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 copy_bytes_to(nm->handler_table_begin()); 106 } 107 108 void ExceptionHandlerTable::copy_bytes_to(address addr) { 109 memmove(addr, _table, size_in_bytes()); 110 } 111 112 HandlerTableEntry* ExceptionHandlerTable::entry_for(int catch_pco, int handler_bci, int scope_depth) const { 113 HandlerTableEntry* t = subtable_for(catch_pco); 114 if (t != NULL) { 115 int l = t->len(); 116 while (l-- > 0) { 117 t++; 118 if (t->bci() == handler_bci && t->scope_depth() == scope_depth) return t; 119 } 120 } 121 return NULL; 122 } 123 124 125 void ExceptionHandlerTable::print_subtable(HandlerTableEntry* t) const { 126 int l = t->len(); 127 tty->print_cr("catch_pco = %d (%d entries)", t->pco(), l); 128 while (l-- > 0) { 129 t++; 130 tty->print_cr(" bci %d at scope depth %d -> pco %d", t->bci(), t->scope_depth(), t->pco()); 131 } 132 } 133 134 135 void ExceptionHandlerTable::print() const { 136 tty->print_cr("ExceptionHandlerTable (size = %d bytes)", size_in_bytes()); 137 int i = 0; 138 while (i < _length) { 139 HandlerTableEntry* t = _table + i; 140 print_subtable(t); 141 // advance to next subtable 142 i += t->len() + 1; // +1 for header 143 } 144 } 145 146 void ExceptionHandlerTable::print_subtable_for(int catch_pco) const { 147 HandlerTableEntry* subtable = subtable_for(catch_pco); 148 149 if( subtable != NULL ) { print_subtable( subtable ); } 150 } 151 152 // ---------------------------------------------------------------------------- 153 // Implicit null exception tables. Maps an exception PC offset to a 154 // continuation PC offset. During construction it's a variable sized 155 // array with a max size and current length. When stored inside an 156 // nmethod a zero length table takes no space. This is detected by 157 // nul_chk_table_size() == 0. Otherwise the table has a length word 158 // followed by pairs of <excp-offset, const-offset>. 159 void ImplicitExceptionTable::set_size( uint size ) { 160 _size = size; 161 _data = NEW_RESOURCE_ARRAY(implicit_null_entry, (size*2)); 162 _len = 0; 163 } 164 165 void ImplicitExceptionTable::append( uint exec_off, uint cont_off ) { 166 assert( (sizeof(implicit_null_entry) >= 4) || (exec_off < 65535), "" ); 167 assert( (sizeof(implicit_null_entry) >= 4) || (cont_off < 65535), "" ); 168 uint l = len(); 169 if (l == _size) { 170 uint old_size_in_elements = _size*2; 171 if (_size == 0) _size = 4; 172 _size *= 2; 173 uint new_size_in_elements = _size*2; 174 _data = REALLOC_RESOURCE_ARRAY(uint, _data, old_size_in_elements, new_size_in_elements); 175 } 176 *(adr(l) ) = exec_off; 177 *(adr(l)+1) = cont_off; 178 _len = l+1; 179 }; 180 181 uint ImplicitExceptionTable::at( uint exec_off ) const { 182 uint l = len(); 183 for( uint i=0; i<l; i++ ) 184 if( *adr(i) == exec_off ) 185 return *(adr(i)+1); 186 return 0; // Failed to find any execption offset 187 } 188 189 void ImplicitExceptionTable::print(address base) const { 190 tty->print("{"); 191 for( uint i=0; i<len(); i++ ) 192 tty->print("< " INTPTR_FORMAT ", " INTPTR_FORMAT " > ",base + *adr(i), base + *(adr(i)+1)); 193 tty->print_cr("}"); 194 } 195 196 ImplicitExceptionTable::ImplicitExceptionTable(const nmethod* nm) { 197 if (nm->nul_chk_table_size() == 0) { 198 _len = 0; 199 _data = NULL; 200 } else { 201 // the first word is the length if non-zero, so read it out and 202 // skip to the next word to get the table. 203 _data = (implicit_null_entry*)nm->nul_chk_table_begin(); 204 _len = _data[0]; 205 _data++; 206 } 207 _size = len(); 208 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect"); 209 } 210 211 void ImplicitExceptionTable::copy_to( nmethod* nm ) { 212 assert(size_in_bytes() <= nm->nul_chk_table_size(), "size of space allocated in nmethod incorrect"); 213 if (len() != 0) { 214 implicit_null_entry* nmdata = (implicit_null_entry*)nm->nul_chk_table_begin(); 215 // store the length in the first uint 216 nmdata[0] = _len; 217 nmdata++; 218 // copy the table after the length 219 memmove( nmdata, _data, 2 * len() * sizeof(implicit_null_entry)); 220 } else { 221 // zero length table takes zero bytes 222 assert(size_in_bytes() == 0, "bad size"); 223 assert(nm->nul_chk_table_size() == 0, "bad size"); 224 } 225 } 226 227 void ImplicitExceptionTable::verify(nmethod *nm) const { 228 for (uint i = 0; i < len(); i++) { 229 if ((*adr(i) > (unsigned int)nm->insts_size()) || 230 (*(adr(i)+1) > (unsigned int)nm->insts_size())) 231 fatal(err_msg("Invalid offset in ImplicitExceptionTable at " PTR_FORMAT, _data)); 232 } 233 }