1 /*
2 * Copyright (c) 1998, 2010, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_exceptionHandlerTable.cpp.incl"
27
28 void ExceptionHandlerTable::add_entry(HandlerTableEntry entry) {
29 _nesting.check();
30 if (_length >= _size) {
31 // not enough space => grow the table (amortized growth, double its size)
32 guarantee(_size > 0, "no space allocated => cannot grow the table since it is part of nmethod");
33 int new_size = _size * 2;
34 _table = REALLOC_RESOURCE_ARRAY(HandlerTableEntry, _table, _size, new_size);
35 _size = new_size;
36 }
37 assert(_length < _size, "sanity check");
38 _table[_length++] = entry;
39 }
40
41
42 HandlerTableEntry* ExceptionHandlerTable::subtable_for(int catch_pco) const {
43 int i = 0;
44 while (i < _length) {
45 HandlerTableEntry* t = _table + i;
46 if (t->pco() == catch_pco) {
47 // found subtable matching the catch_pco
48 return t;
49 } else {
50 // advance to next subtable
51 i += t->len() + 1; // +1 for header
52 }
53 }
54 return NULL;
55 }
56
57
58 ExceptionHandlerTable::ExceptionHandlerTable(int initial_size) {
59 guarantee(initial_size > 0, "initial size must be > 0");
60 _table = NEW_RESOURCE_ARRAY(HandlerTableEntry, initial_size);
61 _length = 0;
62 _size = initial_size;
63 }
64
65
66 ExceptionHandlerTable::ExceptionHandlerTable(const nmethod* nm) {
67 _table = (HandlerTableEntry*)nm->handler_table_begin();
68 _length = nm->handler_table_size() / sizeof(HandlerTableEntry);
69 _size = 0; // no space allocated by ExeptionHandlerTable!
70 }
71
72
73 void ExceptionHandlerTable::add_subtable(
74 int catch_pco,
75 GrowableArray<intptr_t>* handler_bcis,
76 GrowableArray<intptr_t>* scope_depths_from_top_scope,
77 GrowableArray<intptr_t>* handler_pcos
78 ) {
79 assert(subtable_for(catch_pco) == NULL, "catch handlers for this catch_pco added twice");
80 assert(handler_bcis->length() == handler_pcos->length(), "bci & pc table have different length");
81 assert(scope_depths_from_top_scope == NULL || handler_bcis->length() == scope_depths_from_top_scope->length(), "bci & scope_depths table have different length");
82 if (handler_bcis->length() > 0) {
83 // add subtable header
84 add_entry(HandlerTableEntry(handler_bcis->length(), catch_pco, 0));
85 // add individual entries
86 for (int i = 0; i < handler_bcis->length(); i++) {
87 intptr_t scope_depth = 0;
88 if (scope_depths_from_top_scope != NULL) {
89 scope_depth = scope_depths_from_top_scope->at(i);
90 }
91 add_entry(HandlerTableEntry(handler_bcis->at(i), handler_pcos->at(i), scope_depth));
92 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->pco() == handler_pcos->at(i), "entry not added correctly (1)");
93 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->scope_depth() == scope_depth, "entry not added correctly (2)");
94 }
95 }
96 }
97
98
99 void ExceptionHandlerTable::copy_to(nmethod* nm) {
100 assert(size_in_bytes() == nm->handler_table_size(), "size of space allocated in nmethod incorrect");
101 memmove(nm->handler_table_begin(), _table, size_in_bytes());
102 }
103
104
105 HandlerTableEntry* ExceptionHandlerTable::entry_for(int catch_pco, int handler_bci, int scope_depth) const {
106 HandlerTableEntry* t = subtable_for(catch_pco);
107 if (t != NULL) {
108 int l = t->len();
109 while (l-- > 0) {
110 t++;
111 if (t->bci() == handler_bci && t->scope_depth() == scope_depth) return t;
112 }
113 }
114 return NULL;
115 }
116
117
118 void ExceptionHandlerTable::print_subtable(HandlerTableEntry* t) const {
119 int l = t->len();
120 tty->print_cr("catch_pco = %d (%d entries)", t->pco(), l);
121 while (l-- > 0) {
122 t++;
123 tty->print_cr(" bci %d at scope depth %d -> pco %d", t->bci(), t->scope_depth(), t->pco());
124 }
125 }
126
127
128 void ExceptionHandlerTable::print() const {
129 tty->print_cr("ExceptionHandlerTable (size = %d bytes)", size_in_bytes());
130 int i = 0;
131 while (i < _length) {
132 HandlerTableEntry* t = _table + i;
133 print_subtable(t);
134 // advance to next subtable
135 i += t->len() + 1; // +1 for header
136 }
137 }
138
139 void ExceptionHandlerTable::print_subtable_for(int catch_pco) const {
140 HandlerTableEntry* subtable = subtable_for(catch_pco);
141
142 if( subtable != NULL ) { print_subtable( subtable ); }
143 }
144
145 // ----------------------------------------------------------------------------
146 // Implicit null exception tables. Maps an exception PC offset to a
147 // continuation PC offset. During construction it's a variable sized
148 // array with a max size and current length. When stored inside an
149 // nmethod a zero length table takes no space. This is detected by
150 // nul_chk_table_size() == 0. Otherwise the table has a length word
151 // followed by pairs of <excp-offset, const-offset>.
152 void ImplicitExceptionTable::set_size( uint size ) {
153 _size = size;
154 _data = NEW_RESOURCE_ARRAY(implicit_null_entry, (size*2));
155 _len = 0;
156 }
157
158 void ImplicitExceptionTable::append( uint exec_off, uint cont_off ) {
159 assert( (sizeof(implicit_null_entry) >= 4) || (exec_off < 65535), "" );
160 assert( (sizeof(implicit_null_entry) >= 4) || (cont_off < 65535), "" );
161 uint l = len();
162 if (l == _size) {
163 uint old_size_in_elements = _size*2;
164 if (_size == 0) _size = 4;
165 _size *= 2;
166 uint new_size_in_elements = _size*2;
167 _data = REALLOC_RESOURCE_ARRAY(uint, _data, old_size_in_elements, new_size_in_elements);
168 }
169 *(adr(l) ) = exec_off;
170 *(adr(l)+1) = cont_off;
171 _len = l+1;
172 };
173
174 uint ImplicitExceptionTable::at( uint exec_off ) const {
175 uint l = len();
176 for( uint i=0; i<l; i++ )
177 if( *adr(i) == exec_off )
178 return *(adr(i)+1);
179 return 0; // Failed to find any execption offset
180 }
181
182 void ImplicitExceptionTable::print(address base) const {
183 tty->print("{");
184 for( uint i=0; i<len(); i++ )
185 tty->print("< "INTPTR_FORMAT", "INTPTR_FORMAT" > ",base + *adr(i), base + *(adr(i)+1));
186 tty->print_cr("}");
187 }
188
189 ImplicitExceptionTable::ImplicitExceptionTable(const nmethod* nm) {
190 if (nm->nul_chk_table_size() == 0) {
191 _len = 0;
192 _data = NULL;
193 } else {
194 // the first word is the length if non-zero, so read it out and
195 // skip to the next word to get the table.
196 _data = (implicit_null_entry*)nm->nul_chk_table_begin();
197 _len = _data[0];
198 _data++;
199 }
200 _size = len();
201 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
202 }
203
204 void ImplicitExceptionTable::copy_to( nmethod* nm ) {
205 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
206 if (len() != 0) {
207 implicit_null_entry* nmdata = (implicit_null_entry*)nm->nul_chk_table_begin();
208 // store the length in the first uint
209 nmdata[0] = _len;
210 nmdata++;
211 // copy the table after the length
212 memmove( nmdata, _data, 2 * len() * sizeof(implicit_null_entry));
213 } else {
214 // zero length table takes zero bytes
215 assert(size_in_bytes() == 0, "bad size");
216 assert(nm->nul_chk_table_size() == 0, "bad size");
217 }
218 }
219
220 void ImplicitExceptionTable::verify(nmethod *nm) const {
221 for (uint i = 0; i < len(); i++) {
222 if ((*adr(i) > (unsigned int)nm->insts_size()) ||
223 (*(adr(i)+1) > (unsigned int)nm->insts_size()))
224 fatal(err_msg("Invalid offset in ImplicitExceptionTable at " PTR_FORMAT, _data));
225 }
226 }