1 /*
2 * Copyright (c) 1998, 2019, 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 void ExceptionHandlerTable::add_entry(HandlerTableEntry entry) {
31 _nesting.check();
32 if (_length >= _size) {
33 // not enough space => grow the table (amortized growth, double its size)
34 guarantee(_size > 0, "no space allocated => cannot grow the table since it is part of nmethod");
35 int new_size = _size * 2;
36 _table = REALLOC_RESOURCE_ARRAY(HandlerTableEntry, _table, _size, new_size);
37 _size = new_size;
38 }
39 assert(_length < _size, "sanity check");
40 _table[_length++] = entry;
41 }
42
43
44 HandlerTableEntry* ExceptionHandlerTable::subtable_for(int catch_pco) const {
45 int i = 0;
46 while (i < _length) {
47 HandlerTableEntry* t = _table + i;
48 if (t->pco() == catch_pco) {
49 // found subtable matching the catch_pco
50 return t;
51 } else {
52 // advance to next subtable
53 i += t->len() + 1; // +1 for header
54 }
55 }
56 return NULL;
57 }
58
59
60 ExceptionHandlerTable::ExceptionHandlerTable(int initial_size) {
61 guarantee(initial_size > 0, "initial size must be > 0");
62 _table = NEW_RESOURCE_ARRAY(HandlerTableEntry, initial_size);
63 _length = 0;
64 _size = initial_size;
65 }
66
67
68 ExceptionHandlerTable::ExceptionHandlerTable(const CompiledMethod* cm) {
69 _table = (HandlerTableEntry*)cm->handler_table_begin();
70 _length = cm->handler_table_size() / sizeof(HandlerTableEntry);
71 _size = 0; // no space allocated by ExeptionHandlerTable!
72 }
73
74
75 void ExceptionHandlerTable::add_subtable(
76 int catch_pco,
77 GrowableArray<intptr_t>* handler_bcis,
78 GrowableArray<intptr_t>* scope_depths_from_top_scope,
79 GrowableArray<intptr_t>* handler_pcos
80 ) {
81 assert(subtable_for(catch_pco) == NULL, "catch handlers for this catch_pco added twice");
82 assert(handler_bcis->length() == handler_pcos->length(), "bci & pc table have different length");
83 assert(scope_depths_from_top_scope == NULL || handler_bcis->length() == scope_depths_from_top_scope->length(), "bci & scope_depths table have different length");
84 if (handler_bcis->length() > 0) {
85 // add subtable header
86 add_entry(HandlerTableEntry(handler_bcis->length(), catch_pco, 0));
87 // add individual entries
88 for (int i = 0; i < handler_bcis->length(); i++) {
89 intptr_t scope_depth = 0;
90 if (scope_depths_from_top_scope != NULL) {
91 scope_depth = scope_depths_from_top_scope->at(i);
92 }
93 add_entry(HandlerTableEntry(handler_bcis->at(i), handler_pcos->at(i), scope_depth));
94 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->pco() == handler_pcos->at(i), "entry not added correctly (1)");
95 assert(entry_for(catch_pco, handler_bcis->at(i), scope_depth)->scope_depth() == scope_depth, "entry not added correctly (2)");
96 }
97 }
98 }
99
100
101 void ExceptionHandlerTable::copy_to(CompiledMethod* cm) {
102 assert(size_in_bytes() == cm->handler_table_size(), "size of space allocated in compiled method incorrect");
103 copy_bytes_to(cm->handler_table_begin());
104 }
105
106 void ExceptionHandlerTable::copy_bytes_to(address addr) {
107 memmove(addr, _table, size_in_bytes());
108 }
109
110 HandlerTableEntry* ExceptionHandlerTable::entry_for(int catch_pco, int handler_bci, int scope_depth) const {
111 HandlerTableEntry* t = subtable_for(catch_pco);
112 if (t != NULL) {
113 int l = t->len();
114 while (l-- > 0) {
115 t++;
116 if (t->bci() == handler_bci && t->scope_depth() == scope_depth) return t;
117 }
118 }
119 return NULL;
120 }
121
122
123 void ExceptionHandlerTable::print_subtable(HandlerTableEntry* t) const {
124 int l = t->len();
125 tty->print_cr("catch_pco = %d (%d entries)", t->pco(), l);
126 while (l-- > 0) {
127 t++;
128 tty->print_cr(" bci %d at scope depth %d -> pco %d", t->bci(), t->scope_depth(), t->pco());
129 }
130 }
131
132
133 void ExceptionHandlerTable::print() const {
134 tty->print_cr("ExceptionHandlerTable (size = %d bytes)", size_in_bytes());
135 int i = 0;
136 while (i < _length) {
137 HandlerTableEntry* t = _table + i;
138 print_subtable(t);
139 // advance to next subtable
140 i += t->len() + 1; // +1 for header
141 }
142 }
143
144 void ExceptionHandlerTable::print_subtable_for(int catch_pco) const {
145 HandlerTableEntry* subtable = subtable_for(catch_pco);
146
147 if( subtable != NULL ) { print_subtable( subtable ); }
148 }
149
150 // ----------------------------------------------------------------------------
151 // Implicit null exception tables. Maps an exception PC offset to a
152 // continuation PC offset. During construction it's a variable sized
153 // array with a max size and current length. When stored inside an
154 // nmethod a zero length table takes no space. This is detected by
155 // nul_chk_table_size() == 0. Otherwise the table has a length word
156 // followed by pairs of <excp-offset, const-offset>.
157 void ImplicitExceptionTable::set_size( uint size ) {
158 _size = size;
159 _data = NEW_RESOURCE_ARRAY(implicit_null_entry, (size*2));
160 _len = 0;
161 }
162
163 void ImplicitExceptionTable::append( uint exec_off, uint cont_off ) {
164 assert( (sizeof(implicit_null_entry) >= 4) || (exec_off < 65535), "" );
165 assert( (sizeof(implicit_null_entry) >= 4) || (cont_off < 65535), "" );
166 uint l = len();
167 if (l == _size) {
168 uint old_size_in_elements = _size*2;
169 if (_size == 0) _size = 4;
170 _size *= 2;
171 uint new_size_in_elements = _size*2;
172 _data = REALLOC_RESOURCE_ARRAY(uint, _data, old_size_in_elements, new_size_in_elements);
173 }
174 *(adr(l) ) = exec_off;
175 *(adr(l)+1) = cont_off;
176 _len = l+1;
177 };
178
179 uint ImplicitExceptionTable::at( uint exec_off ) const {
180 uint l = len();
181 for( uint i=0; i<l; i++ )
182 if( *adr(i) == exec_off )
183 return *(adr(i)+1);
184 return 0; // Failed to find any execption offset
185 }
186
187 void ImplicitExceptionTable::print(address base) const {
188 const uint n = len();
189 if (n > 0) {
190 const uint items_per_line = 3;
191 uint i;
192 tty->print_cr("ImplicitExceptionTable (size = %d entries, %d bytes):", n, size_in_bytes());
193 tty->print("{");
194 for (i = 0; i < n; i++) {
195 if (i%items_per_line == 0) {
196 tty->cr();
197 tty->fill_to(3);
198 }
199 tty->print("< " INTPTR_FORMAT ", " INTPTR_FORMAT " > ", p2i(base + *adr(i)), p2i(base + *(adr(i)+1)));
200 }
201 tty->bol();
202 tty->print_cr("}");
203 } else {
204 tty->print_cr("ImplicitExceptionTable is empty");
205 }
206 }
207
208 ImplicitExceptionTable::ImplicitExceptionTable(const nmethod* nm) {
209 if (nm->nul_chk_table_size() == 0) {
210 _len = 0;
211 _data = NULL;
212 } else {
213 // the first word is the length if non-zero, so read it out and
214 // skip to the next word to get the table.
215 _data = (implicit_null_entry*)nm->nul_chk_table_begin();
216 _len = _data[0];
217 _data++;
218 }
219 _size = len();
220 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
221 }
222
223 void ImplicitExceptionTable::copy_to( nmethod* nm ) {
224 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect");
225 if (len() != 0) {
226 implicit_null_entry* nmdata = (implicit_null_entry*)nm->nul_chk_table_begin();
227 // store the length in the first uint
228 nmdata[0] = _len;
229 nmdata++;
230 // copy the table after the length
231 memmove( nmdata, _data, 2 * len() * sizeof(implicit_null_entry));
232 } else {
233 // zero length table takes zero bytes
234 assert(size_in_bytes() == 0, "bad size");
235 assert(nm->nul_chk_table_size() == 0, "bad size");
236 }
237 }
238
239 void ImplicitExceptionTable::verify(nmethod *nm) const {
240 for (uint i = 0; i < len(); i++) {
241 if ((*adr(i) > (unsigned int)nm->insts_size()) ||
242 (*(adr(i)+1) > (unsigned int)nm->insts_size()))
243 fatal("Invalid offset in ImplicitExceptionTable at " PTR_FORMAT, p2i(_data));
244 }
245 }