FSC should check classpath files for changes

[scabug]

Aladdin: [http://scala-webapps.epfl.ch/bugtracking/contribs/display.do?id=768 contrib 768]

== Code ==

edit test.java:

   class Foo {
     public static void foo(int x) {}
   }

compile test.java:

   > javac test.java

edit test.scala:

   object Bar {
     Foo.foo(0)
   }

compile test.scala with FSC:

   > fsc -reset
   > fsc -cp . test.scala

edit test.java:

   class Foo {
     public static void foo(String x) {}
   }

compile test.java:

   > javac test.java

edit test.scala:

   object Bar {
     Foo.foo("test")
   }

compile test.scala with FSC:

   > fsc -cp . test.scala

== What happened ==

Last call to FSC results in:

test.scala:2: error: type mismatch;
 found   : java.lang.String("1")
 required: Int
        Foo.foo("1")
                ^
one error found

FSC is cacheing the first version of the java-compiled classfile. This bug can be quite difficult to track down if you're not expecting it!

== What expected ==

FSC should keep track of the last modification date of all external classfiles it reads in, and reload those with a more recent modification date than that stored.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-84?orig=1
Reporter: @michelou

[scabug]

@odersky said:
Milestone postponed deleted

[SethTisue]

fsc is unmaintained and likely to be removed entirely