JDK14/Java14源码在线阅读
/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2019 SAP SE. 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 "classfile/systemDictionary.hpp"
#include "gc/shared/gcLocker.hpp"
#include "interpreter/bytecodeUtils.hpp"
#include "memory/resourceArea.hpp"
#include "runtime/signature.hpp"
#include "runtime/safepointVerifiers.hpp"
#include "utilities/events.hpp"
#include "utilities/ostream.hpp"
class SimulatedOperandStack;
class ExceptionMessageBuilder;
// The entries of a SimulatedOperandStack. They carry the analysis
// information gathered for the slot.
class StackSlotAnalysisData {
private:
friend class SimulatedOperandStack;
friend class ExceptionMessageBuilder;
unsigned int _bci:17; // The bci of the bytecode that pushed the current value on the operand stack.
// INVALID if ambiguous, e.g. after a control flow merge.
// 16 bits for bci (max bytecode size) and one for INVALID.
unsigned int _type:15; // The BasicType of the value on the operand stack.
// Merges this slot data with the given one and returns the result. If
// the bcis of the two merged objects are different, the bci of the result
// will be undefined. If the types are different, the result type is T_CONFLICT.
// (An exception is if one type is an array and the other is object, then
// the result type will be T_OBJECT).
StackSlotAnalysisData merge(StackSlotAnalysisData other);
public:
// Creates a new object with an invalid bci and the given type.
StackSlotAnalysisData(BasicType type = T_CONFLICT);
// Creates a new object with the given bci and type.
StackSlotAnalysisData(int bci, BasicType type);
enum {
// An invalid bytecode index, as > 65535.
INVALID = 0x1FFFF
};
// Returns the bci. If the bci is invalid, INVALID is returned.
unsigned int get_bci();
// Returns true, if the bci is not invalid.
bool has_bci() { return get_bci() != INVALID; }
// Returns the type of the slot data.
BasicType get_type();
};
// A stack consisting of SimulatedOperandStackEntries.
// This represents the analysis information for the operand stack
// for a given bytecode at a given bci.
// It also holds an additional field that serves to collect
// information whether local slots were written.
class SimulatedOperandStack: CHeapObj<mtInternal> {
private:
friend class ExceptionMessageBuilder;
friend class StackSlotAnalysisData;
// The stack.
GrowableArray<StackSlotAnalysisData> _stack;
// Optimized bytecode can reuse local variable slots for several
// local variables.
// If there is no variable name information, we print 'parameter<i>'
// if a parameter maps to a local slot. Once a local slot has been
// written, we don't know any more whether it was written as the
// corresponding parameter, or whether another local has been
// mapped to the slot. So we don't want to print 'parameter<i>' any
// more, but 'local<i>'. Similary for 'this'.
// Therefore, during the analysis, we mark a bit for local slots that
// get written and propagate this information.
// We only run the analysis for 64 slots. If a method has more
// parameters, we print 'local<i>' in all cases.
uint64_t _written_local_slots;
SimulatedOperandStack(): _written_local_slots(0) { };
SimulatedOperandStack(const SimulatedOperandStack ©);
// Pushes the given slot data.
void push_raw(StackSlotAnalysisData slotData);
// Like push_raw, but if the slotData has type long or double, we push two.
void push(StackSlotAnalysisData slotData);
// Like push(slotData), but using bci/type to create an instance of
// StackSlotAnalysisData first.
void push(int bci, BasicType type);
// Pops the given number of entries.
void pop(int slots);
// Merges this with the given stack by merging all entries. The
// size of the stacks must be the same.
void merge(SimulatedOperandStack const& other);
public:
// Returns the size of the stack.
int get_size() const;
// Returns the slot data at the given index. Slot 0 is top of stack.
StackSlotAnalysisData get_slot_data(int slot);
// Mark that local slot i was written.
void set_local_slot_written(int i);
// Check whether local slot i was written by this or a previous bytecode.
bool local_slot_was_written(int i);
};
// Helper class to build internal exception messages for exceptions
// that are thrown because prerequisites to execute a bytecode
// are not met.
// E.g., if a NPE is thrown because an iload can not be executed
// by the VM because the reference to load from is null.
//
// It analyses the bytecode to assemble Java-like message text
// to give precise information where in a larger expression the
// exception occured.
//
// To assemble this message text, it is needed to know how
// operand stack slot entries were pushed on the operand stack.
// This class contains an analysis over the bytecodes to compute
// this information. The information is stored in a
// SimulatedOperandStack for each bytecode.
class ExceptionMessageBuilder : public StackObj {
// The stacks for each bytecode.
GrowableArray<SimulatedOperandStack*>* _stacks;
// The method.
Method* _method;
// The number of entries used (the sum of all entries of all stacks).
int _nr_of_entries;
// If true, we have added at least one new stack.
bool _added_one;
// If true, we have processed all bytecodes.
bool _all_processed;
// The maximum number of entries we want to use. This is used to
// limit the amount of memory we waste for insane methods (as they
// appear in JCK tests).
static const int _max_entries = 1000000;
static const int _max_cause_detail = 5;
// Merges the stack the the given bci with the given stack. If there
// is no stack at the bci, we just put the given stack there. This
// method doesn't takes ownership of the stack.
void merge(int bci, SimulatedOperandStack* stack);
// Processes the instruction at the given bci in the method. Returns
// the size of the instruction.
int do_instruction(int bci);
bool print_NPE_cause0(outputStream *os, int bci, int slot, int max_detail,
bool inner_expr = false, const char *prefix = NULL);
public:
// Creates an ExceptionMessageBuilder object and runs the analysis
// building SimulatedOperandStacks for each bytecode in the given
// method (the method must be rewritten already). Note that you're
// not allowed to use this object when crossing a safepoint! If the
// bci is != -1, we only create the stacks as far as needed to get a
// stack for the bci.
ExceptionMessageBuilder(Method* method, int bci = -1);
// Releases the resources.
~ExceptionMessageBuilder();
// Returns the number of stacks (this is the size of the method).
int get_size() { return _stacks->length() - 1; }
// Assuming that a NullPointerException was thrown at the given bci,
// we return the nr of the slot holding the null reference. If this
// NPE is created by hand, we return -2 as the slot. If there
// cannot be a NullPointerException at the bci, -1 is returned.
int get_NPE_null_slot(int bci);
// Prints a java-like expression for the bytecode that pushed
// the value to the given slot being live at the given bci.
// It constructs the expression by recursing backwards over the
// bytecode using the results of the analysis done in the
// constructor of ExceptionMessageBuilder.
// os: The stream to print the message to.
// bci: The index of the bytecode that caused the NPE.
// slot: The slot on the operand stack that contains null.
// The slots are numbered from TOS downwards, i.e.,
// TOS has the slot number 0, that below 1 and so on.
//
// Returns false if nothing was printed, else true.
bool print_NPE_cause(outputStream *os, int bci, int slot);
// Prints a string describing the failed action.
void print_NPE_failed_action(outputStream *os, int bci);
};
// Replaces the following well-known class names:
// java.lang.Object -> Object
// java.lang.String -> String
static char *trim_well_known_class_names_from_signature(char *signature) {
size_t len = strlen(signature);
size_t skip_len = strlen("java.lang.");
size_t min_pattern_len = strlen("java.lang.String");
if (len < min_pattern_len) return signature;
for (size_t isrc = 0, idst = 0; isrc <= len; isrc++, idst++) {
// We must be careful not to trim names like test.java.lang.String.
if ((isrc == 0 && strncmp(signature + isrc, "java.lang.Object", min_pattern_len) == 0) ||
(isrc == 0 && strncmp(signature + isrc, "java.lang.String", min_pattern_len) == 0) ||
(isrc > 1 && strncmp(signature + isrc-2, ", java.lang.Object", min_pattern_len+2) == 0) ||
(isrc > 1 && strncmp(signature + isrc-2, ", java.lang.String", min_pattern_len+2) == 0) ) {
isrc += skip_len;
}
if (idst != isrc) {
signature[idst] = signature[isrc];
}
}
return signature;
}
// Replaces the following well-known class names:
// java.lang.Object -> Object
// java.lang.String -> String
static void print_klass_name(outputStream *os, Symbol *klass) {
const char *name = klass->as_klass_external_name();
if (strcmp(name, "java.lang.Object") == 0) name = "Object";
if (strcmp(name, "java.lang.String") == 0) name = "String";
os->print("%s", name);
}
// Prints the name of the method that is described at constant pool
// index cp_index in the constant pool of method 'method'.
static void print_method_name(outputStream *os, Method* method, int cp_index) {
ResourceMark rm;
ConstantPool* cp = method->constants();
Symbol* klass = cp->klass_ref_at_noresolve(cp_index);
Symbol* name = cp->name_ref_at(cp_index);
Symbol* signature = cp->signature_ref_at(cp_index);
print_klass_name(os, klass);
os->print(".%s(", name->as_C_string());
stringStream sig;
signature->print_as_signature_external_parameters(&sig);
os->print("%s)", trim_well_known_class_names_from_signature(sig.as_string()));
}
// Prints the name of the field that is described at constant pool
// index cp_index in the constant pool of method 'method'.
static void print_field_and_class(outputStream *os, Method* method, int cp_index) {
ResourceMark rm;
ConstantPool* cp = method->constants();
Symbol* klass = cp->klass_ref_at_noresolve(cp_index);
Symbol *name = cp->name_ref_at(cp_index);
print_klass_name(os, klass);
os->print(".%s", name->as_C_string());
}
// Returns the name of the field that is described at constant pool
// index cp_index in the constant pool of method 'method'.
static char const* get_field_name(Method* method, int cp_index) {
Symbol* name = method->constants()->name_ref_at(cp_index);
return name->as_C_string();
}
static void print_local_var(outputStream *os, unsigned int bci, Method* method, int slot, bool is_parameter) {
if (method->has_localvariable_table()) {
for (int i = 0; i < method->localvariable_table_length(); i++) {
LocalVariableTableElement* elem = method->localvariable_table_start() + i;
unsigned int start = elem->start_bci;
unsigned int end = start + elem->length;
if ((bci >= start) && (bci < end) && (elem->slot == slot)) {
ConstantPool* cp = method->constants();
char *var = cp->symbol_at(elem->name_cp_index)->as_C_string();
os->print("%s", var);
return;
}
}
}
// Handle at least some cases we know.
if (!method->is_static() && (slot == 0) && is_parameter) {
os->print("this");
} else {
int curr = method->is_static() ? 0 : 1;
SignatureStream ss(method->signature());
int param_index = 1;
bool found = false;
for (SignatureStream ss(method->signature()); !ss.is_done(); ss.next()) {
if (ss.at_return_type()) {
continue;
}
int size = type2size[ss.type()];
if ((slot >= curr) && (slot < curr + size)) {
found = true;
break;
}
param_index += 1;
curr += size;
}
if (found && is_parameter) {
os->print("<parameter%d>", param_index);
} else {
// This is the best we can do.
os->print("<local%d>", slot);
}
}
}
StackSlotAnalysisData::StackSlotAnalysisData(BasicType type) : _bci(INVALID), _type(type) {}
StackSlotAnalysisData::StackSlotAnalysisData(int bci, BasicType type) : _bci(bci), _type(type) {
assert(bci >= 0, "BCI must be >= 0");
assert(bci < 65536, "BCI must be < 65536");
}
unsigned int StackSlotAnalysisData::get_bci() {
return _bci;
}
BasicType StackSlotAnalysisData::get_type() {
return (BasicType)_type;
}
StackSlotAnalysisData StackSlotAnalysisData::merge(StackSlotAnalysisData other) {
if (get_type() != other.get_type()) {
if (((get_type() == T_OBJECT) || (get_type() == T_ARRAY)) &&
((other.get_type() == T_OBJECT) || (other.get_type() == T_ARRAY))) {
if (get_bci() == other.get_bci()) {
return StackSlotAnalysisData(get_bci(), T_OBJECT);
} else {
return StackSlotAnalysisData(T_OBJECT);
}
} else {
return StackSlotAnalysisData(T_CONFLICT);
}
}
if (get_bci() == other.get_bci()) {
return *this;
} else {
return StackSlotAnalysisData(get_type());
}
}
SimulatedOperandStack::SimulatedOperandStack(const SimulatedOperandStack ©) {
for (int i = 0; i < copy.get_size(); i++) {
push_raw(copy._stack.at(i));
}
_written_local_slots = copy._written_local_slots;
}
void SimulatedOperandStack::push_raw(StackSlotAnalysisData slotData) {
if (slotData.get_type() == T_VOID) {
return;
}
_stack.push(slotData);
}
void SimulatedOperandStack::push(StackSlotAnalysisData slotData) {
if (type2size[slotData.get_type()] == 2) {
push_raw(slotData);
push_raw(slotData);
} else {
push_raw(slotData);
}
}
void SimulatedOperandStack::push(int bci, BasicType type) {
push(StackSlotAnalysisData(bci, type));
}
void SimulatedOperandStack::pop(int slots) {
for (int i = 0; i < slots; ++i) {
_stack.pop();
}
assert(get_size() >= 0, "Popped too many slots");
}
void SimulatedOperandStack::merge(SimulatedOperandStack const& other) {
assert(get_size() == other.get_size(), "Stacks not of same size");
for (int i = get_size() - 1; i >= 0; --i) {
_stack.at_put(i, _stack.at(i).merge(other._stack.at(i)));
}
_written_local_slots = _written_local_slots | other._written_local_slots;
}
int SimulatedOperandStack::get_size() const {
return _stack.length();
}
StackSlotAnalysisData SimulatedOperandStack::get_slot_data(int slot) {
assert(slot >= 0, "Slot=%d < 0", slot);
assert(slot < get_size(), "Slot=%d >= size=%d", slot, get_size());
return _stack.at(get_size() - slot - 1);
}
void SimulatedOperandStack::set_local_slot_written(int i) {
// Local slots > 63 are very unlikely. Consider these
// as written all the time. Saves space and complexity
// for dynamic data size.
if (i > 63) return;
_written_local_slots = _written_local_slots | (1ULL << i);
}
bool SimulatedOperandStack::local_slot_was_written(int i) {
if (i > 63) return true;
return (_written_local_slots & (1ULL << i)) != 0;
}
ExceptionMessageBuilder::ExceptionMessageBuilder(Method* method, int bci) :
_method(method), _nr_of_entries(0),
_added_one(true), _all_processed(false) {
ConstMethod* const_method = method->constMethod();
const int len = const_method->code_size();
assert(bci >= 0, "BCI too low: %d", bci);
assert(bci < len, "BCI too large: %d size: %d", bci, len);
_stacks = new GrowableArray<SimulatedOperandStack*> (len + 1);
for (int i = 0; i <= len; ++i) {
_stacks->push(NULL);
}
// Initialize stack a bci 0.
_stacks->at_put(0, new SimulatedOperandStack());
// And initialize the start of all exception handlers.
if (const_method->has_exception_handler()) {
ExceptionTableElement *et = const_method->exception_table_start();
for (int i = 0; i < const_method->exception_table_length(); ++i) {
u2 index = et[i].handler_pc;
if (_stacks->at(index) == NULL) {
_stacks->at_put(index, new SimulatedOperandStack());
_stacks->at(index)->push(index, T_OBJECT);
}
}
}
// Do this until each bytecode has a stack or we haven't
// added a new stack in one iteration.
while (!_all_processed && _added_one) {
_all_processed = true;
_added_one = false;
for (int i = 0; i < len; ) {
// Analyse bytecode i. Step by size of the analyzed bytecode to next bytecode.
i += do_instruction(i);
// If we want the data only for a certain bci, we can possibly end early.
if ((bci == i) && (_stacks->at(i) != NULL)) {
_all_processed = true;
break;
}
if (_nr_of_entries > _max_entries) {
return;
}
}
}
}
ExceptionMessageBuilder::~ExceptionMessageBuilder() {
if (_stacks != NULL) {
for (int i = 0; i < _stacks->length(); ++i) {
delete _stacks->at(i);
}
}
}
void ExceptionMessageBuilder::merge(int bci, SimulatedOperandStack* stack) {
assert(stack != _stacks->at(bci), "Cannot merge itself");
if (_stacks->at(bci) != NULL) {
stack->merge(*_stacks->at(bci));
} else {
// Got a new stack, so count the entries.
_nr_of_entries += stack->get_size();
}
// Replace the stack at this bci with a copy of our new merged stack.
delete _stacks->at(bci);
_stacks->at_put(bci, new SimulatedOperandStack(*stack));
}
int ExceptionMessageBuilder::do_instruction(int bci) {
ConstMethod* const_method = _method->constMethod();
address code_base = _method->constMethod()->code_base();
// We use the java code, since we don't want to cope with all the fast variants.
int len = Bytecodes::java_length_at(_method, code_base + bci);
// If we have no stack for this bci, we cannot process the bytecode now.
if (_stacks->at(bci) == NULL) {
_all_processed = false;
return len;
}
// Make a local copy of the stack for this bci to work on.
SimulatedOperandStack* stack = new SimulatedOperandStack(*_stacks->at(bci));
// dest_bci is != -1 if we branch.
int dest_bci = -1;
// This is for table and lookup switch.
static const int initial_length = 2;
GrowableArray<int> dests(initial_length);
bool flow_ended = false;
// Get the bytecode.
bool is_wide = false;
Bytecodes::Code raw_code = Bytecodes::code_at(_method, code_base + bci);
Bytecodes::Code code = Bytecodes::java_code_at(_method, code_base + bci);
int pos = bci + 1;
if (code == Bytecodes::_wide) {
is_wide = true;
code = Bytecodes::java_code_at(_method, code_base + bci + 1);
pos += 1;
}
// Now simulate the action of each bytecode.
switch (code) {
case Bytecodes::_nop:
case Bytecodes::_aconst_null:
case Bytecodes::_iconst_m1:
case Bytecodes::_iconst_0:
case Bytecodes::_iconst_1:
case Bytecodes::_iconst_2:
case Bytecodes::_iconst_3:
case Bytecodes::_iconst_4:
case Bytecodes::_iconst_5:
case Bytecodes::_lconst_0:
case Bytecodes::_lconst_1:
case Bytecodes::_fconst_0:
case Bytecodes::_fconst_1:
case Bytecodes::_fconst_2:
case Bytecodes::_dconst_0:
case Bytecodes::_dconst_1:
case Bytecodes::_bipush:
case Bytecodes::_sipush:
case Bytecodes::_iload:
case Bytecodes::_lload:
case Bytecodes::_fload:
case Bytecodes::_dload:
case Bytecodes::_aload:
case Bytecodes::_iload_0:
case Bytecodes::_iload_1:
case Bytecodes::_iload_2:
case Bytecodes::_iload_3:
case Bytecodes::_lload_0:
case Bytecodes::_lload_1:
case Bytecodes::_lload_2:
case Bytecodes::_lload_3:
case Bytecodes::_fload_0:
case Bytecodes::_fload_1:
case Bytecodes::_fload_2:
case Bytecodes::_fload_3:
case Bytecodes::_dload_0:
case Bytecodes::_dload_1:
case Bytecodes::_dload_2:
case Bytecodes::_dload_3:
case Bytecodes::_aload_0:
case Bytecodes::_aload_1:
case Bytecodes::_aload_2:
case Bytecodes::_aload_3:
case Bytecodes::_iinc:
case Bytecodes::_new:
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_ldc:
case Bytecodes::_ldc_w:
case Bytecodes::_ldc2_w: {
int cp_index;
ConstantPool* cp = _method->constants();
if (code == Bytecodes::_ldc) {
cp_index = *(uint8_t*) (code_base + pos);
if (raw_code == Bytecodes::_fast_aldc) {
cp_index = cp->object_to_cp_index(cp_index);
}
} else {
if (raw_code == Bytecodes::_fast_aldc_w) {
cp_index = Bytes::get_native_u2(code_base + pos);
cp_index = cp->object_to_cp_index(cp_index);
}
else {
cp_index = Bytes::get_Java_u2(code_base + pos);
}
}
constantTag tag = cp->tag_at(cp_index);
if (tag.is_klass() || tag.is_unresolved_klass() ||
tag.is_method() || tag.is_interface_method() ||
tag.is_field() || tag.is_string()) {
stack->push(bci, T_OBJECT);
} else if (tag.is_int()) {
stack->push(bci, T_INT);
} else if (tag.is_long()) {
stack->push(bci, T_LONG);
} else if (tag.is_float()) {
stack->push(bci, T_FLOAT);
} else if (tag.is_double()) {
stack->push(bci, T_DOUBLE);
} else {
assert(false, "Unexpected tag");
}
break;
}
case Bytecodes::_iaload:
case Bytecodes::_faload:
case Bytecodes::_aaload:
case Bytecodes::_baload:
case Bytecodes::_caload:
case Bytecodes::_saload:
case Bytecodes::_laload:
case Bytecodes::_daload:
stack->pop(2);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_istore:
case Bytecodes::_lstore:
case Bytecodes::_fstore:
case Bytecodes::_dstore:
case Bytecodes::_astore:
int index;
if (is_wide) {
index = Bytes::get_Java_u2(code_base + bci + 2);
} else {
index = *(uint8_t*) (code_base + bci + 1);
}
stack->set_local_slot_written(index);
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_istore_0:
case Bytecodes::_lstore_0:
case Bytecodes::_fstore_0:
case Bytecodes::_dstore_0:
case Bytecodes::_astore_0:
stack->set_local_slot_written(0);
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_istore_1:
case Bytecodes::_fstore_1:
case Bytecodes::_lstore_1:
case Bytecodes::_dstore_1:
case Bytecodes::_astore_1:
stack->set_local_slot_written(1);
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_istore_2:
case Bytecodes::_lstore_2:
case Bytecodes::_fstore_2:
case Bytecodes::_dstore_2:
case Bytecodes::_astore_2:
stack->set_local_slot_written(2);
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_istore_3:
case Bytecodes::_lstore_3:
case Bytecodes::_fstore_3:
case Bytecodes::_dstore_3:
case Bytecodes::_astore_3:
stack->set_local_slot_written(3);
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_iastore:
case Bytecodes::_lastore:
case Bytecodes::_fastore:
case Bytecodes::_dastore:
case Bytecodes::_aastore:
case Bytecodes::_bastore:
case Bytecodes::_castore:
case Bytecodes::_sastore:
case Bytecodes::_pop:
case Bytecodes::_pop2:
case Bytecodes::_monitorenter:
case Bytecodes::_monitorexit:
case Bytecodes::_breakpoint:
stack->pop(-Bytecodes::depth(code));
break;
case Bytecodes::_dup:
stack->push_raw(stack->get_slot_data(0));
break;
case Bytecodes::_dup_x1: {
StackSlotAnalysisData top1 = stack->get_slot_data(0);
StackSlotAnalysisData top2 = stack->get_slot_data(1);
stack->pop(2);
stack->push_raw(top1);
stack->push_raw(top2);
stack->push_raw(top1);
break;
}
case Bytecodes::_dup_x2: {
StackSlotAnalysisData top1 = stack->get_slot_data(0);
StackSlotAnalysisData top2 = stack->get_slot_data(1);
StackSlotAnalysisData top3 = stack->get_slot_data(2);
stack->pop(3);
stack->push_raw(top1);
stack->push_raw(top3);
stack->push_raw(top2);
stack->push_raw(top1);
break;
}
case Bytecodes::_dup2:
stack->push_raw(stack->get_slot_data(1));
// The former '0' entry is now at '1'.
stack->push_raw(stack->get_slot_data(1));
break;
case Bytecodes::_dup2_x1: {
StackSlotAnalysisData top1 = stack->get_slot_data(0);
StackSlotAnalysisData top2 = stack->get_slot_data(1);
StackSlotAnalysisData top3 = stack->get_slot_data(2);
stack->pop(3);
stack->push_raw(top2);
stack->push_raw(top1);
stack->push_raw(top3);
stack->push_raw(top2);
stack->push_raw(top1);
break;
}
case Bytecodes::_dup2_x2: {
StackSlotAnalysisData top1 = stack->get_slot_data(0);
StackSlotAnalysisData top2 = stack->get_slot_data(1);
StackSlotAnalysisData top3 = stack->get_slot_data(2);
StackSlotAnalysisData top4 = stack->get_slot_data(3);
stack->pop(4);
stack->push_raw(top2);
stack->push_raw(top1);
stack->push_raw(top4);
stack->push_raw(top3);
stack->push_raw(top2);
stack->push_raw(top1);
break;
}
case Bytecodes::_swap: {
StackSlotAnalysisData top1 = stack->get_slot_data(0);
StackSlotAnalysisData top2 = stack->get_slot_data(1);
stack->pop(2);
stack->push(top1);
stack->push(top2);
break;
}
case Bytecodes::_iadd:
case Bytecodes::_ladd:
case Bytecodes::_fadd:
case Bytecodes::_dadd:
case Bytecodes::_isub:
case Bytecodes::_lsub:
case Bytecodes::_fsub:
case Bytecodes::_dsub:
case Bytecodes::_imul:
case Bytecodes::_lmul:
case Bytecodes::_fmul:
case Bytecodes::_dmul:
case Bytecodes::_idiv:
case Bytecodes::_ldiv:
case Bytecodes::_fdiv:
case Bytecodes::_ddiv:
case Bytecodes::_irem:
case Bytecodes::_lrem:
case Bytecodes::_frem:
case Bytecodes::_drem:
case Bytecodes::_iand:
case Bytecodes::_land:
case Bytecodes::_ior:
case Bytecodes::_lor:
case Bytecodes::_ixor:
case Bytecodes::_lxor:
stack->pop(2 * type2size[Bytecodes::result_type(code)]);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_ineg:
case Bytecodes::_lneg:
case Bytecodes::_fneg:
case Bytecodes::_dneg:
stack->pop(type2size[Bytecodes::result_type(code)]);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_ishl:
case Bytecodes::_lshl:
case Bytecodes::_ishr:
case Bytecodes::_lshr:
case Bytecodes::_iushr:
case Bytecodes::_lushr:
stack->pop(1 + type2size[Bytecodes::result_type(code)]);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_i2l:
case Bytecodes::_i2f:
case Bytecodes::_i2d:
case Bytecodes::_f2i:
case Bytecodes::_f2l:
case Bytecodes::_f2d:
case Bytecodes::_i2b:
case Bytecodes::_i2c:
case Bytecodes::_i2s:
stack->pop(1);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_l2i:
case Bytecodes::_l2f:
case Bytecodes::_l2d:
case Bytecodes::_d2i:
case Bytecodes::_d2l:
case Bytecodes::_d2f:
stack->pop(2);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_lcmp:
case Bytecodes::_fcmpl:
case Bytecodes::_fcmpg:
case Bytecodes::_dcmpl:
case Bytecodes::_dcmpg:
stack->pop(1 - Bytecodes::depth(code));
stack->push(bci, T_INT);
break;
case Bytecodes::_ifeq:
case Bytecodes::_ifne:
case Bytecodes::_iflt:
case Bytecodes::_ifge:
case Bytecodes::_ifgt:
case Bytecodes::_ifle:
case Bytecodes::_if_icmpeq:
case Bytecodes::_if_icmpne:
case Bytecodes::_if_icmplt:
case Bytecodes::_if_icmpge:
case Bytecodes::_if_icmpgt:
case Bytecodes::_if_icmple:
case Bytecodes::_if_acmpeq:
case Bytecodes::_if_acmpne:
case Bytecodes::_ifnull:
case Bytecodes::_ifnonnull:
stack->pop(-Bytecodes::depth(code));
dest_bci = bci + (int16_t) Bytes::get_Java_u2(code_base + pos);
break;
case Bytecodes::_jsr:
// NOTE: Bytecodes has wrong depth for jsr.
stack->push(bci, T_ADDRESS);
dest_bci = bci + (int16_t) Bytes::get_Java_u2(code_base + pos);
flow_ended = true;
break;
case Bytecodes::_jsr_w: {
// NOTE: Bytecodes has wrong depth for jsr.
stack->push(bci, T_ADDRESS);
dest_bci = bci + (int32_t) Bytes::get_Java_u4(code_base + pos);
flow_ended = true;
break;
}
case Bytecodes::_ret:
// We don't track local variables, so we cannot know were we
// return. This makes the stacks imprecise, but we have to
// live with that.
flow_ended = true;
break;
case Bytecodes::_tableswitch: {
stack->pop(1);
pos = (pos + 3) & ~3;
dest_bci = bci + (int32_t) Bytes::get_Java_u4(code_base + pos);
int low = (int32_t) Bytes::get_Java_u4(code_base + pos + 4);
int high = (int32_t) Bytes::get_Java_u4(code_base + pos + 8);
for (int64_t i = low; i <= high; ++i) {
dests.push(bci + (int32_t) Bytes::get_Java_u4(code_base + pos + 12 + 4 * (i - low)));
}
break;
}
case Bytecodes::_lookupswitch: {
stack->pop(1);
pos = (pos + 3) & ~3;
dest_bci = bci + (int32_t) Bytes::get_Java_u4(code_base + pos);
int nr_of_dests = (int32_t) Bytes::get_Java_u4(code_base + pos + 4);
for (int i = 0; i < nr_of_dests; ++i) {
dests.push(bci + (int32_t) Bytes::get_Java_u4(code_base + pos + 12 + 8 * i));
}
break;
}
case Bytecodes::_ireturn:
case Bytecodes::_lreturn:
case Bytecodes::_freturn:
case Bytecodes::_dreturn:
case Bytecodes::_areturn:
case Bytecodes::_return:
case Bytecodes::_athrow:
stack->pop(-Bytecodes::depth(code));
flow_ended = true;
break;
case Bytecodes::_getstatic:
case Bytecodes::_getfield: {
// Find out the type of the field accessed.
int cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
ConstantPool* cp = _method->constants();
int name_and_type_index = cp->name_and_type_ref_index_at(cp_index);
int type_index = cp->signature_ref_index_at(name_and_type_index);
Symbol* signature = cp->symbol_at(type_index);
// Simulate the bytecode: pop the address, push the 'value' loaded
// from the field.
stack->pop(1 - Bytecodes::depth(code));
stack->push(bci, char2type((char) signature->char_at(0)));
break;
}
case Bytecodes::_putstatic:
case Bytecodes::_putfield: {
int cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
ConstantPool* cp = _method->constants();
int name_and_type_index = cp->name_and_type_ref_index_at(cp_index);
int type_index = cp->signature_ref_index_at(name_and_type_index);
Symbol* signature = cp->symbol_at(type_index);
ResultTypeFinder result_type(signature);
stack->pop(type2size[char2type((char) signature->char_at(0))] - Bytecodes::depth(code) - 1);
break;
}
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
case Bytecodes::_invokeinterface:
case Bytecodes::_invokedynamic: {
ConstantPool* cp = _method->constants();
int cp_index;
if (code == Bytecodes::_invokedynamic) {
cp_index = ((int) Bytes::get_native_u4(code_base + pos));
} else {
cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
}
int name_and_type_index = cp->name_and_type_ref_index_at(cp_index);
int type_index = cp->signature_ref_index_at(name_and_type_index);
Symbol* signature = cp->symbol_at(type_index);
if ((code != Bytecodes::_invokestatic) && (code != Bytecodes::_invokedynamic)) {
// Pop receiver.
stack->pop(1);
}
stack->pop(ArgumentSizeComputer(signature).size());
ResultTypeFinder result_type(signature);
stack->push(bci, result_type.type());
break;
}
case Bytecodes::_newarray:
case Bytecodes::_anewarray:
case Bytecodes::_instanceof:
stack->pop(1);
stack->push(bci, Bytecodes::result_type(code));
break;
case Bytecodes::_arraylength:
// The return type of arraylength is wrong in the bytecodes table (T_VOID).
stack->pop(1);
stack->push(bci, T_INT);
break;
case Bytecodes::_checkcast:
break;
case Bytecodes::_multianewarray:
stack->pop(*(uint8_t*) (code_base + pos + 2));
stack->push(bci, T_OBJECT);
break;
case Bytecodes::_goto:
stack->pop(-Bytecodes::depth(code));
dest_bci = bci + (int16_t) Bytes::get_Java_u2(code_base + pos);
flow_ended = true;
break;
case Bytecodes::_goto_w:
stack->pop(-Bytecodes::depth(code));
dest_bci = bci + (int32_t) Bytes::get_Java_u4(code_base + pos);
flow_ended = true;
break;
default:
// Allow at least the bcis which have stack info to work.
_all_processed = false;
_added_one = false;
delete stack;
return len;
}
// Put new stack to the next instruction, if we might reach it from
// this bci.
if (!flow_ended) {
if (_stacks->at(bci + len) == NULL) {
_added_one = true;
}
merge(bci + len, stack);
}
// Put the stack to the branch target too.
if (dest_bci != -1) {
if (_stacks->at(dest_bci) == NULL) {
_added_one = true;
}
merge(dest_bci, stack);
}
// If we have more than one branch target, process these too.
for (int64_t i = 0; i < dests.length(); ++i) {
if (_stacks->at(dests.at(i)) == NULL) {
_added_one = true;
}
merge(dests.at(i), stack);
}
delete stack;
return len;
}
#define INVALID_BYTECODE_ENCOUNTERED -1
#define NPE_EXPLICIT_CONSTRUCTED -2
int ExceptionMessageBuilder::get_NPE_null_slot(int bci) {
// Get the bytecode.
address code_base = _method->constMethod()->code_base();
Bytecodes::Code code = Bytecodes::java_code_at(_method, code_base + bci);
int pos = bci + 1; // Position of argument of the bytecode.
if (code == Bytecodes::_wide) {
code = Bytecodes::java_code_at(_method, code_base + bci + 1);
pos += 1;
}
switch (code) {
case Bytecodes::_getfield:
case Bytecodes::_arraylength:
case Bytecodes::_athrow:
case Bytecodes::_monitorenter:
case Bytecodes::_monitorexit:
return 0;
case Bytecodes::_iaload:
case Bytecodes::_faload:
case Bytecodes::_aaload:
case Bytecodes::_baload:
case Bytecodes::_caload:
case Bytecodes::_saload:
case Bytecodes::_laload:
case Bytecodes::_daload:
return 1;
case Bytecodes::_iastore:
case Bytecodes::_fastore:
case Bytecodes::_aastore:
case Bytecodes::_bastore:
case Bytecodes::_castore:
case Bytecodes::_sastore:
return 2;
case Bytecodes::_lastore:
case Bytecodes::_dastore:
return 3;
case Bytecodes::_putfield: {
int cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
ConstantPool* cp = _method->constants();
int name_and_type_index = cp->name_and_type_ref_index_at(cp_index);
int type_index = cp->signature_ref_index_at(name_and_type_index);
Symbol* signature = cp->symbol_at(type_index);
return type2size[char2type((char) signature->char_at(0))];
}
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokeinterface: {
int cp_index = Bytes::get_native_u2(code_base+ pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
ConstantPool* cp = _method->constants();
int name_and_type_index = cp->name_and_type_ref_index_at(cp_index);
int name_index = cp->name_ref_index_at(name_and_type_index);
Symbol* name = cp->symbol_at(name_index);
// Assume the the call of a constructor can never cause a NullPointerException
// (which is true in Java). This is mainly used to avoid generating wrong
// messages for NullPointerExceptions created explicitly by new in Java code.
if (name != vmSymbols::object_initializer_name()) {
int type_index = cp->signature_ref_index_at(name_and_type_index);
Symbol* signature = cp->symbol_at(type_index);
// The 'this' parameter was null. Return the slot of it.
return ArgumentSizeComputer(signature).size();
} else {
return NPE_EXPLICIT_CONSTRUCTED;
}
}
default:
break;
}
return INVALID_BYTECODE_ENCOUNTERED;
}
bool ExceptionMessageBuilder::print_NPE_cause(outputStream* os, int bci, int slot) {
if (print_NPE_cause0(os, bci, slot, _max_cause_detail, false, " because \"")) {
os->print("\" is null");
return true;
}
return false;
}
// Recursively print what was null.
//
// Go to the bytecode that pushed slot 'slot' on the operand stack
// at bytecode 'bci'. Compute a message for that bytecode. If
// necessary (array, field), recur further.
// At most do max_detail recursions.
// Prefix is used to print a proper beginning of the whole
// sentence.
// inner_expr is used to omit some text, like 'static' in
// inner expressions like array subscripts.
//
// Returns true if something was printed.
//
bool ExceptionMessageBuilder::print_NPE_cause0(outputStream* os, int bci, int slot,
int max_detail,
bool inner_expr, const char *prefix) {
assert(bci >= 0, "BCI too low");
assert(bci < get_size(), "BCI too large");
if (max_detail <= 0) {
return false;
}
if (_stacks->at(bci) == NULL) {
return false;
}
SimulatedOperandStack* stack = _stacks->at(bci);
assert(slot >= 0, "Slot nr. too low");
assert(slot < stack->get_size(), "Slot nr. too large");
StackSlotAnalysisData slotData = stack->get_slot_data(slot);
if (!slotData.has_bci()) {
return false;
}
// Get the bytecode.
unsigned int source_bci = slotData.get_bci();
address code_base = _method->constMethod()->code_base();
Bytecodes::Code code = Bytecodes::java_code_at(_method, code_base + source_bci);
bool is_wide = false;
int pos = source_bci + 1;
if (code == Bytecodes::_wide) {
is_wide = true;
code = Bytecodes::java_code_at(_method, code_base + source_bci + 1);
pos += 1;
}
if (max_detail == _max_cause_detail &&
prefix != NULL &&
code != Bytecodes::_invokevirtual &&
code != Bytecodes::_invokespecial &&
code != Bytecodes::_invokestatic &&
code != Bytecodes::_invokeinterface) {
os->print("%s", prefix);
}
switch (code) {
case Bytecodes::_iload_0:
case Bytecodes::_aload_0:
print_local_var(os, source_bci, _method, 0, !stack->local_slot_was_written(0));
return true;
case Bytecodes::_iload_1:
case Bytecodes::_aload_1:
print_local_var(os, source_bci, _method, 1, !stack->local_slot_was_written(1));
return true;
case Bytecodes::_iload_2:
case Bytecodes::_aload_2:
print_local_var(os, source_bci, _method, 2, !stack->local_slot_was_written(2));
return true;
case Bytecodes::_iload_3:
case Bytecodes::_aload_3:
print_local_var(os, source_bci, _method, 3, !stack->local_slot_was_written(3));
return true;
case Bytecodes::_iload:
case Bytecodes::_aload: {
int index;
if (is_wide) {
index = Bytes::get_Java_u2(code_base + source_bci + 2);
} else {
index = *(uint8_t*) (code_base + source_bci + 1);
}
print_local_var(os, source_bci, _method, index, !stack->local_slot_was_written(index));
return true;
}
case Bytecodes::_aconst_null:
os->print("null");
return true;
case Bytecodes::_iconst_m1:
os->print("-1");
return true;
case Bytecodes::_iconst_0:
os->print("0");
return true;
case Bytecodes::_iconst_1:
os->print("1");
return true;
case Bytecodes::_iconst_2:
os->print("2");
return true;
case Bytecodes::_iconst_3:
os->print("3");
return true;
case Bytecodes::_iconst_4:
os->print("4");
return true;
case Bytecodes::_iconst_5:
os->print("5");
return true;
case Bytecodes::_bipush: {
jbyte con = *(jbyte*) (code_base + source_bci + 1);
os->print("%d", con);
return true;
}
case Bytecodes::_sipush: {
u2 con = Bytes::get_Java_u2(code_base + source_bci + 1);
os->print("%d", con);
return true;
}
case Bytecodes::_iaload:
case Bytecodes::_aaload: {
// Print the 'name' of the array. Go back to the bytecode that
// pushed the array reference on the operand stack.
if (!print_NPE_cause0(os, source_bci, 1, max_detail - 1, inner_expr)) {
// Returned false. Max recursion depth was reached. Print dummy.
os->print("<array>");
}
os->print("[");
// Print the index expression. Go back to the bytecode that
// pushed the index on the operand stack.
// inner_expr == true so we don't print unwanted strings
// as "The return value of'". And don't decrement max_detail so we always
// get a value here and only cancel out on the dereference.
if (!print_NPE_cause0(os, source_bci, 0, max_detail, true)) {
// Returned false. We don't print complex array index expressions. Print placeholder.
os->print("...");
}
os->print("]");
return true;
}
case Bytecodes::_getstatic: {
int cp_index = Bytes::get_native_u2(code_base + pos) + ConstantPool::CPCACHE_INDEX_TAG;
print_field_and_class(os, _method, cp_index);
return true;
}
case Bytecodes::_getfield: {
// Print the sender. Go back to the bytecode that
// pushed the sender on the operand stack.
if (print_NPE_cause0(os, source_bci, 0, max_detail - 1, inner_expr)) {
os->print(".");
}
int cp_index = Bytes::get_native_u2(code_base + pos) + ConstantPool::CPCACHE_INDEX_TAG;
os->print("%s", get_field_name(_method, cp_index));
return true;
}
case Bytecodes::_invokevirtual:
case Bytecodes::_invokespecial:
case Bytecodes::_invokestatic:
case Bytecodes::_invokeinterface: {
int cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
if (max_detail == _max_cause_detail && !inner_expr) {
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