WASM: refactoring shadow stack

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

@@ -250,11 +250,11 @@ public final class WasmRuntime {
         return result;
     }
 
-    public static Address getStackGcRoots() {
+    public static Address getStackTop() {
         return stack != initStack() ? stack : null;
     }
 
-    public static Address getNextStackRoots(Address address) {
+    public static Address getNextStackFrame(Address address) {
         int size = address.getInt() + 2;
         Address result = address.add(-size * 4);
         if (result == initStack()) {

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

@@ -38,12 +38,13 @@ import org.teavm.backend.wasm.generate.WasmStringPool;
 import org.teavm.backend.wasm.intrinsics.AddressIntrinsic;
 import org.teavm.backend.wasm.intrinsics.AllocatorIntrinsic;
 import org.teavm.backend.wasm.intrinsics.ClassIntrinsic;
-import org.teavm.backend.wasm.intrinsics.ExceptionHandlingIntrinsic;
 import org.teavm.backend.wasm.intrinsics.FunctionIntrinsic;
 import org.teavm.backend.wasm.intrinsics.GCIntrinsic;
+import org.teavm.backend.wasm.intrinsics.MutatorIntrinsic;
 import org.teavm.backend.wasm.intrinsics.PlatformClassIntrinsic;
 import org.teavm.backend.wasm.intrinsics.PlatformIntrinsic;
 import org.teavm.backend.wasm.intrinsics.PlatformObjectIntrinsic;
+import org.teavm.backend.wasm.intrinsics.ShadowStackIntrinsic;
 import org.teavm.backend.wasm.intrinsics.StructureIntrinsic;
 import org.teavm.backend.wasm.intrinsics.WasmRuntimeIntrinsic;
 import org.teavm.backend.wasm.model.WasmFunction;
@@ -105,7 +106,6 @@ import org.teavm.model.instructions.CloneArrayInstruction;
 import org.teavm.model.instructions.InitClassInstruction;
 import org.teavm.model.instructions.InvocationType;
 import org.teavm.model.instructions.InvokeInstruction;
-import org.teavm.model.instructions.MutatorIntrinsic;
 import org.teavm.model.lowlevel.ClassInitializerEliminator;
 import org.teavm.model.lowlevel.ClassInitializerTransformer;
 import org.teavm.model.lowlevel.ShadowStackTransformer;
@@ -206,9 +206,9 @@ public class WasmTarget implements TeaVMTarget {
                 Address.class, int.class, void.class), null).use();
         dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "allocStack",
                 int.class, Address.class), null).use();
-        dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "getStackGcRoots", Address.class),
+        dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "getStackTop", Address.class),
                 null) .use();
-        dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "getNextStackRoots", Address.class,
+        dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "getNextStackFrame", Address.class,
                 Address.class), null).use();
         dependencyChecker.linkMethod(new MethodReference(WasmRuntime.class, "getStackRootCount", Address.class,
                 int.class), null).use();
@@ -294,7 +294,7 @@ public class WasmTarget implements TeaVMTarget {
         context.addIntrinsic(gcIntrinsic);
         MutatorIntrinsic mutatorIntrinsic = new MutatorIntrinsic();
         context.addIntrinsic(mutatorIntrinsic);
-        context.addIntrinsic(new ExceptionHandlingIntrinsic());
+        context.addIntrinsic(new ShadowStackIntrinsic());
 
         WasmGenerator generator = new WasmGenerator(decompiler, classes,
                 context, classGenerator);

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

@@ -113,10 +113,9 @@ import org.teavm.model.ValueType;
 import org.teavm.model.classes.TagRegistry;
 import org.teavm.model.classes.VirtualTableEntry;
 import org.teavm.runtime.Allocator;
-import org.teavm.runtime.ExceptionHandling;
-import org.teavm.runtime.Mutator;
 import org.teavm.runtime.RuntimeArray;
 import org.teavm.runtime.RuntimeClass;
+import org.teavm.runtime.ShadowStack;
 
 class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
     private static FieldReference tagField = new FieldReference(RuntimeClass.class.getName(), "tag");
@@ -783,7 +782,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     @Override
     public void visit(InvocationExpr expr) {
-        if (expr.getMethod().getClassName().equals(Mutator.class.getName())) {
+        if (expr.getMethod().getClassName().equals(ShadowStack.class.getName())) {
             switch (expr.getMethod().getName()) {
                 case "allocStack":
                     generateAllocStack(expr.getArguments().get(0));
@@ -791,19 +790,16 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
                 case "releaseStack":
                     generateReleaseStack();
                     return;
-                case "registerGcRoot":
+                case "registerGCRoot":
                     generateRegisterGcRoot(expr.getArguments().get(0), expr.getArguments().get(1));
                     return;
-                case "removeGcRoot":
+                case "removeGCRoot":
                     generateRemoveGcRoot(expr.getArguments().get(0));
                     return;
-            }
-        } else if (expr.getMethod().getClassName().equals(ExceptionHandling.class.getName())) {
-            switch (expr.getMethod().getName()) {
                 case "registerCallSite":
                     generateRegisterCallSite(expr.getArguments().get(0));
                     return;
-                case "getHandlerId":
+                case "getExceptionHandlerId":
                     generateGetHandlerId();
                     return;
             }
@@ -896,7 +892,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateAllocStack(Expr sizeExpr) {
         if (stackVariable != null) {
-            throw new IllegalStateException("Call to Mutator.allocStack must be done only once");
+            throw new IllegalStateException("Call to ShadowStack.allocStack must be done only once");
         }
         stackVariable = getTemporary(WasmType.INT32);
         stackVariable.setName("__stack__");
@@ -911,7 +907,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateReleaseStack() {
         if (stackVariable == null) {
-            throw new IllegalStateException("Call to Mutator.releaseStack must be dominated by "
+            throw new IllegalStateException("Call to ShadowStack.releaseStack must be dominated by "
                     + "Mutator.allocStack");
         }
 
@@ -924,7 +920,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateRegisterCallSite(Expr callSiteExpr) {
         if (stackVariable == null) {
-            throw new IllegalStateException("Call to ExceptionHandling.registerCallSite must be dominated by "
+            throw new IllegalStateException("Call to ShadowStack.registerCallSite must be dominated by "
                     + "Mutator.allocStack");
         }
 
@@ -936,7 +932,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateGetHandlerId() {
         if (stackVariable == null) {
-            throw new IllegalStateException("Call to ExceptionHandling.getHandlerId must be dominated by "
+            throw new IllegalStateException("Call to ShadowStack.getHandlerId must be dominated by "
                     + "Mutator.allocStack");
         }
 
@@ -945,7 +941,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateRegisterGcRoot(Expr slotExpr, Expr gcRootExpr) {
         if (stackVariable == null) {
-            throw new IllegalStateException("Call to Mutator.registerGcRoot must be dominated by "
+            throw new IllegalStateException("Call to ShadowStack.registerGCRoot must be dominated by "
                     + "Mutator.allocStack");
         }
 
@@ -962,7 +958,7 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
 
     private void generateRemoveGcRoot(Expr slotExpr) {
         if (stackVariable == null) {
-            throw new IllegalStateException("Call to Mutator.removeGcRoot must be dominated by "
+            throw new IllegalStateException("Call to ShadowStack.removeGCRoot must be dominated by "
                     + "Mutator.allocStack");
         }
 

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

@@ -13,15 +13,11 @@
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
  */
-package org.teavm.model.instructions;
+package org.teavm.backend.wasm.intrinsics;
 
 import java.util.ArrayList;
 import java.util.List;
-import org.teavm.ast.*;
+import org.teavm.ast.InvocationExpr;
-import org.teavm.ast.InvocationType;
-import org.teavm.backend.wasm.WasmRuntime;
-import org.teavm.backend.wasm.intrinsics.WasmIntrinsic;
-import org.teavm.backend.wasm.intrinsics.WasmIntrinsicManager;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.backend.wasm.model.expression.WasmInt32Constant;
 import org.teavm.model.MethodReference;
@@ -30,46 +26,34 @@ import org.teavm.runtime.Mutator;
 public class MutatorIntrinsic implements WasmIntrinsic {
     private List<WasmInt32Constant> staticGcRootsExpressions = new ArrayList<>();
 
-    @Override
-    public boolean isApplicable(MethodReference methodReference) {
-        if (!methodReference.getClassName().equals(Mutator.class.getName())) {
-            return false;
-        }
-        switch (methodReference.getName()) {
-            case "getStaticGcRoots":
-            case "getStackGcRoots":
-            case "getNextStackRoots":
-            case "getStackRootCount":
-            case "getStackRootPointer":
-                return true;
-            default:
-                return false;
-        }
-    }
-
     public void setStaticGcRootsAddress(int address) {
         for (WasmInt32Constant constant : staticGcRootsExpressions) {
             constant.setValue(address);
         }
     }
 
+    @Override
+    public boolean isApplicable(MethodReference methodReference) {
+        if (!methodReference.getClassName().equals(Mutator.class.getName())) {
+            return false;
+        }
+        switch (methodReference.getName()) {
+            case "getStaticGCRoots":
+                return true;
+            default:
+                return false;
+        }
+    }
+
     @Override
     public WasmExpression apply(InvocationExpr invocation, WasmIntrinsicManager manager) {
         switch (invocation.getMethod().getName()) {
-            case "getStaticGcRoots": {
+            case "getStaticGCRoots": {
                 WasmInt32Constant constant = new WasmInt32Constant(0);
                 staticGcRootsExpressions.add(constant);
                 return constant;
             }
-            default: {
-                InvocationExpr expr = new InvocationExpr();
-                MethodReference method = new MethodReference(WasmRuntime.class.getName(),
-                        invocation.getMethod().getDescriptor());
-                expr.setMethod(method);
-                expr.setType(InvocationType.SPECIAL);
-                expr.getArguments().addAll(invocation.getArguments());
-                return manager.generate(expr);
-            }
         }
+        throw new IllegalArgumentException(invocation.getMethod().toString());
     }
 }

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

@@ -16,33 +16,37 @@
 package org.teavm.backend.wasm.intrinsics;
 
 import org.teavm.ast.InvocationExpr;
+import org.teavm.ast.InvocationType;
+import org.teavm.backend.wasm.WasmRuntime;
 import org.teavm.backend.wasm.model.expression.WasmExpression;
 import org.teavm.model.MethodReference;
-import org.teavm.runtime.ExceptionHandling;
+import org.teavm.runtime.ShadowStack;
 
-public class ExceptionHandlingIntrinsic implements WasmIntrinsic {
+public class ShadowStackIntrinsic implements WasmIntrinsic {
     @Override
     public boolean isApplicable(MethodReference methodReference) {
-        if (!methodReference.getClassName().equals(ExceptionHandling.class.getName())) {
+        if (!methodReference.getClassName().equals(ShadowStack.class.getName())) {
             return false;
         }
-
         switch (methodReference.getName()) {
-            case "registerCallSite":
+            case "getStackTop":
-            case "getHandlerId":
+            case "getNextStackFrame":
+            case "getStackRootCount":
+            case "getStackRootPointer":
                 return true;
-        }
+            default:
-
                 return false;
         }
+    }
 
     @Override
     public WasmExpression apply(InvocationExpr invocation, WasmIntrinsicManager manager) {
-        switch (invocation.getMethod().getName()) {
+        InvocationExpr expr = new InvocationExpr();
-            case "registerCallSite":
+        MethodReference method = new MethodReference(WasmRuntime.class.getName(),
-                break;
+                invocation.getMethod().getDescriptor());
-        }
+        expr.setMethod(method);
-
+        expr.setType(InvocationType.SPECIAL);
-        throw new IllegalArgumentException(invocation.getMethod().toString());
+        expr.getArguments().addAll(invocation.getArguments());
+        return manager.generate(expr);
     }
 }

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

@@ -50,6 +50,7 @@ import org.teavm.model.instructions.SwitchTableEntry;
 import org.teavm.model.util.DefinitionExtractor;
 import org.teavm.model.util.ProgramUtils;
 import org.teavm.runtime.ExceptionHandling;
+import org.teavm.runtime.ShadowStack;
 
 public class ExceptionHandlingShadowStackContributor {
     private ManagedMethodRepository managedMethodRepository;
@@ -194,8 +195,7 @@ public class ExceptionHandlingShadowStackContributor {
         instructions.add(idInsn);
 
         InvokeInstruction registerInsn = new InvokeInstruction();
-        registerInsn.setMethod(new MethodReference(ExceptionHandling.class, "registerCallSite",
+        registerInsn.setMethod(new MethodReference(ShadowStack.class, "registerCallSite", int.class, void.class));
-                int.class, void.class));
         registerInsn.setType(InvocationType.SPECIAL);
         registerInsn.getArguments().add(idVariable);
         instructions.add(registerInsn);
@@ -219,7 +219,7 @@ public class ExceptionHandlingShadowStackContributor {
 
         Variable handlerIdVariable = program.createVariable();
         InvokeInstruction getHandlerIdInsn = new InvokeInstruction();
-        getHandlerIdInsn.setMethod(new MethodReference(ExceptionHandling.class, "getHandlerId", int.class));
+        getHandlerIdInsn.setMethod(new MethodReference(ShadowStack.class, "getExceptionHandlerId", int.class));
         getHandlerIdInsn.setType(InvocationType.SPECIAL);
         getHandlerIdInsn.setReceiver(handlerIdVariable);
         instructions.add(getHandlerIdInsn);

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

@@ -53,7 +53,7 @@ import org.teavm.model.util.ProgramUtils;
 import org.teavm.model.util.TypeInferer;
 import org.teavm.model.util.UsageExtractor;
 import org.teavm.model.util.VariableType;
-import org.teavm.runtime.Mutator;
+import org.teavm.runtime.ShadowStack;
 
 public class GCShadowStackContributor {
     private ManagedMethodRepository managedMethodRepository;
@@ -92,9 +92,9 @@ public class GCShadowStackContributor {
             findAutoSpilledPhis(spilled, destinationPhis, inputCount, autoSpilled, i);
         }
 
-        List<IntObjectMap<int[]>> liveInStores = reduceGcRootStores(program, usedColors, liveInInformation,
+        List<IntObjectMap<int[]>> liveInStores = reduceGCRootStores(program, usedColors, liveInInformation,
                 colors, autoSpilled);
-        putLiveInGcRoots(program, liveInStores);
+        putLiveInGCRoots(program, liveInStores);
 
         return usedColors;
     }
@@ -241,7 +241,7 @@ public class GCShadowStackContributor {
         return inputCount;
     }
 
-    private List<IntObjectMap<int[]>> reduceGcRootStores(Program program, int usedColors,
+    private List<IntObjectMap<int[]>> reduceGCRootStores(Program program, int usedColors,
             List<IntObjectMap<BitSet>> liveInInformation, int[] colors, boolean[] autoSpilled) {
         class Step {
             private final int node;
@@ -322,7 +322,7 @@ public class GCShadowStackContributor {
         return comparison;
     }
 
-    private void putLiveInGcRoots(Program program, List<IntObjectMap<int[]>> updateInformation) {
+    private void putLiveInGCRoots(Program program, List<IntObjectMap<int[]>> updateInformation) {
         for (int i = 0; i < program.basicBlockCount(); ++i) {
             BasicBlock block = program.basicBlockAt(i);
             IntObjectMap<int[]> updatesByIndex = updateInformation.get(i);
@@ -359,11 +359,11 @@ public class GCShadowStackContributor {
             registerInvocation.setType(InvocationType.SPECIAL);
             registerInvocation.getArguments().add(slotVar);
             if (var >= 0) {
-                registerInvocation.setMethod(new MethodReference(Mutator.class, "registerGcRoot", int.class,
+                registerInvocation.setMethod(new MethodReference(ShadowStack.class, "registerGCRoot", int.class,
                         Object.class, void.class));
                 registerInvocation.getArguments().add(program.variableAt(var));
             } else {
-                registerInvocation.setMethod(new MethodReference(Mutator.class, "removeGcRoot", int.class,
+                registerInvocation.setMethod(new MethodReference(ShadowStack.class, "removeGCRoot", int.class,
                         void.class));
             }
             instructionsToAdd.add(registerInvocation);

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

@@ -31,7 +31,7 @@ import org.teavm.model.instructions.IntegerConstantInstruction;
 import org.teavm.model.instructions.InvocationType;
 import org.teavm.model.instructions.InvokeInstruction;
 import org.teavm.model.instructions.JumpInstruction;
-import org.teavm.runtime.Mutator;
+import org.teavm.runtime.ShadowStack;
 
 public class ShadowStackTransformer {
     private ManagedMethodRepository managedMethodRepository;
@@ -70,7 +70,7 @@ public class ShadowStackTransformer {
 
         InvokeInstruction invocation = new InvokeInstruction();
         invocation.setType(InvocationType.SPECIAL);
-        invocation.setMethod(new MethodReference(Mutator.class, "allocStack", int.class, void.class));
+        invocation.setMethod(new MethodReference(ShadowStack.class, "allocStack", int.class, void.class));
         invocation.getArguments().add(sizeVariable);
         instructionsToAdd.add(invocation);
 
@@ -135,7 +135,7 @@ public class ShadowStackTransformer {
 
         InvokeInstruction invocation = new InvokeInstruction();
         invocation.setType(InvocationType.SPECIAL);
-        invocation.setMethod(new MethodReference(Mutator.class, "releaseStack", int.class, void.class));
+        invocation.setMethod(new MethodReference(ShadowStack.class, "releaseStack", int.class, void.class));
         invocation.getArguments().add(sizeVariable);
         instructionsToAdd.add(invocation);
 

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

@@ -26,20 +26,6 @@ public final class ExceptionHandling {
     private ExceptionHandling() {
     }
 
-    public static native void registerCallSite(int id);
-
-    public static native int callSiteResult();
-
-    public static native Address getStackTop();
-
-    public static native Address getNextStackFrame(Address stackFrame);
-
-    public static native int getCallSiteId(Address stackFrame);
-
-    public static native void setHandlerId(Address stackFrame, int id);
-
-    public static native int getHandlerId();
-
     public static native CallSite findCallSiteById(int id);
 
     public static void throwException(Throwable exception) {
@@ -47,23 +33,23 @@ public final class ExceptionHandling {
         RuntimeClass exceptionClass = RuntimeClass.getClass(exceptionPtr);
         IsSupertypeFunction isExceptionSupertype = exceptionClass.isSupertypeOf;
 
-        Address stackFrame = getStackTop();
+        Address stackFrame = ShadowStack.getStackTop();
         stackLoop: while (stackFrame != null) {
-            int callSiteId = getCallSiteId(stackFrame);
+            int callSiteId = ShadowStack.getCallSiteId(stackFrame);
             CallSite callSite = findCallSiteById(callSiteId);
             ExceptionHandler handler = callSite.firstHandler;
 
             for (int i = 0; i < callSite.handlerCount; ++i) {
                 if (isExceptionSupertype.apply(handler.exceptionClass)) {
-                    setHandlerId(stackFrame, handler.id);
+                    ShadowStack.setExceptionHandlerId(stackFrame, handler.id);
                     break stackLoop;
                 }
 
                 handler = Structure.add(ExceptionHandler.class, handler, 1);
             }
 
-            setHandlerId(stackFrame, callSiteId - 1);
+            ShadowStack.setExceptionHandlerId(stackFrame, callSiteId - 1);
-            stackFrame = getNextStackFrame(stackFrame);
+            stackFrame = ShadowStack.getNextStackFrame(stackFrame);
         }
     }
 }

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

@@ -109,7 +109,7 @@ public final class GC {
     private static void mark() {
         Allocator.fillZero(regionsAddress().toAddress(), regionMaxCount() * Structure.sizeOf(Region.class));
 
-        Address staticRoots = Mutator.getStaticGcRoots();
+        Address staticRoots = Mutator.getStaticGCRoots();
         int staticCount = staticRoots.getInt();
         staticRoots.add(8);
         while (staticCount-- > 0) {
@@ -120,10 +120,10 @@ public final class GC {
             staticRoots = staticRoots.add(Address.sizeOf());
         }
 
-        for (Address stackRoots = Mutator.getStackGcRoots(); stackRoots != null;
+        for (Address stackRoots = ShadowStack.getStackTop(); stackRoots != null;
-                stackRoots = Mutator.getNextStackRoots(stackRoots)) {
+             stackRoots = ShadowStack.getNextStackFrame(stackRoots)) {
-            int count = Mutator.getStackRootCount(stackRoots);
+            int count = ShadowStack.getStackRootCount(stackRoots);
-            Address stackRootsPtr = Mutator.getStackRootPointer(stackRoots);
+            Address stackRootsPtr = ShadowStack.getStackRootPointer(stackRoots);
             while (count-- > 0) {
                 RuntimeObject obj = stackRootsPtr.getAddress().toStructure();
                 mark(obj);

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

@@ -25,21 +25,5 @@ public final class Mutator {
     private Mutator() {
     }
 
-    public static native void allocStack(int size);
+    public static native Address getStaticGCRoots();
-
-    public static native void registerGcRoot(int index, Object object);
-
-    public static native void removeGcRoot(int index);
-
-    public static native void releaseStack(int size);
-
-    public static native Address getStaticGcRoots();
-
-    public static native Address getStackGcRoots();
-
-    public static native Address getNextStackRoots(Address address);
-
-    public static native int getStackRootCount(Address address);
-
-    public static native Address getStackRootPointer(Address address);
 }

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

@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2016 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.Address;
+import org.teavm.interop.StaticInit;
+import org.teavm.interop.Unmanaged;
+
+@Unmanaged
+@StaticInit
+public final class ShadowStack {
+    private ShadowStack() {
+    }
+
+    public static native void allocStack(int size);
+
+    public static native void registerGCRoot(int index, Object object);
+
+    public static native void removeGCRoot(int index);
+
+    public static native void releaseStack(int size);
+
+    public static native Address getStackTop();
+
+    public static native Address getNextStackFrame(Address stackFrame);
+
+    public static native int getStackRootCount(Address stackFrame);
+
+    public static native Address getStackRootPointer(Address stackFrame);
+
+    public static native int getCallSiteId(Address stackFrame);
+
+    public static native void registerCallSite(int id);
+
+    public static native int getExceptionHandlerId();
+
+    public static native void setExceptionHandlerId(Address stackFrame, int id);
+}