Handle secondary constructor

Author: liufengyun

compiler/src/dotty/tools/dotc/transform/init/ParamOverridingCheck.scala

@@ -12,7 +12,7 @@ import util.Property
 
 import ast.tpd.*
 import config.Printers.init as printer
-import reporting.trace.force as log
+import reporting.trace as log
 
 import Semantic.Arg
 import Semantic.NewExpr
@@ -131,7 +131,7 @@ object ParamOverridingCheck:
         else
           ddef.rhs match
           case Block(Call(ref, argss) :: _, _) =>
-            val args = evalArgs(argss.flatten, thisV, thisV.klass)
+            val args = evalArgs(argss.flatten, thisV, cls)
             thisV.callConstructor(ref.symbol, args)
 
     }
@@ -215,7 +215,16 @@ object ParamOverridingCheck:
         Skolem(source)
 
       case tmref: TermRef if tmref.prefix == NoPrefix =>
-        Unknown(source)
+        val sym = tmref.symbol
+
+        if sym.is(Flags.Param) && sym.owner.isConstructor then
+          val enclosingClass = sym.owner.enclosingClass.asClass
+          if enclosingClass == klass then
+            thisV.field(sym)
+          else
+            Unknown(source)
+        else
+          Unknown(source)
 
       case tmref: TermRef =>
         val cls = tmref.widenSingleton.classSymbol

tests/init/pos/i15764b.scala

@@ -0,0 +1,8 @@
+class A(val y: Int):
+  println(y)                   // should not issue a warning here
+  foo()
+  def foo() = println(y)
+
+class B(z: Int) extends A(z)
+
+class C(override val y: Int) extends B(y)

tests/init/pos/i15764c.scala

@@ -0,0 +1,9 @@
+class A(val y: Int):
+  println(y)                   // should not issue a warning here
+  foo()
+  def foo() = println(y)
+
+class B(m: Int, n: Int) extends A(m):
+  def this(z: Int) = this(z, z)
+
+class C(override val y: Int) extends B(y)