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author | Mirco Dotta <mirco.dotta@typesafe.com> | 2013-12-12 17:15:48 +0100 |
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committer | Mirco Dotta <mirco.dotta@typesafe.com> | 2014-01-08 12:59:47 +0100 |
commit | 4936c43c137e8e4d133dde397a121288490f78f9 (patch) | |
tree | 464ff2b2c279d6d8ddb4a602e5586075428b5e51 /src/compiler/scala/tools/nsc/typechecker/Typers.scala | |
parent | bdb0ac0fe55260d5ee5e14a963b73bf7d9166430 (diff) | |
download | scala-4936c43c137e8e4d133dde397a121288490f78f9.tar.gz scala-4936c43c137e8e4d133dde397a121288490f78f9.tar.bz2 scala-4936c43c137e8e4d133dde397a121288490f78f9.zip |
SI-4827 Corrected positions assigned to constructor's default arg
* Default arguments are always retained on the <init> method (i.e.,
the class' constructor). Therefore, when the <init> parameters are
created, we need to use `duplicateAndKeepPositions` to make sure that
if a default argument is present, its opaque position is retained as
well. This is necessary because when parameter accessors (i.e.,
`fieldDefs`) are created, all default arguments are discared ( as you
can see in the code, the right-hand-side of a `field` is always an
`EmptyTree`) - see changes in TreeGen.scala
* When constructing the `fieldDefs`, it is important to adapt their
range position to avoid overlappings with the positions of default
arguments. It is worth noting that updating the field's end position
to `vd.rhs.pos.start` would be incorrect, because `askTypeAt(pos)`
could return the incorrect tree when the position is equal to
`vd.rhs.pos.start` (because two nodes including that point position
would exist in the tree, and `CompilerControl.locateTree(pos)` would
return the first tree that includes the passed `pos`). This is why
`1` is subtracted to `vd.rhs.pos.start`. Alternatively, we could have
used `vd.tpt.pos.end` with similar results. However the logic would
have become slightly more complex as we would need to handle the case
where `vd.tpt` doesn't have a range position (for instance, this can
happen if `-Yinfer-argument-types` is enabled). Therefore, subtracting
`1` from `vd.rhs.pos.start` seemed the cleanest solution at the
moment. - see changes in TreeGen.scala.
* If the synthetic constructor contains trees with an opaque range
position (see point above), it must have a transparent position.
This can only happen if the constructor's parameters' positions are
considered, which is why we are now passing `vparamss1` to
`wrappingPos` - see changes in TreeGen.scala.
* The derived primary constructor should have a transparent position
as it may contain trees with an opaque range position. Hence, the
`primaryCtor` position is considered for computing the position of the
derived constructor - see change in Typers.scala.
Finally, below follows the printing of the tree for test t4287, which
you should compare with the one attached with the previous commit
message:
```
[[syntax trees at end of typer]] // Foo.scala
[0:63]package [0:0]<empty> {
[0:37]class Baz extends [9:37][39]scala.AnyRef {
[10:20]<paramaccessor> private[this] val f: [14]Int = _;
[14]<stable> <accessor> <paramaccessor> def f: [14]Int = [14][14]Baz.this.f;
<10:31>def <init>(<10:31>f: [17]<type: [17]scala.Int> = [23:31]B.a): [9]Baz = <10:31>{
<10:31><10:31><10:31>Baz.super.<init>();
<10:31>()
}
};
[6]<synthetic> object Baz extends [6][6]AnyRef {
[6]def <init>(): [9]Baz.type = [6]{
[6][6][6]Baz.super.<init>();
[9]()
};
[14]<synthetic> def <init>$default$1: [14]Int = [30]B.a
};
[39:63]object B extends [48:63][63]scala.AnyRef {
[63]def <init>(): [48]B.type = [63]{
[63][63][63]B.super.<init>();
[48]()
};
[52:61]private[this] val a: [56]Int = [60:61]2;
[56]<stable> <accessor> def a: [56]Int = [56][56]B.this.a
}
}
```
You should notice that the default arg of `Baz` constructor now has a
range position. And that explains why the associated test now returns
the right tree when asking hyperlinking at the location of the default
argument.
Diffstat (limited to 'src/compiler/scala/tools/nsc/typechecker/Typers.scala')
-rw-r--r-- | src/compiler/scala/tools/nsc/typechecker/Typers.scala | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/compiler/scala/tools/nsc/typechecker/Typers.scala b/src/compiler/scala/tools/nsc/typechecker/Typers.scala index 520b55400c..98706d9ea6 100644 --- a/src/compiler/scala/tools/nsc/typechecker/Typers.scala +++ b/src/compiler/scala/tools/nsc/typechecker/Typers.scala @@ -1918,7 +1918,7 @@ trait Typers extends Adaptations with Tags with TypersTracking with PatternTyper val primaryCtor1 = primaryCtor match { case DefDef(_, _, _, _, _, Block(earlyVals :+ global.pendingSuperCall, unit)) => val argss = superArgs(parents1.head) getOrElse Nil - val pos = wrappingPos(parents1.head.pos, argss.flatten) + val pos = wrappingPos(parents1.head.pos, primaryCtor :: argss.flatten).makeTransparent val superCall = atPos(pos)(PrimarySuperCall(argss)) deriveDefDef(primaryCtor)(block => Block(earlyVals :+ superCall, unit) setPos pos) setPos pos case _ => primaryCtor |