src/hotspot/share/classfile/stackMapTable.hpp
changeset 47216 71c04702a3d5
parent 43179 06ccf3bfd0a3
child 49449 ef5d5d343e2a
equal deleted inserted replaced
47215:4ebc2e2fb97c 47216:71c04702a3d5
       
     1 /*
       
     2  * Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
       
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
       
     4  *
       
     5  * This code is free software; you can redistribute it and/or modify it
       
     6  * under the terms of the GNU General Public License version 2 only, as
       
     7  * published by the Free Software Foundation.
       
     8  *
       
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
       
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
       
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
       
    12  * version 2 for more details (a copy is included in the LICENSE file that
       
    13  * accompanied this code).
       
    14  *
       
    15  * You should have received a copy of the GNU General Public License version
       
    16  * 2 along with this work; if not, write to the Free Software Foundation,
       
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
       
    18  *
       
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
       
    20  * or visit www.oracle.com if you need additional information or have any
       
    21  * questions.
       
    22  *
       
    23  */
       
    24 
       
    25 #ifndef SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP
       
    26 #define SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP
       
    27 
       
    28 #include "classfile/stackMapFrame.hpp"
       
    29 #include "classfile/verifier.hpp"
       
    30 #include "memory/allocation.hpp"
       
    31 #include "oops/constantPool.hpp"
       
    32 #include "oops/method.hpp"
       
    33 #include "utilities/bytes.hpp"
       
    34 #include "utilities/globalDefinitions.hpp"
       
    35 
       
    36 class StackMapReader;
       
    37 
       
    38 // StackMapTable class is the StackMap table used by type checker
       
    39 class StackMapTable : public StackObj {
       
    40  private:
       
    41   // Logically, the _frame_count (as well as many fields in the StackFrame)
       
    42   // should be a u2, but if we defined the variable as that type it will
       
    43   // be difficult to detect/recover from overflow or underflow conditions.
       
    44   // Widening the type and making it signed will help detect these.
       
    45   int32_t              _code_length;
       
    46   int32_t              _frame_count;     // Stackmap frame count
       
    47   StackMapFrame**       _frame_array;
       
    48 
       
    49  public:
       
    50   StackMapTable(StackMapReader* reader, StackMapFrame* init_frame,
       
    51                 u2 max_locals, u2 max_stack,
       
    52                 char* code_data, int code_len, TRAPS);
       
    53 
       
    54   inline int32_t get_frame_count() const { return _frame_count; }
       
    55   inline int get_offset(int index) const {
       
    56     return _frame_array[index]->offset();
       
    57   }
       
    58 
       
    59   // Match and/or update current_frame to the frame in stackmap table with
       
    60   // specified offset. Return true if the two frames match.
       
    61   bool match_stackmap(
       
    62     StackMapFrame* current_frame, int32_t offset,
       
    63     bool match, bool update, ErrorContext* ctx, TRAPS) const;
       
    64   // Match and/or update current_frame to the frame in stackmap table with
       
    65   // specified offset and frame index. Return true if the two frames match.
       
    66   bool match_stackmap(
       
    67     StackMapFrame* current_frame, int32_t offset, int32_t frame_index,
       
    68     bool match, bool update, ErrorContext* ctx, TRAPS) const;
       
    69 
       
    70   // Check jump instructions. Make sure there are no uninitialized
       
    71   // instances on backward branch.
       
    72   void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const;
       
    73 
       
    74   // The following methods are only used inside this class.
       
    75 
       
    76   // Returns the frame array index where the frame with offset is stored.
       
    77   int get_index_from_offset(int32_t offset) const;
       
    78 
       
    79   void print_on(outputStream* str) const;
       
    80 };
       
    81 
       
    82 class StackMapStream : StackObj {
       
    83  private:
       
    84   Array<u1>* _data;
       
    85   int _index;
       
    86  public:
       
    87   StackMapStream(Array<u1>* ah)
       
    88     : _data(ah), _index(0) {
       
    89   }
       
    90   u1 get_u1(TRAPS) {
       
    91     if (_data == NULL || _index >= _data->length()) {
       
    92       stackmap_format_error("access beyond the end of attribute", CHECK_0);
       
    93     }
       
    94     return _data->at(_index++);
       
    95   }
       
    96   u2 get_u2(TRAPS) {
       
    97     if (_data == NULL || _index >= _data->length() - 1) {
       
    98       stackmap_format_error("access beyond the end of attribute", CHECK_0);
       
    99     }
       
   100     u2 res = Bytes::get_Java_u2(_data->adr_at(_index));
       
   101     _index += 2;
       
   102     return res;
       
   103   }
       
   104   bool at_end() {
       
   105     return (_data == NULL) || (_index == _data->length());
       
   106   }
       
   107   static void stackmap_format_error(const char* msg, TRAPS);
       
   108 };
       
   109 
       
   110 class StackMapReader : StackObj {
       
   111  private:
       
   112   // information about the class and method
       
   113   constantPoolHandle  _cp;
       
   114   ClassVerifier* _verifier;
       
   115   StackMapStream* _stream;
       
   116   char* _code_data;
       
   117   int32_t _code_length;
       
   118 
       
   119   // information get from the attribute
       
   120   int32_t  _frame_count;       // frame count
       
   121 
       
   122   int32_t chop(VerificationType* locals, int32_t length, int32_t chops);
       
   123   VerificationType parse_verification_type(u1* flags, TRAPS);
       
   124   void check_verification_type_array_size(
       
   125       int32_t size, int32_t max_size, TRAPS) {
       
   126     if (size < 0 || size > max_size) {
       
   127       // Since this error could be caused someone rewriting the method
       
   128       // but not knowing to update the stackmap data, we call the the
       
   129       // verifier's error method, which may not throw an exception and
       
   130       // failover to the old verifier instead.
       
   131       _verifier->class_format_error(
       
   132         "StackMapTable format error: bad type array size");
       
   133     }
       
   134   }
       
   135 
       
   136   enum {
       
   137     SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247,
       
   138     SAME_EXTENDED = 251,
       
   139     FULL = 255
       
   140   };
       
   141 
       
   142  public:
       
   143   // Constructor
       
   144   StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data,
       
   145                  int32_t code_len, TRAPS) :
       
   146                  _verifier(v), _stream(stream),
       
   147                  _code_data(code_data), _code_length(code_len) {
       
   148     methodHandle m = v->method();
       
   149     if (m->has_stackmap_table()) {
       
   150       _cp = constantPoolHandle(THREAD, m->constants());
       
   151       _frame_count = _stream->get_u2(CHECK);
       
   152     } else {
       
   153       // There's no stackmap table present. Frame count and size are 0.
       
   154       _frame_count = 0;
       
   155     }
       
   156   }
       
   157 
       
   158   inline int32_t get_frame_count() const                { return _frame_count; }
       
   159   StackMapFrame* next(StackMapFrame* pre_frame, bool first,
       
   160                       u2 max_locals, u2 max_stack, TRAPS);
       
   161 
       
   162   void check_end(TRAPS) {
       
   163     if (!_stream->at_end()) {
       
   164       StackMapStream::stackmap_format_error("wrong attribute size", CHECK);
       
   165     }
       
   166   }
       
   167 };
       
   168 
       
   169 #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP