Mercurial > hg > truffle
comparison src/share/vm/code/exceptionHandlerTable.hpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | c18cbe5936b8 |
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1 /* | |
2 * Copyright 1998-2005 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 // A HandlerTableEntry describes an individual entry of a subtable | |
26 // of ExceptionHandlerTable. An entry consists of a pair(bci, pco), | |
27 // where bci is the exception handler bci, and pco is the pc offset | |
28 // relative to the nmethod code start for the compiled exception | |
29 // handler corresponding to the (interpreted) exception handler | |
30 // starting at bci. | |
31 // | |
32 // The first HandlerTableEntry of each subtable holds the length | |
33 // and catch_pco for the subtable (the length is the number of | |
34 // subtable entries w/o header). | |
35 | |
36 class HandlerTableEntry { | |
37 private: | |
38 int _bci; | |
39 int _pco; | |
40 int _scope_depth; | |
41 | |
42 public: | |
43 HandlerTableEntry(int bci, int pco, int scope_depth) { | |
44 assert( 0 <= pco, "pco must be positive"); | |
45 assert( 0 <= scope_depth, "scope_depth must be positive"); | |
46 _bci = bci; | |
47 _pco = pco; | |
48 _scope_depth = scope_depth; | |
49 } | |
50 | |
51 int len() const { return _bci; } // for entry at subtable begin | |
52 int bci() const { return _bci; } | |
53 int pco() const { return _pco; } | |
54 int scope_depth() const { return _scope_depth; } | |
55 }; | |
56 | |
57 | |
58 // An ExceptionHandlerTable is an abstraction over a list of subtables | |
59 // of exception handlers for CatchNodes. Each subtable has a one-entry | |
60 // header holding length and catch_pco of the subtable, followed | |
61 // by 'length' entries for each exception handler that can be reached | |
62 // from the corresponding CatchNode. The catch_pco is the pc offset of | |
63 // the CatchNode in the corresponding nmethod. Empty subtables are dis- | |
64 // carded. | |
65 // | |
66 // Structure of the table: | |
67 // | |
68 // table = { subtable }. | |
69 // subtable = header entry { entry }. | |
70 // header = a pair (number of subtable entries, catch pc offset, [unused]) | |
71 // entry = a pair (handler bci, handler pc offset, scope depth) | |
72 // | |
73 // An ExceptionHandlerTable can be created from scratch, in which case | |
74 // it is possible to add subtables. It can also be created from an | |
75 // nmethod (for lookup purposes) in which case the table cannot be | |
76 // modified. | |
77 | |
78 class nmethod; | |
79 class ExceptionHandlerTable VALUE_OBJ_CLASS_SPEC { | |
80 private: | |
81 HandlerTableEntry* _table; // the table | |
82 int _length; // the current length of the table | |
83 int _size; // the number of allocated entries | |
84 ReallocMark _nesting; // assertion check for reallocations | |
85 | |
86 // add the entry & grow the table if needed | |
87 void add_entry(HandlerTableEntry entry); | |
88 HandlerTableEntry* subtable_for(int catch_pco) const; | |
89 | |
90 public: | |
91 // (compile-time) construction within compiler | |
92 ExceptionHandlerTable(int initial_size = 8); | |
93 | |
94 // (run-time) construction from nmethod | |
95 ExceptionHandlerTable(const nmethod* nm); | |
96 | |
97 // (compile-time) add entries | |
98 void add_subtable( | |
99 int catch_pco, // the pc offset for the CatchNode | |
100 GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis | |
101 GrowableArray<intptr_t>* scope_depths_from_top_scope, | |
102 // if representing exception handlers in multiple | |
103 // inlined scopes, indicates which scope relative to | |
104 // the youngest/innermost one in which we are performing | |
105 // the lookup; zero (or null GrowableArray) indicates | |
106 // innermost scope | |
107 GrowableArray<intptr_t>* handler_pcos // pc offsets for the compiled handlers | |
108 ); | |
109 | |
110 // nmethod support | |
111 int size_in_bytes() const { return round_to(_length * sizeof(HandlerTableEntry), oopSize); } | |
112 void copy_to(nmethod* nm); | |
113 | |
114 // lookup | |
115 HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const; | |
116 | |
117 // debugging | |
118 void print_subtable(HandlerTableEntry* t) const; | |
119 void print() const; | |
120 void print_subtable_for(int catch_pco) const; | |
121 }; | |
122 | |
123 | |
124 // ---------------------------------------------------------------------------- | |
125 // Implicit null exception tables. Maps an exception PC offset to a | |
126 // continuation PC offset. During construction it's a variable sized | |
127 // array with a max size and current length. When stored inside an | |
128 // nmethod a zero length table takes no space. This is detected by | |
129 // nul_chk_table_size() == 0. Otherwise the table has a length word | |
130 // followed by pairs of <excp-offset, const-offset>. | |
131 | |
132 // Use 32-bit representation for offsets | |
133 typedef uint implicit_null_entry; | |
134 | |
135 class ImplicitExceptionTable VALUE_OBJ_CLASS_SPEC { | |
136 uint _size; | |
137 uint _len; | |
138 implicit_null_entry *_data; | |
139 implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; } | |
140 ReallocMark _nesting; // assertion check for reallocations | |
141 public: | |
142 ImplicitExceptionTable( ) : _data(0), _size(0), _len(0) { } | |
143 // (run-time) construction from nmethod | |
144 ImplicitExceptionTable( const nmethod *nm ); | |
145 | |
146 void set_size( uint size ); | |
147 void append( uint exec_off, uint cont_off ); | |
148 uint at( uint exec_off ) const; | |
149 | |
150 uint len() const { return _len; } | |
151 int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * sizeof(implicit_null_entry)); } | |
152 | |
153 void copy_to(nmethod* nm); | |
154 void print(address base) const; | |
155 void verify(nmethod *nm) const; | |
156 }; |