/*
* Copyright 2000-2017 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jetbrains.java.decompiler.modules.decompiler;
import org.jetbrains.java.decompiler.code.CodeConstants;
import org.jetbrains.java.decompiler.modules.decompiler.exps.*;
import org.jetbrains.java.decompiler.modules.decompiler.stats.IfStatement;
import org.jetbrains.java.decompiler.modules.decompiler.stats.SequenceStatement;
import org.jetbrains.java.decompiler.modules.decompiler.stats.Statement;
import org.jetbrains.java.decompiler.struct.StructMethod;
import org.jetbrains.java.decompiler.struct.attr.StructAnnotationAttribute;
import org.jetbrains.java.decompiler.struct.attr.StructAnnotationParameterAttribute;
import org.jetbrains.java.decompiler.struct.attr.StructGeneralAttribute;
import org.jetbrains.java.decompiler.struct.gen.MethodDescriptor;
import java.util.List;
public class IdeaNotNullHelper {
public static boolean removeHardcodedChecks(Statement root, StructMethod mt) {
boolean checks_removed = false;
// parameter @NotNull annotations
while (findAndRemoveParameterCheck(root, mt)) { // iterate until nothing found. Each invocation removes one parameter check.
checks_removed = true;
}
// method @NotNull annotation
while (findAndRemoveReturnCheck(root, mt)) { // iterate until nothing found. Each invocation handles one method exit check.
checks_removed = true;
}
return checks_removed;
}
private static boolean findAndRemoveParameterCheck(Statement stat, StructMethod mt) {
Statement st = stat.getFirst();
while (st.type == Statement.TYPE_SEQUENCE) {
st = st.getFirst();
}
if (st.type == Statement.TYPE_IF) {
IfStatement ifstat = (IfStatement)st;
Statement ifbranch = ifstat.getIfstat();
Exprent if_condition = ifstat.getHeadexprent().getCondition();
boolean is_notnull_check = false;
// TODO: FUNCTION_NE also possible if reversed order (in theory)
if (ifbranch != null &&
if_condition.type == Exprent.EXPRENT_FUNCTION &&
((FunctionExprent)if_condition).getFuncType() == FunctionExprent.FUNCTION_EQ &&
ifbranch.type == Statement.TYPE_BASICBLOCK &&
ifbranch.getExprents().size() == 1 &&
ifbranch.getExprents().get(0).type == Exprent.EXPRENT_EXIT) {
FunctionExprent func = (FunctionExprent)if_condition;
Exprent first_param = func.getLstOperands().get(0);
Exprent second_param = func.getLstOperands().get(1);
if (second_param.type == Exprent.EXPRENT_CONST &&
second_param.getExprType().type == CodeConstants.TYPE_NULL) { // TODO: reversed parameter order
if (first_param.type == Exprent.EXPRENT_VAR) {
VarExprent var = (VarExprent)first_param;
boolean thisvar = !mt.hasModifier(CodeConstants.ACC_STATIC);
MethodDescriptor md = MethodDescriptor.parseDescriptor(mt.getDescriptor());
// parameter annotations
StructAnnotationParameterAttribute param_annotations =
(StructAnnotationParameterAttribute)mt.getAttribute(StructGeneralAttribute.ATTRIBUTE_RUNTIME_INVISIBLE_PARAMETER_ANNOTATIONS);
if (param_annotations != null) {
List<List<AnnotationExprent>> param_annotations_lists = param_annotations.getParamAnnotations();
int method_param_number = md.params.length;
int index = thisvar ? 1 : 0;
for (int i = 0; i < method_param_number; i++) {
if (index == var.getIndex()) {
if (param_annotations_lists.size() >= method_param_number - i) {
int shift = method_param_number -
param_annotations_lists
.size(); // NOTE: workaround for compiler bug, count annotations starting with the last parameter
List<AnnotationExprent> annotations = param_annotations_lists.get(i - shift);
for (AnnotationExprent ann : annotations) {
if (ann.getClassName().equals("org/jetbrains/annotations/NotNull")) {
is_notnull_check = true;
}
}
}
break;
}
index += md.params[i].stackSize;
}
}
}
}
}
if (!is_notnull_check) {
return false;
}
removeParameterCheck(stat, mt);
return true;
}
return false;
}
private static void removeParameterCheck(Statement stat, StructMethod mt) {
Statement st = stat.getFirst();
while (st.type == Statement.TYPE_SEQUENCE) {
st = st.getFirst();
}
IfStatement ifstat = (IfStatement)st;
if (ifstat.getElsestat() == null) { // if
// TODO:
}
else { // if - else
StatEdge ifedge = ifstat.getIfEdge();
StatEdge elseedge = ifstat.getElseEdge();
Statement ifbranch = ifstat.getIfstat();
Statement elsebranch = ifstat.getElsestat();
ifstat.getFirst().removeSuccessor(ifedge);
ifstat.getFirst().removeSuccessor(elseedge);
ifstat.getStats().removeWithKey(ifbranch.id);
ifstat.getStats().removeWithKey(elsebranch.id);
if (!ifbranch.getAllSuccessorEdges().isEmpty()) {
ifbranch.removeSuccessor(ifbranch.getAllSuccessorEdges().get(0));
}
ifstat.getParent().replaceStatement(ifstat, elsebranch);
ifstat.getParent().setAllParent();
}
}
private static boolean findAndRemoveReturnCheck(Statement stat, StructMethod mt) {
boolean is_notnull_check = false;
// method annotation, refers to the return value
StructAnnotationAttribute attr =
(StructAnnotationAttribute)mt.getAttribute(StructGeneralAttribute.ATTRIBUTE_RUNTIME_INVISIBLE_ANNOTATIONS);
if (attr != null) {
List<AnnotationExprent> annotations = attr.getAnnotations();
for (AnnotationExprent ann : annotations) {
if (ann.getClassName().equals("org/jetbrains/annotations/NotNull")) {
is_notnull_check = true;
}
}
}
if (is_notnull_check) {
return removeReturnCheck(stat, mt);
}
return false;
}
private static boolean removeReturnCheck(Statement stat, StructMethod mt) {
Statement parent = stat.getParent();
if (parent != null && parent.type == Statement.TYPE_IF && stat.type == Statement.TYPE_BASICBLOCK && stat.getExprents().size() == 1) {
Exprent exprent = stat.getExprents().get(0);
if (exprent.type == Exprent.EXPRENT_EXIT) {
ExitExprent exit_exprent = (ExitExprent)exprent;
if (exit_exprent.getExitType() == ExitExprent.EXIT_RETURN) {
Exprent exprent_value = exit_exprent.getValue();
//if(exprent_value.type == Exprent.EXPRENT_VAR) {
// VarExprent var_value = (VarExprent)exprent_value;
IfStatement ifparent = (IfStatement)parent;
Exprent if_condition = ifparent.getHeadexprent().getCondition();
if (ifparent.getElsestat() == stat && if_condition.type == Exprent.EXPRENT_FUNCTION &&
((FunctionExprent)if_condition).getFuncType() == FunctionExprent.FUNCTION_EQ) { // TODO: reversed order possible (in theory)
FunctionExprent func = (FunctionExprent)if_condition;
Exprent first_param = func.getLstOperands().get(0);
Exprent second_param = func.getLstOperands().get(1);
StatEdge ifedge = ifparent.getIfEdge();
StatEdge elseedge = ifparent.getElseEdge();
Statement ifbranch = ifparent.getIfstat();
Statement elsebranch = ifparent.getElsestat();
if (second_param.type == Exprent.EXPRENT_CONST &&
second_param.getExprType().type == CodeConstants.TYPE_NULL) { // TODO: reversed parameter order
//if(first_param.type == Exprent.EXPRENT_VAR && ((VarExprent)first_param).getIndex() == var_value.getIndex()) {
if (first_param.equals(exprent_value)) { // TODO: check for absence of side effects like method invocations etc.
if (ifbranch.type == Statement.TYPE_BASICBLOCK &&
ifbranch.getExprents().size() == 1 &&
// TODO: special check for IllegalStateException
ifbranch.getExprents().get(0).type == Exprent.EXPRENT_EXIT) {
ifparent.getFirst().removeSuccessor(ifedge);
ifparent.getFirst().removeSuccessor(elseedge);
ifparent.getStats().removeWithKey(ifbranch.id);
ifparent.getStats().removeWithKey(elsebranch.id);
if (!ifbranch.getAllSuccessorEdges().isEmpty()) {
ifbranch.removeSuccessor(ifbranch.getAllSuccessorEdges().get(0));
}
if (!ifparent.getFirst().getExprents().isEmpty()) {
elsebranch.getExprents().addAll(0, ifparent.getFirst().getExprents());
}
ifparent.getParent().replaceStatement(ifparent, elsebranch);
ifparent.getParent().setAllParent();
return true;
}
}
}
}
//}
}
}
}
else if (parent != null &&
parent.type == Statement.TYPE_SEQUENCE &&
stat.type == Statement.TYPE_BASICBLOCK &&
stat.getExprents().size() == 1) {
Exprent exprent = stat.getExprents().get(0);
if (exprent.type == Exprent.EXPRENT_EXIT) {
ExitExprent exit_exprent = (ExitExprent)exprent;
if (exit_exprent.getExitType() == ExitExprent.EXIT_RETURN) {
Exprent exprent_value = exit_exprent.getValue();
SequenceStatement sequence = (SequenceStatement)parent;
int sequence_stats_number = sequence.getStats().size();
if (sequence_stats_number > 1 &&
sequence.getStats().getLast() == stat &&
sequence.getStats().get(sequence_stats_number - 2).type == Statement.TYPE_IF) {
IfStatement ifstat = (IfStatement)sequence.getStats().get(sequence_stats_number - 2);
Exprent if_condition = ifstat.getHeadexprent().getCondition();
if (ifstat.iftype == IfStatement.IFTYPE_IF && if_condition.type == Exprent.EXPRENT_FUNCTION &&
((FunctionExprent)if_condition).getFuncType() == FunctionExprent.FUNCTION_EQ) { // TODO: reversed order possible (in theory)
FunctionExprent func = (FunctionExprent)if_condition;
Exprent first_param = func.getLstOperands().get(0);
Exprent second_param = func.getLstOperands().get(1);
Statement ifbranch = ifstat.getIfstat();
if (second_param.type == Exprent.EXPRENT_CONST &&
second_param.getExprType().type == CodeConstants.TYPE_NULL) { // TODO: reversed parameter order
if (first_param.equals(exprent_value)) { // TODO: check for absence of side effects like method invocations etc.
if (ifbranch.type == Statement.TYPE_BASICBLOCK &&
ifbranch.getExprents().size() == 1 &&
// TODO: special check for IllegalStateException
ifbranch.getExprents().get(0).type == Exprent.EXPRENT_EXIT) {
ifstat.removeSuccessor(ifstat.getAllSuccessorEdges().get(0)); // remove 'else' edge
if (!ifstat.getFirst().getExprents().isEmpty()) {
stat.getExprents().addAll(0, ifstat.getFirst().getExprents());
}
for (StatEdge edge : ifstat.getAllPredecessorEdges()) {
ifstat.removePredecessor(edge);
edge.getSource().changeEdgeNode(Statement.DIRECTION_FORWARD, edge, stat);
stat.addPredecessor(edge);
}
sequence.getStats().removeWithKey(ifstat.id);
sequence.setFirst(sequence.getStats().get(0));
return true;
}
}
}
}
}
}
}
}
for (Statement st : stat.getStats()) {
if (removeReturnCheck(st, mt)) {
return true;
}
}
return false;
}
}