1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/ci/ciStreams.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,369 @@
1.4 +/*
1.5 + * Copyright 1999-2005 Sun Microsystems, Inc. All Rights Reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
1.23 + * CA 95054 USA or visit www.sun.com if you need additional information or
1.24 + * have any questions.
1.25 + *
1.26 + */
1.27 +
1.28 +// ciBytecodeStream
1.29 +//
1.30 +// The class is used to iterate over the bytecodes of a method.
1.31 +// It hides the details of constant pool structure/access by
1.32 +// providing accessors for constant pool items. It returns only pure
1.33 +// Java bytecodes; VM-internal _fast bytecodes are translated back to
1.34 +// their original form during iteration.
1.35 +class ciBytecodeStream : StackObj {
1.36 +private:
1.37 + // Handling for the weird bytecodes
1.38 + Bytecodes::Code wide(); // Handle wide bytecode
1.39 + Bytecodes::Code table(Bytecodes::Code); // Handle complicated inline table
1.40 +
1.41 + static Bytecodes::Code check_java(Bytecodes::Code c) {
1.42 + assert(Bytecodes::is_java_code(c), "should not return _fast bytecodes");
1.43 + return c;
1.44 + }
1.45 +
1.46 + ciMethod* _method; // the method
1.47 + ciInstanceKlass* _holder;
1.48 + address _bc_start; // Start of current bytecode for table
1.49 + address _was_wide; // Address past last wide bytecode
1.50 + jint* _table_base; // Aligned start of last table or switch
1.51 +
1.52 + address _start; // Start of bytecodes
1.53 + address _end; // Past end of bytecodes
1.54 + address _pc; // Current PC
1.55 + Bytecodes::Code _bc; // Current bytecode
1.56 +
1.57 + void reset( address base, unsigned int size ) {
1.58 + _bc_start =_was_wide = 0;
1.59 + _start = _pc = base; _end = base + size; }
1.60 +
1.61 +public:
1.62 + // End-Of-Bytecodes
1.63 + static Bytecodes::Code EOBC() {
1.64 + return Bytecodes::_illegal;
1.65 + }
1.66 +
1.67 + ciBytecodeStream(ciMethod* m) {
1.68 + reset_to_method(m);
1.69 + }
1.70 +
1.71 + ciBytecodeStream() {
1.72 + reset_to_method(NULL);
1.73 + }
1.74 +
1.75 + ciMethod* method() const { return _method; }
1.76 +
1.77 + void reset_to_method(ciMethod* m) {
1.78 + _method = m;
1.79 + if (m == NULL) {
1.80 + _holder = NULL;
1.81 + reset(NULL, 0);
1.82 + } else {
1.83 + _holder = m->holder();
1.84 + reset(m->code(), m->code_size());
1.85 + }
1.86 + }
1.87 +
1.88 + void reset_to_bci( int bci );
1.89 +
1.90 + // Force the iterator to report a certain bci.
1.91 + void force_bci(int bci);
1.92 +
1.93 + void set_max_bci( int max ) {
1.94 + _end = _start + max;
1.95 + }
1.96 +
1.97 + address cur_bcp() { return _bc_start; } // Returns bcp to current instruction
1.98 + int next_bci() const { return _pc -_start; }
1.99 + int cur_bci() const { return _bc_start - _start; }
1.100 +
1.101 + Bytecodes::Code cur_bc() const{ return check_java(_bc); }
1.102 + Bytecodes::Code next_bc() { return Bytecodes::java_code((Bytecodes::Code)* _pc); }
1.103 +
1.104 + // Return current ByteCode and increment PC to next bytecode, skipping all
1.105 + // intermediate constants. Returns EOBC at end.
1.106 + // Expected usage:
1.107 + // while( (bc = iter.next()) != EOBC() ) { ... }
1.108 + Bytecodes::Code next() {
1.109 + _bc_start = _pc; // Capture start of bc
1.110 + if( _pc >= _end ) return EOBC(); // End-Of-Bytecodes
1.111 +
1.112 + // Fetch Java bytecode
1.113 + // All rewritten bytecodes maintain the size of original bytecode.
1.114 + _bc = Bytecodes::java_code((Bytecodes::Code)*_pc);
1.115 + int csize = Bytecodes::length_for(_bc); // Expected size
1.116 +
1.117 + if( _bc == Bytecodes::_wide ) {
1.118 + _bc=wide(); // Handle wide bytecode
1.119 + } else if( csize == 0 ) {
1.120 + _bc=table(_bc); // Handle inline tables
1.121 + } else {
1.122 + _pc += csize; // Bump PC past bytecode
1.123 + }
1.124 + return check_java(_bc);
1.125 + }
1.126 +
1.127 + bool is_wide() { return ( _pc == _was_wide ); }
1.128 +
1.129 + // Get a byte index following this bytecode.
1.130 + // If prefixed with a wide bytecode, get a wide index.
1.131 + int get_index() const {
1.132 + return (_pc == _was_wide) // was widened?
1.133 + ? Bytes::get_Java_u2(_bc_start+2) // yes, return wide index
1.134 + : _bc_start[1]; // no, return narrow index
1.135 + }
1.136 +
1.137 + // Set a byte index following this bytecode.
1.138 + // If prefixed with a wide bytecode, get a wide index.
1.139 + void put_index(int idx) {
1.140 + if (_pc == _was_wide) // was widened?
1.141 + Bytes::put_Java_u2(_bc_start+2,idx); // yes, set wide index
1.142 + else
1.143 + _bc_start[1]=idx; // no, set narrow index
1.144 + }
1.145 +
1.146 + // Get 2-byte index (getfield/putstatic/etc)
1.147 + int get_index_big() const { return Bytes::get_Java_u2(_bc_start+1); }
1.148 +
1.149 + // Get dimensions byte (multinewarray)
1.150 + int get_dimensions() const { return *(unsigned char*)(_pc-1); }
1.151 +
1.152 + // Get unsigned index fast
1.153 + int get_index_fast() const { return Bytes::get_native_u2(_pc-2); }
1.154 +
1.155 + // Sign-extended index byte/short, no widening
1.156 + int get_byte() const { return (int8_t)(_pc[-1]); }
1.157 + int get_short() const { return (int16_t)Bytes::get_Java_u2(_pc-2); }
1.158 + int get_long() const { return (int32_t)Bytes::get_Java_u4(_pc-4); }
1.159 +
1.160 + // Get a byte signed constant for "iinc". Invalid for other bytecodes.
1.161 + // If prefixed with a wide bytecode, get a wide constant
1.162 + int get_iinc_con() const {return (_pc==_was_wide) ? get_short() :get_byte();}
1.163 +
1.164 + // 2-byte branch offset from current pc
1.165 + int get_dest( ) const {
1.166 + assert( Bytecodes::length_at(_bc_start) == sizeof(jshort)+1, "get_dest called with bad bytecode" );
1.167 + return _bc_start-_start + (short)Bytes::get_Java_u2(_pc-2);
1.168 + }
1.169 +
1.170 + // 2-byte branch offset from next pc
1.171 + int next_get_dest( ) const {
1.172 + address next_bc_start = _pc;
1.173 + assert( _pc < _end, "" );
1.174 + Bytecodes::Code next_bc = (Bytecodes::Code)*_pc;
1.175 + assert( next_bc != Bytecodes::_wide, "");
1.176 + int next_csize = Bytecodes::length_for(next_bc);
1.177 + assert( next_csize != 0, "" );
1.178 + assert( next_bc <= Bytecodes::_jsr_w, "");
1.179 + address next_pc = _pc + next_csize;
1.180 + assert( Bytecodes::length_at(next_bc_start) == sizeof(jshort)+1, "next_get_dest called with bad bytecode" );
1.181 + return next_bc_start-_start + (short)Bytes::get_Java_u2(next_pc-2);
1.182 + }
1.183 +
1.184 + // 4-byte branch offset from current pc
1.185 + int get_far_dest( ) const {
1.186 + assert( Bytecodes::length_at(_bc_start) == sizeof(jint)+1, "dest4 called with bad bytecode" );
1.187 + return _bc_start-_start + (int)Bytes::get_Java_u4(_pc-4);
1.188 + }
1.189 +
1.190 + // For a lookup or switch table, return target destination
1.191 + int get_int_table( int index ) const {
1.192 + return Bytes::get_Java_u4((address)&_table_base[index]); }
1.193 +
1.194 + // For tableswitch - get length of offset part
1.195 + int get_tableswitch_length() { return get_int_table(2)-get_int_table(1)+1; }
1.196 +
1.197 + int get_dest_table( int index ) const {
1.198 + return cur_bci() + get_int_table(index); }
1.199 +
1.200 + // --- Constant pool access ---
1.201 + int get_constant_index() const;
1.202 + int get_field_index();
1.203 + int get_method_index();
1.204 +
1.205 + // If this bytecode is a new, newarray, multianewarray, instanceof,
1.206 + // or checkcast, get the referenced klass.
1.207 + ciKlass* get_klass(bool& will_link);
1.208 + int get_klass_index() const;
1.209 +
1.210 + // If this bytecode is one of the ldc variants, get the referenced
1.211 + // constant
1.212 + ciConstant get_constant();
1.213 + // True if the ldc variant points to an unresolved string
1.214 + bool is_unresolved_string() const;
1.215 + // True if the ldc variant points to an unresolved klass
1.216 + bool is_unresolved_klass() const;
1.217 +
1.218 + // If this bytecode is one of get_field, get_static, put_field,
1.219 + // or put_static, get the referenced field.
1.220 + ciField* get_field(bool& will_link);
1.221 +
1.222 + ciInstanceKlass* get_declared_field_holder();
1.223 + int get_field_holder_index();
1.224 + int get_field_signature_index();
1.225 +
1.226 + // If this is a method invocation bytecode, get the invoked method.
1.227 + ciMethod* get_method(bool& will_link);
1.228 + ciKlass* get_declared_method_holder();
1.229 + int get_method_holder_index();
1.230 + int get_method_signature_index();
1.231 +};
1.232 +
1.233 +
1.234 +// ciSignatureStream
1.235 +//
1.236 +// The class is used to iterate over the elements of a method signature.
1.237 +class ciSignatureStream : public StackObj {
1.238 +private:
1.239 + ciSignature* _sig;
1.240 + int _pos;
1.241 +public:
1.242 + ciSignatureStream(ciSignature* signature) {
1.243 + _sig = signature;
1.244 + _pos = 0;
1.245 + }
1.246 +
1.247 + bool at_return_type() { return _pos == _sig->count(); }
1.248 +
1.249 + bool is_done() { return _pos > _sig->count(); }
1.250 +
1.251 + void next() {
1.252 + if (_pos <= _sig->count()) {
1.253 + _pos++;
1.254 + }
1.255 + }
1.256 +
1.257 + ciType* type() {
1.258 + if (at_return_type()) {
1.259 + return _sig->return_type();
1.260 + } else {
1.261 + return _sig->type_at(_pos);
1.262 + }
1.263 + }
1.264 +};
1.265 +
1.266 +
1.267 +// ciExceptionHandlerStream
1.268 +//
1.269 +// The class is used to iterate over the exception handlers of
1.270 +// a method.
1.271 +class ciExceptionHandlerStream : public StackObj {
1.272 +private:
1.273 + // The method whose handlers we are traversing
1.274 + ciMethod* _method;
1.275 +
1.276 + // Our current position in the list of handlers
1.277 + int _pos;
1.278 + int _end;
1.279 +
1.280 + ciInstanceKlass* _exception_klass;
1.281 + int _bci;
1.282 + bool _is_exact;
1.283 +
1.284 +public:
1.285 + ciExceptionHandlerStream(ciMethod* method) {
1.286 + _method = method;
1.287 +
1.288 + // Force loading of method code and handlers.
1.289 + _method->code();
1.290 +
1.291 + _pos = 0;
1.292 + _end = _method->_handler_count;
1.293 + _exception_klass = NULL;
1.294 + _bci = -1;
1.295 + _is_exact = false;
1.296 + }
1.297 +
1.298 + ciExceptionHandlerStream(ciMethod* method, int bci,
1.299 + ciInstanceKlass* exception_klass = NULL,
1.300 + bool is_exact = false) {
1.301 + _method = method;
1.302 +
1.303 + // Force loading of method code and handlers.
1.304 + _method->code();
1.305 +
1.306 + _pos = -1;
1.307 + _end = _method->_handler_count + 1; // include the rethrow handler
1.308 + _exception_klass = (exception_klass != NULL && exception_klass->is_loaded()
1.309 + ? exception_klass
1.310 + : NULL);
1.311 + _bci = bci;
1.312 + assert(_bci >= 0, "bci out of range");
1.313 + _is_exact = is_exact;
1.314 + next();
1.315 + }
1.316 +
1.317 + // These methods are currently implemented in an odd way.
1.318 + // Count the number of handlers the iterator has ever produced
1.319 + // or will ever produce. Do not include the final rethrow handler.
1.320 + // That is, a trivial exception handler stream will have a count
1.321 + // of zero and produce just the rethrow handler.
1.322 + int count();
1.323 +
1.324 + // Count the number of handlers this stream will produce from now on.
1.325 + // Include the current handler, and the final rethrow handler.
1.326 + // The remaining count will be zero iff is_done() is true,
1.327 + int count_remaining();
1.328 +
1.329 + bool is_done() {
1.330 + return (_pos >= _end);
1.331 + }
1.332 +
1.333 + void next() {
1.334 + _pos++;
1.335 + if (_bci != -1) {
1.336 + // We are not iterating over all handlers...
1.337 + while (!is_done()) {
1.338 + ciExceptionHandler* handler = _method->_exception_handlers[_pos];
1.339 + if (handler->is_in_range(_bci)) {
1.340 + if (handler->is_catch_all()) {
1.341 + // Found final active catch block.
1.342 + _end = _pos+1;
1.343 + return;
1.344 + } else if (_exception_klass == NULL || !handler->catch_klass()->is_loaded()) {
1.345 + // We cannot do any type analysis here. Must conservatively assume
1.346 + // catch block is reachable.
1.347 + return;
1.348 + } else if (_exception_klass->is_subtype_of(handler->catch_klass())) {
1.349 + // This catch clause will definitely catch the exception.
1.350 + // Final candidate.
1.351 + _end = _pos+1;
1.352 + return;
1.353 + } else if (!_is_exact &&
1.354 + handler->catch_klass()->is_subtype_of(_exception_klass)) {
1.355 + // This catch block may be reachable.
1.356 + return;
1.357 + }
1.358 + }
1.359 +
1.360 + // The catch block was not pertinent. Go on.
1.361 + _pos++;
1.362 + }
1.363 + } else {
1.364 + // This is an iteration over all handlers.
1.365 + return;
1.366 + }
1.367 + }
1.368 +
1.369 + ciExceptionHandler* handler() {
1.370 + return _method->_exception_handlers[_pos];
1.371 + }
1.372 +};
