src/test/java/com/android/tools/r8/naming/retrace/StackTrace.java - r8 - Git at Google

 // Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.

 package com.android.tools.r8.naming.retrace;

 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
 import static org.junit.Assert.assertTrue;

 import com.android.tools.r8.TestRunResult;
 import com.android.tools.r8.ToolHelper;
 import com.android.tools.r8.ToolHelper.DexVm;
 import com.android.tools.r8.utils.FileUtils;
 import com.android.tools.r8.utils.StringUtils;
 import com.google.common.base.Equivalence;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import org.hamcrest.Description;
 import org.hamcrest.Matcher;
 import org.hamcrest.TypeSafeMatcher;

 class StackTrace {

   public static String AT_PREFIX = "at ";
   public static String TAB_AT_PREFIX = "\t" + AT_PREFIX;

   static class StackTraceLine {
     public final String originalLine;
     public final String className;
     public final String methodName;
     public final String fileName;
     public final int lineNumber;

     public StackTraceLine(
         String originalLine, String className, String methodName, String fileName, int lineNumber) {
       this.originalLine = originalLine;
       this.className = className;
       this.methodName = methodName;
       this.fileName = fileName;
       this.lineNumber = lineNumber;
     }

     public boolean hasLineNumber() {
       return lineNumber >= 0;
     }

     public static StackTraceLine parse(String line) {
       String originalLine = line;

       line = line.trim();
       if (line.startsWith(AT_PREFIX)) {
         line = line.substring(AT_PREFIX.length());
       }

       // Expect only one '(', and only one ')' with an optional ':' in between.
       int parenBeginIndex = line.indexOf('(');
       assertTrue(parenBeginIndex > 0);
       assertEquals(parenBeginIndex, line.lastIndexOf('('));
       int parenEndIndex = line.indexOf(')');
       assertTrue(parenBeginIndex < parenEndIndex);
       assertEquals(parenEndIndex, line.lastIndexOf(')'));
       int colonIndex = line.indexOf(':');
       assertTrue(colonIndex == -1 || (parenBeginIndex < colonIndex && colonIndex < parenEndIndex));
       assertEquals(parenEndIndex, line.lastIndexOf(')'));
       String classAndMethod = line.substring(0, parenBeginIndex);
       int lastDotIndex = classAndMethod.lastIndexOf('.');
       assertTrue(lastDotIndex > 0);
       String className = classAndMethod.substring(0, lastDotIndex);
       String methodName = classAndMethod.substring(lastDotIndex + 1);
       int fileNameEnd = colonIndex > 0 ? colonIndex : parenEndIndex;
       String fileName = line.substring(parenBeginIndex + 1, fileNameEnd);
       int lineNumber =
           colonIndex > 0 ? Integer.parseInt(line.substring(colonIndex + 1, parenEndIndex)) : -1;
       StackTraceLine result =
           new StackTraceLine(originalLine, className, methodName, fileName, lineNumber);
       assertEquals(line, result.toString());
       return result;
     }

     @Override
     public int hashCode() {
       return className.hashCode() * 31
           + methodName.hashCode() * 13
           + fileName.hashCode() * 7
           + lineNumber;
     }

     @Override
     public boolean equals(Object other) {
       if (this == other) {
         return true;
       }
       if (other instanceof StackTraceLine) {
         StackTraceLine o = (StackTraceLine) other;
         return className.equals(o.className)
             && methodName.equals(o.methodName)
             && fileName.equals(o.fileName)
             && lineNumber == o.lineNumber;
       }
       return false;
     }

     @Override
     public String toString() {
       String lineNumberPart = lineNumber >= 0 ? ":" + lineNumber : "";
       return className + '.' + methodName + '(' + fileName + lineNumberPart + ')';
     }
   }

   private final List<StackTraceLine> stackTraceLines;

   private StackTrace(List<StackTraceLine> stackTraceLines) {
     assert stackTraceLines.size() > 0;
     this.stackTraceLines = stackTraceLines;
   }

   public int size() {
     return stackTraceLines.size();
   }

   public StackTraceLine get(int index) {
     return stackTraceLines.get(index);
   }

   public static StackTrace extractFromArt(String stderr) {
     List<StackTraceLine> stackTraceLines = new ArrayList<>();
     List<String> stderrLines = StringUtils.splitLines(stderr);

     // A Dalvik stacktrace looks like this (apparently the bottom frame
     // "dalvik.system.NativeStart.main" is not always present)
     // W(209693) threadid=1: thread exiting with uncaught exception (group=0xf616cb20)  (dalvikvm)
     // java.lang.NullPointerException
     // \tat com.android.tools.r8.naming.retrace.Main.a(:133)
     // \tat com.android.tools.r8.naming.retrace.Main.a(:139)
     // \tat com.android.tools.r8.naming.retrace.Main.main(:145)
     // \tat dalvik.system.NativeStart.main(Native Method)
     //
     // An Art 5.1.1 and 6.0.1 stacktrace looks like this:
     // java.lang.NullPointerException: throw with null exception
     // \tat com.android.tools.r8.naming.retrace.Main.a(:154)
     // \tat com.android.tools.r8.naming.retrace.Main.a(:160)
     // \tat com.android.tools.r8.naming.retrace.Main.main(:166)
     //
     // An Art 7.0.0 and latest stacktrace looks like this:
     // Exception in thread "main" java.lang.NullPointerException: throw with null exception
     // \tat com.android.tools.r8.naming.retrace.Main.a(:150)
     // \tat com.android.tools.r8.naming.retrace.Main.a(:156)
     // \tat com.android.tools.r8.naming.retrace.Main.main(:162)
     int last = stderrLines.size();
     // Skip the bottom frame "dalvik.system.NativeStart.main" if present.
     if (ToolHelper.getDexVm().isOlderThanOrEqual(DexVm.ART_4_4_4_HOST)
         && stderrLines.get(last - 1).contains("dalvik.system.NativeStart.main")) {
       last--;
     }
     // Take all lines from the bottom starting with "\tat ".
     int first = last;
     while (first - 1 >= 0 && stderrLines.get(first - 1).startsWith(TAB_AT_PREFIX)) {
       first--;
     }
     for (int i = first; i < last; i++) {
       stackTraceLines.add(StackTraceLine.parse(stderrLines.get(i)));
     }
     return new StackTrace(stackTraceLines);
   }

   public static StackTrace extractFromJvm(String stderr) {
     return new StackTrace(
         StringUtils.splitLines(stderr).stream()
             .filter(s -> s.startsWith(TAB_AT_PREFIX))
             .map(StackTraceLine::parse)
             .collect(Collectors.toList()));
   }

   public static StackTrace extractFromJvm(TestRunResult result) {
     assertNotEquals(0, result.getExitCode());
     return extractFromJvm(result.getStdErr());
   }

   public StackTrace retrace(String map, Path tempFolder) throws IOException {
     Path mapFile = tempFolder.resolve("map");
     Path stackTraceFile = tempFolder.resolve("stackTrace");
     FileUtils.writeTextFile(mapFile, map);
     FileUtils.writeTextFile(
         stackTraceFile,
         stackTraceLines.stream().map(line -> line.originalLine).collect(Collectors.toList()));
     return StackTrace.extractFromJvm(ToolHelper.runRetrace(mapFile, stackTraceFile));
   }

   public StackTrace filter(Predicate<StackTraceLine> filter) {
     return new StackTrace(stackTraceLines.stream().filter(filter).collect(Collectors.toList()));
   }

   @Override
   public int hashCode() {
     return stackTraceLines.hashCode();
   }

   @Override
   public boolean equals(Object other) {
     if (this == other) {
       return true;
     }
     if (other instanceof StackTrace) {
       return stackTraceLines.equals(((StackTrace) other).stackTraceLines);
     } else {
       return false;
     }
   }

   @Override
   public String toString() {
     return toStringWithPrefix("");
   }

   public String toStringWithPrefix(String prefix) {
     StringBuilder builder = new StringBuilder();
     for (StackTraceLine stackTraceLine : stackTraceLines) {
       builder.append(prefix).append(stackTraceLine).append(System.lineSeparator());
     }
     return builder.toString();
   }

   public abstract static class StackTraceEquivalence extends Equivalence<StackTrace> {
     public abstract Equivalence<StackTrace.StackTraceLine> getLineEquivalence();

     @Override
     protected boolean doEquivalent(StackTrace a, StackTrace b) {
       if (a.stackTraceLines.size() != b.stackTraceLines.size()) {
         return false;
       }
       for (int i = 0; i < a.stackTraceLines.size(); i++) {
         if (!getLineEquivalence().equivalent(a.stackTraceLines.get(i), b.stackTraceLines.get(i))) {
           return false;
         }
       }
       return true;
     }

     @Override
     protected int doHash(StackTrace stackTrace) {
       int hashCode = stackTrace.size() * 13;
       for (StackTrace.StackTraceLine stackTraceLine : stackTrace.stackTraceLines) {
         hashCode += (hashCode << 4) + getLineEquivalence().hash(stackTraceLine);
       }
       return hashCode;
     }
   }

   // Equivalence forwarding to default stack trace comparison.
   public static class EquivalenceFull extends StackTraceEquivalence {

     private static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

       private static final LineEquivalence INSTANCE = new LineEquivalence();

       public static LineEquivalence get() {
         return INSTANCE;
       }

       @Override
       protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
         return a.equals(b);
       }

       @Override
       protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
         return stackTraceLine.hashCode();
       }
     }

     private static final EquivalenceFull INSTANCE = new EquivalenceFull();

     public static EquivalenceFull get() {
       return INSTANCE;
     }

     @Override
     public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
       return LineEquivalence.get();
     }

     @Override
     protected boolean doEquivalent(StackTrace a, StackTrace b) {
       return a.equals(b);
     }

     @Override
     protected int doHash(StackTrace stackTrace) {
       return stackTrace.hashCode();
     }
   }

   // Equivalence comparing stack traces without taking the file name into account.
   public static class EquivalenceWithoutFileName extends StackTraceEquivalence {

     private static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

       private static final LineEquivalence INSTANCE = new LineEquivalence();

       public static LineEquivalence get() {
         return INSTANCE;
       }

       @Override
       protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
         return a.className.equals(b.className)
             && a.methodName.equals(b.methodName)
             && a.lineNumber == b.lineNumber;
       }

       @Override
       protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
         return stackTraceLine.className.hashCode() * 13
             + stackTraceLine.methodName.hashCode() * 7
             + stackTraceLine.lineNumber;
       }
     }

     private static final EquivalenceWithoutFileName INSTANCE = new EquivalenceWithoutFileName();

     public static EquivalenceWithoutFileName get() {
       return INSTANCE;
     }

     @Override
     public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
       return LineEquivalence.get();
     }
   }

   // Equivalence comparing stack traces without taking the file name and line number into account.
   public static class EquivalenceWithoutFileNameAndLineNumber extends StackTraceEquivalence {

     private static final EquivalenceWithoutFileNameAndLineNumber INSTANCE =
         new EquivalenceWithoutFileNameAndLineNumber();

     public static EquivalenceWithoutFileNameAndLineNumber get() {
       return INSTANCE;
     }

     public static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

       private static final LineEquivalence INSTANCE = new LineEquivalence();

       public static LineEquivalence get() {
         return INSTANCE;
       }

       @Override
       protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
         return a.className.equals(b.className) && a.methodName.equals(b.methodName);
       }

       @Override
       protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
         return stackTraceLine.className.hashCode() * 13 + stackTraceLine.methodName.hashCode() * 7;
       }
     }

     @Override
     public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
       return LineEquivalence.get();
     }
   }

   public static class StackTraceMatcherBase extends TypeSafeMatcher<StackTrace> {
     private final StackTrace expected;
     private final StackTraceEquivalence equivalence;
     private final String comparisonDescription;

     private StackTraceMatcherBase(
         StackTrace expected, StackTraceEquivalence equivalence, String comparisonDescription) {
       this.expected = expected;
       this.equivalence = equivalence;
       this.comparisonDescription = comparisonDescription;
     }

     @Override
     public boolean matchesSafely(StackTrace stackTrace) {
       return equivalence.equivalent(expected, stackTrace);
     }

     @Override
     public void describeTo(Description description) {
       description
           .appendText("stacktrace " + comparisonDescription)
           .appendText(System.lineSeparator())
           .appendText(expected.toString());
     }

     @Override
     public void describeMismatchSafely(final StackTrace stackTrace, Description description) {
       description.appendText("stacktrace was " + stackTrace);
       description.appendText(System.lineSeparator());
       if (expected.size() != stackTrace.size()) {
         description.appendText("They have different sizes.");
       } else {
         for (int i = 0; i < expected.size(); i++) {
           if (!equivalence.getLineEquivalence().equivalent(expected.get(i), stackTrace.get(i))) {
             description
                 .appendText("First different entry is index " + i + ":")
                 .appendText(System.lineSeparator())
                 .appendText("Expected: " + expected.get(i))
                 .appendText(System.lineSeparator())
                 .appendText("     Was: " + stackTrace.get(i));
             return;
           }
         }
       }
     }
   }

   public static class StackTraceMatcher extends StackTraceMatcherBase {
     private StackTraceMatcher(StackTrace expected) {
       super(expected, EquivalenceFull.get(), "");
     }
   }

   public static Matcher<StackTrace> isSame(StackTrace stackTrace) {
     return new StackTraceMatcher(stackTrace);
   }

   public static class StackTraceIgnoreFileNameMatcher extends StackTraceMatcherBase {
     private StackTraceIgnoreFileNameMatcher(StackTrace expected) {
       super(expected, EquivalenceWithoutFileName.get(), "(ignoring file name)");
     }
   }

   public static Matcher<StackTrace> isSameExceptForFileName(StackTrace stackTrace) {
     return new StackTraceIgnoreFileNameMatcher(stackTrace);
   }

   public static class StackTraceIgnoreFileNameAndLineNumberMatcher extends StackTraceMatcherBase {
     private StackTraceIgnoreFileNameAndLineNumberMatcher(StackTrace expected) {
       super(
           expected,
           EquivalenceWithoutFileNameAndLineNumber.get(),
           "(ignoring file name and line number)");
     }
   }

   public static Matcher<StackTrace> isSameExceptForFileNameAndLineNumber(StackTrace stackTrace) {
     return new StackTraceIgnoreFileNameAndLineNumberMatcher(stackTrace);
   }
 }
	// Copyright (c) 2018, the R8 project authors. Please see the AUTHORS file
	// for details. All rights reserved. Use of this source code is governed by a
	// BSD-style license that can be found in the LICENSE file.

	package com.android.tools.r8.naming.retrace;

	import static org.junit.Assert.assertEquals;
	import static org.junit.Assert.assertNotEquals;
	import static org.junit.Assert.assertTrue;

	import com.android.tools.r8.TestRunResult;
	import com.android.tools.r8.ToolHelper;
	import com.android.tools.r8.ToolHelper.DexVm;
	import com.android.tools.r8.utils.FileUtils;
	import com.android.tools.r8.utils.StringUtils;
	import com.google.common.base.Equivalence;
	import java.io.IOException;
	import java.nio.file.Path;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.function.Predicate;
	import java.util.stream.Collectors;
	import org.hamcrest.Description;
	import org.hamcrest.Matcher;
	import org.hamcrest.TypeSafeMatcher;

	class StackTrace {

	public static String AT_PREFIX = "at ";
	public static String TAB_AT_PREFIX = "\t" + AT_PREFIX;

	static class StackTraceLine {
	public final String originalLine;
	public final String className;
	public final String methodName;
	public final String fileName;
	public final int lineNumber;

	public StackTraceLine(
	String originalLine, String className, String methodName, String fileName, int lineNumber) {
	this.originalLine = originalLine;
	this.className = className;
	this.methodName = methodName;
	this.fileName = fileName;
	this.lineNumber = lineNumber;
	}

	public boolean hasLineNumber() {
	return lineNumber >= 0;
	}

	public static StackTraceLine parse(String line) {
	String originalLine = line;

	line = line.trim();
	if (line.startsWith(AT_PREFIX)) {
	line = line.substring(AT_PREFIX.length());
	}

	// Expect only one '(', and only one ')' with an optional ':' in between.
	int parenBeginIndex = line.indexOf('(');
	assertTrue(parenBeginIndex > 0);
	assertEquals(parenBeginIndex, line.lastIndexOf('('));
	int parenEndIndex = line.indexOf(')');
	assertTrue(parenBeginIndex < parenEndIndex);
	assertEquals(parenEndIndex, line.lastIndexOf(')'));
	int colonIndex = line.indexOf(':');
	assertTrue(colonIndex == -1 \|\| (parenBeginIndex < colonIndex && colonIndex < parenEndIndex));
	assertEquals(parenEndIndex, line.lastIndexOf(')'));
	String classAndMethod = line.substring(0, parenBeginIndex);
	int lastDotIndex = classAndMethod.lastIndexOf('.');
	assertTrue(lastDotIndex > 0);
	String className = classAndMethod.substring(0, lastDotIndex);
	String methodName = classAndMethod.substring(lastDotIndex + 1);
	int fileNameEnd = colonIndex > 0 ? colonIndex : parenEndIndex;
	String fileName = line.substring(parenBeginIndex + 1, fileNameEnd);
	int lineNumber =
	colonIndex > 0 ? Integer.parseInt(line.substring(colonIndex + 1, parenEndIndex)) : -1;
	StackTraceLine result =
	new StackTraceLine(originalLine, className, methodName, fileName, lineNumber);
	assertEquals(line, result.toString());
	return result;
	}

	@Override
	public int hashCode() {
	return className.hashCode() * 31
	+ methodName.hashCode() * 13
	+ fileName.hashCode() * 7
	+ lineNumber;
	}

	@Override
	public boolean equals(Object other) {
	if (this == other) {
	return true;
	}
	if (other instanceof StackTraceLine) {
	StackTraceLine o = (StackTraceLine) other;
	return className.equals(o.className)
	&& methodName.equals(o.methodName)
	&& fileName.equals(o.fileName)
	&& lineNumber == o.lineNumber;
	}
	return false;
	}

	@Override
	public String toString() {
	String lineNumberPart = lineNumber >= 0 ? ":" + lineNumber : "";
	return className + '.' + methodName + '(' + fileName + lineNumberPart + ')';
	}
	}

	private final List<StackTraceLine> stackTraceLines;

	private StackTrace(List<StackTraceLine> stackTraceLines) {
	assert stackTraceLines.size() > 0;
	this.stackTraceLines = stackTraceLines;
	}

	public int size() {
	return stackTraceLines.size();
	}

	public StackTraceLine get(int index) {
	return stackTraceLines.get(index);
	}

	public static StackTrace extractFromArt(String stderr) {
	List<StackTraceLine> stackTraceLines = new ArrayList<>();
	List<String> stderrLines = StringUtils.splitLines(stderr);

	// A Dalvik stacktrace looks like this (apparently the bottom frame
	// "dalvik.system.NativeStart.main" is not always present)
	// W(209693) threadid=1: thread exiting with uncaught exception (group=0xf616cb20) (dalvikvm)
	// java.lang.NullPointerException
	// \tat com.android.tools.r8.naming.retrace.Main.a(:133)
	// \tat com.android.tools.r8.naming.retrace.Main.a(:139)
	// \tat com.android.tools.r8.naming.retrace.Main.main(:145)
	// \tat dalvik.system.NativeStart.main(Native Method)
	//
	// An Art 5.1.1 and 6.0.1 stacktrace looks like this:
	// java.lang.NullPointerException: throw with null exception
	// \tat com.android.tools.r8.naming.retrace.Main.a(:154)
	// \tat com.android.tools.r8.naming.retrace.Main.a(:160)
	// \tat com.android.tools.r8.naming.retrace.Main.main(:166)
	//
	// An Art 7.0.0 and latest stacktrace looks like this:
	// Exception in thread "main" java.lang.NullPointerException: throw with null exception
	// \tat com.android.tools.r8.naming.retrace.Main.a(:150)
	// \tat com.android.tools.r8.naming.retrace.Main.a(:156)
	// \tat com.android.tools.r8.naming.retrace.Main.main(:162)
	int last = stderrLines.size();
	// Skip the bottom frame "dalvik.system.NativeStart.main" if present.
	if (ToolHelper.getDexVm().isOlderThanOrEqual(DexVm.ART_4_4_4_HOST)
	&& stderrLines.get(last - 1).contains("dalvik.system.NativeStart.main")) {
	last--;
	}
	// Take all lines from the bottom starting with "\tat ".
	int first = last;
	while (first - 1 >= 0 && stderrLines.get(first - 1).startsWith(TAB_AT_PREFIX)) {
	first--;
	}
	for (int i = first; i < last; i++) {
	stackTraceLines.add(StackTraceLine.parse(stderrLines.get(i)));
	}
	return new StackTrace(stackTraceLines);
	}

	public static StackTrace extractFromJvm(String stderr) {
	return new StackTrace(
	StringUtils.splitLines(stderr).stream()
	.filter(s -> s.startsWith(TAB_AT_PREFIX))
	.map(StackTraceLine::parse)
	.collect(Collectors.toList()));
	}

	public static StackTrace extractFromJvm(TestRunResult result) {
	assertNotEquals(0, result.getExitCode());
	return extractFromJvm(result.getStdErr());
	}

	public StackTrace retrace(String map, Path tempFolder) throws IOException {
	Path mapFile = tempFolder.resolve("map");
	Path stackTraceFile = tempFolder.resolve("stackTrace");
	FileUtils.writeTextFile(mapFile, map);
	FileUtils.writeTextFile(
	stackTraceFile,
	stackTraceLines.stream().map(line -> line.originalLine).collect(Collectors.toList()));
	return StackTrace.extractFromJvm(ToolHelper.runRetrace(mapFile, stackTraceFile));
	}

	public StackTrace filter(Predicate<StackTraceLine> filter) {
	return new StackTrace(stackTraceLines.stream().filter(filter).collect(Collectors.toList()));
	}

	@Override
	public int hashCode() {
	return stackTraceLines.hashCode();
	}

	@Override
	public boolean equals(Object other) {
	if (this == other) {
	return true;
	}
	if (other instanceof StackTrace) {
	return stackTraceLines.equals(((StackTrace) other).stackTraceLines);
	} else {
	return false;
	}
	}

	@Override
	public String toString() {
	return toStringWithPrefix("");
	}

	public String toStringWithPrefix(String prefix) {
	StringBuilder builder = new StringBuilder();
	for (StackTraceLine stackTraceLine : stackTraceLines) {
	builder.append(prefix).append(stackTraceLine).append(System.lineSeparator());
	}
	return builder.toString();
	}

	public abstract static class StackTraceEquivalence extends Equivalence<StackTrace> {
	public abstract Equivalence<StackTrace.StackTraceLine> getLineEquivalence();

	@Override
	protected boolean doEquivalent(StackTrace a, StackTrace b) {
	if (a.stackTraceLines.size() != b.stackTraceLines.size()) {
	return false;
	}
	for (int i = 0; i < a.stackTraceLines.size(); i++) {
	if (!getLineEquivalence().equivalent(a.stackTraceLines.get(i), b.stackTraceLines.get(i))) {
	return false;
	}
	}
	return true;
	}

	@Override
	protected int doHash(StackTrace stackTrace) {
	int hashCode = stackTrace.size() * 13;
	for (StackTrace.StackTraceLine stackTraceLine : stackTrace.stackTraceLines) {
	hashCode += (hashCode << 4) + getLineEquivalence().hash(stackTraceLine);
	}
	return hashCode;
	}
	}

	// Equivalence forwarding to default stack trace comparison.
	public static class EquivalenceFull extends StackTraceEquivalence {

	private static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

	private static final LineEquivalence INSTANCE = new LineEquivalence();

	public static LineEquivalence get() {
	return INSTANCE;
	}

	@Override
	protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
	return a.equals(b);
	}

	@Override
	protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
	return stackTraceLine.hashCode();
	}
	}

	private static final EquivalenceFull INSTANCE = new EquivalenceFull();

	public static EquivalenceFull get() {
	return INSTANCE;
	}

	@Override
	public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
	return LineEquivalence.get();
	}

	@Override
	protected boolean doEquivalent(StackTrace a, StackTrace b) {
	return a.equals(b);
	}

	@Override
	protected int doHash(StackTrace stackTrace) {
	return stackTrace.hashCode();
	}
	}

	// Equivalence comparing stack traces without taking the file name into account.
	public static class EquivalenceWithoutFileName extends StackTraceEquivalence {

	private static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

	private static final LineEquivalence INSTANCE = new LineEquivalence();

	public static LineEquivalence get() {
	return INSTANCE;
	}

	@Override
	protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
	return a.className.equals(b.className)
	&& a.methodName.equals(b.methodName)
	&& a.lineNumber == b.lineNumber;
	}

	@Override
	protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
	return stackTraceLine.className.hashCode() * 13
	+ stackTraceLine.methodName.hashCode() * 7
	+ stackTraceLine.lineNumber;
	}
	}

	private static final EquivalenceWithoutFileName INSTANCE = new EquivalenceWithoutFileName();

	public static EquivalenceWithoutFileName get() {
	return INSTANCE;
	}

	@Override
	public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
	return LineEquivalence.get();
	}
	}

	// Equivalence comparing stack traces without taking the file name and line number into account.
	public static class EquivalenceWithoutFileNameAndLineNumber extends StackTraceEquivalence {

	private static final EquivalenceWithoutFileNameAndLineNumber INSTANCE =
	new EquivalenceWithoutFileNameAndLineNumber();

	public static EquivalenceWithoutFileNameAndLineNumber get() {
	return INSTANCE;
	}

	public static class LineEquivalence extends Equivalence<StackTrace.StackTraceLine> {

	private static final LineEquivalence INSTANCE = new LineEquivalence();

	public static LineEquivalence get() {
	return INSTANCE;
	}

	@Override
	protected boolean doEquivalent(StackTrace.StackTraceLine a, StackTrace.StackTraceLine b) {
	return a.className.equals(b.className) && a.methodName.equals(b.methodName);
	}

	@Override
	protected int doHash(StackTrace.StackTraceLine stackTraceLine) {
	return stackTraceLine.className.hashCode() * 13 + stackTraceLine.methodName.hashCode() * 7;
	}
	}

	@Override
	public Equivalence<StackTrace.StackTraceLine> getLineEquivalence() {
	return LineEquivalence.get();
	}
	}

	public static class StackTraceMatcherBase extends TypeSafeMatcher<StackTrace> {
	private final StackTrace expected;
	private final StackTraceEquivalence equivalence;
	private final String comparisonDescription;

	private StackTraceMatcherBase(
	StackTrace expected, StackTraceEquivalence equivalence, String comparisonDescription) {
	this.expected = expected;
	this.equivalence = equivalence;
	this.comparisonDescription = comparisonDescription;
	}

	@Override
	public boolean matchesSafely(StackTrace stackTrace) {
	return equivalence.equivalent(expected, stackTrace);
	}

	@Override
	public void describeTo(Description description) {
	description
	.appendText("stacktrace " + comparisonDescription)
	.appendText(System.lineSeparator())
	.appendText(expected.toString());
	}

	@Override
	public void describeMismatchSafely(final StackTrace stackTrace, Description description) {
	description.appendText("stacktrace was " + stackTrace);
	description.appendText(System.lineSeparator());
	if (expected.size() != stackTrace.size()) {
	description.appendText("They have different sizes.");
	} else {
	for (int i = 0; i < expected.size(); i++) {
	if (!equivalence.getLineEquivalence().equivalent(expected.get(i), stackTrace.get(i))) {
	description
	.appendText("First different entry is index " + i + ":")
	.appendText(System.lineSeparator())
	.appendText("Expected: " + expected.get(i))
	.appendText(System.lineSeparator())
	.appendText(" Was: " + stackTrace.get(i));
	return;
	}
	}
	}
	}
	}

	public static class StackTraceMatcher extends StackTraceMatcherBase {
	private StackTraceMatcher(StackTrace expected) {
	super(expected, EquivalenceFull.get(), "");
	}
	}

	public static Matcher<StackTrace> isSame(StackTrace stackTrace) {
	return new StackTraceMatcher(stackTrace);
	}

	public static class StackTraceIgnoreFileNameMatcher extends StackTraceMatcherBase {
	private StackTraceIgnoreFileNameMatcher(StackTrace expected) {
	super(expected, EquivalenceWithoutFileName.get(), "(ignoring file name)");
	}
	}

	public static Matcher<StackTrace> isSameExceptForFileName(StackTrace stackTrace) {
	return new StackTraceIgnoreFileNameMatcher(stackTrace);
	}

	public static class StackTraceIgnoreFileNameAndLineNumberMatcher extends StackTraceMatcherBase {
	private StackTraceIgnoreFileNameAndLineNumberMatcher(StackTrace expected) {
	super(
	expected,
	EquivalenceWithoutFileNameAndLineNumber.get(),
	"(ignoring file name and line number)");
	}
	}

	public static Matcher<StackTrace> isSameExceptForFileNameAndLineNumber(StackTrace stackTrace) {
	return new StackTraceIgnoreFileNameAndLineNumberMatcher(stackTrace);
	}
	}