debug tests: Introduce line "tags" to avoid hardcoding line numbers

Hardcoding line numbers in tests make it a pain to modify the test sources.
The approach adopted in the gdb testsuite is to look for a specific string
in the source file and return the line number where it is found. I made a
similar system for the CDT debug tests.

I dubbed this system breakpoint tags, a tag being the string we look for in
the source file.

I modified the MIRunControlTest as an example, as well as GDBProcessesTest
and MIRegistersTest because they are re-using the same breakpoints.

SOURCE_PATH and EXEC_PATH were duplicated in many test cases, so I factored
them in BaseTestCase.

Change-Id: Id1e64b2064914005ab1d87e16704866aa1c8b9ec
Signed-off-by: Simon Marchi <simon.marchi@polymtl.ca>
Reviewed-on: https://git.eclipse.org/r/36872
Tested-by: Hudson CI
Reviewed-by: Elena Laskavaia <elaskavaia.cdt@gmail.com>

dsf-gdb/org.eclipse.cdt.tests.dsf.gdb/src/org/eclipse/cdt/tests/dsf/gdb/framework/BaseTestCase.java

@@ -12,11 +12,16 @@
 package org.eclipse.cdt.tests.dsf.gdb.framework;
 
 import java.io.BufferedReader;
+import java.io.FileReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.Reader;
+import java.util.Arrays;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
+import java.util.NoSuchElementException;
+import java.util.Set;
 
 import org.eclipse.cdt.debug.core.ICDTLaunchConfigurationConstants;
 import org.eclipse.cdt.dsf.datamodel.IDMEvent;
@@ -66,6 +71,12 @@ import org.junit.rules.Timeout;
  */
 @SuppressWarnings("restriction")
 public class BaseTestCase {
+	/*
+	 * Path to executable
+	 */
+	protected static final String EXEC_PATH = "data/launch/bin/";
+	protected static final String SOURCE_PATH = "data/launch/src/";
+
 	// Timeout value for each individual test
 	private final static int TEST_TIMEOUT = 5 * 60 * 1000; // 5 minutes in milliseconds
 	
@@ -103,6 +114,8 @@ public class BaseTestCase {
 
 	private static boolean fgStatusHandlersEnabled = true;
 
+	private static HashMap<String, Integer> fTagLocations = new HashMap<>();
+
     public GdbLaunch getGDBLaunch() { return fLaunch; }
     
     public void setLaunchAttribute(String key, Object value) { 
@@ -197,8 +210,8 @@ public class BaseTestCase {
 		setLaunchAttributes();
 		doLaunch();
 	}
-	
-    protected void setLaunchAttributes() {
+
+	protected void setLaunchAttributes() {
     	// Clear all launch attributes before starting a new test
     	launchAttributes = new HashMap<String, Object>();
     	
@@ -225,6 +238,64 @@ public class BaseTestCase {
     	launchAttributes.putAll(globalLaunchAttributes);
     }
 
+	/**
+	 * Given a set of tags (strings) to find in sourceFile, populate the
+	 * fTagLocations map with the line numbers where they are found.
+	 *
+	 * @param sourceName The path of the source file, relative to {@link #SOURCE_PATH}.
+	 * @param tags Strings to find in sourceFile.
+	 * @throws IOException If sourceFile is not found or can't be read.
+	 * @throws RuntimeException If one or more tags are not found in sourceFile.
+	 */
+	protected void resolveLineTagLocations(String sourceName,
+			String... tags) throws IOException {
+		try (BufferedReader reader =
+				new BufferedReader(new FileReader(SOURCE_PATH + sourceName))) {
+			Set<String> tagsToFind = new HashSet<>(Arrays.asList(tags));
+			String line;
+			int lineNumber = 1;
+
+			fTagLocations.clear();
+
+			line = reader.readLine();
+			while (line != null) {
+				for (String tag : tagsToFind) {
+					if (line.contains(tag)) {
+						fTagLocations.put(tag, lineNumber);
+						tagsToFind.remove(tag);
+						break;
+					}
+				}
+
+				lineNumber++;
+				line = reader.readLine();
+			}
+
+			/* Make sure all tags have been found */
+			if (tagsToFind.size() > 0) {
+				throw new RuntimeException(
+						"Some tags were not found in " + sourceName);
+			}
+		}
+	}
+
+	/**
+	 * Get the source line number that contains the specified tag. In order to
+	 * get an interesting result, {@link #resolveLineTagLocations} must be
+	 * called prior to calling this function.
+	 *
+	 * @param tag Tag for which to get the source line.
+	 * @return The line number corresponding to tag.
+	 * @throws NoSuchElementException if the tag does not exist.
+	 */
+	protected int getLineForTag(String tag) {
+		if (!fTagLocations.containsKey(tag)) {
+			throw new NoSuchElementException("tag " + tag);
+		}
+
+		return fTagLocations.get(tag);
+	}
+
     /**
      * Launch GDB.  The launch attributes must have been set already.
      */

dsf-gdb/org.eclipse.cdt.tests.dsf.gdb/src/org/eclipse/cdt/tests/dsf/gdb/tests/GDBProcessesTest.java

@@ -40,10 +40,6 @@ import org.junit.runner.RunWith;
 
 @RunWith(BackgroundRunner.class)
 public class GDBProcessesTest extends BaseTestCase {
-	/*
-	 * Path to executable
-	 */
-	private static final String EXEC_PATH = "data/launch/bin/";
 	/*
 	 * Name of the executable
 	 */
@@ -64,7 +60,9 @@ public class GDBProcessesTest extends BaseTestCase {
     @Override
 	public void doBeforeTest() throws Exception {
 		super.doBeforeTest();
-		
+
+		resolveLineTagLocations(SOURCE_NAME, MIRunControlTest.LINE_TAGS);
+
 	    fSession = getGDBLaunch().getSession();
         Runnable runnable = new Runnable() {
             @Override
@@ -153,7 +151,7 @@ public class GDBProcessesTest extends BaseTestCase {
 	@Test
 	public void getThreadData() throws Throwable {
 		// Start all threads, stop when they are all started
-		SyncUtil.runToLine(SOURCE_NAME, MIRunControlTest.LINE_MAIN_ALL_THREADS_STARTED);
+		SyncUtil.runToLine(SOURCE_NAME, getLineForTag("LINE_MAIN_ALL_THREADS_STARTED"));
 
 		IThreadDMData mainThreadData = SyncUtil.getThreadData(1);
 

dsf-gdb/org.eclipse.cdt.tests.dsf.gdb/src/org/eclipse/cdt/tests/dsf/gdb/tests/MIBreakpointsTest.java

@@ -79,7 +79,6 @@ public class MIBreakpointsTest extends BaseTestCase {
     // Global constants
     public static final String PLUGIN_ID   = "org.eclipse.cdt.debug.core" ; //$NON-NLS-1$
     public static final String TEST_APPL   = "data/launch/bin/BreakpointTestApp.exe"; //$NON-NLS-1$
-    public static final String SOURCE_PATH = "data/launch/src"; //$NON-NLS-1$
 
     public static final String SOURCE_PROJECT = "MIBreakpointsTest";
     public static final String SOURCE_FOLDER  = "src";

dsf-gdb/org.eclipse.cdt.tests.dsf.gdb/src/org/eclipse/cdt/tests/dsf/gdb/tests/MIRegistersTest.java

@@ -116,16 +116,11 @@ public class MIRegistersTest extends BaseTestCase {
 		return fRegisterNames;
 	}
 
-	/*
-	 * Path to executable
-	 */
-	private static final String EXEC_PATH = "data/launch/bin/";
-
 	/*
 	 * Name of the executable
 	 */
 	private static final String EXEC_NAME = "MultiThread.exe";
-	private static final String SRC_NAME = "MultiThread.cc";
+	private static final String SOURCE_NAME = "MultiThread.cc";
 
 	private static final String GROUP_X = "GroupX";
 	private static final String GROUP_Y = "GroupY";
@@ -143,6 +138,7 @@ public class MIRegistersTest extends BaseTestCase {
 		super.doBeforeTest();
 
 		fSession = getGDBLaunch().getSession();
+		resolveLineTagLocations(SOURCE_NAME, MIRunControlTest.LINE_TAGS);
 
 		Runnable runnable = new Runnable() {
 			@Override
@@ -368,7 +364,8 @@ public class MIRegistersTest extends BaseTestCase {
 
 	@Test
 	public void compareRegisterForMultipleExecutionContexts() throws Throwable {
-		MIStoppedEvent stoppedEvent = SyncUtil.runToLine(SRC_NAME, MIRunControlTest.LINE_MAIN_ALL_THREADS_STARTED);
+		MIStoppedEvent stoppedEvent = SyncUtil.runToLine(SOURCE_NAME,
+				getLineForTag("LINE_MAIN_ALL_THREADS_STARTED"));
 
 		// Get the thread IDs
 		final IContainerDMContext containerDmc = DMContexts.getAncestorOfType(stoppedEvent.getDMContext(), IContainerDMContext.class);

dsf-gdb/org.eclipse.cdt.tests.dsf.gdb/src/org/eclipse/cdt/tests/dsf/gdb/tests/MIRunControlTest.java

@@ -85,15 +85,12 @@ public class MIRunControlTest extends BaseTestCase {
 	private IContainerDMContext fContainerDmc;
 	private IExecutionDMContext fThreadExecDmc;
 
-	// line numbers in MultiThread.cc
-	static final int LINE_MAIN_BEFORE_THREAD_START = 75; // Just before StartThread
-	static final int LINE_MAIN_AFTER_THREAD_START = 86; // Just after StartThread, where the thread is guaranteed to be started.
-	static final int LINE_MAIN_ALL_THREADS_STARTED = 92; // Where all threads are guaranteed to be started.
-
-	/*
-	 * Path to executable
-	 */
-	private static final String EXEC_PATH = "data/launch/bin/";
+	// Breakpoint tags in MultiThread.cc
+	public static final String[] LINE_TAGS = new String[] {
+			"LINE_MAIN_BEFORE_THREAD_START", // Just before StartThread
+			"LINE_MAIN_AFTER_THREAD_START", // Just after StartThread
+			"LINE_MAIN_ALL_THREADS_STARTED", // Where all threads are guaranteed to be started.
+	};
 
 	/*
 	 * Name of the executable
@@ -104,7 +101,9 @@ public class MIRunControlTest extends BaseTestCase {
 	@Override
 	public void doBeforeTest() throws Exception {
 		super.doBeforeTest();
-		
+
+		resolveLineTagLocations(SOURCE_NAME, LINE_TAGS);
+
 		final DsfSession session = getGDBLaunch().getSession();
 		
         Runnable runnable = new Runnable() {
@@ -275,7 +274,11 @@ public class MIRunControlTest extends BaseTestCase {
             		getGDBLaunch().getSession(),
             		IStartedDMEvent.class);
 
-        SyncUtil.runToLine(fContainerDmc, SOURCE_NAME, LINE_MAIN_AFTER_THREAD_START, true);
+		SyncUtil.runToLine(
+				fContainerDmc,
+				SOURCE_NAME,
+				getLineForTag("LINE_MAIN_AFTER_THREAD_START"),
+				true);
 
         final IContainerDMContext containerDmc = SyncUtil.getContainerContext();
         
@@ -426,7 +429,8 @@ public class MIRunControlTest extends BaseTestCase {
 		/* 
 		 * Add a breakpoint
 		 */
-	    SyncUtil.addBreakpoint(SOURCE_NAME + ":" + LINE_MAIN_BEFORE_THREAD_START, false);
+		SyncUtil.addBreakpoint(SOURCE_NAME + ":"
+				+ getLineForTag("LINE_MAIN_BEFORE_THREAD_START"), false);
 		
 		/*
 		 * Resume till the breakpoint is hit
@@ -681,7 +685,7 @@ public class MIRunControlTest extends BaseTestCase {
 			@Override
 			public void run() {
 				fRunCtrl.runToLine(fThreadExecDmc, SOURCE_NAME,
-						LINE_MAIN_ALL_THREADS_STARTED, true,
+						getLineForTag("LINE_MAIN_ALL_THREADS_STARTED"), true,
 						new RequestMonitor(fRunCtrl.getExecutor(), null) {
 							@Override
 							protected void handleCompleted() {