Implement fromEnvironment on bool, int, String in dart2js.

sdk/lib/_internal/compiler/implementation/dart2js.dart

 // Copyright (c) 2013, 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.cmdline;
 
 import 'dart:async';
 import 'dart:io'
     show exit, File, FileMode, Platform, RandomAccessFile;
 import 'dart:math' as math;
@@ skipping 94 matching lines @@
   bool explicitOut = false;
   bool wantHelp = false;
   bool wantVersion = false;
   String outputLanguage = 'JavaScript';
   bool stripArgumentSet = false;
   bool analyzeOnly = false;
   bool hasDisallowUnsafeEval = false;
   // TODO(johnniwinther): Measure time for reading files.
   SourceFileProvider inputProvider = new CompilerSourceFileProvider();
   diagnosticHandler = new FormattingDiagnosticHandler(inputProvider);
+  Map<String, dynamic> environment = new Map<String, dynamic>();
 
   passThrough(String argument) => options.add(argument);
 
   if (BUILD_ID != null) {
     passThrough("--build-id=$BUILD_ID");
   }
 
   setLibraryRoot(String argument) {
     libraryRoot = currentDirectory.resolve(extractPath(argument));
   }
@@ skipping 42 matching lines @@
   setAnalyzeOnly(String argument) {
     analyzeOnly = true;
     passThrough(argument);
   }
 
   setVerbose(_) {
     diagnosticHandler.verbose = true;
     passThrough('--verbose');
   }
 
+  addInEnvironment(String argument) {
+    Match m = new RegExp('^-D(.+)=(.+)').firstMatch(argument);

[ahe, 2013/10/30 13:03:09]

Terminate with $.

[Lasse Reichstein Nielsen, 2013/10/30 13:34:48]

Terminating isn't necessary. The last capture is greedt.
Consider not using "." since command line parts can contain newlines and '.'
doesn't match newlines.
For a regexp, I'd recommend
   /^-D([^=])+=/
and then do
 String name = m[1];
 String value = argument.substring(m.end);
Anything after the equals is valid, so there is no need to check it.

Or better yet, avoid regexps entirely (then you only have one problem!):
 if (argument.startsWith("-D")) {
   int eqIndex = argument.indexOf("=", 2);
   if (eqIndex >= 0) {
     String name = argument.substring(2, eqIndex);
     String value = argument.substring(eqIndex + 1);
     .... do stuff ...
   } else {
    // error, no = on the line.
  }

 

[ngeoffray, 2013/10/30 15:13:59]

Done.

+    String name = m[1];
+    String value = m[2];
+    if (value == 'true') {
+      environment[name] = true;

[Lasse Reichstein Nielsen, 2013/10/30 13:34:48]

Why parse the arguments here?
Even if the value is "true", it may be wanted as a string.
For integers, parsing can be wrong. If the argument is "-Dfoo=0x1a", it might
not be intended as an integer, and const String.fromEnvironment("foo") should
return "0x1a".

In other words: The environment can be plain String->String. The constructors
add the interpretation, not the environment itself.

[kasperl, 2013/10/30 13:49:56]

I agree with Lasse here. It seems cleaner to do the interpretation later.

[ngeoffray, 2013/10/30 15:13:59]

Done.

+    } else if (value == 'false') {
+      environment[name] = false;
+    } else {
+      int number = int.parse(value, onError: (_) => null);
+      if (number == null) {
+        environment[name] = value;
+      } else {
+        environment[name] = number;
+      }
+    }
+  }
+
   setCategories(String argument) {
     List<String> categories = extractParameter(argument).split(',');
     Set<String> allowedCategories =
         LIBRARIES.values.map((x) => x.category).toSet();
     allowedCategories.remove('Shared');
     allowedCategories.remove('Internal');
     List<String> allowedCategoriesList =
         new List<String>.from(allowedCategories);
     allowedCategoriesList.sort();
     if (categories.contains('all')) {
@@ skipping 81 matching lines @@
     new OptionHandler('--analyze-all', passThrough),
     new OptionHandler('--analyze-only', setAnalyzeOnly),
     new OptionHandler('--analyze-signatures-only', passThrough),
     new OptionHandler('--disable-native-live-type-analysis', passThrough),
     new OptionHandler('--categories=.*', setCategories),
     new OptionHandler('--global-js-name=.*', checkGlobalName),
     new OptionHandler('--disable-type-inference', passThrough),
     new OptionHandler('--terse', passThrough),
     new OptionHandler('--disallow-unsafe-eval',
                       (_) => hasDisallowUnsafeEval = true),
+    new OptionHandler('-D.+=.+', addInEnvironment),
 
     // The following two options must come last.
     new OptionHandler('-.*', (String argument) {
       helpAndFail('Error: Unknown option "$argument".');
     }),
     new OptionHandler('.*', (String argument) {
       arguments.add(nativeToUriPath(argument));
     })
   ];
 
@@ skipping 116 matching lines @@
       if (isPrimaryOutput) {
         totalCharactersWritten += charactersWritten;
       }
     }
 
     return new EventSinkWrapper(writeStringSync, onDone);
   }
 
   return api.compile(uri, libraryRoot, packageRoot,
               inputProvider, diagnosticHandler,
-              options, outputProvider)
+              options, outputProvider, environment)
             .then(compilationDone);
 }
 
 class EventSinkWrapper extends EventSink<String> {
   var onAdd, onClose;
 
   EventSinkWrapper(this.onAdd, this.onClose);
 
   void add(String data) => onAdd(data);
 
@@ skipping 49 matching lines @@
   -c        Insert runtime type checks and enable assertions (checked mode).
   -h        Display this message (add -v for information about all options).''');
 }
 
 void verboseHelp() {
   print(r'''
 Usage: dart2js [options] dartfile
 
 Compiles Dart to JavaScript.
 
 Supported options:

[ahe, 2013/10/30 13:03:09]

Please update the documentation.

[ngeoffray, 2013/10/30 15:13:59]

Done.

   -o <file>, --out=<file>
     Generate the output into <file>.
 
   -c, --enable-checked-mode, --checked
     Insert runtime type checks and enable assertions (checked mode).
 
   -h, /h, /?, --help
     Display this message (add -v for information about all options).
 
   -v, --verbose
@@ skipping 105 matching lines @@
     try {
       var trace = getAttachedStackTrace(exception);
       if (trace != null) {
         print(trace);
       }
     } finally {
       exit(253); // 253 is recognized as a crash by our test scripts.
     }
   });
 }