--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graal/com.oracle.truffle.dsl.processor/src/com/oracle/truffle/dsl/processor/expression/DSLExpressionResolver.java	Fri Jan 23 02:55:23 2015 +0100
@@ -0,0 +1,220 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code 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 General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.oracle.truffle.dsl.processor.expression;
+
+import java.util.*;
+
+import javax.lang.model.element.*;
+import javax.lang.model.type.*;
+import javax.lang.model.util.*;
+
+import com.oracle.truffle.dsl.processor.*;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.Binary;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.Call;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.DSLExpressionVisitor;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.IntLiteral;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.Negate;
+import com.oracle.truffle.dsl.processor.expression.DSLExpression.Variable;
+import com.oracle.truffle.dsl.processor.java.*;
+import com.oracle.truffle.dsl.processor.java.model.*;
+
+public class DSLExpressionResolver implements DSLExpressionVisitor {
+
+    private static final List<String> LOGIC_OPERATORS = Arrays.asList("||");
+    private static final List<String> COMPARABLE_OPERATORS = Arrays.asList("<", "<=", ">", ">=");
+    private static final List<String> IDENTITY_OPERATORS = Arrays.asList("==", "!=");
+    private static final String CONSTRUCTOR_KEYWORD = "new";
+
+    private List<VariableElement> variables;
+    private List<ExecutableElement> methods;
+    private final ProcessorContext context;
+
+    public DSLExpressionResolver(ProcessorContext context, List<? extends Element> lookupElements) {
+        this.context = context;
+        this.variables = variablesIn(lookupElements, false);
+        this.methods = methodsIn(lookupElements);
+    }
+
+    private static List<ExecutableElement> methodsIn(List<? extends Element> lookupElements) {
+        List<ExecutableElement> methods = new ArrayList<>();
+        for (Element variable : lookupElements) {
+            ElementKind kind = variable.getKind();
+            if (kind == ElementKind.METHOD || kind == ElementKind.CONSTRUCTOR) {
+                methods.add((ExecutableElement) variable);
+            }
+        }
+        return methods;
+    }
+
+    private static List<VariableElement> variablesIn(List<? extends Element> lookupElements, boolean publicOnly) {
+        List<VariableElement> variables = new ArrayList<>();
+        for (Element variable : lookupElements) {
+            ElementKind kind = variable.getKind();
+            if (kind == ElementKind.LOCAL_VARIABLE || kind == ElementKind.PARAMETER || kind == ElementKind.FIELD || kind == ElementKind.ENUM_CONSTANT) {
+                VariableElement variableElement = (VariableElement) variable;
+                if (!publicOnly || variableElement.getModifiers().contains(Modifier.PUBLIC)) {
+                    variables.add(variableElement);
+                }
+            }
+        }
+        return variables;
+    }
+
+    private static String getMethodName(ExecutableElement method) {
+        if (method.getKind() == ElementKind.CONSTRUCTOR) {
+            return CONSTRUCTOR_KEYWORD;
+        } else {
+            return method.getSimpleName().toString();
+        }
+    }
+
+    public void visitBinary(Binary binary) {
+        String operator = binary.getOperator();
+        TypeMirror leftType = binary.getLeft().getResolvedType();
+        TypeMirror rightType = binary.getRight().getResolvedType();
+        if (!ElementUtils.typeEquals(leftType, rightType)) {
+            throw new InvalidExpressionException(String.format("Incompatible operand types %s and %s.", ElementUtils.getSimpleName(leftType), ElementUtils.getSimpleName(rightType)));
+        }
+
+        TypeMirror booleanType = context.getType(boolean.class);
+        boolean valid;
+        if (LOGIC_OPERATORS.contains(operator)) {
+            valid = ElementUtils.typeEquals(leftType, booleanType);
+        } else if (COMPARABLE_OPERATORS.contains(operator)) {
+            valid = ElementUtils.isPrimitive(leftType);
+        } else if (IDENTITY_OPERATORS.contains(operator)) {
+            valid = leftType.getKind().isPrimitive() || leftType.getKind() == TypeKind.DECLARED || leftType.getKind() == TypeKind.ARRAY;
+        } else {
+            throw new InvalidExpressionException(String.format("The operator %s is undefined.", operator));
+        }
+        binary.setResolvedType(booleanType);
+
+        if (!valid) {
+            throw new InvalidExpressionException(String.format("The operator %s is undefined for the argument type(s) %s %s.", operator, ElementUtils.getSimpleName(leftType),
+                            ElementUtils.getSimpleName(rightType)));
+        }
+    }
+
+    public void visitNegate(Negate negate) {
+        TypeMirror booleanType = context.getType(boolean.class);
+        TypeMirror resolvedType = negate.getResolvedType();
+        if (!ElementUtils.typeEquals(resolvedType, booleanType)) {
+            throw new InvalidExpressionException(String.format("The operator %s is undefined for the argument type %s.", "!", ElementUtils.getSimpleName(resolvedType)));
+        }
+    }
+
+    public void visitCall(Call call) {
+        List<ExecutableElement> lookupMethods;
+        DSLExpression receiver = call.getReceiver();
+        if (receiver == null) {
+            lookupMethods = this.methods;
+        } else {
+            TypeMirror type = receiver.getResolvedType();
+            if (type.getKind() == TypeKind.DECLARED) {
+                type = context.reloadType(type); // ensure ECJ has the type loaded
+                lookupMethods = ElementFilter.methodsIn(context.getEnvironment().getElementUtils().getAllMembers((TypeElement) ((DeclaredType) type).asElement()));
+            } else {
+                lookupMethods = Collections.emptyList();
+            }
+        }
+
+        ExecutableElement foundWithName = null;
+        outer: for (ExecutableElement method : lookupMethods) {
+            if (getMethodName(method).equals(call.getName())) {
+                foundWithName = method;
+
+                List<? extends VariableElement> parameters = method.getParameters();
+                if (parameters.size() != call.getParameters().size()) {
+                    continue outer;
+                }
+
+                int parameterIndex = 0;
+                for (DSLExpression expression : call.getParameters()) {
+                    TypeMirror sourceType = expression.getResolvedType();
+                    TypeMirror targetType = parameters.get(parameterIndex).asType();
+                    if (!ElementUtils.isAssignable(sourceType, targetType)) {
+                        continue outer;
+                    }
+                    parameterIndex++;
+                }
+                call.setResolvedMethod(method);
+                break;
+            }
+        }
+        if (call.getResolvedMethod() == null) {
+            if (foundWithName == null) {
+                // parameter mismatch
+                throw new InvalidExpressionException(String.format("The method %s is undefined for the enclosing scope.", call.getName()));
+            } else {
+                StringBuilder arguments = new StringBuilder();
+                String sep = "";
+                for (DSLExpression expression : call.getParameters()) {
+                    arguments.append(sep).append(ElementUtils.getSimpleName(expression.getResolvedType()));
+                    sep = ", ";
+                }
+                // name mismatch
+                throw new InvalidExpressionException(String.format("The method %s in the type %s is not applicable for the arguments %s.", //
+                                ElementUtils.getReadableSignature(foundWithName), //
+                                ElementUtils.getSimpleName((TypeElement) foundWithName.getEnclosingElement()), arguments.toString()));
+            }
+        }
+    }
+
+    public void visitVariable(Variable variable) {
+        List<VariableElement> lookupVariables;
+        DSLExpression receiver = variable.getReceiver();
+        if (receiver == null) {
+            lookupVariables = this.variables;
+        } else {
+            TypeMirror type = receiver.getResolvedType();
+            if (type.getKind() == TypeKind.DECLARED) {
+                type = context.reloadType(type); // ensure ECJ has the type loaded
+                lookupVariables = variablesIn(context.getEnvironment().getElementUtils().getAllMembers((TypeElement) ((DeclaredType) type).asElement()), true);
+            } else if (type.getKind() == TypeKind.ARRAY) {
+                lookupVariables = Arrays.<VariableElement> asList(new CodeVariableElement(context.getType(int.class), "length"));
+            } else {
+                lookupVariables = Collections.emptyList();
+            }
+        }
+
+        for (VariableElement variableElement : lookupVariables) {
+            if (variableElement.getSimpleName().toString().equals(variable.getName())) {
+                variable.setResolvedVariable(variableElement);
+                break;
+            }
+        }
+        if (variable.getResolvedVariable() == null) {
+            throw new InvalidExpressionException(String.format("%s cannot be resolved.", variable.getName()));
+        }
+    }
+
+    public void visitIntLiteral(IntLiteral binary) {
+        try {
+            binary.setResolvedType(context.getType(int.class));
+            binary.setResolvedValueInt(Integer.parseInt(binary.getLiteral()));
+        } catch (NumberFormatException e) {
+            throw new InvalidExpressionException(String.format("Type mismatch: cannot convert from String '%s' to int", binary.getLiteral()));
+        }
+    }
+
+}