This commit makes the code source compatible across Scala 2.10.3
and https://github.com/scala/scala/pull/3452, which is proposed
for inclusion in Scala 2.11.0-RC1.
We only strictly need the incremental compiler to build on Scala
2.11, as that is integrated into the IDE. But we gain valuable
insight into compiler regressions by building *all* of SBT with
2.11.
We only got there recently (the 0.13 branch of SBT now fully cross
compiles with 2.10.3 and 2.11.0-SNAPSHOT), and this aims to keep
things that way.
Once 2.10 support is dropped, SBT macros will be able to exploit
the new reflection APIs in 2.11 to avoid the need for casting
to compiler internals, which aren't governed by binary compatibility.
This has been prototyped by @xeno-by: https://github.com/sbt/sbt/pull/1121
Since the fix for SI-2066, Scala 2.11 calls logicallyEnclosingMember on the
`x` in the expansion of the task macro:
InitializeInstance.app[[T0[x]](T0[java.io.File], T0[java.io.File]), Seq[java.io.File]]
This exposed the fact that SBT has created `T0` with `NoSymbol` as
the owner. This led to the a SOE.
I will also change the compiler to be more tolerant of this, but we
can observe good discipline in the macro and pick a sensible owner.
Still TODO for auto-plugins/logic:
* property-based tests for logic system
* user documentation
* (optional) 'about plugins' or similar to show more information about the auto-plugins for a project
* (deferred) allow AutoPlugin to inject Commands directly?
* (deferred) provide AutoPlugin functionality to arbitrary scopes instead of just at the Project level?
This is an attempt to provide a decent error message in some cases. However, paths that include
the Java path separator character are just fundamentally problematic and aren't always going to
be cleanly detected.
This requires a Format[T] to be implicitly available at the call site and requires the task
to be referenced statically (not in a settingDyn call). References to previous task values
in the form of a ScopedKey[Task[T]] + Format[T] are collected at setting load time in the
'references' setting. These are used to know which tasks should be persisted (the ScopedKey)
and how to persist them (the Format).
When checking/delegating previous references, rules are slightly different.
A normal reference from a task t in scope s cannot refer to t in s unless
there is an earlier definition of t in s. However, a previous reference
does not have this restriction. This commit modifies validateReferenced
to allow this.
TODO: user documentation
TODO: stable selection of the Format when there are multiple .previous calls on the same task
TODO: make it usable in InputTasks, specifically Parsers
The fix was made possible by the very helpful information provided by @retronym.
This commit does two key things:
1. changes the owner when splicing original trees into new trees
2. ensures the synthetic trees that get spliced into original trees do not need typechecking
Given this original source (from Defaults.scala):
...
lazy val sourceConfigPaths = Seq(
...
unmanagedSourceDirectories := Seq(scalaSource.value, javaSource.value),
...
)
...
After expansion of .value, this looks something like:
unmanagedSourceDirectories := Seq(
InputWrapper.wrapInit[File](scalaSource),
InputWrapper.wrapInit[File](javaSource)
)
where wrapInit is something like:
def wrapInit[T](a: Any): T
After expansion of := we have (approximately):
unmanagedSourceDirectories <<=
Instance.app( (scalaSource, javaSource) ) {
$p1: (File, File) =>
val $q4: File = $p1._1
val $q3: File = $p1._2
Seq($q3, $q4)
}
So,
a) `scalaSource` and `javaSource` are user trees that are spliced into a tuple constructor after being temporarily held in `InputWrapper.wrapInit`
b) the constructed tuple `(scalaSource, javaSource)` is passed as an argument to another method call (without going through a val or anything) and shouldn't need owner changing
c) the synthetic vals $q3 and $q4 need their owner properly set to the anonymous function
d) the references (Idents) $q3 and $q4 are spliced into the user tree `Seq(..., ...)` and their symbols need to be the Symbol for the referenced vals
e) generally, treeCopy needs to be used when substituting Trees in order to preserve attributes, like Types and Positions
changeOwner is called on the body `Seq($q3, $q4)` with the original owner sourceConfigPaths to be changed to the new anonymous function.
In this example, no owners are actually changed, but when the body contains vals or anonymous functions, they will.
An example of the compiler crash seen when the symbol of the references is not that of the vals:
symbol value $q3 does not exist in sbt.Defaults.sourceConfigPaths$lzycompute
at scala.reflect.internal.SymbolTable.abort(SymbolTable.scala:49)
at scala.tools.nsc.Global.abort(Global.scala:254)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.genLoadIdent$1(GenICode.scala:1038)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase.scala$tools$nsc$backend$icode$GenICode$ICodePhase$$genLoad(GenICode.scala:1044)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase$$anonfun$genLoadArguments$1.apply(GenICode.scala:1246)
at scala.tools.nsc.backend.icode.GenICode$ICodePhase$$anonfun$genLoadArguments$1.apply(GenICode.scala:1244)
...
Other problems with the synthetic tree when it is spliced under the original tree often result in type mismatches or some other compiler error that doesn't result in a crash.
If the owner is not changed correctly on the original tree that gets spliced under a synthetic tree, one way it can crash the compiler is:
java.lang.IllegalArgumentException: Could not find proxy for val $q23: java.io.File in List(value $q23, method apply, anonymous class $anonfun$globalCore$5, value globalCore, object Defaults, package sbt, package <root>) (currentOwner= value dir )
...
while compiling: /home/mark/code/sbt/main/src/main/scala/sbt/Defaults.scala
during phase: global=lambdalift, atPhase=constructors
...
last tree to typer: term $outer
symbol: value $outer (flags: <synthetic> <paramaccessor> <triedcooking> private[this])
symbol definition: private[this] val $outer: sbt.BuildCommon
tpe: <notype>
symbol owners: value $outer -> anonymous class $anonfun$87 -> value x$298 -> method derive -> class BuildCommon$class -> package sbt
context owners: value dir -> value globalCore -> object Defaults -> package sbt
...
The problem here is the difference between context owners and the proxy search chain.
As pointed out by @harrah in #705, both beginSource and endSource are
not used in sbt internally for anything meaningful.
We've discussed an option of deprecating those methods but since they
are not doing anything meaningful Mark prefers to have compile-time
error in case somebody implements or calls those methods. I agree with
that hence removal.
Equality is reference equality for classes that have lazy members
(currently Structure and ClassLike) and member equality for everything else.
This avoids the circularity issue due to lazy members.
Forces each class to be either abstract or final, to ensure that
the equals implementation is always correct.
Fixes toString to avoid infinite recursion.
* when mvn does a local 'install', it doesn't update the pom.xml last modified time if the pom.xml content hasn't changed
* an ivy.xml includes publicationDate, so an ivy.xml will always be touched even if the other content hasn't changed
* when Ivy checks if a snapshot is uptodate
+ it sees a SNAPSHOT, so it knows the module metadata and artifacts might change
+ it then checks the lastModified time of the metadata
+ if unchanged, it uses the cached information
+ if useOrigin is effectively false (either it is explicitly false or a resource is remote/isLocal=false),
this means that a new artifact won't be retrieved
* the Ivy IBiblioResolver
+ must be used for Maven repositories for proper behavior (no FileResolver, for example)
+ only returns URLResources, even for file: URLs
+ a FileResource is needed in combination with useOrigin to avoid copying artifacts from .m2/repository/
This commit fixes the above by setting a custom URLRepository on a constructed IBiblioResolver.
This URLRepository returns FileResources for file: URLs and standard URLResources for others.
The returned FileResource has isLocal=true and sbt sets useOrigin=true by default, so the artifacts
are used from the origin.
If it turns out a similar situation happens when mvn publishes to remote repositories, it is likely the fix for
that would be to figure out how to disable the lastModified check on the metadata and always download the metadata.
This would be slower, however.
Josh Suereth
Jason Zaugg
Mark Harrah
Dan Sanduleac
Benjy
Bruno Bieth
Grzegorz Kossakowski
James Roper