1 /*
2 * Copyright (c) 1998, 2014, 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 "precompiled.hpp"
26 #include "code/exceptionHandlerTable.hpp"
27 #include "code/nmethod.hpp"
28 #include "memory/allocation.inline.hpp"
29
30 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
31
32 void ExceptionHandlerTable::add_entry(HandlerTableEntry entry) {
33 _nesting.check();
34 if (_length >= _size) {
35 // not enough space => grow the table (amortized growth, double its size)
36 guarantee(_size > 0, "no space allocated => cannot grow the table since it is part of nmethod");
37 int new_size = _size * 2;
38 _table = REALLOC_RESOURCE_ARRAY(HandlerTableEntry, _table, _size, new_size);
39 _size = new_size;
40 }
41 assert(_length < _size, "sanity check");
42 _table[_length++] = entry;
43 }
44
45
46 HandlerTableEntry* ExceptionHandlerTable::subtable_for(int catch_pco) const {
47 int i = 0;
48 while (i < _length) {
49 HandlerTableEntry* t = _table + i;
50 if (t->pco() == catch_pco) {
51 // found subtable matching the catch_pco
52 return t;
53 } else {
54 // advance to next subtable
55 i += t->len() + 1; // +1 for header
56 }
57 }
58 return NULL;
59 }
60
61
62 ExceptionHandlerTable::ExceptionHandlerTable(int initial_size) {
63 guarantee(initial_size > 0, "initial size must be > 0");
64 _table = NEW_RESOURCE_ARRAY(HandlerTableEntry, initial_size);
65 _length = 0;
66 _size = initial_size;
67 }
68
69
70 ExceptionHandlerTable::ExceptionHandlerTable(const nmethod* nm) {
71 _table = (HandlerTableEntry*)nm->handler_table_begin();
72 _length = nm->handler_table_size() / sizeof(HandlerTableEntry);
73 _size = 0; // no space allocated by ExeptionHandlerTable!
74 }
75
76
77 void ExceptionHandlerTable::add_subtable(
78 int catch_pco,
79 GrowableArray<intptr_t>* handler_bcis,
80 GrowableArray<intptr_t>* scope_depths_from_top_scope,
81 GrowableArray<intptr_t>* handler_pcos
82 ) {
83 assert(subtable_for(catch_pco) == NULL, "catch handlers for this catch_pco added twice");
84 assert(handler_bcis->length() == handler_pcos->length(), "bci & pc table have different length");
85 assert(scope_depths_from_top_scope == NULL || handler_bcis->length() == scope_depths_from_top_scope->length(), "bci & scope_depths table have different length");
86 if (handler_bcis->length() > 0) {
87 // add subtable header
88 add_entry(HandlerTableEntry(handler_bcis->length(), catch_pco, 0));
89 // add individual entries
90 for (int i = 0; i < handler_bcis->length(); i++) {
91 intptr_t scope_depth = 0;
92 if (scope_depths_from_top_scope != NULL) {
93 scope_depth = scope_depths_from_top_scope->at(i);
94 }
95 add_entry(HandlerTableEntry(handler_bcis->at(i), handler_pcos->at(i), scope_depth));
96 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->pco() == handler_pcos->at(i), "entry not added correctly (1)");
97 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->scope_depth() == scope_depth, "entry not added correctly (2)");
98 }
99 }
100 }
101
102
103 void ExceptionHandlerTable::copy_to(nmethod* nm) {
104 assert(size_in_bytes() == nm->handler_table_size(), "size of space allocated in nmethod incorrect");
105 memmove(nm->handler_table_begin(), _table, size_in_bytes());
106 }
107
108
109 HandlerTableEntry* ExceptionHandlerTable::entry_for(int catch_pco, int handler_bci, int scope_depth) const {
110 HandlerTableEntry* t = subtable_for(catch_pco);
111 if (t != NULL) {
112 int l = t->len();
113 while (l-- > 0) {
114 t++;
115 if (t->bci() == handler_bci && t->scope_depth() == scope_depth) return t;
116 }
117 }
118 return NULL;
119 }
120
121
122 void ExceptionHandlerTable::print_subtable(HandlerTableEntry* t) const {
123 int l = t->len();
124 tty->print_cr("catch_pco = %d (%d entries)", t->pco(), l);
125 while (l-- > 0) {
126 t++;
127 tty->print_cr(" bci %d at scope depth %d -> pco %d", t->bci(), t->scope_depth(), t->pco());
128 }
129 }
130
131
132 void ExceptionHandlerTable::print() const {
133 tty->print_cr("ExceptionHandlerTable (size = %d bytes)", size_in_bytes());
134 int i = 0;
135 while (i < _length) {
136 HandlerTableEntry* t = _table + i;
137 print_subtable(t);
138 // advance to next subtable
139 i += t->len() + 1; // +1 for header
140 }
141 }
142
143 void ExceptionHandlerTable::print_subtable_for(int catch_pco) const {
144 HandlerTableEntry* subtable = subtable_for(catch_pco);
145
146 if( subtable != NULL ) { print_subtable( subtable ); }
147 }
148
149 // ----------------------------------------------------------------------------
150 // Implicit null exception tables. Maps an exception PC offset to a
151 // continuation PC offset. During construction it's a variable sized
152 // array with a max size and current length. When stored inside an
153 // nmethod a zero length table takes no space. This is detected by
154 // nul_chk_table_size() == 0. Otherwise the table has a length word
155 // followed by pairs of <excp-offset, const-offset>.
156 void ImplicitExceptionTable::set_size( uint size ) {
157 _size = size;
158 _data = NEW_RESOURCE_ARRAY(implicit_null_entry, (size*2));
159 _len = 0;
160 }
161
162 void ImplicitExceptionTable::append( uint exec_off, uint cont_off ) {
163 assert( (sizeof(implicit_null_entry) >= 4) || (exec_off < 65535), "" );
164 assert( (sizeof(implicit_null_entry) >= 4) || (cont_off < 65535), "" );
165 uint l = len();
166 if (l == _size) {
167 uint old_size_in_elements = _size*2;
168 if (_size == 0) _size = 4;
169 _size *= 2;
170 uint new_size_in_elements = _size*2;
171 _data = REALLOC_RESOURCE_ARRAY(uint, _data, old_size_in_elements, new_size_in_elements);
172 }
173 *(adr(l) ) = exec_off;
174 *(adr(l)+1) = cont_off;
175 _len = l+1;
176 };
177
178 uint ImplicitExceptionTable::at( uint exec_off ) const {
179 uint l = len();
180 for( uint i=0; i<l; i++ )
181 if( *adr(i) == exec_off )
182 return *(adr(i)+1);
183 return 0; // Failed to find any execption offset
184 }
185
186 void ImplicitExceptionTable::print(address base) const {
187 tty->print("{");
188 for( uint i=0; i<len(); i++ )
189 tty->print("< " INTPTR_FORMAT ", " INTPTR_FORMAT " > ",base + *adr(i), base + *(adr(i)+1));
190 tty->print_cr("}");
191 }
192
193 ImplicitExceptionTable::ImplicitExceptionTable(const nmethod* nm) {
194 if (nm->nul_chk_table_size() == 0) {
195 _len = 0;
196 _data = NULL;
197 } else {
198 // the first word is the length if non-zero, so read it out and
199 // skip to the next word to get the table.
200 _data = (implicit_null_entry*)nm->nul_chk_table_begin();
201 _len = _data[0];
202 _data++;
203 }
204 _size = len();
205 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
206 }
207
208 void ImplicitExceptionTable::copy_to( nmethod* nm ) {
209 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
210 if (len() != 0) {
211 implicit_null_entry* nmdata = (implicit_null_entry*)nm->nul_chk_table_begin();
212 // store the length in the first uint
213 nmdata[0] = _len;
214 nmdata++;
215 // copy the table after the length
216 memmove( nmdata, _data, 2 * len() * sizeof(implicit_null_entry));
217 } else {
218 // zero length table takes zero bytes
219 assert(size_in_bytes() == 0, "bad size");
220 assert(nm->nul_chk_table_size() == 0, "bad size");
221 }
222 }
223
224 void ImplicitExceptionTable::verify(nmethod *nm) const {
225 for (uint i = 0; i < len(); i++) {
226 if ((*adr(i) > (unsigned int)nm->insts_size()) ||
227 (*(adr(i)+1) > (unsigned int)nm->insts_size()))
228 fatal(err_msg("Invalid offset in ImplicitExceptionTable at " PTR_FORMAT, _data));
229 }
230 }