| /* |
| * Copyright (c) 1998, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP |
| #define SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP |
| |
| #include "memory/allocation.hpp" |
| #include "oops/method.hpp" |
| #include "utilities/align.hpp" |
| |
| // A HandlerTableEntry describes an individual entry of a subtable |
| // of ExceptionHandlerTable. An entry consists of a pair(bci, pco), |
| // where bci is the exception handler bci, and pco is the pc offset |
| // relative to the nmethod code start for the compiled exception |
| // handler corresponding to the (interpreted) exception handler |
| // starting at bci. |
| // |
| // The first HandlerTableEntry of each subtable holds the length |
| // and catch_pco for the subtable (the length is the number of |
| // subtable entries w/o header). |
| |
| class HandlerTableEntry { |
| private: |
| int _bci; |
| int _pco; |
| int _scope_depth; |
| |
| public: |
| HandlerTableEntry(int bci, int pco, int scope_depth) { |
| assert( 0 <= pco, "pco must be positive"); |
| assert( 0 <= scope_depth, "scope_depth must be positive"); |
| _bci = bci; |
| _pco = pco; |
| _scope_depth = scope_depth; |
| } |
| |
| int len() const { return _bci; } // for entry at subtable begin |
| int bci() const { return _bci; } |
| int pco() const { return _pco; } |
| int scope_depth() const { return _scope_depth; } |
| }; |
| |
| |
| // An ExceptionHandlerTable is an abstraction over a list of subtables |
| // of exception handlers for CatchNodes. Each subtable has a one-entry |
| // header holding length and catch_pco of the subtable, followed |
| // by 'length' entries for each exception handler that can be reached |
| // from the corresponding CatchNode. The catch_pco is the pc offset of |
| // the CatchNode in the corresponding nmethod. Empty subtables are dis- |
| // carded. |
| // |
| // Structure of the table: |
| // |
| // table = { subtable }. |
| // subtable = header entry { entry }. |
| // header = a pair (number of subtable entries, catch pc offset, [unused]) |
| // entry = a pair (handler bci, handler pc offset, scope depth) |
| // |
| // An ExceptionHandlerTable can be created from scratch, in which case |
| // it is possible to add subtables. It can also be created from an |
| // nmethod (for lookup purposes) in which case the table cannot be |
| // modified. |
| |
| class nmethod; |
| class ExceptionHandlerTable VALUE_OBJ_CLASS_SPEC { |
| private: |
| HandlerTableEntry* _table; // the table |
| int _length; // the current length of the table |
| int _size; // the number of allocated entries |
| ReallocMark _nesting; // assertion check for reallocations |
| |
| public: |
| // add the entry & grow the table if needed |
| void add_entry(HandlerTableEntry entry); |
| HandlerTableEntry* subtable_for(int catch_pco) const; |
| |
| // (compile-time) construction within compiler |
| ExceptionHandlerTable(int initial_size = 8); |
| |
| // (run-time) construction from nmethod |
| ExceptionHandlerTable(const CompiledMethod* nm); |
| |
| // (compile-time) add entries |
| void add_subtable( |
| int catch_pco, // the pc offset for the CatchNode |
| GrowableArray<intptr_t>* handler_bcis, // the exception handler entry point bcis |
| GrowableArray<intptr_t>* scope_depths_from_top_scope, |
| // if representing exception handlers in multiple |
| // inlined scopes, indicates which scope relative to |
| // the youngest/innermost one in which we are performing |
| // the lookup; zero (or null GrowableArray) indicates |
| // innermost scope |
| GrowableArray<intptr_t>* handler_pcos // pc offsets for the compiled handlers |
| ); |
| |
| // nmethod support |
| int size_in_bytes() const { return align_up(_length * (int)sizeof(HandlerTableEntry), oopSize); } |
| void copy_to(CompiledMethod* nm); |
| void copy_bytes_to(address addr); |
| |
| // lookup |
| HandlerTableEntry* entry_for(int catch_pco, int handler_bci, int scope_depth) const; |
| |
| // debugging |
| void print_subtable(HandlerTableEntry* t) const; |
| void print() const; |
| void print_subtable_for(int catch_pco) const; |
| }; |
| |
| |
| // ---------------------------------------------------------------------------- |
| // Implicit null exception tables. Maps an exception PC offset to a |
| // continuation PC offset. During construction it's a variable sized |
| // array with a max size and current length. When stored inside an |
| // nmethod a zero length table takes no space. This is detected by |
| // nul_chk_table_size() == 0. Otherwise the table has a length word |
| // followed by pairs of <excp-offset, const-offset>. |
| |
| // Use 32-bit representation for offsets |
| typedef uint implicit_null_entry; |
| |
| class ImplicitExceptionTable VALUE_OBJ_CLASS_SPEC { |
| uint _size; |
| uint _len; |
| implicit_null_entry *_data; |
| implicit_null_entry *adr( uint idx ) const { return &_data[2*idx]; } |
| ReallocMark _nesting; // assertion check for reallocations |
| public: |
| ImplicitExceptionTable( ) : _data(0), _size(0), _len(0) { } |
| // (run-time) construction from nmethod |
| ImplicitExceptionTable( const nmethod *nm ); |
| |
| void set_size( uint size ); |
| void append( uint exec_off, uint cont_off ); |
| uint at( uint exec_off ) const; |
| |
| uint len() const { return _len; } |
| int size_in_bytes() const { return len() == 0 ? 0 : ((2 * len() + 1) * sizeof(implicit_null_entry)); } |
| |
| void copy_to(nmethod* nm); |
| void print(address base) const; |
| void verify(nmethod *nm) const; |
| }; |
| |
| #endif // SHARE_VM_CODE_EXCEPTIONHANDLERTABLE_HPP |