jdk8-mips64-public/hotspot: src/share/vm/ci/ciStreams.hpp@a61af66fc99e (annotated)

src/share/vm/ci/ciStreams.hpp@a61af66fc99e (annotated)

src/share/vm/ci/ciStreams.hpp

Sat, 01 Dec 2007 00:00:00 +0000

author: duke
date: Sat, 01 Dec 2007 00:00:00 +0000
changeset 435: a61af66fc99e
child 1161: be93aad57795
permissions: -rw-r--r--

Initial load

 /*
  * 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];
   }
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/ci/ciStreams.hpp@a61af66fc99e (annotated)

src/share/vm/ci/ciStreams.hpp