Use logback and slf4j to have proper logging in the GdbStub

Author: MaartenS11

build.gradle.kts

@@ -29,6 +29,9 @@ dependencies {
     // Needed for AssemblyScript source mapping:
     //implementation("com.atlassian.sourcemap:sourcemap:2.0.0")
     implementation("com.google.code.gson:gson:2.11.0")
+
+    // Logging
+    implementation("ch.qos.logback:logback-classic:1.5.32")
 }
 
 tasks.test {

src/main/java/be/ugent/topl/mio/GdbStub.java

@@ -4,6 +4,8 @@
 import be.ugent.topl.mio.sourcemap.SourceMap;
 import be.ugent.topl.mio.woodstate.Frame;
 import be.ugent.topl.mio.woodstate.WOODDumpResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.io.*;
 import java.net.ServerSocket;
@@ -19,12 +21,13 @@ public class GdbStub {
     private final Debugger debugger;
     private final String binaryLocation;
     private OutputStream out;
+    private final Logger logger = LoggerFactory.getLogger(GdbStub.class);
     private final SourceMap debugSourceMap; // Remove later, lldb doesn't need this.
 
     public GdbStub(Debugger debugger, String binaryLocation) {
         this.debugger = debugger;
         this.binaryLocation = binaryLocation;
-        debugSourceMap = getDwarfSourcemap(binaryLocation);
+        this.debugSourceMap = getDwarfSourcemap(binaryLocation);
 
         debugger.getBreakpointsListeners().add((pc) -> {
             try {
@@ -82,8 +85,6 @@ private String getTriple(String s) {
         String hex = s.chars()
                 .mapToObj(c -> String.format("%02x", c))
                 .reduce("", String::concat);
-
-        System.out.println(hex);
         return hex;
     }
 
@@ -97,9 +98,9 @@ public void start(int port) throws IOException {
         byte[] wasmData = Files.readAllBytes(Path.of(binaryLocation));
 
         ServerSocket server = new ServerSocket(port);
-        System.out.printf("Waiting for GDB on port %d...", port);
+        logger.info("Waiting for LLDB connection on port {}...", port);
         Socket sock = server.accept();
-        System.out.println("GDB connected!");
+        logger.info("LLDB connected!");
 
         InputStream in = sock.getInputStream();
         out = sock.getOutputStream();
@@ -109,10 +110,10 @@ public void start(int port) throws IOException {
         while (attached) {
             String pkt = recvPacket(in, out);
             if (pkt == null) {
-                System.out.println("GDB closed");
+                logger.info("Connection closed");
                 break;
             }
-            System.out.println("<- " + pkt);
+            logger.trace("<- {}", pkt);
 
             if (pkt.startsWith("m")) {
                 pkt = pkt.substring(1);
@@ -121,7 +122,7 @@ public void start(int port) throws IOException {
                 long addrType = getAddrType(pos);
                 pos = stripAddrType(pos);
                 long len = Long.parseUnsignedLong(memArgs[1], 16);
-                log("Read memory " + len + " bytes from " + pos + " with addr type = " + addrType);
+                logger.info("Read memory {} bytes from {} with addr type = {}", len, pos, addrType);
 
                 // TODO: Hack to temporarily prevent lldb from using breakpoints when stepping
                 //  https://github.com/llvm/llvm-project/issues/189960
@@ -132,7 +133,7 @@ public void start(int port) throws IOException {
 
                 byte[] memory = wasmData;
                 if (addrType == 1) {
-                    log("Reading from wasm linear memory");
+                    logger.info("Reading from wasm linear memory");
                     memory = getCurrentState().getMemory().getBytes();
                 }
                 else {
@@ -141,7 +142,7 @@ public void start(int port) throws IOException {
 
                 // The reply may contain fewer addressable memory units than requested if the server was reading from a trace frame memory and was able to read only part of the region of memory.
                 if (pos >= memory.length || pos < 0) {
-                    System.out.println("Pos " + pos + " out of bounds for length " + memory.length);
+                    logger.warn("Pos {} out of bounds for length {}", pos, memory.length);
                     sendPacket(out, "E01");
                     continue;
                 }
@@ -152,17 +153,13 @@ public void start(int port) throws IOException {
                     // also think about little vs big endian
                     int index = (int) pos + i;
                     if (index >= memory.length) {
-                        System.out.println("Stop reading, out of bounds");
+                        logger.info("Stop reading, out of bounds");
                         break;
                     }
                     int b = memory[index];
                     result.append(String.format("%02x", b & 0xFF));
-                    //result.append("00");
                 }
                 sendPacket(out, result.toString());
-
-                // If memory invalid send E01
-                //sendPacket(out, "E01");
                 continue;
             }
             else if (pkt.startsWith("qSupported")) {
@@ -190,11 +187,11 @@ else if (pkt.startsWith("qWasmLocal:")) {
                 String[] args = pkt.substring("qWasmLocal:".length()).split(";");
                 int frameIdx =  Integer.parseInt(args[0]);
                 int localIdx =  Integer.parseInt(args[1]);
-                log("Reading local " + localIdx + " from frame " + frameIdx);
+                logger.info("Reading local {} from frame {}", localIdx, frameIdx);
                 Frame frame = getCallStack(getCurrentState()).get(frameIdx);
-                System.out.println(getCallStack(getCurrentState()));
-                System.out.println(frame);
-                System.out.println(getCurrentState().getStack());
+                logger.trace("{}", getCallStack(getCurrentState()));
+                logger.trace("{}", frame);
+                logger.trace("{}", getCurrentState().getStack());
                 int fp = frame.getFp();
                 long value = getCurrentState().getStack().get(fp + localIdx + 1).getValue();
                 sendPacket(out, toHex(toWasmAddr(value))); // If a pointer on the stack is an address it will be clear it's a wasm memory pointer.
@@ -213,14 +210,12 @@ else if (pkt.startsWith("Z")) {
                 int type = Integer.parseInt(args[0]);
                 long addr = Long.parseUnsignedLong(args[1], 16);
                 int kind = Integer.parseInt(args[2]);
-                log("Add breakpoint on " + addr);
+                logger.info("Add breakpoint on {}", addr);
                 debugger.addBreakpoint((int) addr);
 
                 try {
-                    for (int i = 0; i < 8; i++) {
-                        log("Breakpoint line " + debugSourceMap.getLineForPc((int) addr + (i-4) * 4) + " " + debugSourceMap.getSourceFileName((int) addr + (i-4) * 4));
-                    }
-                } catch(Exception e) {}
+                    logger.info("Breakpoint line {} {}", debugSourceMap.getLineForPc((int) addr), debugSourceMap.getSourceFileName((int) addr));
+                } catch(Exception _) {}
 
                 // A remote target shall return an empty string for an unrecognized breakpoint or watchpoint packet type.
                 sendPacket(out, "OK");
@@ -232,11 +227,11 @@ else if (pkt.startsWith("z")) {
                 int type = Integer.parseInt(args[0]);
                 long addr = Long.parseUnsignedLong(args[1], 16);
                 int kind = Integer.parseInt(args[2]);
-                log("Remove breakpoint on " + addr);
+                logger.info("Remove breakpoint on {}", addr);
                 debugger.removeBreakpoint((int) addr);
 
                 try {
-                    log("Breakpoint line " + debugSourceMap.getLineForPc((int) addr) + " " + debugSourceMap.getSourceFileName((int) addr));
+                    logger.info("Breakpoint line {} {}", debugSourceMap.getLineForPc((int) addr), debugSourceMap.getSourceFileName((int) addr));
                 } catch(Exception e) {}
 
                 // A remote target shall return an empty string for an unrecognized breakpoint or watchpoint packet type.
@@ -254,8 +249,6 @@ else if (pkt.startsWith("stackInfo")) {
                     sendPacket(out, "OK");
                     break;*/
                 case "qHostInfo":
-                    //sendPacket(out, "triple:x86_64-pc-linux-gnu;endian:little;ptrsize:8;");
-                    //sendPacket(out, "cputype:16777228;cpusubtype:3;ostype:darwin;vendor:apple;endian:little;ptrsize:8;hostname:hello;");
                     sendPacket(out, "vendor:wamr;ostype:wasi;arch:wasm32;endian:little;ptrsize:4;");
                     break;
                 case "qProcessInfo":
@@ -281,7 +274,7 @@ else if (pkt.startsWith("stackInfo")) {
                     sendPacket(out, result);
 
                     try {
-                        log("Current line " + debugSourceMap.getLineForPc(state.getPc()) + " " + debugSourceMap.getSourceFileName(state.getPc()));
+                        logger.info("Current line {} {}", debugSourceMap.getLineForPc(state.getPc()), debugSourceMap.getSourceFileName(state.getPc()));
                     } catch(Exception e) {}
 
                     break;
@@ -301,7 +294,7 @@ else if (pkt.startsWith("stackInfo")) {
                     sendPacket(out, encodeRegs());
                     break;
                 case "s":
-                    log("Received step command from lldb");
+                    logger.info("Received step command from lldb");
                     debugger.stepInto();
                     sendStopPacket(out, "05");
                     break;
@@ -318,12 +311,12 @@ else if (pkt.startsWith("stackInfo")) {
                     break;
                 case "D":
                     attached = false;
-                    log("Detach from target");
+                    logger.info("Detach from target");
                     debugger.close();
                     sendPacket(out, "OK");
                     break;
                 default:
-                    System.out.println("Unknown packet: " + pkt);
+                    logger.warn("Unknown packet: {}", pkt);
                     sendPacket(out, "");
                     break;
             }
@@ -334,13 +327,6 @@ private void sendStopPacket(OutputStream out, String signal) throws IOException
         sendPacket(out, "T" + signal + "thread:1;name:warduino;thread-pcs:" + toHex(getCurrentState().getPc()) + ";00:" + toHex(getCurrentState().getPc()) + ";reason:trace");
     }
 
-    private void log(String s) {
-        System.out.print("\u001b[36m");
-        System.out.print("[GDBSTUB] ");
-        System.out.println(s);
-        System.out.print("\u001b[0m");
-    }
-
     private String recvPacket(InputStream in, OutputStream out) throws IOException {
         int c;
 
@@ -389,7 +375,7 @@ private void sendPacket(OutputStream out, String payload) throws IOException {
         String pkt = "$" + payload + "#" + String.format("%02x", sum);
         out.write(pkt.getBytes());
         out.flush();
-        System.out.println("-> " + pkt);
+        logger.trace("-> {}", pkt);
     }
 
     private int checksum(byte[] data) {