/*
* Copyright (c) 2000, 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.
*
*/
#include "precompiled.hpp"
#include "oops/oop.inline.hpp"
#include "oops/symbol.hpp"
#include "prims/jvmtiRedefineClassesTrace.hpp"
#include "prims/methodComparator.hpp"
#include "runtime/handles.inline.hpp"
#include "utilities/globalDefinitions.hpp"
BytecodeStream *MethodComparator::_s_old;
BytecodeStream *MethodComparator::_s_new;
constantPoolOop MethodComparator::_old_cp;
constantPoolOop MethodComparator::_new_cp;
BciMap *MethodComparator::_bci_map;
bool MethodComparator::_switchable_test;
GrowableArray<int> *MethodComparator::_fwd_jmps;
bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method) {
if (old_method->code_size() != new_method->code_size())
return false;
if (check_stack_and_locals_size(old_method, new_method) != 0) {
// RC_TRACE macro has an embedded ResourceMark
RC_TRACE(0x00800000, ("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;
_switchable_test = false;
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::methods_switchable(methodOop old_method, methodOop new_method,
BciMap &bci_map) {
if (old_method->code_size() > new_method->code_size())
// Something has definitely been deleted in the new method, compared to the old one.
return false;
if (! 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;
_bci_map = &bci_map;
_switchable_test = true;
GrowableArray<int> fwd_jmps(16);
_fwd_jmps = &fwd_jmps;
Bytecodes::Code c_old, c_new;
while ((c_old = s_old.next()) >= 0) {
if ((c_new = s_new.next()) < 0)
return false;
if (! (c_old == c_new && args_same(c_old, c_new))) {
int old_bci = s_old.bci();
int new_st_bci = s_new.bci();
bool found_match = false;
do {
c_new = s_new.next();
if (c_new == c_old && args_same(c_old, c_new)) {
found_match = true;
break;
}
} while (c_new >= 0);
if (! found_match)
return false;
int new_end_bci = s_new.bci();
bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
}
}
// Now we can test all forward jumps
for (int i = 0; i < fwd_jmps.length() / 2; i++) {
if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
RC_TRACE(0x00800000,
("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
fwd_jmps.at(i*2+1)));
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;
int cpi_old = _old_cp->cache()->main_entry_at(cpci_old)->constant_pool_index();
int cpi_new = _new_cp->cache()->main_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 (_switchable_test) {
int old_dest = _s_old->bci() + old_ofs;
int new_dest = _s_new->bci() + new_ofs;
if (old_ofs < 0 && new_ofs < 0) {
if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
return false;
} else if (old_ofs > 0 && new_ofs > 0) {
_fwd_jmps->append(old_dest);
_fwd_jmps->append(new_dest);
} else {
return false;
}
} else {
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 (_switchable_test) {
int old_dest = _s_old->bci() + old_ofs;
int new_dest = _s_new->bci() + new_ofs;
if (old_ofs < 0 && new_ofs < 0) {
if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
return false;
} else if (old_ofs > 0 && new_ofs > 0) {
_fwd_jmps->append(old_dest);
_fwd_jmps->append(new_dest);
} else {
return false;
}
} else {
if (old_ofs != new_ofs)
return false;
}
break;
}
case Bytecodes::_lookupswitch : // fall through
case Bytecodes::_tableswitch : {
if (_switchable_test) {
address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
_fwd_jmps->append(_s_old->bci() + default_old);
_fwd_jmps->append(_s_new->bci() + default_new);
if (c_old == Bytecodes::_lookupswitch) {
int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
if (npairs_old != npairs_new)
return false;
for (int i = 0; i < npairs_old; i++) {
int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
if (match_old != match_new)
return false;
int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
_fwd_jmps->append(_s_old->bci() + ofs_old);
_fwd_jmps->append(_s_new->bci() + ofs_new);
}
} else if (c_old == Bytecodes::_tableswitch) {
int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
if (lo_old != lo_new)
return false;
int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
if (hi_old != hi_new)
return false;
for (int i = 0; i < hi_old - lo_old + 1; i++) {
int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
_fwd_jmps->append(_s_old->bci() + ofs_old);
_fwd_jmps->append(_s_new->bci() + ofs_new);
}
}
} else { // !_switchable_test, can use fast rough compare
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;
}
}
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_old.is_unresolved_string()) {
if (! (tag_new.is_unresolved_string() || tag_new.is_string()))
return false;
if (strcmp(_old_cp->string_at_noresolve(cpi_old),
_new_cp->string_at_noresolve(cpi_new)) != 0)
return false;
} 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(methodOop old_method, methodOop 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;
}