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/*
* Copyright (c) 1997, 2011, 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/methodOop.hpp"
#ifdef TARGET_ARCH_x86
# include "bytes_x86.hpp"
#endif
#ifdef TARGET_ARCH_sparc
# include "bytes_sparc.hpp"
#endif
#ifdef TARGET_ARCH_zero
# include "bytes_zero.hpp"
#endif
#ifdef TARGET_ARCH_arm
# include "bytes_arm.hpp"
#endif
#ifdef TARGET_ARCH_ppc
# include "bytes_ppc.hpp"
#endif
// A BytecodeStream is used for fast iteration over the bytecodes
// of a methodOop.
//
// 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(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
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(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 l = Bytecodes::length_for(code);
if (l > 0 && (_bci + l) <= _end_bci) {
assert(code != Bytecodes::_wide && code != Bytecodes::_tableswitch
&& code != Bytecodes::_lookupswitch, "can't be special bytecode");
_is_wide = false;
_next_bci += l;
_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(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 l = Bytecodes::length_for(code);
if (l == 0) l = Bytecodes::length_at(_method(), bcp);
_next_bci += l;
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
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