LCOV - code coverage report
Current view: top level - stack_trace-1.8.2/lib/src - trace.dart (source / functions) Hit Total Coverage
Test: coverage.lcov Lines: 1 88 1.1 %
Date: 2017-10-10 20:17:03 Functions: 0 0 -

          Line data    Source code
       1             : // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
       2             : // for details. All rights reserved. Use of this source code is governed by a
       3             : // BSD-style license that can be found in the LICENSE file.
       4             : 
       5             : import 'dart:math' as math;
       6             : 
       7             : import 'chain.dart';
       8             : import 'frame.dart';
       9             : import 'lazy_trace.dart';
      10             : import 'unparsed_frame.dart';
      11             : import 'utils.dart';
      12             : import 'vm_trace.dart';
      13             : 
      14             : final _terseRegExp = new RegExp(r"(-patch)?([/\\].*)?$");
      15             : 
      16             : /// A RegExp to match V8's stack traces.
      17             : ///
      18             : /// V8's traces start with a line that's either just "Error" or else is a
      19             : /// description of the exception that occurred. That description can be multiple
      20             : /// lines, so we just look for any line other than the first that begins with
      21             : /// three or four spaces and "at".
      22             : final _v8Trace = new RegExp(r"\n    ?at ");
      23             : 
      24             : /// A RegExp to match indidual lines of V8's stack traces.
      25             : ///
      26             : /// This is intended to filter out the leading exception details of the trace
      27             : /// though it is possible for the message to match this as well.
      28             : final _v8TraceLine = new RegExp(r"    ?at ");
      29             : 
      30             : /// A RegExp to match Firefox and Safari's stack traces.
      31             : ///
      32             : /// Firefox and Safari have very similar stack trace formats, so we use the same
      33             : /// logic for parsing them.
      34             : ///
      35             : /// Firefox's trace frames start with the name of the function in which the
      36             : /// error occurred, possibly including its parameters inside `()`. For example,
      37             : /// `.VW.call$0("arg")@http://pub.dartlang.org/stuff.dart.js:560`.
      38             : ///
      39             : /// Safari traces occasionally don't include the initial method name followed by
      40             : /// "@", and they always have both the line and column number (or just a
      41             : /// trailing colon if no column number is available). They can also contain
      42             : /// empty lines or lines consisting only of `[native code]`.
      43             : final _firefoxSafariTrace = new RegExp(
      44             :     r"^"
      45             :     r"(" // Member description. Not present in some Safari frames.
      46             :     r"([.0-9A-Za-z_$/<]|\(.*\))*" // Member name and arguments.
      47             :     r"@"
      48             :     r")?"
      49             :     r"[^\s]*" // Frame URL.
      50             :     r":\d*" // Line or column number. Some older frames only have a line number.
      51             :     r"$",
      52             :     multiLine: true);
      53             : 
      54             : /// A RegExp to match this package's stack traces.
      55             : final _friendlyTrace =
      56             :     new RegExp(r"^[^\s<][^\s]*( \d+(:\d+)?)?[ \t]+[^\s]+$", multiLine: true);
      57             : 
      58             : /// A stack trace, comprised of a list of stack frames.
      59             : class Trace implements StackTrace {
      60             :   /// The stack frames that comprise this stack trace.
      61             :   final List<Frame> frames;
      62             : 
      63             :   /// The original stack trace from which this trace was parsed.
      64             :   final StackTrace original;
      65             : 
      66             :   /// Returns a human-readable representation of [stackTrace]. If [terse] is
      67             :   /// set, this folds together multiple stack frames from the Dart core
      68             :   /// libraries, so that only the core library method directly called from user
      69             :   /// code is visible (see [Trace.terse]).
      70             :   static String format(StackTrace stackTrace, {bool terse: true}) {
      71           0 :     var trace = new Trace.from(stackTrace);
      72           0 :     if (terse) trace = trace.terse;
      73           0 :     return trace.toString();
      74             :   }
      75             : 
      76             :   /// Returns the current stack trace.
      77             :   ///
      78             :   /// By default, the first frame of this trace will be the line where
      79             :   /// [Trace.current] is called. If [level] is passed, the trace will start that
      80             :   /// many frames up instead.
      81             :   factory Trace.current([int level = 0]) {
      82           0 :     if (level < 0) {
      83           0 :       throw new ArgumentError("Argument [level] must be greater than or equal "
      84             :           "to 0.");
      85             :     }
      86             : 
      87           0 :     var trace = new Trace.from(StackTrace.current);
      88           0 :     return new LazyTrace(() {
      89             :       // JS includes a frame for the call to StackTrace.current, but the VM
      90             :       // doesn't, so we skip an extra frame in a JS context.
      91           0 :       return new Trace(trace.frames.skip(level + (inJS ? 2 : 1)),
      92           0 :           original: trace.original.toString());
      93             :     });
      94             :   }
      95             : 
      96             :   /// Returns a new stack trace containing the same data as [trace].
      97             :   ///
      98             :   /// If [trace] is a native [StackTrace], its data will be parsed out; if it's
      99             :   /// a [Trace], it will be returned as-is.
     100             :   factory Trace.from(StackTrace trace) {
     101             :     // Normally explicitly validating null arguments is bad Dart style, but here
     102             :     // the natural failure will only occur when the LazyTrace is materialized,
     103             :     // and we want to provide an error that's more local to the actual problem.
     104             :     if (trace == null) {
     105           0 :       throw new ArgumentError("Cannot create a Trace from null.");
     106             :     }
     107             : 
     108           5 :     if (trace is Trace) return trace;
     109           0 :     if (trace is Chain) return trace.toTrace();
     110           0 :     return new LazyTrace(() => new Trace.parse(trace.toString()));
     111             :   }
     112             : 
     113             :   /// Parses a string representation of a stack trace.
     114             :   ///
     115             :   /// [trace] should be formatted in the same way as a Dart VM or browser stack
     116             :   /// trace. If it's formatted as a stack chain, this will return the equivalent
     117             :   /// of [Chain.toTrace].
     118             :   factory Trace.parse(String trace) {
     119             :     try {
     120           0 :       if (trace.isEmpty) return new Trace(<Frame>[]);
     121           0 :       if (trace.contains(_v8Trace)) return new Trace.parseV8(trace);
     122           0 :       if (trace.contains("\tat ")) return new Trace.parseJSCore(trace);
     123           0 :       if (trace.contains(_firefoxSafariTrace)) {
     124           0 :         return new Trace.parseFirefox(trace);
     125             :       }
     126           0 :       if (trace.contains(chainGap)) return new Chain.parse(trace).toTrace();
     127           0 :       if (trace.contains(_friendlyTrace)) {
     128           0 :         return new Trace.parseFriendly(trace);
     129             :       }
     130             : 
     131             :       // Default to parsing the stack trace as a VM trace. This is also hit on
     132             :       // IE and Safari, where the stack trace is just an empty string (issue
     133             :       // 11257).
     134           0 :       return new Trace.parseVM(trace);
     135           0 :     } on FormatException catch (error) {
     136           0 :       throw new FormatException('${error.message}\nStack trace:\n$trace');
     137             :     }
     138             :   }
     139             : 
     140             :   /// Parses a string representation of a Dart VM stack trace.
     141           0 :   Trace.parseVM(String trace) : this(_parseVM(trace), original: trace);
     142             : 
     143             :   static List<Frame> _parseVM(String trace) {
     144             :     // Ignore [vmChainGap]. This matches the behavior of
     145             :     // `Chain.parse().toTrace()`.
     146           0 :     var lines = trace.trim().replaceAll(vmChainGap, '').split("\n");
     147             :     var frames = lines
     148           0 :         .take(lines.length - 1)
     149           0 :         .map((line) => new Frame.parseVM(line))
     150           0 :         .toList();
     151             : 
     152             :     // TODO(nweiz): Remove this when issue 23614 is fixed.
     153           0 :     if (!lines.last.endsWith(".da")) {
     154           0 :       frames.add(new Frame.parseVM(lines.last));
     155             :     }
     156             : 
     157             :     return frames;
     158             :   }
     159             : 
     160             :   /// Parses a string representation of a Chrome/V8 stack trace.
     161             :   Trace.parseV8(String trace)
     162           0 :       : this(
     163             :             trace
     164           0 :                 .split("\n")
     165           0 :                 .skip(1)
     166             :                 // It's possible that an Exception's description contains a line that
     167             :                 // looks like a V8 trace line, which will screw this up.
     168             :                 // Unfortunately, that's impossible to detect.
     169           0 :                 .skipWhile((line) => !line.startsWith(_v8TraceLine))
     170           0 :                 .map((line) => new Frame.parseV8(line)),
     171             :             original: trace);
     172             : 
     173             :   /// Parses a string representation of a JavaScriptCore stack trace.
     174             :   Trace.parseJSCore(String trace)
     175           0 :       : this(
     176             :             trace
     177           0 :                 .split("\n")
     178           0 :                 .where((line) => line != "\tat ")
     179           0 :                 .map((line) => new Frame.parseV8(line)),
     180             :             original: trace);
     181             : 
     182             :   /// Parses a string representation of an Internet Explorer stack trace.
     183             :   ///
     184             :   /// IE10+ traces look just like V8 traces. Prior to IE10, stack traces can't
     185             :   /// be retrieved.
     186           0 :   Trace.parseIE(String trace) : this.parseV8(trace);
     187             : 
     188             :   /// Parses a string representation of a Firefox stack trace.
     189             :   Trace.parseFirefox(String trace)
     190           0 :       : this(
     191             :             trace
     192           0 :                 .trim()
     193           0 :                 .split("\n")
     194           0 :                 .where((line) => line.isNotEmpty && line != '[native code]')
     195           0 :                 .map((line) => new Frame.parseFirefox(line)),
     196             :             original: trace);
     197             : 
     198             :   /// Parses a string representation of a Safari stack trace.
     199           0 :   Trace.parseSafari(String trace) : this.parseFirefox(trace);
     200             : 
     201             :   /// Parses a string representation of a Safari 6.1+ stack trace.
     202             :   @Deprecated("Use Trace.parseSafari instead.")
     203           0 :   Trace.parseSafari6_1(String trace) : this.parseSafari(trace);
     204             : 
     205             :   /// Parses a string representation of a Safari 6.0 stack trace.
     206             :   @Deprecated("Use Trace.parseSafari instead.")
     207             :   Trace.parseSafari6_0(String trace)
     208           0 :       : this(
     209             :             trace
     210           0 :                 .trim()
     211           0 :                 .split("\n")
     212           0 :                 .where((line) => line != '[native code]')
     213           0 :                 .map((line) => new Frame.parseFirefox(line)),
     214             :             original: trace);
     215             : 
     216             :   /// Parses this package's string representation of a stack trace.
     217             :   ///
     218             :   /// This also parses string representations of [Chain]s. They parse to the
     219             :   /// same trace that [Chain.toTrace] would return.
     220             :   Trace.parseFriendly(String trace)
     221           0 :       : this(
     222           0 :             trace.isEmpty
     223           0 :                 ? []
     224             :                 : trace
     225           0 :                     .trim()
     226           0 :                     .split("\n")
     227             :                     // Filter out asynchronous gaps from [Chain]s.
     228           0 :                     .where((line) => !line.startsWith('====='))
     229           0 :                     .map((line) => new Frame.parseFriendly(line)),
     230             :             original: trace);
     231             : 
     232             :   /// Returns a new [Trace] comprised of [frames].
     233             :   Trace(Iterable<Frame> frames, {String original})
     234           0 :       : frames = new List<Frame>.unmodifiable(frames),
     235           0 :         original = new StackTrace.fromString(original);
     236             : 
     237             :   /// Returns a VM-style [StackTrace] object.
     238             :   ///
     239             :   /// The return value's [toString] method will always return a string
     240             :   /// representation in the Dart VM's stack trace format, regardless of what
     241             :   /// platform is being used.
     242           0 :   StackTrace get vmTrace => new VMTrace(frames);
     243             : 
     244             :   /// Returns a terser version of [this].
     245             :   ///
     246             :   /// This is accomplished by folding together multiple stack frames from the
     247             :   /// core library or from this package, as in [foldFrames]. Remaining core
     248             :   /// library frames have their libraries, "-patch" suffixes, and line numbers
     249             :   /// removed. If the outermost frame of the stack trace is a core library
     250             :   /// frame, it's removed entirely.
     251             :   ///
     252             :   /// This won't do anything with a raw JavaScript trace, since there's no way
     253             :   /// to determine which frames come from which Dart libraries. However, the
     254             :   /// [`source_map_stack_trace`][source_map_stack_trace] package can be used to
     255             :   /// convert JavaScript traces into Dart-style traces.
     256             :   ///
     257             :   /// [source_map_stack_trace]: https://pub.dartlang.org/packages/source_map_stack_trace
     258             :   ///
     259             :   /// For custom folding, see [foldFrames].
     260           0 :   Trace get terse => foldFrames((_) => false, terse: true);
     261             : 
     262             :   /// Returns a new [Trace] based on [this] where multiple stack frames matching
     263             :   /// [predicate] are folded together.
     264             :   ///
     265             :   /// This means that whenever there are multiple frames in a row that match
     266             :   /// [predicate], only the last one is kept. This is useful for limiting the
     267             :   /// amount of library code that appears in a stack trace by only showing user
     268             :   /// code and code that's called by user code.
     269             :   ///
     270             :   /// If [terse] is true, this will also fold together frames from the core
     271             :   /// library or from this package, simplify core library frames, and
     272             :   /// potentially remove the outermost frame as in [Trace.terse].
     273             :   Trace foldFrames(bool predicate(Frame frame), {bool terse: false}) {
     274             :     if (terse) {
     275             :       var oldPredicate = predicate;
     276             :       predicate = (frame) {
     277           0 :         if (oldPredicate(frame)) return true;
     278             : 
     279           0 :         if (frame.isCore) return true;
     280           0 :         if (frame.package == 'stack_trace') return true;
     281             : 
     282             :         // Ignore async stack frames without any line or column information.
     283             :         // These come from the VM's async/await implementation and represent
     284             :         // internal frames. They only ever show up in stack chains and are
     285             :         // always surrounded by other traces that are actually useful, so we can
     286             :         // just get rid of them.
     287             :         // TODO(nweiz): Get rid of this logic some time after issue 22009 is
     288             :         // fixed.
     289           0 :         if (!frame.member.contains('<async>')) return false;
     290           0 :         return frame.line == null;
     291             :       };
     292             :     }
     293             : 
     294           0 :     var newFrames = <Frame>[];
     295           0 :     for (var frame in frames.reversed) {
     296           0 :       if (frame is UnparsedFrame || !predicate(frame)) {
     297           0 :         newFrames.add(frame);
     298           0 :       } else if (newFrames.isEmpty || !predicate(newFrames.last)) {
     299             :         newFrames
     300           0 :             .add(new Frame(frame.uri, frame.line, frame.column, frame.member));
     301             :       }
     302             :     }
     303             : 
     304             :     if (terse) {
     305           0 :       newFrames = newFrames.map((frame) {
     306           0 :         if (frame is UnparsedFrame || !predicate(frame)) return frame;
     307           0 :         var library = frame.library.replaceAll(_terseRegExp, '');
     308           0 :         return new Frame(Uri.parse(library), null, null, frame.member);
     309           0 :       }).toList();
     310             : 
     311           0 :       if (newFrames.length > 1 && predicate(newFrames.first)) {
     312           0 :         newFrames.removeAt(0);
     313             :       }
     314             :     }
     315             : 
     316           0 :     return new Trace(newFrames.reversed, original: this.original.toString());
     317             :   }
     318             : 
     319             :   /// Returns a human-readable string representation of [this].
     320             :   String toString() {
     321             :     // Figure out the longest path so we know how much to pad.
     322             :     var longest =
     323           0 :         frames.map((frame) => frame.location.length).fold(0, math.max);
     324             : 
     325             :     // Print out the stack trace nicely formatted.
     326           0 :     return frames.map((frame) {
     327           0 :       if (frame is UnparsedFrame) return "$frame\n";
     328           0 :       return '${frame.location.padRight(longest)}  ${frame.member}\n';
     329           0 :     }).join();
     330             :   }
     331             : }

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