--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/code/exceptionHandlerTable.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,166 @@
+/*
+ * 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