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 }