Merge pull request #1850 from dotty-staging/fix-#1845

odersky · web-flow · commit 39c27b6a8aaa · 2016-12-28T10:35:03.000+07:00
Fix #1845: Survive illegal this-type prefixes
diff --git a/compiler/src/dotty/tools/dotc/typer/TypeAssigner.scala b/compiler/src/dotty/tools/dotc/typer/TypeAssigner.scala
@@ -282,7 +282,9 @@ trait TypeAssigner {
 
   def assignType(tree: untpd.This)(implicit ctx: Context) = {
     val cls = qualifyingClass(tree, tree.qual.name, packageOK = false)
-    tree.withType(cls.thisType)
+    tree.withType(
+        if (cls.isClass) cls.thisType
+        else errorType("not a legal qualifying class for this", tree.pos))
   }
 
   def assignType(tree: untpd.Super, qual: Tree, inConstrCall: Boolean, mixinClass: Symbol = NoSymbol)(implicit ctx: Context) = {
diff --git a/tests/neg/i1845.scala b/tests/neg/i1845.scala
@@ -0,0 +1,3 @@
+object Test {
+  type X = FooBar22.this // error
+} // error

Original file line number	Diff line number	Diff line change
`@@ -282,7 +282,9 @@ trait TypeAssigner {`
`282`	`282`
`283`	`283`	`def assignType(tree: untpd.This)(implicit ctx: Context) = {`
`284`	`284`	`val cls = qualifyingClass(tree, tree.qual.name, packageOK = false)`
`285`		`- tree.withType(cls.thisType)`
	`285`	`+ tree.withType(`
	`286`	`+ if (cls.isClass) cls.thisType`
	`287`	`+ else errorType("not a legal qualifying class for this", tree.pos))`
`286`	`288`	`}`
`287`	`289`
`288`	`290`	`def assignType(tree: untpd.Super, qual: Tree, inConstrCall: Boolean, mixinClass: Symbol = NoSymbol)(implicit ctx: Context) = {`