/* * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. * */ #ifndef SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP #define SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP #include "classfile/stackMapFrame.hpp" #include "classfile/verifier.hpp" #include "memory/allocation.hpp" #include "oops/constantPool.hpp" #include "oops/method.hpp" #include "utilities/globalDefinitions.hpp" #ifdef TARGET_ARCH_x86 # include "bytes_x86.hpp" #endif #ifdef TARGET_ARCH_sparc # include "bytes_sparc.hpp" #endif #ifdef TARGET_ARCH_zero # include "bytes_zero.hpp" #endif #ifdef TARGET_ARCH_arm # include "bytes_arm.hpp" #endif #ifdef TARGET_ARCH_ppc # include "bytes_ppc.hpp" #endif class StackMapReader; // StackMapTable class is the StackMap table used by type checker class StackMapTable : public StackObj { private: // Logically, the _frame_count (as well as many fields in the StackFrame) // should be a u2, but if we defined the variable as that type it will // be difficult to detect/recover from overflow or underflow conditions. // Widening the type and making it signed will help detect these. int32_t _code_length; int32_t _frame_count; // Stackmap frame count StackMapFrame** _frame_array; public: StackMapTable(StackMapReader* reader, StackMapFrame* init_frame, u2 max_locals, u2 max_stack, char* code_data, int code_len, TRAPS); inline int32_t get_frame_count() const { return _frame_count; } inline int get_offset(int index) const { return _frame_array[index]->offset(); } // Match and/or update current_frame to the frame in stackmap table with // specified offset. Return true if the two frames match. bool match_stackmap( StackMapFrame* current_frame, int32_t offset, bool match, bool update, bool handler, ErrorContext* ctx, TRAPS) const; // Match and/or update current_frame to the frame in stackmap table with // specified offset and frame index. Return true if the two frames match. bool match_stackmap( StackMapFrame* current_frame, int32_t offset, int32_t frame_index, bool match, bool update, bool handler, ErrorContext* ctx, TRAPS) const; // Check jump instructions. Make sure there are no uninitialized // instances on backward branch. void check_jump_target(StackMapFrame* frame, int32_t target, TRAPS) const; // The following methods are only used inside this class. // Returns the frame array index where the frame with offset is stored. int get_index_from_offset(int32_t offset) const; // Make sure that there's no uninitialized object exist on backward branch. void check_new_object( const StackMapFrame* frame, int32_t target, TRAPS) const; void print_on(outputStream* str) const; }; class StackMapStream : StackObj { private: Array* _data; int _index; public: StackMapStream(Array* ah) : _data(ah), _index(0) { } u1 get_u1(TRAPS) { if (_data == NULL || _index >= _data->length()) { stackmap_format_error("access beyond the end of attribute", CHECK_0); } return _data->at(_index++); } u2 get_u2(TRAPS) { if (_data == NULL || _index >= _data->length() - 1) { stackmap_format_error("access beyond the end of attribute", CHECK_0); } u2 res = Bytes::get_Java_u2(_data->adr_at(_index)); _index += 2; return res; } bool at_end() { return (_data == NULL) || (_index == _data->length()); } static void stackmap_format_error(const char* msg, TRAPS); }; class StackMapReader : StackObj { private: // information about the class and method constantPoolHandle _cp; ClassVerifier* _verifier; StackMapStream* _stream; char* _code_data; int32_t _code_length; // information get from the attribute int32_t _frame_count; // frame count int32_t chop(VerificationType* locals, int32_t length, int32_t chops); VerificationType parse_verification_type(u1* flags, TRAPS); void check_verification_type_array_size( int32_t size, int32_t max_size, TRAPS) { if (size < 0 || size > max_size) { // Since this error could be caused someone rewriting the method // but not knowing to update the stackmap data, we call the the // verifier's error method, which may not throw an exception and // failover to the old verifier instead. _verifier->class_format_error( "StackMapTable format error: bad type array size"); } } enum { SAME_LOCALS_1_STACK_ITEM_EXTENDED = 247, SAME_EXTENDED = 251, FULL = 255 }; public: // Constructor StackMapReader(ClassVerifier* v, StackMapStream* stream, char* code_data, int32_t code_len, TRAPS) : _verifier(v), _stream(stream), _code_data(code_data), _code_length(code_len) { methodHandle m = v->method(); if (m->has_stackmap_table()) { _cp = constantPoolHandle(THREAD, m->constants()); _frame_count = _stream->get_u2(CHECK); } else { // There's no stackmap table present. Frame count and size are 0. _frame_count = 0; } } inline int32_t get_frame_count() const { return _frame_count; } StackMapFrame* next(StackMapFrame* pre_frame, bool first, u2 max_locals, u2 max_stack, TRAPS); void check_end(TRAPS) { if (!_stream->at_end()) { StackMapStream::stackmap_format_error("wrong attribute size", CHECK); } } }; #endif // SHARE_VM_CLASSFILE_STACKMAPTABLE_HPP