sdk/runtime/lib/errors_patch.dart

// Copyright (c) 2012, the Dart 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.

@patch class Error {
  @patch static String _objectToString(Object object) {
    return Object._toString(object);
  }

  @patch static String _stringToSafeString(String string) {
    return JSON.encode(string);
  }

  @patch StackTrace get stackTrace => _stackTrace;

  StackTrace _stackTrace;
}

class _AssertionError extends Error implements AssertionError {
  _AssertionError._create(
      this._failedAssertion, this._url, this._line, this._column);

  static _throwNew(int assertionStart, int assertionEnd)
      native "AssertionError_throwNew";

  static void _checkAssertion(condition, int start, int end) {
    if (condition is Function) {
      condition = condition();
    }
    if (!condition) {
      _throwNew(start, end);
    }
  }

  static void _checkConstAssertion(bool condition, int start, int end) {
    if (!condition) {
      _throwNew(start, end);
    }
  }

  String toString() {
    if (_url == null) {
      return _failedAssertion;
    }
    var columnInfo = "";
    if (_column > 0) {
      // Only add column information if it is valid.
      columnInfo = " pos $_column";
    }
    return "'$_url': Failed assertion: line $_line$columnInfo: "
        "'$_failedAssertion' is not true.";
  }
  final String _failedAssertion;
  final String _url;
  final int _line;
  final int _column;
}

class _TypeError extends _AssertionError implements TypeError {
  _TypeError._create(String url, int line, int column, this._errorMsg)
      : super._create("is assignable", url, line, column);

  static _throwNew(int location,
                   Object src_value,
                   _Type dst_type,
                   String dst_name,
                   String bound_error_msg)
      native "TypeError_throwNew";

  static _throwNewIfNotLoaded(_LibraryPrefix prefix,
                              int location,
                              Object src_value,
                              _Type dst_type,
                              String dst_name,
                              String bound_error_msg) {
    if (!prefix.isLoaded()) {
      _throwNew(location, src_value, dst_type, dst_name, bound_error_msg);
    }
  }

  String toString() => _errorMsg;

  final String _errorMsg;
}

class _CastError extends Error implements CastError {
  _CastError._create(this._url, this._line, this._column, this._errorMsg);

  // A CastError is allocated by TypeError._throwNew() when dst_name equals
  // Symbols::InTypeCast().

  String toString() => _errorMsg;

  // Fields _url, _line, and _column are only used for debugging purposes.
  final String _url;
  final int _line;
  final int _column;
  final String _errorMsg;
}

@patch class FallThroughError {
  FallThroughError._create(this._url, this._line);

  static _throwNew(int case_clause_pos) native "FallThroughError_throwNew";

  @patch String toString() {
    return "'$_url': Switch case fall-through at line $_line.";
  }

  // These new fields cannot be declared final, because a constructor exists
  // in the original version of this patched class.
  String _url;
  int _line;
}

class _InternalError {
  const _InternalError(this._msg);
  String toString() => "InternalError: '${_msg}'";
  final String _msg;
}

@patch class UnsupportedError {
  static _throwNew(String msg) {
    throw new UnsupportedError(msg);
  }
}

@patch class CyclicInitializationError {
  static _throwNew(String variableName) {
    throw new CyclicInitializationError(variableName);
  }
}

@patch class AbstractClassInstantiationError {
  AbstractClassInstantiationError._create(
      this._className, this._url, this._line);

  static _throwNew(int case_clause_pos, String className)
      native "AbstractClassInstantiationError_throwNew";

  @patch String toString() {
    return "Cannot instantiate abstract class $_className: "
           "_url '$_url' line $_line";
  }

  // These new fields cannot be declared final, because a constructor exists
  // in the original version of this patched class.
  String _url;
  int _line;
}

@patch class NoSuchMethodError {
  // The compiler emits a call to _throwNew when it cannot resolve a static
  // method at compile time. The receiver is actually the literal class of the
  // unresolved method.
  static void _throwNew(Object receiver,
                        String memberName,
                        int invocation_type,
                        List arguments,
                        List argumentNames,
                        List existingArgumentNames) {
    int numNamedArguments = argumentNames == null ? 0 : argumentNames.length;
    int numPositionalArguments = arguments == null ? 0 : arguments.length;
    numPositionalArguments -= numNamedArguments;
    List positionalArguments;
    if (numPositionalArguments > 0) {
      // TODO(srdjan): Unresolvable static methods sometimes do not provide the
      // arguments, because the arguments are evaluated but not passed to the
      // throwing stub (see EffectGraphVisitor::BuildThrowNoSuchMethodError and
      // Parser::ThrowNoSuchMethodError)). There is no way to distinguish the
      // case of no arguments from the case of the arguments not being passed
      // in here, though. See https://github.com/dart-lang/sdk/issues/27572
      positionalArguments = arguments.sublist(0, numPositionalArguments);
    }
    Map<Symbol, dynamic> namedArguments = new Map<Symbol, dynamic>();
    for (int i = 0; i < numNamedArguments; i++) {
      var arg_value = arguments[numPositionalArguments + i];
      namedArguments[new Symbol(argumentNames[i])] = arg_value;
    }
    throw new NoSuchMethodError._withType(receiver,
                                          new Symbol(memberName),
                                          invocation_type,
                                          positionalArguments,
                                          namedArguments,
                                          existingArgumentNames);
  }

  static void _throwNewIfNotLoaded(_LibraryPrefix prefix,
                                   Object receiver,
                                   String memberName,
                                   int invocation_type,
                                   List arguments,
                                   List argumentNames,
                                   List existingArgumentNames) {
    if (!prefix.isLoaded()) {
      _throwNew(receiver, memberName, invocation_type, arguments,
                argumentNames, existingArgumentNames);
    }
  }

  // Remember the type from the invocation mirror or static compilation
  // analysis when thrown directly with _throwNew. A negative value means
  // that no information is available.
  final int _invocation_type;

  @patch
  NoSuchMethodError(Object this._receiver,
                    Symbol this._memberName,
                    List this._arguments,
                    Map<Symbol, dynamic> this._namedArguments,
                    [List existingArgumentNames = null])
      : this._existingArgumentNames = existingArgumentNames,
        this._invocation_type = -1;

  // This constructor seems to be called with either strings or
  // values read from another NoSuchMethodError.
  NoSuchMethodError._withType(Object this._receiver,
                              /*String|Symbol*/ memberName,
                              this._invocation_type,
                              List this._arguments,
                              Map<dynamic, dynamic> namedArguments,
                              [List existingArgumentNames = null])
      : this._memberName =
            (memberName is String) ? new Symbol(memberName) : memberName,
        this._namedArguments =
            (namedArguments == null)
                ? null
                : new Map<Symbol, dynamic>.fromIterable(
                    namedArguments.keys,
                    key: (k) => (k is String) ? new Symbol(k) : k,
                    value: (k) => namedArguments[k]),
        this._existingArgumentNames = existingArgumentNames;

  @patch String toString() {
    var level = (_invocation_type >> _InvocationMirror._CALL_SHIFT) &
        _InvocationMirror._CALL_MASK;
    var type = _invocation_type & _InvocationMirror._TYPE_MASK;
    String memberName = (_memberName == null) ? "" :
        internal.Symbol.getUnmangledName(_memberName);

    if (type == _InvocationMirror._LOCAL_VAR) {
      return "NoSuchMethodError: Cannot assign to final variable '$memberName'";
    }

    StringBuffer arguments = new StringBuffer();
    int argumentCount = 0;
    if (_arguments != null) {
      for (; argumentCount < _arguments.length; argumentCount++) {
        if (argumentCount > 0) {
          arguments.write(", ");
        }
        arguments.write(Error.safeToString(_arguments[argumentCount]));
      }
    }
    if (_namedArguments != null) {
      _namedArguments.forEach((Symbol key, var value) {
        if (argumentCount > 0) {
          arguments.write(", ");
        }
        arguments.write(internal.Symbol.getUnmangledName(key));
        arguments.write(": ");
        arguments.write(Error.safeToString(value));
        argumentCount++;
      });
    }
    bool args_mismatch = _existingArgumentNames != null;
    String args_message = args_mismatch ? " with matching arguments" : "";

    String type_str;
    if (type >= 0 && type < 5) {
      type_str = (const ["method", "getter", "setter", "getter or setter",
          "variable"])[type];
    }

    StringBuffer msg_buf = new StringBuffer("NoSuchMethodError: ");
    bool is_type_call = false;
    switch (level) {
      case _InvocationMirror._DYNAMIC: {
        if (_receiver == null) {
          if (args_mismatch) {
            msg_buf.writeln("The null object does not have a $type_str "
                "'$memberName'$args_message.");
          } else {
            msg_buf.writeln("The $type_str '$memberName' was called on null.");
          }
        } else {
          if (_receiver is Function) {
            msg_buf.writeln("Closure call with mismatched arguments: "
                "function '$memberName'");
          } else if (_receiver is _Type && memberName == "call") {
            is_type_call = true;
            String name = _receiver.toString();
            msg_buf.writeln("Attempted to use type '$name' as a function. "
                "Since types do not define a method 'call', this is not "
                "possible. Did you intend to call the $name constructor and "
                "forget the 'new' operator?");
          } else {
            msg_buf.writeln("Class '${_receiver.runtimeType}' has no instance "
                "$type_str '$memberName'$args_message.");
          }
        }
        break;
      }
      case _InvocationMirror._SUPER: {
        msg_buf.writeln("Super class of class '${_receiver.runtimeType}' has "
              "no instance $type_str '$memberName'$args_message.");
        memberName = "super.$memberName";
        break;
      }
      case _InvocationMirror._STATIC: {
        msg_buf.writeln("No static $type_str '$memberName'$args_message "
            "declared in class '$_receiver'.");
        break;
      }
      case _InvocationMirror._CONSTRUCTOR: {
        msg_buf.writeln("No constructor '$memberName'$args_message declared "
            "in class '$_receiver'.");
        memberName = "new $memberName";
        break;
      }
      case _InvocationMirror._TOP_LEVEL: {
        msg_buf.writeln("No top-level $type_str '$memberName'$args_message "
            "declared.");
        break;
      }
    }

    if (level == _InvocationMirror._TOP_LEVEL) {
      msg_buf.writeln("Receiver: top-level");
    } else {
      msg_buf.writeln("Receiver: ${Error.safeToString(_receiver)}");
    }

    if (type == _InvocationMirror._METHOD) {
      String m = is_type_call ? "$_receiver" : "$memberName";
      msg_buf.write("Tried calling: $m($arguments)");
    } else if (argumentCount == 0) {
      msg_buf.write("Tried calling: $memberName");
    } else if (type == _InvocationMirror._SETTER) {
      msg_buf.write("Tried calling: $memberName$arguments");
    } else {
      msg_buf.write("Tried calling: $memberName = $arguments");
    }

    if (args_mismatch) {
      StringBuffer formalParameters = new StringBuffer();
      for (int i = 0; i < _existingArgumentNames.length; i++) {
        if (i > 0) {
          formalParameters.write(", ");
        }
        formalParameters.write(_existingArgumentNames[i]);
      }
      msg_buf.write("\nFound: $memberName($formalParameters)");
    }

    return msg_buf.toString();
  }
}


class _CompileTimeError extends Error {
  final String _errorMsg;
  _CompileTimeError(this._errorMsg);
  String toString() => _errorMsg;
}