Implement fromEnvironment on bool, int, String in dart2js.

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

Index: sdk/lib/_internal/compiler/implementation/dart2js.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/dart2js.dart	(revision 29517)
+++ sdk/lib/_internal/compiler/implementation/dart2js.dart	(working copy)
@@ -112,6 +112,7 @@
   // 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);
 
@@ -174,6 +175,24 @@
     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 =
@@ -275,6 +294,7 @@
     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) {
@@ -411,7 +431,7 @@
 
   return api.compile(uri, libraryRoot, packageRoot,
               inputProvider, diagnosticHandler,
-              options, outputProvider)
+              options, outputProvider, environment)
             .then(compilationDone);
 }