Overcome Name comparison hurdles

Author: som-snytt

compiler/src/dotty/tools/dotc/core/NameOps.scala

@@ -188,9 +188,17 @@ object NameOps{
  }
  }
 
-/** Do two target names match? An empty target name matchws any other name. */
+/** Do two target names match? An empty target name matches any other name.
+ * Target names match if their simple names compare equal,
+ * if they belong to the same term or type namespace,
+ * and it's not the case that only one is a field name.
+*/
 defmatchesTargetName(other: Name) =
- name == other || name.isEmpty || other.isEmpty
+ name.isEmpty
+|| other.isEmpty
+|| name.isTermName == other.isTermName
+&& name.is(NameKinds.FieldName) == other.is(NameKinds.FieldName)
+&& name.toSimpleName == other.toSimpleName
 
 privatedeffunctionSuffixStart:Int=
 valfirst= name.firstPart

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

@@ -1344,11 +1344,12 @@ trait Checking{
 
 /** Check that class does not declare same symbol twice */
 defcheckNoDoubleDeclaration(cls: Symbol)(usingContext):Unit=
-valseen=new mutable.HashMap[Name, List[Symbol]].withDefaultValue(Nil)
+valseen=new mutable.HashMap[String, List[Symbol]].withDefaultValue(Nil)
  typr.println(i"check no double declarations $cls")
 
 defcheckDecl(decl: Symbol):Unit=
-for other <- seen(decl.name) if decl.name != nme.ERROR&&!decl.isAbsent() &&!other.isAbsent() do
+valkey= decl.name.toString
+for other <- seen(key) if decl.name != nme.ERROR&&!decl.isAbsent() &&!other.isAbsent() do
  typr.println(i"conflict? $decl$other")
 defjavaFieldMethodPair=
  decl.is(JavaDefined) && other.is(JavaDefined) &&
@@ -1365,7 +1366,7 @@ trait Checking{
  report.error(em"two or more overloaded variants of $decl have default arguments", decl.srcPos)
  decl.resetFlag(HasDefaultParams)
 if!excludeFromDoubleDeclCheck(decl) then
- seen(decl.name) = decl :: seen(decl.name)
+ seen(key) ::=decl
 
  cls.info.decls.foreach(checkDecl)
  cls.info match

tests/neg/i19274.scala

@@ -0,0 +1,13 @@
+importannotation.*
+
+caseclassStaticBinding(v: String){
+privatedefcopy$default$1():String=???// error
+}
+
+caseclassDynamicBinding(v: String):
+@targetName("copy$default$1")
+privatedefdynamo():String=???// TODO
+
+@main defDemo=
+valb=StaticBinding("test")
+ println(b)

tests/pos/i19274.scala

@@ -0,0 +1,13 @@
+//>usingoptions-Ycheck:mixin
+
+objectDiagnostic:
+traitOriginWarning(valorigin:String):
+self: Warning=>
+objectOriginWarning:
+valNoOrigin="..."
+
+classLintWarning(msg: String, origin: String=OriginWarning.NoOrigin)
+extendsWarning(msg), OriginWarning(origin)
+
+classWarning(msg: String) extendsDiagnostic(msg)
+classDiagnostic(valmsg:String)