org.walkmod.javalang.compiler.actions.RemoveUnusedSymbolsAction Maven / Gradle / Ivy
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Library of compiler components to processs Java code.
/*
* Copyright (C) 2015 Raquel Pau and Albert Coroleu.
*
* Walkmod is free software: you can redistribute it and/or modify it under the terms of the GNU
* Lesser General Public License as published by the Free Software Foundation, either version 3 of
* the License, or (at your option) any later version.
*
* Walkmod 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 Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License along with Walkmod. If
* not, see attrs = symbol.getAttributes();
Object reads = attrs.get(ReferencesCounterAction.READS);
Object writes = attrs.get(ReferencesCounterAction.WRITES);
if (reads == null && writes == null) {
if (n instanceof MethodDeclaration) {
removeMethod(symbol, table);
} else if (n instanceof VariableDeclarator) {
Node parentNode = n.getParentNode();
if (parentNode != null) {
if (parentNode instanceof FieldDeclaration) {
removeField(symbol, table, (FieldDeclaration) parentNode);
} else {
removeVariable(symbol, table, (VariableDeclarationExpr) parentNode);
}
}
} else if (n instanceof TypeDeclaration) {
Symbol thisSymbol = table.findSymbol("this", ReferenceType.VARIABLE);
if (symbol.getReferenceType().equals(ReferenceType.TYPE) && thisSymbol != null
&& !thisSymbol.getType().equals(symbol.getType())) {
removeType(symbol, table);
}
} else if (n instanceof ImportDeclaration) {
removeImport(symbol, table);
}
}
}
}
public List getSiblings() {
return siblings;
}
public void removeImport(Symbol symbol, SymbolTable table) {
ImportDeclaration id = (ImportDeclaration) symbol.getLocation();
if (id.isAsterisk() || id.isStatic()) {
String type = id.getName().toString();
if (!id.isAsterisk()) {
int pos = type.lastIndexOf('.');
type = type.substring(0, pos);
}
List> symbols = table.findSymbolsByType(type, ReferenceType.TYPE);
boolean used = false;
List> staticElems = null;
if (id.isStatic()) {
staticElems = table.findSymbolsByLocation(id);
}
Iterator> it = symbols.iterator();
while (it.hasNext() && !used) {
Symbol candidate = it.next();
if (id.isStatic()) {
Iterator> itStatic = staticElems.iterator();
while (itStatic.hasNext() && !used) {
Symbol staticElem = itStatic.next();
ReferenceType rt = staticElem.getReferenceType();
if (rt.equals(ReferenceType.METHOD) || rt.equals(ReferenceType.VARIABLE)) {
Map attrs = staticElem.getAttributes();
Object reads = attrs.get(ReferencesCounterAction.READS);
Object writes = attrs.get(ReferencesCounterAction.WRITES);
used = (reads != null || writes != null);
}
}
if (!used) {
Map attrs = candidate.getAttributes();
Object reads = attrs.get(ReferencesCounterAction.READS);
used = (reads != null);
}
}
}
if (!used) {
remove(id);
}
} else {
String type = id.getName().toString();
// internal classes
List> symbols = table.findSymbolsByType(type, ReferenceType.TYPE);
boolean used = false;
Iterator> it = symbols.iterator();
while (it.hasNext() && !used) {
Symbol next = it.next();
Map attrs = next.getAttributes();
Object reads = attrs.get(ReferencesCounterAction.READS);
Object writes = attrs.get(ReferencesCounterAction.WRITES);
used = (reads != null || writes != null);
}
if (!used) {
remove(id);
}
}
}
private void remove(Object o) {
Iterator it = siblings.iterator();
boolean removed = false;
while (it.hasNext() && !removed) {
Node aux = it.next();
if (aux == o) { // yes, by reference
it.remove();
removed = true;
}
}
}
public void removeMethod(Symbol symbol, SymbolTable table) {
MethodDeclaration md = (MethodDeclaration) symbol.getLocation();
int modifiers = md.getModifiers();
if (ModifierSet.isPrivate(modifiers)) {
remove(md);
}
}
public void removeType(Symbol symbol, SymbolTable table) {
TypeDeclaration td = (TypeDeclaration) symbol.getLocation();
int modifiers = td.getModifiers();
if (ModifierSet.isPrivate(modifiers)) {
remove(td);
}
}
public void removeVariable(Symbol symbol, SymbolTable table, VariableDeclarationExpr vd) {
List vds = vd.getVars();
if (vds.size() == 1) {
Expression init = vds.get(0).getInit();
if (isReadOnlyExpression(init)) {
remove(vd.getParentNode());
}
} else {
Iterator it = vds.iterator();
boolean finish = false;
while (it.hasNext() && !finish) {
VariableDeclarator current = it.next();
if (current.getId().getName().equals(symbol.getName())) {
if (isReadOnlyExpression(current.getInit())) {
finish = true;
it.remove();
}
}
}
}
}
private boolean isReadOnlyExpression(Expression init) {
return (init == null || init instanceof LiteralExpr || init instanceof NameExpr);
}
public void removeField(Symbol symbol, SymbolTable table, FieldDeclaration fd) {
int modifiers = fd.getModifiers();
if (ModifierSet.isPrivate(modifiers)) {
List vds = fd.getVariables();
if (vds != null) {
Iterator it = vds.iterator();
while (it.hasNext()) {
VariableDeclarator vd = it.next();
if (vd.getId().getName().equals(symbol.getName())) {
Expression init = vd.getInit();
if (isReadOnlyExpression(init)) {
if (vds.size() == 1) {
remove(fd);
} else {
it.remove();
}
}
}
}
}
}
}
}
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