Source code

001/*
002 * Copyright (c) 2012, 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package com.oracle.graal.hotspot.stubs;
024
025import com.oracle.graal.debug.*;
026
027import jdk.internal.jvmci.hotspot.*;
028import jdk.internal.jvmci.meta.*;
029import static com.oracle.graal.hotspot.HotSpotForeignCallLinkage.RegisterEffect.*;
030import static jdk.internal.jvmci.code.CallingConvention.Type.*;
031
032import com.oracle.graal.compiler.common.spi.*;
033import com.oracle.graal.compiler.common.type.*;
034import com.oracle.graal.hotspot.*;
035import com.oracle.graal.hotspot.HotSpotForeignCallLinkage.Transition;
036import com.oracle.graal.hotspot.meta.*;
037import com.oracle.graal.hotspot.nodes.*;
038import com.oracle.graal.hotspot.replacements.*;
039import com.oracle.graal.nodes.*;
040import com.oracle.graal.nodes.StructuredGraph.AllowAssumptions;
041import com.oracle.graal.replacements.*;
042import com.oracle.graal.replacements.nodes.*;
043import com.oracle.graal.word.*;
044
045/**
046 * A {@linkplain #getGraph() generated} stub for a {@link Transition non-leaf} foreign call from
047 * compiled code. A stub is required for such calls as the caller may be scheduled for
048 * deoptimization while the call is in progress. And since these are foreign/runtime calls on slow
049 * paths, we don't want to force the register allocator to spill around the call. As such, this stub
050 * saves and restores all allocatable registers. It also
051 * {@linkplain StubUtil#handlePendingException(Word, boolean) handles} any exceptions raised during
052 * the foreign call.
053 */
054public class ForeignCallStub extends Stub {
055
056    private final HotSpotGraalRuntimeProvider runtime;
057
058    /**
059     * The target of the call.
060     */
061    private final HotSpotForeignCallLinkage target;
062
063    /**
064     * Specifies if the JavaThread value for the current thread is to be prepended to the arguments
065     * for the call to {@link #target}.
066     */
067    protected final boolean prependThread;
068
069    /**
070     * Creates a stub for a call to code at a given address.
071     *
072     * @param address the address of the code to call
073     * @param descriptor the signature of the call to this stub
074     * @param prependThread true if the JavaThread value for the current thread is to be prepended
075     *            to the arguments for the call to {@code address}
076     * @param reexecutable specifies if the stub call can be re-executed without (meaningful) side
077     *            effects. Deoptimization will not return to a point before a stub call that cannot
078     *            be re-executed.
079     * @param killedLocations the memory locations killed by the stub call
080     */
081    public ForeignCallStub(HotSpotGraalRuntimeProvider runtime, HotSpotProviders providers, long address, ForeignCallDescriptor descriptor, boolean prependThread, Transition transition,
082                    boolean reexecutable, LocationIdentity... killedLocations) {
083        super(providers, HotSpotForeignCallLinkageImpl.create(providers.getMetaAccess(), providers.getCodeCache(), providers.getForeignCalls(), descriptor, 0L, PRESERVES_REGISTERS, JavaCall,
084                        JavaCallee, transition, reexecutable, killedLocations));
085        this.runtime = runtime;
086        this.prependThread = prependThread;
087        Class<?>[] targetParameterTypes = createTargetParameters(descriptor);
088        ForeignCallDescriptor targetSig = new ForeignCallDescriptor(descriptor.getName() + ":C", descriptor.getResultType(), targetParameterTypes);
089        target = HotSpotForeignCallLinkageImpl.create(providers.getMetaAccess(), providers.getCodeCache(), providers.getForeignCalls(), targetSig, address, DESTROYS_REGISTERS, NativeCall, NativeCall,
090                        transition, reexecutable, killedLocations);
091    }
092
093    /**
094     * Gets the linkage information for the call from this stub.
095     */
096    public HotSpotForeignCallLinkage getTargetLinkage() {
097        return target;
098    }
099
100    private Class<?>[] createTargetParameters(ForeignCallDescriptor descriptor) {
101        Class<?>[] parameters = descriptor.getArgumentTypes();
102        if (prependThread) {
103            Class<?>[] newParameters = new Class[parameters.length + 1];
104            System.arraycopy(parameters, 0, newParameters, 1, parameters.length);
105            newParameters[0] = Word.class;
106            return newParameters;
107        }
108        return parameters;
109    }
110
111    @Override
112    protected ResolvedJavaMethod getInstalledCodeOwner() {
113        return null;
114    }
115
116    private class DebugScopeContext implements JavaMethod, JavaMethodContext {
117        public JavaMethod asJavaMethod() {
118            return this;
119        }
120
121        public Signature getSignature() {
122            ForeignCallDescriptor d = linkage.getDescriptor();
123            MetaAccessProvider metaAccess = providers.getMetaAccess();
124            Class<?>[] arguments = d.getArgumentTypes();
125            ResolvedJavaType[] parameters = new ResolvedJavaType[arguments.length];
126            for (int i = 0; i < arguments.length; i++) {
127                parameters[i] = metaAccess.lookupJavaType(arguments[i]);
128            }
129            return new HotSpotSignature(runtime.getJVMCIRuntime(), metaAccess.lookupJavaType(d.getResultType()), parameters);
130        }
131
132        public String getName() {
133            return linkage.getDescriptor().getName();
134        }
135
136        public JavaType getDeclaringClass() {
137            return providers.getMetaAccess().lookupJavaType(ForeignCallStub.class);
138        }
139
140        @Override
141        public String toString() {
142            return format("ForeignCallStub<%n(%p)>");
143        }
144    }
145
146    @Override
147    protected Object debugScopeContext() {
148        return new DebugScopeContext() {
149
150        };
151    }
152
153    /**
154     * Creates a graph for this stub.
155     * <p>
156     * If the stub returns an object, the graph created corresponds to this pseudo code:
157     *
158     * <pre>
159     *     Object foreignFunctionStub(args...) {
160     *         foreignFunction(currentThread,  args);
161     *         if (clearPendingException(thread())) {
162     *             getAndClearObjectResult(thread());
163     *             DeoptimizeCallerNode.deopt(InvalidateReprofile, RuntimeConstraint);
164     *         }
165     *         return verifyObject(getAndClearObjectResult(thread()));
166     *     }
167     * </pre>
168     *
169     * If the stub returns a primitive or word, the graph created corresponds to this pseudo code
170     * (using {@code int} as the primitive return type):
171     *
172     * <pre>
173     *     int foreignFunctionStub(args...) {
174     *         int result = foreignFunction(currentThread,  args);
175     *         if (clearPendingException(thread())) {
176     *             DeoptimizeCallerNode.deopt(InvalidateReprofile, RuntimeConstraint);
177     *         }
178     *         return result;
179     *     }
180     * </pre>
181     *
182     * If the stub is void, the graph created corresponds to this pseudo code:
183     *
184     * <pre>
185     *     void foreignFunctionStub(args...) {
186     *         foreignFunction(currentThread,  args);
187     *         if (clearPendingException(thread())) {
188     *             DeoptimizeCallerNode.deopt(InvalidateReprofile, RuntimeConstraint);
189     *         }
190     *     }
191     * </pre>
192     *
193     * In each example above, the {@code currentThread} argument is the C++ JavaThread value (i.e.,
194     * %r15 on AMD64) and is only prepended if {@link #prependThread} is true.
195     */
196    @Override
197    protected StructuredGraph getGraph() {
198        WordTypes wordTypes = providers.getWordTypes();
199        Class<?>[] args = linkage.getDescriptor().getArgumentTypes();
200        boolean isObjectResult = linkage.getOutgoingCallingConvention().getReturn().getKind() == Kind.Object;
201
202        StructuredGraph graph = new StructuredGraph(toString(), null, AllowAssumptions.NO);
203        graph.disableInlinedMethodRecording();
204        graph.disableUnsafeAccessTracking();
205
206        GraphKit kit = new GraphKit(graph, providers, wordTypes, providers.getGraphBuilderPlugins());
207        ParameterNode[] params = createParameters(kit, args);
208
209        ReadRegisterNode thread = kit.append(new ReadRegisterNode(providers.getRegisters().getThreadRegister(), wordTypes.getWordKind(), true, false));
210        ValueNode result = createTargetCall(kit, params, thread);
211        kit.createInvoke(StubUtil.class, "handlePendingException", thread, ConstantNode.forBoolean(isObjectResult, graph));
212        if (isObjectResult) {
213            InvokeNode object = kit.createInvoke(HotSpotReplacementsUtil.class, "getAndClearObjectResult", thread);
214            result = kit.createInvoke(StubUtil.class, "verifyObject", object);
215        }
216        kit.append(new ReturnNode(linkage.getDescriptor().getResultType() == void.class ? null : result));
217
218        if (Debug.isDumpEnabled()) {
219            Debug.dump(graph, "Initial stub graph");
220        }
221
222        kit.inlineInvokes();
223
224        if (Debug.isDumpEnabled()) {
225            Debug.dump(graph, "Stub graph before compilation");
226        }
227
228        return graph;
229    }
230
231    private ParameterNode[] createParameters(GraphKit kit, Class<?>[] args) {
232        ParameterNode[] params = new ParameterNode[args.length];
233        ResolvedJavaType accessingClass = providers.getMetaAccess().lookupJavaType(getClass());
234        for (int i = 0; i < args.length; i++) {
235            ResolvedJavaType type = providers.getMetaAccess().lookupJavaType(args[i]).resolve(accessingClass);
236            Stamp stamp;
237            if (type.getKind().getStackKind() == Kind.Object) {
238                stamp = StampFactory.declared(type);
239            } else {
240                stamp = StampFactory.forKind(type.getKind());
241            }
242            ParameterNode param = kit.unique(new ParameterNode(i, stamp));
243            params[i] = param;
244        }
245        return params;
246    }
247
248    private StubForeignCallNode createTargetCall(GraphKit kit, ParameterNode[] params, ReadRegisterNode thread) {
249        if (prependThread) {
250            ValueNode[] targetArguments = new ValueNode[1 + params.length];
251            targetArguments[0] = thread;
252            System.arraycopy(params, 0, targetArguments, 1, params.length);
253            return kit.append(new StubForeignCallNode(providers.getForeignCalls(), target.getDescriptor(), targetArguments));
254        } else {
255            return kit.append(new StubForeignCallNode(providers.getForeignCalls(), target.getDescriptor(), params));
256        }
257    }
258}