1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
|
package dotty.tools.dotc
package transform
import core._
import Names._
import dotty.tools.dotc.transform.TreeTransforms.{AnnotationTransformer, TransformerInfo, MiniPhaseTransform, TreeTransformer}
import ast.Trees._
import Flags._
import Types._
import Constants.Constant
import Contexts.Context
import Symbols._
import SymDenotations._
import Decorators._
import dotty.tools.dotc.core.Annotations.ConcreteAnnotation
import dotty.tools.dotc.core.Denotations.SingleDenotation
import scala.collection.mutable
import DenotTransformers._
import typer.Checking
import Names.Name
import NameOps._
/** The first tree transform
* - ensures there are companion objects for all classes except module classes
* - eliminates some kinds of trees: Imports, NamedArgs, all TypTrees other than TypeTree
* - converts Select/Ident/SelectFromTypeTree nodes that refer to types to TypeTrees.
* - inserts `.package` for selections of package object members
* - checks the bounds of AppliedTypeTrees
* - stubs out native methods
* - removes java-defined ASTs
*/
class FirstTransform extends MiniPhaseTransform with IdentityDenotTransformer with AnnotationTransformer { thisTransformer =>
import ast.tpd._
override def phaseName = "firstTransform"
def transformInfo(tp: Type, sym: Symbol)(implicit ctx: Context): Type = tp
override def checkPostCondition(tree: Tree)(implicit ctx: Context): Unit = tree match {
case Select(qual, _) if tree.symbol.exists =>
assert(qual.tpe derivesFrom tree.symbol.owner, i"non member selection of ${tree.symbol.showLocated} from ${qual.tpe}")
case _: TypeTree =>
case _: Import | _: NamedArg | _: TypTree =>
assert(false, i"illegal tree: $tree")
case _ =>
}
/** Reorder statements so that module classes always come after their companion classes, add missing companion classes */
private def reorderAndComplete(stats: List[Tree])(implicit ctx: Context): List[Tree] = {
val moduleClassDefs, singleClassDefs = mutable.Map[Name, Tree]()
def reorder(stats: List[Tree]): List[Tree] = stats match {
case (stat: TypeDef) :: stats1 if stat.symbol.isClass =>
if (stat.symbol is Flags.Module) {
moduleClassDefs += (stat.name -> stat)
singleClassDefs -= stat.name.stripModuleClassSuffix
val stats1r = reorder(stats1)
if (moduleClassDefs contains stat.name) stat :: stats1r else stats1r
} else {
def stats1r = reorder(stats1)
val normalized = moduleClassDefs remove stat.name.moduleClassName match {
case Some(mcdef) =>
mcdef :: stats1r
case None =>
singleClassDefs += (stat.name -> stat)
stats1r
}
stat :: normalized
}
case stat :: stats1 => stat :: reorder(stats1)
case Nil => Nil
}
def newCompanion(name: TermName): Thicket = {
val modul = ctx.newCompleteModuleSymbol(ctx.owner, name, Synthetic, Synthetic,
defn.ObjectClass.typeRef :: Nil, Scopes.newScope)
if (ctx.owner.isClass) modul.enteredAfter(thisTransformer)
ModuleDef(modul, Nil)
}
def addMissingCompanions(stats: List[Tree]): List[Tree] = stats map {
case stat: TypeDef if singleClassDefs contains stat.name =>
Thicket(stat :: newCompanion(stat.name.toTermName).trees)
case stat => stat
}
def skipJava(stats: List[Tree]): List[Tree] = // packages get a JavaDefined flag. Dont skip them
stats.filter(t => !(t.symbol is(Flags.JavaDefined, Flags.Package)))
addMissingCompanions(reorder(skipJava(stats)))
}
override def transformDefDef(ddef: DefDef)(implicit ctx: Context, info: TransformerInfo) = {
if (ddef.symbol.hasAnnotation(defn.NativeAnnot)) {
ddef.symbol.resetFlag(Deferred)
DefDef(ddef.symbol.asTerm,
_ => ref(defn.Sys_error).withPos(ddef.pos)
.appliedTo(Literal(Constant("native method stub"))))
} else ddef
}
override def transformStats(trees: List[Tree])(implicit ctx: Context, info: TransformerInfo): List[Tree] =
ast.Trees.flatten(reorderAndComplete(trees)(ctx.withPhase(thisTransformer.next)))
private def normalizeType(tree: Tree)(implicit ctx: Context) =
if (tree.isType) TypeTree(tree.tpe).withPos(tree.pos) else tree
override def transformIdent(tree: Ident)(implicit ctx: Context, info: TransformerInfo) = tree.tpe match {
case tpe: ThisType =>
/*
A this reference hide in a self ident, and be subsequently missed
when deciding on whether outer accessors are needed and computing outer paths.
sWe do this normalization directly after Typer, because during typer the
ident should rest available for hyperlinking.*/
This(tpe.cls).withPos(tree.pos)
case _ => normalizeType(tree)
}
override def transformSelect(tree: Select)(implicit ctx: Context, info: TransformerInfo) =
normalizeType {
val qual = tree.qualifier
qual.symbol.moduleClass.denot match {
case pkg: PackageClassDenotation if tree.symbol.maybeOwner.isPackageObject =>
cpy.Select(tree)(qual select pkg.packageObj.symbol, tree.name)
case _ =>
tree
}
}
override def transformSelectFromTypeTree(tree: SelectFromTypeTree)(implicit ctx: Context, info: TransformerInfo) =
normalizeType(tree)
override def transformOther(tree: Tree)(implicit ctx: Context, info: TransformerInfo) = tree match {
case tree: Import => EmptyTree
case tree: NamedArg => transform(tree.arg)
case AppliedTypeTree(tycon, args) =>
val tparams = tycon.tpe.typeSymbol.typeParams
val bounds = tparams.map(tparam =>
tparam.info.asSeenFrom(tycon.tpe.normalizedPrefix, tparam.owner.owner).bounds)
def instantiateUpperBound(tp: Type, argTypes: List[Type]): Type = {
tp.substDealias(tparams, argTypes).bounds.hi
// not that argTypes can contain a TypeBounds type for arguments that are
// not fully determined. In that case we need to check against the hi bound.
}
Checking.checkBounds(args, bounds, instantiateUpperBound)
normalizeType(tree)
case tree =>
normalizeType(tree)
}
// invariants: all modules have companion objects
// all types are TypeTrees
// all this types are explicit
}
|
