| /* |
| * Copyright 1999-2005 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. |
| * |
| */ |
| |
| // ciBytecodeStream |
| // |
| // The class is used to iterate over the bytecodes of a method. |
| // It hides the details of constant pool structure/access by |
| // providing accessors for constant pool items. It returns only pure |
| // Java bytecodes; VM-internal _fast bytecodes are translated back to |
| // their original form during iteration. |
| class ciBytecodeStream : StackObj { |
| private: |
| // Handling for the weird bytecodes |
| Bytecodes::Code wide(); // Handle wide bytecode |
| Bytecodes::Code table(Bytecodes::Code); // Handle complicated inline table |
| |
| static Bytecodes::Code check_java(Bytecodes::Code c) { |
| assert(Bytecodes::is_java_code(c), "should not return _fast bytecodes"); |
| return c; |
| } |
| |
| ciMethod* _method; // the method |
| ciInstanceKlass* _holder; |
| address _bc_start; // Start of current bytecode for table |
| address _was_wide; // Address past last wide bytecode |
| jint* _table_base; // Aligned start of last table or switch |
| |
| address _start; // Start of bytecodes |
| address _end; // Past end of bytecodes |
| address _pc; // Current PC |
| Bytecodes::Code _bc; // Current bytecode |
| |
| void reset( address base, unsigned int size ) { |
| _bc_start =_was_wide = 0; |
| _start = _pc = base; _end = base + size; } |
| |
| public: |
| // End-Of-Bytecodes |
| static Bytecodes::Code EOBC() { |
| return Bytecodes::_illegal; |
| } |
| |
| ciBytecodeStream(ciMethod* m) { |
| reset_to_method(m); |
| } |
| |
| ciBytecodeStream() { |
| reset_to_method(NULL); |
| } |
| |
| ciMethod* method() const { return _method; } |
| |
| void reset_to_method(ciMethod* m) { |
| _method = m; |
| if (m == NULL) { |
| _holder = NULL; |
| reset(NULL, 0); |
| } else { |
| _holder = m->holder(); |
| reset(m->code(), m->code_size()); |
| } |
| } |
| |
| void reset_to_bci( int bci ); |
| |
| // Force the iterator to report a certain bci. |
| void force_bci(int bci); |
| |
| void set_max_bci( int max ) { |
| _end = _start + max; |
| } |
| |
| address cur_bcp() const { return _bc_start; } // Returns bcp to current instruction |
| int next_bci() const { return _pc -_start; } |
| int cur_bci() const { return _bc_start - _start; } |
| int instruction_size() const { return _pc - _bc_start; } |
| |
| Bytecodes::Code cur_bc() const{ return check_java(_bc); } |
| Bytecodes::Code next_bc() { return Bytecodes::java_code((Bytecodes::Code)* _pc); } |
| |
| // Return current ByteCode and increment PC to next bytecode, skipping all |
| // intermediate constants. Returns EOBC at end. |
| // Expected usage: |
| // while( (bc = iter.next()) != EOBC() ) { ... } |
| Bytecodes::Code next() { |
| _bc_start = _pc; // Capture start of bc |
| if( _pc >= _end ) return EOBC(); // End-Of-Bytecodes |
| |
| // Fetch Java bytecode |
| // All rewritten bytecodes maintain the size of original bytecode. |
| _bc = Bytecodes::java_code((Bytecodes::Code)*_pc); |
| int csize = Bytecodes::length_for(_bc); // Expected size |
| |
| if( _bc == Bytecodes::_wide ) { |
| _bc=wide(); // Handle wide bytecode |
| } else if( csize == 0 ) { |
| _bc=table(_bc); // Handle inline tables |
| } else { |
| _pc += csize; // Bump PC past bytecode |
| } |
| return check_java(_bc); |
| } |
| |
| bool is_wide() const { return ( _pc == _was_wide ); } |
| |
| // Get a byte index following this bytecode. |
| // If prefixed with a wide bytecode, get a wide index. |
| int get_index() const { |
| assert_index_size(is_wide() ? 2 : 1); |
| return (_pc == _was_wide) // was widened? |
| ? Bytes::get_Java_u2(_bc_start+2) // yes, return wide index |
| : _bc_start[1]; // no, return narrow index |
| } |
| |
| // Get 2-byte index (getfield/putstatic/etc) |
| int get_index_big() const { |
| assert_index_size(2); |
| return Bytes::get_Java_u2(_bc_start+1); |
| } |
| |
| // Get 2-byte index (or 4-byte, for invokedynamic) |
| int get_index_int() const { |
| return has_giant_index() ? get_index_giant() : get_index_big(); |
| } |
| |
| // Get 4-byte index, for invokedynamic. |
| int get_index_giant() const { |
| assert_index_size(4); |
| return Bytes::get_native_u4(_bc_start+1); |
| } |
| |
| bool has_giant_index() const { return (cur_bc() == Bytecodes::_invokedynamic); } |
| |
| // Get dimensions byte (multinewarray) |
| int get_dimensions() const { return *(unsigned char*)(_pc-1); } |
| |
| // Sign-extended index byte/short, no widening |
| int get_byte() const { return (int8_t)(_pc[-1]); } |
| int get_short() const { return (int16_t)Bytes::get_Java_u2(_pc-2); } |
| int get_long() const { return (int32_t)Bytes::get_Java_u4(_pc-4); } |
| |
| // Get a byte signed constant for "iinc". Invalid for other bytecodes. |
| // If prefixed with a wide bytecode, get a wide constant |
| int get_iinc_con() const {return (_pc==_was_wide) ? get_short() :get_byte();} |
| |
| // 2-byte branch offset from current pc |
| int get_dest( ) const { |
| assert( Bytecodes::length_at(_bc_start) == sizeof(jshort)+1, "get_dest called with bad bytecode" ); |
| return _bc_start-_start + (short)Bytes::get_Java_u2(_pc-2); |
| } |
| |
| // 2-byte branch offset from next pc |
| int next_get_dest( ) const { |
| address next_bc_start = _pc; |
| assert( _pc < _end, "" ); |
| Bytecodes::Code next_bc = (Bytecodes::Code)*_pc; |
| assert( next_bc != Bytecodes::_wide, ""); |
| int next_csize = Bytecodes::length_for(next_bc); |
| assert( next_csize != 0, "" ); |
| assert( next_bc <= Bytecodes::_jsr_w, ""); |
| address next_pc = _pc + next_csize; |
| assert( Bytecodes::length_at(next_bc_start) == sizeof(jshort)+1, "next_get_dest called with bad bytecode" ); |
| return next_bc_start-_start + (short)Bytes::get_Java_u2(next_pc-2); |
| } |
| |
| // 4-byte branch offset from current pc |
| int get_far_dest( ) const { |
| assert( Bytecodes::length_at(_bc_start) == sizeof(jint)+1, "dest4 called with bad bytecode" ); |
| return _bc_start-_start + (int)Bytes::get_Java_u4(_pc-4); |
| } |
| |
| // For a lookup or switch table, return target destination |
| int get_int_table( int index ) const { |
| return Bytes::get_Java_u4((address)&_table_base[index]); } |
| |
| // For tableswitch - get length of offset part |
| int get_tableswitch_length() { return get_int_table(2)-get_int_table(1)+1; } |
| |
| int get_dest_table( int index ) const { |
| return cur_bci() + get_int_table(index); } |
| |
| // --- Constant pool access --- |
| int get_constant_index() const; |
| int get_field_index(); |
| int get_method_index(); |
| |
| // If this bytecode is a new, newarray, multianewarray, instanceof, |
| // or checkcast, get the referenced klass. |
| ciKlass* get_klass(bool& will_link); |
| int get_klass_index() const; |
| |
| // If this bytecode is one of the ldc variants, get the referenced |
| // constant |
| ciConstant get_constant(); |
| // True if the ldc variant points to an unresolved string |
| bool is_unresolved_string() const; |
| // True if the ldc variant points to an unresolved klass |
| bool is_unresolved_klass() const; |
| |
| // If this bytecode is one of get_field, get_static, put_field, |
| // or put_static, get the referenced field. |
| ciField* get_field(bool& will_link); |
| |
| ciInstanceKlass* get_declared_field_holder(); |
| int get_field_holder_index(); |
| int get_field_signature_index(); |
| |
| // If this is a method invocation bytecode, get the invoked method. |
| ciMethod* get_method(bool& will_link); |
| ciKlass* get_declared_method_holder(); |
| int get_method_holder_index(); |
| int get_method_signature_index(); |
| |
| private: |
| void assert_index_size(int required_size) const { |
| #ifdef ASSERT |
| int isize = instruction_size() - (is_wide() ? 1 : 0) - 1; |
| if (isize == 2 && cur_bc() == Bytecodes::_iinc) |
| isize = 1; |
| else if (isize <= 2) |
| ; // no change |
| else if (has_giant_index()) |
| isize = 4; |
| else |
| isize = 2; |
| assert(isize = required_size, "wrong index size"); |
| #endif |
| } |
| }; |
| |
| |
| // ciSignatureStream |
| // |
| // The class is used to iterate over the elements of a method signature. |
| class ciSignatureStream : public StackObj { |
| private: |
| ciSignature* _sig; |
| int _pos; |
| public: |
| ciSignatureStream(ciSignature* signature) { |
| _sig = signature; |
| _pos = 0; |
| } |
| |
| bool at_return_type() { return _pos == _sig->count(); } |
| |
| bool is_done() { return _pos > _sig->count(); } |
| |
| void next() { |
| if (_pos <= _sig->count()) { |
| _pos++; |
| } |
| } |
| |
| ciType* type() { |
| if (at_return_type()) { |
| return _sig->return_type(); |
| } else { |
| return _sig->type_at(_pos); |
| } |
| } |
| }; |
| |
| |
| // ciExceptionHandlerStream |
| // |
| // The class is used to iterate over the exception handlers of |
| // a method. |
| class ciExceptionHandlerStream : public StackObj { |
| private: |
| // The method whose handlers we are traversing |
| ciMethod* _method; |
| |
| // Our current position in the list of handlers |
| int _pos; |
| int _end; |
| |
| ciInstanceKlass* _exception_klass; |
| int _bci; |
| bool _is_exact; |
| |
| public: |
| ciExceptionHandlerStream(ciMethod* method) { |
| _method = method; |
| |
| // Force loading of method code and handlers. |
| _method->code(); |
| |
| _pos = 0; |
| _end = _method->_handler_count; |
| _exception_klass = NULL; |
| _bci = -1; |
| _is_exact = false; |
| } |
| |
| ciExceptionHandlerStream(ciMethod* method, int bci, |
| ciInstanceKlass* exception_klass = NULL, |
| bool is_exact = false) { |
| _method = method; |
| |
| // Force loading of method code and handlers. |
| _method->code(); |
| |
| _pos = -1; |
| _end = _method->_handler_count + 1; // include the rethrow handler |
| _exception_klass = (exception_klass != NULL && exception_klass->is_loaded() |
| ? exception_klass |
| : NULL); |
| _bci = bci; |
| assert(_bci >= 0, "bci out of range"); |
| _is_exact = is_exact; |
| next(); |
| } |
| |
| // These methods are currently implemented in an odd way. |
| // Count the number of handlers the iterator has ever produced |
| // or will ever produce. Do not include the final rethrow handler. |
| // That is, a trivial exception handler stream will have a count |
| // of zero and produce just the rethrow handler. |
| int count(); |
| |
| // Count the number of handlers this stream will produce from now on. |
| // Include the current handler, and the final rethrow handler. |
| // The remaining count will be zero iff is_done() is true, |
| int count_remaining(); |
| |
| bool is_done() { |
| return (_pos >= _end); |
| } |
| |
| void next() { |
| _pos++; |
| if (_bci != -1) { |
| // We are not iterating over all handlers... |
| while (!is_done()) { |
| ciExceptionHandler* handler = _method->_exception_handlers[_pos]; |
| if (handler->is_in_range(_bci)) { |
| if (handler->is_catch_all()) { |
| // Found final active catch block. |
| _end = _pos+1; |
| return; |
| } else if (_exception_klass == NULL || !handler->catch_klass()->is_loaded()) { |
| // We cannot do any type analysis here. Must conservatively assume |
| // catch block is reachable. |
| return; |
| } else if (_exception_klass->is_subtype_of(handler->catch_klass())) { |
| // This catch clause will definitely catch the exception. |
| // Final candidate. |
| _end = _pos+1; |
| return; |
| } else if (!_is_exact && |
| handler->catch_klass()->is_subtype_of(_exception_klass)) { |
| // This catch block may be reachable. |
| return; |
| } |
| } |
| |
| // The catch block was not pertinent. Go on. |
| _pos++; |
| } |
| } else { |
| // This is an iteration over all handlers. |
| return; |
| } |
| } |
| |
| ciExceptionHandler* handler() { |
| return _method->_exception_handlers[_pos]; |
| } |
| }; |