This way we have a little bit more clear separation
between compiler phase logic and the core logic responsible for
processing each compilation unit and extracting an api for it.
As added benefit, we have a little bit less of mutable state
(e.g. sourceFile doesn't need to be a var anymore).
The API extraction logic contains some internal caches that are
required for correctness. It wasn't very clear if they have to
be maintained during entire phase run or just during single compilation
unit processing. It looks like they have to be maintained during
single compilation unit processing and refactored code both
documents that contracts and implements it in the API phase.
Move collection (a class `Compat`) of compatibility hacks into separate
file. This aids understanding of the code as both Analyzer and API make
use of that class and keeping it `Analyzer.scala` file suggested that
it's used only by Analyzer.
Incremental compiler didn't have any explicit logic to handle
cancelled compilation so it would go into inconsistent state.
Specifically, what would happen is that it would treat cancelled
compilation as a compilation that finished normally and try to
produce a new Analysis object out of partial information collected
in AnalysisCallback. The most obvious outcome would be that the
new Analysis would contain latest hashes for source files. The
next time incremental compiler was asked to recompile the same files
that it didn't recompile due to cancelled compilation it would think
they were already successfully compiled and would do nothing.
We fix that problem by following the same logic that handles compilation
errors, cleans up partial results (produced class files) and makes sure
that no Analysis is created out of broken state.
We do that by introducing a new exception `CompileCancelled`
and throwing it at the same spot as an exception signalizing compilation
errors is being thrown. We also modify `IncrementalCompile` to
catch that exception and gracefully return as there was no compilation
invoked.
NOTE: In case there were compilation errors reported _before_
compilation cancellations was requested we'll still report them
using an old mechanism so partial errors are not lost in case
of cancelled compilation.
In summary this commit:
* drops type normalization in api phase but keeps dealiasing
* fixes#736 and marks corresponding test as passing
I discussed type normalization with @adriaanm and according to him
sbt shouldn't call that method. The purpose of this method to
convert to a form that subtyping algorithm expects. Sbt doesn't need
to call it and it's fairly expensive in some cases.
Dropping type normalization also fixes#726 by not running into
stale cache in Scala compiler problem described in SI-7361.
The infrastructure for resident compilation still exists,
but the actual scalac-side code that was backported is removed.
Future work on using a resident scalac will use that invalidation
code directly from scalac anyway.
While trying to determine binary dependencies sbt lookups class files
corresponding to symbols. It tried to do that for packages and most of the
time would fail because packages don't have corresponding class file
generated. However, in case of case insensitive file system, combined
with special nesting structure you could get spurious dependency.
See added test case for an example of such structure.
The remedy is to never even try to locate class files corresponding to
packages.
Fixes#620.
Grzegorz Kossakowski
Mark Harrah
Jason Zaugg