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bishaboshabishabosha
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fix #14432: check if scala 2 case class is accessible
1 parent d484926 commit d6e17a2

22 files changed

+261
-3
lines changed

‎compiler/src/dotty/tools/dotc/typer/Synthesizer.scala

+24-3
Original file line numberDiff line numberDiff line change
@@ -283,6 +283,22 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
283283
case OrType(tp1, tp2) => acceptable(tp1, cls) && acceptable(tp2, cls)
284284
case _ => tp.classSymbol eq cls
285285

286+
/** for a case class, if it will have an anonymous mirror,
287+
* check that its constructor can be accessed
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* from the calling scope.
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*/
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def canAccessCtor(cls: Symbol): Boolean =
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!genAnonyousMirror(cls) || {
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def isAccessible(sym: Symbol): Boolean = ctx.owner.isContainedIn(sym)
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def isSub(sym: Symbol): Boolean = ctx.owner.ownersIterator.exists(_.derivesFrom(sym))
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val ctor = cls.primaryConstructor
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(!ctor.isOneOf(Private | Protected) || isSub(cls)) // we cant access the ctor because we do not extend cls
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&& (!ctor.privateWithin.exists || isAccessible(ctor.privateWithin)) // check scope is compatible
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}
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def genAnonyousMirror(cls: Symbol): Boolean =
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cls.is(Scala2x) || cls.linkedClass.is(Case)
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286302
def makeProductMirror(cls: Symbol): Tree =
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val accessors = cls.caseAccessors.filterNot(_.isAllOf(PrivateLocal))
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val elemLabels = accessors.map(acc => ConstantType(Constant(acc.name.toString)))
@@ -300,7 +316,7 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
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.refinedWith(tpnme.MirroredElemTypes, TypeAlias(elemsType))
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.refinedWith(tpnme.MirroredElemLabels, TypeAlias(elemsLabels))
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val mirrorRef =
303-
if (cls.is(Scala2x) || cls.linkedClass.is(Case)) anonymousMirror(monoType, ExtendsProductMirror, span)
319+
if (genAnonyousMirror(cls)) anonymousMirror(monoType, ExtendsProductMirror, span)
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else companionPath(mirroredType, span)
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mirrorRef.cast(mirrorType)
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end makeProductMirror
@@ -321,8 +337,13 @@ class Synthesizer(typer: Typer)(using @constructorOnly c: Context):
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modulePath.cast(mirrorType)
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else
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val cls = mirroredType.classSymbol
324-
if acceptable(mirroredType, cls) && cls.isGenericProduct then makeProductMirror(cls)
325-
else EmptyTree
340+
if acceptable(mirroredType, cls)
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&& cls.isGenericProduct
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&& canAccessCtor(cls)
343+
then
344+
makeProductMirror(cls)
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else
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EmptyTree
326347
end productMirror
327348

328349
private def sumMirror(mirroredType: Type, formal: Type, span: Span)(using Context): Tree =

‎sbt-test/scala2-compat/i14432/app1fail/Test.scala

+3
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,3 @@
1+
import deriving.Mirror
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val mFoo = summon[Mirror.Of[Foo]] // error: `Foo.<init>(Int)` is not accessible from `<empty>`.

‎sbt-test/scala2-compat/i14432/app1ok/Test.scala

+8
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,8 @@
1+
import deriving.Mirror
2+
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package example {
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val mFoo = summon[Mirror.Of[Foo]] // ok, we can access Foo's ctor from here.
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}
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@main def Test: Unit =
8+
assert(example.mFoo.fromProduct(Some(23)) == example.Foo(23))

‎sbt-test/scala2-compat/i14432/app2fail/Test.scala

+5
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,5 @@
1+
package example
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import deriving.Mirror
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val mFoo = summon[Mirror.Of[Foo]] // error: `Foo.<init>(Int)` is not accessible from any class.

‎sbt-test/scala2-compat/i14432/build.sbt

+30
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@@ -0,0 +1,30 @@
1+
val scala3Version = sys.props("plugin.scalaVersion")
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val scala2Version = sys.props("plugin.scala2Version")
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lazy val lib1 = project.in(file("lib1"))
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.settings(
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scalaVersion := scala2Version
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)
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9+
lazy val lib2 = project.in(file("lib2"))
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.settings(
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scalaVersion := scala2Version
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)
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lazy val app1fail = project.in(file("app1fail"))
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.dependsOn(lib1)
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.settings(
17+
scalaVersion := scala3Version
18+
)
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lazy val app1ok = project.in(file("app1ok"))
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.dependsOn(lib1)
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.settings(
23+
scalaVersion := scala3Version
24+
)
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26+
lazy val app2fail = project.in(file("app2fail"))
27+
.dependsOn(lib2)
28+
.settings(
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scalaVersion := scala3Version
30+
)

‎sbt-test/scala2-compat/i14432/lib1/Foo.scala

+3
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@@ -0,0 +1,3 @@
1+
package example
2+
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case class Foo private[example] (i: Int)

‎sbt-test/scala2-compat/i14432/lib2/Foo.scala

+3
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@@ -0,0 +1,3 @@
1+
package example
2+
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case class Foo private (i: Int)

‎sbt-test/scala2-compat/i14432/test

+5
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@@ -0,0 +1,5 @@
1+
> lib1/compile
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> lib2/compile
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-> app1fail/compile
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> app1ok/run
5+
-> app2fail/compile

‎tests/neg/i14432.check

+4
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@@ -0,0 +1,4 @@
1+
-- Error: tests/neg/i14432.scala:13:33 ---------------------------------------------------------------------------------
2+
13 |val mFoo = summon[Mirror.Of[Foo]] // error: no mirror found
3+
| ^
4+
|no given instance of type deriving.Mirror.Of[example.Foo] was found for parameter x of method summon in object Predef

‎tests/neg/i14432.scala

+13
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,13 @@
1+
package example
2+
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import deriving.Mirror
4+
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case class Foo private (i: Int)
6+
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// case object companion here prevents Foo from caching
8+
// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
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case object Foo
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// however we can not provide an anonymous mirror
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// at this call site because the constructor is not accessible.
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val mFoo = summon[Mirror.Of[Foo]] // error: no mirror found

‎tests/neg/i14432a.check

+4
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,4 @@
1+
-- Error: tests/neg/i14432a.scala:14:43 --------------------------------------------------------------------------------
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14 | val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror found
3+
| ^
4+
|no given instance of type deriving.Mirror.Of[example.Foo] was found for parameter x of method summon in object Predef

‎tests/neg/i14432a.scala

+15
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,15 @@
1+
import deriving.Mirror
2+
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package example {
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case class Foo private[example] (val i: Int)
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// case object companion here prevents Foo from caching
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// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
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case object Foo
9+
}
10+
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@main def Test: Unit =
12+
// however we can not provide an anonymous mirror
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// at this call site because the constructor is not accessible.
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val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror found
15+
assert(mFoo.fromProduct(Tuple1(1)).i == 1)

‎tests/neg/i14432b.check

+4
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,4 @@
1+
-- Error: tests/neg/i14432b.scala:15:43 --------------------------------------------------------------------------------
2+
15 | val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror found
3+
| ^
4+
|no given instance of type deriving.Mirror.Of[example.Foo] was found for parameter x of method summon in object Predef

‎tests/neg/i14432b.scala

+16
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,16 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo protected [example] (val i: Int)
5+
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// case object companion here prevents Foo from caching
7+
// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
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case object Foo
9+
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}
11+
12+
class Bar extends example.Foo(23) {
13+
// however we can not provide an anonymous mirror
14+
// at this call site because the constructor is not accessible.
15+
val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror found
16+
}

‎tests/neg/i14432c.check

+12
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@@ -0,0 +1,12 @@
1+
-- Error: tests/neg/i14432c.scala:12:18 --------------------------------------------------------------------------------
2+
12 |class Bar extends example.Foo(23) { // error // error: cant access private[example] ctor
3+
| ^^^^^^^^^^^
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| constructor Foo cannot be accessed as a member of example.Foo from class Bar.
5+
-- Error: tests/neg/i14432c.scala:12:6 ---------------------------------------------------------------------------------
6+
12 |class Bar extends example.Foo(23) { // error // error: cant access private[example] ctor
7+
| ^
8+
| constructor Foo cannot be accessed as a member of example.Foo from class Bar.
9+
-- Error: tests/neg/i14432c.scala:16:43 --------------------------------------------------------------------------------
10+
16 | val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror
11+
| ^
12+
|no given instance of type deriving.Mirror.Of[example.Foo] was found for parameter x of method summon in object Predef

‎tests/neg/i14432c.scala

+18
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,18 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo private [example] (val i: Int)
5+
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// case object companion here prevents Foo from caching
7+
// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
8+
case object Foo
9+
10+
}
11+
12+
class Bar extends example.Foo(23) { // error // error: cant access private[example] ctor
13+
14+
// however we can not provide an anonymous mirror
15+
// at this call site because the constructor is not accessible.
16+
val mFoo = summon[Mirror.Of[example.Foo]] // error: no mirror
17+
18+
}

‎tests/neg/i14432d.check

+4
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,4 @@
1+
-- Error: tests/neg/i14432d.scala:17:45 --------------------------------------------------------------------------------
2+
17 | val mFoo = summon[Mirror.Of[example.Foo]] // error
3+
| ^
4+
|no given instance of type deriving.Mirror.Of[example.Foo] was found for parameter x of method summon in object Predef

‎tests/neg/i14432d.scala

+20
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,20 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo protected [example] (val i: Int)
5+
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// case object companion here prevents Foo from caching
7+
// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
8+
case object Foo
9+
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}
11+
12+
class Bar extends example.Foo(23) {
13+
14+
class Inner {
15+
// however we can not provide an anonymous mirror
16+
// at this call site because the constructor is not accessible.
17+
val mFoo = summon[Mirror.Of[example.Foo]] // error
18+
}
19+
20+
}

‎tests/run/i14432.scala

+11
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,11 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
// Foo caches the mirror in its companion,
5+
// which can still access the constructor.
6+
case class Foo private (val i: Int)
7+
}
8+
9+
@main def Test: Unit =
10+
val mFoo = summon[Mirror.Of[example.Foo]]
11+
assert(mFoo.fromProduct(Tuple1(1)).i == 1)

‎tests/run/i14432a.scala

+16
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@@ -0,0 +1,16 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo private[example] (val i: Int)
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// case object companion here prevents Foo from caching
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// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
8+
case object Foo
9+
10+
// here, we can synthesize an anonymous mirror
11+
// because at this call site the constructor is accessible.
12+
val mFoo = summon[Mirror.Of[example.Foo]]
13+
}
14+
15+
@main def Test: Unit =
16+
assert(example.mFoo.fromProduct(Tuple1(1)).i == 1)

‎tests/run/i14432b.scala

+20
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@@ -0,0 +1,20 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo protected [example] (val i: Int)
5+
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// case object companion here prevents Foo from caching
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// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
8+
case object Foo
9+
10+
class Bar extends Foo(23) {
11+
// here, we can synthesize an anonymous mirror
12+
// because at this call site the constructor is accessible.
13+
val mFoo = summon[Mirror.Of[example.Foo]]
14+
}
15+
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}
17+
18+
@main def Test: Unit =
19+
val bar = new example.Bar
20+
assert(bar.mFoo.fromProduct(Tuple1(1)).i == 1)

‎tests/run/i14432c.scala

+23
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,23 @@
1+
import deriving.Mirror
2+
3+
package example {
4+
case class Foo protected [example] (val i: Int)
5+
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// case object companion here prevents Foo from caching
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// the mirror in its companion, so all potential mirrors for Foo will be anonymous.
8+
case object Foo
9+
10+
class Bar extends Foo(23) {
11+
class Inner {
12+
// here, we can synthesize an anonymous mirror
13+
// because at this call site the constructor is accessible.
14+
val mFoo = summon[Mirror.Of[example.Foo]]
15+
}
16+
val inner = Inner()
17+
}
18+
19+
}
20+
21+
@main def Test: Unit =
22+
val bar = new example.Bar
23+
assert(bar.inner.mFoo.fromProduct(Tuple1(1)).i == 1)

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