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/*
* Copyright (c) 2000, 2018, 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.
*
*/
#include "precompiled.hpp"
#include "logging/log.hpp"
#include "memory/resourceArea.hpp"
#include "oops/constantPool.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/methodComparator.hpp"
#include "runtime/handles.inline.hpp"
#include "utilities/globalDefinitions.hpp"
BytecodeStream *MethodComparator::_s_old;
BytecodeStream *MethodComparator::_s_new;
ConstantPool* MethodComparator::_old_cp;
ConstantPool* MethodComparator::_new_cp;
bool MethodComparator::methods_EMCP(Method* old_method, Method* new_method) {
if (old_method->code_size() != new_method->code_size())
return false;
if (check_stack_and_locals_size(old_method, new_method) != 0) {
if (log_is_enabled(Debug, redefine, class, methodcomparator)) {
ResourceMark rm;
log_debug(redefine, class, methodcomparator)
("Methods %s non-comparable with diagnosis %d",
old_method->name()->as_C_string(), check_stack_and_locals_size(old_method, new_method));
}
return false;
}
_old_cp = old_method->constants();
_new_cp = new_method->constants();
BytecodeStream s_old(old_method);
BytecodeStream s_new(new_method);
_s_old = &s_old;
_s_new = &s_new;
Bytecodes::Code c_old, c_new;
while ((c_old = s_old.next()) >= 0) {
if ((c_new = s_new.next()) < 0 || c_old != c_new)
return false;
if (! args_same(c_old, c_new))
return false;
}
return true;
}
bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
// BytecodeStream returns the correct standard Java bytecodes for various "fast"
// bytecode versions, so we don't have to bother about them here..
switch (c_old) {
case Bytecodes::_new : // fall through
case Bytecodes::_anewarray : // fall through
case Bytecodes::_multianewarray : // fall through
case Bytecodes::_checkcast : // fall through
case Bytecodes::_instanceof : {
u2 cpi_old = _s_old->get_index_u2();
u2 cpi_new = _s_new->get_index_u2();
if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
return false;
if (c_old == Bytecodes::_multianewarray &&
*(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
return false;
break;
}
case Bytecodes::_getstatic : // fall through
case Bytecodes::_putstatic : // fall through
case Bytecodes::_getfield : // fall through
case Bytecodes::_putfield : // fall through
case Bytecodes::_invokevirtual : // fall through
case Bytecodes::_invokespecial : // fall through
case Bytecodes::_invokestatic : // fall through
case Bytecodes::_invokeinterface : {
int cpci_old = _s_old->get_index_u2_cpcache();
int cpci_new = _s_new->get_index_u2_cpcache();
// Check if the names of classes, field/method names and signatures at these indexes
// are the same. Indices which are really into constantpool cache (rather than constant
// pool itself) are accepted by the constantpool query routines below.
if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
(_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
(_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
return false;
break;
}
case Bytecodes::_invokedynamic: {
int cpci_old = _s_old->get_index_u4();
int cpci_new = _s_new->get_index_u4();
// Check if the names of classes, field/method names and signatures at these indexes
// are the same. Indices which are really into constantpool cache (rather than constant
// pool itself) are accepted by the constantpool query routines below.
if ((_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
(_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
return false;
// Translate object indexes to constant pool cache indexes.
cpci_old = _old_cp->invokedynamic_cp_cache_index(cpci_old);
cpci_new = _new_cp->invokedynamic_cp_cache_index(cpci_new);
int cpi_old = _old_cp->cache()->entry_at(cpci_old)->constant_pool_index();
int cpi_new = _new_cp->cache()->entry_at(cpci_new)->constant_pool_index();
int bsm_old = _old_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_old);
int bsm_new = _new_cp->invoke_dynamic_bootstrap_method_ref_index_at(cpi_new);
if (!pool_constants_same(bsm_old, bsm_new))
return false;
int cnt_old = _old_cp->invoke_dynamic_argument_count_at(cpi_old);
int cnt_new = _new_cp->invoke_dynamic_argument_count_at(cpi_new);
if (cnt_old != cnt_new)
return false;
for (int arg_i = 0; arg_i < cnt_old; arg_i++) {
int idx_old = _old_cp->invoke_dynamic_argument_index_at(cpi_old, arg_i);
int idx_new = _new_cp->invoke_dynamic_argument_index_at(cpi_new, arg_i);
if (!pool_constants_same(idx_old, idx_new))
return false;
}
break;
}
case Bytecodes::_ldc : // fall through
case Bytecodes::_ldc_w : {
Bytecode_loadconstant ldc_old(_s_old->method(), _s_old->bci());
Bytecode_loadconstant ldc_new(_s_new->method(), _s_new->bci());
int cpi_old = ldc_old.pool_index();
int cpi_new = ldc_new.pool_index();
if (!pool_constants_same(cpi_old, cpi_new))
return false;
break;
}
case Bytecodes::_ldc2_w : {
u2 cpi_old = _s_old->get_index_u2();
u2 cpi_new = _s_new->get_index_u2();
constantTag tag_old = _old_cp->tag_at(cpi_old);
constantTag tag_new = _new_cp->tag_at(cpi_new);
if (tag_old.value() != tag_new.value())
return false;
if (tag_old.is_long()) {
if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
return false;
} else {
// Use jlong_cast to compare the bits rather than numerical values.
// This makes a difference for NaN constants.
if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new)))
return false;
}
break;
}
case Bytecodes::_bipush :
if (_s_old->bcp()[1] != _s_new->bcp()[1])
return false;
break;
case Bytecodes::_sipush :
if (_s_old->get_index_u2() != _s_new->get_index_u2())
return false;
break;
case Bytecodes::_aload : // fall through
case Bytecodes::_astore : // fall through
case Bytecodes::_dload : // fall through
case Bytecodes::_dstore : // fall through
case Bytecodes::_fload : // fall through
case Bytecodes::_fstore : // fall through
case Bytecodes::_iload : // fall through
case Bytecodes::_istore : // fall through
case Bytecodes::_lload : // fall through
case Bytecodes::_lstore : // fall through
case Bytecodes::_ret :
if (_s_old->is_wide() != _s_new->is_wide())
return false;
if (_s_old->get_index() != _s_new->get_index())
return false;
break;
case Bytecodes::_goto : // fall through
case Bytecodes::_if_acmpeq : // fall through
case Bytecodes::_if_acmpne : // fall through
case Bytecodes::_if_icmpeq : // fall through
case Bytecodes::_if_icmpne : // fall through
case Bytecodes::_if_icmplt : // fall through
case Bytecodes::_if_icmpge : // fall through
case Bytecodes::_if_icmpgt : // fall through
case Bytecodes::_if_icmple : // fall through
case Bytecodes::_ifeq : // fall through
case Bytecodes::_ifne : // fall through
case Bytecodes::_iflt : // fall through
case Bytecodes::_ifge : // fall through
case Bytecodes::_ifgt : // fall through
case Bytecodes::_ifle : // fall through
case Bytecodes::_ifnonnull : // fall through
case Bytecodes::_ifnull : // fall through
case Bytecodes::_jsr : {
int old_ofs = _s_old->bytecode().get_offset_s2(c_old);
int new_ofs = _s_new->bytecode().get_offset_s2(c_new);
if (old_ofs != new_ofs)
return false;
break;
}
case Bytecodes::_iinc :
if (_s_old->is_wide() != _s_new->is_wide())
return false;
if (! _s_old->is_wide()) {
// We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once:
if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1))
return false;
} else {
// We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once:
if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
return false;
}
break;
case Bytecodes::_goto_w : // fall through
case Bytecodes::_jsr_w : {
int old_ofs = _s_old->bytecode().get_offset_s4(c_old);
int new_ofs = _s_new->bytecode().get_offset_s4(c_new);
if (old_ofs != new_ofs)
return false;
break;
}
case Bytecodes::_lookupswitch : // fall through
case Bytecodes::_tableswitch : {
int len_old = _s_old->instruction_size();
int len_new = _s_new->instruction_size();
if (len_old != len_new)
return false;
if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
return false;
break;
}
default:
break;
}
return true;
}
bool MethodComparator::pool_constants_same(int cpi_old, int cpi_new) {
constantTag tag_old = _old_cp->tag_at(cpi_old);
constantTag tag_new = _new_cp->tag_at(cpi_new);
if (tag_old.is_int() || tag_old.is_float()) {
if (tag_old.value() != tag_new.value())
return false;
if (tag_old.is_int()) {
if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
return false;
} else {
// Use jint_cast to compare the bits rather than numerical values.
// This makes a difference for NaN constants.
if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new)))
return false;
}
} else if (tag_old.is_string() && tag_new.is_string()) {
if (strcmp(_old_cp->string_at_noresolve(cpi_old),
_new_cp->string_at_noresolve(cpi_new)) != 0)
return false;
if (_old_cp->is_pseudo_string_at(cpi_old) || _new_cp->is_pseudo_string_at(cpi_new))
return (_old_cp->is_pseudo_string_at(cpi_old) == _new_cp->is_pseudo_string_at(cpi_new));
} else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) {
// tag_old should be klass - 4881222
if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
return false;
if (_old_cp->klass_at_noresolve(cpi_old) !=
_new_cp->klass_at_noresolve(cpi_new))
return false;
} else if (tag_old.is_method_type() && tag_new.is_method_type()) {
int mti_old = _old_cp->method_type_index_at(cpi_old);
int mti_new = _new_cp->method_type_index_at(cpi_new);
if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new)))
return false;
} else if (tag_old.is_method_handle() && tag_new.is_method_handle()) {
if (_old_cp->method_handle_ref_kind_at(cpi_old) !=
_new_cp->method_handle_ref_kind_at(cpi_new))
return false;
int mhi_old = _old_cp->method_handle_index_at(cpi_old);
int mhi_new = _new_cp->method_handle_index_at(cpi_new);
if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) ||
(_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) ||
(_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new)))
return false;
} else {
return false; // unknown tag
}
return true;
}
int MethodComparator::check_stack_and_locals_size(Method* old_method, Method* new_method) {
if (old_method->max_stack() != new_method->max_stack()) {
return 1;
} else if (old_method->max_locals() != new_method->max_locals()) {
return 2;
} else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
return 3;
} else return 0;
}