diff options
Diffstat (limited to 'plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java')
| -rw-r--r-- | plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java | 750 |
1 files changed, 750 insertions, 0 deletions
diff --git a/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java new file mode 100644 index 000000000000..b1a955cfd528 --- /dev/null +++ b/plugins/java-decompiler/engine/src/org/jetbrains/java/decompiler/modules/decompiler/IfHelper.java @@ -0,0 +1,750 @@ +/* + * Copyright 2000-2014 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.modules.decompiler.exps.Exprent; +import org.jetbrains.java.decompiler.modules.decompiler.exps.FunctionExprent; +import org.jetbrains.java.decompiler.modules.decompiler.exps.IfExprent; +import org.jetbrains.java.decompiler.modules.decompiler.stats.IfStatement; +import org.jetbrains.java.decompiler.modules.decompiler.stats.RootStatement; +import org.jetbrains.java.decompiler.modules.decompiler.stats.SequenceStatement; +import org.jetbrains.java.decompiler.modules.decompiler.stats.Statement; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashSet; +import java.util.List; + + +public class IfHelper { + + + public static boolean mergeAllIfs(RootStatement root) { + + boolean res = mergeAllIfsRec(root, new HashSet<Integer>()); + + if (res) { + SequenceHelper.condenseSequences(root); + } + + return res; + } + + + private static boolean mergeAllIfsRec(Statement stat, HashSet<Integer> setReorderedIfs) { + + boolean res = false; + + if (stat.getExprents() == null) { + + while (true) { + + boolean changed = false; + + for (Statement st : stat.getStats()) { + + res |= mergeAllIfsRec(st, setReorderedIfs); + + // collapse composed if's + if (changed = mergeIfs(st, setReorderedIfs)) { + break; + } + } + + res |= changed; + + if (!changed) { + break; + } + } + } + + return res; + } + + + public static boolean mergeIfs(Statement statement, HashSet<Integer> setReorderedIfs) { + + if (statement.type != Statement.TYPE_IF && statement.type != Statement.TYPE_SEQUENCE) { + return false; + } + + boolean res = false; + + while (true) { + + boolean updated = false; + + List<Statement> lst = new ArrayList<Statement>(); + if (statement.type == Statement.TYPE_IF) { + lst.add(statement); + } + else { + lst.addAll(statement.getStats()); + } + + boolean stsingle = (lst.size() == 1); + + for (Statement stat : lst) { + + if (stat.type == Statement.TYPE_IF) { + IfNode rtnode = buildGraph((IfStatement)stat, stsingle); + + if (rtnode == null) { + continue; + } + + if (updated = collapseIfIf(rtnode)) { + break; + } + + if (!setReorderedIfs.contains(stat.id)) { + + if (updated = collapseIfElse(rtnode)) { + break; + } + + if (updated = collapseElse(rtnode)) { + break; + } + } + + if (updated = reorderIf((IfStatement)stat)) { + setReorderedIfs.add(stat.id); + break; + } + } + } + + if (!updated) { + break; + } + + res |= updated; + } + + return res; + } + + private static boolean collapseIfIf(IfNode rtnode) { + + if (rtnode.edgetypes.get(0) == 0) { + IfNode ifbranch = rtnode.succs.get(0); + if (ifbranch.succs.size() == 2) { + + // if-if branch + if (ifbranch.succs.get(1).value == rtnode.succs.get(1).value) { + + IfStatement ifparent = (IfStatement)rtnode.value; + IfStatement ifchild = (IfStatement)ifbranch.value; + Statement ifinner = ifbranch.succs.get(0).value; + + if (ifchild.getFirst().getExprents().isEmpty()) { + + ifparent.getFirst().removeSuccessor(ifparent.getIfEdge()); + ifchild.removeSuccessor(ifchild.getAllSuccessorEdges().get(0)); + ifparent.getStats().removeWithKey(ifchild.id); + + if (ifbranch.edgetypes.get(0).intValue() == 1) { // target null + + ifparent.setIfstat(null); + + StatEdge ifedge = ifchild.getIfEdge(); + + ifchild.getFirst().removeSuccessor(ifedge); + ifedge.setSource(ifparent.getFirst()); + + if (ifedge.closure == ifchild) { + ifedge.closure = null; + } + ifparent.getFirst().addSuccessor(ifedge); + + ifparent.setIfEdge(ifedge); + } + else { + ifchild.getFirst().removeSuccessor(ifchild.getIfEdge()); + + StatEdge ifedge = new StatEdge(StatEdge.TYPE_REGULAR, ifparent.getFirst(), ifinner); + ifparent.getFirst().addSuccessor(ifedge); + ifparent.setIfEdge(ifedge); + ifparent.setIfstat(ifinner); + + ifparent.getStats().addWithKey(ifinner, ifinner.id); + ifinner.setParent(ifparent); + + if (!ifinner.getAllSuccessorEdges().isEmpty()) { + StatEdge edge = ifinner.getAllSuccessorEdges().get(0); + if (edge.closure == ifchild) { + edge.closure = null; + } + } + } + + // merge if conditions + IfExprent statexpr = ifparent.getHeadexprent(); + + List<Exprent> lstOperands = new ArrayList<Exprent>(); + lstOperands.add(statexpr.getCondition()); + lstOperands.add(ifchild.getHeadexprent().getCondition()); + + statexpr.setCondition(new FunctionExprent(FunctionExprent.FUNCTION_CADD, lstOperands)); + + return true; + } + } + } + } + + return false; + } + + private static boolean collapseIfElse(IfNode rtnode) { + + if (rtnode.edgetypes.get(0).intValue() == 0) { + IfNode ifbranch = rtnode.succs.get(0); + if (ifbranch.succs.size() == 2) { + + // if-else branch + if (ifbranch.succs.get(0).value == rtnode.succs.get(1).value) { + + IfStatement ifparent = (IfStatement)rtnode.value; + IfStatement ifchild = (IfStatement)ifbranch.value; + + if (ifchild.getFirst().getExprents().isEmpty()) { + + ifparent.getFirst().removeSuccessor(ifparent.getIfEdge()); + ifchild.getFirst().removeSuccessor(ifchild.getIfEdge()); + ifparent.getStats().removeWithKey(ifchild.id); + + if (ifbranch.edgetypes.get(1).intValue() == 1 && + ifbranch.edgetypes.get(0).intValue() == 1) { // target null + + ifparent.setIfstat(null); + + StatEdge ifedge = ifchild.getAllSuccessorEdges().get(0); + + ifchild.removeSuccessor(ifedge); + ifedge.setSource(ifparent.getFirst()); + ifparent.getFirst().addSuccessor(ifedge); + + ifparent.setIfEdge(ifedge); + } + else { + throw new RuntimeException("inconsistent if structure!"); + } + + // merge if conditions + IfExprent statexpr = ifparent.getHeadexprent(); + + List<Exprent> lstOperands = new ArrayList<Exprent>(); + lstOperands.add(statexpr.getCondition()); + lstOperands.add(new FunctionExprent(FunctionExprent.FUNCTION_BOOLNOT, + Arrays.asList(new Exprent[]{ifchild.getHeadexprent().getCondition()}))); + statexpr.setCondition(new FunctionExprent(FunctionExprent.FUNCTION_CADD, lstOperands)); + + return true; + } + } + } + } + + return false; + } + + + private static boolean collapseElse(IfNode rtnode) { + + if (rtnode.edgetypes.get(1).intValue() == 0) { + IfNode elsebranch = rtnode.succs.get(1); + if (elsebranch.succs.size() == 2) { + + // else-if or else-else branch + int path = elsebranch.succs.get(1).value == rtnode.succs.get(0).value ? 2 : + (elsebranch.succs.get(0).value == rtnode.succs.get(0).value ? 1 : 0); + + if (path > 0) { + + IfStatement firstif = (IfStatement)rtnode.value; + IfStatement secondif = (IfStatement)elsebranch.value; + Statement parent = firstif.getParent(); + + if (secondif.getFirst().getExprents().isEmpty()) { + + firstif.getFirst().removeSuccessor(firstif.getIfEdge()); + + // remove first if + firstif.removeAllSuccessors(secondif); + + for (StatEdge edge : firstif.getAllPredecessorEdges()) { + if (!firstif.containsStatementStrict(edge.getSource())) { + firstif.removePredecessor(edge); + edge.getSource().changeEdgeNode(Statement.DIRECTION_FORWARD, edge, secondif); + secondif.addPredecessor(edge); + } + } + + parent.getStats().removeWithKey(firstif.id); + if (parent.getFirst() == firstif) { + parent.setFirst(secondif); + } + + // merge if conditions + IfExprent statexpr = secondif.getHeadexprent(); + + List<Exprent> lstOperands = new ArrayList<Exprent>(); + lstOperands.add(firstif.getHeadexprent().getCondition()); + + if (path == 2) { + lstOperands.set(0, new FunctionExprent(FunctionExprent.FUNCTION_BOOLNOT, + Arrays.asList(new Exprent[]{lstOperands.get(0)}))); + } + + lstOperands.add(statexpr.getCondition()); + + statexpr + .setCondition(new FunctionExprent(path == 1 ? FunctionExprent.FUNCTION_COR : FunctionExprent.FUNCTION_CADD, lstOperands)); + + if (secondif.getFirst().getExprents().isEmpty() && + !firstif.getFirst().getExprents().isEmpty()) { + + secondif.replaceStatement(secondif.getFirst(), firstif.getFirst()); + } + + return true; + } + } + } + else if (elsebranch.succs.size() == 1) { + + if (elsebranch.succs.get(0).value == rtnode.succs.get(0).value) { + + IfStatement firstif = (IfStatement)rtnode.value; + Statement second = elsebranch.value; + + firstif.removeAllSuccessors(second); + + for (StatEdge edge : second.getAllSuccessorEdges()) { + second.removeSuccessor(edge); + edge.setSource(firstif); + firstif.addSuccessor(edge); + } + + StatEdge ifedge = firstif.getIfEdge(); + firstif.getFirst().removeSuccessor(ifedge); + + second.addSuccessor(new StatEdge(ifedge.getType(), second, ifedge.getDestination(), ifedge.closure)); + + StatEdge newifedge = new StatEdge(StatEdge.TYPE_REGULAR, firstif.getFirst(), second); + firstif.getFirst().addSuccessor(newifedge); + firstif.setIfstat(second); + + firstif.getStats().addWithKey(second, second.id); + second.setParent(firstif); + + firstif.getParent().getStats().removeWithKey(second.id); + + // negate the if condition + IfExprent statexpr = firstif.getHeadexprent(); + statexpr + .setCondition(new FunctionExprent(FunctionExprent.FUNCTION_BOOLNOT, Arrays.asList(new Exprent[]{statexpr.getCondition()}))); + + return true; + } + } + } + + return false; + } + + + private static IfNode buildGraph(IfStatement stat, boolean stsingle) { + + if (stat.iftype == IfStatement.IFTYPE_IFELSE) { + return null; + } + + IfNode res = new IfNode(stat); + + // if branch + Statement ifchild = stat.getIfstat(); + if (ifchild == null) { + StatEdge edge = stat.getIfEdge(); + res.addChild(new IfNode(edge.getDestination()), 1); + } + else { + IfNode ifnode = new IfNode(ifchild); + res.addChild(ifnode, 0); + if (ifchild.type == Statement.TYPE_IF && ((IfStatement)ifchild).iftype == IfStatement.IFTYPE_IF) { + IfStatement stat2 = (IfStatement)ifchild; + Statement ifchild2 = stat2.getIfstat(); + if (ifchild2 == null) { + StatEdge edge = stat2.getIfEdge(); + ifnode.addChild(new IfNode(edge.getDestination()), 1); + } + else { + ifnode.addChild(new IfNode(ifchild2), 0); + } + } + + if (!ifchild.getAllSuccessorEdges().isEmpty()) { + ifnode.addChild(new IfNode(ifchild.getAllSuccessorEdges().get(0).getDestination()), 1); + } + } + + // else branch + StatEdge edge = stat.getAllSuccessorEdges().get(0); + Statement elsechild = edge.getDestination(); + IfNode elsenode = new IfNode(elsechild); + + if (stsingle || edge.getType() != StatEdge.TYPE_REGULAR) { + res.addChild(elsenode, 1); + } + else { + res.addChild(elsenode, 0); + if (elsechild.type == Statement.TYPE_IF && ((IfStatement)elsechild).iftype == IfStatement.IFTYPE_IF) { + IfStatement stat2 = (IfStatement)elsechild; + Statement ifchild2 = stat2.getIfstat(); + if (ifchild2 == null) { + elsenode.addChild(new IfNode(stat2.getIfEdge().getDestination()), 1); + } + else { + elsenode.addChild(new IfNode(ifchild2), 0); + } + } + + if (!elsechild.getAllSuccessorEdges().isEmpty()) { + elsenode.addChild(new IfNode(elsechild.getAllSuccessorEdges().get(0).getDestination()), 1); + } + } + + return res; + } + + + // FIXME: rewrite the entire method!!! keep in mind finally exits!! + private static boolean reorderIf(IfStatement ifstat) { + + if (ifstat.iftype == IfStatement.IFTYPE_IFELSE) { + return false; + } + + boolean ifdirect = false, elsedirect = false; + boolean noifstat = false, noelsestat = false; + boolean ifdirectpath = false, elsedirectpath = false; + + Statement parent = ifstat.getParent(); + Statement from = parent.type == Statement.TYPE_SEQUENCE ? parent : ifstat; + + Statement next = getNextStatement(from); + + if (ifstat.getIfstat() == null) { + noifstat = true; + + if (ifstat.getIfEdge().getType() == StatEdge.TYPE_FINALLYEXIT) { + ifdirect = true; + } + else { + ifdirect = MergeHelper.isDirectPath(from, ifstat.getIfEdge().getDestination()); + } + } + else { + List<StatEdge> lstSuccs = ifstat.getIfstat().getAllSuccessorEdges(); + if (!lstSuccs.isEmpty() && lstSuccs.get(0).getType() == StatEdge.TYPE_FINALLYEXIT) { + ifdirect = true; + } + else { + ifdirect = hasDirectEndEdge(ifstat.getIfstat(), from); + } + } + + Statement last = parent.type == Statement.TYPE_SEQUENCE ? parent.getStats().getLast() : ifstat; + noelsestat = (last == ifstat); + + if (!last.getAllSuccessorEdges().isEmpty() && last.getAllSuccessorEdges().get(0).getType() == StatEdge.TYPE_FINALLYEXIT) { + elsedirect = true; + } + else { + elsedirect = hasDirectEndEdge(last, from); + } + + if (!noelsestat && existsPath(ifstat, ifstat.getAllSuccessorEdges().get(0).getDestination())) { + return false; + } + + if (!ifdirect && !noifstat) { + ifdirectpath = existsPath(ifstat, next); + } + + if (!elsedirect && !noelsestat) { + SequenceStatement sequence = (SequenceStatement)parent; + + for (int i = sequence.getStats().size() - 1; i >= 0; i--) { + Statement sttemp = sequence.getStats().get(i); + if (sttemp == ifstat) { + break; + } + else { + if (elsedirectpath = existsPath(sttemp, next)) { + break; + } + } + } + } + + if ((ifdirect || ifdirectpath) && (elsedirect || elsedirectpath) && !noifstat && !noelsestat) { // if - then - else + + SequenceStatement sequence = (SequenceStatement)parent; + + // build and cut the new else statement + List<Statement> lst = new ArrayList<Statement>(); + for (int i = sequence.getStats().size() - 1; i >= 0; i--) { + Statement sttemp = sequence.getStats().get(i); + if (sttemp == ifstat) { + break; + } + else { + lst.add(0, sttemp); + } + } + + Statement stelse; + if (lst.size() == 1) { + stelse = lst.get(0); + } + else { + stelse = new SequenceStatement(lst); + stelse.setAllParent(); + } + + ifstat.removeSuccessor(ifstat.getAllSuccessorEdges().get(0)); + for (Statement st : lst) { + sequence.getStats().removeWithKey(st.id); + } + + StatEdge elseedge = new StatEdge(StatEdge.TYPE_REGULAR, ifstat.getFirst(), stelse); + ifstat.getFirst().addSuccessor(elseedge); + ifstat.setElsestat(stelse); + ifstat.setElseEdge(elseedge); + + ifstat.getStats().addWithKey(stelse, stelse.id); + stelse.setParent(ifstat); + + // if(next.type != Statement.TYPE_DUMMYEXIT && (ifdirect || elsedirect)) { + // StatEdge breakedge = new StatEdge(StatEdge.TYPE_BREAK, ifstat, next); + // sequence.addLabeledEdge(breakedge); + // ifstat.addSuccessor(breakedge); + // } + + ifstat.iftype = IfStatement.IFTYPE_IFELSE; + } + else if (ifdirect && (!elsedirect || (noifstat && !noelsestat))) { // if - then + + // negate the if condition + IfExprent statexpr = ifstat.getHeadexprent(); + statexpr.setCondition(new FunctionExprent(FunctionExprent.FUNCTION_BOOLNOT, Arrays.asList(new Exprent[]{statexpr.getCondition()}))); + + if (noelsestat) { + StatEdge ifedge = ifstat.getIfEdge(); + StatEdge elseedge = ifstat.getAllSuccessorEdges().get(0); + + if (noifstat) { + ifstat.getFirst().removeSuccessor(ifedge); + ifstat.removeSuccessor(elseedge); + + ifedge.setSource(ifstat); + elseedge.setSource(ifstat.getFirst()); + + ifstat.addSuccessor(ifedge); + ifstat.getFirst().addSuccessor(elseedge); + + ifstat.setIfEdge(elseedge); + } + else { + Statement ifbranch = ifstat.getIfstat(); + SequenceStatement newseq = new SequenceStatement(Arrays.asList(ifstat, ifbranch)); + + ifstat.getFirst().removeSuccessor(ifedge); + ifstat.getStats().removeWithKey(ifbranch.id); + ifstat.setIfstat(null); + + ifstat.removeSuccessor(elseedge); + elseedge.setSource(ifstat.getFirst()); + ifstat.getFirst().addSuccessor(elseedge); + + ifstat.setIfEdge(elseedge); + + ifstat.getParent().replaceStatement(ifstat, newseq); + newseq.setAllParent(); + + ifstat.addSuccessor(new StatEdge(StatEdge.TYPE_REGULAR, ifstat, ifbranch)); + } + } + else { + + SequenceStatement sequence = (SequenceStatement)parent; + + // build and cut the new else statement + List<Statement> lst = new ArrayList<Statement>(); + for (int i = sequence.getStats().size() - 1; i >= 0; i--) { + Statement sttemp = sequence.getStats().get(i); + if (sttemp == ifstat) { + break; + } + else { + lst.add(0, sttemp); + } + } + + Statement stelse; + if (lst.size() == 1) { + stelse = lst.get(0); + } + else { + stelse = new SequenceStatement(lst); + stelse.setAllParent(); + } + + ifstat.removeSuccessor(ifstat.getAllSuccessorEdges().get(0)); + for (Statement st : lst) { + sequence.getStats().removeWithKey(st.id); + } + + if (noifstat) { + StatEdge ifedge = ifstat.getIfEdge(); + + ifstat.getFirst().removeSuccessor(ifedge); + ifedge.setSource(ifstat); + ifstat.addSuccessor(ifedge); + } + else { + Statement ifbranch = ifstat.getIfstat(); + + ifstat.getFirst().removeSuccessor(ifstat.getIfEdge()); + ifstat.getStats().removeWithKey(ifbranch.id); + + ifstat.addSuccessor(new StatEdge(StatEdge.TYPE_REGULAR, ifstat, ifbranch)); + + sequence.getStats().addWithKey(ifbranch, ifbranch.id); + ifbranch.setParent(sequence); + } + + StatEdge newifedge = new StatEdge(StatEdge.TYPE_REGULAR, ifstat.getFirst(), stelse); + ifstat.getFirst().addSuccessor(newifedge); + ifstat.setIfstat(stelse); + ifstat.setIfEdge(newifedge); + + ifstat.getStats().addWithKey(stelse, stelse.id); + stelse.setParent(ifstat); + } + } + else { + return false; + } + + return true; + } + + private static boolean hasDirectEndEdge(Statement stat, Statement from) { + + for (StatEdge edge : stat.getAllSuccessorEdges()) { + if (MergeHelper.isDirectPath(from, edge.getDestination())) { + return true; + } + } + + if (stat.getExprents() == null) { + switch (stat.type) { + case Statement.TYPE_SEQUENCE: + return hasDirectEndEdge(stat.getStats().getLast(), from); + case Statement.TYPE_CATCHALL: + case Statement.TYPE_TRYCATCH: + for (Statement st : stat.getStats()) { + if (hasDirectEndEdge(st, from)) { + return true; + } + } + break; + case Statement.TYPE_IF: + IfStatement ifstat = (IfStatement)stat; + if (ifstat.iftype == IfStatement.IFTYPE_IFELSE) { + return hasDirectEndEdge(ifstat.getIfstat(), from) || + hasDirectEndEdge(ifstat.getElsestat(), from); + } + break; + case Statement.TYPE_SYNCRONIZED: + return hasDirectEndEdge(stat.getStats().get(1), from); + case Statement.TYPE_SWITCH: + for (Statement st : stat.getStats()) { + if (hasDirectEndEdge(st, from)) { + return true; + } + } + } + } + + return false; + } + + + private static Statement getNextStatement(Statement stat) { + + Statement parent = stat.getParent(); + switch (parent.type) { + case Statement.TYPE_ROOT: + return ((RootStatement)parent).getDummyExit(); + case Statement.TYPE_DO: + return parent; + case Statement.TYPE_SEQUENCE: + SequenceStatement sequence = (SequenceStatement)parent; + if (sequence.getStats().getLast() != stat) { + for (int i = sequence.getStats().size() - 1; i >= 0; i--) { + if (sequence.getStats().get(i) == stat) { + return sequence.getStats().get(i + 1); + } + } + } + } + + return getNextStatement(parent); + } + + private static boolean existsPath(Statement from, Statement to) { + + for (StatEdge edge : to.getAllPredecessorEdges()) { + if (from.containsStatementStrict(edge.getSource())) { + return true; + } + } + + return false; + } + + private static class IfNode { + public Statement value; + + public List<IfNode> succs = new ArrayList<IfNode>(); + public List<Integer> edgetypes = new ArrayList<Integer>(); + + public IfNode(Statement value) { + this.value = value; + } + + public void addChild(IfNode child, int type) { + succs.add(child); + edgetypes.add(new Integer(type)); + } + } +} |