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   1 /*******************************************************************************
   2  * Copyright (c) 2015 EfficiOS Inc., Alexandre Montplaisir
   3  *
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *******************************************************************************/
   9
  10 package org.eclipse.tracecompass.lttng2.ust.core.analysis.debuginfo;
  11
  12 import static org.eclipse.tracecompass.common.core.NonNullUtils.nullToEmptyString;
  13
  14 import java.io.File;
  15
  16 import org.eclipse.jdt.annotation.Nullable;
  17 import org.eclipse.tracecompass.internal.lttng2.ust.core.analysis.debuginfo.FileOffsetMapper;
  18 import org.eclipse.tracecompass.internal.lttng2.ust.core.analysis.debuginfo.UstDebugInfoLoadedBinaryFile;
  19 import org.eclipse.tracecompass.lttng2.ust.core.trace.LttngUstTrace;
  20 import org.eclipse.tracecompass.lttng2.ust.core.trace.layout.ILttngUstEventLayout;
  21 import org.eclipse.tracecompass.tmf.core.event.ITmfEvent;
  22 import org.eclipse.tracecompass.tmf.core.event.ITmfEventField;
  23 import org.eclipse.tracecompass.tmf.core.event.aspect.ITmfEventAspect;
  24 import org.eclipse.tracecompass.tmf.core.event.lookup.TmfCallsite;
  25 import org.eclipse.tracecompass.tmf.core.trace.TmfTraceUtils;
  26
  27 import com.google.common.collect.Iterables;
  28
  29 /**
  30  * Event aspect of UST traces to generate a {@link TmfCallsite} using the debug
  31  * info analysis and the IP (instruction pointer) context.
  32  *
  33  * @author Alexandre Montplaisir
  34  * @since 2.0
  35  */
  36 public class UstDebugInfoSourceAspect implements ITmfEventAspect {
  37
  38     /** Singleton instance */
  39     public static final UstDebugInfoSourceAspect INSTANCE = new UstDebugInfoSourceAspect();
  40
  41     private UstDebugInfoSourceAspect() {}
  42
  43     @Override
  44     public String getName() {
  45         return nullToEmptyString(Messages.UstDebugInfoAnalysis_AspectName);
  46     }
  47
  48     @Override
  49     public String getHelpText() {
  50         return nullToEmptyString(Messages.UstDebugInfoAnalysis_AspectHelpText);
  51     }
  52
  53     @Override
  54     public @Nullable TmfCallsite resolve(ITmfEvent event) {
  55         /* This aspect only supports UST traces */
  56         if (!(event.getTrace() instanceof LttngUstTrace)) {
  57             return null;
  58         }
  59
  60         ILttngUstEventLayout layout = ((LttngUstTrace) event.getTrace()).getEventLayout();
  61
  62         /* We need both the vpid and ip contexts */
  63         ITmfEventField vpidField = event.getContent().getField(layout.contextVpid());
  64         ITmfEventField ipField = event.getContent().getField(layout.contextIp());
  65         if (vpidField == null || ipField == null) {
  66             return null;
  67         }
  68         Long vpid = (Long) vpidField.getValue();
  69         Long ip = (Long) ipField.getValue();
  70
  71         /*
  72          * First match the IP to the correct binary or library, by using the
  73          * UstDebugInfoAnalysis.
  74          */
  75         UstDebugInfoAnalysisModule module =
  76                 TmfTraceUtils.getAnalysisModuleOfClass(event.getTrace(),
  77                         UstDebugInfoAnalysisModule.class, UstDebugInfoAnalysisModule.ID);
  78         if (module == null) {
  79             /*
  80              * The analysis is not available for this trace, we won't be
  81              * able to find the information.
  82              */
  83             return null;
  84         }
  85         long ts = event.getTimestamp().getValue();
  86         UstDebugInfoLoadedBinaryFile file = module.getMatchingFile(ts, vpid, ip);
  87         if (file == null) {
  88             return null;
  89         }
  90
  91         long offset;
  92         if (isMainBinary(file)) {
  93             /*
  94              * In the case of the object being the main binary (loaded at a very
  95              * low address), we must pass the actual ip address to addr2line.
  96              */
  97             offset = ip.longValue();
  98         } else {
  99             offset = (ip.longValue() - file.getBaseAddress());
 100         }
 101
 102         if (offset < 0) {
 103             throw new IllegalStateException();
 104         }
 105
 106         Iterable<TmfCallsite> callsites = FileOffsetMapper.getCallsiteFromOffset(new File(file.getFilePath()), offset);
 107
 108         if (callsites == null || Iterables.isEmpty(callsites)) {
 109             return null;
 110         }
 111         /*
 112          * TMF only supports the notion of one callsite per event at the moment.
 113          * We will take the "deepest" one in the stack, which should refer to
 114          * the initial, non-inlined location.
 115          */
 116         return Iterables.getLast(callsites);
 117     }
 118
 119     private static boolean isMainBinary(UstDebugInfoLoadedBinaryFile file) {
 120         /*
 121          * Ghetto binary/library identification for now. It would be possible to
 122          * parse the ELF binary to check if it is position-independent
 123          * (-fPIC/-fPIE) or not.
 124          */
 125         return (!file.getFilePath().endsWith(".so")); //$NON-NLS-1$
 126     }
 127
 128 }