diff -r 000000000000 -r a61af66fc99e src/share/vm/classfile/stackMapTable.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/classfile/stackMapTable.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,161 @@ +/* + * Copyright 2003-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +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, 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, 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; + + // Debugging + void print() const PRODUCT_RETURN; +}; + +class StackMapStream : StackObj { + private: + typeArrayHandle _data; + int _index; + public: + StackMapStream(typeArrayHandle 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->byte_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((u1*)_data->byte_at_addr(_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); + } + } +};