add --assert-message flag back

pkg/compiler/lib/src/options.dart

 // Copyright (c) 2016, 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.
 
 library dart2js.src.options;
 
 import '../compiler.dart' show PackagesDiscoveryProvider;
 import 'commandline_options.dart' show Flags;
 
 /// Options used for controlling diagnostic messages.
@@ skipping 111 matching lines @@
 
   /// Whether to disable global type inference.
   final bool disableTypeInference;
 
   /// Whether to emit a .json file with a summary of the information used by the
   /// compiler during optimization. This includes resolution details,
   /// dependencies between elements, results of type inference, and the output
   /// code for each function.
   final bool dumpInfo;
 
+  /// Whether we allow passing an extra argument to `assert`, containing a
+  /// reason for why an assertion fails. (experimental)
+  final bool enableAssertMessage;
+
   /// Whether the user specified a flag to allow the use of dart:mirrors. This
   /// silences a warning produced by the compiler.
   final bool enableExperimentalMirrors;
 
   /// Whether to enable minification
   // TODO(sigmund): rename to minify
   final bool enableMinification;
 
   /// Whether to model which native classes are live based on annotations on the
   /// core libraries. If false, all native classes will be included by default.
@@ skipping 179 matching lines @@
       String buildId: _UNDETERMINED_BUILD_ID,
       Uri deferredMapUri: null,
       bool fatalWarnings: false,
       bool terseDiagnostics: false,
       bool suppressWarnings: false,
       bool suppressHints: false,
       List<String> shownPackageWarnings: null,
       bool disableInlining: false,
       bool disableTypeInference: false,
       bool dumpInfo: false,
+      bool enableAssertMessage: true,
       bool enableExperimentalMirrors: false,
       bool enableMinification: false,
       bool enableNativeLiveTypeAnalysis: true,
       bool enableTypeAssertions: false,
       bool enableUserAssertions: false,
       bool generateCodeWithCompileTimeErrors: false,
       bool generateSourceMap: true,
       bool hasIncrementalSupport: false,
       Uri outputUri: null,
       Uri platformConfigUri: null,
@@ skipping 49 matching lines @@
         buildId: buildId,
         deferredMapUri: deferredMapUri,
         fatalWarnings: fatalWarnings,
         terseDiagnostics: terseDiagnostics,
         suppressWarnings: suppressWarnings,
         suppressHints: suppressHints,
         shownPackageWarnings: shownPackageWarnings,
         disableInlining: disableInlining || hasIncrementalSupport,
         disableTypeInference: disableTypeInference,
         dumpInfo: dumpInfo,
+        enableAssertMessage: enableAssertMessage,
         enableExperimentalMirrors: enableExperimentalMirrors,
         enableMinification: enableMinification,
         enableNativeLiveTypeAnalysis: enableNativeLiveTypeAnalysis,
         enableTypeAssertions: enableTypeAssertions,
         enableUserAssertions: enableUserAssertions,
         generateCodeWithCompileTimeErrors: generateCodeWithCompileTimeErrors,
         generateSourceMap: generateSourceMap,
         hasIncrementalSupport: hasIncrementalSupport,
         outputUri: outputUri,
         platformConfigUri: platformConfigUri ??
@@ skipping 28 matching lines @@
       this.buildId: _UNDETERMINED_BUILD_ID,
       this.deferredMapUri: null,
       this.fatalWarnings: false,
       this.terseDiagnostics: false,
       this.suppressWarnings: false,
       this.suppressHints: false,
       List<String> shownPackageWarnings: null,
       this.disableInlining: false,
       this.disableTypeInference: false,
       this.dumpInfo: false,
+      this.enableAssertMessage: true,
       this.enableExperimentalMirrors: false,
       this.enableMinification: false,
       this.enableNativeLiveTypeAnalysis: false,
       this.enableTypeAssertions: false,
       this.enableUserAssertions: false,
       this.generateCodeWithCompileTimeErrors: false,
       this.generateSourceMap: true,
       this.hasIncrementalSupport: false,
       this.outputUri: null,
       this.platformConfigUri: null,
@@ skipping 35 matching lines @@
       buildId,
       deferredMapUri,
       fatalWarnings,
       terseDiagnostics,
       suppressWarnings,
       suppressHints,
       List<String> shownPackageWarnings,
       disableInlining,
       disableTypeInference,
       dumpInfo,
+      enableAssertMessage,
       enableExperimentalMirrors,
       enableMinification,
       enableNativeLiveTypeAnalysis,
       enableTypeAssertions,
       enableUserAssertions,
       generateCodeWithCompileTimeErrors,
       generateSourceMap,
       hasIncrementalSupport,
       outputUri,
       platformConfigUri,
@@ skipping 36 matching lines @@
         fatalWarnings: fatalWarnings ?? options.fatalWarnings,
         terseDiagnostics: terseDiagnostics ?? options.terseDiagnostics,
         suppressWarnings: suppressWarnings ?? options.suppressWarnings,
         suppressHints: suppressHints ?? options.suppressHints,
         shownPackageWarnings:
             shownPackageWarnings ?? options._shownPackageWarnings,
         disableInlining: disableInlining ?? options.disableInlining,
         disableTypeInference:
             disableTypeInference ?? options.disableTypeInference,
         dumpInfo: dumpInfo ?? options.dumpInfo,
+        enableAssertMessage: enableAssertMessage ?? options.enableAssertMessage,
         enableExperimentalMirrors:
             enableExperimentalMirrors ?? options.enableExperimentalMirrors,
         enableMinification: enableMinification ?? options.enableMinification,
         enableNativeLiveTypeAnalysis: enableNativeLiveTypeAnalysis ??
             options.enableNativeLiveTypeAnalysis,
         enableTypeAssertions:
             enableTypeAssertions ?? options.enableTypeAssertions,
         enableUserAssertions:
             enableUserAssertions ?? options.enableUserAssertions,
         generateCodeWithCompileTimeErrors: generateCodeWithCompileTimeErrors ??
@@ skipping 120 matching lines @@
 }
 
 /// Locations of the platform descriptor files relative to the library root.
 const String _clientPlatform = "lib/dart_client.platform";
 const String _serverPlatform = "lib/dart_server.platform";
 const String _sharedPlatform = "lib/dart_shared.platform";
 
 const String _UNDETERMINED_BUILD_ID = "build number could not be determined";
 const bool _forceIncrementalSupport =
     const bool.fromEnvironment('DART2JS_EXPERIMENTAL_INCREMENTAL_SUPPORT');