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 }