	    && TYPE_PRECISION (TREE_TYPE (lhs)) == 32
	    && (TREE_CODE (rhs) == PLUS_EXPR || TREE_CODE (rhs) == MINUS_EXPR))
	  {
	    tree arg0 = TREE_OPERAND (rhs, 0);
	    tree arg1 = TREE_OPERAND (rhs, 1);
	    HOST_WIDE_INT min_value = -32768;
	    HOST_WIDE_INT max_value = 32767;
	    if (TREE_CODE (rhs) == MINUS_EXPR)
	      {
		min_value++;
		max_value++;
	      }
	    else if (arg1 == lhs)
	      {
		arg0 = arg1;
		arg1 = TREE_OPERAND (rhs, 0);
	      }
	    if (lhs == arg0 && TREE_CODE (arg1) == INTEGER_CST)
	      {
		HOST_WIDE_INT hi_value = TREE_INT_CST_HIGH (arg1);
		value = TREE_INT_CST_LOW (arg1);
		if ((hi_value == 0 && value <= max_value)
		    || (hi_value == -1 && value >= min_value))
		  {
		    if (TREE_CODE (rhs) == MINUS_EXPR)
		      value = -value;
		    emit_iinc (lhs, value, state);
		    break;
		  }
	      }
	  }

	if (TREE_CODE (lhs) == COMPONENT_REF)
	  {
	    generate_bytecode_insns (TREE_OPERAND (lhs, 0),
				     STACK_TARGET, state);
	    offset = 1;
	  }
	else if (TREE_CODE (lhs) == ARRAY_REF)
	  {
	    generate_bytecode_insns (TREE_OPERAND(lhs, 0),
				     STACK_TARGET, state);
	    generate_bytecode_insns (TREE_OPERAND(lhs, 1),
				     STACK_TARGET, state);
	    offset = 2;
	  }
	else
	  offset = 0;
	generate_bytecode_insns (rhs, STACK_TARGET, state);
	if (target != IGNORE_TARGET)
	  emit_dup (TYPE_IS_WIDE (type) ? 2 : 1 , offset, state);
	exp = lhs;
      }
      /* FALLTHOUGH */

    finish_assignment:
      if (TREE_CODE (exp) == COMPONENT_REF)
	{
	  tree field = TREE_OPERAND (exp, 1);
	  if (! FIELD_STATIC (field))
	    NOTE_POP (1);
	  field_op (field,
		    FIELD_STATIC (field) ? OPCODE_putstatic : OPCODE_putfield,
		    state);

	  NOTE_POP (TYPE_IS_WIDE (TREE_TYPE (field)) ? 2 : 1);
	}
      else if (TREE_CODE (exp) == VAR_DECL
	       || TREE_CODE (exp) == PARM_DECL)
	{
	  if (FIELD_STATIC (exp))
	    {
	      field_op (exp, OPCODE_putstatic, state);
	      NOTE_POP (TYPE_IS_WIDE (TREE_TYPE (exp)) ? 2 : 1);
	    }
	  else
	    emit_store (exp, state);
	}
      else if (TREE_CODE (exp) == ARRAY_REF)
	{
	  jopcode = OPCODE_iastore + adjust_typed_op (TREE_TYPE (exp), 7);
	  RESERVE(1);
	  OP1 (jopcode);
	  NOTE_POP (TYPE_IS_WIDE (TREE_TYPE (exp)) ? 4 : 3);
	}
      else
	fatal ("internal error (bad lhs to MODIFY_EXPR)");
      break;
    case PLUS_EXPR:
      jopcode = OPCODE_iadd;
      goto binop;
    case MINUS_EXPR:
      jopcode = OPCODE_isub;
      goto binop;
    case MULT_EXPR:
      jopcode = OPCODE_imul;
      goto binop;
    case TRUNC_DIV_EXPR:
    case RDIV_EXPR:
      jopcode = OPCODE_idiv;
      goto binop;
    case TRUNC_MOD_EXPR:
      jopcode = OPCODE_irem;
      goto binop;
    case LSHIFT_EXPR:   jopcode = OPCODE_ishl;   goto binop;
    case RSHIFT_EXPR:   jopcode = OPCODE_ishr;   goto binop;
    case URSHIFT_EXPR:  jopcode = OPCODE_iushr;  goto binop;
    case TRUTH_AND_EXPR:
    case BIT_AND_EXPR:  jopcode = OPCODE_iand;   goto binop;
    case TRUTH_OR_EXPR:
    case BIT_IOR_EXPR:  jopcode = OPCODE_ior;    goto binop;
    case TRUTH_XOR_EXPR:
    case BIT_XOR_EXPR:  jopcode = OPCODE_ixor;   goto binop;
    binop:
    {
      tree arg0 = TREE_OPERAND (exp, 0);
      tree arg1 = TREE_OPERAND (exp, 1);
      jopcode += adjust_typed_op (type, 3);
      if (arg0 == arg1 && TREE_CODE (arg0) == SAVE_EXPR)
	{
	  /* fold may (e.g) convert 2*x to x+x. */
	  generate_bytecode_insns (TREE_OPERAND (arg0, 0), target, state);
	  emit_dup (TYPE_PRECISION (TREE_TYPE (arg0)) > 32 ? 2 : 1, 0, state);
	}
      else
	{
	  generate_bytecode_insns (arg0, target, state);
	  generate_bytecode_insns (arg1, target, state);
	}
      /* For most binary operations, both operands and the result have the
	 same type.  Shift operations are different.  Using arg1's type
	 gets us the correct SP adjustment in all casesd. */
      if (target == STACK_TARGET)
	emit_binop (jopcode, TREE_TYPE (arg1), state);
      break;
    }
    case TRUTH_NOT_EXPR:
    case BIT_NOT_EXPR:
      generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
      if (target == STACK_TARGET)
	{
	  int is_long = TYPE_PRECISION (TREE_TYPE (exp)) > 32;
	  push_int_const (TREE_CODE (exp) == BIT_NOT_EXPR ? -1 : 1, state); 
	  RESERVE (2);
	  if (is_long)
	    OP1 (OPCODE_i2l);
	  NOTE_PUSH (1 + is_long);
	  OP1 (OPCODE_ixor + is_long);
	  NOTE_POP (1 + is_long);
	}
      break;
    case NEGATE_EXPR:
      jopcode = OPCODE_ineg;
      jopcode += adjust_typed_op (type, 3);
      generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
      if (target == STACK_TARGET)
	emit_unop (jopcode, type, state);
      break;
    case INSTANCEOF_EXPR:
      {
	int index = find_class_constant (&state->cpool, TREE_OPERAND (exp, 1));
	generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
	RESERVE (3);
	OP1 (OPCODE_instanceof);
	OP2 (index);
      }
      break;
    case CONVERT_EXPR:
    case NOP_EXPR:
    case FLOAT_EXPR:
    case FIX_TRUNC_EXPR:
      {
	tree src = TREE_OPERAND (exp, 0);
	tree src_type = TREE_TYPE (src);
	tree dst_type = TREE_TYPE (exp);
	generate_bytecode_insns (TREE_OPERAND (exp, 0), target, state);
	if (target == IGNORE_TARGET || src_type == dst_type)
	  break;
	if (TREE_CODE (dst_type) == POINTER_TYPE)
	  {
	    if (TREE_CODE (exp) == CONVERT_EXPR)
	      {
		int index = find_class_constant (&state->cpool, TREE_TYPE (dst_type));
		RESERVE (3);
		OP1 (OPCODE_checkcast);
		OP2 (index);
	      }
	  }
	else /* Convert numeric types. */
	  {
	    int wide_src = TYPE_PRECISION (src_type) > 32;
	    int wide_dst = TYPE_PRECISION (dst_type) > 32;
	    NOTE_POP (1 + wide_src);
	    RESERVE (1);
	    if (TREE_CODE (dst_type) == REAL_TYPE)
	      {
		if (TREE_CODE (src_type) == REAL_TYPE)
		  OP1 (wide_dst ? OPCODE_f2d : OPCODE_d2f);
		else if (TYPE_PRECISION (src_type) == 64)
		  OP1 (OPCODE_l2f + wide_dst);
		else
		  OP1 (OPCODE_i2f + wide_dst);
	      }
	    else /* Convert to integral type. */
	      {
		if (TREE_CODE (src_type) == REAL_TYPE)
		  OP1 (OPCODE_f2i + wide_dst + 3 * wide_src);
		else if (wide_dst)
		  OP1 (OPCODE_i2l);
		else if (wide_src)
		  OP1 (OPCODE_l2i);
		if (TYPE_PRECISION (dst_type) < 32)
		  {
		    RESERVE (1);
		    /* Already converted to int, if needed. */
		    if (TYPE_PRECISION (dst_type) <= 8)
		      OP1 (OPCODE_i2b);
		    else if (TREE_UNSIGNED (dst_type))
		      OP1 (OPCODE_i2c);
		    else
		      OP1 (OPCODE_i2s);
		  }
	      }
	    NOTE_PUSH (1 + wide_dst);
	  }
      }
      break;

    case CLEANUP_POINT_EXPR:
      {
	struct jcf_block *save_labeled_blocks = state->labeled_blocks;
	int can_complete = CAN_COMPLETE_NORMALLY (TREE_OPERAND (exp, 0));
	generate_bytecode_insns (TREE_OPERAND (exp, 0), IGNORE_TARGET, state);
	if (target != IGNORE_TARGET)
	  abort ();
	while (state->labeled_blocks != save_labeled_blocks)
	  {
	    struct jcf_block *finished_label = NULL;
	    tree return_link;
	    tree exception_type = build_pointer_type (throwable_type_node);
	    tree exception_decl = build_decl (VAR_DECL, NULL_TREE,
					      exception_type);
	    struct jcf_block *end_label = get_jcf_label_here (state);
	    struct jcf_block *label = state->labeled_blocks;
	    struct jcf_handler *handler;
	    tree cleanup = label->u.labeled_block;
	    state->labeled_blocks = label->next;
	    state->num_finalizers--;
	    if (can_complete)
	      {
		finished_label = gen_jcf_label (state);
		emit_jsr (label, state);
		emit_goto (finished_label, state);
		if (! CAN_COMPLETE_NORMALLY (cleanup))
		  can_complete = 0;
	      }
	    handler = alloc_handler (label->v.start_label, end_label, state);
	    handler->type = NULL_TREE;
	    localvar_alloc (exception_decl, state);
	    NOTE_PUSH (1);
            emit_store (exception_decl, state);
	    emit_jsr (label, state);
	    emit_load (exception_decl, state);
	    RESERVE (1);
	    OP1 (OPCODE_athrow);
	    NOTE_POP (1);

	    /* The finally block. */
	    return_link = build_decl (VAR_DECL, NULL_TREE,
				      return_address_type_node);
	    define_jcf_label (label, state);
	    NOTE_PUSH (1);
	    localvar_alloc (return_link, state);
	    emit_store (return_link, state);
	    generate_bytecode_insns (cleanup, IGNORE_TARGET, state);
	    maybe_wide (OPCODE_ret, DECL_LOCAL_INDEX (return_link), state);
	    localvar_free (return_link, state);
	    localvar_free (exception_decl, state);
	    if (finished_label != NULL)
	      define_jcf_label (finished_label, state);
	  }
      }
      break;

    case WITH_CLEANUP_EXPR:
      {
	struct jcf_block *label;
	generate_bytecode_insns (TREE_OPERAND (exp, 0), IGNORE_TARGET, state);
	label = gen_jcf_label (state);
	label->pc = PENDING_CLEANUP_PC;
	label->next = state->labeled_blocks;
	state->labeled_blocks = label;
	state->num_finalizers++;
	label->u.labeled_block = TREE_OPERAND (exp, 2);
	label->v.start_label = get_jcf_label_here (state);
	if (target != IGNORE_TARGET)
	  abort ();
      }
      break;

    case TRY_EXPR:
      {
	tree try_clause = TREE_OPERAND (exp, 0);
	struct jcf_block *start_label = get_jcf_label_here (state);
	struct jcf_block *end_label;  /* End of try clause. */
	struct jcf_block *finished_label = gen_jcf_label (state);
	tree clause = TREE_OPERAND (exp, 1);
	if (target != IGNORE_TARGET)
	  abort ();
	generate_bytecode_insns (try_clause, IGNORE_TARGET, state);
	end_label = get_jcf_label_here (state);
	if (CAN_COMPLETE_NORMALLY (try_clause))
	  emit_goto (finished_label, state);
	while (clause != NULL_TREE)
	  {
	    tree catch_clause = TREE_OPERAND (clause, 0);
	    tree exception_decl = BLOCK_EXPR_DECLS (catch_clause);
	    struct jcf_handler *handler = alloc_handler (start_label, end_label, state);
	    if (exception_decl == NULL_TREE)
	      handler->type = NULL_TREE;
	    else
	      handler->type = TREE_TYPE (TREE_TYPE (exception_decl));
	    generate_bytecode_insns (catch_clause, IGNORE_TARGET, state);
	    clause = TREE_CHAIN (clause);
	    if (CAN_COMPLETE_NORMALLY (catch_clause) && clause != NULL_TREE)
	      emit_goto (finished_label, state);
	  }
	define_jcf_label (finished_label, state);
      }
      break;
    case TRY_FINALLY_EXPR:
      {
	tree try_block = TREE_OPERAND (exp, 0);
	tree finally = TREE_OPERAND (exp, 1);
	struct jcf_block *finished_label = gen_jcf_label (state);
	struct jcf_block *finally_label = gen_jcf_label (state);
	struct jcf_block *start_label = get_jcf_label_here (state);
	tree return_link = build_decl (VAR_DECL, NULL_TREE,
				       return_address_type_node);
	tree exception_type = build_pointer_type (throwable_type_node);
	tree exception_decl = build_decl (VAR_DECL, NULL_TREE, exception_type);
	struct jcf_handler *handler;

	finally_label->pc = PENDING_CLEANUP_PC;
	finally_label->next = state->labeled_blocks;
	state->labeled_blocks = finally_label;
	state->num_finalizers++;

	generate_bytecode_insns (try_block, target, state);
	if (state->labeled_blocks != finally_label)
	  abort();
	state->labeled_blocks = finally_label->next;
	emit_jsr (finally_label, state);
	if (CAN_COMPLETE_NORMALLY (try_block))
	  emit_goto (finished_label, state);

	/* Handle exceptions. */
	localvar_alloc (return_link, state);
	handler = alloc_handler (start_label, NULL_TREE, state);
	handler->end_