--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/interpreter/bytecodeStream.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 1997, 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_INTERPRETER_BYTECODESTREAM_HPP
+#define SHARE_VM_INTERPRETER_BYTECODESTREAM_HPP
+
+#include "interpreter/bytecode.hpp"
+#include "memory/allocation.hpp"
+#include "oops/method.hpp"
+#include "runtime/handles.inline.hpp"
+#include "utilities/bytes.hpp"
+
+// A BytecodeStream is used for fast iteration over the bytecodes
+// of a Method*.
+//
+// Usage:
+//
+// BytecodeStream s(method);
+// Bytecodes::Code c;
+// while ((c = s.next()) >= 0) {
+// ...
+// }
+
+// A RawBytecodeStream is a simple version of BytecodeStream.
+// It is used ONLY when we know the bytecodes haven't been rewritten
+// yet, such as in the rewriter or the verifier.
+
+// Here is the common base class for both RawBytecodeStream and BytecodeStream:
+class BaseBytecodeStream: StackObj {
+ protected:
+ // stream buffer
+ methodHandle _method; // read from method directly
+
+ // reading position
+ int _bci; // bci if current bytecode
+ int _next_bci; // bci of next bytecode
+ int _end_bci; // bci after the current iteration interval
+
+ // last bytecode read
+ Bytecodes::Code _raw_code;
+ bool _is_wide;
+ bool _is_raw; // false in 'cooked' BytecodeStream
+
+ // Construction
+ BaseBytecodeStream(const methodHandle& method) : _method(method) {
+ set_interval(0, _method->code_size());
+ _is_raw = false;
+ }
+
+ public:
+ // Iteration control
+ void set_interval(int beg_bci, int end_bci) {
+ // iterate over the interval [beg_bci, end_bci)
+ assert(0 <= beg_bci && beg_bci <= method()->code_size(), "illegal beg_bci");
+ assert(0 <= end_bci && end_bci <= method()->code_size(), "illegal end_bci");
+ // setup of iteration pointers
+ _bci = beg_bci;
+ _next_bci = beg_bci;
+ _end_bci = end_bci;
+ }
+ void set_start (int beg_bci) {
+ set_interval(beg_bci, _method->code_size());
+ }
+
+ bool is_raw() const { return _is_raw; }
+
+ // Stream attributes
+ const methodHandle& method() const { return _method; }
+
+ int bci() const { return _bci; }
+ int next_bci() const { return _next_bci; }
+ int end_bci() const { return _end_bci; }
+
+ Bytecodes::Code raw_code() const { return _raw_code; }
+ bool is_wide() const { return _is_wide; }
+ int instruction_size() const { return (_next_bci - _bci); }
+ bool is_last_bytecode() const { return _next_bci >= _end_bci; }
+
+ address bcp() const { return method()->code_base() + _bci; }
+ Bytecode bytecode() const { return Bytecode(_method(), bcp()); }
+
+ // State changes
+ void set_next_bci(int bci) { assert(0 <= bci && bci <= method()->code_size(), "illegal bci"); _next_bci = bci; }
+
+ // Bytecode-specific attributes
+ int dest() const { return bci() + bytecode().get_offset_s2(raw_code()); }
+ int dest_w() const { return bci() + bytecode().get_offset_s4(raw_code()); }
+
+ // One-byte indices.
+ int get_index_u1() const { assert_raw_index_size(1); return *(jubyte*)(bcp()+1); }
+
+ protected:
+ void assert_raw_index_size(int size) const NOT_DEBUG_RETURN;
+ void assert_raw_stream(bool want_raw) const NOT_DEBUG_RETURN;
+};
+
+class RawBytecodeStream: public BaseBytecodeStream {
+ public:
+ // Construction
+ RawBytecodeStream(const methodHandle& method) : BaseBytecodeStream(method) {
+ _is_raw = true;
+ }
+
+ public:
+ // Iteration
+ // Use raw_next() rather than next() for faster method reference
+ Bytecodes::Code raw_next() {
+ Bytecodes::Code code;
+ // set reading position
+ _bci = _next_bci;
+ assert(!is_last_bytecode(), "caller should check is_last_bytecode()");
+
+ address bcp = this->bcp();
+ code = Bytecodes::code_or_bp_at(bcp);
+
+ // set next bytecode position
+ int len = Bytecodes::length_for(code);
+ if (len > 0 && (_bci <= _end_bci - len)) {
+ assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch
+ && code != Bytecodes::_lookupswitch, "can't be special bytecode");
+ _is_wide = false;
+ _next_bci += len;
+ if (_next_bci <= _bci) { // Check for integer overflow
+ code = Bytecodes::_illegal;
+ }
+ _raw_code = code;
+ return code;
+ } else {
+ return raw_next_special(code);
+ }
+ }
+ Bytecodes::Code raw_next_special(Bytecodes::Code code);
+
+ // Unsigned indices, widening, with no swapping of bytes
+ int get_index() const { return (is_wide()) ? get_index_u2_raw(bcp() + 2) : get_index_u1(); }
+ // Get an unsigned 2-byte index, with no swapping of bytes.
+ int get_index_u2() const { assert(!is_wide(), ""); return get_index_u2_raw(bcp() + 1); }
+
+ private:
+ int get_index_u2_raw(address p) const {
+ assert_raw_index_size(2); assert_raw_stream(true);
+ return Bytes::get_Java_u2(p);
+ }
+};
+
+// In BytecodeStream, non-java bytecodes will be translated into the
+// corresponding java bytecodes.
+
+class BytecodeStream: public BaseBytecodeStream {
+ Bytecodes::Code _code;
+
+ public:
+ // Construction
+ BytecodeStream(const methodHandle& method) : BaseBytecodeStream(method) { }
+
+ // Iteration
+ Bytecodes::Code next() {
+ Bytecodes::Code raw_code, code;
+ // set reading position
+ _bci = _next_bci;
+ if (is_last_bytecode()) {
+ // indicate end of bytecode stream
+ raw_code = code = Bytecodes::_illegal;
+ } else {
+ // get bytecode
+ address bcp = this->bcp();
+ raw_code = Bytecodes::code_at(_method(), bcp);
+ code = Bytecodes::java_code(raw_code);
+ // set next bytecode position
+ //
+ // note that we cannot advance before having the
+ // tty bytecode otherwise the stepping is wrong!
+ // (carefull: length_for(...) must be used first!)
+ int len = Bytecodes::length_for(code);
+ if (len == 0) len = Bytecodes::length_at(_method(), bcp);
+ if (len <= 0 || (_bci > _end_bci - len) || (_bci - len >= _next_bci)) {
+ raw_code = code = Bytecodes::_illegal;
+ } else {
+ _next_bci += len;
+ assert(_bci < _next_bci, "length must be > 0");
+ // set attributes
+ _is_wide = false;
+ // check for special (uncommon) cases
+ if (code == Bytecodes::_wide) {
+ raw_code = (Bytecodes::Code)bcp[1];
+ code = raw_code; // wide BCs are always Java-normal
+ _is_wide = true;
+ }
+ assert(Bytecodes::is_java_code(code), "sanity check");
+ }
+ }
+ _raw_code = raw_code;
+ _code = code;
+ return _code;
+ }
+
+ bool is_active_breakpoint() const { return Bytecodes::is_active_breakpoint_at(bcp()); }
+ Bytecodes::Code code() const { return _code; }
+
+ // Unsigned indices, widening
+ int get_index() const { return is_wide() ? bytecode().get_index_u2(raw_code(), true) : get_index_u1(); }
+ // Get an unsigned 2-byte index, swapping the bytes if necessary.
+ int get_index_u2() const { assert_raw_stream(false);
+ return bytecode().get_index_u2(raw_code(), false); }
+ // Get an unsigned 2-byte index in native order.
+ int get_index_u2_cpcache() const { assert_raw_stream(false);
+ return bytecode().get_index_u2_cpcache(raw_code()); }
+ int get_index_u4() const { assert_raw_stream(false);
+ return bytecode().get_index_u4(raw_code()); }
+ bool has_index_u4() const { return bytecode().has_index_u4(raw_code()); }
+};
+
+#endif // SHARE_VM_INTERPRETER_BYTECODESTREAM_HPP