ammonite.compiler.AmmonitePlugin.scala Maven / Gradle / Ivy
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package ammonite.compiler
import ammonite.util.{ImportData, Name, Util}
import scala.reflect.NameTransformer
import scala.tools.nsc._
import scala.tools.nsc.plugins.{Plugin, PluginComponent}
import scala.reflect.internal.util._
/**
* Used to capture the names in scope after every execution, reporting them
* to the `output` function. Needs to be a compiler plugin so we can hook in
* immediately after the `typer`
*/
class AmmonitePlugin(g: scala.tools.nsc.Global,
output: Seq[ImportData] => Unit,
usedEarlierDefinitions: Seq[String] => Unit,
userCodeNestingLevel: => Int,
topWrapperLen: => Int,
lineNumberModifier: Boolean) extends Plugin{
val name: String = "AmmonitePlugin"
val global: Global = g
val description: String = "Extracts the names in scope for the Ammonite REPL to use"
val components: List[PluginComponent] = {
var components = List.empty[PluginComponent]
if (lineNumberModifier) {
val modifier = new PluginComponent {
val global = g
val runsAfter = List("parser")
override val runsBefore = List("namer")
val phaseName = "FixLineNumbers"
def newPhase(prev: Phase): Phase = new g.GlobalPhase(prev) {
def name = phaseName
def apply(unit: g.CompilationUnit): Unit = {
val things = global.currentRun.units.map(_.source.path).toList
LineNumberModifier(g)(unit, topWrapperLen)
}
}
}
components = modifier :: components
}
val main =
new PluginComponent {
val global = g
val runsAfter = List("typer")
override val runsBefore = List("patmat")
val phaseName = "AmmonitePhase"
def newPhase(prev: Phase): Phase = new g.GlobalPhase(prev) {
def name = phaseName
def apply(unit: g.CompilationUnit): Unit = {
val things = global.currentRun.units.map(_.source.path).toList
AmmonitePlugin(g)(
unit, output, usedEarlierDefinitions, userCodeNestingLevel, topWrapperLen
)
}
}
}
main :: components
}
}
object AmmonitePlugin{
var count = 0
def apply(g: Global)
(unit: g.CompilationUnit,
output: Seq[ImportData] => Unit,
usedEarlierDefinitions: Seq[String] => Unit,
userCodeNestingLevel: => Int,
topWrapperLen: => Int) = {
count += 1
def decode(t: g.Tree) = {
val sym = t.symbol
(sym.isType, sym.decodedName, sym.decodedName, Seq())
}
def saneSym(sym: g.Symbol): Boolean = {
!sym.name.decoded.contains('$') &&
sym.exists &&
!sym.isPrivate &&
!sym.isProtected &&
sym.isPublic &&
!CompilerUtil.ignoredSyms(sym.toString) &&
!CompilerUtil.ignoredNames(sym.name.decoded)
}
val stats = {
val nestingLevel = userCodeNestingLevel
assert(nestingLevel >= 0)
(0 until nestingLevel).foldLeft(unit.body.children.last.children)((res, _) =>
res.last.asInstanceOf[g.ImplDef].impl.body
)
}
userCodeNestingLevel match {
case 1 =>
/*
* We don't try to determine what previous commands are actually used here.
* userCodeNestingLevel == 1 likely corresponds to the default object-based
* code wrapper, which doesn't rely on the actually used previous commands.
*/
case 2 =>
/*
* For userCodeNestingLevel >= 2, we list the variables from the first wrapper
* used from the user code.
*
* E.g. if, after wrapping, the code looks like
* ```
* class cmd2 {
*
* val cmd0 = ???
* val cmd1 = ???
*
* import cmd0.{
* n
* }
*
* class Helper {
* // user-typed code
* val n0 = n + 1
* }
* }
* ```
* this would process the tree of `val n0 = n + 1`, find `n` as a tree like
* `cmd2.this.cmd0.n`, and put `cmd0` in `uses`.
*/
val wrapperSym = unit.body.children.last.children
.last.asInstanceOf[g.ImplDef].symbol
val uses0 = for {
tree <- stats
names <- tree.collect {
case g.Select(node, g.TermName(name)) if node.symbol == wrapperSym =>
name :: Nil
case tt @ g.TypeTree() =>
tt.tpe.collect {
case g.SingleType(pre, sym) if pre.typeSymbol == wrapperSym =>
sym.name.decoded
}
}
name <- names
} yield name
usedEarlierDefinitions(uses0.distinct)
}
val symbols = stats.filter(x => !Option(x.symbol).exists(_.isPrivate))
.foldLeft(List.empty[(Boolean, String, String, Seq[Name])]){
// These are all the ways we want to import names from previous
// executions into the current one. Most are straightforward, except
// `import` statements for which we make use of the typechecker to
// resolve the imported names
case (ctx, t @ g.Import(expr, selectors)) =>
def rec(expr: g.Tree): List[(g.Name, g.Symbol)] = {
expr match {
case s @ g.Select(lhs, _) => (s.symbol.name -> s.symbol) :: rec(lhs)
case i @ g.Ident(name) => List(name -> i.symbol)
case t @ g.This(pkg) => List(pkg -> t.symbol)
}
}
val (nameList, symbolList) = rec(expr).reverse.unzip
// Note: we need to take the symbol on the left-most name and get it's
// `.fullName`. Otherwise if we're in
//
// ```
// package foo.bar.baz
// object Wrapper{val x = ...; import x._}
// ```
//
// The import will get treated as from `Wrapper.x`, but the person
// running that import will not be in package `foo.bar.baz` and will
// not be able to find `Wrapper`! Thus we need to get the full name.
// In cases where the left-most name is a top-level package,
// `.fullName` is basically a no-op and it works as intended.
//
// Apart from this, all other imports should resolve either to one
// of these cases or importing-from-an-existing import, both of which
// should work without modification
val headFullPath = NameTransformer.decode(symbolList.head.fullName).split('.').map(Name(_))
// prefix package imports with `_root_` to try and stop random
// variables from interfering with them. If someone defines a value
// called `_root_`, this will still break, but that's their problem
val rootPrefix = if(symbolList.head.isPackage) Seq(Name("_root_")) else Nil
val tailPath = nameList.tail.map(_.decoded).map(Name(_))
val prefix = rootPrefix ++ headFullPath ++ tailPath
/**
* A map of each name importable from `expr`, to a `Seq[Boolean]`
* containing a `true` if there's a type-symbol you can import, `false`
* if there's a non-type symbol and both if there are both type and
* non-type symbols that are importable for that name
*/
val importableIsTypes =
expr.tpe
.members
.filter(saneSym(_))
.groupBy(_.name.decoded)
.mapValues(_.map(_.isType).toVector)
val renamings = for{
t @ g.ImportSelector(name, _, rename, _) <- selectors
isType <- importableIsTypes.getOrElse(name.decode, Nil) // getOrElse just in case...
} yield Option(rename).map(x => name.decoded -> (isType, x.decoded))
val renameMap = renamings.flatten.map(_.swap).toMap
val info = CompilerCompatibility.importInfo(g)(t)
val symNames = for {
sym <- info.allImportedSymbols
if saneSym(sym)
} yield {
(sym.isType, sym.decodedName)
}
val syms = for{
// For some reason `info.allImportedSymbols` does not show imported
// type aliases when they are imported directly e.g.
//
// import scala.reflect.macros.Context
//
// As opposed to via import scala.reflect.macros._.
// Thus we need to combine allImportedSymbols with the renameMap
(isType, sym) <- (symNames.toList ++ renameMap.keys).distinct
} yield {
(isType, renameMap.getOrElse((isType, sym), sym), sym, prefix)
}
syms ::: ctx
case (ctx, t @ g.DefDef(_, _, _, _, _, _)) => decode(t) :: ctx
case (ctx, t @ g.ValDef(_, _, _, _)) => decode(t) :: ctx
case (ctx, t @ g.ClassDef(_, _, _, _)) => decode(t) :: ctx
case (ctx, t @ g.ModuleDef(_, _, _)) => decode(t) :: ctx
case (ctx, t @ g.TypeDef(_, _, _, _)) => decode(t) :: ctx
case (ctx, t) => ctx
}
val grouped =
symbols.distinct
.groupBy{case (a, b, c, d) => (b, c, d) }
.mapValues(_.map(_._1))
val open = for {
((fromName, toName, importString), items) <- grouped
if !CompilerUtil.ignoredNames(fromName)
} yield {
val importType = items match{
case Seq(true) => ImportData.Type
case Seq(false) => ImportData.Term
case Seq(_, _) => ImportData.TermType
}
ImportData(Name(fromName), Name(toName), importString, importType)
}
// Send the recorded imports through a callback back to the Ammonite REPL.
// Make sure we sort the imports according to their prefix, so that when
// they later get rendered the same-prefix imports can be collapsed
// together v.s. having them by sent in the arbitrary-jumbled order they
// come out of the `grouped` map in
output(open.toVector.sortBy(x => Util.encodeScalaSourcePath(x.prefix)))
}
}
object LineNumberModifier {
def apply(g: Global)(unit: g.CompilationUnit,
topWrapperLen: => Int) = {
object LineNumberCorrector extends g.Transformer {
import scala.reflect.internal.util._
private val trimmedSource = new BatchSourceFile(g.currentSource.file,
g.currentSource.content.drop(topWrapperLen))
override def transform(tree: g.Tree) = {
val transformedTree = super.transform(tree)
// The `start` and `end` values in transparent/range positions are left
// untouched, because of some aggressive validation in scalac that checks
// that trees are not overlapping, and shifting these values here
// violates the invariant (which breaks Ammonite, potentially because
// of multi-stage).
// Moreover, we rely only on the "point" value (for error reporting).
// The ticket https://github.com/scala/scala-dev/issues/390 tracks down
// relaxing the aggressive validation.
val newPos = tree.pos match {
case s : TransparentPosition if s.start > topWrapperLen =>
new TransparentPosition(
trimmedSource,
s.start - topWrapperLen,
s.point - topWrapperLen,
s.end - topWrapperLen
)
case s: RangePosition if s.start > topWrapperLen =>
new RangePosition(
trimmedSource,
s.start - topWrapperLen,
s.point - topWrapperLen,
s.end - topWrapperLen
)
case s: OffsetPosition if s.start > topWrapperLen =>
new OffsetPosition(trimmedSource, s.point - topWrapperLen)
case s => s
}
transformedTree.pos = newPos
transformedTree
}
def apply(unit: g.CompilationUnit) = transform(unit.body)
}
unit.body = LineNumberCorrector(unit)
}
}
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