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.
The startup script should set sbt.cygwin=true if running from cygwin.
This will set the terminal type properly for JLine if not already set.
If sbt.cygwin=false or unset and os.name includes "windows", JAnsi is
downloaded by the launcher and installed on standard out/err.
The value for jline.terminal is transformed from explicit jline.X to
the basic types "windows", "unix", or "none". Now that sbt uses JLine
2.0, these types are understood by both sbt's JLine and Scala's.
Older Scala versions shaded the classes but not the terminal property
so both couldn't be configured with a class name at the same time.
Set sbt.task.timings=true to print timings for tasks.
This sample progress handler shows how to get names for tasks and
deal with flatMapped tasks. There are still some tasks that make
it through as anonymous, which needs to be investigated.
A setting to provide a custom handler should come in a subsequent commit.
Support a definitive flag for Failure that ignores later failures
instead of appending them. This is useful to override the default
behavior of listing the failures of alternative parsers.
Needed an explicit type in PMap to workaround an error.
Need to drop tuple assignment of parser.parsed in input task macro as a workaround
for macro/resetAllAttrs/pattern matching/annotation issue in RC1.
1. Hyphenated labels are still accepted when parsing scoped keys (so 'sbt test-only' still works)
There is currently no timeline for removing this support for hyphenated keys.
2. Only camelCase is shown for tab completion.
3. AttributeKey.rawLabel provides the unnormalized label.
This should only be used to implement support for accepting hyphenated keys as input for compatibility.
4. AttributeKey.normLabel provides the normalized label (hyphenated converted to camelCase)
Similar to task macros, the parsed value is accessed by calling `parsed`
on a Parser[T], Initialize[Parser[T]], or Initialize[State => Parser[T]].
Values of tasks and settings may be accessed as usual via `value`.
That is, implement Initialize[Task[T]].flatten correctly.
This requires preserving the transformations applied in a scope so that
they can be applied to an Initialize value after static settings have been
evaluated.
* use normal TypeTree constructor
* remove unnecessary 'with Singleton' in macro utility
* integrate changes suggested by @xeno-by
* add refVar back and call asTypeConstructor instead of asType to refer to a type variable
1. KList[M[_]] now instead of KList[HL <: HList, M[_]]
a. head, tail work properly in this variant
b. disadvantage is that full type not easily transformed to new type constructor
2. AList abstracts on K[L[x]], a higher order type constructor.
A. Instances written for:
a. KList
b. Seq[M[T]] for a fixed T
c. TupleN
d. single values
e. operate on one type constructor when nested
B. Main disadvantage is type inference. It just doesn't happen for K[L[x]].
This is mitigated by AList being used internally and rarely needing to construct a K.
* split several source files
* move base settings sources (Scope, Structure, ...) into main/settings/
* breaks cycles. In particular, setting system moved from Project to Def
alias only parses the right hand side for tab completion help.
The assignment should happen whether or not the parse is successful because the
context may change by the time the alias is actually evaluated.
In particular, the 'set' command uses the loaded project for tab completion in 0.12.1.
When a .sbtrc file is processed, the project has not been loaded yet, so aliases
involving set fail. Wrapping the rhs in failOnException addresses this.
In the unsupported terminal mode, JLine treats a broken
stdin as an endless stream of empty lines. This is problematic
for idea-sbt-plugin: if the IntelliJ process is forcibly killed
and leaves the child SBT process running, it consumes considerable
CPU processing these.
Patching JLine itself would be the cleanest solution (the change
has already been applied to JLine 2), but I've shied away from that
and instead wrapped the InputStream that is read by JLine to
intercept the result of -1 from read(). When this happens, the
flat `inputEof` is set to true.
Mark Harrah
Dan Sanduleac
Benjy
Bruno Bieth
James Roper
cheeseng
Alex Dupre
Paolo G. Giarrusso
Anthony
Grzegorz Kossakowski
Jason Zaugg
Eugene Vigdorchik