--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/ci/ciStreams.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,369 @@
+/*
+ * 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() { return _bc_start; } // Returns bcp to current instruction
+ int next_bci() const { return _pc -_start; }
+ int cur_bci() const { return _bc_start - _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() { 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 {
+ return (_pc == _was_wide) // was widened?
+ ? Bytes::get_Java_u2(_bc_start+2) // yes, return wide index
+ : _bc_start[1]; // no, return narrow index
+ }
+
+ // Set a byte index following this bytecode.
+ // If prefixed with a wide bytecode, get a wide index.
+ void put_index(int idx) {
+ if (_pc == _was_wide) // was widened?
+ Bytes::put_Java_u2(_bc_start+2,idx); // yes, set wide index
+ else
+ _bc_start[1]=idx; // no, set narrow index
+ }
+
+ // Get 2-byte index (getfield/putstatic/etc)
+ int get_index_big() const { return Bytes::get_Java_u2(_bc_start+1); }
+
+ // Get dimensions byte (multinewarray)
+ int get_dimensions() const { return *(unsigned char*)(_pc-1); }
+
+ // Get unsigned index fast
+ int get_index_fast() const { return Bytes::get_native_u2(_pc-2); }
+
+ // 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();
+};
+
+
+// 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];
+ }
+};