lttng/org.eclipse.tracecompass.lttng2.ust.core/src/org/eclipse/tracecompass/internal/lttng2/ust/core/analysis/debuginfo/FileOffsetMapper.java

   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.internal.lttng2.ust.core.analysis.debuginfo;
  11
  12 import static org.eclipse.tracecompass.common.core.NonNullUtils.checkNotNull;
  13
  14 import java.io.BufferedReader;
  15 import java.io.File;
  16 import java.io.IOException;
  17 import java.io.InputStreamReader;
  18 import java.nio.file.Files;
  19 import java.util.Arrays;
  20 import java.util.LinkedList;
  21 import java.util.List;
  22 import java.util.stream.Collectors;
  23
  24 import org.eclipse.jdt.annotation.Nullable;
  25 import org.eclipse.tracecompass.tmf.core.event.lookup.TmfCallsite;
  26
  27 /**
  28  * Utility class to get file name, function/symbol name and line number from a
  29  * given offset. In TMF this is represented as a {@link TmfCallsite}.
  30  *
  31  * @author Alexandre Montplaisir
  32  */
  33 public final class FileOffsetMapper {
  34
  35     private static final String DISCRIMINATOR = "\\(discriminator.*\\)";
  36     private static final String ADDR2LINE_EXECUTABLE = "addr2line"; //$NON-NLS-1$
  37
  38     private FileOffsetMapper() {}
  39
  40     /**
  41      * Generate the callsites from a given binary file and address offset.
  42      *
  43      * Due to function inlining, it is possible for one offset to actually have
  44      * multiple call sites. This is why we can return more than one callsite per
  45      * call.
  46      *
  47      * @param file
  48      *            The binary file to look at
  49      * @param offset
  50      *            The memory offset in the file
  51      * @return The list of callsites corresponding to the offset, reported from
  52      *         the "highest" inlining location, down to the initial definition.
  53      */
  54     public static @Nullable Iterable<TmfCallsite> getCallsiteFromOffset(File file, long offset) {
  55         if (!Files.exists((file.toPath()))) {
  56             return null;
  57         }
  58         return getCallsiteFromOffsetWithAddr2line(file, offset);
  59     }
  60
  61     private static @Nullable Iterable<TmfCallsite> getCallsiteFromOffsetWithAddr2line(File file, long offset) {
  62         List<TmfCallsite> callsites = new LinkedList<>();
  63
  64         // FIXME Could eventually use CDT's Addr2line class once it imlements --inlines
  65         List<String> output = getOutputFromCommand(checkNotNull(Arrays.asList(
  66                 ADDR2LINE_EXECUTABLE, "-i", "-e", file.toString(), "0x" + Long.toHexString(offset))));  //$NON-NLS-1$//$NON-NLS-2$ //$NON-NLS-3$
  67
  68         if (output == null) {
  69             /* Command returned an error */
  70             return null;
  71         }
  72
  73         for (String outputLine : output) {
  74             // Remove discriminator part, for example: /build/buildd/glibc-2.21/elf/dl-object.c:78 (discriminator 8)
  75             outputLine = outputLine.replaceFirst(DISCRIMINATOR, "").trim(); //$NON-NLS-1$
  76
  77             String[] elems = outputLine.split(":"); //$NON-NLS-1$
  78             String fileName = elems[0];
  79             if (fileName.equals("??")) { //$NON-NLS-1$
  80                 continue;
  81             }
  82             long lineNumber = Long.parseLong(elems[1]);
  83
  84             callsites.add(new TmfCallsite(fileName, null, lineNumber));
  85         }
  86
  87         return callsites;
  88     }
  89
  90     private static @Nullable List<String> getOutputFromCommand(List<String> command) {
  91         try {
  92             ProcessBuilder builder = new ProcessBuilder(command);
  93             builder.redirectErrorStream(true);
  94
  95             Process p = builder.start();
  96             BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
  97             int ret = p.waitFor();
  98             List<String> lines = br.lines().collect(Collectors.toList());
  99
 100             return (ret == 0 ? lines : null);
 101
 102         } catch (IOException | InterruptedException e) {
 103             return null;
 104         }
 105     }
 106 }