1 /*

     2  * Copyright 1999-2005 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 #include "incls/_precompiled.incl"

    26 #include "incls/_ciStreams.cpp.incl"

    27 

    28 // ciExceptionHandlerStream

    29 //

    30 // Walk over some selected set of a methods exception handlers.

    31 

    32 // ------------------------------------------------------------------

    33 // ciExceptionHandlerStream::count

    34 //

    35 // How many exception handlers are there in this stream?

    36 //

    37 // Implementation note: Compiler2 needs this functionality, so I had

    38 int ciExceptionHandlerStream::count() {

    39   int save_pos = _pos;

    40   int save_end = _end;

    41 

    42   int count = 0;

    43 

    44   _pos = -1;

    45   _end = _method->_handler_count;

    46 

    47 

    48   next();

    49   while (!is_done()) {

    50     count++;

    51     next();

    52   }

    53 

    54   _pos = save_pos;

    55   _end = save_end;

    56 

    57   return count;

    58 }

    59 

    60 int ciExceptionHandlerStream::count_remaining() {

    61   int save_pos = _pos;

    62   int save_end = _end;

    63 

    64   int count = 0;

    65 

    66   while (!is_done()) {

    67     count++;

    68     next();

    69   }

    70 

    71   _pos = save_pos;

    72   _end = save_end;

    73 

    74   return count;

    75 }

    76 

    77 // ciBytecodeStream

    78 //

    79 // The class is used to iterate over the bytecodes of a method.

    80 // It hides the details of constant pool structure/access by

    81 // providing accessors for constant pool items.

    82 

    83 // ------------------------------------------------------------------

    84 // ciBytecodeStream::wide

    85 //

    86 // Special handling for the wide bytcode

    87 Bytecodes::Code ciBytecodeStream::wide()

    88 {

    89   // Get following bytecode; do not return wide

    90   Bytecodes::Code bc = (Bytecodes::Code)_pc[1];

    91   _pc += 2;                     // Skip both bytecodes

    92   _pc += 2;                     // Skip index always

    93   if( bc == Bytecodes::_iinc )

    94     _pc += 2;                   // Skip optional constant

    95   _was_wide = _pc;              // Flag last wide bytecode found

    96   return bc;

    97 }

    98 

    99 // ------------------------------------------------------------------

   100 // ciBytecodeStream::table

   101 //

   102 // Special handling for switch ops

   103 Bytecodes::Code ciBytecodeStream::table( Bytecodes::Code bc ) {

   104   switch( bc ) {                // Check for special bytecode handling

   105 

   106   case Bytecodes::_lookupswitch:

   107     _pc++;                      // Skip wide bytecode

   108     _pc += (_start-_pc)&3;      // Word align

   109     _table_base = (jint*)_pc;   // Capture for later usage

   110                                 // table_base[0] is default far_dest

   111     // Table has 2 lead elements (default, length), then pairs of u4 values.

   112     // So load table length, and compute address at end of table

   113     _pc = (address)&_table_base[2+ 2*Bytes::get_Java_u4((address)&_table_base[1])];

   114     break;

   115 

   116   case Bytecodes::_tableswitch: {

   117     _pc++;                      // Skip wide bytecode

   118     _pc += (_start-_pc)&3;      // Word align

   119     _table_base = (jint*)_pc;   // Capture for later usage

   120                                 // table_base[0] is default far_dest

   121     int lo = Bytes::get_Java_u4((address)&_table_base[1]);// Low bound

   122     int hi = Bytes::get_Java_u4((address)&_table_base[2]);// High bound

   123     int len = hi - lo + 1;      // Dense table size

   124     _pc = (address)&_table_base[3+len]; // Skip past table

   125     break;

   126   }

   127 

   128   default:

   129     fatal("unhandled bytecode");

   130   }

   131   return bc;

   132 }

   133 

   134 // ------------------------------------------------------------------

   135 // ciBytecodeStream::reset_to_bci

   136 void ciBytecodeStream::reset_to_bci( int bci ) {

   137   _bc_start=_was_wide=0;

   138   _pc = _start+bci;

   139 }

   140 

   141 // ------------------------------------------------------------------

   142 // ciBytecodeStream::force_bci

   143 void ciBytecodeStream::force_bci(int bci) {

   144   if (bci < 0) {

   145     reset_to_bci(0);

   146     _bc_start = _start + bci;

   147     _bc = EOBC();

   148   } else {

   149     reset_to_bci(bci);

   150     next();

   151   }

   152 }

   153 

   154 

   155 // ------------------------------------------------------------------

   156 // Constant pool access

   157 // ------------------------------------------------------------------

   158 

   159 // ------------------------------------------------------------------

   160 // ciBytecodeStream::get_klass_index

   161 //

   162 // If this bytecodes references a klass, return the index of the

   163 // referenced klass.

   164 int ciBytecodeStream::get_klass_index() const {

   165   switch(cur_bc()) {

   166   case Bytecodes::_ldc:

   167     return get_index();

   168   case Bytecodes::_ldc_w:

   169   case Bytecodes::_ldc2_w:

   170   case Bytecodes::_checkcast:

   171   case Bytecodes::_instanceof:

   172   case Bytecodes::_anewarray:

   173   case Bytecodes::_multianewarray:

   174   case Bytecodes::_new:

   175   case Bytecodes::_newarray:

   176     return get_index_big();

   177   default:

   178     ShouldNotReachHere();

   179     return 0;

   180   }

   181 }

   182 

   183 // ------------------------------------------------------------------

   184 // ciBytecodeStream::get_klass

   185 //

   186 // If this bytecode is a new, newarray, multianewarray, instanceof,

   187 // or checkcast, get the referenced klass.

   188 ciKlass* ciBytecodeStream::get_klass(bool& will_link) {

   189   return CURRENT_ENV->get_klass_by_index(_holder, get_klass_index(),

   190                                          will_link);

   191 }

   192 

   193 // ------------------------------------------------------------------

   194 // ciBytecodeStream::get_constant_index

   195 //

   196 // If this bytecode is one of the ldc variants, get the index of the

   197 // referenced constant.

   198 int ciBytecodeStream::get_constant_index() const {

   199   switch(cur_bc()) {

   200   case Bytecodes::_ldc:

   201     return get_index();

   202   case Bytecodes::_ldc_w:

   203   case Bytecodes::_ldc2_w:

   204     return get_index_big();

   205   default:

   206     ShouldNotReachHere();

   207     return 0;

   208   }

   209 }

   210 // ------------------------------------------------------------------

   211 // ciBytecodeStream::get_constant

   212 //

   213 // If this bytecode is one of the ldc variants, get the referenced

   214 // constant.

   215 ciConstant ciBytecodeStream::get_constant() {

   216   return CURRENT_ENV->get_constant_by_index(_holder, get_constant_index());

   217 }

   218 

   219 // ------------------------------------------------------------------

   220 bool ciBytecodeStream::is_unresolved_string() const {

   221   return CURRENT_ENV->is_unresolved_string(_holder, get_constant_index());

   222 }

   223 

   224 // ------------------------------------------------------------------

   225 bool ciBytecodeStream::is_unresolved_klass() const {

   226   return CURRENT_ENV->is_unresolved_klass(_holder, get_klass_index());

   227 }

   228 

   229 // ------------------------------------------------------------------

   230 // ciBytecodeStream::get_field_index

   231 //

   232 // If this is a field access bytecode, get the constant pool

   233 // index of the referenced field.

   234 int ciBytecodeStream::get_field_index() {

   235   assert(cur_bc() == Bytecodes::_getfield ||

   236          cur_bc() == Bytecodes::_putfield ||

   237          cur_bc() == Bytecodes::_getstatic ||

   238          cur_bc() == Bytecodes::_putstatic, "wrong bc");

   239   return get_index_big();

   240 }

   241 

   242 

   243 // ------------------------------------------------------------------

   244 // ciBytecodeStream::get_field

   245 //

   246 // If this bytecode is one of get_field, get_static, put_field,

   247 // or put_static, get the referenced field.

   248 ciField* ciBytecodeStream::get_field(bool& will_link) {

   249   ciField* f = CURRENT_ENV->get_field_by_index(_holder, get_field_index());

   250   will_link = f->will_link(_holder, _bc);

   251   return f;

   252 }

   253 

   254 

   255 // ------------------------------------------------------------------

   256 // ciBytecodeStream::get_declared_field_holder

   257 //

   258 // Get the declared holder of the currently referenced field.

   259 //

   260 // Usage note: the holder() of a ciField class returns the canonical

   261 // holder of the field, rather than the holder declared in the

   262 // bytecodes.

   263 //

   264 // There is no "will_link" result passed back.  The user is responsible

   265 // for checking linkability when retrieving the associated field.

   266 ciInstanceKlass* ciBytecodeStream::get_declared_field_holder() {

   267   int holder_index = get_field_holder_index();

   268   bool ignore;

   269   return CURRENT_ENV->get_klass_by_index(_holder, holder_index, ignore)

   270       ->as_instance_klass();

   271 }

   272 

   273 // ------------------------------------------------------------------

   274 // ciBytecodeStream::get_field_holder_index

   275 //

   276 // Get the constant pool index of the declared holder of the field

   277 // referenced by the current bytecode.  Used for generating

   278 // deoptimization information.

   279 int ciBytecodeStream::get_field_holder_index() {

   280   VM_ENTRY_MARK;

   281   constantPoolOop cpool = _holder->get_instanceKlass()->constants();

   282   return cpool->klass_ref_index_at(get_field_index());

   283 }

   284 

   285 // ------------------------------------------------------------------

   286 // ciBytecodeStream::get_field_signature_index

   287 //

   288 // Get the constant pool index of the signature of the field

   289 // referenced by the current bytecode.  Used for generating

   290 // deoptimization information.

   291 int ciBytecodeStream::get_field_signature_index() {

   292   VM_ENTRY_MARK;

   293   constantPoolOop cpool = _holder->get_instanceKlass()->constants();

   294   int nt_index = cpool->name_and_type_ref_index_at(get_field_index());

   295   return cpool->signature_ref_index_at(nt_index);

   296 }

   297 

   298 // ------------------------------------------------------------------

   299 // ciBytecodeStream::get_method_index

   300 //

   301 // If this is a method invocation bytecode, get the constant pool

   302 // index of the invoked method.

   303 int ciBytecodeStream::get_method_index() {

   304   switch (cur_bc()) {

   305   case Bytecodes::_invokeinterface:

   306     return Bytes::get_Java_u2(_pc-4);

   307   case Bytecodes::_invokevirtual:

   308   case Bytecodes::_invokespecial:

   309   case Bytecodes::_invokestatic:

   310     return get_index_big();

   311   default:

   312     ShouldNotReachHere();

   313     return 0;

   314   }

   315 }

   316 

   317 // ------------------------------------------------------------------

   318 // ciBytecodeStream::get_method

   319 //

   320 // If this is a method invocation bytecode, get the invoked method.

   321 ciMethod* ciBytecodeStream::get_method(bool& will_link) {

   322   ciMethod* m = CURRENT_ENV->get_method_by_index(_holder, get_method_index(),cur_bc());

   323   will_link = m->is_loaded();

   324   return m;

   325 }

   326 

   327 // ------------------------------------------------------------------

   328 // ciBytecodeStream::get_declared_method_holder

   329 //

   330 // Get the declared holder of the currently referenced method.

   331 //

   332 // Usage note: the holder() of a ciMethod class returns the canonical

   333 // holder of the method, rather than the holder declared in the

   334 // bytecodes.

   335 //

   336 // There is no "will_link" result passed back.  The user is responsible

   337 // for checking linkability when retrieving the associated method.

   338 ciKlass* ciBytecodeStream::get_declared_method_holder() {

   339   bool ignore;

   340   return CURRENT_ENV->get_klass_by_index(_holder, get_method_holder_index(), ignore);

   341 }

   342 

   343 // ------------------------------------------------------------------

   344 // ciBytecodeStream::get_method_holder_index

   345 //

   346 // Get the constant pool index of the declared holder of the method

   347 // referenced by the current bytecode.  Used for generating

   348 // deoptimization information.

   349 int ciBytecodeStream::get_method_holder_index() {

   350   VM_ENTRY_MARK;

   351   constantPoolOop cpool = _holder->get_instanceKlass()->constants();

   352   return cpool->klass_ref_index_at(get_method_index());

   353 }

   354 

   355 // ------------------------------------------------------------------

   356 // ciBytecodeStream::get_method_signature_index

   357 //

   358 // Get the constant pool index of the signature of the method

   359 // referenced by the current bytecode.  Used for generating

   360 // deoptimization information.

   361 int ciBytecodeStream::get_method_signature_index() {

   362   VM_ENTRY_MARK;

   363   constantPoolOop cpool = _holder->get_instanceKlass()->constants();

   364   int method_index = get_method_index();

   365   int name_and_type_index = cpool->name_and_type_ref_index_at(method_index);

   366   return cpool->signature_ref_index_at(name_and_type_index);

   367 }