Add logpoint support

Author: LadyCailin

src/main/java/com/laytonsmith/core/environments/Breakpoint.java

@@ -28,6 +28,7 @@ public class Breakpoint {
 	private final ParseTree compiledCondition;
 	private final int hitCountThreshold;
 	private int hitCount;
+	private final String logMessage;
 
 	/**
 	 * Creates an unconditional breakpoint at the given file and line.
@@ -36,7 +37,7 @@ public class Breakpoint {
 	 * @param line The 1-indexed line number. Must be positive.
 	 */
 	public Breakpoint(File file, int line) {
-		this(file, line, null, 0);
+		this(file, line, null, 0, null);
 	}
 
 	/**
@@ -49,9 +50,27 @@ public Breakpoint(File file, int line) {
 	 * @param condition A MethodScript expression to evaluate, or null for unconditional.
 	 * @param hitCountThreshold Number of times the breakpoint must be hit before pausing
 	 *                          (0 means pause on first hit).
-	 * @throws IllegalArgumentException if the condition cannot be compiled
 	 */
 	public Breakpoint(File file, int line, String condition, int hitCountThreshold) {
+		this(file, line, condition, hitCountThreshold, null);
+	}
+
+	/**
+	 * Creates a breakpoint with optional condition, hit count threshold, and log message.
+	 * If a condition is provided, it is compiled immediately so that syntax
+	 * errors are caught early. If a logMessage is provided, this breakpoint
+	 * acts as a log point: instead of pausing, it logs the message and continues.
+	 * Expressions in {@code {braces}} within the log message are evaluated at hit time.
+	 *
+	 * @param file The source file. Must not be null.
+	 * @param line The 1-indexed line number. Must be positive.
+	 * @param condition A MethodScript expression to evaluate, or null for unconditional.
+	 * @param hitCountThreshold Number of times the breakpoint must be hit before pausing
+	 *                          (0 means pause on first hit).
+	 * @param logMessage A message to log instead of pausing, or null for a normal breakpoint.
+	 * @throws IllegalArgumentException if the condition cannot be compiled
+	 */
+	public Breakpoint(File file, int line, String condition, int hitCountThreshold, String logMessage) {
 		if(file == null) {
 			throw new IllegalArgumentException("Breakpoint file must not be null");
 		}
@@ -74,6 +93,21 @@ public Breakpoint(File file, int line, String condition, int hitCountThreshold)
 		} else {
 			this.compiledCondition = null;
 		}
+		this.logMessage = logMessage;
+	}
+
+	/**
+	 * Returns the log message template, or null if this is a normal breakpoint.
+	 */
+	public String logMessage() {
+		return logMessage;
+	}
+
+	/**
+	 * Returns true if this is a log point (logs instead of pausing).
+	 */
+	public boolean isLogPoint() {
+		return logMessage != null && !logMessage.isEmpty();
 	}
 
 	/**

src/main/java/com/laytonsmith/core/environments/DebugContext.java

@@ -81,6 +81,11 @@ public enum ExceptionBreakMode {
 	private ThreadingMode threadingMode;
 	private volatile Thread mainThread;
 
+	// Log point deduplication: tracks last fired log point to avoid firing
+	// multiple times for different AST nodes on the same source line.
+	private File lastLogPointFile;
+	private int lastLogPointLine = -1;
+
 	// Per-thread debug state (step mode, pause latch, etc.)
 	private final ConcurrentHashMap<Thread, ThreadDebugState> threadStates = new ConcurrentHashMap<>();
 
@@ -335,6 +340,24 @@ public boolean shouldPause(Target source, int userCallDepth, Environment env) {
 			} else {
 				shouldStop = true;
 			}
+			if(shouldStop && bp.isLogPoint()) {
+				// Deduplicate: only fire once per visit to a source line.
+				// Resets when execution moves to a different line.
+				if(!source.file().equals(lastLogPointFile) || source.line() != lastLogPointLine) {
+					lastLogPointFile = source.file();
+					lastLogPointLine = source.line();
+					String msg = interpolateLogMessage(bp.logMessage(), env);
+					listener.onLogPoint(msg);
+				}
+				return false;
+			}
+		}
+
+		// Clear log point dedup when we move to a different line
+		if(lastLogPointLine != -1
+				&& (!source.file().equals(lastLogPointFile) || source.line() != lastLogPointLine)) {
+			lastLogPointFile = null;
+			lastLogPointLine = -1;
 		}
 
 		if(!shouldStop) {
@@ -400,6 +423,46 @@ private boolean evaluateBreakpointCondition(Breakpoint bp, Environment env) {
 		return true;
 	}
 
+	/**
+	 * Interpolates a DAP log message template. Expressions in {@code {braces}} are
+	 * evaluated as MethodScript and their string value substituted in.
+	 */
+	private String interpolateLogMessage(String template, Environment env) {
+		StringBuilder sb = new StringBuilder();
+		int i = 0;
+		while(i < template.length()) {
+			char c = template.charAt(i);
+			if(c == '{') {
+				int end = template.indexOf('}', i + 1);
+				if(end == -1) {
+					sb.append(c);
+					i++;
+				} else {
+					String expr = template.substring(i + 1, end);
+					try {
+						Mixed result = MethodScriptCompiler.execute(
+								MethodScriptCompiler.compile(
+										MethodScriptCompiler.lex(expr, null, null, true),
+										null, Environment.getDefaultEnvClasses()),
+								env, null, null);
+						while(result instanceof IVariable iv) {
+							result = env.getEnv(GlobalEnv.class).GetVarList()
+									.get(iv.getVariableName(), iv.getTarget(), env).ival();
+						}
+						sb.append(result.val());
+					} catch(Exception e) {
+						sb.append("{").append(expr).append("}");
+					}
+					i = end + 1;
+				}
+			} else {
+				sb.append(c);
+				i++;
+			}
+		}
+		return sb.toString();
+	}
+
 	/**
 	 * Sets the exception break mode.
 	 *

src/main/java/com/laytonsmith/core/environments/DebugListener.java

@@ -50,4 +50,15 @@ default void onThreadStarted(int dapThreadId, String name) {
 	default void onThreadExited(int dapThreadId) {
 		// no-op by default
 	}
+
+	/**
+	 * Called when a log point breakpoint is hit. The message has already been
+	 * interpolated (expressions in {@code {braces}} evaluated).
+	 * Default implementation does nothing.
+	 *
+	 * @param message The interpolated log message
+	 */
+	default void onLogPoint(String message) {
+		// no-op by default
+	}
 }

src/main/java/com/laytonsmith/core/functions/StringHandling.java

@@ -257,7 +257,7 @@ public ParseTree optimizeDynamic(Target t, Environment env,
 					// sconcat only returns a string (except in the special case above) so we need to
 					// return the string value if it's not already a string
 					try {
-						if(InstanceofUtil.isInstanceof(child.getData(), CString.TYPE, env)) {
+						if(child.isConst() && InstanceofUtil.isInstanceof(child.getData(), CString.TYPE, env)) {
 							return child;
 						}
 					} catch (IllegalArgumentException ex) {

src/main/java/com/laytonsmith/tools/debugger/MSDebugServer.java

@@ -316,6 +316,7 @@ public CompletableFuture<Capabilities> initialize(InitializeRequestArguments arg
 		caps.setSupportsEvaluateForHovers(true);
 		caps.setSupportsConditionalBreakpoints(true);
 		caps.setSupportsHitConditionalBreakpoints(true);
+		caps.setSupportsLogPoints(true);
 
 		ExceptionBreakpointsFilter allFilter = new ExceptionBreakpointsFilter();
 		allFilter.setFilter("all");
@@ -408,6 +409,7 @@ public CompletableFuture<SetBreakpointsResponse> setBreakpoints(SetBreakpointsAr
 			for(SourceBreakpoint sbp : sourceBreakpoints) {
 				String condition = sbp.getCondition();
 				String hitCondition = sbp.getHitCondition();
+				String logMessage = sbp.getLogMessage();
 				int hitThreshold = 0;
 				if(hitCondition != null && !hitCondition.isEmpty()) {
 					try {
@@ -421,7 +423,7 @@ public CompletableFuture<SetBreakpointsResponse> setBreakpoints(SetBreakpointsAr
 				bp.setLine(sbp.getLine());
 				bp.setSource(source);
 				try {
-					debugBps.add(new Breakpoint(file, sbp.getLine(), condition, hitThreshold));
+					debugBps.add(new Breakpoint(file, sbp.getLine(), condition, hitThreshold, logMessage));
 					bp.setVerified(true);
 				} catch(IllegalArgumentException e) {
 					bp.setVerified(false);
@@ -903,5 +905,10 @@ public void onThreadExited(int dapThreadId) {
 				client.thread(args);
 			}
 		}
+
+		@Override
+		public void onLogPoint(String message) {
+			sendOutput("console", message + "\n");
+		}
 	}
 }

src/test/java/com/laytonsmith/core/DebugInfrastructureTest.java

@@ -94,6 +94,7 @@ private Mixed executeWithDebugger(String script, DebugContext debugCtx) throws E
 	 */
 	private static class TestDebugListener implements DebugListener {
 		final List<PausedState> pauses = new ArrayList<>();
+		final List<String> logMessages = new ArrayList<>();
 		boolean completed = false;
 		int resumeCount = 0;
 
@@ -112,6 +113,11 @@ public void onCompleted() {
 			completed = true;
 		}
 
+		@Override
+		public void onLogPoint(String message) {
+			logMessages.add(message);
+		}
+
 		Script.DebugSnapshot snapshot(int index) {
 			return (Script.DebugSnapshot) pauses.get(index);
 		}
@@ -648,4 +654,22 @@ private void dapStepOverNewThread(DebugContext.ThreadingMode mode) throws Except
 					h.awaitStop(2, 5));
 		}
 	}
+
+	@Test
+	public void testLogPoint() throws Exception {
+		String script = "@x = 42\n@y = @x + 1\n@z = @y + 1";
+		TestDebugListener listener = new TestDebugListener();
+		DebugContext debugCtx = new DebugContext(listener, DebugContext.ThreadingMode.ASYNCHRONOUS,
+				Thread.currentThread());
+		debugCtx.addBreakpoint(new Breakpoint(TEST_FILE, 2, null, 0, "x is {@x}"));
+
+		executeWithDebugger(script, debugCtx);
+
+		// Log point should not cause a pause
+		assertEquals(0, listener.pauses.size());
+		// But should have logged the message
+		assertEquals(1, listener.logMessages.size());
+		assertEquals("x is 42", listener.logMessages.get(0));
+		assertTrue(listener.completed);
+	}
 }