/******************************************************************************
* Copyright (c) 2002 - 2006 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*****************************************************************************/
package com.ibm.wala.cast.js.translator;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import com.ibm.wala.cast.ir.translator.AstTranslator;
import com.ibm.wala.cast.js.loader.JSCallSiteReference;
import com.ibm.wala.cast.js.loader.JavaScriptLoader;
import com.ibm.wala.cast.js.ssa.JSInstructionFactory;
import com.ibm.wala.cast.js.ssa.JavaScriptInstanceOf;
import com.ibm.wala.cast.js.ssa.PrototypeLookup;
import com.ibm.wala.cast.js.types.JavaScriptMethods;
import com.ibm.wala.cast.js.types.JavaScriptTypes;
import com.ibm.wala.cast.loader.AstMethod.DebuggingInformation;
import com.ibm.wala.cast.tree.CAstEntity;
import com.ibm.wala.cast.tree.CAstNode;
import com.ibm.wala.cast.tree.CAstSymbol;
import com.ibm.wala.cast.tree.CAstType;
import com.ibm.wala.cast.tree.impl.CAstSymbolImpl;
import com.ibm.wala.cast.tree.visit.CAstVisitor;
import com.ibm.wala.cast.types.AstMethodReference;
import com.ibm.wala.cfg.AbstractCFG;
import com.ibm.wala.cfg.IBasicBlock;
import com.ibm.wala.classLoader.NewSiteReference;
import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SymbolTable;
import com.ibm.wala.types.FieldReference;
import com.ibm.wala.types.MethodReference;
import com.ibm.wala.types.TypeName;
import com.ibm.wala.types.TypeReference;
import com.ibm.wala.util.debug.Assertions;
import com.ibm.wala.util.strings.Atom;
/**
* Specialization of {@link AstTranslator} for JavaScript.
*
*/
public class JSAstTranslator extends AstTranslator {
private final static boolean DEBUG = false;
public JSAstTranslator(JavaScriptLoader loader) {
super(loader);
}
private boolean isPrologueScript(WalkContext context) {
return JavaScriptLoader.bootstrapFileNames.contains( context.getModule().getName() );
}
@Override
protected boolean useDefaultInitValues() {
return false;
}
@Override
protected boolean hasImplicitGlobals() {
return true;
}
@Override
protected boolean treatGlobalsAsLexicallyScoped() {
return false;
}
@Override
protected TypeReference defaultCatchType() {
return JavaScriptTypes.Root;
}
@Override
protected TypeReference makeType(CAstType type) {
assert "Any".equals(type.getName());
return JavaScriptTypes.Root;
}
@Override
protected boolean ignoreName(String name) {
return super.ignoreName(name) || name.endsWith(" temp");
}
@Override
protected String[] makeNameMap(CAstEntity n, Set<Scope> scopes, SSAInstruction[] insts) {
String[] names = super.makeNameMap(n, scopes, insts);
for(SSAInstruction inst : insts) {
if (inst instanceof PrototypeLookup) {
if (names[ inst.getUse(0)] != null) {
names[ inst.getDef() ] = names[ inst.getUse(0) ];
}
}
}
return names;
}
/**
* generate an instruction that checks if readVn is undefined and throws an exception if it isn't
*/
private void addDefinedCheck(CAstNode n, WalkContext context, int readVn) {
context.cfg().addPreNode(n);
context.cfg().addInstruction(((JSInstructionFactory)insts).CheckReference(context.cfg().getCurrentInstruction(), readVn));
CAstNode target = context.getControlFlow().getTarget(n, JavaScriptTypes.ReferenceError);
if (target != null) {
context.cfg().addPreEdge(n, target, true);
} else {
context.cfg().addPreEdgeToExit(n, true);
}
context.cfg().newBlock(true);
}
@Override
protected int doLexicallyScopedRead(CAstNode n, WalkContext context, String name, TypeReference type) {
int readVn = super.doLexicallyScopedRead(n, context, name, type);
// should get an exception if name is undefined
addDefinedCheck(n, context, readVn);
return readVn;
}
@Override
protected int doGlobalRead(CAstNode n, WalkContext context, String name, TypeReference type) {
int readVn = super.doGlobalRead(n, context, name, type);
// add a check if name is undefined, unless we're reading the value 'undefined'
if (n != null && !("undefined".equals(name) || "$$undefined".equals(name))) {
addDefinedCheck(n, context, readVn);
}
return readVn;
}
@Override
protected boolean defineType(CAstEntity type, WalkContext wc) {
Assertions.UNREACHABLE("JavaScript doesn't have types. I suggest you look elsewhere for your amusement.");
return false;
}
@Override
protected void defineField(CAstEntity topEntity, WalkContext wc, CAstEntity n) {
Assertions.UNREACHABLE("JavaScript doesn't have fields");
}
@Override
protected String composeEntityName(WalkContext parent, CAstEntity f) {
if (f.getKind() == CAstEntity.SCRIPT_ENTITY)
return f.getName();
else
return parent.getName() + "/" + f.getName();
}
@Override
protected void declareFunction(CAstEntity N, WalkContext context) {
String fnName = composeEntityName(context, N);
if (N.getKind() == CAstEntity.SCRIPT_ENTITY) {
((JavaScriptLoader) loader).defineScriptType("L" + fnName, N.getPosition(), N, context);
} else if (N.getKind() == CAstEntity.FUNCTION_ENTITY) {
((JavaScriptLoader) loader).defineFunctionType("L" + fnName, N.getPosition(), N, context);
} else {
Assertions.UNREACHABLE();
}
}
@Override
protected void defineFunction(CAstEntity N, WalkContext definingContext, AbstractCFG cfg, SymbolTable symtab,
boolean hasCatchBlock, Map<IBasicBlock,TypeReference[]> caughtTypes, boolean hasMonitorOp, AstLexicalInformation LI,
DebuggingInformation debugInfo) {
if (DEBUG)
System.err.println(("\n\nAdding code for " + N));
String fnName = composeEntityName(definingContext, N);
if (DEBUG)
System.err.println(cfg);
((JavaScriptLoader) loader).defineCodeBodyCode("L" + fnName, cfg, symtab, hasCatchBlock, caughtTypes, hasMonitorOp, LI,
debugInfo);
}
@Override
protected void doThrow(WalkContext context, int exception) {
context.cfg().addInstruction(insts.ThrowInstruction(context.cfg().getCurrentInstruction(), exception));
}
@Override
protected void doCall(WalkContext context, CAstNode call, int result, int exception, CAstNode name, int receiver, int[] arguments) {
MethodReference ref =
name.getValue().equals("ctor") ? JavaScriptMethods.ctorReference
: name.getValue().equals("dispatch") ? JavaScriptMethods.dispatchReference
: AstMethodReference.fnReference(JavaScriptTypes.CodeBody);
context.cfg().addInstruction(
((JSInstructionFactory) insts).Invoke(context.cfg().getCurrentInstruction(), receiver, result, arguments, exception,
new JSCallSiteReference(ref, context.cfg().getCurrentInstruction())));
context.cfg().addPreNode(call, context.getUnwindState());
// this new block is for the normal termination case
context.cfg().newBlock(true);
// exceptional case: flow to target given in CAst, or if null, the exit node
if (context.getControlFlow().getTarget(call, null) != null)
context.cfg().addPreEdge(call, context.getControlFlow().getTarget(call, null), true);
else
context.cfg().addPreEdgeToExit(call, true);
}
@Override
protected void doNewObject(WalkContext context, CAstNode newNode, int result, Object type, int[] arguments) {
assert arguments == null;
TypeReference typeRef = TypeReference.findOrCreate(JavaScriptTypes.jsLoader, TypeName.string2TypeName("L" + type));
context.cfg().addInstruction(insts.NewInstruction(context.cfg().getCurrentInstruction(), result,
NewSiteReference.make(context.cfg().getCurrentInstruction(), typeRef)));
}
@Override
protected void doMaterializeFunction(CAstNode n, WalkContext context, int result, int exception, CAstEntity fn) {
int nm = context.currentScope().getConstantValue("L" + composeEntityName(context, fn));
// "Function" is the name we use to model the constructor of function values
int tmp = super.doGlobalRead(n, context, "Function", JavaScriptTypes.Function);
context.cfg().addInstruction(
((JSInstructionFactory)insts).Invoke(context.cfg().getCurrentInstruction(), tmp, result, new int[]{ nm }, exception,
new JSCallSiteReference(JavaScriptMethods.ctorReference, context.cfg().getCurrentInstruction())));
}
@Override
public void doArrayRead(WalkContext context, int result, int arrayValue, CAstNode arrayRef, int[] dimValues) {
Assertions.UNREACHABLE("JSAstTranslator.doArrayRead() called!");
}
@Override
public void doArrayWrite(WalkContext context, int arrayValue, CAstNode arrayRef, int[] dimValues, int rval) {
Assertions.UNREACHABLE("JSAstTranslator.doArrayWrite() called!");
}
@Override
protected void doFieldRead(WalkContext context, int result, int receiver, CAstNode elt, CAstNode readNode) {
this.visit(elt, context, this);
int x = context.currentScope().allocateTempValue();
context.cfg().addInstruction(((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(), x, receiver));
context.cfg().addInstruction(((JSInstructionFactory) insts).PrototypeLookup(context.cfg().getCurrentInstruction(), x, x));
if (elt.getKind() == CAstNode.CONSTANT && elt.getValue() instanceof String) {
String field = (String) elt.getValue();
// symtab needs to have this value
context.currentScope().getConstantValue(field);
context.cfg().addInstruction(
((JSInstructionFactory)insts).GetInstruction(context.cfg().getCurrentInstruction(), result, x, field));
} else {
context.cfg().addInstruction(((JSInstructionFactory) insts).PropertyRead(context.cfg().getCurrentInstruction(), result, x, context.getValue(elt)));
}
// generate code to handle read of property from null or undefined
context.cfg().addPreNode(readNode, context.getUnwindState());
context.cfg().newBlock(true);
if (context.getControlFlow().getTarget(readNode, JavaScriptTypes.TypeError) != null)
context.cfg().addPreEdge(readNode, context.getControlFlow().getTarget(readNode, JavaScriptTypes.TypeError), true);
else
context.cfg().addPreEdgeToExit(readNode, true);
}
@Override
protected void doFieldWrite(WalkContext context, int receiver, CAstNode elt, CAstNode parent, int rval) {
this.visit(elt, context, this);
if (elt.getKind() == CAstNode.CONSTANT && elt.getValue() instanceof String) {
String field = (String) elt.getValue();
if (isPrologueScript(context) && "__proto__".equals(field)) {
context.cfg().addInstruction(((JSInstructionFactory) insts).SetPrototype(context.cfg().getCurrentInstruction(), receiver, rval));
return;
}
}
/*
} else {
context.currentScope().getConstantValue(field);
SSAPutInstruction put = ((JSInstructionFactory) insts).PutInstruction(context.cfg().getCurrentInstruction(), receiver, rval, field);
try {
assert field.equals(put.getDeclaredField().getName().toUnicodeString());
} catch (UTFDataFormatException e) {
Assertions.UNREACHABLE();
}
context.cfg().addInstruction(put);
}
} else {
*/
context.cfg().addInstruction(((JSInstructionFactory) insts).PropertyWrite(context.cfg().getCurrentInstruction(), receiver, context.getValue(elt), rval));
context.cfg().addPreNode(parent, context.getUnwindState());
// generate code to handle read of property from null or undefined
context.cfg().newBlock(true);
if (context.getControlFlow().getTarget(parent, JavaScriptTypes.TypeError) != null)
context.cfg().addPreEdge(parent, context.getControlFlow().getTarget(parent, JavaScriptTypes.TypeError), true);
else
context.cfg().addPreEdgeToExit(parent, true);
// }
}
private void doPrimitiveNew(WalkContext context, int resultVal, String typeName) {
doNewObject(context, null, resultVal, typeName + "Object", null);
// set the class property of the new object
int rval = context.currentScope().getConstantValue(typeName);
context.currentScope().getConstantValue("class");
context.cfg().addInstruction(
((JSInstructionFactory)insts).PutInstruction(context.cfg().getCurrentInstruction(), resultVal, rval, "class"));
}
@Override
protected void doPrimitive(int resultVal, WalkContext context, CAstNode primitiveCall) {
try {
String name = (String) primitiveCall.getChild(0).getValue();
if (name.equals("GlobalNaN")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Float(Float.NaN))));
} else if (name.equals("GlobalInfinity")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Float(Float.POSITIVE_INFINITY))));
} else if (name.equals("MathE")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.E))));
} else if (name.equals("MathPI")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.PI))));
} else if (name.equals("MathSQRT1_2")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.sqrt(.5)))));
} else if (name.equals("MathSQRT2")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.sqrt(2)))));
} else if (name.equals("MathLN2")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.log(2)))));
} else if (name.equals("MathLN10")) {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue(new Double(Math.log(10)))));
} else if (name.equals("NewObject")) {
doNewObject(context, null, resultVal, "Object", null);
} else if (name.equals("NewArray")) {
doNewObject(context, null, resultVal, "Array", null);
} else if (name.equals("NewString")) {
doPrimitiveNew(context, resultVal, "String");
} else if (name.equals("NewNumber")) {
doPrimitiveNew(context, resultVal, "Number");
} else if (name.equals("NewRegExp")) {
doPrimitiveNew(context, resultVal, "RegExp");
} else if (name.equals("NewFunction")) {
doNewObject(context, null, resultVal, "Function", null);
} else if (name.equals("NewUndefined")) {
doNewObject(context, null, resultVal, "Undefined", null);
} else {
context.cfg().addInstruction(
((JSInstructionFactory)insts).AssignInstruction(context.cfg().getCurrentInstruction(),
resultVal, context.currentScope().getConstantValue( null )));
}
} catch (ClassCastException e) {
throw new RuntimeException("Cannot translate primitive " + primitiveCall.getChild(0).getValue());
}
}
@Override
protected void doIsFieldDefined(WalkContext context, int result, int ref, CAstNode f) {
if (f.getKind() == CAstNode.CONSTANT && f.getValue() instanceof String) {
String field = (String) f.getValue();
FieldReference fieldRef = FieldReference.findOrCreate(JavaScriptTypes.Root, Atom.findOrCreateUnicodeAtom(field),
JavaScriptTypes.Root);
context.cfg().addInstruction(((JSInstructionFactory) insts).IsDefinedInstruction(context.cfg().getCurrentInstruction(), result, ref, fieldRef));
} else {
context.cfg().addInstruction(((JSInstructionFactory) insts).IsDefinedInstruction(context.cfg().getCurrentInstruction(), result, ref, context.getValue(f)));
}
}
@Override
protected boolean visitInstanceOf(CAstNode n, WalkContext c, CAstVisitor<WalkContext> visitor) {
WalkContext context = c;
int result = context.currentScope().allocateTempValue();
context.setValue(n, result);
return false;
}
@Override
protected void leaveInstanceOf(CAstNode n, WalkContext c, CAstVisitor<WalkContext> visitor) {
WalkContext context = c;
int result = context.getValue(n);
visit(n.getChild(0), context, visitor);
int value = context.getValue(n.getChild(0));
visit(n.getChild(1), context, visitor);
int type = context.getValue(n.getChild(1));
context.cfg().addInstruction(new JavaScriptInstanceOf(context.cfg().getCurrentInstruction(), result, value, type));
}
@Override
protected void doPrologue(WalkContext context) {
super.doPrologue(context);
int tempVal = context.currentScope().allocateTempValue();
doNewObject(context, null, tempVal, "Array", null);
CAstSymbol args = new CAstSymbolImpl("arguments", Any);
context.currentScope().declare(args, tempVal);
//context.cfg().addInstruction(((JSInstructionFactory)insts).PutInstruction(context.cfg().getCurrentInstruction(), 1, tempVal, "arguments"));
}
@Override
protected boolean doVisit(CAstNode n, WalkContext context, CAstVisitor<WalkContext> visitor) {
switch (n.getKind()) {
case CAstNode.TYPE_OF: {
int result = context.currentScope().allocateTempValue();
this.visit(n.getChild(0), context, this);
int ref = context.getValue(n.getChild(0));
context.cfg().addInstruction(((JSInstructionFactory)insts).TypeOfInstruction(context.cfg().getCurrentInstruction(), result, ref));
context.setValue(n, result);
return true;
}
case JavaScriptCAstNode.ENTER_WITH:
case JavaScriptCAstNode.EXIT_WITH: {
this.visit(n.getChild(0), context, this);
int ref = context.getValue(n.getChild(0));
context.cfg().addInstruction(((JSInstructionFactory)insts).WithRegion(context.cfg().getCurrentInstruction(), ref,
n.getKind() == JavaScriptCAstNode.ENTER_WITH));
return true;
}
default: {
return false;
}
}
}
public static final CAstType Any = new CAstType() {
@Override
public String getName() {
return "Any";
}
@Override
public Collection getSupertypes() {
return Collections.EMPTY_SET;
}
};
@Override
protected CAstType topType() {
return Any;
}
@Override
protected CAstType exceptionType() {
return Any;
}
}