Merge pull request #9854 from dotty-staging/fix-9766

bishabosha · web-flow · commit 9d09f69a3037 · 2020-09-23T16:55:00.000+02:00
fix #9766: extensions cannot be extension_foo
diff --git a/compiler/src/dotty/tools/dotc/ast/Desugar.scala b/compiler/src/dotty/tools/dotc/ast/Desugar.scala
@@ -945,7 +945,7 @@ object desugar {
       report.error(IllegalRedefinitionOfStandardKind(kind, name), errPos)
       name = name.errorName
     }
-    if name.isExtensionName && !mdef.mods.is(ExtensionMethod) then
+    if name.isExtensionName && (!mdef.mods.is(ExtensionMethod) || name.dropExtension.isExtensionName) then
       report.error(em"illegal method name: $name may not start with `extension_`", errPos)
     name
   }
diff --git a/tests/neg/illegal-extension.scala b/tests/neg/illegal-extension.scala
@@ -1,3 +1,5 @@
 trait A {
   def extension_n: String = "illegal method" // error: illegal method name: extension_n may not start with `extension_`
 }
+
+extension (x: Any) def extension_foo: String = "foo" // error: illegal method name: extension_foo may not start with `extension_`

Original file line number	Diff line number	Diff line change
`@@ -945,7 +945,7 @@ object desugar {`
`945`	`945`	`report.error(IllegalRedefinitionOfStandardKind(kind, name), errPos)`
`946`	`946`	`name = name.errorName`
`947`	`947`	`}`
`948`		`- if name.isExtensionName && !mdef.mods.is(ExtensionMethod) then`
	`948`	`+ if name.isExtensionName && (!mdef.mods.is(ExtensionMethod) \|\| name.dropExtension.isExtensionName) then`
`949`	`949`	report.error(em"illegal method name: $name may not start with `extension_`", errPos)
`950`	`950`	`name`
`951`	`951`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
`1`	`1`	`trait A {`
`2`	`2`	def extension_n: String = "illegal method" // error: illegal method name: extension_n may not start with `extension_`
`3`	`3`	`}`
	`4`	`+`
	`5`	+extension (x: Any) def extension_foo: String = "foo" // error: illegal method name: extension_foo may not start with `extension_`