jdk/src/hotspot/share/interpreter/bytecodeTracer.cpp
Coleen Phillimore 7e4ac140d9 8380686: GenerateOopMap logging crashes in rewriter
Reviewed-by: matsaave, phubner
2026-03-27 19:55:32 +00:00

620 lines
23 KiB
C++

/*
* Copyright (c) 1997, 2026, 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 "classfile/classPrinter.hpp"
#include "classfile/javaClasses.inline.hpp"
#include "interpreter/bytecodeHistogram.hpp"
#include "interpreter/bytecodes.hpp"
#include "interpreter/bytecodeStream.hpp"
#include "interpreter/bytecodeTracer.hpp"
#include "interpreter/interpreter.hpp"
#include "memory/resourceArea.hpp"
#include "oops/constantPool.inline.hpp"
#include "oops/method.hpp"
#include "oops/methodData.hpp"
#include "runtime/atomicAccess.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/osThread.hpp"
#include "utilities/align.hpp"
// Prints the current bytecode and its attributes using bytecode-specific information.
class BytecodePrinter {
private:
// %%% This field is not GC-ed, and so can contain garbage
// between critical sections. Use only pointer-comparison
// operations on the pointer, except within a critical section.
// (Also, ensure that occasional false positives are benign.)
Method* _current_method;
bool _is_wide;
Bytecodes::Code _code;
address _next_pc; // current decoding position
int _flags;
bool _use_cp_cache;
bool use_cp_cache() const { return _use_cp_cache; }
void align() { _next_pc = align_up(_next_pc, sizeof(jint)); }
int get_byte() { return *(jbyte*) _next_pc++; } // signed
int get_index_u1() { return *(address)_next_pc++; } // returns 0x00 - 0xff as an int
short get_short() { short i = Bytes::get_Java_u2 (_next_pc); _next_pc += 2; return i; }
int get_int() { int i = Bytes::get_Java_u4 (_next_pc); _next_pc += 4; return i; }
int get_native_index_u2() { int i = Bytes::get_native_u2(_next_pc); _next_pc += 2; return i; }
int get_native_index_u4() { int i = Bytes::get_native_u4(_next_pc); _next_pc += 4; return i; }
int get_Java_index_u2() { int i = Bytes::get_Java_u2 (_next_pc); _next_pc += 2; return i; }
int get_Java_index_u4() { int i = Bytes::get_Java_u4 (_next_pc); _next_pc += 4; return i; }
int get_index_special() { return (is_wide()) ? get_Java_index_u2() : get_index_u1(); }
Method* method() const { return _current_method; }
bool is_wide() const { return _is_wide; }
Bytecodes::Code raw_code() const { return Bytecodes::Code(_code); }
ConstantPool* constants() const { return method()->constants(); }
ConstantPoolCache* cpcache() const { assert(use_cp_cache(), "must be"); return constants()->cache(); }
void print_constant(int i, outputStream* st);
void print_cpcache_entry(int cpc_index, outputStream* st);
void print_invokedynamic(int indy_index, int cp_index, outputStream* st);
void print_bsm(int cp_index, outputStream* st);
void print_field_or_method(int cp_index, outputStream* st);
void print_dynamic(int cp_index, outputStream* st);
void print_attributes(int bci, outputStream* st);
void print_method_data_at(int bci, outputStream* st);
public:
BytecodePrinter(int flags = 0) : _is_wide(false), _code(Bytecodes::_illegal), _flags(flags) {}
#ifndef PRODUCT
BytecodePrinter(Method* prev_method) : BytecodePrinter(0) {
_current_method = prev_method;
}
// This method is called while executing the raw bytecodes, so none of
// the adjustments that BytecodeStream performs applies.
void trace(const methodHandle& method, address bcp, uintptr_t tos, uintptr_t tos2, outputStream* st) {
ResourceMark rm;
bool method_changed = _current_method != method();
_current_method = method();
_use_cp_cache = method->constants()->cache() != nullptr;
assert(method->method_holder()->is_linked(),
"this function must be called on methods that are already executing");
if (method_changed) {
// Note 1: This code will not work as expected with true MT/MP.
// Need an explicit lock or a different solution.
// It is possible for this block to be skipped, if a garbage
// _current_method pointer happens to have the same bits as
// the incoming method. We could lose a line of trace output.
// This is acceptable in a debug-only feature.
st->cr();
st->print("[%zu] ", Thread::current()->osthread()->thread_id_for_printing());
method->print_name(st);
st->cr();
}
Bytecodes::Code code;
if (is_wide()) {
// bcp wasn't advanced if previous bytecode was _wide.
code = Bytecodes::code_at(method(), bcp+1);
} else {
code = Bytecodes::code_at(method(), bcp);
}
_code = code;
_next_pc = is_wide() ? bcp+2 : bcp+1;
// Trace each bytecode unless we're truncating the tracing output, then only print the first
// bytecode in every method as well as returns/throws that pop control flow
if (!TraceBytecodesTruncated || method_changed ||
code == Bytecodes::_athrow ||
code == Bytecodes::_return_register_finalizer ||
(code >= Bytecodes::_ireturn && code <= Bytecodes::_return)) {
int bci = (int)(bcp - method->code_base());
st->print("[%zu] ", Thread::current()->osthread()->thread_id_for_printing());
if (Verbose) {
st->print("%8zu %4d " INTPTR_FORMAT " " INTPTR_FORMAT " %s",
BytecodeCounter::counter_value(), bci, tos, tos2, Bytecodes::name(code));
} else {
st->print("%8zu %4d %s",
BytecodeCounter::counter_value(), bci, Bytecodes::name(code));
}
print_attributes(bci, st);
}
// Set is_wide for the next one, since the caller of this doesn't skip
// the next bytecode.
_is_wide = (code == Bytecodes::_wide);
_code = Bytecodes::_illegal;
if (TraceBytecodesStopAt != 0 && BytecodeCounter::counter_value() >= TraceBytecodesStopAt) {
TraceBytecodes = false;
}
}
#endif
// Used for Method::print_codes(). The input bcp comes from
// BytecodeStream, which will skip wide bytecodes.
void trace(const methodHandle& method, address bcp, outputStream* st) {
_current_method = method();
// This may be called during linking after bytecodes are rewritten to point to the cpCache.
_use_cp_cache = method->constants()->cache() != nullptr;
ResourceMark rm;
Bytecodes::Code code = Bytecodes::code_at(method(), bcp);
// Set is_wide
_is_wide = (code == Bytecodes::_wide);
if (is_wide()) {
code = Bytecodes::code_at(method(), bcp+1);
}
_code = code;
int bci = (int)(bcp - method->code_base());
// Print bytecode index and name
if (ClassPrinter::has_mode(_flags, ClassPrinter::PRINT_BYTECODE_ADDR)) {
st->print(INTPTR_FORMAT " ", p2i(bcp));
}
if (is_wide()) {
st->print("%4d %s_w", bci, Bytecodes::name(code));
} else {
st->print("%4d %s", bci, Bytecodes::name(code));
}
_next_pc = is_wide() ? bcp+2 : bcp+1;
print_attributes(bci, st);
if (ClassPrinter::has_mode(_flags, ClassPrinter::PRINT_METHOD_DATA)) {
print_method_data_at(bci, st);
}
}
};
#ifndef PRODUCT
// We need a global instance to keep track of the method being printed so we can report that
// the method has changed. If this method is redefined and removed, that's ok because the method passed
// in won't match, and this will print the method passed in again. Racing threads changing this global
// will result in reprinting the method passed in again.
static Method* _method_currently_being_printed = nullptr;
void BytecodeTracer::trace_interpreter(const methodHandle& method, address bcp, uintptr_t tos, uintptr_t tos2, outputStream* st) {
if (TraceBytecodes && BytecodeCounter::counter_value() >= TraceBytecodesAt) {
BytecodePrinter printer(AtomicAccess::load_acquire(&_method_currently_being_printed));
stringStream buf;
printer.trace(method, bcp, tos, tos2, &buf);
st->print("%s", buf.freeze());
// Save method currently being printed to detect when method printing changes.
AtomicAccess::release_store(&_method_currently_being_printed, method());
}
}
#endif
void BytecodeTracer::print_method_codes(const methodHandle& method, int from, int to, outputStream* st, int flags, bool buffered) {
BytecodePrinter method_printer(flags);
BytecodeStream s(method);
s.set_interval(from, to);
ResourceMark rm;
stringStream ss;
outputStream* out = buffered ? &ss : st;
while (s.next() >= 0) {
method_printer.trace(method, s.bcp(), out);
}
if (buffered) {
st->print("%s", ss.as_string());
}
}
void BytecodePrinter::print_constant(int cp_index, outputStream* st) {
ConstantPool* constants = method()->constants();
constantTag tag = constants->tag_at(cp_index);
if (tag.is_int()) {
st->print_cr(" " INT32_FORMAT, constants->int_at(cp_index));
} else if (tag.is_long()) {
st->print_cr(" " INT64_FORMAT, (int64_t)(constants->long_at(cp_index)));
} else if (tag.is_float()) {
st->print_cr(" %f", constants->float_at(cp_index));
} else if (tag.is_double()) {
st->print_cr(" %f", constants->double_at(cp_index));
} else if (tag.is_string()) {
const char* string = constants->unresolved_string_at(cp_index)->as_quoted_ascii();
st->print_cr(" \"%s\"", string);
} else if (tag.is_klass()) {
st->print_cr(" %s", constants->resolved_klass_at(cp_index)->external_name());
} else if (tag.is_unresolved_klass()) {
st->print_cr(" %s", constants->klass_at_noresolve(cp_index)->as_quoted_ascii());
} else if (tag.is_method_type()) {
int i2 = constants->method_type_index_at(cp_index);
st->print(" <MethodType> %d", i2);
st->print_cr(" %s", constants->symbol_at(i2)->as_quoted_ascii());
} else if (tag.is_method_handle()) {
int kind = constants->method_handle_ref_kind_at(cp_index);
int i2 = constants->method_handle_index_at(cp_index);
st->print(" <MethodHandle of kind %d index at %d>", kind, i2);
print_field_or_method(i2, st);
} else if (tag.is_dynamic_constant()) {
print_dynamic(cp_index, st);
if (ClassPrinter::has_mode(_flags, ClassPrinter::PRINT_DYNAMIC)) {
print_bsm(cp_index, st);
}
} else {
st->print_cr(" bad tag=%d at %d", tag.value(), cp_index);
}
}
// Fieldref, Methodref, or InterfaceMethodref
void BytecodePrinter::print_field_or_method(int cp_index, outputStream* st) {
ConstantPool* constants = method()->constants();
constantTag tag = constants->tag_at(cp_index);
switch (tag.value()) {
case JVM_CONSTANT_Fieldref:
case JVM_CONSTANT_Methodref:
case JVM_CONSTANT_InterfaceMethodref:
break;
default:
st->print_cr(" bad tag=%d at %d", tag.value(), cp_index);
return;
}
Symbol* name = constants->uncached_name_ref_at(cp_index);
Symbol* signature = constants->uncached_signature_ref_at(cp_index);
Symbol* klass = constants->klass_name_at(constants->uncached_klass_ref_index_at(cp_index));
const char* sep = (tag.is_field() ? ":" : "");
st->print_cr(" %d <%s.%s%s%s> ", cp_index, klass->as_C_string(), name->as_C_string(), sep, signature->as_C_string());
}
// JVM_CONSTANT_Dynamic or JVM_CONSTANT_InvokeDynamic
void BytecodePrinter::print_dynamic(int cp_index, outputStream* st) {
ConstantPool* constants = method()->constants();
constantTag tag = constants->tag_at(cp_index);
switch (tag.value()) {
case JVM_CONSTANT_Dynamic:
case JVM_CONSTANT_InvokeDynamic:
break;
default:
st->print_cr(" bad tag=%d at %d", tag.value(), cp_index);
return;
}
int bsm = constants->bootstrap_method_ref_index_at(cp_index);
st->print(" bsm=%d", bsm);
Symbol* name = constants->uncached_name_ref_at(cp_index);
Symbol* signature = constants->uncached_signature_ref_at(cp_index);
const char* sep = tag.is_dynamic_constant() ? ":" : "";
st->print_cr(" %d <%s%s%s>", cp_index, name->as_C_string(), sep, signature->as_C_string());
}
void BytecodePrinter::print_invokedynamic(int indy_index, int cp_index, outputStream* st) {
print_dynamic(cp_index, st);
if (ClassPrinter::has_mode(_flags, ClassPrinter::PRINT_DYNAMIC)) {
print_bsm(cp_index, st);
if (use_cp_cache()) {
ResolvedIndyEntry* indy_entry = constants()->resolved_indy_entry_at(indy_index);
st->print(" ResolvedIndyEntry: ");
indy_entry->print_on(st);
}
}
}
// cp_index: must be the cp_index of a JVM_CONSTANT_{Dynamic, DynamicInError, InvokeDynamic}
void BytecodePrinter::print_bsm(int cp_index, outputStream* st) {
assert(constants()->tag_at(cp_index).has_bootstrap(), "must be");
int bsm = constants()->bootstrap_method_ref_index_at(cp_index);
const char* ref_kind = "";
switch (constants()->method_handle_ref_kind_at(bsm)) {
case JVM_REF_getField : ref_kind = "REF_getField"; break;
case JVM_REF_getStatic : ref_kind = "REF_getStatic"; break;
case JVM_REF_putField : ref_kind = "REF_putField"; break;
case JVM_REF_putStatic : ref_kind = "REF_putStatic"; break;
case JVM_REF_invokeVirtual : ref_kind = "REF_invokeVirtual"; break;
case JVM_REF_invokeStatic : ref_kind = "REF_invokeStatic"; break;
case JVM_REF_invokeSpecial : ref_kind = "REF_invokeSpecial"; break;
case JVM_REF_newInvokeSpecial : ref_kind = "REF_newInvokeSpecial"; break;
case JVM_REF_invokeInterface : ref_kind = "REF_invokeInterface"; break;
default : ShouldNotReachHere();
}
st->print(" BSM: %s", ref_kind);
print_field_or_method(constants()->method_handle_index_at(bsm), st);
int argc = constants()->bootstrap_argument_count_at(cp_index);
st->print(" arguments[%d] = {", argc);
if (argc > 0) {
st->cr();
for (int arg_i = 0; arg_i < argc; arg_i++) {
int arg = constants()->bootstrap_argument_index_at(cp_index, arg_i);
st->print(" ");
print_constant(arg, st);
}
}
st->print_cr(" }");
}
void BytecodePrinter::print_attributes(int bci, outputStream* st) {
// Show attributes of pre-rewritten codes
Bytecodes::Code code = Bytecodes::java_code(raw_code());
// If the code doesn't have any fields there's nothing to print.
// note this is ==1 because the tableswitch and lookupswitch are
// zero size (for some reason) and we want to print stuff out for them.
// Also skip this if we're truncating bytecode output
if (TraceBytecodesTruncated || Bytecodes::length_for(code) == 1) {
st->cr();
return;
}
switch(code) {
// Java specific bytecodes only matter.
case Bytecodes::_bipush:
st->print_cr(" " INT32_FORMAT, get_byte());
break;
case Bytecodes::_sipush:
st->print_cr(" " INT32_FORMAT, get_short());
break;
case Bytecodes::_ldc:
{
int cp_index;
if (Bytecodes::uses_cp_cache(raw_code())) {
assert(use_cp_cache(), "fast ldc bytecode must be in linked classes");
int obj_index = get_index_u1();
cp_index = constants()->object_to_cp_index(obj_index);
} else {
cp_index = get_index_u1();
}
print_constant(cp_index, st);
}
break;
case Bytecodes::_ldc_w:
case Bytecodes::_ldc2_w:
{
int cp_index;
if (Bytecodes::uses_cp_cache(raw_code())) {
assert(use_cp_cache(), "fast ldc bytecode must be in linked classes");
int obj_index = get_native_index_u2();
cp_index = constants()->object_to_cp_index(obj_index);
} else {
cp_index = get_Java_index_u2();
}
print_constant(cp_index, st);
}
break;
case Bytecodes::_iload:
case Bytecodes::_lload:
case Bytecodes::_fload:
case Bytecodes::_dload:
case Bytecodes::_aload:
case Bytecodes::_istore:
case Bytecodes::_lstore:
case Bytecodes::_fstore:
case Bytecodes::_dstore:
case Bytecodes::_astore:
st->print_cr(" #%d", get_index_special());
break;
case Bytecodes::_iinc:
{ int index = get_index_special();
jint offset = is_wide() ? get_short(): get_byte();
st->print_cr(" #%d " INT32_FORMAT, index, offset);
}
break;
case Bytecodes::_newarray: {
BasicType atype = (BasicType)get_index_u1();
const char* str = type2name(atype);
if (str == nullptr || is_reference_type(atype)) {
assert(false, "Unidentified basic type");
}
st->print_cr(" %s", str);
}
break;
case Bytecodes::_anewarray: {
int klass_index = get_Java_index_u2();
ConstantPool* constants = method()->constants();
Symbol* name = constants->klass_name_at(klass_index);
st->print_cr(" %s ", name->as_C_string());
}
break;
case Bytecodes::_multianewarray: {
int klass_index = get_Java_index_u2();
int nof_dims = get_index_u1();
ConstantPool* constants = method()->constants();
Symbol* name = constants->klass_name_at(klass_index);
st->print_cr(" %s %d", name->as_C_string(), nof_dims);
}
break;
case Bytecodes::_ifeq:
case Bytecodes::_ifnull:
case Bytecodes::_iflt:
case Bytecodes::_ifle:
case Bytecodes::_ifne:
case Bytecodes::_ifnonnull:
case Bytecodes::_ifgt:
case Bytecodes::_ifge:
case Bytecodes::_if_icmpeq:
case Bytecodes::_if_icmpne:
case Bytecodes::_if_icmplt:
case Bytecodes::_if_icmpgt:
case Bytecodes::_if_icmple:
case Bytecodes::_if_icmpge:
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
case Bytecodes::_goto:
case Bytecodes::_jsr:
st->print_cr(" %d", bci + get_short());
break;
case Bytecodes::_goto_w:
case Bytecodes::_jsr_w:
st->print_cr(" %d", bci + get_int());
break;
case Bytecodes::_ret: st->print_cr(" %d", get_index_special()); break;
case Bytecodes::_tableswitch:
{ align();
int default_dest = bci + get_int();
int lo = get_int();
int hi = get_int();
int len = hi - lo + 1;
jint* dest = NEW_RESOURCE_ARRAY(jint, len);
for (int i = 0; i < len; i++) {
dest[i] = bci + get_int();
}
st->print(" %d " INT32_FORMAT " " INT32_FORMAT " ",
default_dest, lo, hi);
const char *comma = "";
for (int ll = lo; ll <= hi; ll++) {
int idx = ll - lo;
st->print("%s %d:" INT32_FORMAT " (delta: %d)", comma, ll, dest[idx], dest[idx]-bci);
comma = ",";
}
st->cr();
}
break;
case Bytecodes::_lookupswitch:
{ align();
int default_dest = bci + get_int();
int len = get_int();
jint* key = NEW_RESOURCE_ARRAY(jint, len);
jint* dest = NEW_RESOURCE_ARRAY(jint, len);
for (int i = 0; i < len; i++) {
key [i] = get_int();
dest[i] = bci + get_int();
};
st->print(" %d %d ", default_dest, len);
const char *comma = "";
for (int ll = 0; ll < len; ll++) {
st->print("%s " INT32_FORMAT ":" INT32_FORMAT, comma, key[ll], dest[ll]);
comma = ",";
}
st->cr();
}
break;
case Bytecodes::_putstatic:
case Bytecodes::_getstatic:
case Bytecodes::_putfield:
case Bytecodes::_getfield:
{
int cp_index;
if (use_cp_cache()) {
int field_index = get_native_index_u2();
cp_index = cpcache()->resolved_field_entry_at(field_index)->constant_pool_index();
} else {
cp_index = get_Java_index_u2();
}
print_field_or_method(cp_index, st);
}
break;
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
{
int cp_index;
if (use_cp_cache()) {
int method_index = get_native_index_u2();
ResolvedMethodEntry* method_entry = cpcache()->resolved_method_entry_at(method_index);
cp_index = method_entry->constant_pool_index();
print_field_or_method(cp_index, st);
if (raw_code() == Bytecodes::_invokehandle &&
ClassPrinter::has_mode(_flags, ClassPrinter::PRINT_METHOD_HANDLE)) {
assert(use_cp_cache(), "invokehandle is only in rewritten methods");
method_entry->print_on(st);
if (method_entry->has_appendix()) {
st->print(" appendix: ");
constants()->resolved_reference_from_method(method_index)->print_on(st);
}
}
} else {
cp_index = get_Java_index_u2();
print_field_or_method(cp_index, st);
}
}
break;
case Bytecodes::_invokeinterface:
{
int cp_index;
if (use_cp_cache()) {
int method_index = get_native_index_u2();
cp_index = cpcache()->resolved_method_entry_at(method_index)->constant_pool_index();
} else {
cp_index = get_Java_index_u2();
}
int count = get_index_u1(); // TODO: this is not printed.
get_byte(); // ignore zero byte
print_field_or_method(cp_index, st);
}
break;
case Bytecodes::_invokedynamic:
{
int indy_index;
int cp_index;
if (use_cp_cache()) {
indy_index = get_native_index_u4();
cp_index = constants()->resolved_indy_entry_at(indy_index)->constant_pool_index();
} else {
indy_index = -1;
cp_index = get_Java_index_u2();
get_byte(); // ignore zero byte
get_byte(); // ignore zero byte
}
print_invokedynamic(indy_index, cp_index, st);
}
break;
case Bytecodes::_new:
case Bytecodes::_checkcast:
case Bytecodes::_instanceof:
{ int i = get_Java_index_u2();
ConstantPool* constants = method()->constants();
Symbol* name = constants->klass_name_at(i);
st->print_cr(" %d <%s>", i, name->as_C_string());
}
break;
case Bytecodes::_wide:
// length is zero not one, but printed with no more info.
break;
default:
ShouldNotReachHere();
break;
}
}
void BytecodePrinter::print_method_data_at(int bci, outputStream* st) {
MethodData* mdo = method()->method_data();
if (mdo != nullptr) {
// Lock to read ProfileData, and ensure lock is not broken by a safepoint
MutexLocker ml(mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
ProfileData* data = mdo->bci_to_data(bci);
if (data != nullptr) {
st->print(" %d ", mdo->dp_to_di(data->dp()));
st->fill_to(7);
data->print_data_on(st, mdo);
}
}
}