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 }