dotty.tools.dotc.sbt

Utilities to deal with xsbti.api.

Mostly comes from https://github.com/sbt/zinc/blob/c46643f3e68d7d4f270bf318e3f150f5a59c0aab/internal/zinc-apiinfo/src/main/scala/xsbt/api/APIUtil.scala

Extract the dependency information of a compilation unit.

To understand why we track the used names see the section "Name hashing algorithm" in http://www.scala-sbt.org/0.13/docs/Understanding-Recompilation.html To understand why we need to track dependencies introduced by inheritance specially, see the subsection "Dependencies introduced by member reference and inheritance" in the "Name hashing algorithm" section.

Record dependencies using addUsedName/addClassDependency and inform Zinc using sendToZinc().

Note: As an alternative design choice, we could directly call the appropriate callback as we record each dependency, this way we wouldn't need to record them locally and we could get rid of sendToZinc(), but this may be less efficient since it would mean calling classNameAsString on each call to addUsedName rather than once per class.

This phase sends a representation of the API of classes to sbt via callbacks.

This is used by sbt for incremental recompilation.

See the documentation of ExtractAPICollector, ExtractDependencies, ExtractDependenciesCollector and http://www.scala-sbt.org/1.x/docs/Understanding-Recompilation.html for more information on incremental recompilation.

The following flags affect this phase: -Yforce-sbt-phases -Ydump-sbt-inc

This phase sends information on classes' dependencies to sbt via callbacks.

This is used by sbt for incremental recompilation. Briefly, when a file changes sbt will recompile it, if its API has changed (determined by what ExtractAPI sent) then sbt will determine which reverse-dependencies (determined by what ExtractDependencies sent) of the API have to be recompiled depending on what changed.

See the documentation of ExtractDependenciesCollector, ExtractAPI, ExtractAPICollector and http://www.scala-sbt.org/0.13/docs/Understanding-Recompilation.html for more information on how sbt incremental compilation works.

The following flags affect this phase: -Yforce-sbt-phases