Issue 4262. Support for --version in dart_analyzer

Issue 4262. Support for --version in dart_analyzer
http://code.google.com/p/dart/issues/detail?id=4262

Also fix for using "dartc" in usage text.
http://code.google.com/p/dart/issues/detail?id=4261


R=brianwilkerson@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=10084

[Brian Wilkerson, 2012-07-31 19:28:24]

LGTM, though I'd prefer to have the error messages changed

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
File compiler/java/com/google/dart/compiler/DartCompiler.java (right):

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
compiler/java/com/google/dart/compiler/DartCompiler.java:1362:
System.out.println("dart_analyzer #" + revision);
I think it would be better to have a message like:

  dart_analyzer version {revision}

for the normal case and a message like:

  dart_analyzer version unknown
  Could not find the SDK, please set the DART_SDK environment variable or
  use the --dart-sdk command-line option.

for the error case. (Of course, it might be better to distinguish between not
having a path and having a path to an invalid SDK, but that wouldn't be easy
given the current structure of the code.)

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
compiler/java/com/google/dart/compiler/DartCompiler.java:1366: * @return the
numeric revision of SDK, may be <code>null</code> if can not find.
nit: "can not" --> "cannot"

[scheglov, 2012-07-31 19:39:06]

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
File compiler/java/com/google/dart/compiler/DartCompiler.java (right):

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
compiler/java/com/google/dart/compiler/DartCompiler.java:1362:
System.out.println("dart_analyzer #" + revision);

> I think it would be better to have a message like:
> 
>   dart_analyzer version {revision}

OK

> 
> for the normal case and a message like:
> 
>   dart_analyzer version unknown
>   Could not find the SDK, please set the DART_SDK environment variable or
>   use the --dart-sdk command-line option.

Actually dart_analyzer script will print error like this is can not find SDK,
even before running Java code.

https://chromiumcodereview.appspot.com/10825112/diff/1/compiler/java/com/goog...
compiler/java/com/google/dart/compiler/DartCompiler.java:1366: * @return the
numeric revision of SDK, may be <code>null</code> if can not find.
On 2012/07/31 19:28:25, Brian Wilkerson wrote:
> nit: "can not" --> "cannot"

Done.