src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/stubs/ExceptionHandlerStub.java
changeset 47216 71c04702a3d5
parent 46762 f7defa99f173
child 49873 26ebfe8ce852
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.internal.vm.compiler/share/classes/org.graalvm.compiler.hotspot/src/org/graalvm/compiler/hotspot/stubs/ExceptionHandlerStub.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,163 @@
+/*
+ * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package org.graalvm.compiler.hotspot.stubs;
+
+import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfig.INJECTED_VMCONFIG;
+import static org.graalvm.compiler.hotspot.nodes.JumpToExceptionHandlerNode.jumpToExceptionHandler;
+import static org.graalvm.compiler.hotspot.nodes.PatchReturnAddressNode.patchReturnAddress;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.readExceptionOop;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.readExceptionPc;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.registerAsWord;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.writeExceptionOop;
+import static org.graalvm.compiler.hotspot.replacements.HotSpotReplacementsUtil.writeExceptionPc;
+import static org.graalvm.compiler.hotspot.stubs.StubUtil.cAssertionsEnabled;
+import static org.graalvm.compiler.hotspot.stubs.StubUtil.decipher;
+import static org.graalvm.compiler.hotspot.stubs.StubUtil.fatal;
+import static org.graalvm.compiler.hotspot.stubs.StubUtil.newDescriptor;
+import static org.graalvm.compiler.hotspot.stubs.StubUtil.printf;
+
+import org.graalvm.compiler.api.replacements.Fold;
+import org.graalvm.compiler.api.replacements.Fold.InjectedParameter;
+import org.graalvm.compiler.api.replacements.Snippet;
+import org.graalvm.compiler.api.replacements.Snippet.ConstantParameter;
+import org.graalvm.compiler.core.common.spi.ForeignCallDescriptor;
+import org.graalvm.compiler.debug.Assertions;
+import org.graalvm.compiler.graph.Node.ConstantNodeParameter;
+import org.graalvm.compiler.graph.Node.NodeIntrinsic;
+import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;
+import org.graalvm.compiler.hotspot.HotSpotBackend;
+import org.graalvm.compiler.hotspot.HotSpotForeignCallLinkage;
+import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
+import org.graalvm.compiler.hotspot.nodes.StubForeignCallNode;
+import org.graalvm.compiler.options.OptionValues;
+import org.graalvm.compiler.word.Word;
+import org.graalvm.word.WordFactory;
+
+import jdk.vm.ci.code.Register;
+
+/**
+ * Stub called by the {@linkplain GraalHotSpotVMConfig#MARKID_EXCEPTION_HANDLER_ENTRY exception
+ * handler entry point} in a compiled method. This entry point is used when returning to a method to
+ * handle an exception thrown by a callee. It is not used for routing implicit exceptions.
+ * Therefore, it does not need to save any registers as HotSpot uses a caller save convention.
+ * <p>
+ * The descriptor for a call to this stub is {@link HotSpotBackend#EXCEPTION_HANDLER}.
+ */
+public class ExceptionHandlerStub extends SnippetStub {
+
+    public ExceptionHandlerStub(OptionValues options, HotSpotProviders providers, HotSpotForeignCallLinkage linkage) {
+        super("exceptionHandler", options, providers, linkage);
+    }
+
+    /**
+     * This stub is called when returning to a method to handle an exception thrown by a callee. It
+     * is not used for routing implicit exceptions. Therefore, it does not need to save any
+     * registers as HotSpot uses a caller save convention.
+     */
+    @Override
+    public boolean preservesRegisters() {
+        return false;
+    }
+
+    @Override
+    protected Object getConstantParameterValue(int index, String name) {
+        if (index == 2) {
+            return providers.getRegisters().getThreadRegister();
+        }
+        assert index == 3;
+        return options;
+    }
+
+    @Snippet
+    private static void exceptionHandler(Object exception, Word exceptionPc, @ConstantParameter Register threadRegister, @ConstantParameter OptionValues options) {
+        Word thread = registerAsWord(threadRegister);
+        checkNoExceptionInThread(thread, assertionsEnabled(INJECTED_VMCONFIG));
+        checkExceptionNotNull(assertionsEnabled(INJECTED_VMCONFIG), exception);
+        writeExceptionOop(thread, exception);
+        writeExceptionPc(thread, exceptionPc);
+        if (logging(options)) {
+            printf("handling exception %p (", Word.objectToTrackedPointer(exception).rawValue());
+            decipher(Word.objectToTrackedPointer(exception).rawValue());
+            printf(") at %p (", exceptionPc.rawValue());
+            decipher(exceptionPc.rawValue());
+            printf(")\n");
+        }
+
+        // patch throwing pc into return address so that deoptimization finds the right debug info
+        patchReturnAddress(exceptionPc);
+
+        Word handlerPc = exceptionHandlerForPc(EXCEPTION_HANDLER_FOR_PC, thread);
+
+        if (logging(options)) {
+            printf("handler for exception %p at %p is at %p (", Word.objectToTrackedPointer(exception).rawValue(), exceptionPc.rawValue(), handlerPc.rawValue());
+            decipher(handlerPc.rawValue());
+            printf(")\n");
+        }
+
+        // patch the return address so that this stub returns to the exception handler
+        jumpToExceptionHandler(handlerPc);
+    }
+
+    static void checkNoExceptionInThread(Word thread, boolean enabled) {
+        if (enabled) {
+            Object currentException = readExceptionOop(thread);
+            if (currentException != null) {
+                fatal("exception object in thread must be null, not %p", Word.objectToTrackedPointer(currentException).rawValue());
+            }
+            if (cAssertionsEnabled(INJECTED_VMCONFIG)) {
+                // This thread-local is only cleared in DEBUG builds of the VM
+                // (see OptoRuntime::generate_exception_blob)
+                Word currentExceptionPc = readExceptionPc(thread);
+                if (currentExceptionPc.notEqual(WordFactory.zero())) {
+                    fatal("exception PC in thread must be zero, not %p", currentExceptionPc.rawValue());
+                }
+            }
+        }
+    }
+
+    static void checkExceptionNotNull(boolean enabled, Object exception) {
+        if (enabled && exception == null) {
+            fatal("exception must not be null");
+        }
+    }
+
+    @Fold
+    static boolean logging(OptionValues options) {
+        return StubOptions.TraceExceptionHandlerStub.getValue(options);
+    }
+
+    /**
+     * Determines if either Java assertions are enabled for Graal or if this is a HotSpot build
+     * where the ASSERT mechanism is enabled.
+     */
+    @Fold
+    @SuppressWarnings("all")
+    static boolean assertionsEnabled(@InjectedParameter GraalHotSpotVMConfig config) {
+        return Assertions.assertionsEnabled() || cAssertionsEnabled(config);
+    }
+
+    public static final ForeignCallDescriptor EXCEPTION_HANDLER_FOR_PC = newDescriptor(ExceptionHandlerStub.class, "exceptionHandlerForPc", Word.class, Word.class);
+
+    @NodeIntrinsic(value = StubForeignCallNode.class)
+    public static native Word exceptionHandlerForPc(@ConstantNodeParameter ForeignCallDescriptor exceptionHandlerForPc, Word thread);
+}