1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/code/exceptionHandlerTable.hpp Sat Dec 01 00:00:00 2007 +0000
1.3 @@ -0,0 +1,156 @@
1.4 +/*
1.5 + * Copyright 1998-2005 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 +// A HandlerTableEntry describes an individual entry of a subtable
1.29 +// of ExceptionHandlerTable. An entry consists of a pair(bci, pco),
1.30 +// where bci is the exception handler bci, and pco is the pc offset
1.31 +// relative to the nmethod code start for the compiled exception
1.32 +// handler corresponding to the (interpreted) exception handler
1.33 +// starting at bci.
1.34 +//
1.35 +// The first HandlerTableEntry of each subtable holds the length
1.36 +// and catch_pco for the subtable (the length is the number of
1.37 +// subtable entries w/o header).
1.38 +
1.39 +class HandlerTableEntry {
1.40 + private:
1.41 + int _bci;
1.42 + int _pco;
1.43 + int _scope_depth;
1.44 +
1.45 + public:
1.46 + HandlerTableEntry(int bci, int pco, int scope_depth) {
1.47 + assert( 0 <= pco, "pco must be positive");
1.48 + assert( 0 <= scope_depth, "scope_depth must be positive");
1.49 + _bci = bci;
1.50 + _pco = pco;
1.51 + _scope_depth = scope_depth;
1.52 + }
1.53 +
1.54 + int len() const { return _bci; } // for entry at subtable begin
1.55 + int bci() const { return _bci; }
1.56 + int pco() const { return _pco; }
1.57 + int scope_depth() const { return _scope_depth; }
1.58 +};
1.59 +
1.60 +
1.61 +// An ExceptionHandlerTable is an abstraction over a list of subtables
1.62 +// of exception handlers for CatchNodes. Each subtable has a one-entry
1.63 +// header holding length and catch_pco of the subtable, followed
1.64 +// by 'length' entries for each exception handler that can be reached
1.65 +// from the corresponding CatchNode. The catch_pco is the pc offset of
1.66 +// the CatchNode in the corresponding nmethod. Empty subtables are dis-
1.67 +// carded.
1.68 +//
1.69 +// Structure of the table:
1.70 +//
1.71 +// table = { subtable }.
1.72 +// subtable = header entry { entry }.
1.73 +// header = a pair (number of subtable entries, catch pc offset, [unused])
1.74 +// entry = a pair (handler bci, handler pc offset, scope depth)
1.75 +//
1.76 +// An ExceptionHandlerTable can be created from scratch, in which case
1.77 +// it is possible to add subtables. It can also be created from an
1.78 +// nmethod (for lookup purposes) in which case the table cannot be
1.79 +// modified.
1.80 +
1.81 +class nmethod;
1.82 +class ExceptionHandlerTable VALUE_OBJ_CLASS_SPEC {
1.83 + private:
1.84 + HandlerTableEntry* _table; // the table
1.85 + int _length; // the current length of the table
1.86 + int _size; // the number of allocated entries
1.87 + ReallocMark _nesting; // assertion check for reallocations
1.88 +
1.89 + // add the entry & grow the table if needed
1.90 + void add_entry(HandlerTableEntry entry);
1.91 + HandlerTableEntry* subtable_for(int catch_pco) const;
1.92 +
1.93 + public:
1.94 + // (compile-time) construction within compiler
1.95 + ExceptionHandlerTable(int initial_size = 8);
1.96 +
1.97 + // (run-time) construction from nmethod
1.98 + ExceptionHandlerTable(const nmethod* nm);
1.99 +
1.100 + // (compile-time) add entries
1.101 + void add_subtable(
1.102 + int catch_pco, // the pc offset for the CatchNode
1.103 + GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis
1.104 + GrowableArray<intptr_t>* scope_depths_from_top_scope,
1.105 + // if representing exception handlers in multiple
1.106 + // inlined scopes, indicates which scope relative to
1.107 + // the youngest/innermost one in which we are performing
1.108 + // the lookup; zero (or null GrowableArray) indicates
1.109 + // innermost scope
1.110 + GrowableArray<intptr_t>* handler_pcos // pc offsets for the compiled handlers
1.111 + );
1.112 +
1.113 + // nmethod support
1.114 + int size_in_bytes() const { return round_to(_length * sizeof(HandlerTableEntry), oopSize); }
1.115 + void copy_to(nmethod* nm);
1.116 +
1.117 + // lookup
1.118 + HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const;
1.119 +
1.120 + // debugging
1.121 + void print_subtable(HandlerTableEntry* t) const;
1.122 + void print() const;
1.123 + void print_subtable_for(int catch_pco) const;
1.124 +};
1.125 +
1.126 +
1.127 +// ----------------------------------------------------------------------------
1.128 +// Implicit null exception tables. Maps an exception PC offset to a
1.129 +// continuation PC offset. During construction it's a variable sized
1.130 +// array with a max size and current length. When stored inside an
1.131 +// nmethod a zero length table takes no space. This is detected by
1.132 +// nul_chk_table_size() == 0. Otherwise the table has a length word
1.133 +// followed by pairs of <excp-offset, const-offset>.
1.134 +
1.135 +// Use 32-bit representation for offsets
1.136 +typedef uint implicit_null_entry;
1.137 +
1.138 +class ImplicitExceptionTable VALUE_OBJ_CLASS_SPEC {
1.139 + uint _size;
1.140 + uint _len;
1.141 + implicit_null_entry *_data;
1.142 + implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; }
1.143 + ReallocMark _nesting; // assertion check for reallocations
1.144 +public:
1.145 + ImplicitExceptionTable( ) : _data(0), _size(0), _len(0) { }
1.146 + // (run-time) construction from nmethod
1.147 + ImplicitExceptionTable( const nmethod *nm );
1.148 +
1.149 + void set_size( uint size );
1.150 + void append( uint exec_off, uint cont_off );
1.151 + uint at( uint exec_off ) const;
1.152 +
1.153 + uint len() const { return _len; }
1.154 + int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * sizeof(implicit_null_entry)); }
1.155 +
1.156 + void copy_to(nmethod* nm);
1.157 + void print(address base) const;
1.158 + void verify(nmethod *nm) const;
1.159 +};
