86 lines
2.9 KiB
Java
86 lines
2.9 KiB
Java
package com.ibm.wala.cast.tree.rewrite;
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import java.util.Collection;
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import java.util.Iterator;
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import java.util.Map;
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import java.util.Set;
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import com.ibm.wala.cast.tree.CAstControlFlowMap;
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import com.ibm.wala.cast.tree.CAstEntity;
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import com.ibm.wala.cast.tree.CAstNode;
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import com.ibm.wala.cast.tree.CAstNodeTypeMap;
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import com.ibm.wala.cast.tree.CAstSourcePositionMap;
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import com.ibm.wala.cast.tree.impl.CAstImpl;
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import com.ibm.wala.cast.tree.impl.DelegatingEntity;
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import com.ibm.wala.cast.tree.rewrite.CAstBasicRewriter.NonCopyingContext;
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import com.ibm.wala.cast.tree.rewrite.CAstRewriter.Rewrite;
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import com.ibm.wala.cast.util.AstConstantCollector;
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import com.ibm.wala.util.collections.EmptyIterator;
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import com.ibm.wala.util.collections.HashSetFactory;
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import com.ibm.wala.util.collections.Pair;
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public class AstConstantFolder {
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static class AssignSkipContext extends NonCopyingContext {
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private Set<CAstNode> skip = HashSetFactory.make();
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}
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public static CAstEntity fold(CAstEntity ce) {
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Map<String,Object> constants = AstConstantCollector.collectConstants(ce);
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if (constants.isEmpty()) {
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return ce;
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} else {
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Rewrite nce = new CAstCloner(new CAstImpl(), new AssignSkipContext(), true) {
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@Override
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protected CAstNode copyNodes(CAstNode root, CAstControlFlowMap cfg, NonCopyingContext c,
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Map<Pair<CAstNode, NoKey>, CAstNode> nodeMap) {
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if (root.getKind() == CAstNode.ASSIGN) {
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((AssignSkipContext)c).skip.add(root.getChild(0));
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}
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if (root.getKind() == CAstNode.VAR && constants.containsKey(root.getChild(0).getValue()) && ! ((AssignSkipContext)c).skip.contains(root)) {
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return Ast.makeConstant(constants.get(root.getChild(0).getValue()));
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} else {
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return super.copyNodes(root, cfg, c, nodeMap);
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}
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}
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}.rewrite(ce.getAST(), ce.getControlFlow(), ce.getSourceMap(), ce.getNodeTypeMap(), ce.getAllScopedEntities(), ce.getArgumentDefaults());
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return new DelegatingEntity(ce) {
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@Override
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public CAstNode getAST() {
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return nce.newRoot();
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}
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@Override
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public CAstControlFlowMap getControlFlow() {
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return nce.newCfg();
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}
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@Override
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public CAstSourcePositionMap getSourceMap() {
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return nce.newPos();
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}
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@Override
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public CAstNodeTypeMap getNodeTypeMap() {
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return nce.newTypes();
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}
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@Override
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public Map<CAstNode, Collection<CAstEntity>> getAllScopedEntities() {
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return nce.newChildren();
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}
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@Override
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public Iterator<CAstEntity> getScopedEntities(CAstNode construct) {
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Collection<CAstEntity> children = nce.newChildren().get(construct);
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return children==null? EmptyIterator.instance(): children.iterator();
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}
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};
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}
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}
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}
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