--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/interpreter/bytecodeUtils.cpp Mon Oct 14 11:36:17 2019 +0200
@@ -0,0 +1,1481 @@
+/*
+ * 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) {
+ os->print(" because the return value of \"");
+ }
+ print_method_name(os, _method, cp_index);
+ return true;
+ }
+
+ default: break;
+ }
+ return false;
+}
+
+void ExceptionMessageBuilder::print_NPE_failed_action(outputStream *os, 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;
+ if (code == Bytecodes::_wide) {
+ code = Bytecodes::java_code_at(_method, code_base + bci + 1);
+ pos += 1;
+ }
+
+ switch (code) {
+ case Bytecodes::_iaload:
+ os->print("Cannot load from int array"); break;
+ case Bytecodes::_faload:
+ os->print("Cannot load from float array"); break;
+ case Bytecodes::_aaload:
+ os->print("Cannot load from object array"); break;
+ case Bytecodes::_baload:
+ os->print("Cannot load from byte/boolean array"); break;
+ case Bytecodes::_caload:
+ os->print("Cannot load from char array"); break;
+ case Bytecodes::_saload:
+ os->print("Cannot load from short array"); break;
+ case Bytecodes::_laload:
+ os->print("Cannot load from long array"); break;
+ case Bytecodes::_daload:
+ os->print("Cannot load from double array"); break;
+
+ case Bytecodes::_iastore:
+ os->print("Cannot store to int array"); break;
+ case Bytecodes::_fastore:
+ os->print("Cannot store to float array"); break;
+ case Bytecodes::_aastore:
+ os->print("Cannot store to object array"); break;
+ case Bytecodes::_bastore:
+ os->print("Cannot store to byte/boolean array"); break;
+ case Bytecodes::_castore:
+ os->print("Cannot store to char array"); break;
+ case Bytecodes::_sastore:
+ os->print("Cannot store to short array"); break;
+ case Bytecodes::_lastore:
+ os->print("Cannot store to long array"); break;
+ case Bytecodes::_dastore:
+ os->print("Cannot store to double array"); break;
+
+ case Bytecodes::_arraylength:
+ os->print("Cannot read the array length"); break;
+ case Bytecodes::_athrow:
+ os->print("Cannot throw exception"); break;
+ case Bytecodes::_monitorenter:
+ os->print("Cannot enter synchronized block"); break;
+ case Bytecodes::_monitorexit:
+ os->print("Cannot exit synchronized block"); break;
+ case Bytecodes::_getfield: {
+ 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);
+ os->print("Cannot read field \"%s\"", name->as_C_string());
+ } break;
+ case Bytecodes::_putfield: {
+ int cp_index = Bytes::get_native_u2(code_base + pos) DEBUG_ONLY(+ ConstantPool::CPCACHE_INDEX_TAG);
+ os->print("Cannot assign field \"%s\"", get_field_name(_method, cp_index));
+ } break;
+ 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);
+ os->print("Cannot invoke \"");
+ print_method_name(os, _method, cp_index);
+ os->print("\"");
+ } break;
+
+ default:
+ assert(0, "We should have checked this bytecode in get_NPE_null_slot().");
+ break;
+ }
+}
+
+// Main API
+bool BytecodeUtils::get_NPE_message_at(outputStream* ss, Method* method, int bci) {
+
+ NoSafepointVerifier _nsv; // Cannot use this object over a safepoint.
+
+ // If this NPE was created via reflection, we have no real NPE.
+ if (method->method_holder() ==
+ SystemDictionary::reflect_NativeConstructorAccessorImpl_klass()) {
+ return false;
+ }
+
+ // Analyse the bytecodes.
+ ResourceMark rm;
+ ExceptionMessageBuilder emb(method, bci);
+
+ // The slot of the operand stack that contains the null reference.
+ // Also checks for NPE explicitly constructed and returns NPE_EXPLICIT_CONSTRUCTED.
+ int slot = emb.get_NPE_null_slot(bci);
+
+ // Build the message.
+ if (slot == NPE_EXPLICIT_CONSTRUCTED) {
+ // We don't want to print a message.
+ return false;
+ } else if (slot == INVALID_BYTECODE_ENCOUNTERED) {
+ // We encountered a bytecode that does not dereference a reference.
+ DEBUG_ONLY(ss->print("There cannot be a NullPointerException at bci %d of method %s",
+ bci, method->external_name()));
+ NOT_DEBUG(return false);
+ } else {
+ // Print string describing which action (bytecode) could not be
+ // performed because of the null reference.
+ emb.print_NPE_failed_action(ss, bci);
+ // Print a description of what is null.
+ if (!emb.print_NPE_cause(ss, bci, slot)) {
+ // Nothing was printed. End the sentence without the 'because'
+ // subordinate sentence.
+ }
+ }
+ return true;
+}