tracesrv/tracecompiler/src/com.nokia.tracecompiler/src/com/nokia/tracecompiler/source/FunctionReturnValueParser.java
changeset 56 aa2539c91954
parent 41 838cdffd57ce
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tracesrv/tracecompiler/src/com.nokia.tracecompiler/src/com/nokia/tracecompiler/source/FunctionReturnValueParser.java	Fri Oct 08 14:56:39 2010 +0300
@@ -0,0 +1,317 @@
+/*
+* Copyright (c) 2007 Nokia Corporation and/or its subsidiary(-ies). 
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+* Parser for function return values
+*
+*/
+package com.nokia.tracecompiler.source;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Parser for function return values
+ * 
+ */
+class FunctionReturnValueParser {
+
+	/**
+	 * Source parser
+	 */
+	private SourceParser parser;
+
+	/**
+	 * Comparator for source return values
+	 */
+	private PositionArrayComparator comparator = new PositionArrayComparator();
+
+	/**
+	 * Macros representing return statement
+	 */
+	private List<String> returnExtensions;
+
+	/**
+	 * Constructor
+	 * 
+	 * @param parser
+	 *            the source parser
+	 */
+	FunctionReturnValueParser(SourceParser parser) {
+		this.parser = parser;
+	}
+
+	/**
+	 * Parses the return values of given source context
+	 * 
+	 * @param context
+	 *            the context to be parsed
+	 * @param list
+	 *            the list of return values
+	 */
+	void parseReturnValues(SourceContext context, List<SourceReturn> list) {
+		String statement = SourceConstants.RETURN;
+		try {
+			parseReturnValues(context, list, statement);
+		} catch (SourceParserException e) {
+		}
+		if (returnExtensions != null && returnExtensions.size() > 0) {
+			for (int i = 0; i < returnExtensions.size(); i++) {
+				try {
+					parseReturnValues(context, list, returnExtensions.get(i));
+				} catch (SourceParserException e) {
+				}
+			}
+			Collections.sort(list, comparator);
+		}
+		if (context.isVoid()) {
+			boolean addToEnd = true;
+			// If there were no return statements, the trace is added to end
+			// Otherwise the last return statement needs to be checked. If it is
+			// at the end of the function, the return trace is not added to
+			// the end
+			if (!list.isEmpty()) {
+				SourceReturn ret = list.get(list.size() - 1);
+				SourceIterator itr = parser.createIterator(ret.getOffset()
+						+ ret.getLength() + 1, SourceParser.SKIP_ALL);
+				try {
+					itr.next();
+					// If the next character after return statement is the end
+					// of function, the return is not added
+					if (itr.currentIndex() == context.getOffset()
+							+ context.getLength() - 1) {
+						addToEnd = false;
+					}
+				} catch (SourceParserException e) {
+					addToEnd = false;
+				}
+			}
+			if (addToEnd) {
+				list.add(new SourceReturn(parser, context.getOffset()
+						+ context.getLength() - 1, 0));
+			}
+		}
+	}
+
+	/**
+	 * Parses the return values of given source context that use the given
+	 * return statement
+	 * 
+	 * @param context
+	 *            the context to be parsed
+	 * @param list
+	 *            the list of return values
+	 * @param statement
+	 *            the return statement
+	 * @throws SourceParserException
+	 *             if processing fails
+	 */
+	private void parseReturnValues(SourceContext context,
+			List<SourceReturn> list, String statement)
+			throws SourceParserException {
+		FunctionReturnValueSearchData data = new FunctionReturnValueSearchData();
+		int offset = context.getOffset();
+		int end = offset + context.getLength();
+		SourceSearch search = parser.startStringSearch(statement, offset, end,
+				SourceParser.MATCH_WHOLE_WORD | SourceParser.SKIP_ALL);
+		boolean looping = true;
+		do {
+			data.index = search.findNext();
+			if (data.index != -1) {
+				data.itr = parser.createIterator(data.index
+						+ statement.length(), SourceParser.SKIP_ALL);
+				locateReturnStatement(data);
+				if (data.endOffset != -1 && data.startOffset != -1) {
+					SourceReturn ret = createReturnStatement(data);
+					list.add(ret);
+				} else {
+					// End of return statement missing
+					looping = false;
+				}
+			} else {
+				looping = false;
+			}
+		} while (looping);
+	}
+
+	/**
+	 * Locates the start and end offsets for the return statement
+	 * 
+	 * @param data
+	 *            the search data
+	 * @throws SourceParserException
+	 *             if parser fails
+	 */
+	private void locateReturnStatement(FunctionReturnValueSearchData data)
+			throws SourceParserException {
+		data.startOffset = -1;
+		data.endOffset = -1;
+		boolean found = false;
+		boolean colonAllowed = false;
+		while (data.itr.hasNext() && !found) {
+			char c = data.itr.next();
+			if (c == ';') {
+				data.endOffset = data.itr.previousIndex() + 1;
+				found = true;
+			} else if (c == '}') {
+				found = true;
+			} else if (c == '?') {
+				colonAllowed = true;
+			} else if (c == ':') {
+				if (data.itr.hasNext() && data.itr.peek() == ':') {
+					// Skips over ::
+					c = data.itr.next();
+				} else {
+					if (colonAllowed) {
+						colonAllowed = false;
+					} else {
+						data.endOffset = data.itr.previousIndex() + 1;
+						found = true;
+					}
+				}
+			}
+			if (data.startOffset == -1) {
+				data.startOffset = data.itr.currentIndex();
+			}
+		}
+	}
+
+	/**
+	 * Creates a return statement
+	 * 
+	 * @param data
+	 *            the parser data
+	 * @return the new statement
+	 * @throws SourceParserException
+	 *             if parser fails
+	 */
+	private SourceReturn createReturnStatement(
+			FunctionReturnValueSearchData data) throws SourceParserException {
+		SourceReturn ret = new SourceReturn(parser, data.startOffset,
+				data.endOffset - data.startOffset);
+		if (checkTag(data.startOffset, data.endOffset - data.startOffset)) {
+			ret.setTagHazard();
+		}
+		if (checkPreviousChar(data.index - 1)) {
+			ret.setPreviousCharHazard();
+		}
+		return ret;
+	}
+
+	/**
+	 * Checks if the tag is hazardous
+	 * 
+	 * @param start
+	 *            start offset
+	 * @param length
+	 *            tag length
+	 * @return true if there is a problem
+	 */
+	private boolean checkTag(int start, int length) {
+		boolean hazard = false;
+		boolean previous = false;
+		// Function calls and increment / decrement operators are not safe
+		for (int i = start; i < start + length && !hazard; i++) {
+			char c = parser.getData(i);
+			if (c == '(') {
+				// If return statement is within brackets, it is not hazardous
+				if (i != start || parser.getData(start + length - 1) != ')') {
+					hazard = true;
+				}
+			} else if (c == '?') {
+				hazard = true;
+			} else if (c == '-' || c == '+') {
+				if (previous) {
+					hazard = true;
+				} else {
+					previous = true;
+				}
+			} else {
+				previous = false;
+			}
+		}
+		return hazard;
+	}
+
+	/**
+	 * Checks if previous character is hazardous
+	 * 
+	 * @param index
+	 *            the index
+	 * @return true if hazard, false if not
+	 * @throws SourceParserException
+	 *             if processing fails
+	 */
+	private boolean checkPreviousChar(int index) throws SourceParserException {
+		boolean hazard = false;
+		SourceIterator previtr = parser.createIterator(index,
+				SourceParser.SKIP_ALL | SourceParser.BACKWARD_SEARCH);
+		char prevchar = previtr.next();
+		if (prevchar != ';' && prevchar != '{' && prevchar != '}') {
+			hazard = true;
+		}
+		return hazard;
+	}
+
+	/**
+	 * Finds the last return statement from the given context
+	 * 
+	 * @param context
+	 *            the context
+	 * @return the index to beginning of the return statement
+	 */
+	int findLast(SourceContext context) {
+		String statement = SourceConstants.RETURN;
+		int retval = findLast(context, statement);
+		if (returnExtensions != null && returnExtensions.size() > 0) {
+			int res;
+			for (int i = 0; i < returnExtensions.size(); i++) {
+				res = findLast(context, returnExtensions.get(i));
+				if (res > retval) {
+					retval = res;
+				}
+			}
+		}
+		if (retval == -1) {
+			retval = context.getOffset() + context.getLength();
+		}
+		return retval;
+	}
+
+	/**
+	 * Finds the last return statement from the given context
+	 * 
+	 * @param context
+	 *            the context
+	 * @param statement
+	 *            the statement to be searched
+	 * @return the index to beginning of the return statement
+	 */
+	private int findLast(SourceContext context, String statement) {
+		// TODO: Backwards string search
+		int start = context.getOffset();
+		int end = start + context.getLength();
+		SourceSearch search = parser.startStringSearch(statement, start, end,
+				SourceParser.MATCH_WHOLE_WORD | SourceParser.SKIP_ALL);
+		int index = 0;
+		int retval = -1;
+		do {
+			index = search.findNext();
+			if (index != -1) {
+				retval = index;
+			}
+		} while (index != -1);
+		return retval;
+	}
+}