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package org.graalvm.compiler.hotspot;

import static org.graalvm.compiler.core.common.GraalOptions.OptAssumptions;

import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.util.Collections;
import java.util.Formattable;
import java.util.Formatter;
import java.util.List;

import org.graalvm.compiler.api.runtime.GraalJVMCICompiler;
import org.graalvm.compiler.code.CompilationResult;
import org.graalvm.compiler.core.GraalCompiler;
import org.graalvm.compiler.core.common.CompilationIdentifier;
import org.graalvm.compiler.core.common.util.CompilationAlarm;
import org.graalvm.compiler.debug.DebugContext;
import org.graalvm.compiler.debug.DebugContext.Activation;
import org.graalvm.compiler.debug.DebugHandlersFactory;
import org.graalvm.compiler.debug.DebugOptions;
import org.graalvm.compiler.hotspot.CompilationCounters.Options;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.hotspot.phases.OnStackReplacementPhase;
import org.graalvm.compiler.java.GraphBuilderPhase;
import org.graalvm.compiler.lir.asm.CompilationResultBuilderFactory;
import org.graalvm.compiler.lir.phases.LIRSuites;
import org.graalvm.compiler.nodes.Cancellable;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;
import org.graalvm.compiler.nodes.graphbuilderconf.GraphBuilderConfiguration;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.phases.OptimisticOptimizations;
import org.graalvm.compiler.phases.OptimisticOptimizations.Optimization;
import org.graalvm.compiler.phases.PhaseSuite;
import org.graalvm.compiler.phases.tiers.HighTierContext;
import org.graalvm.compiler.phases.tiers.Suites;
import org.graalvm.compiler.printer.GraalDebugHandlersFactory;
import org.graalvm.compiler.serviceprovider.GraalUnsafeAccess;

import jdk.vm.ci.code.CompilationRequest;
import jdk.vm.ci.code.CompilationRequestResult;
import jdk.vm.ci.hotspot.HotSpotCompilationRequest;
import jdk.vm.ci.hotspot.HotSpotCompilationRequestResult;
import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
import jdk.vm.ci.meta.DefaultProfilingInfo;
import jdk.vm.ci.meta.JavaMethod;
import jdk.vm.ci.meta.ProfilingInfo;
import jdk.vm.ci.meta.ResolvedJavaMethod;
import jdk.vm.ci.meta.SpeculationLog;
import jdk.vm.ci.meta.TriState;
import jdk.vm.ci.runtime.JVMCICompiler;
import sun.misc.Unsafe;

public class HotSpotGraalCompiler implements GraalJVMCICompiler, Cancellable {

    private static final Unsafe UNSAFE = GraalUnsafeAccess.getUnsafe();
    private final HotSpotJVMCIRuntime jvmciRuntime;
    private final HotSpotGraalRuntimeProvider graalRuntime;
    private final CompilationCounters compilationCounters;
    private final BootstrapWatchDog bootstrapWatchDog;
    private List<DebugHandlersFactory> factories;

    HotSpotGraalCompiler(HotSpotJVMCIRuntime jvmciRuntime, HotSpotGraalRuntimeProvider graalRuntime, OptionValues options) {
        this.jvmciRuntime = jvmciRuntime;
        this.graalRuntime = graalRuntime;
        // It is sufficient to have one compilation counter object per compiler object.
        this.compilationCounters = Options.CompilationCountLimit.getValue(options) > 0 ? new CompilationCounters(options) : null;
        this.bootstrapWatchDog = graalRuntime.isBootstrapping() && !DebugOptions.BootstrapInitializeOnly.getValue(options) ? BootstrapWatchDog.maybeCreate(graalRuntime) : null;
    }

    public List<DebugHandlersFactory> getDebugHandlersFactories() {
        if (factories == null) {
            factories = Collections.singletonList(new GraalDebugHandlersFactory(graalRuntime.getHostProviders().getSnippetReflection()));
        }
        return factories;
    }

    @Override
    public HotSpotGraalRuntimeProvider getGraalRuntime() {
        return graalRuntime;
    }

    @Override
    public CompilationRequestResult compileMethod(CompilationRequest request) {
        return compileMethod(request, true, graalRuntime.getOptions());
    }

    @SuppressWarnings("try")
    CompilationRequestResult compileMethod(CompilationRequest request, boolean installAsDefault, OptionValues initialOptions) {
        try (CompilationContext scope = HotSpotGraalServices.openLocalCompilationContext(request)) {
            if (graalRuntime.isShutdown()) {
                return HotSpotCompilationRequestResult.failure(String.format("Shutdown entered"), true);
            }

            ResolvedJavaMethod method = request.getMethod();

            if (graalRuntime.isBootstrapping()) {
                if (DebugOptions.BootstrapInitializeOnly.getValue(initialOptions)) {
                    return HotSpotCompilationRequestResult.failure(String.format("Skip compilation because %s is enabled", DebugOptions.BootstrapInitializeOnly.getName()), true);
                }
                if (bootstrapWatchDog != null) {
                    if (bootstrapWatchDog.hitCriticalCompilationRateOrTimeout()) {
                        // Drain the compilation queue to expedite completion of the bootstrap
                        return HotSpotCompilationRequestResult.failure("hit critical bootstrap compilation rate or timeout", true);
                    }
                }
            }
            HotSpotCompilationRequest hsRequest = (HotSpotCompilationRequest) request;
            CompilationTask task = new CompilationTask(jvmciRuntime, this, hsRequest, true, shouldRetainLocalVariables(hsRequest.getJvmciEnv()), installAsDefault);
            OptionValues options = task.filterOptions(initialOptions);
            try (CompilationWatchDog w1 = CompilationWatchDog.watch(method, hsRequest.getId(), options);
                            BootstrapWatchDog.Watch w2 = bootstrapWatchDog == null ? null : bootstrapWatchDog.watch(request);
                            CompilationAlarm alarm = CompilationAlarm.trackCompilationPeriod(options);) {
                if (compilationCounters != null) {
                    compilationCounters.countCompilation(method);
                }
                CompilationRequestResult r = null;
                try (DebugContext debug = graalRuntime.openDebugContext(options, task.getCompilationIdentifier(), method, getDebugHandlersFactories(), DebugContext.DEFAULT_LOG_STREAM);
                                Activation a = debug.activate()) {
                    r = task.runCompilation(debug);
                }
                assert r != null;
                return r;
            }
        }
    }

    private boolean shouldRetainLocalVariables(long envAddress) {
        GraalHotSpotVMConfig config = graalRuntime.getVMConfig();
        if (envAddress == 0) {
            return false;
        }
        if (config.jvmciCompileStateCanPopFrameOffset != Integer.MIN_VALUE) {
            if ((UNSAFE.getByte(envAddress + config.jvmciCompileStateCanPopFrameOffset) & 0xFF) != 0) {
                return true;
            }
        }
        if (config.jvmciCompileStateCanAccessLocalVariablesOffset != Integer.MIN_VALUE) {
            if ((UNSAFE.getByte(envAddress + config.jvmciCompileStateCanAccessLocalVariablesOffset) & 0xFF) != 0) {
                return true;
            }
        }
        return false;
    }

    @Override
    public boolean isCancelled() {
        return graalRuntime.isShutdown();
    }

    public StructuredGraph createGraph(ResolvedJavaMethod method, int entryBCI, boolean useProfilingInfo, CompilationIdentifier compilationId, OptionValues options, DebugContext debug) {
        HotSpotBackend backend = graalRuntime.getHostBackend();
        HotSpotProviders providers = backend.getProviders();
        final boolean isOSR = entryBCI != JVMCICompiler.INVOCATION_ENTRY_BCI;
        StructuredGraph graph = method.isNative() || isOSR ? null : providers.getReplacements().getIntrinsicGraph(method, compilationId, debug, this);

        if (graph == null) {
            SpeculationLog speculationLog = method.getSpeculationLog();
            if (speculationLog != null) {
                speculationLog.collectFailedSpeculations();
            }
            // @formatter:off
            graph = new StructuredGraph.Builder(options, debug, AllowAssumptions.ifTrue(OptAssumptions.getValue(options))).
                            method(method).
                            cancellable(this).
                            entryBCI(entryBCI).
                            speculationLog(speculationLog).
                            useProfilingInfo(useProfilingInfo).
                            compilationId(compilationId).build();
            // @formatter:on
        }
        return graph;
    }

    public CompilationResult compileHelper(CompilationResultBuilderFactory crbf, CompilationResult result, StructuredGraph graph, ResolvedJavaMethod method, int entryBCI, boolean useProfilingInfo,
                    OptionValues options) {
        return compileHelper(crbf, result, graph, method, entryBCI, useProfilingInfo, false, options);
    }

    public CompilationResult compileHelper(CompilationResultBuilderFactory crbf, CompilationResult result, StructuredGraph graph, ResolvedJavaMethod method, int entryBCI, boolean useProfilingInfo,
                    boolean shouldRetainLocalVariables, OptionValues options) {
        assert options == graph.getOptions();
        HotSpotBackend backend = graalRuntime.getHostBackend();
        HotSpotProviders providers = backend.getProviders();
        final boolean isOSR = entryBCI != JVMCICompiler.INVOCATION_ENTRY_BCI;

        Suites suites = getSuites(providers, options);
        LIRSuites lirSuites = getLIRSuites(providers, options);
        ProfilingInfo profilingInfo = useProfilingInfo ? method.getProfilingInfo(!isOSR, isOSR) : DefaultProfilingInfo.get(TriState.FALSE);
        OptimisticOptimizations optimisticOpts = getOptimisticOpts(profilingInfo, options);

        /*
         * Cut off never executed code profiles if there is code, e.g. after the osr loop, that is
         * never executed.
         */
        if (isOSR && !OnStackReplacementPhase.Options.DeoptAfterOSR.getValue(options)) {
            optimisticOpts.remove(Optimization.RemoveNeverExecutedCode);
        }

        result.setEntryBCI(entryBCI);
        boolean shouldDebugNonSafepoints = providers.getCodeCache().shouldDebugNonSafepoints();
        PhaseSuite<HighTierContext> graphBuilderSuite = configGraphBuilderSuite(providers.getSuites().getDefaultGraphBuilderSuite(), shouldDebugNonSafepoints, shouldRetainLocalVariables, isOSR);
        GraalCompiler.compileGraph(graph, method, providers, backend, graphBuilderSuite, optimisticOpts, profilingInfo, suites, lirSuites, result, crbf, true);

        if (!isOSR && useProfilingInfo) {
            ProfilingInfo profile = profilingInfo;
            profile.setCompilerIRSize(StructuredGraph.class, graph.getNodeCount());
        }

        return result;
    }

    public CompilationResult compile(ResolvedJavaMethod method,
                    int entryBCI,
                    boolean useProfilingInfo,
                    boolean shouldRetainLocalVariables,
                    CompilationIdentifier compilationId,
                    DebugContext debug) {
        StructuredGraph graph = createGraph(method, entryBCI, useProfilingInfo, compilationId, debug.getOptions(), debug);
        CompilationResult result = new CompilationResult(compilationId);
        return compileHelper(CompilationResultBuilderFactory.Default, result, graph, method, entryBCI, useProfilingInfo, shouldRetainLocalVariables, debug.getOptions());
    }

    protected OptimisticOptimizations getOptimisticOpts(ProfilingInfo profilingInfo, OptionValues options) {
        return new OptimisticOptimizations(profilingInfo, options);
    }

    protected Suites getSuites(HotSpotProviders providers, OptionValues options) {
        return providers.getSuites().getDefaultSuites(options);
    }

    protected LIRSuites getLIRSuites(HotSpotProviders providers, OptionValues options) {
        return providers.getSuites().getDefaultLIRSuites(options);
    }

    /**
     * Reconfigures a given graph builder suite (GBS) if one of the given GBS parameter values is
     * not the default.
     *
     * @param suite the graph builder suite
     * @param shouldDebugNonSafepoints specifies if extra debug info should be generated (default is
     *            false)
     * @param shouldRetainLocalVariables specifies if local variables should be retained for
     *            debugging purposes (default is false)
     * @param isOSR specifies if extra OSR-specific post-processing is required (default is false)
     * @return a new suite derived from {@code suite} if any of the GBS parameters did not have a
     *         default value otherwise {@code suite}
     */
    protected PhaseSuite<HighTierContext> configGraphBuilderSuite(PhaseSuite<HighTierContext> suite, boolean shouldDebugNonSafepoints, boolean shouldRetainLocalVariables, boolean isOSR) {
        if (shouldDebugNonSafepoints || shouldRetainLocalVariables || isOSR) {
            PhaseSuite<HighTierContext> newGbs = suite.copy();
            GraphBuilderPhase graphBuilderPhase = (GraphBuilderPhase) newGbs.findPhase(GraphBuilderPhase.class).previous();
            GraphBuilderConfiguration graphBuilderConfig = graphBuilderPhase.getGraphBuilderConfig();
            if (shouldDebugNonSafepoints) {
                graphBuilderConfig = graphBuilderConfig.withNodeSourcePosition(true);
            }
            if (shouldRetainLocalVariables) {
                graphBuilderConfig = graphBuilderConfig.withRetainLocalVariables(true);
            }
            GraphBuilderPhase newGraphBuilderPhase = new GraphBuilderPhase(graphBuilderConfig);
            newGbs.findPhase(GraphBuilderPhase.class).set(newGraphBuilderPhase);
            if (isOSR) {
                newGbs.appendPhase(new OnStackReplacementPhase());
            }
            return newGbs;
        }
        return suite;
    }

    /**
     * Converts {@code method} to a String with {@link JavaMethod#format(String)} and the format
     * string {@code "%H.%n(%p)"}.
     */
    static String str(JavaMethod method) {
        return method.format("%H.%n(%p)");
    }

    /**
     * Wraps {@code obj} in a {@link Formatter} that standardizes formatting for certain objects.
     */
    static Formattable fmt(Object obj) {
        return new Formattable() {
            @Override
            public void formatTo(Formatter buf, int flags, int width, int precision) {
                if (obj instanceof Throwable) {
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    ((Throwable) obj).printStackTrace(new PrintStream(baos));
                    buf.format("%s", baos.toString());
                } else if (obj instanceof StackTraceElement[]) {
                    for (StackTraceElement e : (StackTraceElement[]) obj) {
                        buf.format("\t%s%n", e);
                    }
                } else if (obj instanceof JavaMethod) {
                    buf.format("%s", str((JavaMethod) obj));
                } else {
                    buf.format("%s", obj);
                }
            }
        };
    }
}
