--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/truffle/com.oracle.truffle.sl/src/com/oracle/truffle/sl/parser/SLNodeFactory.java	Wed Jun 17 10:58:08 2015 +0200
@@ -0,0 +1,382 @@
+/*
+ * Copyright (c) 2012, 2014, 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.sl.parser;
+
+import java.math.*;
+import java.util.*;
+
+import com.oracle.truffle.api.frame.*;
+import com.oracle.truffle.api.nodes.*;
+import com.oracle.truffle.api.source.*;
+import com.oracle.truffle.sl.nodes.*;
+import com.oracle.truffle.sl.nodes.access.*;
+import com.oracle.truffle.sl.nodes.call.*;
+import com.oracle.truffle.sl.nodes.controlflow.*;
+import com.oracle.truffle.sl.nodes.expression.*;
+import com.oracle.truffle.sl.nodes.local.*;
+import com.oracle.truffle.sl.runtime.*;
+
+/**
+ * Helper class used by the SL {@link Parser} to create nodes. The code is factored out of the
+ * automatically generated parser to keep the attributed grammar of SL small.
+ */
+public class SLNodeFactory {
+
+    /**
+     * Local variable names that are visible in the current block. Variables are not visible outside
+     * of their defining block, to prevent the usage of undefined variables. Because of that, we can
+     * decide during parsing if a name references a local variable or is a function name.
+     */
+    static class LexicalScope {
+        protected final LexicalScope outer;
+        protected final Map<String, FrameSlot> locals;
+
+        public LexicalScope(LexicalScope outer) {
+            this.outer = outer;
+            this.locals = new HashMap<>();
+            if (outer != null) {
+                locals.putAll(outer.locals);
+            }
+        }
+    }
+
+    /* State while parsing a source unit. */
+    private final SLContext context;
+    private final Source source;
+
+    /* State while parsing a function. */
+    private int functionStartPos;
+    private String functionName;
+    private int functionBodyStartPos; // includes parameter list
+    private int parameterCount;
+    private FrameDescriptor frameDescriptor;
+    private List<SLStatementNode> methodNodes;
+
+    /* State while parsing a block. */
+    private LexicalScope lexicalScope;
+
+    public SLNodeFactory(SLContext context, Source source) {
+        this.context = context;
+        this.source = source;
+    }
+
+    public void startFunction(Token nameToken, int bodyStartPos) {
+        assert functionStartPos == 0;
+        assert functionName == null;
+        assert functionBodyStartPos == 0;
+        assert parameterCount == 0;
+        assert frameDescriptor == null;
+        assert lexicalScope == null;
+
+        functionStartPos = nameToken.charPos;
+        functionName = nameToken.val;
+        functionBodyStartPos = bodyStartPos;
+        frameDescriptor = new FrameDescriptor();
+        methodNodes = new ArrayList<>();
+        startBlock();
+    }
+
+    public void addFormalParameter(Token nameToken) {
+        /*
+         * Method parameters are assigned to local variables at the beginning of the method. This
+         * ensures that accesses to parameters are specialized the same way as local variables are
+         * specialized.
+         */
+        final SourceSection src = srcFromToken(nameToken);
+        final SLReadArgumentNode readArg = new SLReadArgumentNode(src, parameterCount);
+        methodNodes.add(createAssignment(nameToken, readArg));
+        parameterCount++;
+    }
+
+    public void finishFunction(SLStatementNode bodyNode) {
+        methodNodes.add(bodyNode);
+        final int bodyEndPos = bodyNode.getSourceSection().getCharEndIndex();
+        final SourceSection functionSrc = source.createSection(functionName, functionStartPos, bodyEndPos - functionStartPos);
+        final SLStatementNode methodBlock = finishBlock(methodNodes, functionBodyStartPos, bodyEndPos - functionBodyStartPos);
+        assert lexicalScope == null : "Wrong scoping of blocks in parser";
+
+        final SLFunctionBodyNode functionBodyNode = new SLFunctionBodyNode(functionSrc, methodBlock);
+        final SLRootNode rootNode = new SLRootNode(this.context, frameDescriptor, functionBodyNode, functionName);
+        rootNode.assignSourceSection(functionSrc);
+
+        context.getFunctionRegistry().register(functionName, rootNode);
+
+        functionStartPos = 0;
+        functionName = null;
+        functionBodyStartPos = 0;
+        parameterCount = 0;
+        frameDescriptor = null;
+        lexicalScope = null;
+    }
+
+    public void startBlock() {
+        lexicalScope = new LexicalScope(lexicalScope);
+    }
+
+    public SLStatementNode finishBlock(List<SLStatementNode> bodyNodes, int startPos, int length) {
+        lexicalScope = lexicalScope.outer;
+
+        List<SLStatementNode> flattenedNodes = new ArrayList<>(bodyNodes.size());
+        flattenBlocks(bodyNodes, flattenedNodes);
+
+        final SourceSection src = source.createSection("block", startPos, length);
+        return new SLBlockNode(src, flattenedNodes.toArray(new SLStatementNode[flattenedNodes.size()]));
+    }
+
+    private void flattenBlocks(Iterable<? extends Node> bodyNodes, List<SLStatementNode> flattenedNodes) {
+        for (Node n : bodyNodes) {
+            if (n instanceof SLBlockNode) {
+                flattenBlocks(n.getChildren(), flattenedNodes);
+            } else {
+                flattenedNodes.add((SLStatementNode) n);
+            }
+        }
+    }
+
+    /**
+     * Returns an {@link SLBreakNode} for the given token.
+     *
+     * @param breakToken The token containing the break node's info.
+     * @return A SLBreakNode for the given token.
+     */
+    public SLStatementNode createBreak(Token breakToken) {
+        final SLBreakNode breakNode = new SLBreakNode(srcFromToken(breakToken));
+        return breakNode;
+    }
+
+    /**
+     * Returns an {@link SLContinueNode} for the given token.
+     *
+     * @param continueToken The token containing the continue node's info.
+     * @return A SLContinueNode built using the given token.
+     */
+    public SLStatementNode createContinue(Token continueToken) {
+        final SLContinueNode continueNode = new SLContinueNode(srcFromToken(continueToken));
+        return continueNode;
+    }
+
+    /**
+     * Returns an {@link SLWhileNode} for the given parameters.
+     *
+     * @param whileToken The token containing the while node's info
+     * @param conditionNode The conditional node for this while loop
+     * @param bodyNode The body of the while loop
+     * @return A SLWhileNode built using the given parameters.
+     */
+    public SLStatementNode createWhile(Token whileToken, SLExpressionNode conditionNode, SLStatementNode bodyNode) {
+        final int start = whileToken.charPos;
+        final int end = bodyNode.getSourceSection().getCharEndIndex();
+        final SLWhileNode whileNode = new SLWhileNode(source.createSection(whileToken.val, start, end - start), conditionNode, bodyNode);
+        return whileNode;
+    }
+
+    /**
+     * Returns an {@link SLIfNode} for the given parameters.
+     *
+     * @param ifToken The token containing the if node's info
+     * @param conditionNode The condition node of this if statement
+     * @param thenPartNode The then part of the if
+     * @param elsePartNode The else part of the if
+     * @return An SLIfNode for the given parameters.
+     */
+    public SLStatementNode createIf(Token ifToken, SLExpressionNode conditionNode, SLStatementNode thenPartNode, SLStatementNode elsePartNode) {
+        final int start = ifToken.charPos;
+        final int end = elsePartNode == null ? thenPartNode.getSourceSection().getCharEndIndex() : elsePartNode.getSourceSection().getCharEndIndex();
+        final SLIfNode ifNode = new SLIfNode(source.createSection(ifToken.val, start, end - start), conditionNode, thenPartNode, elsePartNode);
+        return ifNode;
+    }
+
+    /**
+     * Returns an {@link SLReturnNode} for the given parameters.
+     *
+     * @param t The token containing the return node's info
+     * @param valueNode The value of the return
+     * @return An SLReturnNode for the given parameters.
+     */
+    public SLStatementNode createReturn(Token t, SLExpressionNode valueNode) {
+        final int start = t.charPos;
+        final int length = valueNode == null ? t.val.length() : valueNode.getSourceSection().getCharEndIndex() - start;
+        final SLReturnNode returnNode = new SLReturnNode(source.createSection(t.val, start, length), valueNode);
+        return returnNode;
+    }
+
+    /**
+     * Returns the corresponding subclass of {@link SLExpressionNode} for binary expressions.
+     * </br>These nodes are currently not instrumented.
+     *
+     * @param opToken The operator of the binary expression
+     * @param leftNode The left node of the expression
+     * @param rightNode The right node of the expression
+     * @return A subclass of SLExpressionNode using the given parameters based on the given opToken.
+     */
+    public SLExpressionNode createBinary(Token opToken, SLExpressionNode leftNode, SLExpressionNode rightNode) {
+        int start = leftNode.getSourceSection().getCharIndex();
+        int length = rightNode.getSourceSection().getCharEndIndex() - start;
+        final SourceSection src = source.createSection(opToken.val, start, length);
+        switch (opToken.val) {
+            case "+":
+                return SLAddNodeGen.create(src, leftNode, rightNode);
+            case "*":
+                return SLMulNodeGen.create(src, leftNode, rightNode);
+            case "/":
+                return SLDivNodeGen.create(src, leftNode, rightNode);
+            case "-":
+                return SLSubNodeGen.create(src, leftNode, rightNode);
+            case "<":
+                return SLLessThanNodeGen.create(src, leftNode, rightNode);
+            case "<=":
+                return SLLessOrEqualNodeGen.create(src, leftNode, rightNode);
+            case ">":
+                return SLLogicalNotNodeGen.create(src, SLLessOrEqualNodeGen.create(null, leftNode, rightNode));
+            case ">=":
+                return SLLogicalNotNodeGen.create(src, SLLessThanNodeGen.create(null, leftNode, rightNode));
+            case "==":
+                return SLEqualNodeGen.create(src, leftNode, rightNode);
+            case "!=":
+                return SLLogicalNotNodeGen.create(src, SLEqualNodeGen.create(null, leftNode, rightNode));
+            case "&&":
+                return SLLogicalAndNodeGen.create(src, leftNode, rightNode);
+            case "||":
+                return SLLogicalOrNodeGen.create(src, leftNode, rightNode);
+            default:
+                throw new RuntimeException("unexpected operation: " + opToken.val);
+        }
+    }
+
+    /**
+     * Returns an {@link SLInvokeNode} for the given parameters.
+     *
+     * @param functionNode The function being called
+     * @param parameterNodes The parameters of the function call
+     * @param finalToken A token used to determine the end of the sourceSelection for this call
+     * @return An SLInvokeNode for the given parameters.
+     */
+    public SLExpressionNode createCall(SLExpressionNode functionNode, List<SLExpressionNode> parameterNodes, Token finalToken) {
+        final int startPos = functionNode.getSourceSection().getCharIndex();
+        final int endPos = finalToken.charPos + finalToken.val.length();
+        final SourceSection src = source.createSection(functionNode.getSourceSection().getIdentifier(), startPos, endPos - startPos);
+        return SLInvokeNode.create(src, functionNode, parameterNodes.toArray(new SLExpressionNode[parameterNodes.size()]));
+    }
+
+    /**
+     * Returns an {@link SLWriteLocalVariableNode} for the given parameters.
+     *
+     * @param nameToken The name of the variable being assigned
+     * @param valueNode The value to be assigned
+     * @return An SLExpressionNode for the given parameters.
+     */
+    public SLExpressionNode createAssignment(Token nameToken, SLExpressionNode valueNode) {
+        FrameSlot frameSlot = frameDescriptor.findOrAddFrameSlot(nameToken.val);
+        lexicalScope.locals.put(nameToken.val, frameSlot);
+        final int start = nameToken.charPos;
+        final int length = valueNode.getSourceSection().getCharEndIndex() - start;
+        return SLWriteLocalVariableNodeGen.create(source.createSection("=", start, length), valueNode, frameSlot);
+    }
+
+    /**
+     * Returns a {@link SLReadLocalVariableNode} if this read is a local variable or a
+     * {@link SLFunctionLiteralNode} if this read is global. In Simple, the only global names are
+     * functions. </br> There is currently no instrumentation for this node.
+     *
+     * @param nameToken The name of the variable/function being read
+     * @return either:
+     *         <ul>
+     *         <li>A SLReadLocalVariableNode representing the local variable being read.</li>
+     *         <li>A SLFunctionLiteralNode representing the function definition</li>
+     *         </ul>
+     */
+    public SLExpressionNode createRead(Token nameToken) {
+        final FrameSlot frameSlot = lexicalScope.locals.get(nameToken.val);
+        final SourceSection src = srcFromToken(nameToken);
+        if (frameSlot != null) {
+            /* Read of a local variable. */
+            return SLReadLocalVariableNodeGen.create(src, frameSlot);
+        } else {
+            /* Read of a global name. In our language, the only global names are functions. */
+            return new SLFunctionLiteralNode(src, context.getFunctionRegistry().lookup(nameToken.val));
+        }
+    }
+
+    public SLExpressionNode createStringLiteral(Token literalToken) {
+        /* Remove the trailing and ending " */
+        String literal = literalToken.val;
+        assert literal.length() >= 2 && literal.startsWith("\"") && literal.endsWith("\"");
+        final SourceSection src = srcFromToken(literalToken);
+        literal = literal.substring(1, literal.length() - 1);
+
+        return new SLStringLiteralNode(src, literal);
+    }
+
+    public SLExpressionNode createNumericLiteral(Token literalToken) {
+        final SourceSection src = srcFromToken(literalToken);
+        try {
+            /* Try if the literal is small enough to fit into a long value. */
+            return new SLLongLiteralNode(src, Long.parseLong(literalToken.val));
+        } catch (NumberFormatException ex) {
+            /* Overflow of long value, so fall back to BigInteger. */
+            return new SLBigIntegerLiteralNode(src, new BigInteger(literalToken.val));
+        }
+    }
+
+    public SLExpressionNode createParenExpression(SLExpressionNode expressionNode, int start, int length) {
+        final SourceSection src = source.createSection("()", start, length);
+        return new SLParenExpressionNode(src, expressionNode);
+    }
+
+    /**
+     * Returns an {@link SLReadPropertyNode} for the given parameters.
+     *
+     * @param receiverNode The receiver of the property access
+     * @param nameToken The name of the property being accessed
+     * @return An SLExpressionNode for the given parameters.
+     */
+    public SLExpressionNode createReadProperty(SLExpressionNode receiverNode, Token nameToken) {
+        final int startPos = receiverNode.getSourceSection().getCharIndex();
+        final int endPos = nameToken.charPos + nameToken.val.length();
+        final SourceSection src = source.createSection(".", startPos, endPos - startPos);
+        return SLReadPropertyNode.create(src, receiverNode, nameToken.val);
+    }
+
+    /**
+     * Returns an {@link SLWritePropertyNode} for the given parameters.
+     *
+     * @param receiverNode The receiver object of the property assignment
+     * @param nameToken The name of the property being assigned
+     * @param valueNode The value to be assigned
+     * @return An SLExpressionNode for the given parameters.
+     */
+    public SLExpressionNode createWriteProperty(SLExpressionNode receiverNode, Token nameToken, SLExpressionNode valueNode) {
+        final int start = receiverNode.getSourceSection().getCharIndex();
+        final int length = valueNode.getSourceSection().getCharEndIndex() - start;
+        SourceSection src = source.createSection("=", start, length);
+        return SLWritePropertyNode.create(src, receiverNode, nameToken.val, valueNode);
+    }
+
+    /**
+     * Creates source description of a single token.
+     */
+    private SourceSection srcFromToken(Token token) {
+        return source.createSection(token.val, token.charPos, token.val.length());
+    }
+
+}