WASM: support stack traces

classlib/src/main/java/org/teavm/classlib/java/lang/TClass.java

@@ -21,10 +21,14 @@ import java.util.Map;
 import org.teavm.classlib.impl.DeclaringClassMetadataGenerator;
 import org.teavm.classlib.java.lang.annotation.TAnnotation;
 import org.teavm.classlib.java.lang.reflect.TAnnotatedElement;
+import org.teavm.interop.Address;
+import org.teavm.interop.DelegateTo;
 import org.teavm.platform.Platform;
 import org.teavm.platform.PlatformClass;
 import org.teavm.platform.metadata.ClassResource;
 import org.teavm.platform.metadata.ClassScopedMetadataProvider;
+import org.teavm.runtime.RuntimeClass;
+import org.teavm.runtime.RuntimeJavaObject;
 
 public class TClass<T> extends TObject implements TAnnotatedElement {
     TString name;
@@ -61,6 +65,7 @@ public class TClass<T> extends TObject implements TAnnotatedElement {
         return Platform.isAssignable(obj.getPlatformClass(), platformClass);
     }
 
+    @DelegateTo("getNameLowLevel")
     public TString getName() {
         if (name == null) {
             name = TString.wrap(Platform.getName(platformClass));
@@ -68,6 +73,11 @@ public class TClass<T> extends TObject implements TAnnotatedElement {
         return name;
     }
 
+    private RuntimeJavaObject getNameLowLevel() {
+        RuntimeClass runtimeClass = Address.ofObject(this).toStructure();
+        return runtimeClass.name;
+    }
+
     public TString getSimpleName() {
         if (simpleName == null) {
             if (isArray()) {

classlib/src/main/java/org/teavm/classlib/java/lang/TStackTraceElement.java

@@ -19,10 +19,6 @@ import java.util.Objects;
 import org.teavm.classlib.java.io.TSerializable;
 import org.teavm.classlib.java.util.TObjects;
 
-/**
- *
- * @author Alexey Andreev
- */
 public final class TStackTraceElement extends TObject implements TSerializable {
     private TString declaringClass;
     private TString methodName;
@@ -89,6 +85,7 @@ public final class TStackTraceElement extends TObject implements TSerializable {
         } else {
             sb.append(TString.wrap("Unknown Source"));
         }
+        sb.append(TString.wrap(")"));
         return sb.toString();
     }
 }

classlib/src/main/java/org/teavm/classlib/java/lang/TThrowable.java

@@ -17,9 +17,11 @@ package org.teavm.classlib.java.lang;
 
 import org.teavm.classlib.java.io.TPrintStream;
 import org.teavm.classlib.java.util.TArrays;
+import org.teavm.interop.DelegateTo;
 import org.teavm.interop.Remove;
 import org.teavm.interop.Rename;
 import org.teavm.interop.Superclass;
+import org.teavm.runtime.ExceptionHandling;
 
 @Superclass("java.lang.Object")
 public class TThrowable extends RuntimeException {
@@ -29,6 +31,7 @@ public class TThrowable extends RuntimeException {
     private boolean suppressionEnabled;
     private boolean writableStackTrace;
     private TThrowable[] suppressed = new TThrowable[0];
+    private TStackTraceElement[] stackTrace;
 
     @SuppressWarnings("unused")
     @Rename("fakeInit")
@@ -97,10 +100,18 @@ public class TThrowable extends RuntimeException {
     }
 
     @Override
+    @DelegateTo("fillInStackTraceLowLevel")
     public Throwable fillInStackTrace() {
         return this;
     }
 
+    private TThrowable fillInStackTraceLowLevel() {
+        int stackSize = ExceptionHandling.callStackSize() - 1;
+        stackTrace = new TStackTraceElement[stackSize];
+        ExceptionHandling.fillStackTrace((StackTraceElement[]) (Object) stackTrace, 2);
+        return this;
+    }
+
     @Rename("getMessage")
     public TString getMessage0() {
         return message;
@@ -143,15 +154,25 @@ public class TThrowable extends RuntimeException {
 
     public void printStackTrace(TPrintStream stream) {
         stream.println(TString.wrap(getClass().getName() + ": " + getMessage()));
+        if (stackTrace != null) {
+            for (TStackTraceElement element : stackTrace) {
+                stream.print(TString.wrap("  at "));
+                stream.println(element);
+            }
+        }
+        if (cause != null && cause != this) {
+            stream.print(TString.wrap("Caused by: "));
+            cause.printStackTrace(stream);
+        }
     }
 
     @Rename("getStackTrace")
     public TStackTraceElement[] getStackTrace0() {
-        return new TStackTraceElement[0];
+        return stackTrace != null ? stackTrace.clone() : new TStackTraceElement[0];
     }
 
     public void setStackTrace(@SuppressWarnings("unused") TStackTraceElement[] stackTrace) {
-        // do nothing
+        this.stackTrace = stackTrace.clone();
     }
 
     @Rename("getSuppressed")

core/src/main/java/org/teavm/backend/wasm/WasmTarget.java

@@ -282,7 +282,7 @@ public class WasmTarget implements TeaVMTarget {
 
         Decompiler decompiler = new Decompiler(classes, controller.getClassLoader(), new HashSet<>(),
                 new HashSet<>());
-        WasmStringPool stringPool = new WasmStringPool(classGenerator, binaryWriter);
+        WasmStringPool stringPool = classGenerator.getStringPool();
         WasmGenerationContext context = new WasmGenerationContext(classes, module, controller.getDiagnostics(),
                 vtableProvider, tagRegistry, stringPool);
 
@@ -302,7 +302,7 @@ public class WasmTarget implements TeaVMTarget {
         context.addIntrinsic(mutatorIntrinsic);
         context.addIntrinsic(new ShadowStackIntrinsic());
         ExceptionHandlingIntrinsic exceptionHandlingIntrinsic = new ExceptionHandlingIntrinsic(binaryWriter,
-                classGenerator);
+                classGenerator, stringPool);
         context.addIntrinsic(exceptionHandlingIntrinsic);
 
         WasmGenerator generator = new WasmGenerator(decompiler, classes, context, classGenerator, binaryWriter);

core/src/main/java/org/teavm/backend/wasm/generate/CallSiteBinaryGenerator.java

@@ -16,34 +16,50 @@
 package org.teavm.backend.wasm.generate;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import org.teavm.backend.wasm.binary.BinaryWriter;
 import org.teavm.backend.wasm.binary.DataPrimitives;
 import org.teavm.backend.wasm.binary.DataStructure;
 import org.teavm.backend.wasm.binary.DataValue;
 import org.teavm.model.ValueType;
 import org.teavm.model.lowlevel.CallSiteDescriptor;
+import org.teavm.model.lowlevel.CallSiteLocation;
 import org.teavm.model.lowlevel.ExceptionHandlerDescriptor;
 
 public class CallSiteBinaryGenerator {
     private static final int CALL_SITE_HANDLER_COUNT = 0;
     private static final int CALL_SITE_FIRST_HANDLER = 1;
+    private static final int CALL_SITE_LOCATION = 2;
     private static final int EXCEPTION_HANDLER_ID = 0;
     private static final int EXCEPTION_HANDLER_CLASS = 1;
+    private static final int LOCATION_FILE = 0;
+    private static final int LOCATION_CLASS = 1;
+    private static final int LOCATION_METHOD = 2;
+    private static final int LOCATION_LINE_NUMBER = 3;
 
     private DataStructure callSiteStructure = new DataStructure((byte) 0,
             DataPrimitives.INT,
+            DataPrimitives.ADDRESS,
             DataPrimitives.ADDRESS);
     private DataStructure exceptionHandlerStructure = new DataStructure((byte) 0,
             DataPrimitives.INT,
             DataPrimitives.ADDRESS);
+    private DataStructure locationStructure = new DataStructure((byte) 0,
+            DataPrimitives.ADDRESS,
+            DataPrimitives.ADDRESS,
+            DataPrimitives.ADDRESS,
+            DataPrimitives.INT);
 
     private BinaryWriter writer;
     private WasmClassGenerator classGenerator;
+    private WasmStringPool stringPool;
 
-    public CallSiteBinaryGenerator(BinaryWriter writer, WasmClassGenerator classGenerator) {
+    public CallSiteBinaryGenerator(BinaryWriter writer, WasmClassGenerator classGenerator, WasmStringPool stringPool) {
         this.writer = writer;
         this.classGenerator = classGenerator;
+        this.stringPool = stringPool;
     }
 
     public int writeCallSites(List<CallSiteDescriptor> callSites) {
@@ -53,7 +69,7 @@ public class CallSiteBinaryGenerator {
 
         int firstCallSite = -1;
         List<DataValue> binaryCallSites = new ArrayList<>();
-        for (CallSiteDescriptor callSite : callSites) {
+        for (int i = 0; i < callSites.size(); i++) {
             DataValue binaryCallSite = callSiteStructure.createValue();
             int address = writer.append(binaryCallSite);
             if (firstCallSite < 0) {
@@ -62,6 +78,8 @@ public class CallSiteBinaryGenerator {
             binaryCallSites.add(binaryCallSite);
         }
 
+        Map<CallSiteLocation, Integer> locationCache = new HashMap<>();
+
         for (int callSiteId = 0; callSiteId < callSites.size(); ++callSiteId) {
             DataValue binaryCallSite = binaryCallSites.get(callSiteId);
             CallSiteDescriptor callSite = callSites.get(callSiteId);
@@ -91,6 +109,23 @@ public class CallSiteBinaryGenerator {
                     binaryExceptionHandler.setAddress(EXCEPTION_HANDLER_CLASS, classPointer);
                 }
             }
+
+            int locationAddress = locationCache.computeIfAbsent(callSite.getLocation(), location -> {
+                DataValue binaryLocation = locationStructure.createValue();
+                int address = writer.append(binaryLocation);
+                if (location.getFileName() != null) {
+                    binaryLocation.setAddress(LOCATION_FILE, stringPool.getStringPointer(location.getFileName()));
+                }
+                if (location.getClassName() != null) {
+                    binaryLocation.setAddress(LOCATION_CLASS, stringPool.getStringPointer(location.getClassName()));
+                }
+                if (location.getMethodName() != null) {
+                    binaryLocation.setAddress(LOCATION_METHOD, stringPool.getStringPointer(location.getMethodName()));
+                }
+                binaryLocation.setInt(LOCATION_LINE_NUMBER, location.getLineNumber());
+                return address;
+            });
+            binaryCallSite.setAddress(CALL_SITE_LOCATION, locationAddress);
         }
 
         return firstCallSite;

core/src/main/java/org/teavm/backend/wasm/generate/WasmClassGenerator.java

@@ -57,6 +57,7 @@ public class WasmClassGenerator {
     private List<String> functionTable = new ArrayList<>();
     private VirtualTableProvider vtableProvider;
     private TagRegistry tagRegistry;
+    private WasmStringPool stringPool;
     private DataStructure objectStructure = new DataStructure((byte) 0,
             DataPrimitives.INT, /* class */
             DataPrimitives.ADDRESS /* monitor/hash code */);
@@ -67,6 +68,7 @@ public class WasmClassGenerator {
             DataPrimitives.INT, /* flags */
             DataPrimitives.INT, /* tag */
             DataPrimitives.INT, /* canary */
+            DataPrimitives.ADDRESS, /* name */
             DataPrimitives.ADDRESS, /* item type */
             DataPrimitives.ADDRESS, /* array type */
             DataPrimitives.INT, /* isInstance function */
@@ -79,11 +81,12 @@ public class WasmClassGenerator {
     private static final int CLASS_FLAGS = 2;
     private static final int CLASS_TAG = 3;
     private static final int CLASS_CANARY = 4;
-    private static final int CLASS_ITEM_TYPE = 5;
+    private static final int CLASS_NAME = 5;
-    private static final int CLASS_ARRAY_TYPE = 6;
+    private static final int CLASS_ITEM_TYPE = 6;
-    private static final int CLASS_IS_INSTANCE = 7;
+    private static final int CLASS_ARRAY_TYPE = 7;
-    private static final int CLASS_PARENT = 8;
+    private static final int CLASS_IS_INSTANCE = 8;
-    private static final int CLASS_LAYOUT = 9;
+    private static final int CLASS_PARENT = 9;
+    private static final int CLASS_LAYOUT = 10;
 
     public WasmClassGenerator(ClassReaderSource classSource, VirtualTableProvider vtableProvider,
             TagRegistry tagRegistry, BinaryWriter binaryWriter) {
@@ -91,6 +94,11 @@ public class WasmClassGenerator {
         this.vtableProvider = vtableProvider;
         this.tagRegistry = tagRegistry;
         this.binaryWriter = binaryWriter;
+        this.stringPool = new WasmStringPool(this, binaryWriter);
+    }
+
+    public WasmStringPool getStringPool() {
+        return stringPool;
     }
 
     private void addClass(ValueType type) {
@@ -204,6 +212,7 @@ public class WasmClassGenerator {
         int tag = ranges.stream().mapToInt(range -> range.lower).min().orElse(0);
         header.setInt(CLASS_TAG, tag);
         header.setInt(CLASS_CANARY, RuntimeClass.computeCanary(occupiedSize, tag));
+        header.setAddress(CLASS_NAME, stringPool.getStringPointer(name));
         header.setInt(CLASS_IS_INSTANCE, functionTable.size());
         functionTable.add(WasmMangling.mangleIsSupertype(ValueType.object(name)));
         header.setAddress(CLASS_PARENT, parentPtr);

core/src/main/java/org/teavm/backend/wasm/intrinsics/ExceptionHandlingIntrinsic.java

@@ -21,6 +21,7 @@ import org.teavm.ast.InvocationExpr;
 import org.teavm.backend.wasm.binary.BinaryWriter;
 import org.teavm.backend.wasm.generate.CallSiteBinaryGenerator;
 import org.teavm.backend.wasm.generate.WasmClassGenerator;
+import org.teavm.backend.wasm.generate.WasmStringPool;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
 import org.teavm.backend.wasm.model.expression.WasmIntBinary;
@@ -28,14 +29,18 @@ import org.teavm.backend.wasm.model.expression.WasmIntBinaryOperation;
 import org.teavm.backend.wasm.model.expression.WasmIntType;
 import org.teavm.model.MethodReference;
 import org.teavm.model.lowlevel.CallSiteDescriptor;
+import org.teavm.runtime.CallSite;
 import org.teavm.runtime.ExceptionHandling;
 
 public class ExceptionHandlingIntrinsic implements WasmIntrinsic {
     private CallSiteBinaryGenerator callSiteBinaryGenerator;
+    private WasmClassGenerator classGenerator;
     private List<WasmInt32Constant> constants = new ArrayList<>();
 
-    public ExceptionHandlingIntrinsic(BinaryWriter binaryWriter, WasmClassGenerator classGenerator) {
+    public ExceptionHandlingIntrinsic(BinaryWriter binaryWriter, WasmClassGenerator classGenerator,
-        callSiteBinaryGenerator = new CallSiteBinaryGenerator(binaryWriter, classGenerator);
+            WasmStringPool stringPool) {
+        callSiteBinaryGenerator = new CallSiteBinaryGenerator(binaryWriter, classGenerator, stringPool);
+        this.classGenerator = classGenerator;
     }
 
     @Override
@@ -63,9 +68,10 @@ public class ExceptionHandlingIntrinsic implements WasmIntrinsic {
         constant.setLocation(invocation.getLocation());
         constants.add(constant);
 
+        int callSiteSize = classGenerator.getClassSize(CallSite.class.getName());
         WasmExpression id = manager.generate(invocation.getArguments().get(0));
-        WasmExpression offset = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.SHL,
+        WasmExpression offset = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.MUL,
-                id, new WasmInt32Constant(3));
+                id, new WasmInt32Constant(callSiteSize));
 
         return new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.ADD, constant, offset);
     }

core/src/main/java/org/teavm/model/lowlevel/CallSiteDescriptor.java

@@ -21,15 +21,21 @@ import java.util.List;
 public class CallSiteDescriptor {
     private int id;
     private List<ExceptionHandlerDescriptor> handlers = new ArrayList<>();
+    private CallSiteLocation location;
 
-    public CallSiteDescriptor(int id) {
+    public CallSiteDescriptor(int id, CallSiteLocation location) {
         this.id = id;
+        this.location = location;
     }
 
     public int getId() {
         return id;
     }
 
+    public CallSiteLocation getLocation() {
+        return location;
+    }
+
     public List<ExceptionHandlerDescriptor> getHandlers() {
         return handlers;
     }

core/src/main/java/org/teavm/model/lowlevel/CallSiteLocation.java

@@ -0,0 +1,66 @@
+/*
+ *  Copyright 2017 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.model.lowlevel;
+
+import java.util.Objects;
+
+public class CallSiteLocation {
+    private String fileName;
+    private String className;
+    private String methodName;
+    private int lineNumber;
+
+    public CallSiteLocation(String fileName, String className, String methodName, int lineNumber) {
+        this.fileName = fileName;
+        this.className = className;
+        this.methodName = methodName;
+        this.lineNumber = lineNumber;
+    }
+
+    public String getFileName() {
+        return fileName;
+    }
+
+    public String getClassName() {
+        return className;
+    }
+
+    public String getMethodName() {
+        return methodName;
+    }
+
+    public int getLineNumber() {
+        return lineNumber;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof CallSiteLocation)) {
+            return false;
+        }
+        CallSiteLocation other = (CallSiteLocation) obj;
+        return Objects.equals(fileName, other.fileName) && Objects.equals(className, other.className)
+                && Objects.equals(methodName, other.methodName) && lineNumber == other.lineNumber;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(fileName, className, methodName, lineNumber);
+    }
+}

core/src/main/java/org/teavm/model/lowlevel/ExceptionHandlingShadowStackContributor.java

@@ -190,7 +190,11 @@ public class ExceptionHandlingShadowStackContributor {
                     }
                 }
 
-                CallSiteDescriptor callSite = new CallSiteDescriptor(callSites.size());
+                String fileName = insn.getLocation() != null ? insn.getLocation().getFileName() : null;
+                int lineNumber = insn.getLocation() != null ? insn.getLocation().getLine() : -1;
+                CallSiteLocation location = new CallSiteLocation(fileName, method.getClassName(), method.getName(),
+                        lineNumber);
+                CallSiteDescriptor callSite = new CallSiteDescriptor(callSites.size(), location);
                 callSites.add(callSite);
                 List<Instruction> pre = setLocation(getInstructionsBeforeCallSite(callSite), insn.getLocation());
                 List<Instruction> post = getInstructionsAfterCallSite(block, next, callSite, currentJointSources);

core/src/main/java/org/teavm/runtime/CallSite.java

@@ -24,4 +24,5 @@ import org.teavm.interop.Unmanaged;
 public class CallSite extends Structure {
     public int handlerCount;
     public ExceptionHandler firstHandler;
+    public CallSiteLocation location;
 }

core/src/main/java/org/teavm/runtime/CallSiteLocation.java

@@ -0,0 +1,25 @@
+/*
+ *  Copyright 2017 Alexey Andreev.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.teavm.runtime;
+
+import org.teavm.interop.Structure;
+
+public class CallSiteLocation extends Structure {
+    public String fileName;
+    public String className;
+    public String methodName;
+    public int lineNumber;
+}

core/src/main/java/org/teavm/runtime/ExceptionHandling.java

@@ -21,7 +21,6 @@ import org.teavm.interop.StaticInit;
 import org.teavm.interop.Structure;
 import org.teavm.interop.Unmanaged;
 
-@Unmanaged
 @StaticInit
 public final class ExceptionHandling {
     private ExceptionHandling() {
@@ -32,12 +31,14 @@ public final class ExceptionHandling {
     private static Throwable thrownException;
 
     @Export(name = "sys$catchException")
+    @Unmanaged
     public static Throwable catchException() {
         Throwable exception = thrownException;
         thrownException = null;
         return exception;
     }
 
+    @Unmanaged
     public static void throwException(Throwable exception) {
         thrownException = exception;
 
@@ -64,4 +65,41 @@ public final class ExceptionHandling {
             stackFrame = ShadowStack.getNextStackFrame(stackFrame);
         }
     }
+
+    @Unmanaged
+    public static int callStackSize() {
+        Address stackFrame = ShadowStack.getStackTop();
+        int size = 0;
+        while (stackFrame != null) {
+            stackFrame = ShadowStack.getNextStackFrame(stackFrame);
+            size++;
+        }
+        return size;
+    }
+
+    @Unmanaged
+    public static void fillStackTrace(StackTraceElement[] target, int skip) {
+        Address stackFrame = ShadowStack.getNextStackFrame(ShadowStack.getNextStackFrame(ShadowStack.getStackTop()));
+        int index = 0;
+        while (stackFrame != null && index < target.length) {
+            int callSiteId = ShadowStack.getCallSiteId(stackFrame);
+            CallSite callSite = findCallSiteById(callSiteId);
+            CallSiteLocation location = callSite.location;
+            StackTraceElement element = createElement(location != null ? location.className : "",
+                    location != null ? location.methodName : "", location != null ? location.fileName : null,
+                    location != null ? location.lineNumber : -1);
+            if (skip > 0) {
+                skip--;
+            } else {
+                target[index++] = element;
+            }
+
+            stackFrame = ShadowStack.getNextStackFrame(stackFrame);
+        }
+    }
+
+    private static StackTraceElement createElement(String className, String methodName, String fileName,
+            int lineNumber) {
+        return new StackTraceElement(className, methodName, fileName, lineNumber);
+    }
 }

core/src/main/java/org/teavm/runtime/RuntimeClass.java

@@ -26,6 +26,7 @@ public class RuntimeClass extends RuntimeJavaObject {
     public int flags;
     public int tag;
     public int canary;
+    public RuntimeJavaObject name;
     public RuntimeClass itemType;
     public RuntimeClass arrayType;
     public IsSupertypeFunction isSupertypeOf;

platform/src/main/java/org/teavm/platform/Platform.java

@@ -172,7 +172,6 @@ public final class Platform {
         return cls.itemType;
     }
 
-    @DelegateTo("getNameLowLevel")
     public static String getName(PlatformClass cls) {
         return cls.getMetadata().getName();
     }